WorldWideScience

Sample records for scale biomass heating

  1. Micro scale CHP based on biomass intelligent heat transfer with thermoelectric generators

    Energy Technology Data Exchange (ETDEWEB)

    Moser, W.; Aigenbauer, S.; Heckmann, M.; Friedl, G. (Austrian Bioenergy Centre GmbH, Wieselburg (Austria)); Hofbauer, H. (Institute of Chemical Engineering, Vienna University of Technology (Austria))

    2007-07-01

    Pellet burners need auxiliary electrical power to provide CO{sub 2} balanced heat in a comfortable and environment friendly way. The idea is to produce this and some extra electricity within the device in order to save resources and to gain operation reliability and independency. An option for micro scale CHP is the usage of thermoelectric generators (TEGs). They allow direct conversion of heat into electrical power. They have the advantage of a long maintenance free durability and noiseless operation without moving parts or any working fluid. The useful heat remains almost unaffected and can still be used for heating. TEGs are predestined for the use in micro scale CHP based on solid biomass. In this paper the first results from the fully integrated prototype are presented. The performance of the TEG was observed for different loads and operating conditions in order to realise an optimised micro scale CHP based on solid biomass. (orig.)

  2. Small-scale automated biomass energy heating systems: a viable option for remote Canadian communities?

    Energy Technology Data Exchange (ETDEWEB)

    McCallum, B. [Canadian Forest Service, Ottawa, ON (Canada). Industry, Economics and Programs Branch

    1997-12-31

    The potential benefits of wood energy (forest biomass) for space heating in Canada`s remote communities was discussed. Diesel fuel and heating oil must be transported into these communities to produce electricity and to heat large public buildings. Below the treeline, roundwood is often used to heat private homes. The move toward environmentally sustainable development has focussed much attention on renewable energy technologies such as biomass energy, (i.e. any form of energy derived from plant or animal materials). Wood is the most readily available biomass fuel in remote communities. Woodchips and sawmill waste can be burned in automated biomass heating systems which provide a convenient way to use low-grade wood to heat large buildings or groups of buildings which would not be feasible to heat with roundwood. It was shown that one cord of spruce can produce 1.5 tonnes of woodchips to ultimately displace 300 litres of heating oil. A description of a small-commercial and small-industrial biomass system was presented. The benefits of biomass were described as: (1) direct savings compared to high-cost oil heat, (2) increased circulation of energy dollars inside the community, and (3) employment opportunities in harvesting, processing and operating biomass systems. A steady supply of good quality woodchips to the heating plant must be ensured. 1 ref., 3 figs.

  3. Microenvironmental air quality impact of a commercial-scale biomass heating system.

    Science.gov (United States)

    Tong, Zheming; Yang, Bo; Hopke, Philip K; Zhang, K Max

    2017-01-01

    Initiatives to displace petroleum and climate change mitigation have driven a recent increase in space heating with biomass combustion. However, there is ample evidence that biomass combustion emits significant quantities of health damaging pollutants. We investigated the near-source micro-environmental air quality impact of a biomass-fueled combined heat and power system equipped with an electrostatic precipitator (ESP) in Syracuse, NY. Two rooftop sampling stations with PM2.5 and CO2 analyzers were established in such that one could capture the plume while the other one served as the background for comparison depending on the wind direction. Four sonic anemometers were deployed around the stack to quantify spatially and temporally resolved local wind patterns. Fuel-based emission factors were derived based on near-source measurement. The Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model was then applied to simulate the spatial variations of primary PM2.5 without ESP. Our analysis shows that the absence of ESP could lead to an almost 7 times increase in near-source primary PM2.5 concentrations with a maximum concentration above 100 μg m(-3) at the building rooftop. The above-ground "hotspots" would pose potential health risks to building occupants since particles could penetrate indoors via infiltration, natural ventilation, and fresh air intakes on the rooftop of multiple buildings. Our results demonstrated the importance of emission control for biomass combustion systems in urban area, and the need to take above-ground pollutant "hotspots" into account when permitting distributed generation. The effects of ambient wind speed and stack temperature, the suitability of airport meteorological data on micro-environmental air quality were explored, and the implications on mitigating near-source air pollution were discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Small Scale Gasification of Biomass and Municipal Wastes for Heat and Electricity Production using HTAG Technology

    Directory of Open Access Journals (Sweden)

    Stasiek Jan

    2017-01-01

    Full Text Available Combustion and gasification technology utilizing high-cycle regenerative air/steam preheater has drawn increased attention in many application areas. The process is to be realized at temperature level above ash melting point using highly preheated agent. The use of highly preheated media above 900°C provides additional energy to conversion processes and results in considerable changes to the design of combustion and gasification equipment and its performance. This paper presents an advanced gasification system that utilizes high-temperature air and steam to convert biomass and municipal wastes into syngas production as well as selected results from experimental studies of high temperature air/steam gasification.

  5. Limiting biomass consumption for heating in 100% renewable energy systems

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Connolly, David

    2012-01-01

    -scale solar thermal, large heat pumps, geothermal heat, industrial surplus heat, and waste incineration. Where the energy density in the building stock is not high enough for DH to be economical, geothermal heat pumps can be recommended for individual heating systems, even though biomass consumption is higher......The utilisation of biomass poses large challenges in renewable energy systems while buildings account for a substantial part of the energy supply even in 100% renewable energy systems. In this paper the focus is on how the heating sector can reduce its consumption of biomass, thus leaving biomass...... for other sectors, but while still enabling a 100% renewable energy system. The analyses of heating technologies shows that district heating (DH) systems are important in limiting the dependence on biomass and create cost effective solutions. DH systems are especially important in renewable energy systems...

  6. Particulate and gaseous emissions from different wood fuels during combustion in a small-scale biomass heating system

    Science.gov (United States)

    Olave, R. J.; Forbes, E. G. A.; Johnston, C. R.; Relf, J.

    2017-05-01

    Woodchip is widely used as fuel in dedicated biomass and, even in some conventional energy generation plants. However, there are concerns about atmospheric air pollution from flue gases emitted during wood biomass combustion, particularly oxides of nitrogen (NOx) and particulates Renewable Heat Incentive (RHI), has been introduced. Qualifying criteria for this scheme have included limits for flue gas emissions of NOX and PM10 of 150 and 30 g per gigajoule (g/GJ) of energy input, respectively. In an experiment, three locally available types of Willow (Salix spp) and one of Sitka spruce (Picea sitchensis) woodchips, showed significant differences in physical and chemical constituents, gaseous and particulate emissions. During combustion in a 120 kW biomass system, air flows, flue gas temperatures and energy output correlated with gaseous emissions, NOx with raw fuel ash, nitrogen, phosphorus and potassium content, as did all flue gas particulate fractions. PM10 ranged from 30.3 to 105.7 g/GJ and NOx from 91.2 to 174.3 g/GJ. Sitka spruce produced significantly lower emissions of PM10 and NOx (27.5 and 52.6% less, respectively) than the three willow fuels, from which emissions were above the RHI emissions limits.

  7. Biomass universal district heating systems

    Directory of Open Access Journals (Sweden)

    Soltero Victor Manuel

    2017-01-01

    Full Text Available In mild climate regions Directive 27/2012 EU application for developing sustainable district heating networks in consolidated urban nucleus is a challenge. In Spain most of the municipalities above 5,000 inhabitants have a reliable natural gas network and individual heating systems at homes. In this work a new heating network paradigm is proposed, the biomass universal heating network in rural areas. This model involves all the economic, legal and technical aspects and interactions between the different agents of the systems: provider company, individual and collective end-users and local and regional administration. The continental region in Spain has 588 municipalities with a population above 1,500 inhabitants close to forest biomass with renewable use. In many of these cases the regulation identifies the ownership of the forest resources use. The universal heating networks are a great opportunity for energy saving of 2,000 GWh, avoiding 2.7 million tons of CO2 emissions and with a global annual savings for end users of 61.8 million of euros. The presented model is easily extrapolated to other small municipalities in Europe. The real application of the model is presented for three municipalities in different locations of Spain where Universal Heating Networks are under development. The analysis show the interest of the integrated model for the three cases with different structural agents and relationships between them. The use of sustainable forest resources, extracted and managed by local companies, strengths circular economy in the region with a potential global economic impact above 200 M€.

  8. Biomass universal district heating systems

    Science.gov (United States)

    Soltero, Victor Manuel; Rodríguez-Artacho, Salvador; Velázquez, Ramón; Chacartegui, Ricardo

    2017-11-01

    In mild climate regions Directive 27/2012 EU application for developing sustainable district heating networks in consolidated urban nucleus is a challenge. In Spain most of the municipalities above 5,000 inhabitants have a reliable natural gas network and individual heating systems at homes. In this work a new heating network paradigm is proposed, the biomass universal heating network in rural areas. This model involves all the economic, legal and technical aspects and interactions between the different agents of the systems: provider company, individual and collective end-users and local and regional administration. The continental region in Spain has 588 municipalities with a population above 1,500 inhabitants close to forest biomass with renewable use. In many of these cases the regulation identifies the ownership of the forest resources use. The universal heating networks are a great opportunity for energy saving of 2,000 GWh, avoiding 2.7 million tons of CO2 emissions and with a global annual savings for end users of 61.8 million of euros. The presented model is easily extrapolated to other small municipalities in Europe. The real application of the model is presented for three municipalities in different locations of Spain where Universal Heating Networks are under development. The analysis show the interest of the integrated model for the three cases with different structural agents and relationships between them. The use of sustainable forest resources, extracted and managed by local companies, strengths circular economy in the region with a potential global economic impact above 200 M€.

  9. Electricity and heat production by biomass cogeneration

    Science.gov (United States)

    Marčič, Simon; Marčič, Milan

    2017-07-01

    In Slovenia, approximately 2 % of electricity is generated using cogeneration systems. Industrial and district heating networks ensure the growth of such technology. Today, many existing systems are outdated, providing myriad opportunities for reconstruction. One concept for the development of households and industry envisages the construction of several small biomass units and the application of natural gas as a fuel with a relatively extensive distribution network. This concept has good development potential in Slovenia. Forests cover 56 % of the surface area in Slovenia, which has, as a result, a lot of waste wood to be turned into biomass. Biomass is an important fuel in Slovenia. Biomass is gasified in a gasifier, and the wood gas obtained is used to power the gas engine. This paper describes a biomass cogeneration system as the first of this type in Slovenia, located in Ruše.

  10. Large Scale Solar Heating

    DEFF Research Database (Denmark)

    Heller, Alfred

    2001-01-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors...

  11. A large-scale biomass bulk terminal

    OpenAIRE

    Wu, M.R.

    2012-01-01

    This research explores the possibility of a large-scale bulk terminal in West Europe dedicated to handle solid and liquid biomass materials. Various issues regarding the conceptual design of such a terminal have been investigated and demonstrated in this research: the potential biomass materials that will be the major international trade flows in the future, the characteristics of these potential biomass materials, the interaction between the material properties and terminal equipment, the pe...

  12. Heating technologies for limiting biomass consumption in 100% renewable energy systems

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Connolly, David

    2011-01-01

    district heating enables the use of combined heat and power production (CPH) and other renewable resources than biomass such as large-scale solar thermal, large-heat pumps, geothermal heat, industrial surplus heat etc. which is important for reducing the biomass consumption. Where the energy density......The utilisation of biomass poses large challenges in renewable energy systems and buildings account for a substantial part of the energy supply also in 100% renewable energy systems. The analyses of heating technologies show that district heating systems are especially important in limiting...... the dependence on biomass resources and to create cost effective systems. District heating systems are especially important in renewable energy systems with large amounts of fluctuating renewable energy sources as it enables fuel efficient and lower cost energy systems with thermal heat storages. And also...

  13. A large-scale biomass bulk terminal

    NARCIS (Netherlands)

    Wu, M.R.

    2012-01-01

    This research explores the possibility of a large-scale bulk terminal in West Europe dedicated to handle solid and liquid biomass materials. Various issues regarding the conceptual design of such a terminal have been investigated and demonstrated in this research: the potential biomass materials

  14. Biomass district heating methodology and pilot installations for public buildings groups

    Science.gov (United States)

    Chatzistougianni, N.; Giagozoglou, E.; Sentzas, K.; Karastergios, E.; Tsiamitros, D.; Stimoniaris, D.; Stomoniaris, A.; Maropoulos, S.

    2016-11-01

    The objective of the paper is to show how locally available biomass can support a small-scale district heating system of public buildings, especially when taking into account energy audit in-situ measurements and energy efficiency improvement measures. The step-by-step methodology is presented, including the research for local biomass availability, the thermal needs study and the study for the biomass district heating system, with and without energy efficiency improvement measures.

  15. Investigation of radiative heat transfer in fixed bed biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    T. Klason; X.S. Bai; M. Bahador; T.K. Nilsson; B. Sunden [Lund Institute of Technology, Lund (Sweden). Division of Fluid Mechanics

    2008-08-15

    This paper presents an investigation of the radiative heat transfer process in two fixed bed furnaces firing biomass fuels and the performance of several widely used models for calculation of radiative heat transfer in the free-room of fixed bed furnaces. The effective mean grey gas absorption coefficients are calculated using an optimised version of the exponential wide band model (EWBM) based on an optical mean beam length. Fly-ash and char particles are taken into account using Mie scattering. In the investigated updraft small-scale fixed bed furnace radiative transfer carries heat from the bed to the free-room, whereas in the cross-current bed large-scale industry furnace, radiative transfer brings heat from the hot zones in the free-room to the drying zone of the bed. Not all the investigated models can predict these heat transfer trends, and the sensitivity of results to model parameters is fairly different in the two furnaces. In the small-scale furnace, the gas absorption coefficient predicted by using different optical lengths has great impact on the predicted temperature field. In the large-scale furnaces, the predicted temperature field is less sensitive to the optical length. In both furnaces, with the same radiative properties, the low-computational-cost P1 model predicts a temperature field in the free-room similar to that by the more time consuming SLW model. In general, the radiative heat transfer rates to the fuel bed are not very sensitive to the radiative properties, but they are sensitive to the different radiative heat transfer models. For a realistic prediction of the radiative heat transfer rate to the fuel bed or to the walls, more computationally demanding models such as the FGG or SLW models should be used. 37 refs., 7 figs., 2 tabs.

  16. Development of a bench scale biomass torrefier

    Science.gov (United States)

    Mohd Ja'afar, M. N.; Abd Rahman, A.; Shamsuddin, A. H.

    2013-06-01

    Cofiring biomass with coal has become very popular with power utilities to reduce fossil fuel carbon dioxide (CO2) emission. It is relatively easy to implement on most common pulverised coal plants. However, raw biomass is difficult to utilise and requires upgrading to a higher quality fuel to substitute coal. Upgrading by torrefaction can improve the properties of biomass close to low rank coals suitable for cofiring. In this study, a bench scale torrefier was developed to produce torrefied biomass samples for further studies of its properties and combustion behaviour. The torrefier was developed from a domestic 1600W electric oven. Biomass pellets was then torrefied at 250 °C for 1 hour using this torrefier. Proximate analysis and gross calorific value (GCV) of the torrefied biomass were carried out. The results showed that GCV of the torrefied biomass had increased when compared to raw. The moisture content and volatile matter had decreased, and ash content and fixed carbon had increased as expected.

  17. SMALL SCALE BIOMASS FUELED GAS TURBINE ENGINE

    Science.gov (United States)

    A new generation of small scale (less than 20 MWe) biomass fueled, power plants are being developed based on a gas turbine (Brayton cycle) prime mover. These power plants are expected to increase the efficiency and lower the cost of generating power from fuels such as wood. The n...

  18. Large-scale solar heat

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

    1998-12-31

    In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

  19. Feasibility study of combined heating and cooling by biomass

    OpenAIRE

    Chopo Puertollano, Miguel

    2011-01-01

    PFC del programa Erasmus EPS elaborat a Jyväskylan Ammattikorkeakoulu The main objective was to show the feasibility of biomass in order to produce combined heating and cooling. The energy study of the European heat market and the policy of energy, aims to demonstrate the meaning of the study. Furthermore, the weather in Catalonia is confirming the interest for the topic. Biomass is a renewable energy and this implies a considerable reduction of the pollution. The technical and economical ...

  20. Biomass resources for heat and electricity in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Christou, M.; Panoutsou, C. [Center for Renewable Energy Sources (CRES), Pikermi (Greece); Lychnaras, V. [Agricultural Univ. of Greece, Athens (Greece). Laboratory of Agribusiness Management

    2006-07-15

    }/day corresponding to 5.6 PJ annual energy production.Dedicated energy crops have not been commercially established so far. However, some very promising crops have been investigated in several research and development (RandD) programmes, like cardoon (Cynara cardunculus), giant reed (Arundo donax), miscanthus (Miscanthus x sinensis), switchgrass (Panicum virgatum). Productivity varied considerably with site, climate and soil, species and growing techniques, but yields of over 15 dry matter tones/ha/year appear feasible in most of the Greek regions. The reformed CAP is expected to facilitate the integration of dedicated energy crops in the Greek agriculture. In the present study traditional agricultural biomass resources (crop residues in the field and agro-industrial residues) have been listed and their theoretically available quantities and energy content have been assessed. Quantities used for energy production and fuel prices were also recorded where available. Additionally, yields of dedicated for heat and electricity energy crops were assessed, based on data which are a refinement of actual data collected from small and large scale fields, literature and expert estimations. Their energy content was also determined.Logistics and supply chains for the agricultural and energy crops were recorded and economic assessments were made in order to reveal if integration of energy dedicated crops into the local agricultural systems is feasible under the present circumstances as they are influenced by the reformed CAP and could result to significant social and economic benefits (providing additional income to the farmers or maintaining the present one, maintaining jobs in rural areas, etc.), restructuring thus the stagnant agricultural sector at both national and regional level. (Full text of contribution)

  1. Biomass energy use in small-scale commercial operations

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, K.M. [Carbon Cycle Co., Woodland, CA (United States)

    1999-07-01

    A coffee roasting system using sawdust has been developed by Carbon Cycle, a California Company. They have shown that biomass combustion can be a safe, low-cost alternative to the use of natural gas in a food processing operation. Two systems are in operation with a combined run time of over 80,000 hours. The system uses a patented furnace technology characterized by thermal control to clean combustion, which, when used with biomass, achieves an even, slow roast of raw coffee beans. This results in high-quality coffee flavor. The technology has potential for use in other medium-temperature applications in food processing, district heating, and small-scale energy production. (author)

  2. Biomass equipments. The wood-fueled heating plants; Materiels pour la biomasse. Les chaudieres bois

    Energy Technology Data Exchange (ETDEWEB)

    Chieze, B. [SA Compte R, 63 - Arlanc (France)

    1997-12-31

    This paper analyzes the consequences of the classification of biomass fuels in the French 2910 by-law on the classification of biomass-fueled combustion installations. Biomass fuels used in such installations must be only wood wastes without any treatment or coating. The design of biomass combustion systems must follow several specifications relative to the fueling system, the combustion chamber, the heat exchanger and the treatment of exhaust gases. Other technical solutions must be studied for other type of wood wastes in order to respect the environmental pollution laws. (J.S.)

  3. Biomass gasification in cost-optimized district heating systems-A regional modelling analysis

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Martin, E-mail: martin.borjesson@chalmers.s [Energy Systems Technology, Division of Energy Technology, Department of Energy and Environment, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Ahlgren, Erik O. [Energy Systems Technology, Division of Energy Technology, Department of Energy and Environment, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2010-01-15

    Biomass integrated gasification combined cycle (BIGCC) plants could, in combined heat and power (CHP) generation, increase the power-to-heat ratio compared to conventional biomass steam turbine plants. Furthermore, biomass gasification could also be used for the efficient production of biofuels for transport. In this study, different applications of biomass gasification in connection to district heating (DH) are analysed and contrasted to conventional technology options. An application of the cost-optimizing energy system model MARKAL with a detailed description of the DH sector in a southwestern region of Sweden was developed within the study and used in the analysis. Policy measures for CO{sub 2} reduction and for promotion of 'green' electricity are assumed, and required subsidy levels for large-scale production of transport biofuels are calculated. The model also operates with different supplies of biomass: a local supply at a lower cost and an international supply of refined biomass at a slightly higher cost. The study shows that investments in BIGCC CHP are often cost-efficient in cases with low ambitions regarding transport biofuels. However, due to limitations in heat demand and in local, lower cost, supply of biomass, investment in biofuel production means less investment in BIGCC CHP and, thereby, a smaller electricity production.

  4. Biomass gasification in cost-optimized district heating systems. A regional modelling analysis

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Martin; Ahlgren, Erik O. [Energy Systems Technology, Division of Energy Technology, Department of Energy and Environment, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2010-01-15

    Biomass integrated gasification combined cycle (BIGCC) plants could, in combined heat and power (CHP) generation, increase the power-to-heat ratio compared to conventional biomass steam turbine plants. Furthermore, biomass gasification could also be used for the efficient production of biofuels for transport. In this study, different applications of biomass gasification in connection to district heating (DH) are analysed and contrasted to conventional technology options. An application of the cost-optimizing energy system model MARKAL with a detailed description of the DH sector in a southwestern region of Sweden was developed within the study and used in the analysis. Policy measures for CO{sub 2} reduction and for promotion of 'green' electricity are assumed, and required subsidy levels for large-scale production of transport biofuels are calculated. The model also operates with different supplies of biomass: a local supply at a lower cost and an international supply of refined biomass at a slightly higher cost. The study shows that investments in BIGCC CHP are often cost-efficient in cases with low ambitions regarding transport biofuels. However, due to limitations in heat demand and in local, lower cost, supply of biomass, investment in biofuel production means less investment in BIGCC CHP and, thereby, a smaller electricity production. (author)

  5. The emissions from a space-heating biomass stove

    Energy Technology Data Exchange (ETDEWEB)

    Koyuncu, T.; Pinar, Y. [Agricultural Machinery Department, Agricultural Faculty, Ondokuz Mayis University, 55139, Samsun (Turkey)

    2007-01-15

    In this paper, the flue gas emissions of carbon monoxide (CO), nitrogen oxides (NO{sub X}), sulphur dioxide (SO{sub 2}) and soot from an improved space-heating biomass stove and thermal efficiency of the stove have been investigated. Various biomass fuels such as firewood, wood shavings, hazelnut shell, walnut shell, peanut shell, seed shell of apricot (sweet and hot seed type), kernel removed corncob, wheat stalk litter (for cattle and sheep pen), cornhusk and maize stalk litter (for cattle pen) and charcoal were burned in the same space-heating biomass stove. Flue gas emissions were recorded during the combustion period at intervals of 5min. It was seen from the results that the flue gas emissions have different values depending on the characteristics of biomass fuels. Charcoal is the most appropriate biomass fuel for use in the space-heating biomass stoves because its combustion emits less smoke and the thermal efficiency of the stove is approximately 46%. (author)

  6. Fort Carson Building 1860 Biomass Heating Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Hunsberger, Randolph [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tomberlin, Gregg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gaul, Chris [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    As part of the Army Net-Zero Energy Installation program, the Fort Carson Army Base requested that NREL evaluate the feasibility of adding a biomass boiler to the district heating system served by Building 1860. We have also developed an Excel-spreadsheet-based decision support tool--specific to the historic loads served by Building 1860--with which users can perform what-if analysis on gas costs, biomass costs, and other parameters. For economic reasons, we do not recommend adding a biomass system at this time.

  7. Comparative analysis of heat pump and biomass boiler for small detached house heating

    Science.gov (United States)

    Olkowski, Tomasz; Lipiński, Seweryn; Olędzka, Aneta

    2017-10-01

    The purpose of the work is to answer the question - which of the two selected heat sources is more economically beneficial for small detached house: heat pump or biomass boiler fuelled with wood-pellets? The comparative analysis of these sources was carried out to discuss the issue. First, cost of both, equipment and operation of selected heat systems were analysed. Additionally, CO2 emission levels associated with these heat systems were determined. The comparative analysis of the costs of both considered heat systems showed that equipment cost of heat pump system is considerably bigger than the cost of biomass boiler system. The comparison of annual operation costs showed that heat pump operation cost is slightly lower than operation cost of biomass boiler. The analysis of above results shows that lower operation cost of heat pump in comparison with biomass boiler cost lets qualify heat pump as more economically justified only after 38 years of work. For both analysed devices, CO2 emission levels were determined. The considerations take into account the fact that heat pump consumes electricity. It is mostly generated through combustion of coal in Poland. The results show that in Poland biomass boiler can be described as not only more economically justified system but also as considerably more ecological.

  8. Comparative analysis of heat pump and biomass boiler for small detached house heating

    Directory of Open Access Journals (Sweden)

    Olkowski Tomasz

    2017-01-01

    Full Text Available The purpose of the work is to answer the question - which of the two selected heat sources is more economically beneficial for small detached house: heat pump or biomass boiler fuelled with wood-pellets? The comparative analysis of these sources was carried out to discuss the issue. First, cost of both, equipment and operation of selected heat systems were analysed. Additionally, CO2 emission levels associated with these heat systems were determined. The comparative analysis of the costs of both considered heat systems showed that equipment cost of heat pump system is considerably bigger than the cost of biomass boiler system. The comparison of annual operation costs showed that heat pump operation cost is slightly lower than operation cost of biomass boiler. The analysis of above results shows that lower operation cost of heat pump in comparison with biomass boiler cost lets qualify heat pump as more economically justified only after 38 years of work. For both analysed devices, CO2 emission levels were determined. The considerations take into account the fact that heat pump consumes electricity. It is mostly generated through combustion of coal in Poland. The results show that in Poland biomass boiler can be described as not only more economically justified system but also as considerably more ecological.

  9. Financing Biomass Heating Cooperatives:An Overview

    OpenAIRE

    Degenhart, Heinrich

    2010-01-01

    Im vorliegenden Beitrag wird ein Überblick über die Finanzierung von Genossenschaften gegeben, die lokal bzw. regional begrenzt Haushalte mit Wärme aus der Energieerzeugung mit Biomasse versorgen. Analysiert werden Finanzbedarf, Fremd- und Eigenkapitalfinanzierung sowie mögliche Lösungsansätze für das Finanzierungsproblem, das bei größeren Netzen, Wärmeproduktion oder dem Bau und Betrieb von Biogasanlagen auftritt. Als Lösungen werden 1.) die Zerlegung des Vorhabens in selbständige Teilbereic...

  10. Allothermal gasification of biomass using micron size biomass as external heat source.

    Science.gov (United States)

    Cheng, Gong; Li, Qian; Qi, Fangjie; Xiao, Bo; Liu, Shiming; Hu, Zhiquan; He, Piwen

    2012-03-01

    An allothermal biomass gasification system using biomass micron fuel (BMF) as external heat source was developed. In this system, heat supplied to gasifier was generated from combustion of BMF. Biomass feedstock was gasified with steam and then tar in the produced gas was decomposed in a catalytic bed with NiO/γ-Al(2)O(3) catalyst. Finally the production gas was employed as a substitute for civil fuel gas. An overall energy analysis of the system was also investigated. The results showed that the lower heating value of the product gas reached more than 12 MJ/Nm(3). The combusted BMF accounted for 26.8% of the total energy input. Allothermal gasification based on the substituted BMF for conventional energy was an efficient and economical technology to obtain bioenergy. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Port Graham Community Building Biomass Heating Design Project

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Patrick [Port Graham Village Corporation, Anchorage, AK (United States); Sink, Charles [Chugachmiut, Anchorage, Alaska (United States)

    2015-04-30

    Native Village of Port Graham completed preconstruction activities to prepare for construction and operations of a cord wood biomass heating system to five or more community buildings in Port Graham, Alaska. Project Description Native Village of Port Graham (NVPG) completed preconstruction activities that pave the way towards reduced local energy costs through the construction and operations of a cord wood biomass heating system. NVPG plans include installation of a GARN WHS 3200 Boiler that uses cord wood as fuel source. Implementation of the 700,000 Btu per hour output biomass community building heat utility would heat 5-community buildings in Port Graham, Alaska. Heating system is estimated to displace 85% of the heating fuel oil or 5365 gallons of fuel on an annual basis with an estimated peak output of 600,000 Btu per hour. Estimated savings is $15,112.00 per year. The construction cost estimate made to install the new biomass boiler system is estimated $251,693.47 with an additional Boiler Building expansion cost estimated at $97,828.40. Total installed cost is estimated $349,521.87. The WHS 3200 Boiler would be placed inside a new structure at the old community Water Plant Building site that is controlled by NVPG. Design of the new biomass heat plant and hot water loop system was completed by Richmond Engineering, NVPG contractor for the project. A hot water heat loop system running off the boiler is designed to be placed underground on lands controlled by NVPG and stubbed to feed hot water to existing base board heating system in the following community buildings: 1. Anesia Anahonak Moonin Health and Dental Clinic 2. Native Village of Port Graham offices 3. Port Graham Public Safety Building/Fire Department 4. Port Graham Corporation Office Building which also houses the Port Graham Museum and Head Start Center 5. North Pacific Rim Housing Authority Workshop/Old Fire Hall Existing community buildings fuel oil heating systems are to be retro-fitted to

  12. Grate-firing of biomass for heat and power production

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2008-01-01

    bed on the grate, and the advanced secondary air supply (a real breakthrough in this technology) are highlighted for grate-firing systems. Amongst all the issues or problems associated with grate-fired boilers burning biomass, primary pollutant formation and control, deposition formation and corrosion......As a renewable and environmentally friendly energy source, biomass (i.e., any organic non-fossil fuel) and its utilization are gaining an increasingly important role worldwide Grate-firing is one of the main competing technologies in biomass combustion for heat and power production, because it can...... fire a wide range of fuels of varying moisture content, and requires less fuel preparation and handling. The basic objective of this paper is to review the state-of-the-art knowledge on grate-fired boilers burning biomass: the key elements in the firing system and the development, the important...

  13. Biomass District Heat System for Interior Rural Alaska Villages

    Energy Technology Data Exchange (ETDEWEB)

    Wall, William A.; Parker, Charles R.

    2014-09-01

    Alaska Village Initiatives (AVI) from the outset of the project had a goal of developing an integrated village approach to biomass in Rural Alaskan villages. A successful biomass project had to be ecologically, socially/culturally and economically viable and sustainable. Although many agencies were supportive of biomass programs in villages none had the capacity to deal effectively with developing all of the tools necessary to build a complete integrated program. AVI had a sharp learning curve as well. By the end of the project with all the completed tasks, AVI developed the tools and understanding to connect all of the dots of an integrated village based program. These included initially developing a feasibility model that created the capacity to optimize a biomass system in a village. AVI intent was to develop all aspects or components of a fully integrated biomass program for a village. This meant understand the forest resource and developing a sustainable harvest system that included the “right sized” harvest equipment for the scale of the project. Developing a training program for harvesting and managing the forest for regeneration. Making sure the type, quality, and delivery system matched the needs of the type of boiler or boilers to be installed. AVI intended for each biomass program to be of the scale that would create jobs and a sustainable business.

  14. Estimating the Heat of Formation of Foodstuffs and Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, Alan K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-11-23

    Calorie estimates for expressing the energy content of food are common, however they are inadequate for the purpose of estimating the chemically defined heat of formation of foodstuffs for two reasons. First, they assume utilization factors by the body.1,2,3 Second, they are usually based on average values for their components. The best way to solve this problem would be to measure the heat of combustion of each material of interest. The heat of formation can then be calculated from the elemental composition and the heats of formation of CO2, H2O, and SO2. However, heats of combustion are not always available. Sometimes elemental analysis only is available, or in other cases, a breakdown into protein, carbohydrates, and lipids. A simple way is needed to calculate the heat of formation from various sorts of data commonly available. This report presents improved correlations for relating the heats of combustion and formation to the elemental composition, moisture content, and ash content. The correlations are also able to calculate heats of combustion of carbohydrates, proteins, and lipids individually, including how they depend on elemental composition. The starting point for these correlations are relationships commonly used to estimate the heat of combustion of fossil fuels, and they have been modified slightly to agree better with the ranges of chemical structures found in foodstuffs and biomass.

  15. Biomass gasification opportunities in a district heating system

    Energy Technology Data Exchange (ETDEWEB)

    Difs, Kristina; Wetterlund, Elisabeth; Trygg, Louise; Soederstroem, Mats [Division of Energy Systems, Department of Management and Engineering, Linkoeping University, SE-581 83 Linkoeping (Sweden)

    2010-05-15

    This paper evaluates the economic effects and the potential for reduced CO{sub 2} emissions when biomass gasification applications are introduced in a Swedish district heating (DH) system. The gasification applications included in the study deliver heat to the DH network while producing renewable electricity or biofuels. Gasification applications included are: external superheater for steam from waste incineration (waste boost, WB), gas engine CHP (BIGGE), combined cycle CHP (BIGCC) and production of synthetic natural gas (SNG) for use as transportation fuel. Six scenarios are used, employing two time perspectives - short-term and medium-term - and differing in economic input data, investment options and technical system. To evaluate the economic performance an optimisation model is used to identify the most profitable alternatives regarding investments and plant operation while meeting the DH demand. This study shows that introducing biomass gasification in the DH system will lead to economic benefits for the DH supplier as well as reduce global CO{sub 2} emissions. Biomass gasification significantly increases the potential for production of high value products (electricity or SNG) in the DH system. However, which form of investment that is most profitable is shown to be highly dependent on the level of policy instruments for biofuels and renewable electricity. Biomass gasification applications can thus be interesting for DH suppliers in the future, and may be a vital measure to reach the 2020 targets for greenhouse gases and renewable energy, given continued technology development and long-term policy instruments. (author)

  16. Biomass heating--how the benefits stack up.

    Science.gov (United States)

    Turner, Neil

    2012-03-01

    Neil Turner, business development manager at Wood Energy, a specialist supplier of high efficiency automatic biomass boilers throughout the UK and Ireland, and part of the Renewable Energy System (RES) Group, outlines the case for such boilers, and sets out the key considerations for organisations considering investing in a technology he says is now beginning to 'flourish' and gain popularity, thanks largely to the support and incentives for its use provided through the Renewable Heat Incentive (RHI).

  17. Feasibility Analysis For Heating Tribal Buildings with Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Steve Clairmont; Micky Bourdon; Tom Roche; Colene Frye

    2009-03-03

    This report provides a feasibility study for the heating of Tribal buildings using woody biomass. The study was conducted for the Confederated Salish and Kootenai Tribes of the Flathead Reservation in western Montana. S&K Holding Company and TP Roche Company completed the study and worked together to provide the final report. This project was funded by the DOE's Tribal Energy Program.

  18. Gasification technologies for heat and power from biomass

    NARCIS (Netherlands)

    Beenackers, AACM; Maniatis, K; Kaltschmitt, M; Bridgwater, AV

    1997-01-01

    A critical review is presented of biomass gasifier systems presently commercially available or under development. Advantages and possible problem areas are discussed in relation to particular applications. Both large and small scale technologies are reviewed. Catalysed by the EC JOULE and AIR

  19. Pilot projects for the utilization of biomass from paludiculture in integrated biomass heating systems in Mecklenburg-Western Pomerania; Pilotprojekte zur Nutzung von Biomasse aus Paludikultur in integrierten Biomasseheizwerken in Mecklenburg-Vorpommern

    Energy Technology Data Exchange (ETDEWEB)

    Dahms, Tobias [Greifswald Univ. (Germany). Inst. fuer Botanik und Landschaftsoekologie; Schroeder, Christian; Wichtmann, Wendelin

    2012-07-01

    The use of rewetted peatlands (paludiculture, Latin 'palus' = swamp) is a site-adapted alternative to conventional, drainage based use. Land use on wet peatlands opens up new, sustainable biomass potentials. The project, funded by the research fund MV, studies the production and use of pelletized biomass from paludiculture. An experimental pellet boiler will be integrated into the district heating plant of Greifswald. With reed-biomass from areas belonging to the city, the suitability of the biomass for continuous operation is being tested. For this purpose, the biomass will be pelletized in small scale in cooperation with a local farmer and on industrial scale in cooperation with the German Pellets GmbH. Different mono- and mixed pellet variants will be analyzed. Further on, biomass potential analyses are carried out and the pilot project is analysed in terms of environmental performance and economic viability. The demonstration project will examine the opportunities and challenges of using biomass from rewetted peatlands and develop markets. Part of another pilot project is the integration of a boiler for fen biomass into the district heating plant of Malchin. Thereby new distribution channels for local biomass from landscape conservation shall be assessed. The approval of the funding is necessary for the implementation of the projects. (orig.)

  20. Molecular Scale Drivers of Biomass Recalcitrance

    DEFF Research Database (Denmark)

    Selig, Michael Joseph

    The thesis focus on the basic parameters limiting the breakdown of biomass to sugars. There is a multitude of structures and compounds in the plant cell wall which limits the performance of hydrolytic enzymes. In this thesis it is shown how the interactions between water and the cell wall compone...... components can be used as a measure of biomass recalcitrance as well as unspecific bonding of enzymes to the cell wall components. The different states of water in the plant cell wall is presented and discussed in relation to enzyme adsorption and activity....

  1. An assessment of short rotation coppice (SRC) woody biomass to heat greenhouses in southern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D.; Fraleigh, S.; McKenney, D.; Yemshanov, D. [Natural Resources Canada, Sault Ste. Marie, ON (Canada). Canadian Forest Service Great Lakes Forestry Centre

    2008-07-01

    This presentation identified the best options/scenarios for short rotation coppice (SRT) bioenergy systems as an alternative to fossil fuel supply. Research priorities associated with heating greenhouses with SRC woody biomass were also evaluated along with the economic potential of short-rotation forestry systems to supply biomass for energy production. The presentation outlined the key steps in the production of willow biomass crops and provided an overview of a fast-growing hybrid poplar and willow bio-energy plantation located in Claremont, Ontario. Photographs of established treatments were presented. The presentation also discussed the Canadian Forest Service's SRC greenhouse heating model (GHM) which consisted of a spreadsheet-based cost-benefit analysis tool used to evaluate the feasibility of purpose-grown woody biomass for small scale bioenergy systems to replace existing fossil fuel systems. The model considered greenhouse dimensions, thermal resistance factors of materials, construction factors, system factors, local weather conditions, and desired indoor temperature to determine annual heating requirements. A series of charts and graphs depicted model variables and inputs for southern Ontario; results for the internal rate of return, net present value, and payback period; and results of break even fuel prices versus appliance efficiency and growth rate assumptions; sensitivity analysis; and regional analysis. The presentation also discussed the Canadian Forest Service bioeconomic model and geographical distribution of break-even willow prices. It was concluded that future work should consider un-priced potential environmental benefits and carbon offsets. tabs., figs.

  2. Biomass fired small-scale CHP technologies - Present status and possibilities

    Energy Technology Data Exchange (ETDEWEB)

    Konttinen, J. (Univ. of Jyvaeskylae, Jyvaeskylae (Finland), Renewable energy programme), e-mail: jukontti@jyu.fi; Linna, V. (VTT Technical Research Centre of Finland, Jyvaeskylae (Finland)), e-mail: veli.linna@vtt.fi; Uusi-Maahi, I. (Keulink Oy, Keuruu (Finland)), e-mail: ilkka.uusi-maahi@keulink.fi

    2010-07-01

    The competitiveness of biomass-fuelled CHP (Combined Heat and Power) production technologies is rising. Small-scale (or micro-CHP) means power and heat production in the scale of 10...1000 kW{sub e} by combustion or gasification of biomass. A survey about the commercial potential and technologies in Europe of micro-CHP was made by the University of Jyvaeskylae and VTT (Technical Research Centre of Finland). The survey was funded by Keulink Oy and Jyvaeskylae Innovation Oy. According to the results of the literature survey, the most promising technologies for power production are based on so called ORC (Organic Rankine Cycle) and Stirling engines. Woody-type of biomass is the best raw material for these applications. With the small-scale technologies, the power production efficiency can vary in the range of 15...30 % of the biomass thermal input. New innovative technologies for small-scale CHP application of woody biomass are being developed by private companies in Central and Northern Finland. Some of these are presented in more detail. The technologies are either based on combustion or gasification of wood-based biomass. Using the product gas in combustion engines requires cleaning, which can be carried out with innovative dry or wet clearing processes. Dry cleaning is possible with catalysts and wet cleaning with scrubbers. The small-scale CHP technologies offer significant potential in local consumption sites of power and heat, such as greenhouses and farms. So called 'eco-villages' are also being built to demonstrate this potential. The possibilities for producing liquid transport fuels, such as biodiesel, are also discussed in this paper. (orig.)

  3. A comparison of producer gas, biochar, and activated carbon from two distributed scale thermochemical conversion systems used to process forest biomass

    Science.gov (United States)

    Nathaniel Anderson; J. Greg Jones; Deborah Page-Dumroese; Daniel McCollum; Stephen Baker; Daniel Loeffler; Woodam Chung

    2013-01-01

    Thermochemical biomass conversion systems have the potential to produce heat, power, fuels and other products from forest biomass at distributed scales that meet the needs of some forest industry facilities. However, many of these systems have not been deployed in this sector and the products they produce from forest biomass have not been adequately described or...

  4. Large-scale solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

    1998-10-01

    Solar heating market is growing in many European countries and annually installed collector area has exceeded one million square meters. There are dozens of collector manufacturers and hundreds of firms making solar heating installations in Europe. One tendency in solar heating is towards larger systems. These can be roof integrated, consisting of some tens or hundreds of square meters of collectors, or they can be larger centralized solar district heating plants consisting of a few thousand square meters of collectors. The increase of size can reduce the specific investments of solar heating systems, because e.g. the costs of some components (controllers, pumps, and pipes), planning and installation can be smaller in larger systems. The solar heat output can also be higher in large systems, because more advanced technique is economically viable

  5. Biomass for energy - small scale technologies

    Energy Technology Data Exchange (ETDEWEB)

    Salvesen, F.; Joergensen, P.F. [KanEnergi, Rud (Norway)

    1997-12-31

    The bioenergy markets and potential in EU region, the different types of biofuels, the energy technology, and the relevant applications of these for small-scale energy production are reviewed in this presentation

  6. Biomass energy: the scale of the potential resource.

    Science.gov (United States)

    Field, Christopher B; Campbell, J Elliott; Lobell, David B

    2008-02-01

    Increased production of biomass for energy has the potential to offset substantial use of fossil fuels, but it also has the potential to threaten conservation areas, pollute water resources and decrease food security. The net effect of biomass energy agriculture on climate could be either cooling or warming, depending on the crop, the technology for converting biomass into useable energy, and the difference in carbon stocks and reflectance of solar radiation between the biomass crop and the pre-existing vegetation. The area with the greatest potential for yielding biomass energy that reduces net warming and avoids competition with food production is land that was previously used for agriculture or pasture but that has been abandoned and not converted to forest or urban areas. At the global scale, potential above-ground plant growth on these abandoned lands has an energy content representing approximately 5% of world primary energy consumption in 2006. The global potential for biomass energy production is large in absolute terms, but it is not enough to replace more than a few percent of current fossil fuel usage. Increasing biomass energy production beyond this level would probably reduce food security and exacerbate forcing of climate change.

  7. Pilot-scale study of biomass reduction in wastewater treatment.

    Science.gov (United States)

    Wang, Qunhui; Ai, Hengyu; Li, Xuesong; Liu, Haitao; Xie, Weimin

    2007-05-01

    Pilot-scale experiments were continuously carried out for more than 9 months to study the excess biomass reduction effect using a biophase-separation bioreactor, which was designed based on food-chain theory. By separating the biophase in the wastewater treatment system, bacteria, protozoa, and metazoa could be separated from each other and dominated in different microbial communities. After degrading organic matter, bacteria were consumed by protozoa or metazoa in the following process in such a reactor. Thus, both chemical oxygen demand (COD) and biomass were reduced. During the process of treating restaurant wastewater, the excess biomass yield in this biophase-separation technique varied from 0.13 to 0.22 kg/kg COD removed, 50% lower than that from the reference system. Apart from low biomass production, this biophase-separation technique can simultaneously achieve a high COD removal efficiency and improve settleability of biosolids at a hydraulic retention time of 6 to 13 hours.

  8. Logistics, Costs, and GHG Impacts of Utility Scale Cofiring with 20% Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, Richard D.; Cafferty, Kara G.; Nichol, Corrie; Searcy, Erin M.; Westover, Tyler; Wood, Richard; Bearden, Mark D.; Cabe, James E.; Drennan, Corinne; Jones, Susanne B.; Male, Jonathan L.; Muntean, George G.; Snowden-Swan, Lesley J.; Widder, Sarah H.

    2014-07-22

    This report presents the results of an evaluation of utility-scale biomass cofiring in large pulverized coal power plants. The purpose of this evaluation is to assess the cost and greenhouse gas reduction benefits of substituting relatively high volumes of biomass in coal. Two scenarios for cofiring up to 20% biomass with coal (on a lower heating value basis) are presented; (1) woody biomass in central Alabama where Southern Pine is currently produced for the wood products and paper industries, and (2) purpose-grown switchgrass in the Ohio River Valley. These examples are representative of regions where renewable biomass growth rates are high in correspondence with major U.S. heartland power production. While these scenarios may provide a realistic reference for comparing the relative benefits of using a high volume of biomass for power production, this evaluation is not intended to be an analysis of policies concerning renewable portfolio standards or the optimal use of biomass for energy production in the U.S.

  9. Scaling relationship between tree respiration rates and biomass.

    Science.gov (United States)

    Cheng, Dong-Liang; Li, Tao; Zhong, Quan-Lin; Wang, Gen-Xuan

    2010-10-23

    The WBE theory proposed by West, Brown and Enquist predicts that larger plant respiration rate, R, scales to the three-quarters power of body size, M. However, studies on the R versus M relationship for larger plants (i.e. trees larger than saplings) have not been reported. Published respiration rates of field-grown trees (saplings and larger trees) were examined to test this relationship. Our results showed that for larger trees, aboveground respiration rates RA scaled as the 0.82-power of aboveground biomass MA, and that total respiration rates RT scaled as the 0.85-power of total biomass MT, both of which significantly deviated from the three-quarters scaling law predicted by the WBE theory, and which agreed with 0.81-0.84-power scaling of biomass to respiration across the full range of measured tree sizes for an independent dataset reported by Reich et al. (Reich et al. 2006 Nature 439, 457-461). By contrast, R scaled nearly isometrically with M in saplings. We contend that the scaling exponent of plant metabolism is close to unity for saplings and decreases (but is significantly larger than three-quarters) as trees grow, implying that there is no universal metabolic scaling in plants.

  10. Pilot-scale gasification of woody biomass

    Science.gov (United States)

    Thomas Elder; Leslie H. Groom

    2011-01-01

    The gasification of pine and mixed-hardwood chips has been carried out in a pilot-scale system at a range of gas flow rates. Consuming ~17-30 kgh-1 of feedstock, the producer gas was composed of ~200 dm3 m-3 carbon monoxide, 12 dm3 m-3 carbon dioxide, 30 dm3 m-3 methane and 190 dm3 m-3 hydrogen, with an energy content of ~6 MJ m-3 for both feedstocks. It was found that...

  11. Biomass Supply Planning for Combined Heat and Power Plants using Stochastic Programming

    DEFF Research Database (Denmark)

    Guericke, Daniela; Blanco, Ignacio; Morales González, Juan Miguel

    During the last years, the consumption of biomass to produce power and heat has increased due to the new carbon neutral policies. Nowadays, many district heating systems operate their combined heat and power (CHP) plants using different types of biomass instead of fossil fuel, especially to produce......, and heat demand and electricity prices vary drastically during the planning period. Furthermore, the optimal operation of combined heat and power plants has to consider the existing synergies between the power and heating systems while always fulfilling the heat demand of the system. We propose a solution...... method using stochastic optimization to support the biomass supply planning for combined heat and power plants. Our two-phase approach combines mid-term decisions about biomass supply contracts with the short-term decisions regarding the optimal market participation of the producer to ensure...

  12. Biomass gasification for CHP with dry gas cleaning and regenerative heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-01

    Small scale CHP plants based on biomass gasification technologies are generally expensive and not very efficient due to gas quality problems which increase operation and maintenance cost as well as breakdown. To overcome this situation the team has developed, integrated and tested a complete biomass gasification combine heat and power prototype plant of 250 kWth equipped with a specifically developed dry gas cleaning and heat recovery system. The dry gas cleaning device is a simple dry gas regenerative heat exchanger where tars are stopped by condensation but working at a temperature above due point in order to avoid water condensation. Two types of heat particles separation devices have been tested in parallel multi-cyclone and ceramic filters. After several month spent on modelling design, construction and optimisation, a full test campaign of 400 hours continuous monitoring has been done where all working parameters has been monitored and gas cleaning device performances has been assessed. Results have shown: Inappropriateness of the ceramic filters for the small scale unit due to operation cost and too high sensibility of the filters to the operation conditions fluctuating in a wide range, despite a very high particle separation efficiency 99 %; Rather good efficiency of the multi-cyclone 72% but not sufficient for engine safety. Additional conventional filters where necessary for the finest part; Inappropriateness of the dry gas heat exchanger device for tar removal partly due to a low tar content of the syngas generated, below 100 mg/Nm{sup 3} , but also due to their composition which would have imposed, to be really efficient, a theoretical condensing temperature of 89 C below the water condensation temperature. These results have been confirmed by laboratory tests and modelling. However the tar cracking phase have shown very interesting results and proved the feasibility of thermal cracking with full cleaning of the heat exchanger without further mechanical

  13. Biomass gasification in district heating systems - The effect of economic energy policies

    Energy Technology Data Exchange (ETDEWEB)

    Wetterlund, Elisabeth; Soederstroem, Mats [Division of Energy Systems, Department of Management and Engineering, Linkoeping University, SE-581 83 Linkoeping (Sweden)

    2010-09-15

    Biomass gasification is considered a key technology in reaching targets for renewable energy and CO{sub 2} emissions reduction. This study evaluates policy instruments affecting the profitability of biomass gasification applications integrated in a Swedish district heating (DH) system for the medium-term future (around year 2025). Two polygeneration applications based on gasification technology are considered in this paper: (1) a biorefinery plant co-producing synthetic natural gas (SNG) and district heat; (2) a combined heat and power (CHP) plant using integrated gasification combined cycle technology. Using an optimisation model we identify the levels of policy support, here assumed to be in the form of tradable certificates, required to make biofuel production competitive to biomass based electricity generation under various energy market conditions. Similarly, the tradable green electricity certificate levels necessary to make gasification based electricity generation competitive to conventional steam cycle technology, are identified. The results show that in order for investment in the SNG biorefinery to be competitive to investment in electricity production in the DH system, biofuel certificates in the range of 24-42 EUR/MWh are needed. Electricity certificates are not a prerequisite for investment in gasification based CHP to be competitive to investment in conventional steam cycle CHP, given sufficiently high electricity prices. While the required biofuel policy support is relatively insensitive to variations in capital cost, the required electricity certificates show high sensitivity to variations in investment costs. It is concluded that the large capital commitment and strong dependency on policy instruments makes it necessary that DH suppliers believe in the long-sightedness of future support policies, in order for investments in large-scale biomass gasification in DH systems to be realised. (author)

  14. Impact of different national biomass policies on investment costs of biomass district heating plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-01

    The BIO-COST project - co-ordinated by E.V.A. - was funded by the European Commission's THERMIE Type B Programme. The objective of BIO-COST was to analyse the impact of national biomass policies on the investment costs of biomass district heating (DH) plants. The European comparison should help identifying measures to reduce investment costs for biomass DH plants and/or components down to a 'best practice' level. The investigation is based on the comparison of 20 biomass DH plants by country, with Denmark and Sweden having mainly high energy taxes as driver, while Austria and France rely mainly on subsidy systems. The results of BIO-COST show, that governmental policies can have a big impact especially on grid and buildings costs, effecting of course the overall costs of the plant enormously. Emission standards have their effects especially on the costs for technical equipment, however, this fact was not reflected in the BIO-COST data. The results do not show a clear advantage of either the energy tax approach or the subsidy approach: The French subsidy approach leads to fairly low cost levels compared to the Danish tax approach, while the Swedish tax approach seems to yield the lowest cost level. On the other hand the Austrian subsidy approach seems to intercrease investment costs. In principle both the tax as the subsidy approach can lead to the same effect: a project is calculated in such a way, that it just meets economic breakeven. This is typically the case when the project is not carried out by a private enterprise but by an operator aiming at enhanced public welfare (e.g. co-operative, municipality). In this case a subsidy model might yield more possibilities to encourage an economically efficient development, than a tax. Instead of giving subsidies as a fixed percentage of investments they could be adjusted to the actual needs of the project as proven by a standardised calculation. Of course this can create the incentive to expect higher

  15. The role of large‐scale heat pumps for short term integration of renewable energy

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Blarke, Morten; Hansen, Kenneth

    2011-01-01

    In this report the role of large-scale heat pumps in a future energy system with increased renewable energy is presented. The main concepts for large heat pumps in district heating systems are outlined along with the development for heat pump refrigerants. The development of future heat pump...... of biomass consumption as base load in the energy system. Large heat pumps may also contribute to developing future smart energy systems as they can create flexibility between the electricity and heating/cooling sectors. A case study of Denmark in 2020 indicates that large heat pumps can increase fuel...... savings with increased wind power and may additionally lead to economic savings in the range of 1,500-1,700 MDKK in total in the period until 2020. Furthermore, the energy system efficiency may be increased due to large heat pumps replacing boiler production. Finally data sheets for large-scale ammonium...

  16. Micro-Scale Regenerative Heat Exchanger

    Science.gov (United States)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2004-01-01

    A micro-scale regenerative heat exchanger has been designed, optimized and fabricated for use in a micro-Stirling device. Novel design and fabrication techniques enabled the minimization of axial heat conduction losses and pressure drop, while maximizing thermal regenerative performance. The fabricated prototype is comprised of ten separate assembled layers of alternating metal-dielectric composite. Each layer is offset to minimize conduction losses and maximize heat transfer by boundary layer disruption. A grating pattern of 100 micron square non-contiguous flow passages were formed with a nominal 20 micron wall thickness, and an overall assembled ten-layer thickness of 900 microns. Application of the micro heat exchanger is envisioned in the areas of micro-refrigerators/coolers, micropower devices, and micro-fluidic devices.

  17. Biomass Pyrolysis: Comments on Some Sources of Confusions in the Definitions of Temperatures and Heating Rates

    Directory of Open Access Journals (Sweden)

    Jacques Lédé

    2010-04-01

    Full Text Available Biomass pyrolysis is usually characterized on the basis of temperature and heating rate. Unfortunately, these parameters are badly defined in processing reactors as well as in laboratory devices. From the results of simplified models, the present paper points out the significant mistakes that can be made when assuming that the actual temperature and heating rate of reacting biomass particles are the same as those of the external heating medium. The difficulties in defining these two parameters are underlined in both cases of a heat source temperature supposed to be constant or to increase with time.

  18. Simulating Biomass Fast Pyrolysis at the Single Particle Scale

    Energy Technology Data Exchange (ETDEWEB)

    Ciesielski, Peter [National Renewable Energy Laboratory (NREL); Wiggins, Gavin [ORNL; Daw, C Stuart [ORNL; Jakes, Joseph E. [U.S. Forest Service, Forest Products Laboratory, Madison, Wisconsin, USA

    2017-07-01

    Simulating fast pyrolysis at the scale of single particles allows for the investigation of the impacts of feedstock-specific parameters such as particle size, shape, and species of origin. For this reason particle-scale modeling has emerged as an important tool for understanding how variations in feedstock properties affect the outcomes of pyrolysis processes. The origins of feedstock properties are largely dictated by the composition and hierarchical structure of biomass, from the microstructural porosity to the external morphology of milled particles. These properties may be accounted for in simulations of fast pyrolysis by several different computational approaches depending on the level of structural and chemical complexity included in the model. The predictive utility of particle-scale simulations of fast pyrolysis can still be enhanced substantially by advancements in several areas. Most notably, considerable progress would be facilitated by the development of pyrolysis kinetic schemes that are decoupled from transport phenomena, predict product evolution from whole-biomass with increased chemical speciation, and are still tractable with present-day computational resources.

  19. Gasification of pelletized biomass in a pilot scale downdraft gasifier.

    Science.gov (United States)

    Simone, Marco; Barontini, Federica; Nicolella, Cristiano; Tognotti, Leonardo

    2012-07-01

    This work presents a pilot-scale investigation aimed at assessing the feasibility and reliability of biomass pellet gasification. Wood sawdust and sunflower seeds pellets were tested in a 200 kW downdraft gasifier operating with air as gasifying agent. The gasification of pelletized biomass led to rather high and unstable pressure drops, reducing the gasifier productivity and stability. Furthermore the generation of fine residues compromised the operation of wet ash removal systems. On the other hand, good syngas compositions (H(2) 17.2%, N(2) 46.0%, CH(4) 2.5%, CO 21.2%, CO(2) 12.6%, and C(2)H(4) 0.4%), specific gas production (2.2-2.4 N m(3) kg(-1)) and cold gas efficiency (67.7-70.0%) were achieved. For these reasons pelletized biomass should be considered only as complementary fuel in co-gasification with other feedstock. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Small-Scale Combined Heat and Power Plants Using Biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Salomon-Popa, Marianne [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

    2002-11-01

    In this time period where energy supply and climate change are of special concern, biomass-based fuels have attracted much interest due to their plentiful supply and favorable environmental characteristics (if properly managed). The effective capture and continued sustainability of this renewable resource requires a new generation of biomass power plants with high fuel energy conversion. At the same time, deregulation of the electricity market offers new opportunities for small-scale power plants in a decentralized scheme. These two important factors have opened up possibilities for small-scale combined heat and power (CHP) plants based on biofuels. The objective of this pre-study is to assess the possibilities and technical limitations for increased efficiency and energy utilization of biofuels in small size plants (approximately 10 MWe or lower). Various energy conversion technologies are considered and proven concepts for large-scale fossil fuel plants are an especially important area. An analysis has been made to identify the problems, technical limitations and different possibilities as recognized in the literature. Beyond published results, a qualitative survey was conducted to gain first-hand, current knowledge from experts in the field. At best, the survey results together with the results of personal interviews and a workshop on the role of small-scale plants in distributed generation will serve a guideline for future project directions and ideas. Conventional and novel technologies are included in the survey such as Stirling engines, combustion engines, gas turbines, steam turbines, steam motors, fuel cells and other novel technologies/cycles for biofuels. State-of-the-art heat and power plants will be identified to clarify of the advantages and disadvantages as well as possible obstacles for their implementation.

  1. Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

    Science.gov (United States)

    Zhang, Yifei; Kang, Jian

    2017-11-01

    The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity

  2. BIOMASS PYROLYSIS KINETICS: A REVIEW OF MOLECULAR-SCALE MODELING CONTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    J. D. Murillo

    Full Text Available Abstract Decades of classical research on pyrolysis of lignocellulosic biomass has not yet produced a generalized formalism for design and prediction of reactor performance. Plagued by the limitations of experimental techniques such as thermogravimetric analysis (TGA and extremely fast heating rates and low residence times to achieve high conversion to useful liquid products, researchers are now turning to molecular modeling to gain insights. This contribution briefly summarizes prior reviews along the historical path towards kinetic modeling of biomass pyrolysis and focusses on the more recent work on molecular modeling and the associated experimental efforts to validate model predictions. Clearly a new era of molecular-scale modeling-driven inquiry is beginning to shape the research landscape and influence the description of how cellulose and associated hemicellulose and lignin depolymerize to form the many hundreds of potential products of pyrolysis.

  3. Pyrolysis of corn stalk biomass briquettes in a scaled-up microwave technology.

    Science.gov (United States)

    Salema, Arshad Adam; Afzal, Muhammad T; Bennamoun, Lyes

    2017-06-01

    Pyrolysis of corn stalk biomass briquettes was carried out in a developed microwave (MW) reactor supplied with 2.45GHz frequency using 3kW power generator. MW power and biomass loading were the key parameters investigated in this study. Highest bio-oil, biochar, and gas yield of 19.6%, 41.1%, and 54.0% was achieved at different process condition. In terms of quality, biochar exhibited good heating value (32MJ/kg) than bio-oil (2.47MJ/kg). Bio-oil was also characterised chemically using FTIR and GC-MS method. This work may open new dimension towards development of large-scale MW pyrolysis technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Market Assessment of Biomass Gasification and Combustion Technology for Small- and Medium-Scale Applications

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.; Haase, S.

    2009-07-01

    This report provides a market assessment of gasification and direct combustion technologies that use wood and agricultural resources to generate heat, power, or combined heat and power (CHP) for small- to medium-scale applications. It contains a brief overview of wood and agricultural resources in the U.S.; a description and discussion of gasification and combustion conversion technologies that utilize solid biomass to generate heat, power, and CHP; an assessment of the commercial status of gasification and combustion technologies; a summary of gasification and combustion system economics; a discussion of the market potential for small- to medium-scale gasification and combustion systems; and an inventory of direct combustion system suppliers and gasification technology companies. The report indicates that while direct combustion and close-coupled gasification boiler systems used to generate heat, power, or CHP are commercially available from a number of manufacturers, two-stage gasification systems are largely in development, with a number of technologies currently in demonstration. The report also cites the need for a searchable, comprehensive database of operating combustion and gasification systems that generate heat, power, or CHP built in the U.S., as well as a national assessment of the market potential for the systems.

  5. Heat transfer corrected isothermal model for devolatilization of thermally-thick biomass particles

    DEFF Research Database (Denmark)

    Luo, Hao; Wu, Hao; Lin, Weigang

    Isothermal model used in current computational fluid dynamic (CFD) model neglect the internal heat transfer during biomass devolatilization. This assumption is not reasonable for thermally-thick particles. To solve this issue, a heat transfer corrected isothermal model is introduced. In this model......, two heat transfer corrected coefficients: HT-correction of heat transfer and HR-correction of reaction, are defined to cover the effects of internal heat transfer. A series of single biomass devitalization case have been modeled to validate this model, the results show that devolatilization behaviors...... of both thermally-thick and thermally-thin particles are predicted reasonable by using heat transfer corrected model, while, isothermal model overestimate devolatilization rate and heating rate for thermlly-thick particle.This model probably has better performance than isothermal model when it is coupled...

  6. Characterization and integration of oxidation catalysts at small-scale biomass combustion furnaces

    Directory of Open Access Journals (Sweden)

    Matthes Mirjam

    2017-01-01

    Full Text Available Small-scale biomass combustion is a major part in heat supply from renewable resources. Drawbacks to the environmental background are the pollutant emissions, which are formed as a result of maloperation, suboptimal furnace construction or the biomass fuel composition. The named primary factors can be influenced by several measures, but the achievable emission results are limited. To provide real clean combustion technology with nearly zero pollutant emissions, secondary emission reduction measures are necessary. One of these measures is the application of catalytic flue gas cleaning as integrated or downstream solution. Catalysis is already a state of the art element in many processes and following this, some studies reveal already its potential to reduce CO, VOC as well as particle emissions in small-scale biomass combustion systems. However, a wide application of catalysts in wood combustion units didn’t take place so far, because the challenging process conditions demand a proper integration and highly stable and active catalytic materials. For the achievement of well-functioning combustion systems with catalyst solutions a procedure for application-oriented characterization is presented. Initial investigations with commercially available catalysts have shown that the gas hourly space velocity and the oxygen content have the most significant influence on the conversion rate of carbon monoxide and nitrogen oxide. Two samples with different active phases have been compared, one with solely metal oxides and one with metal oxides and noble metals. The one with noble metals showed as expected a higher activity, but also a higher stability.

  7. Characterization and integration of oxidation catalysts at small-scale biomass combustion furnaces

    Science.gov (United States)

    Matthes, Mirjam; Hartmann, Ingo; Schenk, Joachim; Enke, Dirk

    2017-10-01

    Small-scale biomass combustion is a major part in heat supply from renewable resources. Drawbacks to the environmental background are the pollutant emissions, which are formed as a result of maloperation, suboptimal furnace construction or the biomass fuel composition. The named primary factors can be influenced by several measures, but the achievable emission results are limited. To provide real clean combustion technology with nearly zero pollutant emissions, secondary emission reduction measures are necessary. One of these measures is the application of catalytic flue gas cleaning as integrated or downstream solution. Catalysis is already a state of the art element in many processes and following this, some studies reveal already its potential to reduce CO, VOC as well as particle emissions in small-scale biomass combustion systems. However, a wide application of catalysts in wood combustion units didn't take place so far, because the challenging process conditions demand a proper integration and highly stable and active catalytic materials. For the achievement of well-functioning combustion systems with catalyst solutions a procedure for application-oriented characterization is presented. Initial investigations with commercially available catalysts have shown that the gas hourly space velocity and the oxygen content have the most significant influence on the conversion rate of carbon monoxide and nitrogen oxide. Two samples with different active phases have been compared, one with solely metal oxides and one with metal oxides and noble metals. The one with noble metals showed as expected a higher activity, but also a higher stability.

  8. Biomass Gasification - A synthesis of technical barriers and current research issues for deployment at large scale

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, Stefan [Chalmers Univ. of Technology, Gothenburg (Sweden); Liliedahl, Truls [KTH, Royal Inst. of Technology, Stockholm (Sweden); Marklund, Magnus [Energy Technology Centre, Piteaa (Sweden)

    2013-09-01

    Thermal gasification at large scale for cogeneration of power and heat and/or production of fuels and materials is a main pathway for a sustainable deployment of biomass resources. However, so far no such full scale production exists and biomass gasification projects remain at the pilot or demonstration scale. This report focuses on the key critical technology challenges for the large-scale deployment of the following biomass-based gasification concepts: Direct Fluidized Bed Gasification (FBG), Entrained Flow Gasification (EFG) and indirect Dual Fluidized Bed Gasification (DFBG). The main content in this report is based on responses from a number of experts in biomass gasification obtained from a questionnaire. The survey was composed of a number of more or less specific questions on technical barriers as to the three gasification concepts considered. For formalising the questionnaire, the concept of Technology Readiness Level (TRL 1-9) was used for grading the level of technical maturity of the different sub-processes within the three generic biomass gasification technologies. For direct fluidized bed gasification (FBG) it is mentioned that the technology is already available at commercial scale as air-blown technology and thus that air-blown FBG gasification may be reckoned a mature technology. The remaining technical challenge is the conversion to operation on oxygen with the final goal of producing chemicals or transport fuels. Tar reduction, in particular, and gas cleaning and upgrading in general are by far the most frequently named technical issues considered problematic. Other important aspects are problems that may occur when operating on low-grade fuels - i.e. low-cost fuels. These problems include bed agglomeration/ash sintering as well as alkali fouling. Even the preparation and feeding of these low-grade fuels tend to be problematic and require further development to be used on a commercial scale. Furthermore, efficient char conversion is mentioned by

  9. Application of Heterogeneous Catalysis in Small-Scale Biomass Combustion Systems

    Directory of Open Access Journals (Sweden)

    Christian Thiel

    2012-04-01

    Full Text Available Combustion of solid biomass fuels for heat generation is an important renewable energy resource. The major part among biomass combustion applications is being played by small-scale systems like wood log stoves and small wood pellet burners, which account for 75% of the overall biomass heat production. Despite an environmentally friendly use of renewable energies, incomplete combustion in small-scale systems can lead to the emission of environmental pollutants as well as substances which are hazardous to health. Besides particles of ash and soot, a wide variety of gaseous substances can also be emitted. Among those, polycyclic aromatic hydrocarbons (PAH and several organic volatile and semi-volatile compounds (VOC are present. Heterogeneous catalysis is applied for the reduction of various gaseous compounds as well as soot. Some research has been done to examine the application of catalytic converters in small-scale biomass combustion systems. In addition to catalyst selection with respect to complete oxidation of different organic compounds, parameters such as long-term stability and durability under flue gas conditions are considered for use in biomass combustion furnaces. Possible catalytic procedures have been identified for investigation by literature and market research. Experimental studies with two selected oxidation catalysts based on noble metals have been carried out on a wood log stove with a retrofit system. The measurements have been performed under defined conditions based on practical mode of operation. The measurements have shown that the catalytic flue gas treatment is a promising method to reduce carbon monoxide and volatile organic compounds. Even a reduction of particulate matter was observed, although no filtering effect could be detected. Therefore, the oxidation of soot or soot precursors can be assumed. The selected catalysts differed in their activity, depending on the compound to be oxidized. Examinations showed that

  10. Ethanol Production from Biomass: Large Scale Facility Design Project

    Energy Technology Data Exchange (ETDEWEB)

    Berson, R. Eric [Univ. of Louisville, KY (United States)

    2009-10-29

    High solids processing of biomass slurries provides the following benefits: maximized product concentration in the fermentable sugar stream, reduced water usage, and reduced reactor size. However, high solids processing poses mixing and heat transfer problems above about 15% for pretreated corn stover solids due to their high viscosities. Also, highly viscous slurries require high power consumption in conventional stirred tanks since they must be run at high rotational speeds to maintain proper mixing. An 8 liter scraped surface bio-reactor (SSBR) is employed here that is designed to efficiently handle high solids loadings for enzymatic saccharification of pretreated corn stover (PCS) while maintaining power requirements on the order of low viscous liquids in conventional stirred tanks. Saccharification of biomass exhibit slow reaction rates and incomplete conversion, which may be attributed to enzyme deactivation and loss of activity due to a variety of mechanisms. Enzyme deactivation is classified into two categories here: one, deactivation due to enzyme-substrate interactions and two, deactivation due to all other factors that are grouped together and termed “non-specific” deactivation. A study was conducted to investigate the relative extents of “non-specific” deactivation and deactivation due to “enzyme-substrate interactions” and a model was developed that describes the kinetics of cellulose hydrolysis by considering the observed deactivation effects. Enzyme substrate interactions had a much more significant effect on overall deactivation with a deactivation rate constant about 20X higher than the non-specific deactivation rate constant (0.35 h-1 vs 0.018 h-1). The model is well validated by the experimental data and predicts complete conversion of cellulose within 30 hours in the absence of enzyme substrate interactions.

  11. Woodbased fuels in small-scale regional heating plants

    Energy Technology Data Exchange (ETDEWEB)

    Harkonen, M.

    2012-07-01

    This biomass heating report is compiled as part of the joint Nordic countries EU-Bothnia-Atlantica funded Forest Power project and it explores wood fuels and especially the use of woodchips primarily in the small-scale regional heating plants of Central Ostrobothnia energy cooperatives. The Forest Power project's main coordinator is the Kannus Unit of the Finnish Forest Research Institute (METLA). Other partners in Finland are CENTRIA, the research and development unit of the Central Ostrobothnia University of Applied Sciences, the Kannus Unit of the Central Ostrobothnia Rural Institute, Central Ostrobothnia Forest Owners Association and, of course, the region's energy cooperatives. The ETPC unit at Umeaa University in Sweden also actively participated in this project. This report is based on field measurements conducted during the project at the Kaelviae energy cooperative's woodchip heating plant and is CENTRIA's most visible project outcome. The following individuals participated as researchers in the field measurements: Kari Manninen, project engineer, Anu-Sisko Perttunen, project officer, Martti Harkonen, principal lecturer, Lasse Jansson, director, research and development CENTRIA, Pentti Etelamaki, Central Ostrobothnia Forest Owners Association, Heikki Kykyri and Perttu Suonpera, Kaelviae energy cooperative. The following were project members: Dan Bostrom, Christoffer Boman, Jonathan Fagerstrom, Markus Brostrom and Rainer Backman of Umeaa University's ETPC unit. Martti Harkonen was responsible for the further analysis of the measurement results and report writing. (orig.)

  12. Exergoeconomic analysis of small-scale biomass steam cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Sotomonte, Cesar Adolfo; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba, MG (Brazil)], e-mails: c.rodriguez32@unifei.edu.br, electo@unifei.edu.br; Venturini, Osvaldo Jose; Escobar, Jose Carlos [Universidad Federal de Itajuba, MG (Brazil)], e-mail: osvaldo@unifei.edu.br

    2010-07-01

    The principal objective of this work is to develop a calculation process, based on the second law of thermodynamics, for evaluating the thermoeconomic potential of a small steam cogeneration plant using waste from pulp processing and/or sawmills as fuel. Four different configurations are presented and assessed. The exergetic efficiency of the cycles that use condensing turbines is found to be around 11%, which has almost 3 percent higher efficiency than cycles with back pressure turbines. The thermoeconomic equations used in this paper estimated the production costs varying the fuel price. The main results show that present cost of technologies in a small-scale steam cycle cogeneration do not justify the implementation of more efficient systems for biomass prices less than 100 R$/t. (author)

  13. Integrated Biorefinery for Conversion of Biomass to Ethanol, Synthesis Gas, and Heat

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Gerson [Abengoa Bioenergy, Hugoton, KS (United States)

    2017-06-20

    Goal of the project was to Design, build and operate a commercial scale bioethanol facility that uses sustainable biomass feedstock, drastically reduces greenhouse gas (GHG) emissions while achieving output production, yield and cost targets.

  14. Competing uses of biomass : Assessment and comparison of the performance of bio-based heat, power, fuels and materials

    NARCIS (Netherlands)

    Gerssen-Gondelach, S. J.; Saygin, D.; Wicke, B.; Patel, M. K.; Faaij, A. P. C.

    2014-01-01

    The increasing production of modern bioenergy carriers and biomaterials intensifies the competition for different applications of biomass. To be able to optimize and develop biomass utilization in a sustainable way, this paper first reviews the status and prospects of biomass value chains for heat,

  15. Electrodialytic removal of cadmium from biomass combustion fly ashes in larger scale

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

    The paper presents results from the project: "Electrochemical removal of cadmium from biomass combustion fly ashes in larger scale and evaluation of the possibilities of reusing the treated ashes in concrete".......The paper presents results from the project: "Electrochemical removal of cadmium from biomass combustion fly ashes in larger scale and evaluation of the possibilities of reusing the treated ashes in concrete"....

  16. Topology optimization for nano-scale heat transfer

    DEFF Research Database (Denmark)

    Evgrafov, Anton; Maute, Kurt; Yang, Ronggui

    2009-01-01

    We consider the problem of optimal design of nano-scale heat conducting systems using topology optimization techniques. At such small scales the empirical Fourier's law of heat conduction no longer captures the underlying physical phenomena because the mean-free path of the heat carriers, phonons...

  17. Thermodynamic modelling of an onsite methanation reactor for upgrading producer gas from commercial small scale biomass gasifiers.

    Science.gov (United States)

    Vakalis, S; Malamis, D; Moustakas, K

    2017-06-26

    Small scale biomass gasifiers have the advantage of having higher electrical efficiency in comparison to other conventional small scale energy systems. Nonetheless, a major drawback of small scale biomass gasifiers is the relatively poor quality of the producer gas. In addition, several EU Member States are seeking ways to store the excess energy that is produced from renewables like wind power and hydropower. A recent development is the storage of energy by electrolysis of water and the production of hydrogen in a process that is commonly known as "power-to-gas". The present manuscript proposes an onsite secondary reactor for upgrading producer gas by mixing it with hydrogen in order to initiate methanation reactions. A thermodynamic model has been developed for assessing the potential of the proposed methanation process. The model utilized input parameters from a representative small scale biomass gasifier and molar ratios of hydrogen from 1:0 to 1:4.1. The Villar-Cruise-Smith algorithm was used for minimizing the Gibbs free energy. The model returned the molar fractions of the permanent gases, the heating values and the Wobbe Index. For mixtures of hydrogen and producer gas on a 1:0.9 ratio the increase of the heating value is maximized with an increase of 78%. For ratios higher than 1:3, the Wobbe index increases significantly and surpasses the value of 30 MJ/Nm3. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Co-firing of Coal with Biomass and Waste in Full-scale Suspension-fired Boilers

    DEFF Research Database (Denmark)

    Dam-Johansen, Kim; Jappe Frandsen, Flemming; Jensen, Peter Arendt

    2013-01-01

    The energy policy in Denmark has for many years focused on lowering the net CO2 emission from heat and power production by replacing fossil fuels by renewable resources. This has been done by developing dedicated grate-fired boilers for biomass and waste fuels but also by developing coal...... and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools......-based suspension-fired boilers to accept still higher fractions of biomass or waste material as fuels. This last development has been challenging of many reasons, including pre-treatment of fuels, and solving potential emission and operational problems during the simultaneous development of supercritical steam...

  19. Renewable biomass energy: Understanding regional scale environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Graham, R.L.; Downing, M.

    1993-12-31

    If biomass energy is to become a significant component of the US energy sector, millions of acres of farmland must be converted to energy crops. The environmental implications of this change in land use must be quantitatively evaluated. The land use changes will be largely driven by economic considerations. Farmers will grow energy crops when it is profitable to do so. Thus, models which purport to predict environmental changes induced by energy crop production must take into account those economic features which will influence land use change. In this paper, we present an approach for projecting the probable environmental impacts of growing energy crops at the regional scale. The approach takes into account both economic and environmental factors. We demonstrate the approach by analyzing, at a county-level the probable impact of switchgrass production on erosion, evapotranspiration, nitrate in runoff, and phosphorous fertilizer use in multi-county subregions within the Tennessee Valley Authority (TVA) region. Our results show that the adoption of switchgrass production will have different impacts in each subregion as a result of differences in the initial land use and soil conditions in the subregions. Erosion, evapotranspiration, and nitrate in runoff are projected to decrease in both subregions as switchgrass displaces the current crops. Phosphorous fertilizer applications are likely to increase in one subregion and decrease in the other due to initial differences in the types of conventional crops grown in each subregion. Overall these changes portend an improvement in water quality in the subregions with the increasing adoption of switchgrass.

  20. Successful scaling-up of self-sustained pyrolysis of oil palm biomass under pool-type reactor.

    Science.gov (United States)

    Idris, Juferi; Shirai, Yoshihito; Andou, Yoshito; Mohd Ali, Ahmad Amiruddin; Othman, Mohd Ridzuan; Ibrahim, Izzudin; Yamamoto, Akio; Yasuda, Nobuhiko; Hassan, Mohd Ali

    2016-02-01

    An appropriate technology for waste utilisation, especially for a large amount of abundant pressed-shredded oil palm empty fruit bunch (OFEFB), is important for the oil palm industry. Self-sustained pyrolysis, whereby oil palm biomass was combusted by itself to provide the heat for pyrolysis without an electrical heater, is more preferable owing to its simplicity, ease of operation and low energy requirement. In this study, biochar production under self-sustained pyrolysis of oil palm biomass in the form of oil palm empty fruit bunch was tested in a 3-t large-scale pool-type reactor. During the pyrolysis process, the biomass was loaded layer by layer when the smoke appeared on the top, to minimise the entrance of oxygen. This method had significantly increased the yield of biochar. In our previous report, we have tested on a 30-kg pilot-scale capacity under self-sustained pyrolysis and found that the higher heating value (HHV) obtained was 22.6-24.7 MJ kg(-1) with a 23.5%-25.0% yield. In this scaled-up study, a 3-t large-scale procedure produced HHV of 22.0-24.3 MJ kg(-1) with a 30%-34% yield based on a wet-weight basis. The maximum self-sustained pyrolysis temperature for the large-scale procedure can reach between 600 °C and 700 °C. We concluded that large-scale biochar production under self-sustained pyrolysis was successfully conducted owing to the comparable biochar produced, compared with medium-scale and other studies with an electrical heating element, making it an appropriate technology for waste utilisation, particularly for the oil palm industry. © The Author(s) 2015.

  1. Solar-assisted biomass-district heating: projects in Austria and operational data; Solarunterstuetzte Biomasse-Fernwaermeversorgung: Projekte in Oesterreich und Betriebsdaten

    Energy Technology Data Exchange (ETDEWEB)

    Faninger, G. [Institut fuer Interdisziplinaere Forschung und Fortbildung der Universitaeten Klagenfurt, Innsbruck und Wien (IFF), Klagenfurt (Austria)

    1998-12-31

    In recent years small-volume biomass district heating systems (district heat grids) have attracted increasing interest in Austria. By the end of 1997 some 359 biomass-district heating systems with an overall capacity of approximately 483 MW were in operation. If a biomass-district heating plant and a solar plant are combined the solar plant can supply most of the heat required outside the heating season. At present Austria runs 12 solar-assisted biomass-district heating grids with collector areas between 225 square metres and 1,250 square metres. In order to run these biomass-district heating systems in an economically and technically efficient way it is necessary to assure high quality in terms of planning, construction and operation. A list of criteria is set up on the basis of first operational data in order to evaluate energy efficiency and economic performance. These criteria should be applied in order to ensure that energy, environment and economy are equally considered in the planning and construction of solar-assisted biomass-district heating plants. They should also be helpful for the approval procedures of projects. (orig.) [Deutsch] Kleinraeumige Biomasse-Fernwaermeanlagen (Nahwaermenetze) fanden in den letzten Jahren zunehmendes Interesse in Oesterreich. So waren Ende 1997 insgesamt 359 Biomasse-Fernwaermeanlagen mit einer installierten Gesamtleistung von etwa 483 MW in Betrieb. Die Kombination einer Biomasse-Fernwaermeanlage mit einer Solaranlage bringt den Vorteil, dass die Waermebereitstellung ausserhalb der Heizsaison zu einem hohen Anteil ueber die Solaranlage vorgenommen werden kann. Derzeit werden in Oesterreich 12 solarunterstuetzte Biomasse-Nahwaermenetze mit Kollektorflaechen von 225 m{sup 2} bis 1.250 m{sup 2} betrieben. Um einen moeglichst effizienten und damit auch wirtschaftlichen Betrieb von solarunterstuetzten Biomasse-Fernwaermeanlagen zu gewaehrleisten, werden hohe Anforderungen an Planung, Ausfuehrung und Betrieb gestellt. Auf der

  2. Drying and heat decomposition of biomass during the production of biochar

    Science.gov (United States)

    Lyubov, V. K.; Popova, E. I.

    2017-11-01

    The process of wood torrefaction provides an opportunity to combine properties of biofuel and steam coal. Different degrees of biofuel heat treating leads to varied outcomes and varied biochar heating value. Therefore, the torrefaction process requires optimal operation that ensures the highest heating value of biochar with the lowest energy loss. In this paper we present the experimental results of drying cycle and thermal decomposition of particles of spruce stem wood and hydrolytic lignin in argon under various temperature conditions and basic material humidity as well as changes in the morphological structure of the biomass and its grain size composition during the torrefaction.

  3. Bench scale steam explosion pretreatment of acid impregnated elephant grass biomass and its impacts on biomass composition, structure and hydrolysis

    NARCIS (Netherlands)

    Kataria, Rashmi; Mol, Annemerel; Schulten, Els; Happel, Anton; Mussatto, Solange I.

    2017-01-01

    In the present study, an acid mediated steam explosion process was evaluated for pretreatment of elephant grass biomass in a bench scale reactor. Different combinations of H2SO4 concentration, reaction time and temperature (leading to different values of combined severity factor - CSF) were used for

  4. Analysis of Competitiveness and Support Instruments for Heat and Electricity Production from Wood Biomass in Latvia

    Science.gov (United States)

    Klavs, G.; Kudrenickis, I.; Kundzina, A.

    2012-01-01

    Utilisation of renewable energy sources is one of the key factors in a search for efficient ways of reducing the emissions of greenhouse gases and improving the energy supply security. So far, the district heating supply in Latvia has been based on natural gas, with the wood fuel playing a minor role; the same is true for decentralised combined heat-power (CHP) production. The paper describes a method for evaluation of the economic feasibility of heat and electricity production from wood biomass under the competition between different fuel types and taking into account the electricity market. For the simulation, a cost estimation model is applied. The results demonstrate that wood biomass can successfully be utilised for competitive heat production by boiler houses, while for electricity production by CHP utilities it cannot compete on the market (even despite the low prices on wood biomass fuel) unless particular financial support instruments are applied. The authors evaluate the necessary support level and the impact of two main support instruments - the investment subsidies and the feed-in tariff - on the economic viability of wood-fuelled CHP plants, and show that the feed-in tariff could be considered as an instrument strongly affecting the competitiveness of such type CHP. Regarding the feed-in tariff determination, a compromise should be found between the economy-dictated requirement to develop CHP projects concerning capacities above 5 MWel - on the one hand, and the relatively small heat loads in many Latvian towns - on the other.

  5. Analysis of a furnace for heat generation using polydisperse biomass

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Edney Alves; Silva, Juarez de Sousa e; Silva, Jadir Nogueira da; Oliveira Filho, Delly [Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola; Donzeles, Sergio Mauricio Lopes [Empresa de Pesquisa Agropecuaria de Minas Gerais (EPAMIG), Vicosa, MG (Brazil)

    2008-07-01

    In many agro-industrial activities, the processing of raw material generates a substantial amount of fine materials. Examples include the production of soluble coffee, processing of rice, and wood processing, among others. In many regions, these by-products keep piling up on the courtyard of companies or become an environmental problem for land dumps. However, detailed tests of these byproducts indicate that they are excellent sources of energy. With this in mind, a furnace was developed to generate clean and hot air, using the alimentation system for pneumatic transport. Wood sawdust was used as fuel for analysis. The obtained results were considered satisfactory, proven by the small heat losses, primarily by the non-burned carbon monoxide (less than 0.2%) and the cooling of the furnace (less than 2.5%) whereas the losses by the exhaust gases were a little more than 23%. The thermal efficiency of the furnace was considered high when compared to others with an indirect heating system, obtaining an average value of 73%. The developed furnace, beyond being efficient, allows the use of the waste from the wood industry, which is important in the reduction of environmental impacts and minimizing production costs associated with the acquisition of conventional energy. (author)

  6. Use of biomass for clean and efficient production of heat and power. Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Glarborg, P.; Lans, R. van der; Frandsen, J.B.F.; Johnsson, J.E.; Jensen, A.; Kiil, S.; Dam-Johansen, K.

    2001-03-01

    The present EFP98 project is the second phase of a long-term, strategic research project, the aim of which is to facilitate the use of significant amounts of biomass in the production of power and heat. The project deals with combustion and emission issues related to the use of biomass, specifically combustion of straw on a grate and wet flue gas desulphurization. A mathematical model for combustion of straw on a grate is developed as a tool to improve the understanding of this process. The model includes heat transfer to and in the bed as well as pyrolysis and char oxidation. To verify the model and to obtain a better understanding of fixed-bed straw combustion, a number of bench-scale laboratory experiments have been conducted at TNO in Holland. Predicted combustion rates and bed temperatures were in fairly good agreement with experimental fixed-bed data. A parameter analysis has identified the sensitivity of modeling predictions towards important parameters in the model. Measuring programs on straw firing have been conducted at Enstedvaerket and Masnedoe. Measuring results include gas temperature and gas composition (O{sub 2}, CO{sub 2}, CO. SO{sub 2}, NO) from different positions in the boiler. Data from Masnedoe include also results from co-firing of straw with other biomass fuels (25-35%). The results indicate that co-firing in the quantities does not significantly affect emissions. Nitrogen oxides emissions from Masnedoevaerket were found to be significantly higher than those of Ensted. The work on wet flue gas desulphurization on aimed to provide the information necessary to optimize and further develop the process. The main focus was fuel and sorbent flexibility, use of the waste product from the semi-dry FGD process as a sorbent in wet FGD, and ways of optimizing the Wet FGD process with respect to a high degree of desulphurization, a low content of residual limestone in the gypsum and a continuous steady state operation of the FGD plant. Laboratory

  7. Sustainability assessment of heat supply from biomass; Nachhaltigkeitsbewertung der Waermeversorgung aus Biomasse

    Energy Technology Data Exchange (ETDEWEB)

    Zech, Daniel; Jenssen, Till; Eltrop, Ludger [Stuttgart Univ. (Germany). Inst. fuer Energiewirtschaft und Rationelle Energieanwendung (IER); Wassermann, Sandra [Stuttgart Univ. (Germany). Interdisziplinaerer Forschungsschwerpunkt Risiko und Nachhaltige Technikentwicklung am Zentrum fuer Kultur und Technikforschung

    2010-07-01

    The authors present two approaches for integrated sustainability assessment of technologies, i.e. multicriteria decision analysis (MCDA) and the social cost of heat supply. Both approaches were developed by an interdisciplinary scientist team in the context of a BMFB-funded project (''Energie nachhaltig konsumieren - nachhaltige Energie konsumieren'') and were applied to the example of a modernized single-family home consuming 82 kWh per square metre per annum.

  8. Initial Market Assessment for Small-Scale Biomass-Based CHP

    Energy Technology Data Exchange (ETDEWEB)

    Brown, E.; Mann, M.

    2008-01-01

    The purpose of this report is to reexamine the energy generation market opportunities for biomass CHP applications smaller than 20 MW. This paper provides an overview of the benefits of and challenges for biomass CHP in terms of policy, including a discussion of the drivers behind, and constraints on, the biomass CHP market. The report provides a summary discussion of the available biomass supply types and technologies that could be used to feed the market. Two primary markets are outlined--rural/agricultural and urban--for small-scale biomass CHP, and illustrate the primary intersections of supply and demand for those markets. The paper concludes by summarizing the potential markets and suggests next steps for identifying and utilizing small-scale biomass.

  9. Retrofitting of municipal coal fired heating plant with integrated biomass gasification gas turbine based cogeneration block

    Energy Technology Data Exchange (ETDEWEB)

    Kalina, Jacek [Silesian University of Technology, Institute of Thermal Technologies, Knarskiego 22, 44-100 Gliwice (Poland)

    2010-05-15

    Biomass has a significant potential for reduction of both CO{sub 2} emission and consumption of fossil fuels in energy production sector. On the other hand the successful implementation of biomass into regional energy systems is strongly influenced by many political, economic and technical factors. The best effects can be obtained if a proper choice of biomass plant technology has been made. The objective of this work is the analysis and discussion of technical and economic benefits of retrofitting an existing coal-fired municipal heating plant with integrated biomass gasification cogeneration block. The project leads to both local and global reduction of emission and fossil fuels consumption. An investment decision is however dependent on economic profitability, which is also examined in this work. Four design alternatives were proposed and modeled with using Cycle-Tempo simulation software. An annual mass and energy balance of the plant was calculated and economic analysis was performed. The results indicate a great energy and emission savings potential. An effective financial support, that results from local renewable energy promotion policy, can make an economic performance of the project attractive. The best technical solution for the retrofitting the analyzed heating plant was the combined cycle integrated with gasification of biomass with steam. (author)

  10. Catalytic combustion of gasified biomass for electricity and heat production

    Energy Technology Data Exchange (ETDEWEB)

    Jaeraas, S.; Johansson, Magnus [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    1996-01-01

    High temperature catalytic combustion of gasified biomass for gas turbine applications has been studied, with emphasis on NH{sub 3} conversion and ignition characteristics of the main fuel components CO, H{sub 2} and CH{sub 4}. Three sets of catalysts have been evaluated: Alumina supported transition metal oxides, Unsupported perovskites, and Complex oxide materials such as hexaaluminate supported perovskites and BaMn-hexaaluminates. The three fuel components CO, H{sub 2} and CH{sub 4} ignited in different order, depending on the catalyst material. To design a multi-monolithic catalytic combustion chamber, it will be important to examine at which temperature and in which order the fuel mixture ignites. The analysis of NH{sub 3} conversion to NO{sub x} and N{sub 2} showed that the alumina supported transition metal oxides gave conversion between 21% and 86% to N{sub 2}, where the best result was for NiO catalyst. However, at higher temperatures it is likely that these catalysts sinter and that NO{sub x} formation increases. Pt catalyst showed high conversion of NH{sub 3} to NO{sub x}, <20% to N{sub 2}. Complex oxides showed showed the most promising result with conversion 20 - 80% to N{sub 2}, depending on inlet temperature and catalyst. For BaMn-hexaaluminate 75 - 78% of NH{sub 3} was converted to N{sub 2} between 600 and 750 deg C. For LaNiO{sub 3}/La-hexaaluminate 90% of the NH{sub 3} was converted between 700 and 750 deg C and no NO formed. In addition, the formation of HCN and N{sub 2}O was analysed for some catalysts. The analyses showed that 5 - 10 ppm of N{sub 2}O and HCN was formed at 850 - 950 deg C. The results indicate that it would be possible to design a segmented catalytic combustion chamber, with a first segment working at a temperature window where all NH{sub 3} is converted to N{sub 2} and only 0 - 20% of the fuel components are converted. 34 refs

  11. Assessment of integration of different biomass gasification alternatives in a district-heating system

    Energy Technology Data Exchange (ETDEWEB)

    Fahlen, E.; Ahlgren, E.O. [Department of Energy and Environment, Energy Systems Technology, Division of Energy Technology, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2009-12-15

    With increasingly stringent CO{sub 2} emission reduction targets, incentives for efficient use of limited biomass resources increase. Technologies for gasification of biomass may then play a key role given their potential for high electrical efficiency and multiple outputs; not only electricity but also bio transport fuels and district heat. The aim of this study is to assess the economic consequences and the potential for CO{sub 2} reduction of integration of a biomass gasification plant into a district-heating (DH) system. The study focuses on co-location with an existing natural gas combined cycle heat and power plant in the municipal DH system of Goeteborg, Sweden. The analysis is carried out using a systems modelling approach. The so-called MARTES model is used. MARTES is a simulating, DH systems supply model with a detailed time slice division. The economic robustness of different solutions is investigated by using different sets of parameters for electricity price, fuel prices and policy tools. In this study, it is assumed that not only tradable green certificates for electricity but also tradable green certificates for transport fuels exist. The economic results show strong dependence on the technical solutions and scenario assumptions but in most cases a stand-alone SNG-polygeneration plant with district-heat delivery is the cost-optimal solution. Its profitability is strongly dependent on policy tools and the price relation between biomass and fossil fuels. Finally, the results show that operation of the biomass gasification plants reduces the (DH) system's net emissions of CO{sub 2}. (author)

  12. Conventional and microwave-assisted pyrolysis of biomass under different heating rates

    OpenAIRE

    Wu, C; Budarin, VL; Gronnow, MJ; De Bruyn, M; Onwudili, JA; Clark, JH; Williams, PT

    2014-01-01

    Biomass was subjected to conventional and microwave pyrolysis, to determine the influence of each process on the yield and composition of the derived gas, oil and char products. The influence of pyrolysis temperature and heating rate for the conventional pyrolysis and the microwave power was investigated. Two major stages of gas release were observed during biomass pyrolysis, the first being CO/CO and the second one CH/H. This two-stage gas release was much more obvious for the conventional p...

  13. Biomass district heating in the Tug Hill, NY: Feasibility and regional economic impacts

    Science.gov (United States)

    Hendricks, Aaron

    Biomass district heating (BDH) has the potential to stimulate rural economies in the Tug Hill region of New York State by establishing a local industry and providing lower cost heat compared to the local alternative, #2 fuel oil. However, the competitiveness and economic impact of BDH networks in rural villages is largely unknown. This study proposes a methodology to provide initial assessments of the feasibility of BDH in rural communities. BDH would deliver heat below the cost of the local alternative in eight of the ten study villages examined. Capital costs comprised over 80% of the project costs, illuminating the importance of reaching a sufficient heat density; however, specific building heat was a stronger determinant of a village's feasibility. An input-output analysis determined that BDH would generate $18.6 million in output and create 143 jobs throughout the three county region, a significant impact if concentrated around the study villages.

  14. Forest biomass supply for bioenergy in the southeast: Evaluating assessment scale

    Science.gov (United States)

    Christopher S. Galik; Robert C. Abt

    2012-01-01

    This study evaluates the potential impacts of expanded forest biomass use in the Southeast from present year through 2036, focusing on the forest supply, industrial, and GHG emissions implications of maximizing biomass co-firing with coal. We model demand scenarios at the state, subregional, and regional levels, and assess the influence of study scale on the observed...

  15. An economic assessment of the use of short-rotation coppice woody biomass to heat greenhouses in southern Canada

    Energy Technology Data Exchange (ETDEWEB)

    McKenney, Daniel W.; Yemshanov, Denys; Fraleigh, Saul; Allen, Darren; Preto, Fernando [Natural Resources (Canada)

    2011-01-15

    This study explores the economic feasibility of fossil fuel substitution with biomass from short-rotation willow plantations as an option for greenhouse heating in southern Ontario, Canada. We assess the net displacement value of fossil fuel biomass combustion systems with an integrated purpose-grown biomass production enterprise. Key project parameters include greenhouse size, heating requirements, boiler capital costs and biomass establishment and management costs. Several metrics have been used to examine feasibility including net present value, internal rate of return, payback period, and the minimum or break-even prices for natural gas and heating oil for which the biomass substitution operations become financially attractive. Depending on certain key assumptions, internal rates of return ranged from 11-14% for displacing heating oil to 0-4% for displacing natural gas with woody biomass. The biomass heating projects have payback periods of 10 to >22 years for substituting heating oil and 18 to >22 years for replacing a natural gas. Sensitivity analyses indicate that fossil fuel price and efficiency of the boiler heating system are critical elements in the analyses and research on methods to improve growth and yield and reduce silviculture costs could have a large beneficial impact on the feasibility of this type of bioenergy enterprise. (author)

  16. Experimental investigation of small-scale gasification of woody biomass

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, Maria

    2002-05-01

    A small-scale stratified down draft gasifier has been built and operated under stable conditions using wood pellets as fuel and air as gasification agent. The problems observed during the preliminary experiments have been described and explained; they are mainly related to the stability of the process. The stable operation of the gasifier has been characterised by the gas composition and the product gas tar and particle content. The biomass feeding rate has varied between 4,5 and 6,5 kg/h. The CO content of the product gas (23-26 % vol.) is higher than in similar gasifiers and the H{sub 2} content has been found to vary between 14 and 16 % vol. The tar content in the product gas (Ca. 3 g/Nm{sup 3}) is rather high compared with similar gasifiers. The temperature profile, together with other relevant parameters like the air-excess ratio, the air to fuel ratio and gas to fuel ratio have been calculated. The experiments show that the air excess ratio is rather constant, varying between 0,25 and 0,3. Experiments have been conducted with a gas engine using mixtures of CH{sub 4}, CO, H{sub 2}, CO{sub 2} and N{sub 2} as a fuel. NO{sub x} and CO emissions are analysed. The char gasification process has been studied in detail by means of Thermogravimetric Analysis. The study comprises the chemical kinetics of the gasification reactions of wood char in CO{sub 2} and H{sub 2}O, including the inhibition effect of CO and H{sub 2}. A kinetic model based on Langmuir-Hinshelwood kinetics has been found which relates the mass loss rate to the temperature, gas composition and degree of conversion for each reaction. The ratio CO/CO{sub 2} has been found to be a relevant parameter for reactivity. The gasification experiments in mixtures of CO{sub 2} and H{sub 2}O give reasons to believe that the rate of desorption for the complex C(O) varies depending on the gas mixture surrounding the char. It has been found that if the experimental data are obtained from separate H{sub 2}O/N{sub 2

  17. Study on the application of combined cooling, heating and power system with biomass energy in China

    Science.gov (United States)

    Guan, Haibin; Sun, Rongfeng; Zhang, Weijie; Fan, Xiaoxu; Jiang, Jianguo; Zhao, Baofeng

    2017-08-01

    CCHP (Combined Cooling Heating and Power) system is highly evaluated and developed rapidly around the world possessing better performance than traditional energy systems because of the cascade utilization of energy. Biomass is one of the renewable energy resources that is abundant and has been widely used in China for a long time. In this paper the principle and development of biomass gasification system and CCHP is clarified, the feasibility of combining the two systems together is analyzed from theoretical and technical points of view, and the active significance is also indicated. In conclusion, it is feasible to develop CCHP with Biomass Energy in an agricultural country such as China, which can flourish in the future.

  18. Microbial biomass and activity in soils with different moisture content heated at high temperatures

    Science.gov (United States)

    Barreiro, Ana; Lombao, Alba; Martin, Angela; Cancelo-González, Javier; Carballas, Tarsy; Díaz-Raviña, Montserrat

    2015-04-01

    It is well known that soil properties determining the thermal transmissivity (moisture, texture, organic matter, etc.) and the duration and temperatures reached during soil heating are key factors driving the fire-induced changes in soil microbial communities. However, despite its interest, the information about this topic is scarce. The aim of the present study is to analyze, under laboratory conditions, the impact of the thermal shock (infrared lamps reaching temperatures of 100 °C, 200 °C and 400 °C) on microbial communities of three acid soils under different moisture level (0 %, 25 % and 50 % per soil volume). Soil temperature was measured with thermocouples and the impact of soil heating was evaluated by means of the analysis of the temperature-time curves calculating the maximum temperature reached (Tmax) and the degree-hours (GH) as an estimation of the amount of heat supplied to the samples (fire severity). The bacterial growth (leucine incorporation) and the total microbial biomass (PLFA) were measured immediately after the heating and one month after the incubation of reinoculated soils. The results showed clearly the importance of moisture level in the transmission of heat through the soil and hence in the further direct impact of high temperatures on microorganisms living in soil. In general, the values of microbial parameters analyzed were low, particularly immediately after soil heating at higher temperatures; the bacterial activity measurements (leucine incorporation technique) being more sensitive to detect the thermal shock showed than total biomass measurements (PLFA). After 1 month incubation, soil microbial communities tend to recover due to the proliferation of surviving population using as substrate the dead microorganisms (soil sterilization). Thus, time elapsed after the heating was found to be decisive when examining the relationships between the microbial properties and the soil heating parameters (GH, Tmax). Analysis of results also

  19. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    Directory of Open Access Journals (Sweden)

    Sensho Honma

    2014-01-01

    Full Text Available The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds.

  20. Fossil fuel and biomass burning effect on climate - Heating or cooling?

    Science.gov (United States)

    Kaufman, Yoram J.; Fraser, Robert S.; Mahoney, Robert L.

    1991-01-01

    The basic theory of the effect of pollution on cloud microphysics and its global implications is applied to compare the relative effect of a small increase in the consumption rate of oil, coal, or biomass burning on cooling and heating of the atmosphere. The characteristics of and evidence for the SO2 induced cooling effect are reviewed. This perturbation analysis approach permits linearization, therefore simplifying the analysis and reducing the number of uncertain parameters. For biomass burning the analysis is restricted to burning associated with deforestation. Predictions of the effect of an increase in oil or coal burning show that within the present conditions the cooling effect from oil and coal burning may range from 0.4 to 8 times the heating effect.

  1. Effect of catalytic pyrolysis conditions using pulse current heating method on pyrolysis products of wood biomass.

    Science.gov (United States)

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800 °C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800 °C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds.

  2. Process modelling of biomass conversion to biofuels with combined heat and power.

    Science.gov (United States)

    Sharma, Abhishek; Shinde, Yogesh; Pareek, Vishnu; Zhang, Dongke

    2015-12-01

    A process model has been developed to study the pyrolysis of biomass to produce biofuel with heat and power generation. The gaseous and solid products were used to generate heat and electrical power, whereas the bio-oil was stored and supplied for other applications. The overall efficiency of the base case model was estimated for conversion of biomass into useable forms of bio-energy. It was found that the proposed design is not only significantly efficient but also potentially suitable for distributed operation of pyrolysis plants having centralised post processing facilities for production of other biofuels and chemicals. It was further determined that the bio-oil quality improved using a multi-stage condensation system. However, the recycling of flue gases coming from combustor instead of non-condensable gases in the pyrolyzer led to increase in the overall efficiency of the process with degradation of bio-oil quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    Science.gov (United States)

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

  4. Design of Biomass Gasification and Combined Heat and Power Plant Based on Laboratory Experiments

    Science.gov (United States)

    Haydary, Juma; Jelemenský, Ľudovít

    Three types of wooden biomass were characterized by calorimetric measurements, proximate and elemental analysis, thermogravimetry, kinetics of thermal decomposition and gas composition. Using the Aspen steady state simulation, a plant with the processing capacity of 18 ton/h of biomass was modelled based on the experimental data obtained under laboratory conditions. The gasification process has been modelled in two steps. The first step of the model describes the thermal decomposition of the biomass based on a kinetic model and in the second step, the equilibrium composition of syngas is calculated by the Gibbs free energy of the expected components. The computer model of the plant besides the reactor model includes also a simulation of other plant facilities such as: feed drying employing the energy from the process, ash and tar separation, gas-steam cycle, and hot water production heat exchangers. The effect of the steam to air ratio on the conversion, syngas composition, and reactor temperature was analyzed. Employment of oxygen and air for partial combustion was compared. The designed computer model using all Aspen simulation facilities can be applied to study different aspects of biomass gasification in a Combined Heat and Power plant.

  5. Modeling heat efficiency, flow and scale-up in the corotating disc scraped surface heat exchanger

    DEFF Research Database (Denmark)

    Friis, Alan; Szabo, Peter; Karlson, Torben

    2002-01-01

    A comparison of two different scale corotating disc scraped surface heat exchangers (CDHE) was performed experimentally. The findings were compared to predictions from a finite element model. We find that the model predicts well the flow pattern of the two CDHE's investigated. The heat transfer...... performance predicted by the model agrees well with experimental observations for the laboratory scale CDHE whereas the overall heat transfer in the scaled-up version was not in equally good agreement. The lack of the model to predict the heat transfer performance in scale-up leads us to identify the key...

  6. Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gangwal, Santosh K. [Southern Research Institute, Durham, NC (United States); McCabe, Kevin [Southern Research Institute, Durham, NC (United States)

    2015-04-30

    The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifier (TRIGTM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.

  7. Thermal power generation projects ``Large Scale Solar Heating``; EU-Thermie-Projekte ``Large Scale Solar Heating``

    Energy Technology Data Exchange (ETDEWEB)

    Kuebler, R.; Fisch, M.N. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany)

    1998-12-31

    The aim of this project is the preparation of the ``Large-Scale Solar Heating`` programme for an Europe-wide development of subject technology. The following demonstration programme was judged well by the experts but was not immediately (1996) accepted for financial subsidies. In November 1997 the EU-commission provided 1,5 million ECU which allowed the realisation of an updated project proposal. By mid 1997 a small project was approved, that had been requested under the lead of Chalmes Industriteteknik (CIT) in Sweden and is mainly carried out for the transfer of technology. (orig.) [Deutsch] Ziel dieses Vorhabens ist die Vorbereitung eines Schwerpunktprogramms `Large Scale Solar Heating`, mit dem die Technologie europaweit weiterentwickelt werden sollte. Das daraus entwickelte Demonstrationsprogramm wurde von den Gutachtern positiv bewertet, konnte jedoch nicht auf Anhieb (1996) in die Foerderung aufgenommen werden. Im November 1997 wurden von der EU-Kommission dann kurzfristig noch 1,5 Mio ECU an Foerderung bewilligt, mit denen ein aktualisierter Projektvorschlag realisiert werden kann. Bereits Mitte 1997 wurde ein kleineres Vorhaben bewilligt, das unter Federfuehrung von Chalmers Industriteknik (CIT) in Schweden beantragt worden war und das vor allem dem Technologietransfer dient. (orig.)

  8. Insight on invasions and resilience derived from spatiotemporal discontinuities of biomass at local and regional scales

    Science.gov (United States)

    Angeler, David G.; Allen, Criag R.; Johnson, Richard K.

    2012-01-01

    Understanding the social and ecological consequences of species invasions is complicated by nonlinearities in processes, and differences in process and structure as scale is changed. Here we use discontinuity analyses to investigate nonlinear patterns in the distribution of biomass of an invasive nuisance species that could indicate scale-specific organization. We analyze biomass patterns in the flagellate Gonyostomum semen (Raphidophyta) in 75 boreal lakes during an 11-year period (1997-2007). With simulations using a unimodal null model and cluster analysis, we identified regional groupings of lakes based on their biomass patterns. We evaluated the variability of membership of individual lakes in regional biomass groups. Temporal trends in local and regional discontinuity patterns were analyzed using regressions and correlations with environmental variables that characterize nutrient conditions, acidity status, temperature variability, and water clarity. Regionally, there was a significant increase in the number of biomass groups over time, indicative of an increased number of scales at which algal biomass organizes across lakes. This increased complexity correlated with the invasion history of G. semen and broad-scale environmental change (recovery from acidification). Locally, no consistent patterns of lake membership to regional biomass groups were observed, and correlations with environmental variables were lake specific. The increased complexity of regional biomass patterns suggests that processes that act within or between scales reinforce the presence of G. semen and its potential to develop high-biomass blooms in boreal lakes. Emergent regional patterns combined with locally stochastic dynamics suggest a bleak future for managing G. semen, and more generally why invasive species can be ecologically successful.

  9. Multiple Scales Analysis of a Thermoacoustic Heat Pump

    Science.gov (United States)

    Miller, Michael; Mandre, Shreyas

    2012-11-01

    Thermoacoustics utilizes the temperature and density oscillations inherent to acoustic vibrations coupled with heat conduction near a wall to produce heat transfer from sound (or sound from a heat source). In the heat pump setup, thermal energy is transferred to the wall from an element of gas during compression and taken from the wall during rarefaction. In thermoacoustic phenomena, acoustic oscillations occur on a very short time scale while heat transfer occurs over many acoustic cycles. Therefore, multiple scales analysis is well suited to describe the physics. We present a multiple scales analysis for a narrow two-dimensional channel between two thin, non-stationary plates resulting in an integral equation for the temperature distribution along the channel as a function of the long time scale. We solved this equation numerically to find a steady state solution for a given set of parameters.

  10. Laboratory-scale method for enzymatic saccharification of lignocellulosic biomass at high-solids loadings

    Directory of Open Access Journals (Sweden)

    Dibble Clare J

    2009-11-01

    Full Text Available Abstract Background Screening new lignocellulosic biomass pretreatments and advanced enzyme systems at process relevant conditions is a key factor in the development of economically viable lignocellulosic ethanol. Shake flasks, the reaction vessel commonly used for screening enzymatic saccharifications of cellulosic biomass, do not provide adequate mixing at high-solids concentrations when shaking is not supplemented with hand mixing. Results We identified roller bottle reactors (RBRs as laboratory-scale reaction vessels that can provide adequate mixing for enzymatic saccharifications at high-solids biomass loadings without any additional hand mixing. Using the RBRs, we developed a method for screening both pretreated biomass and enzyme systems at process-relevant conditions. RBRs were shown to be scalable between 125 mL and 2 L. Results from enzymatic saccharifications of five biomass pretreatments of different severities and two enzyme preparations suggest that this system will work well for a variety of biomass substrates and enzyme systems. A study of intermittent mixing regimes suggests that mass transfer limitations of enzymatic saccharifications at high-solids loadings are significant but can be mitigated with a relatively low amount of mixing input. Conclusion Effective initial mixing to promote good enzyme distribution and continued, but not necessarily continuous, mixing is necessary in order to facilitate high biomass conversion rates. The simplicity and robustness of the bench-scale RBR system, combined with its ability to accommodate numerous reaction vessels, will be useful in screening new biomass pretreatments and advanced enzyme systems at high-solids loadings.

  11. Species richness and allometric scaling jointly determine biomass in model aquatic food webs.

    Science.gov (United States)

    Long, Zachary T; Steiner, Christopher F; Krumins, Jennifer Adams; Morin, Peter J

    2006-07-01

    1. Allometric theory makes specific predictions about how density, and consequently biomass, scale with organism size within trophic levels, across trophic levels and across food webs. 2. Diversity-yield relationships suggest that more diverse food webs can sometimes support more biomass through mechanisms involving niche complementarity or selection effects that are sometimes attributed to organism size. 3. We combine the above two approaches and show that, generally, density and biomass scale with organism size within and between trophic levels as predicted by allometric theory. Further, food webs converged in total biomass despite persistent differences in the composition and size of the organisms among food webs; species richness explained deviations from the constant yield of biomass expected from size-abundance relationships. 4. Our results suggest that organism size plays only a transient role in controlling community biomass because population increases or decreases lead to rapid convergence in biomass. Species richness affects community biomass independently by effectively increasing the mass of organisms that can be supported in a given productivity regime.

  12. Energy conversion of biomass with supercritical and subcritical water using large-scale plants.

    Science.gov (United States)

    Okajima, Idzumi; Sako, Takeshi

    2014-01-01

    Exploiting unused or waste biomass as an alternative fuel is currently receiving much attention because of the potential reductions in CO2 emissions and the lower cost in comparison to expensive fossil fuels. If we are to use biomass domestically or industrially, we must be able to convert biomass to high-quality and easy-to-use liquid, gas, or solid fuels that have high-calorific values, low moisture and ash contents, uniform composition, and suitable for stored over long periods. In biomass treatment, hot and high-pressure water including supercritical and subcritical water is an excellent solvent, as it is clean and safe and its action on biomass can be optimized by varying the temperature and pressure. In this article, the conversion of waste biomass to fuel using hot and high-pressure water is reviewed, and the following examples are presented: the production of large amounts of hydrogen from waste biomass, the production of cheap bioethanol from non-food raw materials, and the production of composite powder fuel from refractory waste biomass in the rubble from the Great East Japan Earthquake. Several promising techniques for the conversion of biomass have been demonstrated in large-scale plants and commercial deployment is expected in the near future. Copyright © 2013. Published by Elsevier B.V.

  13. Optimization of Microwave-Based Heating of Cellulosic Biomass Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Yu-Ting Yeh

    2013-08-01

    Full Text Available This study discusses the application of microwave-based heating for the pretreatment of biomass material, with Pennisetum purpureum selected for pretreatment. The Taguchi method was used to plan optimization experiments for the pretreatment parameter levels, and to measure the dynamic responses. With a low number of experiments, this study analyzed and determined a parameter combination in which Pennisetum purpureum can be rapidly heated to 190 °C. The experimental results suggested that the optimal parameter combination is: vessel capacity of 150 mL (level 2, heating power of 0.5 kW (level 1, and mass of Pennisetum purpureum of 5 g (level 1. The mass of Pennisetum purpureum is a key factor affecting system performance. An eight-order ARX model (Auto-Regressive eXogeneous was representative of the actual system performance, and the fit was 99.13%. The results proved that microwave-based heating, with the assistance of the Taguchi method for pretreatment of the biomass material, can reduce the parameter combination variations.

  14. Scaling relationships of twig biomass allocation in Pinus hwangshanensis along an altitudinal gradient.

    Science.gov (United States)

    Li, Man; Zheng, Yuan; Fan, RuiRui; Zhong, QuanLin; Cheng, DongLiang

    2017-01-01

    Understanding the response of biomass allocation in twigs (the terminal branches of current-year shoots) to environmental change is crucial for elucidating forest ecosystem carbon storage, carbon cycling, and plant life history strategies under a changing climate. On the basis of interspecies investigations of broad-leaved plants, previous studies have demonstrated that plants respond to environmental factors by allocating biomass in an allometric manner between support tissues (i.e., stems) and the leaf biomass of twigs, where the scaling exponent (i.e., slope of a log-log linear relationship, α) is constant, and the scaling constant (i.e., intercept of a log-log linear relationship, log β) varies with respect to environmental factors. However, little is known about whether the isometric scaling exponents of such biomass allocations remain invariant for single species, particularly conifers, at different altitudes and in different growing periods. In this study, we investigated how twig biomass allocation varies with elevation and period among Pinus hwangshanensis Hsia trees growing in the mountains of Southeast China. Specifically, we explored how twig stem mass, needle mass, and needle area varied throughout the growing period (early, mid-, late) and at three elevations in the Wuyi Mountains. Standardized major axis analysis was used to compare the scaling exponents and scaling constants between the biomass allocations of within-twig components. Scaling relationships between these traits differed with growing period and altitude gradient. During the different growing periods, there was an isometric scaling relationship, with a common slope of 1.0 (i.e., α ≈ 1.0), between needle mass and twig mass (the sum of the total needle mass and the stem mass), whereas there were allometric scaling relationships between the stem mass and twig mass and between the needle mass and stem mass of P. hwangshanensis. The scaling constants (log β) for needle mass vs. twig

  15. Economic viability of the construction and operation of a biomass gasificator for poultry houses heating

    Energy Technology Data Exchange (ETDEWEB)

    Zanatta, Fabio Luiz; Silva, Jadir Nogueira da; Tinoco, Ilda de Fatima Ferreira; Martin, Samuel; Melo, Lucas D.; Bueno, Mateus [Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola], E-mail: fzanatta@vicosa.ufv.br

    2008-07-01

    In all poultry farms, at least in the first days of life of the chicken, it is necessary to heat the environment to obtain a good development of the chicken and good economics results. However, this additional heat generation is sometimes neglected or not well executed, because of the costs that this practice could bring. This research has the objective of analyze the costs of construction and operation of a Biomass Gasificator for Poultry Houses Heating in comparison with a direct furnace system. The fuel used in both systems was firewood of eucalyptus. For so much, economic analyzes was make considering the costs of the gasification systems implementation in substitution of the traditional system used in the company (direct furnace system). For the viability the adopted method was the partial budget and the complementary investments were analyzed through the cash flow elaboration and of determination of indicator of economic feasibility. (author)

  16. Scale-up guidelines for a circulating fluidized bed biomass pyrolyzer

    Energy Technology Data Exchange (ETDEWEB)

    Haslinger, W.; Hofbauer, H. [Technische Univ., Vienna (Austria); Gavriil, L.; Boukis, I. [Center for Renewable Energy Sources (Greece)

    1999-07-01

    A new circulating fluidized bed design has been proposed and successfully operated at lab scale (10 kg/h biomass feed). This fluidized bed system consists of a bubbling bottom bed, above this bottom bed a riser, a cyclone and a return leg. The heat necessary for the pyrolysis process is produced in the bottom bed by burning some solid residue from the pyrolysis that circulates together with the bed material as the bottom bed is fluidized with air. The flue gas from the bottom bed enters into the riser and serves there as transport gas. The circulation rate is very sensitive to the amount of bed inventory and the fluidization velocities. As the riser uses the flue gas of the dense bottom bed the ratio of the cross sections of the two fluidized beds has to be in a certain range to get a satisfying operation. The fluid mechanic behavior of this new circulating fluidized bed pyrolyzer has been studied using three different cold flow models. One cold flow model was built for the existing 10 kg/h lab scale pyrolyzer according to Glicksman's (1984) similarity rules. The purpose of this cold model was to study the fluid mechanics and optimize the performance with respect to the pyrolysis process. For scale-up purposes further cold flow models (135 kg/h, 1000 kg/h) have been designed, built and investigated intensively. The idea and the new design of the pyrolyzer, the results of the experimental work as well as the scale-up criteria will be presented. (orig.)

  17. Performance Evaluation of a Lithium-Chloride Absorption Refrigeration and an Assessment of Its Suitability for Biomass Waste Heat

    Directory of Open Access Journals (Sweden)

    Sacha Oberweis

    2012-10-01

    Full Text Available This paper presents a computer model that will evaluate the performance of a thermo-chemical accumulator. The model is based on operational data such as temperatures and flow rates. The ultimate goal for this model is to estimate the coefficient of performance (COP of this unit when run on hot water from biomass combustion as the heat source. The outputs of the model are verified by comparing the simulation of the actual machine with published experimental data. The computed results for cooling COP are within 10% of the measured data. The simulations are all run for heat load temperatures varying between 80 °C and 110 °C. As expected, simulation results showed an increase in COP with increased heat source temperatures. The results demonstrate that the potential of combined solar and biomass combustion as a heat source for absorption cooling/heating in climates with low solar radiation can be coupled with biomass waste.

  18. Equilibrium simulation of a small scale gasification biomass CHP plant

    Energy Technology Data Exchange (ETDEWEB)

    Baggio, M.; Baratieri, M.; Grigiante, M. (Department of Environmental and Civil Engineering, University of Trento (Italy))

    2007-07-01

    One of the most important issues, in assessing the performance of IC engines fueled with biomass synthesis gas, is to have a good evaluation of the energy content of the producer gas per unit volume; in fact, as these are volumetric machines, it can be expected that the relevant properties are those of the inflow gas air mixture. For this purpose, in the present study a multiphase thermodynamic equilibrium analysis has been carried out providing an estimate of the gas composition and the yield of char along the conversion process. The aim of the present paper is then to provide a realistic estimate of the global energy efficiency of the process, by means of a whole balance of plant simulation; therefore, the enthalpy fluxes arising from the different components have been evaluated using the chemical equilibrium analysis for the reacting stages. The performed plant analysis demonstrates how the proposed coupling of a gasification reactor with an IC gas engine presents high conversion efficiencies and seems to be particularly suitable for distributed energy production, especially in small towns situated in rural zones, where there is often available a large quantity of biomass waste. (orig.)

  19. Improved control of a small-scale biomass boiler

    Energy Technology Data Exchange (ETDEWEB)

    Sulc, B.; Klimanek, D. [Czech Technical Univ., Prague (Czech Republic). Dept. of Fluid Dynamics and Power Engineering; Hrdlicka, J. [Czech Technical Univ., Prague (Czech Republic). Dept. of Fluid Dynamics and Power Engineering

    2007-07-01

    It is often difficult to detect errors in combustion chamber sensors. Sub-optimal combustion can lead to increased emissions of air pollutants and greenhouse gases (GHGs). Air flow must be controlled in order to reduce gaseous emissions and maintain steady fuel combustion rates. Oxygen sensor discredibility occurs when sensor properties have shifted to provide biased data. Gradual changes in the sensor can occur over time, causing oxygen control loops to react to incorrect information about the fuel-air ratio by attempting to remove unreal control errors. This paper described a control system designed to reduce emissions from an experimental biomass boiler equipped with an oxygen sensor. A valve and controller was used to control air flow for optimal combustion. The sensor discredibility detection method was based on a model of a control variable sensor modified to inform operators of changes when sensor parameters exceeded the limits of the tolerance range. The control system extended the function of standard controllers and detected imprecision in control loop operations while providing normal control functions. The design will be used to reduce the environmental footprint of larger biomass systems. 14 refs., 3 tabs., 3 figs.

  20. Burnout of pulverized biomass particles in large scale boiler – Single particle model approach

    DEFF Research Database (Denmark)

    Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero

    2010-01-01

    Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where...... the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner...

  1. Scaling-up vaccine production: implementation aspects of a biomass growth observer and controller

    NARCIS (Netherlands)

    Soons, Z.I.T.A.; IJssel, van den J.; Pol, van der L.A.; Straten, van G.; Boxtel, van A.J.B.

    2009-01-01

    Abstract This study considers two aspects of the implementation of a biomass growth observer and specific growth rate controller in scale-up from small- to pilot-scale bioreactors towards a feasible bulk production process for whole-cell vaccine against whooping cough. The first is the calculation

  2. Combined Heat and Power Systems for the Provision of Sustainable Energy from Biomass in Buildings

    Directory of Open Access Journals (Sweden)

    Ortwein Andreas

    2016-01-01

    Full Text Available Against the background of greenhouse gases causing climate change, combined heat and power (CHP systems fueled by biomass can efficiently supply energy with high flexibility. Such CHP systems will usually consist of one or more thermo-chemical conversion steps and at least one (the more or less separated electric power generation unit. Depending on the main products of the previous conversion steps (e.g. combustible gases or liquids, but also flue gases with sensible heat, different technologies are available for the final power conversion step. This includes steam cycles with steam turbines or engines and different working fluids (water, organic fluids, but also combustion based systems like gas turbines or gas engines. Further promising technologies include fuel cells with high electric efficiency. When integrating such CHP systems in buildings, there are different strategies, especially concerning electric power generation. While some concepts are focusing on base load production, others are regulated either by thermal or by electric power demand. The paper will give a systematic overview on the combination of thermo-chemical conversion of biomass and combined heat and power production technologies. The mentioned building integration strategies will be discussed, leading to conclusions for further research and development in that field.

  3. National scale biomass estimators for United States tree species

    Science.gov (United States)

    Jennifer C. Jenkins; David C. Chojnacky; Linda S. Heath; Richard A. Birdsey

    2003-01-01

    Estimates of national-scale forest carbon (C) stocks and fluxes are typically based on allometric regression equations developed using dimensional analysis techniques. However, the literature is inconsistent and incomplete with respect to large-scale forest C estimation. We compiled all available diameter-based allometric regression equations for estimating total...

  4. Local-Scale Mapping of Biomass in Tropical Lowland Pine Savannas Using ALOS PALSAR

    Directory of Open Access Journals (Sweden)

    Dimitrios Michelakis

    2014-09-01

    Full Text Available Fine-scale biomass maps offer forest managers the prospect of more detailed and locally accurate information for measuring, reporting and verification activities in contexts, such as sustainable forest management, carbon stock assessments and ecological studies of forest growth and change. In this study, we apply a locally validated method for estimating aboveground woody biomass (AGWB from Advanced Land Observing Satellite (ALOS Phased Array-type L-band Synthetic Aperture Radar (PALSAR data to produce an AGWB map for the lowland pine savannas of Belize at a spatial resolution of 100 m. Over 90% of these woodlands are predicted to have an AGWB below 60 tha−1, with the average woody biomass of these savannas estimated at 23.5 tha−1. By overlaying these spatial estimates upon previous thematic mapping of national land cover, we derive representative average biomass values of ~32 tha−1 and ~18 tha−1 for the previously qualitative classes of “denser” and “less dense” tree savannas. The predicted average biomass, from the mapping for savannas woodlands occurring within two of Belize’s larger protected areas, agree closely with previous biomass estimates for these areas based on ground surveys and forest inventories (error ≤20%. However, biomass estimates derived for these protected areas from two biomass maps produced at coarser resolutions (500 m and 1000 m from global datasets overestimated biomass (errors ≥275% in each dataset. The finer scale biomass mapping of both protected and unprotected areas provides evidence to suggest that protection has a positive effect upon woody biomass, with the mean AGWB higher in areas protected and managed for biodiversity (protected and passively managed (PRPM, 29.5 tha−1 compared to unprotected areas (UPR, 23.29 tha−1. These findings suggest that where sufficient ground data exists to build a reliable local relationship to radar backscatter, the more detailed biomass mapping that can be

  5. Biomass Energy for Transport and Electricity: Large scale utilization under low CO2 concentration scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Luckow, Patrick; Wise, Marshall A.; Dooley, James J.; Kim, Son H.

    2010-01-25

    This paper examines the potential role of large scale, dedicated commercial biomass energy systems under global climate policies designed to stabilize atmospheric concentrations of CO2 at 400ppm and 450ppm. We use an integrated assessment model of energy and agriculture systems to show that, given a climate policy in which terrestrial carbon is appropriately valued equally with carbon emitted from the energy system, biomass energy has the potential to be a major component of achieving these low concentration targets. The costs of processing and transporting biomass energy at much larger scales than current experience are also incorporated into the modeling. From the scenario results, 120-160 EJ/year of biomass energy is produced by midcentury and 200-250 EJ/year by the end of this century. In the first half of the century, much of this biomass is from agricultural and forest residues, but after 2050 dedicated cellulosic biomass crops become the dominant source. A key finding of this paper is the role that carbon dioxide capture and storage (CCS) technologies coupled with commercial biomass energy can play in meeting stringent emissions targets. Despite the higher technology costs of CCS, the resulting negative emissions used in combination with biomass are a very important tool in controlling the cost of meeting a target, offsetting the venting of CO2 from sectors of the energy system that may be more expensive to mitigate, such as oil use in transportation. The paper also discusses the role of cellulosic ethanol and Fischer-Tropsch biomass derived transportation fuels and shows that both technologies are important contributors to liquid fuels production, with unique costs and emissions characteristics. Through application of the GCAM integrated assessment model, it becomes clear that, given CCS availability, bioenergy will be used both in electricity and transportation.

  6. Simulated performance of biomass gasification based combined power and refrigeration plant for community scale application

    Science.gov (United States)

    Chattopadhyay, S.; Mondal, P.; Ghosh, S.

    2016-07-01

    Thermal performance analysis and sizing of a biomass gasification based combined power and refrigeration plant (CPR) is reported in this study. The plant is capable of producing 100 kWe of electrical output while simultaneously producing a refrigeration effect, varying from 28-68 ton of refrigeration (TR). The topping gas turbine cycle is an indirectly heated all-air cycle. A combustor heat exchanger duplex (CHX) unit burns producer gas and transfer heat to air. This arrangement avoids complex gas cleaning requirements for the biomass-derived producer gas. The exhaust air of the topping GT is utilized to run a bottoming ammonia absorption refrigeration (AAR) cycle via a heat recovery steam generator (HRSG), steam produced in the HRSG supplying heat to the generator of the refrigeration cycle. Effects of major operating parameters like topping cycle pressure ratio (rp) and turbine inlet temperature (TIT) on the energetic performance of the plant are studied. Energetic performance of the plant is evaluated via energy efficiency, required biomass consumption and fuel energy savings ratio (FESR). The FESR calculation method is significant for indicating the savings in fuel of a combined power and process heat plant instead of separate plants for power and process heat. The study reveals that, topping cycle attains maximum power efficiency of 30%in pressure ratio range of 8-10. Up to a certain value of pressure ratio the required air flow rate through the GT unit decreases with increase in pressure ratio and then increases with further increase in pressure ratio. The capacity of refrigeration of the AAR unit initially decreases up to a certain value of topping GT cycle pressure ratio and then increases with further increase in pressure ratio. The FESR is found to be maximized at a pressure ratio of 9 (when TIT=1100°C), the maximum value being 53%. The FESR is higher for higher TIT. The heat exchanger sizing is also influenced by the topping cycle pressure ratio and GT-TIT.

  7. Electron Heating at Kinetic Scales in Magnetosheath Turbulence

    Science.gov (United States)

    Chasapis, Alexandros; Matthaeus, W. H.; Parashar, T. N.; Lecontel, O.; Retino, A.; Breuillard, H.; Khotyaintsev, Y.; Vaivads, A.; Lavraud, B.; Eriksson, E.; hide

    2017-01-01

    We present a statistical study of coherent structures at kinetic scales, using data from the Magnetospheric Multiscale mission in the Earths magnetosheath. We implemented the multi-spacecraft partial variance of increments (PVI) technique to detect these structures, which are associated with intermittency at kinetic scales. We examine the properties of the electron heating occurring within such structures. We find that, statistically, structures with a high PVI index are regions of significant electron heating. We also focus on one such structure, a current sheet, which shows some signatures consistent with magnetic reconnection. Strong parallel electron heating coincides with whistler emissions at the edges of the current sheet.

  8. Pilot-scale radiofrequency blanching of potato cuboids: heating uniformity.

    Science.gov (United States)

    Zhang, Zhenna; Guo, Chaofan; Gao, Tong; Fu, Hongfei; Chen, Qin; Wang, Yunyang

    2018-01-01

    Traditional hot water blanching has a slow heat transfer rate, whereas radiofrequency (RF) heating has the advantages of a much faster heating rate and a higher penetration depth. In the present study, RF heating was applied to improve heating uniformity for subsequent blanching experiments involving potato cuboids. Potato cuboids were treated in a pilot-scale, RF heating system (27.12 MHz, 6 kW) under different operating conditions. The dielectric constant increased first and then decreased with temperature, whereas the loss factor increased as the temperature increased. The results of the present study reveal that the electrode gap, sample height and NaCl solution had significant effects (P uniformity of the sample after RF heating. The optimum RF heating uniformity was obtained at an electrode gap of 120 mm, a sample height of 60 mm and when immersed in NaCl solution of 0.5 s m-1 . The central heating pattern was presented in a sample. Cold spots were located at the edge of the top surface of the sample. The present study shows the great potential of RF heating for the blanching of vegetables. Future studies should aim to determine changes in the texture and nutrient contents of vegetables during RF heating. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Lidar aboveground vegetation biomass estimates in shrublands: Prediction, uncertainties and application to coarser scales

    Science.gov (United States)

    Li, Aihua; Dhakal, Shital; Glenn, Nancy F.; Spaete, Luke P.; Shinneman, Douglas; Pilliod, David; Arkle, Robert; McIlroy, Susan

    2017-01-01

    Our study objectives were to model the aboveground biomass in a xeric shrub-steppe landscape with airborne light detection and ranging (Lidar) and explore the uncertainty associated with the models we created. We incorporated vegetation vertical structure information obtained from Lidar with ground-measured biomass data, allowing us to scale shrub biomass from small field sites (1 m subplots and 1 ha plots) to a larger landscape. A series of airborne Lidar-derived vegetation metrics were trained and linked with the field-measured biomass in Random Forests (RF) regression models. A Stepwise Multiple Regression (SMR) model was also explored as a comparison. Our results demonstrated that the important predictors from Lidar-derived metrics had a strong correlation with field-measured biomass in the RF regression models with a pseudo R2 of 0.76 and RMSE of 125 g/m2 for shrub biomass and a pseudo R2 of 0.74 and RMSE of 141 g/m2 for total biomass, and a weak correlation with field-measured herbaceous biomass. The SMR results were similar but slightly better than RF, explaining 77–79% of the variance, with RMSE ranging from 120 to 129 g/m2 for shrub and total biomass, respectively. We further explored the computational efficiency and relative accuracies of using point cloud and raster Lidar metrics at different resolutions (1 m to 1 ha). Metrics derived from the Lidar point cloud processing led to improved biomass estimates at nearly all resolutions in comparison to raster-derived Lidar metrics. Only at 1 m were the results from the point cloud and raster products nearly equivalent. The best Lidar prediction models of biomass at the plot-level (1 ha) were achieved when Lidar metrics were derived from an average of fine resolution (1 m) metrics to minimize boundary effects and to smooth variability. Overall, both RF and SMR methods explained more than 74% of the variance in biomass, with the most important Lidar variables being associated with vegetation structure

  10. Scaling Study of Reconnection Heating in Torus Plasma Merging Experiments

    Science.gov (United States)

    Ono, Yasushi; Akimitsu, Moe; Sawada, Asuka; Cao, Qinghong; Koike, Hideya; Hatano, Hironori; Kaneda, Taishi; Tanabe, Hiroshi

    2017-10-01

    We have been investigating toroidal plasma merging and reconnection for high-power heating of spherical tokamak (ST) and field-reversed configuration (FRC), using TS-3 (ST, FRC: R =0.2m, 1985-), TS-4 (ST, FRC: R =0.5m, 2000-), UTST (ST: R =0.45m, 2008-) and MAST (ST: R =0.9m, 2000-) devices. The series of merging experiments made clear the promising scaling and characteristics of reconnection heating: (i) its ion heating energy that scales with square of the reconnecting magnetic field Brec, (ii) its energy loss lower than 10%, (iii) its ion heating energy (in the downstream) 10 time larger than its electron heating energy (at around X-point) and (iv) low dependence of ion heating on the guide (toroidal) field Bg. The Brec2-scalingwas obtained when the current sheet was compressed to the order of ion gyrodadius. When the sheet was insufficiently compressed, the measured ion temperature was lower than the scaling prediction. Based on this scaling, we realized significant ion heating up to 1.2keV in MAST after 2D elucidation of ion heating up to 250eV in TS-3 [3,4]. This promising scaling leads us to new high Brec reconnection heating experiments for future direct access to burning plasma: TS-U (2017-) in Univ. Tokyo and ST-40 in Tokamak Energy Inc. (2017-). This presentation reviews major progresses in those toroidal plasma merging experiments for physics and fusion applications of magnetic reconnection.

  11. Wood wastes (biomass) supplying the central heating system of a housing project. Final report. Zentralbeheizung einer Siedlung mit Holzabfaellen (Biomasse). Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Heubrandner, P.; Schaup, P.; Streicher, W.

    1985-01-01

    Around 1980 a group of 21 young families joined to found the 'Wohnprojekt Thal' association. The housing project aimed at establishing a common residential quarter representing the members' idea and meeting the requirements of a housing area and economic heat supply. Buildings were erected in Thal which is located about 10 km northwest of Graz. The central heating system was chosen to be consisting of a top water heating system and central boiler for the processing of domestic biomass (barks and wood wastes). The final report points out the notably positive experiences gained with respect to the project's efficiency and economy.

  12. A renewable energy scenario for Aalborg Municipality based on low-temperature geothermal heat, wind power and biomass

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg; Mathiesen, Brian Vad; Möller, Bernd

    2010-01-01

    Aalborg Municipality, Denmark, wishes to investigate the possibilities of becoming independent of fossil fuels. This article describes a scenario for supplying Aalborg Municipality’s energy needs through a combination of low-temperature geothermal heat, wind power and biomass. Of particular focus...... in the scenario is how low-temperature geothermal heat may be utilised in district heating (DH) systems. The analyses show that it is possible to cover Aalborg Municipality’s energy needs through the use of locally available sources in combination with significant electricity savings, heat savings, reductions...... in industrial fuel use and savings and fuel-substitutions in the transport sector. With biomass resources being finite, the two marginal energy resources in Aalborg are geothermal heat and wind power. If geothermal heat is utilised more, wind power may be limited and vice versa. The system still relies...

  13. Influence of biomass cofiring on the optimal coefficient of the cogeneration share in a district heating system

    Science.gov (United States)

    Ziębik, Andrzej; Gładysz, Paweł

    2014-03-01

    The paper presents a modified algorithm for choosing the optimal coefficient of the share of cogeneration in district heating systems taking into account additional benefits concerning the promotion of highefficiency cogeneration and biomass cofiring. The optimal coefficient of the share of cogeneration depends first of all on the share of the heat required for preparing the hot tap water. The final result of investigations is an empirical equation describing the influence of the ratio of the heat flux for the production of hot tap water to the maximum flux for space heating and ventilation, as well as the share of chemical energy of biomass in the fuel mixture on the optimal value of the share of cogeneration in district heating systems. The approach presented in the paper may be applied both in back-pressure combined heat and power (CHP) plants and in extraction-condensing CHP plants.

  14. Mushroom biomass and diversity are driven by different spatio-temporal scales along Mediterranean elevation gradients

    Science.gov (United States)

    Alday, Josu G.; Martínez de Aragón, Juan; de-Miguel, Sergio; Bonet, José Antonio

    2017-04-01

    Mushrooms are important non-wood-forest-products in many Mediterranean ecosystems, being highly vulnerable to climate change. However, the ecological scales of variation of mushroom productivity and diversity, and climate dependence has been usually overlooked due to a lack of available data. We determined the spatio-temporal variability of epigeous sporocarps and the climatic factors driving their fruiting to plan future sustainable management of wild mushrooms production. We collected fruiting bodies in Pinus sylvestris stands along an elevation gradient for 8 consecutive years. Overall, sporocarp biomass was mainly dependent on inter-annual variations, whereas richness was more spatial-scale dependent. Elevation was not significant, but there were clear elevational differences in biomass and richness patterns between ectomycorrhizal and saprotrophic guilds. The main driver of variation was late-summer-early-autumn precipitation. Thus, different scale processes (inter-annual vs. spatial-scale) drive sporocarp biomass and diversity patterns; temporal effects for biomass and ectomycorrhizal fungi vs. spatial scale for diversity and saprotrophic fungi. The significant role of precipitation across fungal guilds and spatio-temporal scales indicates that it is a limiting resource controlling sporocarp production and diversity in Mediterranean regions. The high spatial and temporal variability of mushrooms emphasize the need for long-term datasets of multiple spatial points to effectively characterize fungal fruiting patterns.

  15. Laboratory Scale Coal And Biomass To Drop-In Fuels (CBDF) Production And Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lux, Kenneth [Altex Technologies Corporation, Sunnyvale, CA (United States); Imam, Tahmina [Altex Technologies Corporation, Sunnyvale, CA (United States); Chevanan, Nehru [Altex Technologies Corporation, Sunnyvale, CA (United States); Namazian, Mehdi [Altex Technologies Corporation, Sunnyvale, CA (United States); Wang, Xiaoxing [Pennsylvania State Univ., University Park, PA (United States); Song, Chunshan [Pennsylvania State Univ., University Park, PA (United States)

    2016-06-29

    This Final Technical Report describes the work and accomplishments of the project entitled, “Laboratory Scale Coal and Biomass to Drop-In Fuels (CBDF) Production and Assessment.” The main objective of the project was to fabricate and test a lab-scale liquid-fuel production system using coal containing different percentages of biomass such as corn stover and switchgrass at a rate of 2 liters per day. The system utilizes the patented Altex fuel-production technology, which incorporates advanced catalysts developed by Pennsylvania State University. The system was designed, fabricated, tested, and assessed for economic and environmental feasibility relative to competing technologies.

  16. Catalytically supported reduction of emissions from small-scale biomass furnace systems; Katalytisch unterstuetzte Minderung von Emissionen aus Biomasse-Kleinfeuerungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Ingo; Lenz, Volker; Schenker, Marian; Thiel, Christian [DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH, Leipzig (Germany); Kraus, Markus; Matthes, Mirjam; Roland, Ulf [Helmholtz-Zentrum fuer Umweltforschung GmbH - UFZ, Leipzig (Germany); Bindig, Rene; Einicke, Wolf-Dietrich [Leipzig Univ. (Germany)

    2011-06-29

    The increased use of solid biomass in small combustion for generating heat from renewable energy sources is unfortunately associated with increased emissions of airborne pollutants. The reduction is possible on the one hand by the use of high-quality modern furnaces to the latest state of the art. On the other hand, several promising approaches method for retrofitting small-scale furnaces are currently being developed that will allow an effective emission reduction by the subsequent treatment of the exhaust gas. The overview of current available emission control technologies for small-scale biomass combustion plants shows that there is still considerable need for research on the sustainable production of heat from solid biofuels. The amendment to the 1st BImSchV provides a necessary drastic reduction of discharged pollutants from small-scale biomass furnaces. When using the fuel wood in modern central heating boilers the required limits can be met at full load. However, dynamic load changes can cause brief dramatic emission increases even with wood central heating boilers. Firebox and control optimization must contribute in the future to a further reduction of emissions. The typical simple single-room fireplaces like hand-fed wood stoves are suitable under type test conditions to comply the limit values. By contrast, in practical operation, the harmful gas emissions be exceeded without secondary measures normally. The performed experimental investigations show that a reduction of both CO and of organic compounds by catalytic combustion is possible. In addition to developing specially adapted catalysts, it is necessary to provide additional dust separation by combined processes, since conventional catalysts are not suitable for deposition and retention of particulate matter or would lose their activity due to dust accumulation on the active surface, when the catalyst would act as a filter at the same time. To enable sufficiently high reaction temperatures and thus a

  17. Inventory of future power and heat production technologies. Partial report Gasification with gas turbine/engine for power plants; Incl. English lang. appendix of 24 p. titled 'Status of large-scale biomass gasification for power production'; Inventering av framtidens el och vaermeproduktionstekniker. Delrapport Foergasning med gasturbin/motor foer kraftvaerk

    Energy Technology Data Exchange (ETDEWEB)

    Waldheim, Lars; Larsson, Eva K. (TPS Termiska Processer, Nykoeping (Sweden))

    2008-12-15

    operation because of contract problems and a number of projects in Holland, Italy and Brazil never got to a construction phase. Indirect co-firing has been realised in a few plants where a CFB gasifier is combined with some cooling and cyclone particle removal. If gas cleaning before firing can be achieved, the technology is believed to have a bigger potential. That would mean that waste fuel or other fuels with high chlorine content can be used, and also that the treated gas can be used in an incineration plant without limiting the superheater temperature to the low levels, in relation to power plant boilers, that is used in waste boilers. This means that both the efficiency to electricity and the ratio between electricity and heat production can be increased, in relation to waste incineration. Improvements in performance during the time period in question require that initiatives are taken and that e.g. gas turbine manufacturers participate actively. The probability for this development is more difficult to assess. For BIG-ICE, the technology is assessed to reach 35-40 % electricity efficiency at the end of the period, i.e. 2025-2030, and the investment cost for bigger plants can be just below that of comparable conventional steam plants, perhaps 3 000 Euro/kWe for a complete plant. Completely commercial technology can be expected at the beginning of the 2020's. For BIG-CC the corresponding assessment is 45-50 % and 2500-3000 Euro/kWe. The route to commercial technology is longer in this case and plants on near commercial conditions cannot be expected until the end of the 2020's. For indirect co-firing it is a fact that lime kiln gasifiers and the gasifiers in Lahti, Ruien and Getruidenberg, without extensive gas cleaning, are in a commercial scale and that years of operation experiences already have been earned, also with waste fuels. The energy conversion to electricity uses existing infrastructure and therefore the adoption requirements are very limited. What

  18. Exploring multi-scale forest above ground biomass estimation with optical remote sensing imageries

    Science.gov (United States)

    Koju, U.; Zhang, J.; Gilani, H.

    2017-02-01

    Forest shares 80% of total exchange of carbon between the atmosphere and the terrestrial ecosystem. Due to this monitoring of forest above ground biomass (as carbon can be calculated as 0.47 part of total biomass) has become very important. Forest above ground biomass as being the major portion of total forest biomass should be given a very careful consideration in its estimation. It is hoped to be useful in addressing the ongoing problems of deforestation and degradation and to gain carbon mitigation benefits through mechanisms like Reducing Emissions from Deforestation and Forest Degradation (REDD+). Many methods of above ground biomass estimation are in used ranging from use of optical remote sensing imageries of very high to very low resolution to SAR data and LIDAR. This paper describes a multi-scale approach for assessing forest above ground biomass, and ultimately carbon stocks, using very high imageries, open source medium resolution and medium resolution satellite datasets with a very limited number of field plots. We found this method is one of the most promising method for forest above ground biomass estimation with higher accuracy and low cost budget. Pilot study was conducted in Chitwan district of Nepal on the estimation of biomass using this technique. The GeoEye-1 (0.5m), Landsat (30m) and Google Earth (GE) images were used remote sensing imageries. Object-based image analysis (OBIA) classification technique was done on Geo-eye imagery for the tree crown delineation at the watershed level. After then, crown projection area (CPA) vs. biomass model was developed and validated at the watershed level. Open source GE imageries were used to calculate the CPA and biomass from virtual plots at district level. Using data mining technique, different parameters from Landsat imageries along with the virtual sample biomass were used for upscaling biomass estimation at district level. We found, this approach can considerably reduce field data requirements for

  19. Enhancing biomass energy yield from pilot-scale high rate algal ponds with recycling.

    Science.gov (United States)

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-01

    This paper investigates the effect of recycling on biomass energy yield in High Rate Algal Ponds (HRAPs). Two 8 m(3) pilot-scale HRAPs treating primary settled sewage were operated in parallel and monitored over a 2-year period. Volatile suspended solids were measured from both HRAPs and their gravity settlers to determine biomass productivity and harvest efficiency. The energy content of the biomass was also measured. Multiplying biomass productivity and harvest efficiency gives the 'harvestable biomass productivity' and multiplying this by the energy content defines the actual 'biomass energy yield'. In Year 1, algal recycling was implemented in one of the ponds (HRAPr) and improved harvestable biomass productivity by 58% compared with the control (HRAPc) without recycling (HRAPr: 9.2 g/m(2)/d; HRAPc: 5.8 g/m(2)/d). The energy content of the biomass grown in HRAPr, which was dominated by Pediastrun boryanum, was 25% higher than the control HRAPc which contained a mixed culture of 4-5 different algae (HRAPr: 21.5 kJ/g; HRAPc: 18.6 kJ/g). In Year 2, HRAPc was then seeded with the biomass harvested from the P. boryanum dominated HRAPr. This had the effect of shifting algal dominance from 89% Dictyosphaerium sp. (which is poorly-settleable) to over 90% P. boryanum in 5 months. Operation of this pond was then switched to recycling its own harvested biomass, which maintained P. boryanum dominance for the rest of Year 2. This result confirms, for the first time in the literature, that species control is possible for similarly sized co-occurring algal colonies in outdoor HRAP by algal recycling. With regard to the overall improvement in biomass energy yield, which is a critical parameter in the context of algal cultivation for biofuels, the combined improvements that recycling triggered in biomass productivity, harvest efficiency and energy content enhanced the harvested biomass energy yield by 66% (HRAPr: 195 kJ/m(2)/day; HRAPc: 118 kJ/m(2)/day). Copyright © 2013

  20. Small-scale processing of biomass for biorefinery

    NARCIS (Netherlands)

    Bruins, M.E.; Sanders, J.P.M.

    2012-01-01

    The current fossil-based economy is moving towards a more bio-based economy. To enable this transition, many different processes for biorefinery are being developed. Small-scale biorefinery processes can be beneficial, not only socially and ecologically, but also economically. The main motivation

  1. Devolatilization kinetics of woody biomass at short residence times and high heating rates and peak temperatures

    DEFF Research Database (Denmark)

    Johansen, Joakim M.; Gadsbøll, Rasmus; Thomsen, Jesper

    2016-01-01

    This work combines experimental and computational fluid dynamics (CFD) results to derive global kinetics for biomass (pine wood) devolatilization during heating rates on the order of 105Ks-1, bulk flow peak temperatures between 1405 and 1667K, and particle residence times below 0.1s. Experiments ...... faster kinetics than found in the literature, leading to predicted residence times required for full conversion one order of magnitude lower than when compared to thermogravimetric analysis (TGA) derived kinetics.......This work combines experimental and computational fluid dynamics (CFD) results to derive global kinetics for biomass (pine wood) devolatilization during heating rates on the order of 105Ks-1, bulk flow peak temperatures between 1405 and 1667K, and particle residence times below 0.1s. Experiments...... were conducted on a laboratory laminar entrained flow reactor (LFR) using solid fuel feed rates on the order of 10-20mgh-1. Employing a simple single step first order (SFOR) mechanism with an Arrhenius type rate expression, the best fit of the pyrolysis kinetics was found to be: A=18.9×103s-1, Ea=21305...

  2. Potential utilization of biomass in production of electricity, heat and transportation fuels including energy combines - Regional analyses and examples; Potentiell avsaettning av biomassa foer produktion av el, vaerme och drivmedel inklusive energikombinat - Regionala analyser och raekneexempel

    Energy Technology Data Exchange (ETDEWEB)

    Ericsson, Karin; Boerjesson, Paal

    2008-01-15

    The objective of this study is to analyse how the use of biomass may increase in the next 10-20 years in production of heat, electricity and transportation fuels in Sweden. In these analyses, the biomass is assumed to be used in a resource and cost efficient way. This means for example that the demand for heat determines the potential use of biomass in co-generation of heat and electricity and in energy combines, and that the markets for by-products determine the use of biomass in production of certain transportation fuels. The economic conditions are not analysed in this study. In the heat and electricity production sector, we make regional analyses of the potential use of biomass in production of small-scale heat, district heat, process heat in the forest industry and electricity produced in co-generation with heat in the district heating systems and forest industry. These analyses show that the use of biomass in heat and electricity production could increase from 87 TWh (the use in 2004/2005, excluding small-scale heat production with firewood) to between 113 TWh and 134 TWh, depending on the future expansion of the district heating systems. Geographically, the Stockholm province accounts for a large part of the potential increase owing to the great opportunities for increasing the use of biomass in production of district heat and CHP in this region. In the sector of transportation fuels we applied a partly different approach since we consider the market for biomass-based transportation fuels to be 'unconstrained' within the next 10-20 years. Factors that constrain the production of these fuels are instead the availability of biomass feedstock and the local conditions required for achieving effective production systems. Among the first generation biofuels this report focuses on RME and ethanol from cereals. We estimate that the domestic production of RME and ethanol could amount to up to 1.4 TWh/y and 0.7-3.8 TWh/y, respectively, where the higher

  3. Gas, power and heat generation from biomass by allothermal gasification; Gas-, Strom- und Waermeerzeugung aus Biomasse durch allotherme Vergasung

    Energy Technology Data Exchange (ETDEWEB)

    Yaqub Chughtai, M. [H und C Engineering GmbH, Gummersbach (Germany); Muehlen, H.J. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany)

    1998-09-01

    The allothermal DMT gasification process for biomass is a newcomer. The process, its initial materials, the uses of the product gas, and advantages of the allothermal process are described here. (orig./SR) [Deutsch] Der Einsatz des allothermen DMT-Vergasungsverfahrens fuer Biomasse ist neu. Verfahren, Einsatzstoffe und Produktgasnutzung, sowie Vorteile des allothermen Verfahrens werden hier beschrieben. (orig./SR)

  4. Thermal distillation system utilizing biomass energy burned in stove by means of heat pipe

    Directory of Open Access Journals (Sweden)

    Hiroshi Tanaka

    2016-09-01

    Full Text Available A thermal distillation system utilizing a part of the thermal energy of biomass burned in a stove during cooking is proposed. The thermal energy is transported from the stove to the distiller by means of a heat pipe. The distiller is a vertical multiple-effect diffusion distiller, in which a number of parallel partitions in contact with saline-soaked wicks are set vertically with narrow gaps of air. A pilot experimental apparatus was constructed and tested with a single-effect and multiple-effect distillers to investigate primarily whether a heat pipe can transport thermal energy adequately from the stove to the distiller. It was found that the temperatures of the heated plate and the first partition of the distiller reached to about 100 °C and 90 °C, respectively, at steady state, showing that the heat pipe works sufficiently. The distilled water obtained was about 0.75 and 1.35 kg during the first 2 h of burning from a single-effect and multiple-effect distillers, respectively.

  5. Large Scale Solar Heating:Evaluation, Modelling and Designing

    OpenAIRE

    Heller, Alfred; Svendsen, Svend; Furbo, Simon

    2001-01-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out based on measurements on the Marstal plant, Denmark, and through comparison with published and unpublished data from other plants. Evaluations on the thermal, economical and environmental performance...

  6. Performance of a pilot-scale, steam-blown, pressurized fluidized bed biomass gasifier

    Science.gov (United States)

    Sweeney, Daniel Joseph

    With the discovery of vast fossil resources, and the subsequent development of the fossil fuel and petrochemical industry, the role of biomass-based products has declined. However, concerns about the finite and decreasing amount of fossil and mineral resources, in addition to health and climate impacts of fossil resource use, have elevated interest in innovative methods for converting renewable biomass resources into products that fit our modern lifestyle. Thermal conversion through gasification is an appealing method for utilizing biomass due to its operability using a wide variety of feedstocks at a wide range of scales, the product has a variety of uses (e.g., transportation fuel production, electricity production, chemicals synthesis), and in many cases, results in significantly lower greenhouse gas emissions. In spite of the advantages of gasification, several technical hurdles have hindered its commercial development. A number of studies have focused on laboratory-scale and atmospheric biomass gasification. However, few studies have reported on pilot-scale, woody biomass gasification under pressurized conditions. The purpose of this research is an assessment of the performance of a pilot-scale, steam-blown, pressurized fluidized bed biomass gasifier. The 200 kWth fluidized bed gasifier is capable of operation using solid feedstocks at feedrates up to 65 lb/hr, bed temperatures up to 1600°F, and pressures up to 8 atm. Gasifier performance was assessed under various temperatures, pressure, and feedstock (untreated woody biomass, dark and medium torrefied biomass) conditions by measuring product gas yield and composition, residue (e.g., tar and char) production, and mass and energy conversion efficiencies. Elevated temperature and pressure, and feedstock pretreatment were shown to have a significant influence on gasifier operability, tar production, carbon conversion, and process efficiency. High-pressure and temperature gasification of dark torrefied biomass

  7. Catalysts for dual fluidised bed biomass gasification - an experimental study at the pilot plant scale

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Christoph; Koppatz, Stefan; Hofbauer, Hermann [Vienna University of Technology, Institute of Chemical Engineering, Vienna (Austria)

    2011-07-15

    Energy from renewable sources is expected to contribute increasingly to the future energy supply. Particularly, the utilisation of biomass via gasification features a high potential for local energy supply. In addition to the conventional heat and power supply, the biomass-derived product gas is utilisable for further conversion, e.g. into liquid fuels, synthetic natural gas or even chemicals. In the field of biomass gasification systems, fluidised bed gasification has achieved notable relevance. Biomass gasification by fluidised bed processing produces high-quality product gas. However, the technical and economical effectiveness is not yet competitive. A major issue is the purity of the product gas, which is mainly focused on the gasification originating tar. A promising option to yield tar-free product gas is the application of a catalyst directly in the fluidised bed process. The present paper outlines catalysts for biomass gasification in fluidised bed processing. Recent activities in the development of gasifier catalysts are highlighted. Different catalysts are described depending on their performance and capability regarding tar conversion. The scope of catalysts ranges from naturally occurring materials to synthetic materials. (orig.)

  8. Biomass logistics analysis for large scale biofuel production: case study of loblolly pine and switchgrass.

    Science.gov (United States)

    Lu, Xiaoming; Withers, Mitch R; Seifkar, Navid; Field, Randall P; Barrett, Steven R H; Herzog, Howard J

    2015-05-01

    The objective of this study was to assess the costs, energy consumption and greenhouse gas (GHG) emissions throughout the biomass supply chain for large scale biofuel production. Two types of energy crop were considered, switchgrass and loblolly pine, as representative of herbaceous and woody biomass. A biomass logistics model has been developed to estimate the feedstock supply system from biomass production through transportation. Biomass in the form of woodchip, bale and pellet was investigated with road, railway and waterway transportation options. Our analysis indicated that the farm or forest gate cost is lowest for loblolly pine whole tree woodchip at $39.7/dry tonne and highest for switchgrass round bale at $72.3/dry tonne. Switchgrass farm gate GHG emissions is approximately 146kgCO2e/dry tonne, about 4 times higher than loblolly pine. The optimum biomass transportation mode and delivered form are determined by the tradeoff between fixed and variable costs for feedstock shipment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Design and System Analysis of Quad-Generation Plant Based on Biomass Gasification Integrated with District Heating

    DEFF Research Database (Denmark)

    Rudra, Souman

    This thesis presents the development of energy system for simulation, techno-economic optimization and design of a quad-generation energy system based on biomass gasification. An efficient way of reducing CO2 emission from the environment is by increasing the use of biomass in the energy sector......, it possible to lay a foundation for future gasification based power sector to produce flexible output such as electricity, heat, chemicals or bio-fuels by improving energy system of existing DHP(district heating plant) integrating gasification technology. The present study investigate energy system...... in this study. The overall aim of this work is to provide a complete assessment of the technical potential of biomass gasification for local heat and power supply in Denmark and replace of natural gas for the production. This study also finds and defines the future areas of research in the gasification...

  10. Decentralized combined heat and power production by two-stage biomass gasification and solid oxide fuel cells

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud; Elmegaard, Brian

    2013-01-01

    To investigate options for increasing the electrical efficiency of decentralized combined heat and power (CHP) plants fuelled with biomass compared to conventional technology, this research explored the performance of an alternative plant design based on thermal biomass gasification and solid oxide...... fuel cells (SOFC). Based on experimental data from a demonstrated 0.6 MWth two-stage gasifier, a model of the gasifier plant was developed and calibrated. Similarly, an SOFC model was developed using published experimental data. Simulation of a 3 MWth plant combining two-stage biomass gasification...

  11. Scaling-up vaccine production: implementation aspects of a biomass growth observer and controller.

    Science.gov (United States)

    Soons, Zita I T A; van den IJssel, Jan; van der Pol, Leo A; van Straten, Gerrit; van Boxtel, Anton J B

    2009-04-01

    This study considers two aspects of the implementation of a biomass growth observer and specific growth rate controller in scale-up from small- to pilot-scale bioreactors towards a feasible bulk production process for whole-cell vaccine against whooping cough. The first is the calculation of the oxygen uptake rate, the starting point for online monitoring and control of biomass growth, taking into account the dynamics in the gas-phase. Mixing effects and delays are caused by amongst others the headspace and tubing to the analyzer. These gas phase dynamics are modelled using knowledge of the system in order to reconstruct oxygen consumption. The second aspect is to evaluate performance of the monitoring and control system with the required modifications of the oxygen consumption calculation on pilot-scale. In pilot-scale fed-batch cultivation good monitoring and control performance is obtained enabling a doubled concentration of bulk vaccine compared to standard batch production.

  12. Pore-Scale Investigation of Biomass Plug Development and Propagation in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Terri L.; Fogler, H S.

    2002-01-09

    Biomass plugging of porous media finds application in enhanced oil recovery and bioremediation. An understanding of biomass plugging of porous media was sought by using a porous glass micromodel through which biomass and nutrient were passed. This paper describes the pore-scale physics of biomass plug propagation of Leuconostoc mesenteroides under nutrient-rich conditions. It was found that as the nutrient flowed through the micromodel, the initial biomass plug occurred at the nutrient-inoculum interface due to growth in the larger pore throats. As growth proceeded, biomass filled and closed these larger pore throats, until only isolated groupings of pore throats with smaller radii remained empty. As nutrient flow continued, a maximum pressure drop was reached. At the maximum pressure drop, the biomass yielded in a manner similar to a Bingham plastic to form a breakthrough channel consisting of a path of interconnected pore throats. The channel incorporated the isolated groupings of empty pore throats that had been present before breakthrough. As the nutrient flow continued, subsequent plugs developed as breakthrough channels refilled with biomass and in situ growth was stimulated in the region just downstream of the previous plug. The downstream plugs had a higher fraction of isolated groupings of empty pore throats which can be attributed to depletion of nutrient downstream. When the next breakthrough channel formed, it incorporated these isolated groupings, causing the breakthrough channels to be branched. It was observed that the newly formed plug could be less stable with this higher fraction of empty pore throats and that the location of breakthrough channels changed in subsequent plugs. This change in breakthrough channel location could be attributed to the redistribution of nutrient flow and the changes in flowrate in the pore throats.

  13. Characterization of biomass producer gas as fuel for stationary gas engines in combined heat and power production

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper

    2008-01-01

    different measuring methods. Likewise, no particles were detected in the gas. Considerable amounts of NH3 were measured in the produced gas.An analysis of engine operation at varying load has been carried out. Standard emissions, load and efficiency have been measured at varying operating conditions ranging......The aim of this project has been the characterization of biomass producer gas as a fuel for stationary gas engines in heat and power production. More than 3200 hours of gas engine operation, with producer gas as fuel, has been conducted at the biomass gasification combined heat and power (CHP...

  14. The land cover and carbon cycle consequences of large-scale utilizations of biomass as an energy source

    NARCIS (Netherlands)

    Leemans, R; vanAmstel, A; Battjes, C; Kreileman, E; Toet, S

    The use of modern biomass for energy generation has been considered in many studies as a possible measure for reducing or stabilizing global carbon dioxide (CO2) emissions. In this paper we assess the impacts of large-scale global utilization of biomass on regional and grid scale land cover,

  15. Universal model of slow pyrolysis technology producing biochar and heat from standard biomass needed for the techno-economic assessment.

    Science.gov (United States)

    Klinar, Dušan

    2016-04-01

    Biochar as a soil amendment and carbon sink becomes in last period one of the vast, interesting product of slow pyrolysis. Simplest and most used industrial process arrangement is a production of biochar and heat at the same time. Proposed mass and heat balance model consist of heat consumers (heat demand side) and heat generation-supply side. Direct burning of all generated uncondensed volatiles from biomass provides heat. Calculation of the mass and heat balance of both sides reveals the internal distribution of masses and energy inside process streams and units. Thermodynamic calculations verified not only the concept but also numerical range of the results. The comparisons with recent published scientific and vendors data prove its general applicability and reliability. The model opens the possibility for process efficiency innovations. Finally, the model was adapted to give more investors favorable results and support techno-economic assessments entirely. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Small-scale CHP Plant based on a 35 kWel Hermetic Four Cylinder Stirling Engine for Biomass Fuels- Development, Technology and Operating Experiences

    DEFF Research Database (Denmark)

    Obernberger, I.; Carlsen, Henrik; Biedermann, F.

    2003-01-01

    ) process and the Stirling engine process. The ORC process represents an economically interesting technology for small-scale biomass-fired combined heat and power plants in a power range between 400 and 1,500 kWel. A newly developed ORC technology with a nominal electric capacity of 1,000 kW was implemented...... in the biomass CHP plant Lienz (A) in the framework of an EU demonstration project. This plant was put in operation in February 2002. Stirling engines are a promising solution for installations with nominal electric capacities between 10 and 150 kW. A biomass CHP pilot plant based on a 35 kWel-Stirling engine...

  17. Bioprocess engineering for biohythane production from low-grade waste biomass: technical challenges towards scale up.

    Science.gov (United States)

    Liu, Zhidan; Si, Buchun; Li, Jiaming; He, Jianwei; Zhang, Chong; Lu, Yuan; Zhang, Yuanhui; Xing, Xin-Hui

    2017-09-08

    A concept of biohythane production by combining biohydrogen and biomethane together via two-stage anaerobic fermentation (TSAF) has been recently proposed and considered as a promising approach for sustainable hythane generation from waste biomass. The advantage of biohythane over traditional biogas are more environmentally benign, higher energy recovery and shorter fermentation time. However, many of current efforts to convert waste biomass into biohythane are still at the bench scale. The system bioprocess study and scale up for industrial application are indispensable. This paper outlines the general approach of biohythane by comparing with other biological processes. The technical challenges are highlighted towards scale up of biohythane system, including functionalization of biohydrogen-producing reactor, energy efficiency, and bioprocess engineering of TSAF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Heat transfer at nanometric scales described by extended irreversible thermodynamics

    Directory of Open Access Journals (Sweden)

    Machrafi Hatim

    2016-06-01

    Full Text Available The purpose of this work is to present a study on heat conduction in systems that are composed out of spherical and cylindrical micro- and nanoparticles dispersed in a bulk matrix. Special emphasis is put on the dependence of the effective heat conductivity on various selected parameters as particle size and also its shape, surface specularity and density, including particle-matrix interaction. The heat transfer at nanometric scales is modelled using extended irreversible thermodynamics, whose main feature is to elevate the heat flux vector to the status of independent variable. The model is illustrated by a Copper-Silicium (Cu-Si system. It is shown that all the investigated parameters have a considerable influence, the particle size being especially useful to either increase or decrease the effective thermal conductivity.

  19. Modeling and experiments of biomass combustion in a large-scale grate boiler

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2007-01-01

    is exposed to preheated inlet air while the top of the bed resides within the furnace. Mathematical modeling is an efficient way to understand and improve the operation and design of combustion systems. Compared to modeling of pulverized fuel furnaces, CFD modeling of biomass-fired grate furnaces...... is inherently more difficult due to the complexity of the solid biomass fuel bed on the grate, the turbulent reacting flow in the combustion chamber and the intensive interaction between them. This paper presents the CFD validation efforts for a modern large-scale biomass-fired grate boiler. Modeling...... quite much with the conditions in the real furnace. Combustion instabilities in the fuel bed impose big challenges to give reliable grate inlet BCs for the CFD modeling; the deposits formed on furnace walls and air nozzles make it difficult to define precisely the wall BCs and air jet BCs...

  20. Simulated performance of biomass gasification based combined power and refrigeration plant for community scale application

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S., E-mail: suman.mech09@gmail.com [Department of Mechanical Engineering, NIT, Agarpara, Kolkata – 700109, West Bengal (India); Mondal, P., E-mail: mondal.pradip87@gmail.com; Ghosh, S., E-mail: sudipghosh.becollege@gmail.com [Department of Mechanical Engineering, IIEST, Shibpur, Howrah – 711103, West Bengal (India)

    2016-07-12

    Thermal performance analysis and sizing of a biomass gasification based combined power and refrigeration plant (CPR) is reported in this study. The plant is capable of producing 100 kWe of electrical output while simultaneously producing a refrigeration effect, varying from 28-68 ton of refrigeration (TR). The topping gas turbine cycle is an indirectly heated all-air cycle. A combustor heat exchanger duplex (CHX) unit burns producer gas and transfer heat to air. This arrangement avoids complex gas cleaning requirements for the biomass-derived producer gas. The exhaust air of the topping GT is utilized to run a bottoming ammonia absorption refrigeration (AAR) cycle via a heat recovery steam generator (HRSG), steam produced in the HRSG supplying heat to the generator of the refrigeration cycle. Effects of major operating parameters like topping cycle pressure ratio (r{sub p}) and turbine inlet temperature (TIT) on the energetic performance of the plant are studied. Energetic performance of the plant is evaluated via energy efficiency, required biomass consumption and fuel energy savings ratio (FESR). The FESR calculation method is significant for indicating the savings in fuel of a combined power and process heat plant instead of separate plants for power and process heat. The study reveals that, topping cycle attains maximum power efficiency of 30%in pressure ratio range of 8-10. Up to a certain value of pressure ratio the required air flow rate through the GT unit decreases with increase in pressure ratio and then increases with further increase in pressure ratio. The capacity of refrigeration of the AAR unit initially decreases up to a certain value of topping GT cycle pressure ratio and then increases with further increase in pressure ratio. The FESR is found to be maximized at a pressure ratio of 9 (when TIT=1100°C), the maximum value being 53%. The FESR is higher for higher TIT. The heat exchanger sizing is also influenced by the topping cycle pressure ratio

  1. Large scale solar district heating. Evaluation, modelling and designing - Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The appendices present the following: A) Cad-drawing of the Marstal CSHP design. B) Key values - large-scale solar heating in Denmark. C) Monitoring - a system description. D) WMO-classification of pyranometers (solarimeters). E) The computer simulation model in TRNSYS. F) Selected papers from the author. (EHS)

  2. Scaling-up the biomass production of Cymbopogon citratus L. in temporary immersion system

    Directory of Open Access Journals (Sweden)

    Elisa Quiala

    2014-04-01

    Full Text Available Shoot-tips, collected from greenhouse-grown plants of Cymbopogon citratus L. (lemmon grass, were incubated on a semi-solid Murashige and Skoog (MS medium with 30% (w/v sucrose, and supplemented with 0.89 µM 6-benzyladenine (BA. After three weeks of culture shoots were individualized and then inoculated in 10 litres temporary immersion system (TIS containing 3 litres of the same basal MS liquid medium. The effects of three immersion frequency (immersion every 12, 6 and 4 hours on the production of biomass were studied. Three inoculum densities (forty, fifty and sixty shoots/TIS were also tested. The biomass growth was inûuenced by the immersion frequency. The highest proliferation rate (17.3 shoots/explants and the plant length (45.2 cm were obtained in plants immersed every 4 h. Also, the fresh and dry biomass weight (153.4 gFW and 24.8 gDW, respectively were higher in this treatment. The maximum biomass accumulation (185.2 gFW and 35.2 gDW was achieved after 30 days of culture when an inoculum density of 60 explants per TIS was used. For the first time, biomass of C. citratus has been produced in10 litres TIS. These results represent the first step in the scaling-up the biomass production of this medicinal plant in large temporary immersion bioreactors. Key words: automation, biomass growth, lemmon grass medicinal plant, tissue culture

  3. Verification of Scaling Relationship Between Litter Production and Biomass in a Near Tropical Montane Cloud Forest

    Science.gov (United States)

    Hu, K. T.; Huang, C.; Yuan, S. C.; Tai, T. C.

    2016-12-01

    Litterfall plays a crucial role in the carbon and nutrient cycles of forest ecosystems. The amount of litterfall governs the amount of carbon and nutrient to be returned in a forest ecosystem. However, when it comes to quantify forest litterfall, collection of canopy characteristic parameters for existing litterfall models is usually time-consuming and labor-intensive. Recent studies indicated that, in metabolic scaling theory, there is a common relationship between terrestrial plant production and biomass; a major part of the production is contributed by litterfall. Therefore, there could be a relationship between litterfall and biomass, which could facilitate large spatial scale estimation of litterfall since biomass may be assessed using remote sensing. To investigate this relationship, we acquired monthly litterfall of a hinoki (Chamaecyparis spp.) dominant montane forest in the northeastern Taiwan (23.98 N, 120.97 E) across the elevation range of 1267-2080 m a.s.l. Monthly litterfall data were recorded from fifteen 0.09 ha plots and each plot consisted from four randomly arranged 0.5 m2 litterfall traps. In addition, diameter at breast height of each live hinoki trees (n = 1,129) within all plots were measured and total biomass was derived using an in-situ species-specific allometry. We found that the relationship between biomass and litterfall might depend on season. Significant concordance between the ranking of tree size and litter production of different sites (Spearman's rank correlation, rho = 0.60, p = 0.0001) could be found as the growing season started. With the aid of fine grain airborne light detection and ranging (LiDAR) data, we may be able to provide a spatial layer of hinoki biomass and map growing season litterfall over a vast region. Furthermore, the study could help increase our understanding of the mechanism governing the litter production and improve future prediction of the ecosystem function.

  4. Biomass combustion gas turbine CHP

    Energy Technology Data Exchange (ETDEWEB)

    Pritchard, D.

    2002-07-01

    This report summarises the results of a project to develop a small scale biomass combustor generating system using a biomass combustor and a micro-gas turbine indirectly fired via a high temperature heat exchanger. Details are given of the specification of commercially available micro-turbines, the manufacture of a biomass converter, the development of a mathematical model to predict the compatibility of the combustor and the heat exchanger with various compressors and turbines, and the utilisation of waste heat for the turbine exhaust.

  5. Gasification and pyrolysis of different biomasses in lab scale system: A comparative study

    Directory of Open Access Journals (Sweden)

    Gądek W.

    2016-01-01

    Full Text Available Gasification and pyrolysis are very promising technologies for clean energy production especially from low rank fuels. Biomass and wastes with high chlorine, alkali and even heavy metals content are fuels preferential for thermal utilization. However, several problems during combustion in conventional steam boilers occurs e.g. slagging, fouling, chlorine corrosion, boiler efficiency deterioration. New efficient and cost effective technologies are needed, even in small-scale applications. The main objective of this work was to compare the thermochemical behaviour and process parameters effects of different biomass under air gasification and pyrolysis conditions. Three important fuels for European power industry were selected: woody biomass and two residual biomass, such as oat straw and dried citrus wastes. In order to evaluate the possibility to use different feedstocks or to combine and/or integrate them in thermochemical processes, a comparison among typical and untypical feedstocks is needed. Tests performed on small scale fixed bed reactor show the gas yield, its composition and LHV parameter. The results were performed in Royal Institute of Technology (KTH in Sweden during BRISK program (Biofuels Research Infrastructure for Sharing Knowledge.

  6. Biohydrogen production from microalgal biomass: energy requirement, CO2 emissions and scale-up scenarios.

    Science.gov (United States)

    Ferreira, Ana F; Ortigueira, Joana; Alves, Luís; Gouveia, Luísa; Moura, Patrícia; Silva, Carla

    2013-09-01

    This paper presents a life cycle inventory of biohydrogen production by Clostridium butyricum through the fermentation of the whole Scenedesmus obliquus biomass. The main purpose of this work was to determine the energy consumption and CO2 emissions during the production of hydrogen. This was accomplished through the fermentation of the microalgal biomass cultivated in an outdoor raceway pond and the preparation of the inoculum and culture media. The scale-up scenarios are discussed aiming for a potential application to a fuel cell hybrid taxi fleet. The H2 yield obtained was 7.3 g H2/kg of S. obliquus dried biomass. The results show that the production of biohydrogen required 71-100 MJ/MJ(H2) and emitted about 5-6 kg CO2/MJ(H2). Other studies and production technologies were taken into account to discuss an eventual process scale-up. Increased production rates of microalgal biomass and biohydrogen are necessary for bioH2 to become competitive with conventional production pathways. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Sensitivities Affecting Heat and Urban Heat Island Effect on Local Scale Projected to Neighborhood Scale in Baltimore, Maryland

    Science.gov (United States)

    Sze, C.; Zaitchik, B. F.; Scott, A.

    2015-12-01

    Urban regions are often impacted more by heat than adjacent rural areas, which is a phenomenon known as the urban heat island (UHI) effect. Urban areas are also highly heterogeneous and notoriously difficult to monitor using standard meteorological protocols—the hottest microclimates within a city often occur in locations that lack open, representative installation sites that are an adequate distance from buildings and direct heat sources. To investigate the challenges of monitoring urban heat, this study examines the sensitivity of temperature and humidity sensors currently used in a Baltimore UHI monitoring network to differences in sun exposure, material on which the data collecting instrument is attached, and land cover class of the vicinity. Sensitivity to sun exposure and attachment site can be interpreted as sources of uncertainty for urban heat monitoring, while sensitivity to land cover may reflect a true source of local temperature and humidity variability. In this study, we present results from a test deployment designed to assess the sensitivity of heat measurements to each of these three factors. We then apply these results to interpret measurements taken across the entire Baltimore UHI monitoring network. These results can then be used to improve heat measurements and more accurately represent and quantify the UHI effect on a broader scale, such as in neighborhoods or urban centers.

  8. Logistics, Costs, and GHG Impacts of Utility-Scale Co-Firing with 20% Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Nichol, Corrie Ian [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-06-01

    This study analyzes the possibility that biopower in the U.S. is a cost-competitive option to significantly reduce greenhouse gas emissions. In 2009, net greenhouse gas (GHG) emitted in the United States was equivalent to 5,618 million metric tons CO2, up 5.6% from 1990 (EPA 2011). Coal-fired power generation accounted for 1,748 million metric tons of this total. Intuitively, life-cycle CO2 emissions in the power sector could be reduced by substituting renewable biomass for coal. If just 20% of the coal combusted in 2009 had been replaced with biomass, CO2 emissions would have been reduced by 350 million metric tons, or about 6% of net annual GHG emission. This would have required approximately 225 million tons of dry biomass. Such an ambitious fuel substitution would require development of a biomass feedstock production and supply system tantamount to coal. This material would need to meet stringent specifications to ensure reliable conveyance to boiler burners, efficient combustion, and no adverse impact on heat transfer surfaces and flue gas cleanup operations. Therefore, this report addresses the potential cost/benefit tradeoffs of co-firing 20% specification-qualified biomass (on an energy content basis) in large U.S. coal-fired power plants. The dependence and sensitivity of feedstock cost on source of material, location, supply distance, and demand pressure was established. Subsequently, the dependence of levelized cost of electricity (LCOE) on feedstock costs, power plant feed system retrofit, and impact on boiler performance was determined. Overall life-cycle assessment (LCA) of greenhouse gas emissions saving were next evaluated and compared to wind and solar energy to benchmark the leading alternatives for meeting renewable portfolio standards (or RPS).

  9. The influence of temperature and heating rate on the slow pyrolysis of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Williams, P.T.; Besler, Serpil [Leeds Univ. (United Kingdom). Dept. of Fuel and Energy

    1996-10-01

    The slow pyrolysis of biomass in the form of pine wood was investigated in a static batch reactor at pyrolysis temperatures from 300 to 720{sup o}C and heating rates from 5 to 80 K min{sup -1}. The compositions and properties of the derived gases, pyrolytic oils and solid char were determined in relation to pyrolysis temperatures and heating rates. In addition, the wood and the major components of the wood - cellulose, hemicellulose and lignin - were pyrolysed in a thermogravimetric analyser (TGA) under the same experimental conditions as in the static batch reactor. The static batch reactor results showed that as the pyrolysis temperature was increased, the percentage mass of solid char decreased, while gas and oil products increased. There was a small effect of heating rate on product yield. The lower temperature regime of decomposition of wood showed that mainly H{sub 2}O, CO{sub 2} and CO were evolved and at the higher temperature regime, the main decomposition products were oil, H{sub 2}O, H{sub 2}, hydrocarbon gases and lower concentrations of CO and CO{sub 2}. Fourier transformation infra-red spectroscopy and elemental analysis of the oils showed they were highly oxygenated. The TGA results for wood showed two main regimes of weight loss, the lower temperature regime could be correlated with the decomposition of hemicellulose and the initial stages of cellulose decomposition whilst the upper temperature regime correlated mainly with the later stages of cellulose decomposition. Lignin thermal decomposition occurred throughout the temperature range of pyrolysis. (author)

  10. Liquid transportation fuels via large-scale fluidised-bed gasification of lignocellulosic biomass

    Energy Technology Data Exchange (ETDEWEB)

    Hannula, I.; Kurkela, E.

    2013-04-15

    With the objective of gaining a better understanding of the system design trade-offs and economics that pertain to biomass-to-liquids processes, 20 individual BTL plant designs were evaluated based on their technical and economic performance. The investigation was focused on gasification-based processes that enable the conversion of biomass to methanol, dimethyl ether, Fischer-Tropsch liquids or synthetic gasoline at a large (300 MWth of biomass) scale. The biomass conversion technology was based on pressurised steam/O2-blown fluidised-bed gasification, followed by hot-gas filtration and catalytic conversion of hydrocarbons and tars. This technology has seen extensive development and demonstration activities in Finland during the recent years and newly generated experimental data has also been used in our simulation models. Our study included conceptual design issues, process descriptions, mass and energy balances and production cost estimates. Several studies exist that discuss the overall efficiency and economics of biomass conversion to transportation liquids, but very few studies have presented a detailed comparison between various syntheses using consistent process designs and uniform cost database. In addition, no studies exist that examine and compare BTL plant designs using the same front-end configuration as described in this work. Our analysis shows that it is possible to produce sustainable low-carbon fuels from lignocellulosic biomass with first-law efficiency in the range of 49.6-66.7% depending on the end-product and process conditions. Production cost estimates were calculated assuming Nth plant economics and without public investment support, CO2 credits or tax assumptions. They are 58-65 euro/MWh for methanol, 58-66 euro/MWh for DME, 64-75 euro/MWh for Fischer-Tropsch liquids and 68-78 euro/MWh for synthetic gasoline. (orig.)

  11. Studying the melting behavior of coal, biomass, and coal/biomass ash using viscosity and heated stage XRD data

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Folkedahl, B.; Dam-Johansen, Kim

    2006-01-01

    by the cocombustion tests appeared to be somewhat different compared to that of the laboratory-prepared ash samples. The heated stage XRD data provide useful information regarding the reactions among the various ash compounds and the phase transformations during the heating and cooling of the ash samples and helped...... the explanation of the produced viscosity curves....

  12. Particulate emissions from biomass combustion in small district heating plants; Partikelemissioner fraan biobraensleeldade mindre fjaerrvaermecentraler

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Henrik; Johansson, Linda; Tullin, Claes; Oesterberg, Stefan; Johansson, Mathias [Swedish National Testing and Research Inst., Boraas (Sweden); Leckner, Bo [Chalmers Univ. of Technology, Goeteborg (Sweden). Energy Conversion

    2001-12-01

    In recent years, negative health effects associated with increased levels of PM{sub 10} and PM{sub 2.5} (particles less then 10 and 2.5 {mu}m, respectively) in the ambient air have been highlighted. The development towards a sustainable society will lead to an increased use of biomass in Sweden. Conversion from oil to biomass can lead to increased local levels of particulate matter. In smaller district heating plants (up to a few MW), the dust reduction often is restricted to the use of cyclones/multicyclones having limited separation efficiency for submicron particles (particles less than 1 {mu}m). The emissions are often in the range 100 Mg/nm{sup 3} or higher but very few data regarding particle size distributions from district heating plants have been reported in the literature. In addition to the particle size, a number of other properties might be important for the health effects but the knowledge in this area is limited. It is therefore important to characterise the particles in detail regarding physical and chemical qualities. The objective with the present investigation is to measure and characterise the particulate emissions from two biomass based smaller district heating centrals for different fuel qualities (pellets, briquettes, forest residues and wood chips) and operating parameters such as load and excess air. In addition to analyses of dust and particulates, extensive measurements of the flue composition have been performed. Measurements were performed downstream the multicyclones. The dust emissions were found to be in the range 20 to 120 mg/MJ supplied fuel depending on operating condition and fuel quality. At normal operation, the dust emissions were about 35 to 40 mg/MJ supplied fuel. The particle size distributions were measured using an ELPI (Electric Low Pressure Impactor). The number size distributions were found to be dominated by submicron particles with maxima at diameters between 0. 1 and 0.3 gm. Additional measurements indicated that

  13. A Co-Powered Biomass and Concentrated Solar Power Rankine Cycle Concept for Small Size Combined Heat and Power Generation

    Directory of Open Access Journals (Sweden)

    Eileen Tortora

    2013-03-01

    Full Text Available The present work investigates the matching of an advanced small scale Combined Heat and Power (CHP Rankine cycle plant with end-user thermal and electric load. The power plant consists of a concentrated solar power field co-powered by a biomass furnace to produce steam in a Rankine cycle, with a CHP configuration. A hotel was selected as the end user due to its high thermal to electric consumption ratio. The power plant design and its operation were modelled and investigated by adopting transient simulations with an hourly distribution. The study of the load matching of the proposed renewable power technology and the final user has been carried out by comparing two different load tracking scenarios, i.e., the thermal and the electric demands. As a result, the power output follows fairly well the given load curves, supplying, on a selected winter day, about 50 GJ/d of thermal energy and the 6 GJ/d of electric energy, with reduced energy dumps when matching the load.

  14. Effect of materials mixture on the higher heating value: Case of biomass, biochar and municipal solid waste.

    Science.gov (United States)

    Boumanchar, Imane; Chhiti, Younes; M'hamdi Alaoui, Fatima Ezzahrae; El Ouinani, Amal; Sahibed-Dine, Abdelaziz; Bentiss, Fouad; Jama, Charafeddine; Bensitel, Mohammed

    2017-03-01

    The heating value describes the energy content of any fuel. In this study, this parameter was evaluated for different abundant materials in Morocco (two types of biochar, plastic, synthetic rubber, and cardboard as municipal solid waste (MSW), and various types of biomass). Before the evaluation of their higher heating value (HHV) by a calorimeter device, the thermal behavior of these materials was investigated using thermogravimetric (TGA) and Differential scanning calorimetry (DSC) analyses. The focus of this work is to evaluate the calorific value of each material alone in a first time, then to compare the experimental and theoretical HHV of their mixtures in a second time. The heating value of lignocellulosic materials was between 12.16 and 20.53MJ/kg, 27.39 for biochar 1, 32.60MJ/kg for biochar 2, 37.81 and 38.00MJ/kg for plastic and synthetic rubber respectively and 13.81MJ/kg for cardboard. A significant difference was observed between the measured and estimated HHVs of mixtures. Experimentally, results for a large variety of mixture between biomass/biochar and biomass/MSW have shown that the interaction between biomass and other compounds expressed a synergy of 2.37% for biochar 1 and 6.11% for biochar 2, 1.09% for cardboard, 5.09% for plastic and 5.01% for synthetic rubber. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Evaluation of scale formation in waterwall heated surfaces

    Directory of Open Access Journals (Sweden)

    Taylasheva Tatiana

    2017-01-01

    Full Text Available This paper presents the possibility of forecasting assessments of the speed and the time of formation of depositions in the evaporator-tube elements of double-drum boilers. The values of thermal flow in the wall region of tank screens of boiler furnace are obtained, besides the velocity values of scaling metal corrosion products are obtained. Conclusions about the ability of forecasting unnominal situations and emergency risks dependent with damage to the screen surface heating pipes are made.

  16. Backshell Radiative Heating on Human-Scale Mars Entry Vehicles

    Science.gov (United States)

    West,Thomas K., IV; Theisinger, John E.; Brune, Andrew J.; Johnston, Christopher O.

    2017-01-01

    This work quantifies the backshell radiative heating experienced by payloads on human- scale vehicles entering the Martian atmosphere. Three underlying configurations were studied: a generic sphere, a sphere-cone forebody with a cylindrical payload, and an ellipsled. Computational fluid dynamics simulations of the flow field and radiation were performed using the LAURA and HARA codes, respectively. Results of this work indicated the primary contributor to radiative heating is emission from the CO2 IR band system. Furthermore, the backshell radiation component of heating can persist lower than 2 km/s during entry and descent. For the sphere-cone configuration a peak heat flux of about 3.5 W/cm(exp. 2) was observed at the payload juncture during entry. At similar conditions, the ellipsled geometry experienced about 1.25 W/cm(exp. 2) on the backshell, but as much as 8 W/cm(exp. 2) on the base at very high angle of attack. Overall, this study sheds light on the potential magnitudes of backshell radiative heating that various configurations may experience. These results may serve as a starting point for thermal protection system design or configuration changes necessary to accommodate thermal radiation levels.

  17. Foliage and Grass as Fuel Pellets–Small Scale Combustion of Washed and Mechanically Leached Biomass

    Directory of Open Access Journals (Sweden)

    Jan Hari Arti Khalsa

    2016-05-01

    Full Text Available The high contents of disadvantageous elements contained in non-woody biomass are known to cause problems during small and large scale combustion, typically resulting in a higher risk of slagging, corrosion, and increased emissions. Mechanically leaching the respective elements from the biomass through a sequence of process steps has proven to be a promising solution.The florafuel process used here is comprised of size reduction followed by washing and subsequent mechanical dewatering of the biomass. Densification of the upgraded biomass into standardized pellets (Ø 6mm enables an application in existing small-scale boilers. The presented combustion trials investigated the performance of pellets made from leached grass, foliage and a mixture of both in two small-scale boilers (<100 kWth with slightly different technology (moving grate versus water-cooled burner tube during a 4-h measurement period. Emissions were in accordance with German emissions standards except for NOx (threshold is 0.50 g/m3 in the case of pure grass pellets (0.51 g/m3 and particulate matter (PM in all but one case (foliage, 13–16 mg/m3. An electrostatic precipitator (ESP unit installed with one of the boilers successfully reduced PM emission of both the grass and mixture fuel below the threshold of 20 mg/m3 (all emission values refer to 13 vol.% O2, at standard temperature and pressure (STP. Bottom ash composition and grate temperature profiles were analyzed and discussed for one of the boilers.

  18. Biomass Suspension Combustion: Effect of Two-Stage Combustion on NOx Emissions in a Laboratory-Scale Swirl Burner

    DEFF Research Database (Denmark)

    Lin, Weigang; Jensen, Peter Arendt; Jensen, Anker Degn

    2009-01-01

    A systematic study was performed in a suspension fired 20 kW laboratory-scale swirl burner test rig for combustion of biomass and co-combustion of natural gas and biomass. The main focus is put on the effect of two-stage combustion on the NO emission, as well as its effect on the incomplete...

  19. The Forest Energy Chain in Tuscany: Economic Feasibility and Environmental Effects of Two Types of Biomass District Heating Plant

    Directory of Open Access Journals (Sweden)

    Claudio Fagarazzi

    2014-09-01

    Full Text Available The purpose of this study was to examine two biomass district heating plants operating in Tuscany, with a specific focus on the ex-post evaluation of their economic and financial feasibility and of their environmental benefits. The former biomass district heating plant supplies only public users (Comunità Montana della Lunigiana, CML: administrative body that coordinates the municipalities located in mountain areas, the latter supplies both public and private users (Municipality of San Romano in Garfagnana. Ex-post investment analysis was performed to check both the consistency of results with the forecasts made in the stage of the project design and on the factors, which may have reduced or jeopardized the estimated economic performance of the investment (ex-ante assessment. The results of the study point out appreciable results only in the case of biomass district heating plants involving private users and fuelled by biomasses sourced from third parties. In this case, the factors that most influence ex-post results include the conditions of the woody biomass local market (market prices, the policies of energy selling prices to private users and the temporal dynamics of private users’ connection. To ensure the consistency of ex-post economic outcome with the expected results it is thus important to: (i have good knowledge of the woody local market; (ii define energy selling prices that should be cheap for private users but consistent with energy production costs and (iii constrain private users beforehand to prevent errors in the plant design and in the preliminary estimate of return on investment. Moreover, the results obtained during the monitoring activities could help in providing information on the effectiveness of the supporting measures adopted and also to orient future choices of policy makers and particularly designers, to identify the most efficient configuration of district heating organization for improving energy and

  20. Time scale dependent negative emission potential of forests and biomass plantations via wood burial, torrefied biomass, biochar and pyrogas condensate sequestration in soil

    Science.gov (United States)

    Schmidt, Hans-Peter; Kammann, Claudia; Lucht, Wolfgang; Gerten, Dieter; Foidl, Nikolaus

    2017-04-01

    The efficiency of Negative Emission Technologies (NET) is dependent on (1) the transformation of the biomass carbon into a form that can be sequestered, (2) the mean residence time of the sequestered carbon, (3) the regrowth and thus carbon re-accumulation of the harvested biomass, and (4) the positive or negative priming of soil carbon. These four parameters define the time scale dependent C-balance of various NET-Systems and permit a global economic and environmental evaluation. As far as geologic CO2 storage is considered to be feasible with close to zero losses and if the energy for transport, transformation and disposal is taken from the process bioenergy, conventional BE-CCS has a C sequestration potential of 50 - 70 % depending on the type of biomass and the technology used. Beside unknown risks of deep stored CO2 and high costs, regrowth of C-accumulating biomass is hampered in the long-term as not only carbon but also essential soil nutrients are mined. Under this scenario, biomass regrowth is expected to slow down and soil carbon content to decrease. These factors enlarge the time horizon until a BE-CCS system becomes carbon neutral and eventual carbon negative (when biomass regrowth exceeds the difference between the harvested biomass carbon and BE-CCS stored carbon). Thermal treatment of biomass under a low oxygen regime (torrefaction, pyrolysis, gasification) can transform up to 85% of biomass carbon into various solid and liquid forms of recalcitrant carbon that can be sequestered. Depending on the process parameters and temperature, the mean residence time of the torrefied or pyrolysed biomass can last from several decennials to centennials when applied to the soil of the biomass production site. The carbon can thus be stored at comparatively low costs within the ecosystem itself. As the thermal treatment preserves most of the biomass-accumulated nutrients (except N), natural nutrient cycles are maintained within the biomass system. Depending on the

  1. Electrodialytic removal of cadmium from biomass combustion fly ash in larger scale

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

    2005-01-01

    Due to a high concentration of the toxic heavy metal cadmium (Cd), biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. It has previously been shown that it is possible to reduce the concentration of Cd in different bio ashes......). The experimental ash was a straw combustion fly ash suspended in water. Within 4 days of remediation, Cd concentrations below the limiting concentration of 5.0 mg Cd/kg DM for straw ash were reached. On the basis of these results, the energy costs for remediation of ash in industrial scale have been estimated...... significantly by using electrodialytic remediation, an electrochemically assisted extraction method. In this work the potential of the method was demonstrated in larger scale. Three different experimental set-ups were used, ranging from bench-scale (25 L ash suspension) to pilot scale (0.3 - 3 m3...

  2. Operating Experiences with a Small-scale CHP Pilot Plant based on a 35 kWel Hermetic Four Cylinder Stirling Engine for Biomass Fuels

    DEFF Research Database (Denmark)

    Biedermann, F.; Carlsen, Henrik; Schoech, M.

    2003-01-01

    Within the scope of the RD&D project presented a small-scale CHP plant with a hermetic four cylinder Stirling engine for biomass fuels was developed and optimised in cooperation with the Technical University of Denmark, MAWERA Holzfeuerungsanlagen GesmbH, an Austrian biomass furnace and boiler ma...... exchanger of the Stirling engine, of the air preheater and of the entire combustion system. Furthermore, the optimisation of the pneumatic cleaning system to reduce ash deposition in the hot heat exchanger is of great relevance.......Within the scope of the RD&D project presented a small-scale CHP plant with a hermetic four cylinder Stirling engine for biomass fuels was developed and optimised in cooperation with the Technical University of Denmark, MAWERA Holzfeuerungsanlagen GesmbH, an Austrian biomass furnace and boiler...... manufacturer, and BIOS BIOENERGIESYSTEME GmbH, an Austrian development and engineering company. Based on the technology developed, a pilot plant was designed and erected in Austria. The nominal electric power output of the plant is 35 kWel and the nominal thermal output amounts to approx. 220 kWth. The plant...

  3. Heat Release Effects on Scaling Laws for Turbulent Shear Flows

    Science.gov (United States)

    Tacina, Kathleen M.; Dahm, Werner J. A.

    1996-11-01

    Experiments have long suggested apparent differences in the fundamental scaling laws for turbulent shear flows between reacting and nonreacting flows. These differences result from the density changes produced by exothermic reaction, and are here shown to be similar to the changes produced by free-stream density differences in nonreacting flows. Motivated by this, we show that the fundamental scaling laws can be generalized to predict the changes due to heat release. The bilinear dependence of temperature T(ζ) on an appropriately defined conserved scalar ζ allows the density changes to be related to an equivalent nonreacting flow, in which one of the free-stream fluid temperatures is set to a value determined by the adiabatic flame temperature and the overall stoichiometry. This scaling principle is applied to turbulent jet diffusion flames, and leads to a generalized scaling variable d^+ for both reacting and nonreacting flows; it effectively extends the momentum diameter d^* of Thring & Newby (1952) and Ricou & Spalding (1961) to reacting flows. The resulting predicted effects of heat release show good agreement with all available data from momentum-dominated jet flames. (Supported by GRI Contract No. 5093-260-2728.)

  4. Heating with Biomass in the United Kingdom: Lessons from New Zealand

    Science.gov (United States)

    Mitchell, E. J. S.; Coulson, G.; Butt, E. W.; Forster, P. M.; Jones, J. M.; Williams, A.

    2017-03-01

    In this study we review the current status of residential solid fuel (RSF) use in the UK and compare it with New Zealand, which has had severe wintertime air quality issues for many years that is directly attributable to domestic wood burning in heating stoves. Results showed that RSF contributed to more than 40 μg m-3 PM10 and 10 μg m-3 BC in some suburban locations of New Zealand in 2006, with significant air quality and climate impacts. Models predict RSF consumption in New Zealand to decrease slightly from 7 PJ to 6 PJ between 1990 and 2030, whereas consumption in the UK increases by a factor of 14. Emissions are highest from heating stoves and fireplaces, and their calculated contribution to radiative forcing in the UK increases by 23% between 2010 and 2030, with black carbon accounting for more than three quarters of the total warming effect. By 2030, the residential sector accounts for 44% of total BC emissions in the UK and far exceeds emissions from the traffic sector. Finally, a unique bottom-up emissions inventory was produced for both countries using the latest national survey and census data for the year 2013/14. Fuel- and technology-specific emissions factors were compared between multiple inventories including GAINS, the IPCC, the EMEP/EEA and the NAEI. In the UK, it was found that wood consumption in stoves was within 30% of the GAINS inventory, but consumption in fireplaces was substantially higher and fossil fuel consumption is more than twice the GAINS estimate. As a result, emissions were generally a factor of 2-3 higher for biomass and 2-6 higher for coal. In New Zealand, coal and lignite consumption in stoves is within 24% of the GAINS inventory estimate, but wood consumption is more than 7 times the GAINS estimate. As a result, emissions were generally a factor of 1-2 higher for coal and several times higher for wood. The results of this study indicate that emissions from residential heating stoves and fireplaces may be underestimated in

  5. Algorithms to estimate Antarctic sea ice algal biomass from under-ice irradiance spectra at regional scales

    OpenAIRE

    Melbourne-Thomas, Jessica; Meiners, Klaus M.; Mundy, C. J.; Schallenberg, Christina; Tattersall, Katherine L.; Dieckmann, Gerhard S.

    2015-01-01

    The presence of algal pigments in sea ice alters under-ice irradiance spectra, and the relationship between these variables can be used as a non-invasive means for estimating ice- associated algal biomass on ecologically relevant spatial and temporal scales. While the influence of snow cover and ice algal biomass on spectra transmitted through the snow-ice matrix has been examined for the Arctic, it has not been tested for Antarctic sea ice at regional scales. We used...

  6. Co-firing of coal with biomass and waste in full-scale suspension-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Johansen, Kim; Frandsen, Flemming J.; Jensen, Peter A.; Jensen, Anker D. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of chemical and Biochemical Engineering

    2013-07-01

    The energy policy in Denmark has for many years focused on lowering the net CO{sub 2} emission from heat and power production by replacing fossil fuels by renewable resources. This has been done by developing dedicated grate-fired boilers for biomass and waste fuels but also by developing coal-based suspension-fired boilers to accept still higher fractions of biomass or waste material as fuels. This last development has been challenging of many reasons, including pre-treatment of fuels, and solving potential emission and operational problems during the simultaneous development of supercritical steam cycles with steam temperatures close to 600 C, providing power efficiencies close to 50% (Hein KRG, Sustainable energy supply and environment protection - strategies, resources and technologies. In: Gupta R, Wall T, Hupa M, Wigley F, Tillman D, Frandsen FJ (eds) Proceedings of international conference on impact of fuel quality on power production and the environment, Banff Conference Centre, Banff, Alberta, Canada, 29 Sept-4 Oct, 2008). For 25 years the CHEC (Combustion and Harmful Emission Control) Research Centre at DTU Chemical Engineering, has attained a leading role in research, supporting power producing industry, plant owners and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools. The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This chapter provides an overview of research activities, aiming at increasing biomass shares during co-firing in suspension, conducted in close collaboration with

  7. Heating-insensitive scale increase caused by convective precipitation

    Science.gov (United States)

    Haerter, Jan; Moseley, Christopher; Berg, Peter

    2017-04-01

    The origin of intense convective extremes and their unusual temperature dependence has recently challenged traditional thermodynamic arguments, based on the Clausius-Clapeyron relation. In a sequence of studies (Lenderink and v. Mejgaard, Nat Geosc, 2008; Berg, Haerter, Moseley, Nat Geosc, 2013; and Moseley, Hohenegger, Berg, Haerter, Nat Geosc, 2016) the argument of convective-type precipitation overcoming the 7%/K increase in extremes by dynamical, rather than thermodynamic, processes has been promoted. How can the role of dynamical processes be approached for precipitating convective cloud? One-phase, non-precipitating Rayleigh-Bénard convection is a classical problem in complex systems science. When a fluid between two horizontal plates is sufficiently heated from below, convective rolls spontaneously form. In shallow, non-precipitating atmospheric convection, rolls are also known to form under specific conditions, with horizontal scales roughly proportional to the boundary layer height. Here we explore within idealized large-eddy simulations, how the scale of convection is modified, when precipitation sets in and intensifies in the course of diurnal solar heating. Before onset of precipitation, Bénard cells with relatively constant diameter form, roughly on the scale of the atmospheric boundary layer. We find that the onset of precipitation then signals an approximately linear (in time) increase in horizontal scale. This scale increase progresses at a speed which is rather insensitive to changes in surface temperature or changes in the rate at which boundary conditions change, hinting at spatial characteristics, rather than temperature, as a possible control on spatial scales of convection. When exploring the depth of spatial correlations, we find that precipitation onset causes a sudden disruption of order and a subsequent complete disintegration of organization —until precipitation eventually ceases. Returning to the initial question of convective

  8. Thermodynamic modeling of small scale biomass gasifiers: Development and assessment of the ''Multi-Box'' approach.

    Science.gov (United States)

    Vakalis, Stergios; Patuzzi, Francesco; Baratieri, Marco

    2016-04-01

    Modeling can be a powerful tool for designing and optimizing gasification systems. Modeling applications for small scale/fixed bed biomass gasifiers have been interesting due to their increased commercial practices. Fixed bed gasifiers are characterized by a wide range of operational conditions and are multi-zoned processes. The reactants are distributed in different phases and the products from each zone influence the following process steps and thus the composition of the final products. The present study aims to improve the conventional 'Black-Box' thermodynamic modeling by means of developing multiple intermediate 'boxes' that calculate two phase (solid-vapor) equilibriums in small scale gasifiers. Therefore the model is named ''Multi-Box''. Experimental data from a small scale gasifier have been used for the validation of the model. The returned results are significantly closer with the actual case study measurements in comparison to single-stage thermodynamic modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Multi-scale sustainability assessments for biomass-based and coal-based fuels in China.

    Science.gov (United States)

    Man, Yi; Xiao, Honghua; Cai, Wei; Yang, Siyu

    2017-12-01

    Transportation liquid fuels production is heavily depend on oil. In recent years, developing biomass based and coal based fuels are regarded as promising alternatives for non-petroleum based fuels in China. With the rapid growth of constructing and planning b biomass based and coal based fuels production projects, sustainability assessments are needed to simultaneously consider the resource, the economic, and the environmental factors. This paper performs multi-scale analyses on the biomass based and coal based fuels in China. The production cost, life cycle cost, and ecological life cycle cost (ELCC) of these synfuels are investigated to compare their pros to cons and reveal the sustainability. The results show that BTL fuels has high production cost. It lacks of economic attractiveness. However, insignificant resource cost and environmental cost lead to a substantially lower ELCC, which may indicate better ecological sustainability. CTL fuels, on the contrary, is lower in production cost and reliable for economic benefit. But its coal consumption and pollutant emissions are both serious, leading to overwhelming resource cost and environmental cost. A shifting from petroleum to CTL fuels could double the ELCC, posing great threat to the sustainability of the entire fuels industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

    Directory of Open Access Journals (Sweden)

    Mazda Biglari

    2016-06-01

    Full Text Available Two modeling approaches, the scaling-law and CFD (Computational Fluid Dynamics approaches, are presented in this paper. To save on experimental cost of the pilot plant, the scaling-law approach as a low-computational-cost method was adopted and a small scale column operating under ambient temperature and pressure was built. A series of laboratory tests and computer simulations were carried out to evaluate the hydrodynamic characteristics of a pilot fluidized-bed biomass gasifier. In the small scale column solids were fluidized. The pressure and other hydrodynamic properties were monitored for the validation of the scaling-law application. In addition to the scaling-law modeling method, the CFD approach was presented to simulate the gas-particle system in the small column. 2D CFD models were developed to simulate the hydrodynamic regime. The simulation results were validated with the experimental data from the small column. It was proved that the CFD model was able to accurately predict the hydrodynamics of the small column. The outcomes of this research present both the scaling law with the lower computational cost and the CFD modeling as a more robust method to suit various needs for the design of fluidized-bed gasifiers.

  11. Mapping Aboveground Biomass in the Amazon Basin: Exploring Sensors, Scales, and Strategies for Optimal Data Linkage

    Science.gov (United States)

    Walker, W. S.; Baccini, A.

    2013-05-01

    Information on the distribution and density of carbon in tropical forests is critical to decision-making on a host of globally significant issues ranging from climate stabilization and biodiversity conservation to poverty reduction and human health. Encouraged by recent progress at both the international and jurisdictional levels on the design of incentive-based policy mechanisms to compensate tropical nations for maintaining their forests intact, governments throughout the tropics are moving with urgency to implement robust national and sub-national forest monitoring systems for operationally tracking and reporting on changes in forest cover and associated carbon stocks. Monitoring systems will be required to produce results that are accurate, consistent, complete, transparent, and comparable at sub-national to pantropical scales, and satellite-based remote sensing supported by field observations is widely-accepted as the most objective and cost-effective solution. The effectiveness of any system for large-area forest monitoring will necessarily depend on the capacity of current and near-future Earth observation satellites to provide information that meets the requirements of developing monitoring protocols. However, important questions remain regarding the role that spatially explicit maps of aboveground biomass and carbon can play in IPCC-compliant forest monitoring systems, with the majority of these questions stemming from doubts about the inherit sensitivity of satellite data to aboveground forest biomass, confusion about the relationship between accuracy and resolution, and a general lack of guidance on optimal strategies for linking field reference and remote sensing data sources. Here we demonstrate the ability of a state-of-the-art satellite radar sensor, the Japanese ALOS/PALSAR, and a venerable optical platform, Landsat 5, to support large-area mapping of aboveground tropical woody biomass across a 153,000-km2 region in the southwestern Amazon

  12. Industrial scale chromatographic separation of valuable compounds from biomass hydrolysates and side streams

    Energy Technology Data Exchange (ETDEWEB)

    Saari, P.

    2011-06-15

    Carbohydrates are composed of a number of various monosaccharides, glucose being the most abundant. Some of the monosaccharides are valuable compounds used in the food and pharmaceutical industries. They can be separated from biomass hydrolysates e.g. by chromatographic methods. In this thesis, chromatographic separation of valuable compounds using ion exchange resins was studied on an industrial scale. Of special interest were rare monosaccharides in biomass hydrolysates. A novel chromatographic separation process was developed for fucose, starting from pre-processed spent sulfite liquor. The core of the process consists of three chromatographic separations with different types of ion exchange resins. Chromatographic separation of galactose was tested with three biomass hydrolysates; lactose, gum arabic and hemicellulose hydrolysates. It was demonstrated that also galactose can be separated from complex carbohydrate mixtures. A recovery process for arabinose from citrus pectin liquid residual and for mannose from wood pulp hydrolysate were also developed and experimentally verified. In addition to monosaccharides, chromatographic separation of glycinebetaine from vinasse was examined with a hydrogen form weak acid cation exchange resin. The separation involves untypical peak formation depending, for example, on the pH and the cation composition. The retention mechanism was found to be hydrogen bonding between glycinebetaine and the resin. In the experimental part, all four resin types - strong acid cation, strong base anion, weak acid cation and weak base anion exchange resins - were used. In addition, adsorption equilibria data of seven monosaccharides and sucrose were measured with the resins in sodium and sulfate forms because such data have been lacking. It was found out that the isotherms of all sugars were linear under industrial conditions. A systematic method for conceptual process design and sequencing of chromatographic separation steps were developed

  13. Modeling and analysis of renewable heat integration into non-domestic buildings - the case of biomass boilers: A whole life asset-supply chain management approach

    OpenAIRE

    Nasiri, Fuzhan; Mafakheri, Fereshteh; Adebanjo, Dotun; Haghighat, Fariborz

    2016-01-01

    This study proposes a whole life asset-supply chain optimization model for integration of biomass boilers into non-domestic (non-residential) buildings, under a renewable heat incentive scheme in the UK. The proposed model aims at identifying the optimal energy generation capacities and schedules for biomass and backup boilers, along with the optimal levels of biomass ordering and storage. The sensitivity of these decisions are then analyzed subject to changes in source, types and pricing of ...

  14. Large scale solar district heating. Evaluation, modelling and designing

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the tool for design studies and on a local energy planning case. The evaluation of the central solar heating technology is based on measurements on the case plant in Marstal, Denmark, and on published and unpublished data for other, mainly Danish, CSDHP plants. Evaluations on the thermal, economical and environmental performances are reported, based on the experiences from the last decade. The measurements from the Marstal case are analysed, experiences extracted and minor improvements to the plant design proposed. For the detailed designing and energy planning of CSDHPs, a computer simulation model is developed and validated on the measurements from the Marstal case. The final model is then generalised to a 'generic' model for CSDHPs in general. The meteorological reference data, Danish Reference Year, is applied to find the mean performance for the plant designs. To find the expectable variety of the thermal performance of such plants, a method is proposed where data from a year with poor solar irradiation and a year with strong solar irradiation are applied. Equipped with a simulation tool design studies are carried out spreading from parameter analysis over energy planning for a new settlement to a proposal for the combination of plane solar collectors with high performance solar collectors, exemplified by a trough solar collector. The methodology of utilising computer simulation proved to be a cheap and relevant tool in the design of future solar heating plants. The thesis also exposed the demand for developing computer models for the more advanced solar collector designs and especially for the control operation of CSHPs. In the final chapter the CSHP technology is put into perspective with respect to other possible technologies to find the relevance of the application

  15. The scale of transition: an integrated study of the performance of CHP biomass plants in the Netherlands

    NARCIS (Netherlands)

    Proka, A.; Hisschemoller, M.; Papyrakis, E.

    2014-01-01

    Combined heat and power (CHP) plants using biomass are considered important to substantially increase the share of renewables in the total energy supply and meet ambitious climate targets. The analysis focuses on the links between the size of bio-fuelled CHP plants and their techno-economic and

  16. Impact assessment of biomass-based district heating systems in densely populated communities. Part II: Would the replacement of fossil fuels improve ambient air quality and human health?

    Science.gov (United States)

    Petrov, Olga; Bi, Xiaotao; Lau, Anthony

    2017-07-01

    To determine if replacing fossil fuel combustion with biomass gasification would impact air quality, we evaluated the impact of a small-scale biomass gasification plant (BRDF) at a university campus over 5 scenarios. The overall incremental contribution of fine particles (PM2.5) is found to be at least one order of magnitude lower than the provincial air quality objectives. The maximum PM2.5 emission from the natural gas fueled power house (PH) could adversely add to the already high background concentration levels. Nitrogen dioxide (NO2) emissions from the BRDF with no engineered pollution controls for NOx in place exceeded the provincial objective in all seasons except during summer. The impact score, IS, was the highest for NO2 (677 Disability Adjusted Life Years, DALY) when biomass entirely replaced fossil fuels, and the highest for PM2.5 (64 DALY) and CO (3 DALY) if all energy was produced by natural gas at PH. Complete replacement of fossil fuels by one biomass plant can result in almost 28% higher health impacts (708 DALY) compared to 513 DALY when both the current BRDF and the PH are operational mostly due to uncontrolled NO2 emissions. Observations from this study inform academic community, city planners, policy makers and technology developers on the impacts of community district heating systems and possible mitigation strategies: a) community energy demand could be met either by splitting emissions into more than one source at different locations and different fuel types or by a single source with the least-impact-based location selection criteria with biomass as a fuel; b) advanced high-efficiency pollution control devices are essential to lower emissions for emission sources located in a densely populated community; c) a spatial and temporal impact assessment should be performed in developing bioenergy-based district heating systems, in which the capital and operational costs should be balanced with not only the benefit to greenhouse gas emission

  17. CFD-supported development of small-scale biomass furnaces; CFD-gestuetzte Entwicklung von Biomassefeuerungen im kleinen Leistungsbereich

    Energy Technology Data Exchange (ETDEWEB)

    Scharler, R. [Bios Bioenergiesystem GmbH, Graz (Austria); Obernberger, I. [Technische Univ. Eindhoven (Netherlands). Thermochemische Biomassekonversion; Weissinger, A. [Oesterreichische Kraft und Waerme aus Biomasse GmbH (KWB), St. Margarethen/Raab (Austria). Bereich Forschung und Entwicklung; Schmidt, W. [Oesterreichische Kraft und Waerme aus Biomasse GmbH (KWB), St. Margarethen/Raab (Austria). Bereich Produktentwicklung, Umwelt- und Informationsmanagement

    2005-07-01

    Despite the complexity of solid biomass combustion, the Bios Bioenergiesysteme GmbH, Graz, Austria, has successfully developed and optimised several biomass furnaces in the range of 500 kW to 30 MW based on CFD (Computational Fluid Dynamics). A project carried out in co-operation with the KWB Kraft und Waerme aus Biomasse GmbH, St. Margarethen, Austria, demonstrates the application of CFD for the efficient and improved design of small-scale furnaces for solid biofuels like pellets and wood chips as basis for a series production. (orig.)

  18. A pilot study of traditional indoor biomass cooking and heating in rural Bhutan: gas and particle concentrations and emission rates.

    Science.gov (United States)

    Wangchuk, T; He, C; Knibbs, L D; Mazaheri, M; Morawska, L

    2017-01-01

    Although many studies have reported the health effects of biomass fuels in developing countries, relatively few have quantitatively characterized emissions from biomass stoves during cooking and heating. The aim of this pilot study was to characterize the emission characteristics of different biomass stoves in four rural houses in Bhutan during heating (metal chimney stove), rice cooking (traditional mud stove), fodder preparation (stone tripod stove), and liquor distillation (traditional mud stove). Three stage measurements (before, during, and after the activity had ceased) were conducted for PM2.5 , particle number (PN), CO, and CO2 . When stoves were operated, the pollutant concentrations were significantly elevated above background levels, by an average of 40 and 18 times for PM2.5 and CO, respectively. Emission rates (mg/min) ranged from 1.07 × 102 (PM2.5 ) and 3.50 × 102 (CO) for the stone tripod stove during fodder preparation to 6.20 × 102 (PM2.5 ) and 2.22 × 103 (CO) for the traditional mud stove during liquor distillation. Usable PN data were only available for one house, during heating using a metal chimney stove, which presented an emission rate of 3.24 × 1013 particles/min. Interventions to control household air pollution in Bhutan, in order to reduce the health risks associated with cooking and heating, are recommended. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Experiences from measurements on combined solar heating and biomass-fired boilers; Erfaringer fra maalinger paa kombinerede solvarme- og biobraendselsanlaeg

    Energy Technology Data Exchange (ETDEWEB)

    Overgaard, L.L.; Ellehauge, K.; Saebye, A.

    2000-05-01

    The 12 inspected Danish systems represent both well-designed and well-functioning small Solar and Biomass systems as well as poor system designs. Some of the faults experienced were oversized and undersized components and insufficient insulation. Also, there were several examples of stop-gab solutions resulting in very complicated systems with a lot of piping connections, great heat losses and a great risk of making operation mistakes. Monitoring of three of the systems over a period of almost a year have shown great differences with regard to operation conditions, heat losses from installations, solar contributions, solar gains as well as number of days the biomass boilers can be turned of each year. In general the solar gains of the three systems were not very large. Generally, there is a need for better overall solutions with components adjusted to the actual demands and boundary conditions. As a part of the project such a new system with one storage tank only has been developed - inspired by already gained experience. The work carried out in this project is the first step on the way to better Solar and Biomass system designs in Denmark, but there is still a lot of work to be done. (EHS)

  20. Local discrepancies in continental scale biomass maps: a case study over forested and non-forested landscapes in Maryland, USA

    Science.gov (United States)

    Wenli Huang; Anu Swatantran; Kristofer Johnson; Laura Duncanson; Hao Tang; Jarlath O' Neil Dunne; George Hurtt; Ralph. Dubayah

    2015-01-01

    Continental-scale aboveground biomass maps are increasingly available, but their estimates vary widely, particularly at high resolution. A comprehensive understanding of map discrepancies is required to improve their effectiveness in carbon accounting and local decision-making. To this end, we compare four continental-scale maps with a recent high-resolution lidar-...

  1. The Price of Precision: Large-Scale Mapping of Forest Structure and Biomass Using Airborne Lidar

    Science.gov (United States)

    Dubayah, R.

    2015-12-01

    Lidar remote sensing provides one of the best means for acquiring detailed information on forest structure. However, its application over large areas has been limited largely because of its expense. Nonetheless, extant data exist over many states in the U.S., funded largely by state and federal consortia and mainly for infrastructure, emergency response, flood plain and coastal mapping. These lidar data are almost always acquired in leaf-off seasons, and until recently, usually with low point count densities. Even with these limitations, they provide unprecedented wall-to-wall mappings that enable development of appropriate methodologies for large-scale deployment of lidar. In this talk we summarize our research and lessons learned in deriving forest structure over regional areas as part of NASA's Carbon Monitoring System (CMS). We focus on two areas: the entire state of Maryland and Sonoma County, California. The Maryland effort used low density, leaf-off data acquired by each county in varying epochs, while the on-going Sonoma work employs state-of-the-art, high density, wall-to-wall, leaf-on lidar data. In each area we combine these lidar coverages with high-resolution multispectral imagery from the National Agricultural Imagery Program (NAIP) and in situ plot data to produce maps of canopy height, tree cover and biomass, and compare our results against FIA plot data and national biomass maps. Our work demonstrates that large-scale mapping of forest structure at high spatial resolution is achievable but products may be complex to produce and validate over large areas. Furthermore, fundamental issues involving statistical approaches, plot types and sizes, geolocation, modeling scales, allometry, and even the definitions of "forest" and "non-forest" must be approached carefully. Ultimately, determining the "price of precision", that is, does the value of wall-to-wall forest structure data justify their expense, should consider not only carbon market applications

  2. Improved prediction of higher heating value of biomass using an artificial neural network model based on proximate analysis.

    Science.gov (United States)

    Uzun, Harun; Yıldız, Zeynep; Goldfarb, Jillian L; Ceylan, Selim

    2017-06-01

    As biomass becomes more integrated into our energy feedstocks, the ability to predict its combustion enthalpies from routine data such as carbon, ash, and moisture content enables rapid decisions about utilization. The present work constructs a novel artificial neural network model with a 3-3-1 tangent sigmoid architecture to predict biomasses' higher heating values from only their proximate analyses, requiring minimal specificity as compared to models based on elemental composition. The model presented has a considerably higher correlation coefficient (0.963) and lower root mean square (0.375), mean absolute (0.328), and mean bias errors (0.010) than other models presented in the literature which, at least when applied to the present data set, tend to under-predict the combustion enthalpy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Particle size distributions from laboratory-scale biomass fires using fast response instruments

    Directory of Open Access Journals (Sweden)

    S. Hosseini

    2010-08-01

    Full Text Available Particle size distribution from biomass combustion is an important parameter as it affects air quality, climate modelling and health effects. To date, particle size distributions reported from prior studies vary not only due to difference in fuels but also difference in experimental conditions. This study aims to report characteristics of particle size distributions in well controlled repeatable lab scale biomass fires for southwestern United States fuels with focus on chaparral. The combustion laboratory at the United States Department of Agriculture-Forest Service's Fire Science Laboratory (USDA-FSL, Missoula, MT provided a repeatable combustion and dilution environment ideal for measurements. For a variety of fuels tested the major mode of particle size distribution was in the range of 29 to 52 nm, which is attributable to dilution of the fresh smoke. Comparing mass size distribution from FMPS and APS measurement 51–68% of particle mass was attributable to the particles ranging from 0.5 to 10 μm for PM10. Geometric mean diameter rapidly increased during flaming and gradually decreased during mixed and smoldering phase combustion. Most fuels produced a unimodal distribution during flaming phase and strong biomodal distribution during smoldering phase. The mode of combustion (flaming, mixed and smoldering could be better distinguished using the slopes in MCE (Modified Combustion Efficiency vs. geometric mean diameter than only using MCE values.

  4. Self-heating co-pyrolysis of excessive activated sludge with waste biomass: energy balance and sludge reduction.

    Science.gov (United States)

    Ding, Hong-Sheng; Jiang, Hong

    2013-04-01

    In this work, co-pyrolysis of sludge with sawdust or rice husk was investigated. The results showed that the co-pyrolysis technology could be used to dispose of the excessive activated sludge without external energy input. The results also demonstrated that no obvious synergistic effect occurred except for heat transfer in the co-pyrolysis if the co-feeding biomass and sludge had similar thermogravimetric characteristics. The experimental results combined with calculation showed that adding sawdust accounting for 49.6% of the total feedstock or rice husk accounting for 74.7% could produce bio-oil to keep the energy balance of the co-pyrolysis system and self-heat it. The sludge from solar drying bed can be further reduced by 38.6% and 35.1% by weight when co-pyrolyzed with rice husk and sawdust, respectively. This study indicates that sludge reduction without external heat supply through co-pyrolysis of sludge with waste biomass is practically feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. A heat wave and dispersal cause dominance shift and decrease biomass in experimental metacommunities

    NARCIS (Netherlands)

    Eggers, Sarah Lena; Eriksson, Britas Klemens; Matthiessen, Birte

    In experimental metacommunities with marine benthic microalgae, we tested whether heat stress changes effects of connectivity and habitat heterogeneity on metacommunity structure and functioning, by manipulating a simulated heat wave, dispersal frequency and a light intensity gradient. We found that

  6. Pilot scale harvesting, separation and drying of microalgae biomass from compact photo-bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Alberto Tadeu Martins; Luz Junior, Luiz Fernando de Lima [Dept. de Engenharia Quimica. Universidade Federal do Parana, Curitiba, PR (Brazil)], e-mail: luzjr@ufpr.br; Mariano, Andre Bellin; Ghidini, Luiz Francisco Correa; Gnoatto, Victor Eduardo; Locatelli Junior, Vilson; Mello, Thiago Carvalho de; Vargas, Jose Viriato Coelho [Nucleo de Pesquisa e Desenvolvimento em Energia Autossustentavel (NPDEAS). Dept. de Engenharia Mecanica. Universidade Federal do Parana, Curitiba (Brazil)], E-mail: jvargas@demec.ufpr.br

    2010-07-01

    Bio diesel produced from microalgae lipids is gaining a substantial ground in the search for renewable energy sources. In order to optimize the operating conditions of a continuous process, several experiments were realized, both in laboratory and pilot scale. The microalgae cultivation can be conducted in a photo-bioreactor, a closed system which allows parameters control and necessarily involves the aquatic environment. Because of that, the use of separation unit operations is required. The process starts in a proposed compact photo-bioreactor, which consist of a chain of transparent tubes with 6 cm of diameter arranged in parallel where the cultivation media circulate with the help of a pump. This arrangement offers a closed culture with less risk of contamination and maintains a minimum contact with the environment. The microalgae grow inside the pipes under incidence of ambient light. In this paper, harvesting, separation and drying were studied, as part of the processes of a sustainable energy plant under construction at UFPR, as shown in Fig. 1. To control the production in a photo-bioreactor in continuous system, it is necessary to monitor the concentration of microalgae growth in suspension. To measure the cell concentration in this equipment, an optic sensor has been developed. The microalgae biomass separation from the culture media is achieved by microalgae flocculation. Several cultivation situations have been tested with different NaOH concentrations, increasing the pH to 10. The system was kept under agitation during the addition by an air pump into the tank. Thereafter the system was maintained static. After a short time, it was observed that the microalgae coagulated and settled. The clarified part water was removed, remaining a concentrated microalgae suspension. Our results suggest that pH increase is a suitable methodology for microalgae separation from the growth suspension. The microalgae sedimentation time was recorded, which allowed the

  7. Fluidized bed gasification for biomass combined heat and power production in Guessing; Biomasse Kraft-Waerme-Kopplung mit Wirbelschichtvergasung. Demonstrationsanlage in Guessing/Oesterreich

    Energy Technology Data Exchange (ETDEWEB)

    Hofbauer, H.; Rauch, R. [Technische Univ., Vienna (Austria). Inst. fuer Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften

    2003-09-01

    In the year 2002 a demonstration plant for combined heat and power production (CHP) from biomass started operation in Guessing (AT), a small city with about 4,000 inhabitants. During the last decade Guessing has changed the energy supply totally to renewable sources. The last plant on this successful way was 8 MW fuel CHP plant based on a steam blown gasifier, a gas cleaning section and production of heat and power(4,5 MW thermal, 2 MW electric) with a gas engine which is able to produce all the electricity consumed in Guessing. A steam blown fluidised bed gasifier was used which produces a nitrogen free gas with a high calorific value (12 MJ/m{sub N}{sup 3}) and only a low amount of tar. A two stage gas cleaning and cooling system make sure that the gas engine gets a cool and clean gas. Until the end of June 2003 about 5,800 hours of operation with the gasifier and 3,600 hours with the gas engine could be reached. The plant shows a very constant and stable operation and fulfil all the requirement from the authorities. No waste water is produced and also the ash show no problems because the ash comes out from a combustor which delivers the heat for the gasification reactions. About 6,000 hours per year are necessary to get economic operation of the plant. (orig.) [German] Im Jahr 2000 wurde in Guessing/Oesterreich ein Biomasseheizkraftwerk auf Basis der Wirbelschichtdampfvergasung errichtet. Die Inbetriebnahme der Vergasungsanlage erfolgte im September 2001; im April 2002 wurde der Gasmotor in Betrieb genommen. Die Ergebnisse der Anlage zeigen, dass der Vergaser wie geplant funktioniert; die Gaszusammensetzung, der Teergehalt des Produktgases und der Wirkungsgrad der Anlage liegen innerhalb des geplanten Bereiches. (orig.)

  8. Emerging trends in small scale biogas plants for agro-residues and biomass feedstocks : a case study from India

    Energy Technology Data Exchange (ETDEWEB)

    Chanakya, H.N. [Indian Inst. of Science, Bangalore (India). Centre for Sustainable Technologies; Moletta, R. [Institut National de la Recherche Agronomique, Narbonne (France). Laboratory for Environmental Biotechnology

    2004-07-01

    This study assessed the performance characteristics of different types of biomass based biogas plants being developed. India has launched a biogas program in rural areas that is based on small scale biogas plants that can function without a need for grid power, process control or a high degree of operating skills. Nearly 4 million units have been built. Studies have been carried out on biogas processes and plant designs that use non-dung biomass as the main feedstock. There has been mixed success with slurry based fermentation and non-dung biomass feedstock. Research programs are focusing on alternative processes to enable operation of simple village-level biogas digester concepts. This study explained the problems encountered during operation in terms of changing physical, chemical and fermentation properties. The results were determined by laboratory studies which quantified the changes in decomposing biomass feedstock. 9 refs., 1 tab., 4 figs.

  9. Contributions to urban heat island on the local neighborhood scale

    Science.gov (United States)

    Hertel, Daniel; Schlink, Uwe

    2017-04-01

    Already today around half of the global population is living in urban regions and recent studies expect a further increase until mid-21st century. Therefore, especially in the context of climate change, an increasing amount of urban inhabitants are affected by urban climate and air quality. One special characteristic of urban climate is the urban heat island (UHI) effect, where urbanized regions are warmer than the rural surroundings. With respect to climate change and the growing urbanization it is obvious that the UHI effect will tend to be intensified. To keep our cities worth living, it is necessary to think about adaptation and mitigation strategies which refer to both, climate protection as well as utilization of chances resulting from climate changes. One step to a more precisely adaptation, particularly on the neighborhood scale, is an improved understanding of the magnitude of bio geophysical processes (e.g.: radiation balance, convection efficiency, evapotranspiration, storage heat, anthropogenic heat etc.), which contribute to the urban warming. Considering that UHI can be expressed as temperature difference ΔT between urban and rural areas, we can interpret these processes as how they would change temperature, because of energy redistribution, from a rural area to an urbanized region. Up to now on the local scale there is a knowledge gap about these processes. The mentioned processes are parts of a surface energy balance (based on the work of Zhao et al., 2014). That means they refer to the surface UHI effect and not to the canopy layer UHI effect. Assuming that the urban region is a volume with the top at the height of the canopy layer, we can approximately identify the surface UHI effect as the canopy layer UHI effect since the information comes from both the surface and the atmosphere inside. This assumption is not valid for Zhao's approach because they analyzed whole cities and could neglect such processes within the volume. This contribution

  10. Testing, development and demonstration of large scale solar district heating systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Fan, Jianhua; Perers, Bengt

    2015-01-01

    In 2013-2014 the project “Testing, development and demonstration of large scale solar district heating systems” was carried out within the Sino-Danish Renewable Energy Development Programme, the so called RED programme jointly developed by the Chinese and Danish governments. In the project Danish...... know how on solar heating plants and solar heating test technology have been transferred from Denmark to China, large solar heating systems have been promoted in China, test capabilities on solar collectors and large scale solar heating systems have been improved in China and Danish-Chinese cooperation...... on solar heating has been improved....

  11. Biosorption of the metal-complex dye Acid Black 172 by live and heat-treated biomass of Pseudomonas sp. strain DY1: Kinetics and sorption mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Du, Lin-Na; Wang, Bing [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China); Li, Gang [Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, 325006 Wenzhou, Zhejiang Province (China); Wang, Sheng [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China); Crowley, David E., E-mail: crowley@ucr.edu [Department of Environmental Science, University of California, Riverside, CA 92521 (United States); Zhao, Yu-Hua, E-mail: yhzhao225@zju.edu.cn [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer The maximum amount of Acid Black 172 sorption was about 2.98 mmol/g biomass. Black-Right-Pointing-Pointer Amine groups played a major role in the biosorption of Acid Black 172. Black-Right-Pointing-Pointer The reasons of increased dye sorption by heat-treated biomass were proposed. - Abstract: The ability of Pseudomonas sp. strain DY1 to adsorb Acid Black 172 was studied to determine the kinetics and mechanisms involved in biosorption of the dye. Kinetic data for adsorption fit a pseudo-second-order model. Increased initial dye concentration could significantly enhance the amount of dye adsorbed by heat-treated biomass in which the maximum amount of dye adsorbed was as high as 2.98 mmol/g biomass, whereas it had no significant influence on dye sorption by live biomass. As treated temperature increased, the biomass showed gradual increase of dye sorption ability. Experiments using potentiometric titration and Fourier transform infrared spectroscopy (FTIR) indicated that amine groups (NH{sub 2}) played a prominent role in biosorption of Acid Black 172. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM) analysis indicated that heat treatment of the biomass increased the permeability of the cell walls and denatured the intracellular proteins. The results of biosorption experiments by different cell components confirmed that intracellular proteins contributed to the increased biosorption of Acid Black 172 by heat-treated biomass. The data suggest that biomass produced by this strain may have application for removal of metal-complex dyes from wastewater streams generated from the dye products industry.

  12. Dynamic modelling of high biomass density cultivation and biohydrogen production in different scales of flat plate photobioreactors.

    Science.gov (United States)

    Zhang, Dongda; Dechatiwongse, Pongsathorn; Del Rio-Chanona, Ehecatl Antonio; Maitland, Geoffrey C; Hellgardt, Klaus; Vassiliadis, Vassilios S

    2015-12-01

    This paper investigates the scaling-up of cyanobacterial biomass cultivation and biohydrogen production from laboratory to industrial scale. Two main aspects are investigated and presented, which to the best of our knowledge have never been addressed, namely the construction of an accurate dynamic model to simulate cyanobacterial photo-heterotrophic growth and biohydrogen production and the prediction of the maximum biomass and hydrogen production in different scales of photobioreactors. To achieve the current goals, experimental data obtained from a laboratory experimental setup are fitted by a dynamic model. Based on the current model, two key original findings are made in this work. First, it is found that selecting low-chlorophyll mutants is an efficient way to increase both biomass concentration and hydrogen production particularly in a large scale photobioreactor. Second, the current work proposes that the width of industrial scale photobioreactors should not exceed 0.20 m for biomass cultivation and 0.05 m for biohydrogen production, as severe light attenuation can be induced in the reactor beyond this threshold. © 2015 Wiley Periodicals, Inc.

  13. Biomass Residues to Renewable Energy: A Life Cycle Perspective Applied at a Local Scale

    Directory of Open Access Journals (Sweden)

    Esmeralda Neri

    2016-11-01

    Full Text Available Italy, like every country member of the European Union (EU, will have to achieve the objectives required by the Energy Roadmap 2050. The purpose of the study was to evaluate the environmental impacts of residue recovery arising from the management of public and private green feedstocks, activity of the cooperative “Green City” in the Bologna district, and usage in a centralized heating system to produce thermal energy for public buildings. Results, obtained using the ReCipe impact assessment method, are compared with scores achieved by a traditional methane boiler. The study shows some advantages of the biomass-based system in terms of greenhouse gases (GHGs emissions and consumption of non-renewable fuels, which affect climate change (−41% and fossil resources depletion (−40%, compared to the use of natural gas (NG. Moreover, scores from network analysis denote the great contribution of feedstock transportation (98% of the cumulative impact. The main reason is attributable to all requirements to cover distances, in particular due to stages involved in the fuel supply chains. Therefore, it is clear that greater environmental benefits could be achieved by reducing supply transport distances or using more sustainable engines.

  14. Microbiological Contamination at Workplaces in a Combined Heat and Power (CHP) Station Processing Plant Biomass.

    Science.gov (United States)

    Szulc, Justyna; Otlewska, Anna; Okrasa, Małgorzata; Majchrzycka, Katarzyna; Sulyok, Michael; Gutarowska, Beata

    2017-01-21

    The aim of the study was to evaluate the microbial contamination at a plant biomass processing thermal power station (CHP). We found 2.42 × 10³ CFU/m³ of bacteria and 1.37 × 10⁴ CFU/m³ of fungi in the air; 2.30 × 10⁷ CFU/g of bacteria and 4.46 × 10⁵ CFU/g of fungi in the biomass; and 1.61 × 10² CFU/cm² bacteria and 2.39 × 10¹ CFU/cm² fungi in filtering facepiece respirators (FFRs). Using culture methods, we found 8 genera of mesophilic bacteria and 7 of fungi in the air; 10 genera each of bacteria and fungi in the biomass; and 2 and 5, respectively, on the FFRs. Metagenomic analysis (Illumina MiSeq) revealed the presence of 46 bacterial and 5 fungal genera on the FFRs, including potential pathogens Candida tropicalis, Escherichia coli, Prevotella sp., Aspergillus sp., Penicillium sp.). The ability of microorganisms to create a biofilm on the FFRs was confirmed using scanning electron microscopy (SEM). We also identified secondary metabolites in the biomass and FFRs, including fumigaclavines, quinocitrinines, sterigmatocistin, and 3-nitropropionic acid, which may be toxic to humans. Due to the presence of potential pathogens and mycotoxins, the level of microbiological contamination at workplaces in CHPs should be monitored.

  15. Sustainability Assessment of a Self-Consumption Wood-Energy Chain on Small Scale for Heat Generation in Central Italy

    Directory of Open Access Journals (Sweden)

    Stefano Verani

    2015-06-01

    Full Text Available The sustainability of a small-scale self-consumption wood-energy chain for heat generation in central Italy was analyzed from a technical, economic and energetic point of view. A micro-chain was developed within the CRA-ING farm at Monterotondo (Rome, Italy: The purpose of this system was to produce biomass for supplying a heating plant within the CRA-ING property as a substitute for diesel fuel. A poplar short rotation coppice, established with clones AF2, AF6 and Monviso, fed the micro-chain. The rotation was biennial. The average plantation production (Mgd.m.·ha−1·year−1 was 10.2, with a maximum of 13.53 for the twin-rows AF2 and a minimum of 8.00 for the single-row Monviso. The economic assessment was based on the Net Present Value (NPV method and the equivalent annuity cost, and found an average saving of 15.60 €·GJ−1 of heat generated by the wood chips heating system in comparison with the diesel heating system over a 10 year lifetime of the thermal power plant. The energy assessment of the poplar plantation, carried out using the Gross Energy Requirements method, reported an energy output/input ratio of 12.3. The energy output/input ratio of the whole micro-chain was 4.5.

  16. Design and Performance Evaluation of a Solar Assisted Heat Pump Dryer Integrated with Biomass Furnace for Red Chilli

    Directory of Open Access Journals (Sweden)

    M. Yahya

    2016-01-01

    Full Text Available The performance of a solar assisted heat pump dryer integrated with biomass furnace has been designed and evaluated for drying red chillies, and drying kinetics of red chillies were evaluated. The red chillies were dried from 22 kg with moisture content of 4.26 db to moisture content of 0.08 db which needed 11 hours, with the average drying chamber temperature, drying chamber relative humidity, and an air mass flow rate of 70.5°C, 10.1%, and 0.124 kg/s, respectively, while the open sun drying needed 62 hours. Compared to open sun drying, this dryer yielded 82% saving in drying time. The drying rate, the specific moisture extraction rate, and thermal efficiency of the dryer were estimated in average to be about 1.57 kg/h, 0.14 kg/kWh, and 9.03%, respectively. Three mathematical models, the Newton, Henderson-Pabis, and Page models, were fitted to the experimental data on red chillies dried by solar assisted heat pump dryer integrated with biomass furnace and open sun drying. The performance of these models was evaluated by comparing the coefficient of determination (R2, mean bias error (MBE, and root mean-square error (RMSE. The Page model gave the best results for representing drying kinetics of red chillies.

  17. 'Oorja' in India: Assessing a large-scale commercial distribution of advanced biomass stoves to households.

    Science.gov (United States)

    Thurber, Mark C; Phadke, Himani; Nagavarapu, Sriniketh; Shrimali, Gireesh; Zerriffi, Hisham

    2014-04-01

    Replacing traditional stoves with advanced alternatives that burn more cleanly has the potential to ameliorate major health problems associated with indoor air pollution in developing countries. With a few exceptions, large government and charitable programs to distribute advanced stoves have not had the desired impact. Commercially-based distributions that seek cost recovery and even profits might plausibly do better, both because they encourage distributors to supply and promote products that people want and because they are based around properly-incentivized supply chains that could more be scalable, sustainable, and replicable. The sale in India of over 400,000 "Oorja" stoves to households from 2006 onwards represents the largest commercially-based distribution of a gasification-type advanced biomass stove. BP's Emerging Consumer Markets (ECM) division and then successor company First Energy sold this stove and the pelletized biomass fuel on which it operates. We assess the success of this effort and the role its commercial aspect played in outcomes using a survey of 998 households in areas of Maharashtra and Karnataka where the stove was sold as well as detailed interviews with BP and First Energy staff. Statistical models based on this data indicate that Oorja purchase rates were significantly influenced by the intensity of Oorja marketing in a region as well as by pre-existing stove mix among households. The highest rate of adoption came from LPG-using households for which Oorja's pelletized biomass fuel reduced costs. Smoke- and health-related messages from Oorja marketing did not significantly influence the purchase decision, although they did appear to affect household perceptions about smoke. By the time of our survey, only 9% of households that purchased Oorja were still using the stove, the result in large part of difficulties First Energy encountered in developing a viable supply chain around low-cost procurement of "agricultural waste" to make

  18. Genome-Scale Model Reveals Metabolic Basis of Biomass Partitioning in a Model Diatom.

    Directory of Open Access Journals (Sweden)

    Jennifer Levering

    Full Text Available Diatoms are eukaryotic microalgae that contain genes from various sources, including bacteria and the secondary endosymbiotic host. Due to this unique combination of genes, diatoms are taxonomically and functionally distinct from other algae and vascular plants and confer novel metabolic capabilities. Based on the genome annotation, we performed a genome-scale metabolic network reconstruction for the marine diatom Phaeodactylum tricornutum. Due to their endosymbiotic origin, diatoms possess a complex chloroplast structure which complicates the prediction of subcellular protein localization. Based on previous work we implemented a pipeline that exploits a series of bioinformatics tools to predict protein localization. The manually curated reconstructed metabolic network iLB1027_lipid accounts for 1,027 genes associated with 4,456 reactions and 2,172 metabolites distributed across six compartments. To constrain the genome-scale model, we determined the organism specific biomass composition in terms of lipids, carbohydrates, and proteins using Fourier transform infrared spectrometry. Our simulations indicate the presence of a yet unknown glutamine-ornithine shunt that could be used to transfer reducing equivalents generated by photosynthesis to the mitochondria. The model reflects the known biochemical composition of P. tricornutum in defined culture conditions and enables metabolic engineering strategies to improve the use of P. tricornutum for biotechnological applications.

  19. Genome-Scale Model Reveals Metabolic Basis of Biomass Partitioning in a Model Diatom.

    Science.gov (United States)

    Levering, Jennifer; Broddrick, Jared; Dupont, Christopher L; Peers, Graham; Beeri, Karen; Mayers, Joshua; Gallina, Alessandra A; Allen, Andrew E; Palsson, Bernhard O; Zengler, Karsten

    2016-01-01

    Diatoms are eukaryotic microalgae that contain genes from various sources, including bacteria and the secondary endosymbiotic host. Due to this unique combination of genes, diatoms are taxonomically and functionally distinct from other algae and vascular plants and confer novel metabolic capabilities. Based on the genome annotation, we performed a genome-scale metabolic network reconstruction for the marine diatom Phaeodactylum tricornutum. Due to their endosymbiotic origin, diatoms possess a complex chloroplast structure which complicates the prediction of subcellular protein localization. Based on previous work we implemented a pipeline that exploits a series of bioinformatics tools to predict protein localization. The manually curated reconstructed metabolic network iLB1027_lipid accounts for 1,027 genes associated with 4,456 reactions and 2,172 metabolites distributed across six compartments. To constrain the genome-scale model, we determined the organism specific biomass composition in terms of lipids, carbohydrates, and proteins using Fourier transform infrared spectrometry. Our simulations indicate the presence of a yet unknown glutamine-ornithine shunt that could be used to transfer reducing equivalents generated by photosynthesis to the mitochondria. The model reflects the known biochemical composition of P. tricornutum in defined culture conditions and enables metabolic engineering strategies to improve the use of P. tricornutum for biotechnological applications.

  20. Hot Gas Conditioning: Recent Progress with Larger-Scale Biomass Gasification Systems; Update and Summary of Recent Progress

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D. J.

    2001-09-01

    As a result of environmental and policy considerations, there is increasing interest in using renewable biomass resources as feedstock for power, fuels, and chemicals and hydrogen. Biomass gasification is seen as an important technology component for expanding the use of biomass. Advanced biomass gasification systems provide clean products that can be used as fuel or synthesis gases in a variety of environmentally friendly processes. Advanced end-use technologies such as gas turbines or synthesis gas systems require high quality gases with narrowly defined specifications. Other systems such as boilers may also have fuel quality requirements, but they will be substantially less demanding. The gas product from biomass gasifiers contains quantities of particulates, tars, and other constituents that may exceed these specified limits. As a result, gas cleaning and conditioning will be required in most systems. Over the past decade, significant research and development activities have been conducted on the topic of gas cleanup and conditioning. This report provides an update of efforts related to large-scale biomass gasification systems and summarizes recent progress. Remaining research and development issues are also summarized.

  1. Nutrient Removal and Biomass Production in an Outdoor Pilot-Scale Phototrophic Biofilm Reactor for Effluent Polishing

    NARCIS (Netherlands)

    Boelee, N.C.; Janssen, M.; Temmink, H.; Shrestha, R.; Buisman, C.J.N.; Wijffels, R.H.

    2014-01-01

    An innovative pilot-scale phototrophic biofilm reactor was evaluated over a 5-month period to determine its capacity to remove nitrogen and phosphorus from Dutch municipal wastewater effluents. The areal biomass production rate ranged between 2.7 and 4.5 g dry weight/m2/day. The areal nitrogen and

  2. The mathematical description of the gasification process of woody biomass in installations with a plasma heat source for producing synthesis gas

    Science.gov (United States)

    Sadrtdinov, A. R.; Safin, R. G.; Gerasimov, M. K.; Petrov, V. I.; Gilfanov, K. K.

    2016-04-01

    The article presents the scheme of processing of plant biomass in the gasification installation with a plasma heat source to produce synthesis gas suitable for chemical industry. The analyzed physical picture of raw materials' recycling process underlies a mathematical description of the process set out in the form of the basic differential equations with boundary conditions. The received mathematical description allows calculating of the main parameters of equipment for biomass recycling and to determine the optimal modes of its operation.

  3. GASEOUS EMISSIONS FROM FOSSIL FUELS AND BIOMASS COMBUSTION IN SMALL HEATING APPLIANCES

    Directory of Open Access Journals (Sweden)

    Daniele Dell'Antonia

    2012-06-01

    Full Text Available The importance of emission control has increased sharply due to the increased need of energy from combustion. However, biomass utilization in energy production is not free from problems because of physical and chemical characteristics which are substantially different from conventional energy sources. In this situation, the quantity and quality of emissions as well as used renewable sources as wood or corn grain are often unknown. To assess this problem the paper addresses the objectives to quantify the amount of greenhouse gases during the combustion of corn as compared to the emissions in fossil combustion (natural gas, LPG and diesel boiler. The test was carried out in Friuli Venezia Giulia in 2006-2008 to determine the air pollution (CO, NO, NO2, NOx, SO2 and CO2 from fuel combustion in family boilers with a power between 20-30 kWt. The flue gas emission was measured with a professional semi-continuous multi-gas analyzer, (Vario plus industrial, MRU air Neckarsulm-Obereisesheim. Data showed a lower emission of fossil fuel compared to corn in family boilers in reference to pollutants in the flue gas (NOx, SO2 and CO. In a particular way the biomass combustion makes a higher concentration of carbon monoxide (for an incomplete combustion because there is not a good mixing between fuel and air and nitrogen oxides (in relation at a higher content of nitrogen in herbaceous biomass in comparison to another fuel.

  4. Modeling the influence of potassium content and heating rate on biomass pyrolysis

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Surup, Gerrit; Shapiro, Alexander

    2017-01-01

    . The shrinking particle model considers internal and external heat transfer limitations and incorporates catalytic effects of potassium on the product yields. Modeling parameters were tuned with experimentally determined char yields at high heating rates (>200 K s−1) using a wire mesh reactor, a single particle...... burner, and a drop tube reactor. The experimental data demonstrated that heating rate and potassium content have significant effects on the char yield. The importance of shrinkage on the devolatilization time becomes greater with increasing particle size, but showed little influence on the char yields....

  5. Performance Assessment Of Local Biomass Powered Cereal Drier Used By Small-Scale Kenyan Farmers

    OpenAIRE

    Madaraka F Mwema; Kimayu S. Musau; Ngugi J. Mburu

    2015-01-01

    Abstract Recent studies have revealed that drying maize using biomass driers increase the quality of grains delays insect infestation mold and aflatoxin contamination in relation to direct sunlight drying. Most importantly biomass drying takes shorter time. It is therefore important to undertake performance of these driers to investigate the possibility of empirical control of such systems in remote areas. In this paper we present results of thermal performance of typical biomass-powered drie...

  6. A model for allometric scaling of mammalian metabolism with ambient heat loss

    KAUST Repository

    Kwak, Ho Sang

    2016-02-02

    Background Allometric scaling, which represents the dependence of biological trait or process relates on body size, is a long-standing subject in biological science. However, there has been no study to consider heat loss to the ambient and an insulation layer representing mammalian skin and fur for the derivation of the scaling law of metabolism. Methods A simple heat transfer model is proposed to analyze the allometry of mammalian metabolism. The present model extends existing studies by incorporating various external heat transfer parameters and additional insulation layers. The model equations were solved numerically and by an analytic heat balance approach. Results A general observation is that the present heat transfer model predicted the 2/3 surface scaling law, which is primarily attributed to the dependence of the surface area on the body mass. External heat transfer effects introduced deviations in the scaling law, mainly due to natural convection heat transfer which becomes more prominent at smaller mass. These deviations resulted in a slight modification of the scaling exponent to a value smaller than 2/3. Conclusion The finding that additional radiative heat loss and the consideration of an outer insulation fur layer attenuate these deviation effects and render the scaling law closer to 2/3 provides in silico evidence for a functional impact of heat transfer mode on the allometric scaling law in mammalian metabolism.

  7. Influence of scale deposit and its thickness on the heat exchanger operational efficiency

    Science.gov (United States)

    Kocharyan, E. V.; Skiba, E. D.; Levina, E. Y.

    2017-11-01

    Materials submitted provide for the research results of the problem of scale formation in heat exchangers and show results of calculations of scale type and thickness impact on heat transfer factor and on heat exchanger overall energy efficiency with regard to heat exchanger hydraulic resistance increase. Calculations have been carried out using the example of heat exchanger PV1 (∏B1) 219-2-G-1, 6-6-UZ, manufactured as per State Standard (GOST) 27590-2005. On the basis of calculations performed recommendations on maximum allowable thickness of scale crust of different type, after scaling of which the heat exchanger operation may infringe the technological process, have been elaborated.

  8. A model for allometric scaling of mammalian metabolism with ambient heat loss

    Directory of Open Access Journals (Sweden)

    Ho Sang Kwak

    2016-03-01

    Conclusion: The finding that additional radiative heat loss and the consideration of an outer insulation fur layer attenuate these deviation effects and render the scaling law closer to 2/3 provides in silico evidence for a functional impact of heat transfer mode on the allometric scaling law in mammalian metabolism.

  9. Heating and Large Scale Dynamics of the Solar Corona

    Science.gov (United States)

    Schnack, Dalton D.

    2000-01-01

    The effort was concentrated in the areas: coronal heating mechanism, unstructured adaptive grid algorithms, numerical modeling of magnetic reconnection in the MRX experiment: effect of toroidal magnetic field and finite pressure, effect of OHMIC heating and vertical magnetic field, effect of dynamic MESH adaption.

  10. Design, scale-up, Six Sigma in processing different feedstocks in a fixed bed downdraft biomass gasifier

    Science.gov (United States)

    Boravelli, Sai Chandra Teja

    This thesis mainly focuses on design and process development of a downdraft biomass gasification processes. The objective is to develop a gasifier and process of gasification for a continuous steady state process. A lab scale downdraft gasifier was designed to develop the process and obtain optimum operating procedure. Sustainable and dependable sources such as biomass are potential sources of renewable energy and have a reasonable motivation to be used in developing a small scale energy production plant for countries such as Canada where wood stocks are more reliable sources than fossil fuels. This thesis addresses the process of thermal conversion of biomass gasification process in a downdraft reactor. Downdraft biomass gasifiers are relatively cheap and easy to operate because of their design. We constructed a simple biomass gasifier to study the steady state process for different sizes of the reactor. The experimental part of this investigation look at how operating conditions such as feed rate, air flow, the length of the bed, the vibration of the reactor, height and density of syngas flame in combustion flare changes for different sizes of the reactor. These experimental results also compare the trends of tar, char and syngas production for wood pellets in a steady state process. This study also includes biomass gasification process for different wood feedstocks. It compares how shape, size and moisture content of different feedstocks makes a difference in operating conditions for the gasification process. For this, Six Sigma DMAIC techniques were used to analyze and understand how each feedstock makes a significant impact on the process.

  11. Clean and efficient application of biomass for production of power and heat - Phase 3 in a long-term strategic research project

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.J.; Jensen, A.D.; Jensen, P.A.; Johnsson, J.E.; Dam-Johansen, K.

    2002-06-01

    This project contains activities on: Rheology of ashes from co-firing of coal and biomass; Investigation of ash and deposit formation in full-scale utility boilers; and Selective catalytic reduction: Deactivation under biomass combustion. A fly ash and deposit investigation was carried out as part of the SK Power Company test programme on co-firing of biomasses in a grate-fired boiler. The alternative biomasses (wood chips, olive stones and shea nuts) contain more K, S, and Cl, than wheat straw, and higher fly ash mass loading (mass of fly ash/volume of flue gas) was observed when co-firing alternative biomasses with wheat straw. Anyhow, no significant change in deposit structure when co-firing alkali-rich biomass was observed: KCl is glues residual ash particles together, independent of the feedstock mixture. Thus it can be concluded that co-firing of the actual biomasses in boilers designed for straw-firing, at the present shares is not problematic, from an ash formation and/or deposit build-up point-of-view. Anyhow the increase in ash mass loading in the flue gas, may cause increased build-up of particulate deposits in the convective pass of the boiler. Mature deposit samples from the Masnedoe and Ensted straw-fired boilers were investigated by SEM and EDX. Each deposit sample was classified into an inner, an intermediate, and an outer main layer. The outermost deposit layers at Masnedoe and Ensted looked chemically quite similar, even though they were of different colours. The intermediate layer at Ensted contained many Si- and Ca-rich particles glued together by melted KCI, while the intermediate deposit layers at Masnedoe were different. Since the straw fuels probably are similar, the differences observed in the deposit chemistry must be induced by the higher temperature of the Masnedoe deposit. An experimental method has been set up for viscosity determinations on ashes from co-firing with wheat straw. The method contains a pre-treatment of the ashes, where

  12. Model Research of Gas Emissions From Lignite and Biomass Co-Combustion in a Large Scale CFB Boiler

    Directory of Open Access Journals (Sweden)

    Krzywański Jarosław

    2014-06-01

    Full Text Available The paper is focused on the idea of a combustion modelling of a large-scale circulating fluidised bed boiler (CFB during coal and biomass co-combustion. Numerical computation results for three solid biomass fuels co-combustion with lignite are presented in the paper. The results of the calculation showed that in previously established kinetics equations for coal combustion, some reactions had to be modified as the combustion conditions changed with the fuel blend composition. Obtained CO2, CO, SO2 and NOx emissions are located in borders of ± 20% in the relationship to the experimental data. Experimental data was obtained for forest biomass, sunflower husk, willow and lignite cocombustion tests carried out on the atmospheric 261 MWe COMPACT CFB boiler operated in PGE Turow Power Station in Poland. The energy fraction of biomass in fuel blend was: 7%wt, 10%wt and 15%wt. The measured emissions of CO, SO2 and NOx (i.e. NO + NO2 were also shown in the paper. For all types of biomass added to the fuel blends the emission of the gaseous pollutants was lower than that for coal combustion.

  13. High nutrient removal rate from swine wastes and protein biomass production by full-scale duckweed ponds.

    Science.gov (United States)

    Mohedano, Rodrigo A; Costa, Rejane H R; Tavares, Flávia A; Belli Filho, Paulo

    2012-05-01

    Duckweed ponds have been successfully used in swine waste polishing, generating a biomass with high protein content. Therefore, the present study evaluated the efficiency of two full-scale duckweed ponds considering nutrient recovery from a piggery farm effluent (produced by 300 animals), as well as the biomass yield and crude protein (CP) content. A significant improvement in the effluent quality was observed, with the removal of 98.0% of the TKN (Total Kjeldahl Nitrogen) and 98.8% of the TP (Total Phosphorous), on average. The observed nitrogen removal rate is one of the highest reported (4.4 g/m(2)day of TKN). Additionally, the dissolved oxygen level rose from 0.0 to 3.0mg/L, on average. The two ponds together produced over 13 tons of biomass (68 t/ha year of dry biomass), with 35% crude protein content. Because of the excellent nutrient removal and protein biomass production, the duckweed ponds revealed a great potential for the polishing and valorisation of swine waste, under the presented conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Performance Analysis of Solar Assisted Fluidized Bed Dryer Integrated Biomass Furnace with and without Heat Pump for Drying of Paddy

    Directory of Open Access Journals (Sweden)

    M. Yahya

    2016-01-01

    Full Text Available The performances of a solar assisted fluidized bed dryer integrated biomass furnace (SA-FBDIBF and a solar assisted heat pump fluidized bed dryer integrated biomass furnace (SAHP-FBDIBF for drying of paddy have been evaluated, and also drying kinetics of paddy were determined. The SA-FBDIBF and the SAHP-FBDIBF were used to dry paddy from 11 kg with moisture content of 32.85% db to moisture content of 16.29% db (14% wb under an air mass flow rate of 0.1037 kg/s within 29.73 minutes and 22.95 minutes, with average temperatures and relative humidities of 80.3°C and 80.9°C and 12.28% and 8.14%, respectively. The average drying rate, specific energy consumption, and specific moisture extraction rate were 0.043 kg/minute and 0.050 kg/minute, 5.454 kWh/kg and 4.763 kWh/kg, and 0.204 kg/kWh and 0.241 kg/kWh for SA-FBDIBF and SAHP-FBDIBF, respectively. In SA-FBDIBF and SAHP-FBDIBF, the dryer thermal efficiencies were average values of 12.28% and 15.44%; in addition, the pickup efficiencies were 33.55% and 43.84% on average, whereas the average solar and biomass fractions were 10.9% and 10.6% and 36.6% and 30.4% for SA-FBDIBF and SAHP-FBDIBF, respectively. The drying of paddy occurred in the falling rate period. The experimental dimensionless moisture content data were fitted to three mathematical models. Page’s model was found best to describe the drying behaviour of paddy.

  15. New Experimental Characterisation Methods for Solid Biomass Fuels to be used in Combined Heat and Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Gunnar Eriksson, (Energy Engineering Div., Luleaa Univ. of Technology, S-971 87 Luleaa (Sweden)); Nordgren, Daniel; Berg, Magnus (Vattenfall Research and Development AB, S-814 26 Aelvkarleby (Sweden))

    2008-10-15

    The replacement of fossil fuels will lead to an increasing demand for unconventional biofuels. Fuel characterisation to predict combustion properties and facilitate the choice of combustion applications is important to avoid costly and time-consuming mistakes. Traditional methods are developed mainly for coal. Therefore procedures adapted specifically for solid biomass fuels are needed. This work is a survey on approaches for combustion characterisation of biomass developed during the last ten years. Innovative characterisation methods of interest concern: 1) Fuel handling behaviour: grindablility, erosion and abrasion properties. 2) Combustion characterisation: devolatilisation properties (important for ignition and flame stability), char burnout time. 3) Slagging and fouling properties of ash: ash particle formation, ash particle size distribution, ash composition, melting and gasification temperatures, slagging of bottom ash, reducing the risk by mixing with other fuels or using fuel additives and choice of suitable combustion applications for specific fuels. The main conclusions are: 1) a method to measure grindability which takes electric power consumption into account is needed as the Hardgrove Grindability Index used for coal grinding is pointless for biofuels, 2) there is a need to develop convenient low-cost methods to measure slagging and fouling tendencies, devolatilisation kinetics and char burnout for high heating rates found in fluidised beds and powder burners

  16. Role of steel slags on biomass/carbon dioxide gasification integrated with recovery of high temperature heat.

    Science.gov (United States)

    Sun, Yongqi; Liu, Qianyi; Wang, Hao; Zhang, Zuotai; Wang, Xidong

    2017-01-01

    Disposal of biomass in the agriculture and steel slags in the steel industry provides a significant solution toward sustainability in China. Herein these two sectors were creatively combined as a novel method, i.e., biomass/CO 2 gasification using waste heat from hot slags where the influence of chemical compositions of steel slags, characterized as iron oxide content and basicity, on gasification thermodynamics, was systemically reported for the first time. Both the target gases of CO, H 2 and CH 4 and the polluted gases of NH 3 , NO and NO 2 were considered. It was first found that an increasing iron content and slag basicity continuously improved the CO yield at 600-1000°C and 800-1000°C, respectively; while the effect on polluted gas releases was limited. Moreover, the solid wastes after gasification could be utilized to provide nutrients and improve the soil in the agriculture, starting from which an integrated modern system was proposed herein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effects of biomass burning on climate, accounting for heat and moisture fluxes, black and brown carbon, and cloud absorption effects

    Science.gov (United States)

    Jacobson, Mark Z.

    2014-07-01

    This paper examines the effects on climate and air pollution of open biomass burning (BB) when heat and moisture fluxes, gases and aerosols (including black and brown carbon, tar balls, and reflective particles), cloud absorption effects (CAEs) I and II, and aerosol semidirect and indirect effects on clouds are treated. It also examines the climate impacts of most anthropogenic heat and moisture fluxes (AHFs and AMFs). Transient 20 year simulations indicate BB may cause a net global warming of 0.4 K because CAE I ( 32% of BB warming), CAE II, semidirect effects, AHFs ( 7%), AMFs, and aerosol absorption outweigh direct aerosol cooling and indirect effects, contrary to previous BB studies that did not treat CAEs, AHFs, AMFs, or brown carbon. Some BB warming can be understood in terms of the anticorrelation between instantaneous direct radiative forcing (DRF) changes and surface temperature changes in clouds containing absorbing aerosols. BB may cause 250,000 (73,000-435,000) premature mortalities/yr, with >90% from particles. AHFs from all sources and AMFs + AHFs from power plants and electricity use each may cause a statistically significant +0.03 K global warming. Solar plus thermal-IR DRFs were +0.033 (+0.027) W/m2 for all AHFs globally without (with) evaporating cooling water, +0.009 W/m2 for AMFs globally, +0.52 W/m2 (94.3% solar) for all-source BC outside of clouds plus interstitially between cloud drops at the cloud relative humidity, and +0.06 W/m2 (99.7% solar) for BC inclusions in cloud hydrometeor particles. Modeled post-1850 biomass, biofuel, and fossil fuel burning, AHFs, AMFs, and urban surfaces accounted for most observed global warming.

  18. Forest biomass supply logistics solution to feed a commercial scale biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Ranta, T.; Jaeppinen, O.-J.; Karttunen, K. (Lappeenranta Univ. of Technology, Mikkeli (Finland)), e-mail: tapio.ranta@lut.fi

    2010-07-01

    Finnish forest companies aim to produce biodiesel based on the Fischer-Tropsch process from forest residues. This study presents method to evaluate biomass availability and supply costs to the selected biorefinery site. Forest-owners' willingness to sell, buyers' market share, and regional competition were taken into account when biomass availability was evaluated. Supply logistics was based either on direct truck transportation deliveries from forest or on railway / waterway transportation via regional terminals. The large biomass need of a biorefinery demanded both of these supply structures, since the procurement area was larger than the traditional supply area used for CHP plants in Finland. The average supply cost was EUR 15 / MWh for an annual supply of 2 TWh of forest biomass. Truck transportation of chips made from logging residues covered 70 % of the total volume, since direct forest chip deliveries from forest were the most competitive supply solution in terms of direct supply costs. The better supply security and lower vehicle capacity needs are issues that would favour also terminal logistics with other raw-material sources in practical operations. One finding was that the larger the biomass need, the less the variation in biomass availability and supply costs, since almost the whole country will serve as a potential supply area. Biomass import possibilities were not considered in this study. (orig.)

  19. Optimization of Biomass-Fuelled Combined Cooling, Heating and Power (CCHP) Systems Integrated with Subcritical or Transcritical Organic Rankine Cycles (ORCs)

    OpenAIRE

    Daniel Maraver; Sylvain Quoilin; Javier Royo

    2014-01-01

    This work is focused on the thermodynamic optimization of Organic Rankine Cycles (ORCs), coupled with absorption or adsorption cooling units, for combined cooling heating and power (CCHP) generation from biomass combustion. Results were obtained by modelling with the main aim of providing optimization guidelines for the operating conditions of these types of systems, specifically the subcritical or transcritical ORC, when integrated in a CCHP system to supply typical heating and cooling deman...

  20. Paths to bioenergy villages. A guideline for a independent supply of heat and electricity based on biomass in rural area. 3. ed.; Wege zum Bioenergiedorf. Leitfaden fuer eine eigenstaendige Waerme- und Stromversrogung auf Basis von Biomasse im laendlichen Raum

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, Hans; Eigner-Thiel, Swantje; Girschner, Walter; Karpenstein-Machan, Marianne; Roland, Folker; Ruwisch, Volker; Sauer, Benedikt; Schmuck, Peter

    2010-12-15

    Bioenergy villages are one component for the sustainable energy supply in rural areas. The guideline under consideration is intended to encourage people in villages to switch their heat supply and electricity supply on the bases of biomass. The focus of this process-oriented guideline is on: (1) A presentation of the social feasibility, especially the involvement, motivation and encouragement of the population; (2) The presentation of concepts for a nature-friendly cultivation of the required biomass; (3) The treatment of economic and legal issues from the perspective of the people involved.

  1. Heat and mass transfer intensification and shape optimization a multi-scale approach

    CERN Document Server

    2013-01-01

    Is the heat and mass transfer intensification defined as a new paradigm of process engineering, or is it just a common and old idea, renamed and given the current taste? Where might intensification occur? How to achieve intensification? How the shape optimization of thermal and fluidic devices leads to intensified heat and mass transfers? To answer these questions, Heat & Mass Transfer Intensification and Shape Optimization: A Multi-scale Approach clarifies  the definition of the intensification by highlighting the potential role of the multi-scale structures, the specific interfacial area, the distribution of driving force, the modes of energy supply and the temporal aspects of processes.   A reflection on the methods of process intensification or heat and mass transfer enhancement in multi-scale structures is provided, including porous media, heat exchangers, fluid distributors, mixers and reactors. A multi-scale approach to achieve intensification and shape optimization is developed and clearly expla...

  2. Advances in Large-Scale Solar Heating and Long Term Storage in Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    According to (the) information from the European Large-Scale Solar Heating Network, (See http://www.hvac.chalmers.se/cshp/), the area of installed solar collectors for large-scale application is in Europe, approximately 8 mill m2, corresponding to about 4000 MW thermal power. The 11 plants...... Central Solar Heating Plants, servicing District Heating and related developments in large-scale thermal storage. Central solar heating today is a mature and economic realistic solution for district heating based on a renewable source. The cost for solar collectors has decreased by nearly ¼ during...... the last 10 years and the corresponding cost per collector area for the final installed plant is kept constant, even so the solar production is increased. Unfortunately large-scale seasonal storage was not able to keep up with the advances in solar technology, at least for pit water and gravel storage...

  3. Biomass burning aerosol impact on surface winds during the 2010 Russian heat wave

    Science.gov (United States)

    Baró, R.; Lorente-Plazas, R.; Montávez, J. P.; Jiménez-Guerrero, P.

    2017-01-01

    This paper elucidates the impact of biomass burning aerosols (BB) on surface winds for the Russian fires episode during 25 July to 15 August 2010. The methodology consists of three Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulations over Europe differing in the inclusion (or not) of aerosol-radiation and aerosol-cloud interactions. The presence of BB reduces the 10 m wind speed over Russia during this fire event by 0.2 m s-1 (10%). Aerosol interactions imply a decrease of the shortwave downwelling radiation at the surface leading to a reduction of the 2 m temperature. This decrease reduces the turbulence flux, developing a more stable planetary boundary layer. Moreover, cooling favors an increase of the surface pressure over Russian area and also it extends nearby northern Europe.

  4. Experimental study of Large-scale cryogenic Pulsating Heat Pipe

    Science.gov (United States)

    Barba, Maria; Bruce, Romain; Bonelli, Antoine; Baudouy, Bertrand

    2017-12-01

    Pulsating Heat Pipes (PHP) are passive two-phase heat transfer devices consisting of a long capillary tube bent into many U-turns connecting the condenser part to the evaporator part. They are thermally driven by an oscillatory flow of liquid slugs and vapor plugs coming from phase changes and pressure differences along the tube. The coupling of hydrodynamic and thermodynamic effects allows high heat transfer performances. Three closed-loop pulsating heat pipes have been developed by the DACM (Department of Accelerators, Cryogenics and Magnetism) of CEA Paris-Saclay, France. Each PHP measures 3.7 meters long (0.35 m for the condenser and the evaporator and 3 m for the adiabatic part), being almost 20 times longer than the longest cryogenic PHP tested. These PHPs have 36, 22 and 12 parallel channels. Numerous tests have been performed in horizontal position (the closest configuration to non-gravity) using nitrogen as working fluid, operating between 75 and 90 K. The inner and outer diameters of the stainless steel capillary tubes are 1.5 and 2 mm respectively. The PHPs were operated at different filling ratios (20 to 90 %), heat input powers (3 to 20 W) and evaporator and condenser temperatures (75 to 90 K). As a result, the PHP with 36 parallel channels achieves a certain level of stability during more than thirty minutes with an effective thermal conductivity up to 200 kW/m.K at 10 W heat load and during forty minutes with an effective thermal conductivity close to 300 kW/m.K at 5 W heat load.

  5. Integration of large-scale heat pumps in the district heating systems of Greater Copenhagen

    DEFF Research Database (Denmark)

    Bach, Bjarne; Werling, Jesper; Ommen, Torben Schmidt

    2016-01-01

    This study analyses the technical and private economic aspects of integrating a large capacity of electric driven HP (heat pumps) in the Greater Copenhagen DH (district heating) system, which is an example of a state-of-the-art large district heating system with many consumers and suppliers....... The analysis was based on using the energy model Balmorel to determine the optimum dispatch of HPs in the system. The potential heat sources in Copenhagen for use in HPs were determined based on data related to temperatures, flows, and hydrography at different locations, while respecting technical constraints...

  6. Scale/Analytical Analyses of Freezing and Convective Melting with Internal Heat Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ali S. Siahpush; John Crepeau; Piyush Sabharwall

    2013-07-01

    Using a scale/analytical analysis approach, we model phase change (melting) for pure materials which generate constant internal heat generation for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. The analysis also consider constant heat flux (in a cylindrical geometry).We show the time scales in which conduction and convection heat transfer dominate.

  7. BIOSEP: A NEW ETHANOL RECOVERY TECHNOLOGY FOR SMALL SCALE RURAL PRODUCTION OF ETHANOL FROM BIOMASS

    Science.gov (United States)

    Research activities on bioethanol have increased substantially as a result of the current concerns with energy security. Inexpensive biomass including forest residues, mill residues, agricultural residues, urban wood wastes and dedicated energy corps that exists in abundance acr...

  8. Dynamic Modeling and Validation of a Biomass Hydrothermal Pretreatment Process - A Demonstration Scale Study

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail; Blanke, Mogens; Jakobsen, Jon Geest

    2015-01-01

    Hydrothermal pretreatment of lignocellulosic biomass is a cost effective technology for second generation biorefineries. The process occurs in large horizontal and pressurized thermal reactors where the biomatrix is opened under the action of steam pressure and temperature to expose cellulose...

  9. Deodorization of Arthrospira platensis biomass for further scale-up food applications.

    Science.gov (United States)

    Cuellar-Bermúdez, Sara P; Barba-Davila, Bertha; Serna-Saldivar, Sergio O; Parra-Saldivar, Roberto; Rodriguez-Rodriguez, José; Morales-Davila, Sandra; Goiris, Koen; Muylaert, Koenraad; Chuck-Hernández, Cristina

    2017-12-01

    Given the importance of A. platensis as a potential food protein source, we describe an affordable deodorization process that does not significantly affect the nutritional value of algae biomass. Ethanol, acetone or hexane were used to deodorize algae biomass and then to identify the profile of volatile compounds associated with its distinctive odor. Sensorial characteristics were improved in the biomass cake after the proposed solvent extraction. Panelists identified the ethanolic extract with the most pronounced algae-related odor. Gas chromatography-mass spectrometry analysis showed that a mixture of 20 different compounds derived from fatty acids and amino acids contributed to the characteristic smell of A. platensis biomass. The results of the present study show that the ethanol solvent-free A. platensis biomass contained > 600 g kg-1 protein,  65% in vitro protein digestibility, similar to the original biomass. The Fourier transform infrared spectroscopy secondary protein structure was comparable among samples, indicating that the only change after ethanol extraction was a reduction of the algae smell. The various extraction procedures investigated in the present study were effective in deodorizing the algae biomass. The most effective protocol was the removal of odoriferous compounds with ethanol. This particular procedure yielded an algae biomass with an improved sensorial traits. The results of the present study should help with the identification of odoriferous compounds derived from fatty acids, pigments and proteins associated with A. platensis. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Biomass recalcitrance: a multi-scale, multi-factor, and conversion-specific property.

    Science.gov (United States)

    McCann, Maureen C; Carpita, Nicholas C

    2015-07-01

    Recalcitrance of plant biomass to enzymatic hydrolysis for biofuel production is thought to be a property conferred by lignin or lignin-carbohydrate complexes. However, chemical catalytic and thermochemical conversion pathways, either alone or in combination with biochemical and fermentative pathways, now provide avenues to utilize lignin and to expand the product range beyond ethanol or butanol. To capture all of the carbon in renewable biomass, both lignin-derived aromatics and polysaccharide-derived sugars need to be transformed by catalysts to liquid hydrocarbons and high-value co-products. We offer a new definition of recalcitrance as those features of biomass which disproportionately increase energy requirements in conversion processes, increase the cost and complexity of operations in the biorefinery, and/or reduce the recovery of biomass carbon into desired products. The application of novel processing technologies applied to biomass reveal new determinants of recalcitrance that comprise a broad range of molecular, nanoscale, and macroscale factors. Sampling natural genetic diversity within a species, transgenic approaches, and synthetic biology approaches are all strategies that can be used to select biomass for reduced recalcitrance in various pretreatments and conversion pathways. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Scale-up study of oxalic acid pretreatment of agricultural lignocellulosic biomass for the production of bioethanol

    Science.gov (United States)

    Jae-Won Lee; Carl J. Houtman; Hye-Yun Kim; In-Gyu Choi; Thomas W. Jeffries

    2011-01-01

    Building on our laboratory-scale optimization, oxalic acid was used to pretreat corncobs on the pilotscale. The hydrolysate obtained after washing the pretreated biomass contained 32.55 g/l of xylose, 2.74 g/l of glucose and low concentrations of inhibitors. Ethanol production, using Scheffersomyces stipitis, from this hydrolysate was 10.3 g/l, which approached the...

  12. Saccharification Performances of Miscanthus at the Pilot and Miniaturized Assay Scales: Genotype and Year Variabilities According to the Biomass Composition

    Directory of Open Access Journals (Sweden)

    Nassim Belmokhtar

    2017-05-01

    Full Text Available HIGHLIGHTSBiomass production and cell wall composition are differentially impacted by harvesting year and genotypes, influencing then cellulose conversion in miniaturized assay.Using a high-throughput miniaturized and semi-automated method for performing the pretreatment and saccharification steps at laboratory scale allows for the assessment of these factors on the biomass potential for producing bioethanol before moving to the industrial scale.The large genetic diversity of the perennial grass miscanthus makes it suitable for producing cellulosic ethanol in biorefineries. The saccharification potential and year variability of five genotypes belonging to Miscanthus × giganteus and Miscanthus sinensis were explored using a miniaturized and semi-automated method, allowing the application of a hot water treatment followed by an enzymatic hydrolysis. The studied genotypes highlighted distinct cellulose conversion yields due to their distinct cell wall compositions. An inter-year comparison revealed significant variations in the biomass productivity and cell wall compositions. Compared to the recalcitrant genotypes, more digestible genotypes contained higher amounts of hemicellulosic carbohydrates and lower amounts of cellulose and lignin. In contrast to hemicellulosic carbohydrates, the relationships analysis between the biomass traits and cellulose conversion clearly showed the same negative effect of cellulose and lignin on cellulose digestion. The miniaturized and semi-automated method we developed was usable at the laboratory scale and was reliable for mimicking the saccharification at the pilot scale using a steam explosion pretreatment and enzymatic hydrolysis. Therefore, this miniaturized method will allow the reliable screening of many genotypes for saccharification potential. These findings provide valuable information and tools for breeders to create genotypes combining high yield, suitable biomass composition, and high saccharification

  13. Ash transformation and deposit build-up during biomass suspension and grate firing: Full-scale experimental studies

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming

    2012-01-01

    An attractive option for reducing the net CO2 emissions is to substitute coal with biomass in large power plant boilers. However, the presence of chlorine (Cl) and alkali metals (K, Na) in biomassmay induce large operational problems due to ash deposit formation on the superheater tubes. The aim...... on similar levels. This was observed even though the concentration of fly ash in the flue gas was significantly higher during straw suspension firing. The influence of co-combustion of wood with straw on deposit formation rate, probe heat uptake and deposit characteristicswas also investigated during...

  14. Stochastic analysis of field-scale heat advection in heterogeneous aquifers

    Directory of Open Access Journals (Sweden)

    C.-M. Chang

    2012-03-01

    Full Text Available Owing to the analogy between the solute and heat transport processes, it can be expected that the rate of growth of the spatial second moments of the heat flux in a heterogeneous aquifer over relatively large space scales is greater than that predicted by applying the classical heat transport model. The motivation of stochastic analysis of heat transport at the field scale is therefore to quantify the enhanced growth of the field-scale second moments caused by the spatially varying specific discharge field. Within the framework of stochastic theory, an effective advection-dispersion equation containing effective parameters (namely, the macrodispersion coefficients is developed to model the mean temperature field. The rate of growth of the field-scale spatial second moments of the mean temperature field in the principal coordinate directions is described by the macrodispersion coefficient. The variance of the temperature field is also developed to characterize the reliability to be anticipated in applying the mean heat transport model. It is found that the heterogeneity of the medium and the correlation length of the log hydraulic conductivity are important in enhancing the field-scale heat advection, while the effective thermal conductivity plays the role in reducing the field-scale heat advection.

  15. Factors Controlling Soil Microbial Biomass and Bacterial Diversity and Community Composition in a Cold Desert Ecosystem: Role of Geographic Scale.

    Directory of Open Access Journals (Sweden)

    David J Van Horn

    Full Text Available Understanding controls over the distribution of soil bacteria is a fundamental step toward describing soil ecosystems, understanding their functional capabilities, and predicting their responses to environmental change. This study investigated the controls on the biomass, species richness, and community structure and composition of soil bacterial communities in the McMurdo Dry Valleys, Antarctica, at local and regional scales. The goals of the study were to describe the relationships between abiotic characteristics and soil bacteria in this unique, microbially dominated environment, and to test the scale dependence of these relationships in a low complexity ecosystem. Samples were collected from dry mineral soils associated with snow patches, which are a significant source of water in this desert environment, at six sites located in the major basins of the Taylor and Wright Valleys. Samples were analyzed for a suite of characteristics including soil moisture, pH, electrical conductivity, soil organic matter, major nutrients and ions, microbial biomass, 16 S rRNA gene richness, and bacterial community structure and composition. Snow patches created local biogeochemical gradients while inter-basin comparisons encompassed landscape scale gradients enabling comparisons of microbial controls at two distinct spatial scales. At the organic carbon rich, mesic, low elevation sites Acidobacteria and Actinobacteria were prevalent, while Firmicutes and Proteobacteria were dominant at the high elevation, low moisture and biomass sites. Microbial parameters were significantly related with soil water content and edaphic characteristics including soil pH, organic matter, and sulfate. However, the magnitude and even the direction of these relationships varied across basins and the application of mixed effects models revealed evidence of significant contextual effects at local and regional scales. The results highlight the importance of the geographic scale of

  16. ORC case studies. Electricity production in biomass fired district heating plant or from waste heat in pulp mill; ORC-fallstudier. Elproduktion i biobraensleeldat vaermeverk eller fraan spillvaerme i massabruk

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Barbara

    2009-11-15

    In this report electricity yields and costs of electricity production is discussed two case studies. The first case is a district heating application with an ORC connected to a biomass fuelled oven. The second case is a waste heat application an ORC module connected to waste water from a pulp and paper plant. In the case study an ORC based biomass fuelled cogeneration plant is installed in the district heating net of a medium size Swedish municipality, Aelmhult. The plant consists of a biomass fuelled oven, a thermal oil boiler for heat transfer from flue gas to ORC cycle, and an ORC unit which is cooled by the district heating net. At full load the plant produces 9,6 MW heat and 2,2 MW (net) electricity. The plant has a split cycle ORC system. In the split cycle heat is transferred in two separate thermal oil circuits. In the main thermal oil circuit, operating at 250-3000 C, heat is transferred from the flue gas to the ORC unit. The second thermal oil circuit, operating at 130-250 deg C, transferers additional heat to the ORC unit. This heat is utilised for pre-heating in the ORC cycle, thus increasing the electricity yield by 10% compared to the yield of a single cycle system. The ORC unit has a maximum electricity yield of 2,3 MW gross and 2,2 MW net, based on district heating temperatures of 600 C for district heating return flow and 900 C for forward flow. The plant will be in operation 8300 h per year. Of this 3000 h is full load and the remaining time part load. The yearly heat production will be 53 GWh. The yearly electricity production will be 12 GWh net, which corresponds to a mean electricity yield of 1,4 MW net. With a yearly electricity production of 12 GWh net, the cost of produced electricity is 1,04 SEK/kWh. When the income from sold green certificates for biomass based electricity is deducted, the cost is reduced by circa 0,30 SEK/kWh.Normally, a biomass fuelled cogeneration plant, using wet biomass, would be equipped with flue gas condensation

  17. Full Scale Investigation of the Dynamic Heat Storage of Concrete Decks with PCM and Enhanced Heat Transfer Surface Area

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2013-01-01

    The paper presents the full-scale experimental investigation of the dynamic heat storage potential of the prefabricated hollow core deck elements with and without phase change material (PCM) and with and without increased bottom surface area of the decks. In the presented investigation five types...... can result in the increased heat amount that can be transferred and stored in the heavy construction element during the diurnal indoor temperature fluctuations.......The paper presents the full-scale experimental investigation of the dynamic heat storage potential of the prefabricated hollow core deck elements with and without phase change material (PCM) and with and without increased bottom surface area of the decks. In the presented investigation five types...

  18. Scalings for unsteady natural convection boundary layers on an evenly heated plate with time-dependent heating flux

    Science.gov (United States)

    Lin, Wenxian; Armfield, S. W.

    2013-12-01

    It is of fundamental significance, especially with regard to application, to fully understand the flow behavior of unsteady natural convection boundary layers on a vertical plate heated by a time-dependent heat flux. Such an understanding is currently scarce. In this paper, the scaling analysis by Lin et al. [Phys. Rev. E 79, 066313 (2009), 10.1103/PhysRevE.79.066313] using a simple three-region structure for the unsteady natural convection boundary layer of a homogeneous Newtonian fluid with Pr >1 under isothermal heating was substantially extended for the case when the heating is due to a time-varying sinusoidal heat flux. A series of scalings was developed for the thermal boundary thickness, the plate temperature, the viscous boundary thicknesses, and the maximum vertical velocity within the boundary layer, which are the major parameters representing the flow behavior, in terms of the governing parameters of the flow, i.e., the Rayleigh number Ra, the Prandtl number Pr, and the dimensionless natural frequency fn of the time-varying sinusoidal heat flux, at the start-up stage, at the transition time scale which represents the ending of the start-up stage and the beginning of the transitional stage of the boundary-layer development, and at the quasi-steady stage. These scalings were validated by comparison to 10 full numerical solutions of the governing equations with Ra, Pr, and fn in the ranges 106≤Ra≤109, 3≤Pr≤100, and 0.01≤fn≤0.1 and were shown in general to provide an accurate description of the flow at different development stages, except for high-Pr runs in which a further, although weak, Pr dependence is present, which cannot be accurately predicted by the current scaling analysis using the simple three-region structure, attributed to the non-boundary-layer nature of the velocity field with high-Pr fluids. Some scalings at the transition time scale and at the quasi-steady stage also produce noticeable deviations from the numerical results when

  19. Flux balance analysis of genome-scale metabolic model of rice (Oryza sativa): aiming to increase biomass.

    Science.gov (United States)

    Shaw, Rahul; Kundu, Sudip

    2015-10-01

    Due to socio-economic reasons, it is essential to design efficient stress-tolerant, more nutritious, high yielding rice varieties. A systematic understanding of the rice cellular metabolism is essential for this purpose. Here, we analyse a genome-scale metabolic model of rice leaf using Flux Balance Analysis to investigate whether it has potential metabolic flexibility to increase the biosynthesis of any of the biomass components. We initially simulate the metabolic responses under an objective to maximize the biomass components. Using the estimated maximum value of biomass synthesis as a constraint, we further simulate the metabolic responses optimizing the cellular economy. Depending on the physiological conditions of a cell, the transport capacities of intracellular transporters (ICTs) can vary. To mimic this physiological state, we randomly vary the ICTs' transport capacities and investigate their effects. The results show that the rice leaf has the potential to increase glycine and starch in a wide range depending on the ICTs' transport capacities. The predicted biosynthesis pathways vary slightly at the two different optimization conditions. With the constraint of biomass composition, the cell also has the metabolic plasticity to fix a wide range of carbon-nitrogen ratio.

  20. Energy Analysis of Cascade Heating with High Back-Pressure Large-Scale Steam Turbine

    Directory of Open Access Journals (Sweden)

    Zhihua Ge

    2018-01-01

    Full Text Available To reduce the exergy loss that is caused by the high-grade extraction steam of traditional heating mode of combined heat and power (CHP generating unit, a high back-pressure cascade heating technology for two jointly constructed large-scale steam turbine power generating units is proposed. The Unit 1 makes full use of the exhaust steam heat from high back-pressure turbine, and the Unit 2 uses the original heating mode of extracting steam condensation, which significantly reduces the flow rate of high-grade extraction steam. The typical 2 × 350 MW supercritical CHP units in northern China were selected as object. The boundary conditions for heating were determined based on the actual climatic conditions and heating demands. A model to analyze the performance of the high back-pressure cascade heating supply units for off-design operating conditions was developed. The load distributions between high back-pressure exhaust steam direct supply and extraction steam heating supply were described under various conditions, based on which, the heating efficiency of the CHP units with the high back-pressure cascade heating system was analyzed. The design heating load and maximum heating supply load were determined as well. The results indicate that the average coal consumption rate during the heating season is 205.46 g/kWh for the design heating load after the retrofit, which is about 51.99 g/kWh lower than that of the traditional heating mode. The coal consumption rate of 199.07 g/kWh can be achieved for the maximum heating load. Significant energy saving and CO2 emission reduction are obtained.

  1. Modelling of Temperature Profiles and Transport Scaling in Auxiliary Heated Tokamaks

    DEFF Research Database (Denmark)

    Callen, J.D.; Christiansen, J.P.; Cordey, J.G.

    1987-01-01

    -mode) scaling with input power, . The constant heat pinch or excess temperature gradient model leads to the offset linear law for the total stored energy W with Pin, W = τinc Pin + W(0), which describes JET auxiliary heating data quite well. It also provides definitions for the incremental energy confinement...

  2. The structural and hydration properties of heat-treated rice studied at multiple lenght scales

    NARCIS (Netherlands)

    Witek, M.M.; Weglarz, W.; Jong, de L.; Dalen, van G.; Blonk, J.C.G.; Heussen, P.; Velzen, van E.; As, van H.; Duynhoven, van J.P.M.

    2010-01-01

    The impact of heat-treatment on structure and hydration properties of rice was studied at different length scales (µm–nm). Heat-treatment introduced micro- and macro-pores within rice kernels (µCT) and, within intact cell walls, disintegrated starch granules were observed (SEM, CSLM). In native

  3. Air emissions of small-scale (< 10 MW) biomass boilers. Review of three field tests; Developpement d'un calorimetre a eau pour la dosimetrie au LNE-LNHB

    Energy Technology Data Exchange (ETDEWEB)

    Autret, E. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 49 - Angers (France)

    2011-01-15

    Objectives of greenhouse gases emission reduction, which encourages bio-energy development for heat purposes, are compatible with air-quality policies if the concept of clean biomass combustion is applied. This paper presents actual emission levels of atmospheric pollutants of small-scale (< 10 MW) biomass boilers from a review of three field tests carried out between 2007 and 2009. 31 biomass boilers have been audited to cover the large diversity of sites under operation in terms of fuels, power, flue-gas cleaning devices.. Results are compared to actual and forecasted regulations. The review shows that fuel quality and operation are key issues to ensure low emissions of organic pollutants (OC, VOC, CnHm, PCDD/F, PAH, PCB, HCB), SO{sub 2}, NO{sub x}, fine particulate matters, metallic compounds. Installation design (power, flue-gas cleaning techno logy) also has a major impact on organic pollutants and fine particulate matter emissions. A large majority of boilers have very low emission levels. Guidelines are finally stated to keep on promoting small-scale biomass boilers in order to be air-quality compatible and efficient to fight climate change. (author)

  4. Method for producing bio-fuel that integrates heat from carbon-carbon bond-forming reactions to drive biomass gasification reactions

    Science.gov (United States)

    Cortright, Randy D [Madison, WI; Dumesic, James A [Verona, WI

    2012-04-10

    A low-temperature catalytic process for converting biomass (preferably glycerol recovered from the fabrication of bio-diesel) to synthesis gas (i.e., H.sub.2/CO gas mixture) in an endothermic gasification reaction is described. The synthesis gas is used in exothermic carbon-carbon bond-forming reactions, such as Fischer-Tropsch, methanol, or dimethylether syntheses. The heat from the exothermic carbon-carbon bond-forming reaction is integrated with the endothermic gasification reaction, thus providing an energy-efficient route for producing fuels and chemicals from renewable biomass resources.

  5. Method for producing bio-fuel that integrates heat from carbon-carbon bond-forming reactions to drive biomass gasification reactions

    Science.gov (United States)

    Cortright, Randy D [Madison, WI; Dumesic, James A [Verona, WI

    2011-01-18

    A low-temperature catalytic process for converting biomass (preferably glycerol recovered from the fabrication of bio-diesel) to synthesis gas (i.e., H.sub.2/CO gas mixture) in an endothermic gasification reaction is described. The synthesis gas is used in exothermic carbon-carbon bond-forming reactions, such as Fischer-Tropsch, methanol, or dimethylether syntheses. The heat from the exothermic carbon-carbon bond-forming reaction is integrated with the endothermic gasification reaction, thus providing an energy-efficient route for producing fuels and chemicals from renewable biomass resources.

  6. Effect of reactions in small eddies on biomass gasification with eddy dissipation concept - Sub-grid scale reaction model.

    Science.gov (United States)

    Chen, Juhui; Yin, Weijie; Wang, Shuai; Meng, Cheng; Li, Jiuru; Qin, Bai; Yu, Guangbin

    2016-07-01

    Large-eddy simulation (LES) approach is used for gas turbulence, and eddy dissipation concept (EDC)-sub-grid scale (SGS) reaction model is employed for reactions in small eddies. The simulated gas molar fractions are in better agreement with experimental data with EDC-SGS reaction model. The effect of reactions in small eddies on biomass gasification is emphatically analyzed with EDC-SGS reaction model. The distributions of the SGS reaction rates which represent the reactions in small eddies with particles concentration and temperature are analyzed. The distributions of SGS reaction rates have the similar trend with those of total reactions rates and the values account for about 15% of the total reactions rates. The heterogeneous reaction rates with EDC-SGS reaction model are also improved during the biomass gasification process in bubbling fluidized bed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Large-scale heat pumps in sustainable energy systems: System and project perspectives

    Directory of Open Access Journals (Sweden)

    Blarke Morten B.

    2007-01-01

    Full Text Available This paper shows that in support of its ability to improve the overall economic cost-effectiveness and flexibility of the Danish energy system, the financially feasible integration of large-scale heat pumps (HP with existing combined heat and power (CHP plants, is critically sensitive to the operational mode of the HP vis-à-vis the operational coefficient of performance, mainly given by the temperature level of the heat source. When using ground source for low-temperature heat source, heat production costs increases by about 10%, while partial use of condensed flue gasses for low-temperature heat source results in an 8% cost reduction. Furthermore, the analysis shows that when a large-scale HP is integrated with an existing CHP plant, the projected spot market situation in The Nordic Power Exchange (Nord Pool towards 2025, which reflects a growing share of wind power and heat-supply constrained power generation electricity, further reduces the operational hours of the CHP unit over time, while increasing the operational hours of the HP unit. In result, an HP unit at half the heat production capacity as the CHP unit in combination with a heat-only boiler represents as a possibly financially feasible alternative to CHP operation, rather than a supplement to CHP unit operation. While such revised operational strategy would have impacts on policies to promote co-generation, these results indicate that the integration of large-scale HP may jeopardize efforts to promote co-generation. Policy instruments should be designed to promote the integration of HP with lower than half of the heating capacity of the CHP unit. Also it is found, that CHP-HP plant designs should allow for the utilization of heat recovered from the CHP unit’s flue gasses for both concurrent (CHP unit and HP unit and independent operation (HP unit only. For independent operation, the recovered heat is required to be stored. .

  8. Particle size distributions from laboratory-scale biomass fires using fast response instruments

    Science.gov (United States)

    S Hosseini; L. Qi; D. Cocker; D. Weise; A. Miller; M. Shrivastava; J.W. Miller; S. Mahalingam; M. Princevac; H. Jung

    2010-01-01

    Particle size distribution from biomass combustion is an important parameter as it affects air quality, climate modelling and health effects. To date, particle size distributions reported from prior studies vary not only due to difference in fuels but also difference in experimental conditions. This study aims to report characteristics of particle size distributions in...

  9. From a single pellet press to a bench scale pellet mill - Pelletizing six different biomass feedstocks

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Shang, Lei; Sárossy, Zsuzsa

    2016-01-01

    The increasing demand for biomass pellets requires the investigation of alternative raw materials for pelletizetion. In the present paper, the pelletization process of fescue, alfalfa, sorghum, triticale, miscanthus and willow is studied to determine if results obtained in a single pellet press...

  10. Biomimic design of multi-scale fabric with efficient heat transfer property

    Directory of Open Access Journals (Sweden)

    Fan Jie

    2012-01-01

    Full Text Available Wool fiber has a complex hierarchic structure. The multi-scale fibrils are assembled to form a tree-like channel net in wool fiber, providing an efficient heat transfer property. The optimal inner configuration of wool fiber can also be invited to biomimic design of textile fabrics to improve the thermal comfort of cloth. A heat transfer model of biomimic multi-scale fabric using the fractal derivative is established. Theoretical analysis indicates that the heat flux efficiency in the biomimic fabric can be 2 orders of magnitude comparing with that of the continuous medium.

  11. Increased combustion stability in modulating biomass boilers for district heating systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zethraeus, Bjoern; Olsson, Pernilla; Gummesson, Martin [Vaexjoe Univ. (Sweden). Dep. of Bioenergy Technology

    2002-04-01

    The ultimate aim of the development work performed at ITN was to provide a tool for the boiler designer, a tool to make good estimates as to the environmental performance of different boiler designs. In the longer perspective, such a predictive model may also be developed into a process control system predictor and thus improve boiler control with respect to dynamic mixing imperfections. To fulfil this aim there also has to be available a sufficiently fast measurement technique and part of ITN's work aimed at demonstrating that by digital methods may the time resolution of measured data be improved. The main deliverables from ITN were planned to be: A description of an algorithm to improve the time resolution of measured data by aid of digital back-calculation to provide measurement data with a time resolution comparable to the computational model with the lowest possible demands on measurement frequency. A transportable computer code to describe the dynamic behaviour of biomass-fired boilers with respect to hydrocarbon-, CO- and NO{sub x}-emissions. The program should be able to predict the distribution of concentrations of these gas components in a reasonably short computing time. An algorithm based on the use of Fourier transforms has been derived and tested of-line. Provided the gas analysis sampling system has a time constant r for its low-pass characteristic, even noisy signals may be reconstructed into time constant {tau}/2 if a clever filter is used to improve the signal/noise ratio. Further improvement is theoretically possible - but seems not realistic in practical cases. A computer code has been produced in MATLAB, a code that reproduces the dynamic mixing behaviour of realistic boilers. The most fundamental assumptions for the code have not been thoroughly verified but a number of comparisons have been made to different boilers and seem to indicate that the predictions are qualitatively correct. The code is based on a constant flow of fuel

  12. News from heat-pump research - Large-scale heat pumps, components, heat pumps and solar heating; News aus der Waermepumpen-Forschung - Gross-Waermepumpen, Komponenten, Waermepumpe und Solar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-06-15

    These proceedings summarise the presentations made at the 16{sup th} annual meeting held by the Swiss Federal Office of Energy's Heat Pump Research Program in Burgdorf, Switzerland. The proceedings include contributions on large-scale heat pumps, components and the activities of the heat pump promotion society. A summary of targets and trends in energy research in general is presented and an overview of the heat pump market in 2009 and future perspectives is given. International work within the framework of the International Energy Agency's heat pump group is reviewed, including solar - heat pump combinations. Field-monitoring and the analysis of large-scale heat pumps are discussed and the importance of the use of correct concepts in such installations is stressed. Large-scale heat pumps with carbon dioxide as working fluid are looked at, as are output-regulated air/water heat pumps. Efficient system solutions with heat pumps used both to heat and to cool are discussed. Deep geothermal probes and the potential offered by geothermal probes using carbon dioxide as a working fluid are discussed. The proceedings are rounded off with a list of useful addresses.

  13. Pilot-scale radio frequency pasteurisation of chili powder: heating uniformity and heating model.

    Science.gov (United States)

    Li, Yukun; Zhang, Yongdi; Lei, Yujie; Fu, Hongfei; Chen, Xiangwei; Wang, Yunyang

    2016-08-01

    Microbial contamination is a vital obstacle needed to overcome for food safety of condiments. Radio frequency (RF) pasteurisation is a new technology to solve this obstacle. Temperature distribution and heating uniformity of sample, which are influenced by different factors, are the most important things affecting the nutritional ingredients and microbial safety of sample in the process of RF pasteurisation. This study demonstrated the location of cold spot in chili powder by analysing temperature distribution in horizontal and vertical direction. The related models were established and the accuracy was verified. Cold spot located on the centre of sample surface in the process of RF pasteurisation. The averaged temperature of sample increased linearly. The uniformity index decreased as the averaged temperature increased. Both the correlation coefficient of two equations were greater than 0.91. The error value of heating rate and heating uniformity index was 0.54% and 0.75% between the measured value and predicted value. Electric field was not uniformly distributed between RF parallel-plate electrodes in the RF pasteurisation of chili powder. The heating models were reliable to predict experiment results with high precision and accuracy. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  14. Decentralised power generation using solid biomass - Know-how on combined heat and power generation for investors; Dezentrale Stromerzeugung mit Feststoffbiomasse

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, M.; Gaegauf, Ch.; Sattler, M.

    2007-01-15

    This comprehensive report made by the Centre of Appropriate Technology and Social Ecology in Langenbruck, Switzerland presents a summary of know-how for investors on combined heat and power generation using solid biomass in installations with an electrical rating of up to one megawatt. Topics covered include a review of the reasons for using biomass to generate electricity - with the results of an analysis of potential in Switzerland and the European Union - and of economic assessment methods for the choice of technology and manufacturers. A SWOT (strengths, weaknesses, opportunities and threats) analysis of technologies is presented and existing biomass-fired installations in Switzerland are listed. A comparison with centrally-refined combustibles is presented and examples of cost and profitability calculations are given. Finally technological background information is presented, including information on 'forgotten' technologies.

  15. Alkali chloride induced corrosion of superheaters under biomass firing conditions: Improved insights from laboratory scale studies

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2015-01-01

    One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed...... to the formation of corrosive deposits (rich in alkali chlorides) on the surfaces of the superheaters. Accordingly, an extensive number of fundamental investigations have been undertaken to understand the basic mechanisms behind the alkali chloride induced high temperature corrosion of superheaters (for example......, [1–3]). However, complete understanding of the corrosion mechanism under biomass-firing conditions has not yet been achieved. This is attributed partly to the complex nature of the corrosion process since there are many species produced from fuel combustion which can interact with one another...

  16. Driftless Area Initiative Biomass Energy Project

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Angie [Northeast Iowa Resource Conservation & Development, Inc., Postville, IA (United States); Bertjens, Steve [Natural Resources Conservation Service, Madison, WI (United States); Lieurance, Mike [Northeast Iowa Resource Conservation & Development, Inc., Postville, IA (United States); Berguson, Bill [Univ. of Minnesota, Minneapolis, MN (United States). Natural Resources Research Inst.; Buchman, Dan [Univ. of Minnesota, Minneapolis, MN (United States). Natural Resources Research Inst.

    2012-12-31

    The Driftless Area Initiative Biomass Energy Project evaluated the potential for biomass energy production and utilization throughout the Driftless Region of Illinois, Iowa, Minnesota and Wisconsin. The research and demonstration aspect of the project specifically focused on biomass energy feedstock availability and production potential in the region, as well as utilization potential of biomass feedstocks for heat, electrical energy production, or combined heat and power operations. The Driftless Region was evaluated because the topography of the area offers more acres of marginal soils on steep slopes, wooded areas, and riparian corridors than the surrounding “Corn Belt”. These regional land characteristics were identified as potentially providing opportunity for biomass feedstock production that could compete with traditional agriculture commodity crops economically. The project researched establishment methods and costs for growing switchgrass on marginal agricultural lands to determine the economic and quantitative feasibility of switchgrass production for biomass energy purposes. The project was successful in identifying the best management and establishment practices for switchgrass in the Driftless Area, but also demonstrated that simple economic payback versus commodity crops could not be achieved at the time of the research. The project also analyzed the availability of woody biomass and production potential for growing woody biomass for large scale biomass energy production in the Driftless Area. Analysis determined that significant resources exist, but costs to harvest and deliver to the site were roughly 60% greater than that of natural gas at the time of the study. The project contributed significantly to identifying both production potential of biomass energy crops and existing feedstock availability in the Driftless Area. The project also analyzed the economic feasibility of dedicated energy crops in the Driftless Area. High commodity crop prices

  17. Effect of lake water on algal biomass and microbial community structure in municipal wastewater-based lab-scale photobioreactors.

    Science.gov (United States)

    Krustok, I; Truu, J; Odlare, M; Truu, M; Ligi, T; Tiirik, K; Nehrenheim, E

    2015-08-01

    Photobioreactors are a novel environmental technology that can produce biofuels with the simultaneous removal of nutrients and pollutants from wastewaters. The aim of this study was to evaluate the effect of lake water inoculation on the production of algal biomass and phylogenetic and functional structure of the algal and bacterial communities in municipal wastewater-treating lab-scale photobioreactors. Inoculating the reactors with lake water had a significant benefit to the overall algal biomass growth and nutrient reduction in the reactors with wastewater and lake water (ratio 70/30 v/v). The metagenome-based survey showed that the most abundant algal phylum in these reactors was Chlorophyta with Scenedesmus being the most prominent genus. The most abundant bacterial phyla were Proteobacteria and Bacteroidetes with most dominant families being Sphingobacteriaceae, Cytophagaceae, Flavobacteriaceae, Comamonadaceae, Planctomycetaceae, Nocardiaceae and Nostocaceae. These photobioreactors were also effective in reducing the overall amount of pathogens in wastewater compared to reactors with wastewater/tap water mixture. Functional analysis of the photobioreactor metagenomes revealed an increase in relative abundance genes related to photosynthesis, synthesis of vitamins important for auxotrophic algae and decrease in virulence and nitrogen metabolism subsystems in lake water reactors. The results of the study indicate that adding lake water to the wastewater-based photobioreactor leads to an altered bacterial community phylogenetic and functional structure that could be linked to higher algal biomass production, as well as to enhanced nutrient and pathogen reduction in these reactors.

  18. Co-gasification of biosolids with biomass: Thermogravimetric analysis and pilot scale study in a bubbling fluidized bed reactor.

    Science.gov (United States)

    Yu, Ming Ming; Masnadi, Mohammad S; Grace, John R; Bi, Xiaotao T; Lim, C Jim; Li, Yonghua

    2015-01-01

    This work studied the feasibility of co-gasification of biosolids with biomass as a means of disposal with energy recovery. The kinetics study at 800°C showed that biomass, such as switchgrass, could catalyze the reactions because switchgrass ash contained a high proportion of potassium, an excellent catalyst for gasification. However, biosolids could also inhibit gasification due to interaction between biomass alkali/alkaline earth metals and biosolids clay minerals. In the pilot scale experiments, increasing the proportion of biosolids in the feedstock affected gasification performance negatively. Syngas yield and char conversion decreased from 1.38 to 0.47m(3)/kg and 82-36% respectively as the biosolids proportion in the fuel increased from 0% to 100%. Over the same range, the tar content increased from 10.3 to 200g/m(3), while the ammonia concentration increased from 1660 to 19,200ppmv. No more than 25% biosolids in the fuel feed is recommended to maintain a reasonable gasification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Performance Assessment Of Local Biomass Powered Cereal Drier Used By Small-Scale Kenyan Farmers

    Directory of Open Access Journals (Sweden)

    Madaraka F. Mwema

    2015-05-01

    Full Text Available Abstract Recent studies have revealed that drying maize using biomass driers increase the quality of grains delays insect infestation mold and aflatoxin contamination in relation to direct sunlight drying. Most importantly biomass drying takes shorter time. It is therefore important to undertake performance of these driers to investigate the possibility of empirical control of such systems in remote areas. In this paper we present results of thermal performance of typical biomass-powered drier batch type. The results show that under natural convection temperature behavior within the drying chamber is unpredictable. However the use of exhaust fan forced convection gives predictable temperature distribution within the drying chamber. For burner shutter open at 50 and using maize cob as the fuel for forced convection the drying chamber attained a maximum temperature of 93amp730C after 28 minutes and minimum temperature of 69amp730C after 37 minutes in the lower tray tray 1. For burner shutter open at 100 the drying chamber attained a maximum temperature of 91amp730C after 41 minutes and minimum temperature of 67amp730C in tray 1. With burner 50 open tray 2 attained a maximum temperature of 62amp730C after 30 minutes and minimum temperature of 56amp730C after 40 minutes. With the burner 100 open tray 2 attained a maximum temperature of 61amp730C after 39 minutes and minimum temperature of 52amp730C after 52 minutes. From these results the optimal operating conditions of the burner operation were achieved when the shutter was open at 50. It took 76 minutes to dry 5kg of maize with about 0.8kg including dampness from rains moisture content in tray 1. It took 140 minutes to dry the same quantity and moisture content of maize in tray 2. These results show that it is possible to control empirically biomass cereal maize driers.

  20. Capacity study for solid biomass facilities - scenarios for supply and demand of solid biomass for electricity and heat generation in north west Europe

    NARCIS (Netherlands)

    Hoefnagels, E.T.A.; Junginger, H.M.; Faaij, A.P.C.

    2012-01-01

    Background: The growing awareness for climate change and security of supply leads to a increasing share of renewable energy in which biomass plays an important role. Especially in the European Union (EU-27), where member states have agreed on a binding target of a 20% renewable energy share of

  1. Scale study of direct synthesis of dimethyl ether from biomass synthesis gas.

    Science.gov (United States)

    Lv, Yongxing; Wang, Tiejun; Wu, Chuangzhi; Ma, Longlong; Zhou, Yi

    2009-01-01

    We investigated the synthesis of dimethyl ether (DME) from biomass synthesis gas using a kind of hybrid catalyst consisting of methanol and HZSM-5 zeolite in a fixed-bed reactor in a 100 ton/year pilot plant. The biomass synthesis gas was produced by oxygen-rich gasification of corn core in a two-stage fixed bed. The results showed that CO conversions reached 82.00% and 73.55%, the selectivities for DME were 73.95% and 69.73%, and the space-time yields were 124.28 kg m(-3) h(-1) and 203.80 kg m(-3) h(-1) when gas hourly space velocities were 650 h(-1) and 1200 h(-1), respectively. Deoxidation and tar removal from biomass synthesis gas was critical to the stable operation of the DME synthesis system. Using single-pass synthesis, the H(2)/CO ratio improved from 0.98-1.17 to 2.12-2.22. The yield of DME would be increased greatly if the exhaust was reused after removal of the CO(2).

  2. Relationships between aboveground biomass and plant cover at two spatial scales and their determinants in northern Tibetan grasslands.

    Science.gov (United States)

    Jiang, Yanbin; Zhang, Yangjian; Wu, Yupeng; Hu, Ronggui; Zhu, Juntao; Tao, Jian; Zhang, Tao

    2017-10-01

    The relationships between cover and AGB for the dominant and widely distributed alpine grasslands on the northern Tibetan Plateau is still not fully examined. The objectives of this study are to answer the following question: (1) How does aboveground biomass (AGB) of alpine grassland relate to plant cover at different spatial scales? (2) What are the major biotic and abiotic factors influencing on AGB-cover relationship? A community survey (species, cover, height, and abundance) was conducted within 1 m × 1 m plots in 70 sites along a precipitation gradient of 50-600 m. Ordinary linear regression was employed to examine AGB-cover relationships of both community and species levels at regional scale of entire grassland and landscape scale of alpine meadow, alpine steppe, and desert steppe. Hierarchical partitioning was employed to estimate independent contributions of biotic and abiotic factors to AGB and cover at both scales. Partial correlation analyses were used to discriminate the effects of biotic and abiotic factors on AGB-cover relationships at two spatial scales. AGB and community cover both exponentially increased along the precipitation gradient. At community level, AGB was positively and linearly correlated with cover for all grasslands except for alpine meadow. AGB was also linearly correlated with cover of species level at both regional and landscape scales. Contributions of biotic and abiotic factors to the relationship between AGB and cover significantly depended on spatial scales. Cover of cushions, forbs, legumes and sedges, species richness, MAP, and soil bulk density were important factors that influenced the AGB-cover relationship at either regional or landscape scale. This study indicated generally positive and linear relationships between AGB and cover are at both regional and landscape scales. Spatial scale may affect ranges of cover and modify the contribution of cover to AGB. AGB-cover relationships were influenced mainly by species

  3. Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part I. Influence of temperature, biomass species and solid heat carrier on the behaviour of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    C. Lievens; J. Yperman; J. Vangronsveld; R. Carleer [Hasselt University, Diepenbeek (Belgium). Laboratory of Applied Chemistry

    2008-08-15

    Presently, little or no information of implementing fast pyrolysis for looking into the potential valorisation of heavy metal contaminated biomass is available. Fast pyrolysis of heavy metal contaminated biomass (birch and sunflower), containing high amounts of Cd, Cu, Pb and Zn, resulting from phytoremediation, is investigated. The effect of the pyrolysis temperature (623, 673, 773 and 873 K) and the type of solid heat carrier (sand and fumed silica) on the distribution of the heavy metals in birch and sunflower pyrolysis fractions are studied. The goal of the set-up is 'concentrating' heavy metals in the ash/char fraction after thermal treatment, preventing them to be released in the condensable and/or volatile fractions. The knowledge of the behaviour of heavy metals affects directly future applications and valorisation of the pyrolysis products and thus contaminated biomass. They are indispensable for making and selecting the proper thermal conditions for their maximum recovery. In view of the future valorisation of these biomasses, the amounts of the pyrolysis fractions and the calorific values of the obtained liquid pyrolysis products, as a function of the pyrolysis temperature, are determined. 46 refs., 8 figs., 4 tabs.

  4. Clean heating with wood. An electrostatic separator reduces particulate matter emissions from biomass boilers; Sauber heizen mit Holz. Ein elektrostatischer Abscheider senkt die Feinstaub-Emissionen von Biomassekesseln

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Franz

    2016-08-01

    Despite considerable advances in firing technology, harmful particulate matter is produced when wood is combusted. Electrostatic precipitators, however, filter up to 90 per cent of particulate emissions from biomass boilers. These therefore enable wood burners to use a wider range of fuel and still meet the tightened requirements of Germany's 1st Ordinance on the Implementation of the Federal Immission Control Act. The major advantage: Both new and old heating plants can benefit from the new system.

  5. Flame dynamics of a meso-scale heat recirculating combustor

    Energy Technology Data Exchange (ETDEWEB)

    Vijayan, V.; Gupta, A.K. [Department of Mechanical Engineering, University of Maryland, College Park, MD 20742 (United States)

    2010-12-15

    The dynamics of premixed propane-air flame in a meso-scale ceramic combustor has been examined here. The flame characteristics in the combustor were examined by measuring the acoustic emissions and preheat temperatures together with high-speed cinematography. For the small-scale combustor, the volume to surface area ratio is small and hence the walls have significant effect on the global flame structure, flame location and flame dynamics. In addition to the flame-wall thermal coupling there is a coupling between flame and acoustics in the case of confined flames. Flame-wall thermal interactions lead to low frequency flame fluctuations ({proportional_to}100 Hz) depending upon the thermal response of the wall. However, the flame-acoustic interactions can result in a wide range of flame fluctuations ranging from few hundred Hz to few kHz. Wall temperature distribution is one of the factors that control the amount of reactant preheating which in turn effects the location of flame stabilization. Acoustic emission signals and high-speed flame imaging confirmed that for the present case flame-acoustic interactions have more significant effect on flame dynamics. Based on the acoustic emissions, five different flame regimes have been identified; whistling/harmonic mode, rich instability mode, lean instability mode, silent mode and pulsating flame mode. (author)

  6. Extension and application of a scaling technique for duplication of in-flight aerodynamic heat flux in ground test facilities

    NARCIS (Netherlands)

    Veraar, R.G.

    2009-01-01

    To enable direct experimental duplication of the inflight heat flux distribution on supersonic and hypersonic vehicles, an aerodynamic heating scaling technique has been developed. The scaling technique is based on the analytical equations for convective heat transfer for laminar and turbulent

  7. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    Science.gov (United States)

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated. © 2014 John Wiley & Sons Ltd.

  8. Study of heat treatment parameters for large-scale hydraulic steel gate track

    Directory of Open Access Journals (Sweden)

    Ping-zhou Cao

    2013-10-01

    Full Text Available In order to enhance external hardness and strength, a large-scale hydraulic gate track should go through heat treatment. The current design method of hydraulic gate wheels and tracks is based on Hertz contact linear elastic theory, and does not take into account the changes in mechanical properties of materials caused by heat treatment. In this study, the heat treatment parameters were designed and analyzed according to the bearing mechanisms of the wheel and track. The quenching process of the track was simulated by the ANSYS program, and the temperature variation, residual stress, and deformation were obtained and analyzed. The metallurgical structure field after heat treatment was predicted by the method based on time-temperature-transformation (TTT curves. The results show that the analysis method and designed track heat treatment process are feasible, and can provide a reference for practical projects.

  9. Experiments to investigate direct containment heating phenomena with scaled models of the Surry Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Blanchat, T.K.; Allen, M.D.; Pilch, M.M. [Sandia National Labs., Albuquerque, NM (United States); Nichols, R.T. [Ktech Corp., Albuquerque, NM (United States)

    1994-06-01

    The Containment Technology Test Facility (CTTF) and the Surtsey Test Facility at Sandia National Laboratories are used to perform scaled experiments that simulate High Pressure Melt Ejection accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive melt (thermite) is ejected by high-pressure steam into a scale model of a reactor cavity. Debris is entrained by the steam blowdown into a containment model where specific phenomena, such as the effect of subcompartment structures, prototypic air/steam/hydrogen atmospheres, and hydrogen generation and combustion, can be studied. Four Integral Effects Tests (IETs) have been performed with scale models of the Surry NPP to investigate DCH phenomena. The 1/61{sup th} scale Integral Effects Tests (IET-9, IET-10, and IET-11) were conducted in CTRF, which is a 1/6{sup th} scale model of the Surry reactor containment building (RCB). The 1/10{sup th} scale IET test (IET-12) was performed in the Surtsey vessel, which had been configured as a 1/10{sup th} scale Surry RCB. Scale models were constructed in each of the facilities of the Surry structures, including the reactor pressure vessel, reactor support skirt, control rod drive missile shield, biological shield wall, cavity, instrument tunnel, residual heat removal platform and heat exchangers, seal table room and seal table, operating deck, and crane wall. This report describes these experiments and gives the results.

  10. Micro-scale heat-exchangers for Joule-Thomson cooling.

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Andrew John

    2014-01-01

    This project focused on developing a micro-scale counter flow heat exchangers for Joule-Thomson cooling with the potential for both chip and wafer scale integration. This project is differentiated from previous work by focusing on planar, thin film micromachining instead of bulk materials. A process will be developed for fabricating all the devices mentioned above, allowing for highly integrated micro heat exchangers. The use of thin film dielectrics provides thermal isolation, increasing efficiency of the coolers compared to designs based on bulk materials, and it will allow for wafer-scale fabrication and integration. The process is intended to implement a CFHX as part of a Joule-Thomson cooling system for applications with heat loads less than 1mW. This report presents simulation results and investigation of a fabrication process for such devices.

  11. Controlled Cavitation for Scale-Free Heating, Gum Hydration and Emulsification in Food and Consumer Products

    Science.gov (United States)

    Mancosky, Douglas G.; Milly, Paul

    Cavitation is defined as the sudden formation and collapse of bubbles in liquid by means of a mechanical force. As bubbles rapidly form and collapse, pressurized shock waves, localized heating events and tremendous shearing forces occur. As microscopic cavitation bubbles are produced and collapse, shockwaves are given off into the liquid, which can result in heating and/or mixing, similar to ultrasound. These shockwaves can provide breakthrough benefits for the heating of liquids without scale buildup and/or the mixing of liquids with other liquids, gases or solids at the microscopic level to increase the efficiency of the reaction.

  12. Self-heating of dried industrial wastewater sludge: lab-scale investigation of supporting conditions.

    Science.gov (United States)

    Della Zassa, M; Biasin, A; Zerlottin, M; Refosco, D; Canu, P

    2013-06-01

    We studied the reactivity of dried sludge produced by treatment of wastewater, mainly from tanneries. The solids transformations have been first characterized with thermal analysis (TGA and DSC) proving that exothermic transformation takes place at fairly low temperature, before the total organic combustion that occurs in air above 400°C. The onset of low temperature reactions depends on the heating rate and it can be below 100°C at very small heating rate. Then, we reproducibly determined the conditions to trigger dried sludge self-heating at the laboratory scale, on samples in the 0.2-0.3 kg size. Thermal insulation, some aeration and addition of water are key factors. Mastering the self-heating at this scale allows more detailed investigations as well as manipulation of conditions, to understand its nature, course and remediation. Here we report proves and discussions on the role of air, water, particle size, porosity and biological activity, as well as proving that also dried sludge from similar sources lead to self-heating. Tests demonstrate that air and water are simultaneously required for significant self-heating to occur. They act in diverging directions, both triggering the onset of the reactions and damping the temperature rise, by supporting heat loss. The higher the O2 concentration, the higher the solids heating rate. More added water prolongs the exothermic phase. Further additions of water can reactivate the material. Water emphasizes the exothermic processes, but it is not sufficient to start it in an air-free atmosphere. The initial solid moisture concentration (between 8% and 15%) affects the onset of self-heating as intuitive. The sludge particles size strongly determines the strength and extent of the heat release, indicating that surface reactions are taking place. In pelletized particles, limitations to water and air permeability mitigates the reaction course. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Wallowa County Integrated Biomass Energy Center

    Energy Technology Data Exchange (ETDEWEB)

    Christoffersen, Nils [Wallowa Resources Community Solutions Inc., Wallowa, OR (United States)

    2014-05-02

    The Integrated Biomass Energy Center (IBEC) is an approximately 0.1 MW CHP integrated biorefinery in Northeastern Oregon which will demonstrate and validate small-scale combined heat and power from lignin intermediates/residues. IBEC will be co-located with feedstock suppliers and thermal and power customers for distributed generation. The project was developed by Wallowa Resources Community Solutions Inc.

  14. Large scale low cost production of submicrometric powder through biomass refinery

    Directory of Open Access Journals (Sweden)

    Daltro Garcia Pinatti

    2003-06-01

    Full Text Available Biomass Refinery (BR is a null pollution thermochemical sequential cracking of any biomass and some petrochemical products, which generates chemicals, liquid or solid fuels and inorganic submicrometric/nanometric powders (SM/NM such as ashes, silica, and carbon black. The processing route, powder characterisation and addition of some ashes to red clay resulting a grès-type ceramics will be presented. Rupture strengths of the vitrified ceramics were respectively 36 MPa for pure clay, 44 MPa for clay + 13.5% MOL ash (organic matter of municipal solid waste, 50 MPa for clay + 20% F+20% CL* ash (50% MOL + 50% wood and 42 MPa for clay + 40% feldspar (used for comparison. The reason why the BR-ashes are better than feldspar is due to their submicrometric and partially nanometric nature. The impact of BR-ash technology can be evaluated by its national potential production of 2 × 10(6 ton/year only from municipal solid waste (MSW compared to 350,000 ton/year of national consumption. The first BR is under installation in Lorena - SP, Brazil.

  15. Denitrification of high strength nitrate waste from a nuclear industry using acclimatized biomass in a pilot scale reactor.

    Science.gov (United States)

    Dhamole, Pradip B; Nair, Rashmi R; D'Souza, Stanislaus F; Pandit, Aniruddha B; Lele, S S

    2015-01-01

    This work investigates the performance of acclimatized biomass for denitrification of high strength nitrate waste (10,000 mg/L NO3) from a nuclear industry in a continuous laboratory scale (32 L) and pilot scale reactor (330 L) operated over a period of 4 and 5 months, respectively. Effect of substrate fluctuations (mainly C/NO3-N) on denitrification was studied in a laboratory scale reactor. Incomplete denitrification (95-96 %) was observed at low C/NO3-N (≤2), whereas at high C/NO3-N (≥2.25) led to ammonia formation. Ammonia production increased from 1 to 9 % with an increase in C/NO3-N from 2.25 to 6. Complete denitrification and no ammonia formation were observed at an optimum C/NO3-N of 2.0. Microbiological studies showed decrease in denitrifiers and increase in nitrite-oxidizing bacteria and ammonia-oxidizing bacteria at high C/NO3-N (≥2.25). Pilot scale studies were carried out with optimum C/NO3-N, and sustainability of the process was checked on the pilot scale for 5 months.

  16. Large Scale Deployment of Electric Vehicles (EVs) and Heat Pumps (HPs) in the Nordic Region

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei; Petersen, Pauli Fríðheim

    This report describes the study results of large scale deployment of electric vehicles (EVs) and heat pumps (HPs) in the Nordic countries of Denmark, Norway, Sweden and Finland, focusing on the demand profiles with high peneration of EVs and HPs in 2050......This report describes the study results of large scale deployment of electric vehicles (EVs) and heat pumps (HPs) in the Nordic countries of Denmark, Norway, Sweden and Finland, focusing on the demand profiles with high peneration of EVs and HPs in 2050...

  17. Heat transfer analysis of laboratory scale fast pyrolysis fluidised bed reactor

    Science.gov (United States)

    Jourabchi, Seyed Amirmostafa; Gan, Suyin; Ng, Hoon Kiat

    2017-04-01

    Heat transfer analysis of a fluidised bed with a bore diameter of 2.5 cm and a vertical length of 50 cm was investigated by using computational fluid dynamics (CFD) on FLUENT 15.0 educational version software. The Eulerian-Eulerian two-fluid granular model was used as the multiphase flow model to perform this simulation. A 2-D axisymmetric model was considered by using glass and stainless steel beads of 0.5 mm and 1.0 mm in diameters as the heat transfer medium to biomass. The Gidaspow model was used for the drag equation and the Gunn model was used in the interphase heat transfer coefficient determination. Heat transfer coefficient (HTC) of stainless steel beads shows to be approximately 3 times higher than that of the glass beads of the same size based on having higher thermal conductivity. At wall temperature of 500 K, stainless steel and glass beads can be fluidised by using nitrogen linear velocity of 0.7 and 0.3 m/s respectively. Under these optimum conditions, HTC reaches up to 7625 W/(m2.K) and 2900 W/(m2.K) for stainless steel and glass beads and their surface temperatures can reach up to 495 K and 480 K, respectively.

  18. Cost Scaling of a Real-World Exhaust Waste Heat Recovery Thermoelectric Generator: A Deeper Dive

    Science.gov (United States)

    Hendricks, Terry J.; Yee, Shannon; LeBlanc, Saniya

    2015-01-01

    Cost is equally important to power density or efficiency for the adoption of waste heat recovery thermoelectric generators (TEG) in many transportation and industrial energy recovery applications. In many cases the system design that minimizes cost (e.g., the $/W value) can be very different than the design that maximizes the system's efficiency or power density, and it is important to understand the relationship between those designs to optimize TEG performance-cost compromises. Expanding on recent cost analysis work and using more detailed system modeling, an enhanced cost scaling analysis of a waste heat recovery thermoelectric generator with more detailed, coupled treatment of the heat exchangers has been performed. In this analysis, the effect of the heat lost to the environment and updated relationships between the hot-side and cold-side conductances that maximize power output are considered. This coupled thermal and thermoelectric treatment of the exhaust waste heat recovery thermoelectric generator yields modified cost scaling and design optimization equations, which are now strongly dependent on the heat leakage fraction, exhaust mass flow rate, and heat exchanger effectiveness. This work shows that heat exchanger costs most often dominate the overall TE system costs, that it is extremely difficult to escape this regime, and in order to achieve TE system costs of $1/W it is necessary to achieve heat exchanger costs of $1/(W/K). Minimum TE system costs per watt generally coincide with maximum power points, but Preferred TE Design Regimes are identified where there is little cost penalty for moving into regions of higher efficiency and slightly lower power outputs. These regimes are closely tied to previously-identified low cost design regimes. This work shows that the optimum fill factor Fopt minimizing system costs decreases as heat losses increase, and increases as exhaust mass flow rate and heat exchanger effectiveness increase. These findings have

  19. Scaling Flux Tower Observations of Sensible Heat Flux Using Weighted Area-to-Area Regression Kriging

    Directory of Open Access Journals (Sweden)

    Maogui Hu

    2015-07-01

    Full Text Available Sensible heat flux (H plays an important role in characterizations of land surface water and heat balance. There are various types of H measurement methods that depend on observation scale, from local-area-scale eddy covariance (EC to regional-scale large aperture scintillometer (LAS and remote sensing (RS products. However, methods of converting one H scale to another to validate RS products are still open for question. A previous area-to-area regression kriging-based scaling method performed well in converting EC-scale H to LAS-scale H. However, the method does not consider the path-weighting function in the EC- to LAS-scale kriging with the regression residue, which inevitably brought about a bias estimation. In this study, a weighted area-to-area regression kriging (WATA RK model is proposed to convert EC-scale H to LAS-scale H. It involves path-weighting functions of EC and LAS source areas in both regression and area kriging stages. Results show that WATA RK outperforms traditional methods in most cases, improving estimation accuracy. The method is considered to provide an efficient validation of RS H flux products.

  20. Economics and engineering of large-scale algae biomass energy systems. Opportunity brief No. 11. Report No. 78-11. Revised edition

    Energy Technology Data Exchange (ETDEWEB)

    Doelling, N

    1978-05-01

    The goal of fuels from biomass is to investigate sources of energy on a scale that could provide around 5% of the national energy needs around 1990. The goal of this brief is to outline the current state of the art and the potential of aquatic plant biomass systems over the next 3 to 5 years, and to suggest industrial development and research opportunities. (DC)

  1. Exergetic and environmental impact assessments of an integrated organic Rankine cycle with a biomass combustor for combined cooling, heating and power production

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiman, F.A. [Carleton Univ., Ottawa, ON (Canada). Dept. of Mechanical and Aerospace Engineering; Hamdullahpur, F. [Waterloo Univ., ON (Canada). Dept. of Mechanical and Mechatronics Engineering; Dincer, I. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

    2010-07-01

    A trigeneration thermal system produces cooling, heating and power from the same source. In trigeneration plants, waste heat is used for heating and cooling. In this paper, exergetic and environmental impact analyses of a trigeneration system based on an integrated organic Rankine cycle (ORC) with a biomass combustor were conducted. The analyses were extended to include electrical-power, cooling-cogeneration and heating-cogeneration cases. The objective was to understand the working phenomena of the proposed system, and identify and quantify the sources of the irreversibilities in the system associated with each component. The environmental impact of the proposed system was also quantified. The exergy efficiency, exergy destruction rate and carbon dioxide (CO{sub 2}) emissions were examined under the variations of pump inlet temperature and turbine inlet pressure. The results showed that exergy efficiency increased to 27 per cent when trigeneration was used as compared 11 per cent when the electrical power system was used. The main two sources of exergy destruction were the biomass combustor and the ORC evaporator. Emissions of CO{sub 2} were much higher in the case of the the electrical-power system compared to the trigeneration system. 11 refs., 1 tab., 8 figs.

  2. Synoptic-to-planetary scale wind variability enhances phytoplankton biomass at ocean fronts

    Science.gov (United States)

    Whitt, D. B.; Taylor, J. R.; Lévy, M.

    2017-06-01

    In nutrient-limited conditions, phytoplankton growth at fronts is enhanced by winds, which drive upward nutrient fluxes via enhanced turbulent mixing and upwelling. Hence, depth-integrated phytoplankton biomass can be 10 times greater at isolated fronts. Using theory and two-dimensional simulations with a coupled physical-biogeochemical ocean model, this paper builds conceptual understanding of the physical processes driving upward nutrient fluxes at fronts forced by unsteady winds with timescales of 4-16 days. The largest vertical nutrient fluxes occur when the surface mixing layer penetrates the nutricline, which fuels phytoplankton in the mixed layer. At a front, mixed layer deepening depends on the magnitude and direction of the wind stress, cross-front variations in buoyancy and velocity at the surface, and potential vorticity at the base of the mixed layer, which itself depends on past wind events. Consequently, mixing layers are deeper and more intermittent in time at fronts than outside fronts. Moreover, mixing can decouple in time from the wind stress, even without other sources of physical variability. Wind-driven upwelling also enhances depth-integrated phytoplankton biomass at fronts; when the mixed layer remains shallower than the nutricline, this results in enhanced subsurface phytoplankton. Oscillatory along-front winds induce both oscillatory and mean upwelling. The mean effect of oscillatory vertical motion is to transiently increase subsurface phytoplankton over days to weeks, whereas slower mean upwelling sustains this increase over weeks to months. Taken together, these results emphasize that wind-driven phytoplankton growth is both spatially and temporally intermittent and depends on a diverse combination of physical processes.

  3. Quantify the continuous dependence of SST-turbulent heat flux relationship on spatial scales

    Science.gov (United States)

    Li, Furong; Sang, Huiyan; Jing, Zhao

    2017-06-01

    Relationship among different quantities usually changes in the time, spatial, and spectral domains due to the complicated dynamics in the geosystem. In this study, we propose a general statistical modeling approach to address this problem and apply the approach to evaluating the continuous dependence of relationship between sea surface temperature (SST) and turbulent heat flux (T-Q relationship) on spatial scales. In the Kuroshio extension region, it is found that the turbulent heat flux (defined positive upward) anomalies are positively correlated to SST anomalies at scales ranging from 150 km to 4000 km. The T-Q relationship stays stable at mesoscales (<1000 km) with a regression coefficient α of 26 W/(m2K). However, its value decreases rapidly as scales further increase. In addition, α exhibits a pronounced seasonal cycle with coherent phase at all the scales. The largest and smallest values occur in winter and summer, respectively.

  4. A metabolic and body-size scaling framework for parasite within-host abundance, biomass, and energy flux.

    Science.gov (United States)

    Hechinger, Ryan F

    2013-08-01

    Energetics may provide a useful currency for studying the ecology of parasite assemblages within individual hosts. Parasite assemblages may also provide powerful models to study general principles of ecological energetics. Yet there has been little ecological research on parasite-host energetics, probably due to methodological difficulties. However, the scaling relationships of individual metabolic rate with body or cell size and temperature may permit us to tackle the energetics of parasite assemblages in hosts. This article offers the foundations and initial testing of a metabolic theory of ecology (MTE) framework for parasites in hosts. I first provide equations to estimate energetic flux through observed parasite assemblages. I then develop metabolic scaling theory for parasite abundance, energetics, and biomass in individual hosts. In contrast to previous efforts, the theory factors in both host and parasite metabolic scaling, how parasites use host space, and whether energy or space dictates carrying capacity. Empirical tests indicate that host energetic flux can set parasite carrying capacity, which decreases as predicted considering the scaling of host and parasite metabolic rates. The theory and results also highlight that the phenomenon of "energetic equivalence" is not an assumption of MTE but a possible outcome contingent on how species partition resources. Hence, applying MTE to parasites can lend mechanistic, quantitative, predictive insight into the nature of parasitism and can inform general ecological theory.

  5. The Tectonics Model of Coronal Heating: Unsteady Dynamics and Scaling in Statistical Steady State

    Science.gov (United States)

    Ng, C. S.; Lin, L.; Bhattacharjee, A.

    2009-11-01

    The tectonics model of coronal heating, proposed by Priest et al. [Astrophys. J., 576, 533 (2002)] envisions coronal heating caused by a hierarchy of current sheets produced by the movement of a myriad of flux elements in the magnetic carpet covering the Sun. We have recently obtained new scaling results in two dimensions (2D) suggesting that the heating rate becomes independent of resistivity in a statistical steady state [C. S. Ng and A. Bhattacharjee, Astrophys. J., 675, 899 (2008)]. Our numerical work has now been extended to 3D. Random photospheric footpoint motion is applied to obtain converged average coronal heating rates. In the large Lundquist number limit, we find that the heating rate is independent of the Lundquist number, with average magnetic energy saturating at a constant level due to the formation of strong current layers and subsequent disruptions. In this talk, we will present our latest numerical results from large-scale 3D simulations, and discuss differences with previous scaling laws.

  6. The Scaling of Loss Pathways and Heat Transfer in Small Scale Internal Combustion Engines

    Science.gov (United States)

    2016-09-16

    deflection, measured on a Wheatstone bridge.  Optical: a fiber optic technique is used to detect the deflection of a diaphragm.  Piezo electric: a...maximum amplitude of pressure oscillations relative to the pressure trace with the oscillations smoothed or removed with averaging or filtering ...cylinder. Initially, ceramic cylinder coatings were tested and found to have little benefit. Directly heating the head caused warping of some components

  7. Potential of duckweed in the conversion of wastewater nutrients to valuable biomass: a pilot-scale comparison with water hyacinth.

    Science.gov (United States)

    Zhao, Yonggui; Fang, Yang; Jin, Yanling; Huang, Jun; Bao, Shu; Fu, Tian; He, Zhiming; Wang, Feng; Zhao, Hai

    2014-07-01

    The application potential of duckweed (Lemna japonica 0234) and water hyacinth (Eichhornia crassipes) were compared in two pilot-scale wastewater treatment systems for more than one year. The results indicated duckweed had the same total nitrogen (TN) recovery rate as water hyacinth (0.4 g/m(2)/d) and a slightly lower total phosphorus (TP) recovery rate (approximately 0.1g/m(2)/d) even though its biomass production was half that of water hyacinth. The higher content of crude protein (33.34%), amino acids (25.80%), starch (40.19%), phosphorus (1.24%), flavonoids (2.91%) and lower fiber content provided duckweed with more advantages in resource utilization. Additionally, microbial community discovered by 454 pyrosequencing indicated that less nitrifying bacteria and more nitrogen-fixing bacteria in rhizosphere of duckweed provided it with higher nitrogen recovery efficiency (60%) than water hyacinth (47%). Under the presented condition, duckweed has more application advantages than water hyacinth because it more effectively converted the wastewater nutrients into valuable biomass. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Emissions from small-scale combustion of biomass fuels - extensive quantification and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Christoffer; Nordin, Anders; Oehman, Marcus; Bostroem, Dan [Umeaa Univ. (Sweden). Energy Technology and Thermal Process Chemistry; Westerholm, Roger [Stockholm Univ. (Sweden). Arrhenius Laboratory

    2005-02-01

    This work was a part of the Swedish national research program concerning emissions and air quality with the sub-programme concerning biomass, health and environment ('Biobraenslen, Haelsa, Miljoe' - BHM). The main objective of the work was to systematically determine the quantities and characteristics of gaseous and particulate emissions from combustion in residential wood log and biomass fuel pellet appliances and report emission factors for the most important emission components. The specific focus was on present commercial wood and pellet stoves as well as to illustrate the potentials for future technology development. The work was divided in different subprojects; 1) a literature review of health effects of ambient wood smoke, 2) design and evaluation of an emission dilution sampling set-up, 3) a study of the effects of combustion conditions on the emission formation and characteristics and illustrate the potential for emission minimization during pellets combustion, 4) a study of the inorganic characteristics of particulate matter during combustion of different pelletized woody raw materials and finally 5) an extensive experimental characterization and quantification of gaseous and particulate emissions from residential wood log and pellet stoves. From the initial literature search, nine relevant health studies were identified, all focused on effects of short-term exposure. Substantial quantitative information was only found for acute asthma in relation to PM{sub 10}. In comparison with the general estimations for ambient PM and adverse health effects, the relative risks were even stronger in the studies where residential wood combustion was considered as a major PM source. However, the importance of other particle properties than mass concentration, like chemical composition, particle size and number concentration remain to be elucidated. A whole flow dilution sampling set-up for residential biomass fired appliances was designed, constructed and

  9. Emissions from small-scale combustion of biomass fuels - extensive quantification and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Christoffer; Nordin, Anders; Oehman, Marcus; Bostroem, Dan [Umeaa Univ. (Sweden). Energy Technology and Thermal Process Chemistry; Westerholm, Roger [Stockholm Univ., Arrhenius Laboratory (Sweden). Analytical Chemistry

    2005-02-01

    This work was a part of the Swedish national research program concerning emissions and air quality with the sub-programme concerning biomass, health and environment - BHM. The main objective of the work was to systematically determine the quantities and characteristics of gaseous and particulate emissions from combustion in residential wood log and biomass fuel pellet appliances and report emission factors for the most important emission components. The specific focus was on present commercial wood and pellet stoves as well as to illustrate the potentials for future technology development. The work was divided in different subprojects; 1) a literature review of health effects of ambient wood smoke, 2) design and evaluation of an emission dilution sampling set-up, 3) a study of the effects of combustion conditions on the emission formation and characteristics and illustrate the potential for emission minimization during pellets combustion, 4) a study of the inorganic characteristics of particulate matter during combustion of different pelletized woody raw materials and finally 5) an extensive experimental characterization and quantification of gaseous and particulate emissions from residential wood log and pellet stoves. From the initial literature search, nine relevant health studies were identified, all focused on effects of short-term exposure. Substantial quantitative information was only found for acute asthma in relation to PM10. In comparison with the general estimations for ambient PM and adverse health effects, the relative risks were even stronger in the studies where residential wood combustion was considered as a major PM source. However, the importance of other particle properties than mass concentration, like chemical composition, particle size and number concentration remain to be elucidated. A whole flow dilution sampling set-up for residential biomass fired appliances was designed, constructed and evaluated concerning the effects of sampling

  10. Modeling heat dominated electric breakdown in air, with adaptivity to electron or ion time scales

    Science.gov (United States)

    Agnihotri, A.; Hundsdorfer, W.; Ebert, U.

    2017-09-01

    We model heat dominated electrical breakdown in air in a short planar gap. We couple the discharge dynamics in fluid approximation with the hydrodynamic motion of the air heated by the discharge. To be computationally efficient, we derive a reduced model on the ion time scale, and we switch between the full model on the electron time scale and the reduced model. We observe an ion pulse reaching the cathode, releasing electrons by secondary emission, and these electrons create another ion pulse. These cycles of ion pulses might lead to electrical breakdown. This breakdown is driven by Ohmic heating, thermal shocks and induced pressure waves, rather than by the streamer mechanism of local field enhancement at the streamer tip.

  11. Scale analysis and integral approximation applied to heat and mass transfer in packed beds

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2008-01-01

    In this paper, we apply two mathematical tools for the analysis of models describing heat and mass transfer in dispersed systems, namely scale analysis and integral approximation. The particular model investigated is a 1-D model describing the cooling of packed beds of fresh agricultural produce

  12. Is Earth-based scaling a valid procedure for calculating heat flows for Mars?

    Science.gov (United States)

    Ruiz, Javier; Williams, Jean-Pierre; Dohm, James M.; Fernández, Carlos; López, Valle

    2013-09-01

    Heat flow is a very important parameter for constraining the thermal evolution of a planetary body. Several procedures for calculating heat flows for Mars from geophysical or geological proxies have been used, which are valid for the time when the structures used as indicators were formed. The more common procedures are based on estimates of lithospheric strength (the effective elastic thickness of the lithosphere or the depth to the brittle-ductile transition). On the other hand, several works by Kargel and co-workers have estimated martian heat flows from scaling the present-day terrestrial heat flow to Mars, but the so-obtained values are much higher than those deduced from lithospheric strength. In order to explain the discrepancy, a recent paper by Rodriguez et al. (Rodriguez, J.A.P., Kargel, J.S., Tanaka, K.L., Crown, D.A., Berman, D.C., Fairén, A.G., Baker, V.R., Furfaro, R., Candelaria, P., Sasaki, S. [2011]. Icarus 213, 150-194) criticized the heat flow calculations for ancient Mars presented by Ruiz et al. (Ruiz, J., Williams, J.-P., Dohm, J.M., Fernández, C., López, V. [2009]. Icarus 207, 631-637) and other studies calculating ancient martian heat flows from lithospheric strength estimates, and casted doubts on the validity of the results obtained by these works. Here however we demonstrate that the discrepancy is due to computational and conceptual errors made by Kargel and co-workers, and we conclude that the scaling from terrestrial heat flow values is not a valid procedure for estimating reliable heat flows for Mars.

  13. L-Band SAR Backscatter Related to Forest Cover, Height and Aboveground Biomass at Multiple Spatial Scales across Denmark

    Directory of Open Access Journals (Sweden)

    Neha P. Joshi

    2015-04-01

    Full Text Available Mapping forest aboveground biomass (AGB using satellite data is an important task, particularly for reporting of carbon stocks and changes under climate change legislation. It is known that AGB can be mapped using synthetic aperture radar (SAR, but relationships between AGB and radar backscatter may be confounded by variations in biophysical forest structure (density, height or cover fraction and differences in the resolution of satellite and ground data. Here, we attempt to quantify the effect of these factors by relating L-band ALOS PALSAR HV backscatter and unique country-wide LiDAR-derived maps of vegetation penetrability, height and AGB over Denmark at different spatial scales (50 m to 500 m. Trends in the relations indicate that, first, AGB retrieval accuracy from SAR improves most in mapping at 100-m scale instead of 50 m, and improvements are negligible beyond 250 m. Relative errors (bias and root mean squared error decrease particularly for high AGB values (\\(>\\110 Mg ha\\(^{-1}\\ at coarse scales, and hence, coarse-scale mapping (\\(\\ge\\150 m may be most suited for areas with high AGB. Second, SAR backscatter and a LiDAR-derived measure of fractional forest cover were found to have a strong linear relation (R\\(^2\\ = 0.79 at 250-m scale. In areas of high fractional forest cover, there is a slight decline in backscatter as AGB increases, indicating signal attenuation. The two results demonstrate that accounting for spatial scale and variations in forest structure, such as cover fraction, will greatly benefit establishing adequate plot-sizes for SAR calibration and the accuracy of derived AGB maps.

  14. Improving Large-scale Biomass Burning Carbon Consumption and Emissions Estimates in the Former Soviet Union based on Fire Weather

    Science.gov (United States)

    Westberg, D. J.; Soja, A. J.; Tchebakova, N.; Parfenova, E. I.; Kukavskaya, E.; de Groot, B.; McRae, D.; Conard, S. G.; Stackhouse, P. W., Jr.

    2012-12-01

    Estimating the amount of biomass burned during fire events is challenging, particularly in remote and diverse regions, like those of the Former Soviet Union (FSU). Historically, we have typically assumed 25 tons of carbon per hectare (tC/ha) is emitted, however depending on the ecosystem and severity, biomass burning emissions can range from 2 to 75 tC/ha. Ecosystems in the FSU span from the tundra through the taiga to the forest-steppe, steppe and desserts and include the extensive West Siberian lowlands, permafrost-lain forests and agricultural lands. Excluding this landscape disparity results in inaccurate emissions estimates and incorrect assumptions in the transport of these emissions. In this work, we present emissions based on a hybrid ecosystem map and explicit estimates of fuel that consider the depth of burning based on the Canadian Forest Fire Weather Index System. Specifically, the ecosystem map is a fusion of satellite-based data, a detailed ecosystem map and Alexeyev and Birdsey carbon storage data, which is used to build carbon databases that include the forest overstory and understory, litter, peatlands and soil organic material for the FSU. We provide a range of potential carbon consumption estimates for low- to high-severity fires across the FSU that can be used with fire weather indices to more accurately estimate fire emissions. These data can be incorporated at ecoregion and administrative territory scales and are optimized for use in large-scale Chemical Transport Models. Additionally, paired with future climate scenarios and ecoregion cover, these carbon consumption data can be used to estimate potential emissions.

  15. Pore-Scale Simulations Of Flow And Heat Transport In Saturated Permeable Media

    Science.gov (United States)

    Zegers, G. R., Sr.; Herrera, P. A.

    2015-12-01

    The study of heat transport in porous media is important for applications such as the use of temperature as environmental tracer, geothermal energy, fuel cells, etc. In recent years, there have been several advances in computational techniques that have allowed to investigate different processes in porous media at the pore-scale through detailed numerical simulations that considered synthetic porous media formed by regular grains and pore bodies arranged in different geometrical configurations. The main objective of this research is to investigate the influence of pore configurations on flow velocity and heat transport in 2D saturated porous media. We use OpenFOAM to solve flow and heat transport equations at the pore-scale. We performed detailed pore-scale numerical simulations in synthetic 2D porous media generated from regularly placed and randomly distributed circular solid grains. For each geometrical configuration we performed numerical simulations to compute the flow field in order to calculate properties such as as tortuosity, mean velocity and hydraulic conductivity, and to identify Lagrangian coherent structures to charaterize the velocity fields. We then perform heat transport simulations to relate the properties of the velocity fields and the main heat transport mechanisms. The analysis of the simulations results showed that in all the simulated configurations effective flow properties become valid at scales of 10 to 15 pore bodies. For the same porosity and boundary conditions we obtained that as expected tortuosity in the random structure is higher than in the regular configurations, while hydraulic conductivity is smaller for the random case. The results of heat transport simulations show significant differences in temperature distribution for the regular and random pore structures. For the simulated boundary and initial conditions, heat transport is more efficient in the random structure than in the regular geometry. This result indicates that the

  16. Design and construction of a hybrid system of heating air by combustion of biomass and solar radiation, using phase change material (PCM as a source of thermal storage, for cassava drying

    Directory of Open Access Journals (Sweden)

    Ramiro Torres-Gallo

    2017-05-01

    Full Text Available This study consisted of designing, building and validation a hybrid system of heating air by combustion of biomass and solar radiation, using phase change material (PCM as a thermal storage source, for cassava drying, a small scale. The dryer consists of a centrifugal fan, two solar collectors, a fuel burner solid (rice husk and a tray dryer. System validation was performed drying up Yucca. The PCM allowed to follow the drying process, even when the solar radiation was below 116,22 ± 31,94 W / m2, being able to maintain drying air temperatures in the two solar collectors at 46 ± 4, 29 ° C and 51 ± 4.08 ° C for an additional 45 min. The drying time was 10 h and 45 min, the efficiency of the solar collectors was 43.91 % and the rice husk burner of 36.72 %.

  17. The world scale biomass controlled by men: population feeding, greenhouse effect impacts,...; Les biomasses controlees par l'homme a l'echelle mondiale: alimentation de la population, impacts sur l'effet de serre,...

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, J.F. [Ecole Nationale Superieure de Mecanique et d' Aerotechnique (ENSMA-LEPT), Lab. Energetique et Phenomenes de Transfert, 33 - Talence (France)

    2001-07-01

    This paper deals with the interaction between two problems: the management of natural energy resources of the continental biomass, and the additional greenhouse effect. These problems are approached in a 'general energy' way in order to propose for the main partitions of the terrestrial biomass system an evaluation of the energy fluxes at any step, from the solar radiation conversion to the exploitation of the final products: supply of vegetal and animal products, materials, etc.. This method is used to analyze at the global scale the possible implications of the biomass exploitation on the carbon cycle. Two aspects have to be considered: the storage of CO{sub 2} and the role of CH{sub 4}. (J.S.)

  18. Micro-Cogeneration Incl. The Conversion of Chemical Energy of Biomass to Electric Energy and the Low Potential Heat

    Science.gov (United States)

    Huzvar, Jozef; Kapjor, Andrej

    2011-06-01

    This article deals with combined production of heat and electricity for small premises, such as households, where energy consumption is around few kilowatts. This proposal of micro co-generation unit uses as a heat source an automatic burner for combustion of wood pellets. Construction of an equipment for the heat transport can be designed using different basic ways of heat transfer. Electricity is produced by the two-stroke steam engine and the generator.

  19. Preparation for full scale demonstration of an air staged gasifier plant. Technical project development; For combined heat and power production with wood chips; Forberedelse til fuldskala demonstration af trinopdelt forgasningsanlaeg. Teknisk projektudvikling. Delrapport

    Energy Technology Data Exchange (ETDEWEB)

    Houmann Jakobsen, H.

    2011-04-15

    The project has aimed to further develop the technology for staged biomass gasification and establish an organizational and financial model to ensure that the technology can be introduced on the market. This report describes the technique in an upcoming demonstration plant. A complete planning and design of a demonstration plant with a capacity of 300 kW electric power and 700 kW heat was prepared. That is four times more than the pilot plant at Graested District Heating (Castor plant) can produce. A full scale demonstration plant with bio-gasification technology for wood chips will be established and put into operation in 2012. (ln)

  20. Investigation of small scale solar concentration parabolic dish with heat storage: (low to medium temperature application

    Energy Technology Data Exchange (ETDEWEB)

    Madessa, Habtamu Bayera

    2012-07-01

    This PhD thesis focuses on the development and testing of a small scale concentrating parabolic dish with heat storage for low to medium temperature applications. The system consists of a parabolic dish solar concentrator that concentrates solar radiation, a fibrous mat solar absorber that captures concentrated solar rays and converts them to thermal energy and a packed bed with pebble rock as a thermal energy storage unit. This research has targeted several issues in which there is a lack of knowledge on small scale concentrating solar energy technologies, with the work summarized in eight papers. Paper 1 concerns experimental measurement of the dynamic temperature profiles along a rock bed heat storage unit during thermal charging and degradation. The study examined both finned and non-finned types of rock bed storages. The effects of the long fins. which are incorporated to transport heat from the bottom to the top surface of the heat storage, were investigated in relation to temperature distribution. As an extension of Paper 1, the performance of a rock bed fitted with long fins was studied as a heat storage unit and a cooking device. The bed charging efficiency, as well as the capacity to store thermal energy and extract heat for boiling of water was discussed. Paper 3 describes the implemention of a 1D numerical model in the MATLAB environment to simulate the transient temperature profiles of rock bed heat storage units. Conservation equations were formulated for the air, rock pebble and fins. The equations were solved on a staggered grid, and the model predicts the experimental results reasonably well. The thesis also investigates two types of volumetric solar absorbers (a fibrous wire mesh and a ceramic) that could be incorporated with a small scale solar concentrating parabolic dish system. Both the fibrous mesh and ceramic type absorbers display a better performance, as discussed in Paper 4. Another contribution of the PhD work is to investigate a 1D sun

  1. The Techno-Economics of Small-Scale Residential Heating in Low Carbon Futures

    Directory of Open Access Journals (Sweden)

    Avinash Vijay

    2017-11-01

    Full Text Available Existing studies that consider the techno-economics of residential heating systems typically focus on their performance within present-day energy systems. However, the energy system within which these technologies operate will need to change radically if climate change mitigation is to be achieved. This article addresses this problem by modelling small-scale heating techno-economics in the context of significant electricity system decarbonisation. The current electricity market price regime based on short run marginal costs is seen to provide a very weak investment signal for electricity system investors, so an electricity price regime based on long run marginal energy costs is also considered, using a case study of the UK in 2035. The economic case for conventional boilers remains stronger in most dwelling types. The exception to this is for dwellings with high annual heat demand. Sensitivity studies demonstrate the impact of factors such as price of natural gas, carbon intensity of the central grid and thermodynamic performance. Fuel cell micro combined heat and power shows most potential under the long run electricity price regime, and heat pumps under the short run electricity price regime. This difference highlights the importance of future electricity market structure on consumer choice of heating systems in the future.

  2. TG-FTIR characterization of coal and biomass single fuels and blends under slow heating rate conditions: Partitioning of the fuel-bound nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Di Nola, G.; de Jong, W.; Spliethoff, H. [Energy Technology Section, Process and Energy Department, Faculty 3me, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands)

    2010-01-15

    The devolatilization behavior of a bituminous coal and different biomass fuels currently applied in the Dutch power sector for co-firing was experimentally investigated. The volatile composition during single fuel pyrolysis as well as during co-pyrolysis was studied using TG-FTIR characterization with the focus on the release patterns and quantitative analysis of the gaseous bound nitrogen species. It was shown that all investigated biomass fuels present more or less similar pyrolysis behavior, with a maximum weight loss between 300 and 380 C. Woody and agricultural biomass materials show higher devolatilization rates than animal waste. When comparing different fuels, the percentage of fuel-bound nitrogen converted to volatile bound-N species (NH{sub 3}, HCN, HNCO) does not correlate with the initial fuel-N content. Biomass pyrolysis resulted in higher volatile-N yields than coal, which potentially indicates that NO{sub x} control during co-firing might be favored. No significant interactions occurred during the pyrolysis of coal/biomass blends at conditions typical of TG analysis (slow heating rate). Evolved gas analysis of volatile species confirmed the absence of mutual interactions during woody biomass co-pyrolysis. However, non-additive behavior of selected gas species was found during slaughter and poultry litter co-pyrolysis. Higher CH{sub 4} yields between 450 and 750 C and higher ammonia and CO yields between 550 and 900 C were measured. Such a result is likely to be attributed to catalytic effects of alkali and alkaline earth metals present in high quantity in animal waste ash. The fact that the co-pyrolysis of woody and agricultural biomass is well modeled by simple addition of the individual behavior of its components permits to predict the mixture's behavior based on experimental data available for single fuels. On the other hand, animal waste co-pyrolysis presented in some cases synergistic effects in gas products although additive behavior

  3. Scaling laws of turbulence and heating of fast solar wind: the role of density fluctuations.

    Science.gov (United States)

    Carbone, V; Marino, R; Sorriso-Valvo, L; Noullez, A; Bruno, R

    2009-08-07

    Incompressible and isotropic magnetohydrodynamic turbulence in plasmas can be described by an exact relation for the energy flux through the scales. This Yaglom-like scaling law has been recently observed in the solar wind above the solar poles observed by the Ulysses spacecraft, where the turbulence is in an Alfvénic state. An analogous phenomenological scaling law, suitably modified to take into account compressible fluctuations, is observed more frequently in the same data set. Large-scale density fluctuations, despite their low amplitude, thus play a crucial role in the basic scaling properties of turbulence. The turbulent cascade rate in the compressive case can, moreover, supply the energy dissipation needed to account for the local heating of the nonadiabatic solar wind.

  4. Scaling Laws of Turbulence and Heating of Fast SolarWind: The Role of Density Fluctuations

    CERN Document Server

    Carbone, V; Sorriso-Valvo, L; Noullez, A; Bruno, R

    2010-01-01

    Incompressible and isotropic magnetohydrodynamic turbulence in plasms can be described by an exact relation for the energy flux through the scales. This Yaglom-like scaling law has been recently observed in the solar wind above the solar poles observed by the Ulysses spacecraft, where the turbulence is in an Alfv\\'enic state. An analogous phenomenological scaling law, suitably modified to take into account compressible fluctuations, is observed more frequently in the same dataset. Large scale density fluctuations, despite their low amplitude, play thus a crucial role in the basic scaling properties of turbulence. The turbulent cascade rate in the compressive case can moreover supply the energy dissipation needed to account for the local heating of the non-adiabatic solar wind.

  5. Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling

    Science.gov (United States)

    Lawson, Sarah J.; Cope, Martin; Lee, Sunhee; Galbally, Ian E.; Ristovski, Zoran; Keywood, Melita D.

    2017-10-01

    We have tested the ability of a high-resolution chemical transport model (CTM) to reproduce biomass burning (BB) plume strikes and ozone (O3) enhancements observed at Cape Grim in Tasmania, Australia, from the Robbins Island fire. The CTM has also been used to explore the contribution of near-field BB emissions and background sources to O3 observations under conditions of complex meteorology. Using atmospheric observations, we have tested model sensitivity to meteorology, BB emission factors (EFs) corresponding to low, medium, and high modified combustion efficiency (MCE), and spatial variability. The use of two different meteorological models (TAPM-CTM and CCAM-CTM) varied the first (BB1) plume strike time by up to 15 h and the duration of impact between 12 and 36 h, and it varied the second (BB2) plume duration between 50 and 57 h. Meteorology also had a large impact on simulated O3, with one model (TAPM-CTM) simulating four periods of O3 enhancement, while the other model (CCAM) simulating only one period. Varying the BB EFs, which in turn varied the non-methane organic compound (NMOC) / oxides of nitrogen (NOx) ratio, had a strongly non-linear impact on simulated O3 concentration, with either destruction or production of O3 predicted in different simulations. As shown in previous work (Lawson et al., 2015), minor rainfall events have the potential to significantly alter EF due to changes in combustion processes. Models that assume fixed EF for O3 precursor species in an environment with temporally or spatially variable EF may be unable to simulate the behaviour of important species such as O3. TAPM-CTM is used to further explore the contribution of the Robbins Island fire to the observed O3 enhancements during BB1 and BB2. Overall, TAPM-CTM suggests that the dominant source of O3 observed at Cape Grim was aged urban air (age = 2 days), with a contribution of O3 formed from local BB emissions. This work shows the importance of assessing model sensitivity to

  6. Fossil fuel savings, carbon emission reduction and economic attractiveness of medium-scale integrated biomass gasification combined cycle cogeneration plants

    Directory of Open Access Journals (Sweden)

    Kalina Jacek

    2012-01-01

    Full Text Available The paper theoretically investigates the system made up of fluidized bed gasifier, SGT-100 gas turbine and bottoming steam cycle. Different configurations of the combined cycle plant are examined. A comparison is made between systems with producer gas (PG and natural gas (NG fired turbine. Supplementary firing of the PG in a heat recovery steam generator is also taken into account. The performance of the gas turbine is investigated using in-house built Engineering Equation Solver model. Steam cycle is modeled using GateCycleTM simulation software. The results are compared in terms of electric energy generation efficiency, CO2 emission and fossil fuel energy savings. Finally there is performed an economic analysis of a sample project. The results show relatively good performance in the both alternative configurations at different rates of supplementary firing. Furthermore, positive values of economic indices were obtained. [Acknowledgements. This work was carried out within the frame of research project no. N N513 004036, titled: Analysis and optimization of distributed energy conversion plants integrated with gasification of biomass. The project is financed by the Polish Ministry of Science.

  7. Long term (2050) projections of techno-economic performance of large-scale heating and cooling in the EU

    OpenAIRE

    GROSSE ROBERT; CHRISTOPHER BINDER; STEFAN WÖLL; GEYER ROMAN; ROBBI STEFFEN

    2017-01-01

    The following study provides data and projections for large-scale District Heating (DH) technologies including an outlook till 2050 and regional differences. The study complements a study for small-scale technologies applicable to residential and tertiary sector. The data set can be downloaded here http://data.jrc.cec.eu.int/dataset/jrc-etri-techno-economics-larger-heating-cooling-technologies-2017

  8. The effects of torrefaction on compositions of bio-oil and syngas from biomass pyrolysis by microwave heating.

    Science.gov (United States)

    Ren, Shoujie; Lei, Hanwu; Wang, Lu; Bu, Quan; Chen, Shulin; Wu, Joan; Julson, James; Ruan, Roger

    2013-05-01

    Microwave pyrolysis of torrefied Douglas fir sawdust pellet was investigated to determine the effects of torrefaction on the biofuel production. Compared to the pyrolysis of raw biomass, the increased concentrations of phenols and sugars and reduced concentrations of guaiacols and furans were obtained from pyrolysis of torrefied biomass, indicating that torrefaction as a pretreatment favored the phenols and sugars production. Additionally, about 3.21-7.50 area% hydrocarbons and the reduced concentration of organic acids were obtained from pyrolysis of torrefied biomass. Torrefaction also altered the compositions of syngas by reducing CO2 and increasing H2 and CH4. The syngas was rich in H2, CH4, and CO implying that the syngas quality was significantly improved by torrefaction process. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Generalized Scaling of Urban Heat Island Effect and Its Applications for Energy Consumption and Renewable Energy

    Directory of Open Access Journals (Sweden)

    T.-W. Lee

    2014-01-01

    Full Text Available In previous work from this laboratory, it has been found that the urban heat island intensity (UHI can be scaled with the urban length scale and the wind speed, through the time-dependent energy balance. The heating of the urban surfaces during the daytime sets the initial temperature, and this overheating is dissipated during the night-time through mean convection motion over the urban surface. This may appear to be in contrast to the classical work by Oke (1973. However, in this work, we show that if the population density is used in converting the population data into urbanized area, then a good agreement with the current theory is found. An additional parameter is the “urban flow parameter,” which depends on the urban building characteristics and affects the horizontal convection of heat due to wind. This scaling can be used to estimate the UHI intensity in any cities and therefore predict the required energy consumption during summer months. In addition, all urbanized surfaces are expected to exhibit this scaling, so that increase in the surface temperature in large energy-consumption or energy-producing facilities (e.g., solar electric or thermal power plants can be estimated.

  10. ‘Oorja’ in India: Assessing a large-scale commercial distribution of advanced biomass stoves to households

    Science.gov (United States)

    Thurber, Mark C.; Phadke, Himani; Nagavarapu, Sriniketh; Shrimali, Gireesh; Zerriffi, Hisham

    2015-01-01

    Replacing traditional stoves with advanced alternatives that burn more cleanly has the potential to ameliorate major health problems associated with indoor air pollution in developing countries. With a few exceptions, large government and charitable programs to distribute advanced stoves have not had the desired impact. Commercially-based distributions that seek cost recovery and even profits might plausibly do better, both because they encourage distributors to supply and promote products that people want and because they are based around properly-incentivized supply chains that could more be scalable, sustainable, and replicable. The sale in India of over 400,000 “Oorja” stoves to households from 2006 onwards represents the largest commercially-based distribution of a gasification-type advanced biomass stove. BP's Emerging Consumer Markets (ECM) division and then successor company First Energy sold this stove and the pelletized biomass fuel on which it operates. We assess the success of this effort and the role its commercial aspect played in outcomes using a survey of 998 households in areas of Maharashtra and Karnataka where the stove was sold as well as detailed interviews with BP and First Energy staff. Statistical models based on this data indicate that Oorja purchase rates were significantly influenced by the intensity of Oorja marketing in a region as well as by pre-existing stove mix among households. The highest rate of adoption came from LPG-using households for which Oorja's pelletized biomass fuel reduced costs. Smoke- and health-related messages from Oorja marketing did not significantly influence the purchase decision, although they did appear to affect household perceptions about smoke. By the time of our survey, only 9% of households that purchased Oorja were still using the stove, the result in large part of difficulties First Energy encountered in developing a viable supply chain around low-cost procurement of “agricultural waste” to

  11. Fluctuation of microbial activities after influent load variations in a full-scale SBR. Recovery of the biomass after starvation

    Energy Technology Data Exchange (ETDEWEB)

    Cabezas, Angela; Draper, Patricia; Etchebehere, Claudia [Universidad de la Republica, Montevideo (Uruguay). Catedra de Microbiologia, Facultad de Quimica y Facultad de Ciencias

    2009-10-15

    Due to variations in the production levels, a full-scale sequencing batch reactor (SBR) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. In order to study how these changes affected the N-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. The recover capacity of the biomass was also studied in a lab-scale reactor operated with intermittent aeration without feeding for 36 days. The results showed that changes in the feeding negatively affected the nitrifying community, but the nitrogen removal efficiencies could be restored after the concentration stress. Species substitution was observed within the nitrifying bacteria, Nitrosomonas europaea and Nitrobacter predominated initially, and after an ammonia overload period, Nitrosomonas nitrosa and Nitrospira became dominant. Some denitrifiers, with nirS related to Alicycliphilus, Azospirillum, and Marinobacter nirS, persisted during long-term reactor operation, but the community fluctuated both in composition and in abundance. This fluctuating community may better resist the continuous changes in the feeding regime. Our results showed that a nitrifying-denitrifying SBR could be operated with low loads or even without feeding during production shut down periods. (orig.)

  12. Heat Transfer Model of a Small-Scale Waste Glass Melter with Cold Cap Layer

    Energy Technology Data Exchange (ETDEWEB)

    Abboud, Alexander; Guillen, Donna Post; Pokorny, Richard

    2016-09-01

    At the Hanford site in the state of Washington, more than 56 million gallons of radioactive waste is stored in underground tanks. The cleanup plan for this waste is vitrification at the Waste Treatment Plant (WTP), currently under construction. At the WTP, the waste will be blended with glass-forming materials and heated to 1423K, then poured into stainless steel canisters to cool and solidify. A fundamental understanding of the glass batch melting process is needed to optimize the process to reduce cost and decrease the life cycle of the cleanup effort. The cold cap layer that floats on the surface of the glass melt is the primary reaction zone for the feed-to-glass conversion. The conversion reactions include water release, melting of salts, evolution of batch gases, dissolution of quartz and the formation of molten glass. Obtaining efficient heat transfer to this region is crucial to achieving high rates of glass conversion. Computational fluid dynamics (CFD) modeling is being used to understand the heat transfer dynamics of the system and provide insight to optimize the process. A CFD model was developed to simulate the DM1200, a pilot-scale melter that has been extensively tested by the Vitreous State Laboratory (VSL). Electrodes are built into the melter to provide Joule heating to the molten glass. To promote heat transfer from the molten glass into the reactive cold cap layer, bubbling of the molten glass is used to stimulate forced convection within the melt pool. A three-phase volume of fluid approach is utilized to model the system, wherein the molten glass and cold cap regions are modeled as separate liquid phases, and the bubbling gas and plenum regions are modeled as one lumped gas phase. The modeling of the entire system with a volume of fluid model allows for the prescription of physical properties on a per-phase basis. The molten glass phase and the gas phase physical properties are obtained from previous experimental work. Finding representative

  13. Handbook for Small-Scale Densified Biomass Fuel (Pellets) Manufacturing for Local Markets.

    Energy Technology Data Exchange (ETDEWEB)

    Folk, Richard L.; Govett, Robert L.

    1992-07-01

    Wood pellet manufacturing in the Intermountain West is a recently founded and rapidly expanding energy industry for small-scale producers. Within a three-year period, the total number of manufacturers in the region has increased from seven to twelve (Folk et al., 1988). Small-scale industry development is evolving because a supply of raw materials from small and some medium-sized primary and secondary wood processors that has been largely unused. For the residue producer considering pellet fuel manufacturing, the wastewood generated from primary products often carries a cost associated with residue disposal when methods at-e stockpiling, landfilling or incinerating. Regional processors use these methods for a variety of reasons, including the relatively small amounts of residue produced, residue form, mixed residue types, high transportation costs and lack of a local market, convenience and absence of regulation. Direct costs associated with residue disposal include the expenses required to own and operate residue handling equipment, costs for operating and maintaining a combustor and tipping fees charged to accept wood waste at public landfills. Economic and social costs related to environmental concerns may also be incurred to include local air and water quality degradation from open-air combustion and leachate movement into streams and drinking water.

  14. Interspecific differences in whole-plant respiration vs. biomass scaling relationships: a case study using evergreen conifer and angiosperm tree seedlings.

    Science.gov (United States)

    Cheng, Dongliang; Niklas, Karl J; Zhong, Quanlin; Yang, Yusheng; Zhang, Jianhua

    2014-04-01

    Empirical studies and theory indicate that respiration rates (R) of small plants scale nearly isometrically with both leaf biomass (ML) and total plant biomass (MT). These predictions are based on angiosperm species and apply only across a small range of body mass. Whether these relationships hold true for different plants, such as conifers, remains unclear. We tested these predictions using the whole-plant maintenance respiration rates and the biomass allocation patterns of the seedlings of two conifer tree species and two angiosperm tree species. Model Type II regression protocols were used to compare the scaling exponents (α) and normalization constants (β) across all four species and within each of the four species. The data show that the scaling exponents varied among the four species and that all differed significantly from isometry. For conifers, scaling exponents for R vs. MT, and R and ML were numerically smaller than those of the broadleaved angiosperm species. However, across the entire data set, R scaled isometrically with ML and with MT as predicted by the West, Brown, and Enquist (WBE) theory. We also observed higher respiration rates for small conifer seedlings compared to comparably sized angiosperm seedlings. Our data add credence to the view that the R vs. M scaling relationship differs among species, and that in general, the numerical values of this interspecific scaling relationship will depend on the species pooled in the analysis and on the range of body sizes within the data set.

  15. UJI PERFORMANSI DESAIN TERINTEGRASI TUNGKU BIOMASSA DAN PENUKAR PANAS (Performance Test of The Integrated Design of Biomass Furnace and Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Muhammad Tahir

    2013-08-01

    Full Text Available A series testing of the integrated design of biomass furnace and heat exchanger was conducted to see the performance using methods such as the effectivenes-number of transfer unit (e-NTU,  the efficiency as a function of Fin Analogy Number (h(Fa and the log-mean temperature difference (LMTD. The biomass furnace as a plant to generated heat produced value of energy 25,600W with the burning rated of corncob 7.03 kg/hour. The calculation of amount of heat transfer to the cold fluid in the tubes as function of fluid characteristic, mass rated of dry air in a longitudinal section was 11,285W. The effectivenes as the ratio of actual heat transfered to the absolute maximum heat that can be transferred in a heat exchanger was 0.90. The efficiency of heat exchanger as a clear measurement of performance system was 0.78. The efficiency as a function of fin analogy number, employed several variable as it function; such as the product of UA, minimum heat capacity rate (Cmin and the capacity ratio (Cr. Another performance showed by correction factor with value of 0.5 indicated that the heat exchanger was not a pure of counter-flow but made of cross-flow in the single segmental baffle with turbulances pattern (Re: 8.524 > 6.000. Keywords: Heat exchanger, biomass furnace, effectivenes, efficiency, performance test   ABSTRAK Serangkaian pengujian terhadap desain terintegrasi tungku biomassa dan penukar panas telah dilakukan untuk melihat performansinya menggunakan metode efektifitas-NTU (e-NTU, efisiensi sebagai fungsi dari fin analogy number (h(Fa dan beda temperatur rata-rata logaritmik (LMTD. Tungku biomassa sebagai pembangkit panas menghasilkan energi senilai 25.600W dengan laju pembakaran tongkol jagung 7.03 kg/jam. Perhitungan laju pindah panas ke fluida dingin dalam pipa sebagai fungsi dari karakteristik udara, laju massa melalui luas penampang laluan diperoleh sebesar 11,285W. Efektivitas sebagai rasio laju pindah panas aktual dengan panas maksimum

  16. Jointly optimizing selection of fuel treatments and siting of forest biomass-based energy production facilities for landscape-scale fire hazard reduction.

    Science.gov (United States)

    Peter J. Daugherty; Jeremy S. Fried

    2007-01-01

    Landscape-scale fuel treatments for forest fire hazard reduction potentially produce large quantities of material suitable for biomass energy production. The analytic framework FIA BioSum addresses this situation by developing detailed data on forest conditions and production under alternative fuel treatment prescriptions, and computes haul costs to alternative sites...

  17. BIOMASS-FUELED, SMALL-SCALE, INTEGRATED-GASIFIER, GAS-TURBINE POWER PLANT: PROGRESS REPORT ON THE PHASE 2 DEVELOPMENT

    Science.gov (United States)

    The paper reports the latest efforts to complete development of Phase 2 of a three-phase effort to develop a family of small-scale (1 to 20 MWe) biomass-fueled power plants. The concept envisioned is an air-blown pressurized fluidized-bed gasifier followed by a dry hot gas clean...

  18. Biomass potential

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, D. [VTT Energy, Espoo (Finland)

    1996-12-31

    Biomass resources of the industrialised countries are enormous, if only a small fraction of set-aside fields were used for energy crops. Forest resources could also be utilised more efficiently than at present for large-scale energy production. The energy content of the annual net growth of the total wood biomass is estimated to be 180 million toe in Europe without the former USSR, and about 50 million toe of that in the EC area, in 1990. Presently, the harvesting methods of forest biomass for energy production are not yet generally competitive. Among the most promising methods are integrated harvesting methods, which supply both raw material to the industry and wood fuel for energy production. Several new methods for separate harvesting of energy wood are being developed in many countries. (orig.)

  19. Multi-scale structure, pasting and digestibility of heat moisture treated red adzuki bean starch.

    Science.gov (United States)

    Wang, Hongwei; Wang, Zhaoyuan; Li, Xiaoxi; Chen, Ling; Zhang, Binjia

    2017-09-01

    The pasting and digestibility of a red adzuki bean starch were simultaneously modulated by heat-moisture treatment (HMT) through altering the multi-scale structure. HMT, especially at high moisture content, could disrupt the granule integrity, semicrystalline lamellae, molecular order (crystallites) and molecular chains. Also, certain rearrangement of starch molecules occurred to form ordered structures with increased thermal stability as shown by DSC. This concomitant disordering and reassembly in the multi-scale structure converted the fractions of resistant starch (RS) and rapidly digestible starch (RDS) into that of slowly digestible starch (SDS). Furthermore, the emergence of thermally-stable orders increased the pasting temperature but suppressed the swelling of granules during heating. Hence, HMT-modified red adzuki starch may serve as a potential thickener/gelling agent with slow digestion rate for various foods. Copyright © 2017. Published by Elsevier B.V.

  20. Multi-scale Control and Enhancement of Reactor Boiling Heat Flux by Reagents and Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Manglik, R M; Athavale, A; Kalaikadal, D S; Deodhar, A; Verma, U

    2011-09-02

    The phenomenological characterization of the use of non-invasive and passive techniques to enhance the boiling heat transfer in water has been carried out in this extended study. It provides fundamental enhanced heat transfer data for nucleate boiling and discusses the associated physics with the aim of addressing future and next-generation reactor thermal-hydraulic management. It essentially addresses the hypothesis that in phase-change processes during boiling, the primary mechanisms can be related to the liquid-vapor interfacial tension and surface wetting at the solidliquid interface. These interfacial characteristics can be significantly altered and decoupled by introducing small quantities of additives in water, such as surface-active polymers, surfactants, and nanoparticles. The changes are fundamentally caused at a molecular-scale by the relative bulk molecular dynamics and adsorption-desorption of the additive at the liquid-vapor interface, and its physisorption and electrokinetics at the liquid-solid interface. At the micro-scale, the transient transport mechanisms at the solid-liquid-vapor interface during nucleation and bubblegrowth can be attributed to thin-film spreading, surface-micro-cavity activation, and micro-layer evaporation. Furthermore at the macro-scale, the heat transport is in turn governed by the bubble growth and distribution, macro-layer heat transfer, bubble dynamics (bubble coalescence, collapse, break-up, and translation), and liquid rheology. Some of these behaviors and processes are measured and characterized in this study, the outcomes of which advance the concomitant fundamental physics, as well as provide insights for developing control strategies for the molecular-scale manipulation of interfacial tension and surface wetting in boiling by means of polymeric reagents, surfactants, and other soluble surface-active additives.

  1. Large-scale calculations of gas phase thermochemistry : Enthalpy of formation, standard entropy, and heat capacity

    OpenAIRE

    Ghahremanpour, Mohammad M.; van Maaren, Paul J.; Ditz, Jonas C.; Lindh, Roland; van der Spoel, David

    2016-01-01

    Large scale quantum calculations for molar enthalpy of formation (Delta(f) H-0), standard entropy (S-0), and heat capacity (C-V) are presented. A large data set may help to evaluate quantum thermochemistry tools in order to uncover possible hidden shortcomings and also to find experimental data that might need to be reinvestigated, indeed we list and annotate approximately 200 problematic thermochemistry measurements. Quantum methods systematically underestimate S-0 for flexible molecules in ...

  2. Feasibility Assessment of Using Power Plant Waste Heat in Large Scale Horticulture Facility Energy Supply Systems

    OpenAIRE

    Min Gyung Yu; Yujin Nam

    2016-01-01

    Recently, the Korean government has been carrying out projects to construct several large scale horticulture facilities. However, it is difficult for an energy supply to operate stably and economically with only a conventional fossil fuel boiler system. For this reason, several unused energy sources have become attractive and it was found that power plant waste heat has the greatest potential for application in this scenario. In this study, we performed a feasibility assessment of power plant...

  3. Reduction in biomass burning aerosol light absorption upon humidification: Roles of inorganically-induced hygroscopicity, particle collapse, and photoacoustic heat and mass transfer

    Energy Technology Data Exchange (ETDEWEB)

    lewis, Kristen A.; Arnott, W. P.; Moosmuller, H.; Chakrabarti, Raj; Carrico, Christian M.; Kreidenweis, Sonia M.; Day, Derek E.; Malm, William C.; Laskin, Alexander; Jimenez, Jose L.; Ulbrich, Ingrid M.; Huffman, John A.; Onasch, Timothy B.; Trimborn, Achim; Liu, Li; Mishchenko, M.

    2009-11-27

    Smoke particle emissions from the combustion of biomass fuels typical for the western and southeastern United States were studied and compared under high humidity and ambient conditions in the laboratory. The fuels used are Montana ponderosa pine (Pinus ponderosa), southern California chamise (Adenostoma fasciculatum), and Florida saw palmetto (Serenoa repens). Information on the non-refractory chemical composition of biomass burning aerosol from each fuel was obtained with an aerosol mass spectrometer and through estimation of the black carbon concentration from light absorption measurements at 870 nm. Changes in the optical and physical particle properties under high humidity conditions were observed for hygroscopic smoke particles containing substantial inorganic mass fractions that were emitted from combustion of chamise and palmetto fuels. Light scattering cross sections increased under high humidity for these particles, consistent with the hygroscopic growth measured for 100 nm particles in HTDMA measurements. Photoacoustic measurements of aerosol light absorption coefficients reveal a 20% reduction with increasing relative humidity, contrary to the expectation of light absorption enhancement by the liquid coating taken up by hygroscopic particles. This reduction is hypothesized to arise from two mechanisms: 1. Shielding of inner monomers after particle consolidation or collapse with water uptake; 2. The contribution of mass transfer through evaporation and condensation at high relative humidity to the usual heat transfer pathway for energy release by laser heated particles in the photoacoustic measurement of aerosol light absorption. The mass transfer contribution is used to evaluate the fraction of aerosol surface covered with liquid water solution as a function of RH.

  4. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Bruce C. Folkedahl; Jay R. Gunderson; Darren D. Schmidt; Greg F. Weber; Christopher J. Zygarlicke

    2002-09-01

    The Energy & Environmental Research Center (EERC) has completed a project to examine fundamental issues that could limit the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC attempted to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low-volatile fuels with lower reactivities can experience problematic fouling when switched to higher-volatile and more reactive coal-biomass blends. Higher heat release rates at the grate can cause increased clinkering or slagging at the grate due to higher temperatures. Combustion and loss of volatile matter can start much earlier for biomass fuels compared to design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the stoker, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates, various chlorides, and phosphates. These species in combination with different flue gas temperatures, because of changes in fuel heating value, can adversely affect ash deposition behavior. The goal of this project was to identify the primary ash mechanisms related to grate clinkering and heat exchange surface fouling associated with cofiring coal and biomass--specifically wood and agricultural residuals--in grate-fired systems, leading to future mitigation of these problems. The specific technical objectives of the project were: (1) Modification of an existing pilot-scale combustion system to simulate a grate-fired system. (2) Verification testing of the simulator. (3) Laboratory-scale testing and fuel characterization to

  5. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Bruce C. Folkedahl; Darren D. Schmidt; Greg F. Weber; Christopher J. Zygarlicke

    2001-10-01

    The Energy & Environmental Research Center (EERC) is conducting a project to examine the fundamental issues limiting the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC is attempting to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low volatile fuels with lower reactivities can experience damaging fouling when switched to higher volatile and more reactive lower-rank fuels, such as when cofiring biomass. Higher heat release rates at the grate can cause more clinkering or slagging at the grate because of higher temperatures. Combustion and loss of volatile matter can start too early for biomass fuels compared to the design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the stoker, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates and various chlorides, in combination with different flue gas temperatures because of changes in fuel heating value which can adversely affect ash deposition behavior. The goal of this project is to identify the primary ash mechanisms related to grate clinkering and heat exchange surface fouling associated with cofiring coal and biomass--specifically wood and agricultural residuals--in grate-fired systems, leading to future mitigation of these problems. The specific technical objectives of the project are: Modification of an existing EERC pilot-scale combustion system to simulate a grate-fired system; Verification testing of the simulator; Laboratory-scale testing and fuel characterization to determine ash

  6. Large spatial scale variability in bathyal macrobenthos abundance, biomass, α- and β-diversity along the Mediterranean continental margin.

    Directory of Open Access Journals (Sweden)

    Elisa Baldrighi

    Full Text Available The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can be seen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project ("Biodiversity and Ecosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna", we investigated the large spatial scale variability (over >1,000 km of the bathyal macrofauna communities that inhabit the Mediterranean basin, and their relationships with the environmental variables. The macrofauna abundance, biomass, community structure and functional diversity were analysed and the α-diversity and β-diversity were estimated across six selected slope areas at different longitudes and along three main depths. The macrobenthic standing stock and α-diversity were lower in the deep-sea sediments of the eastern Mediterranean basin, compared to the western and central basins. The macrofaunal standing stock and diversity decreased significantly from the upper bathyal to the lower bathyal slope stations. The major changes in the community composition of the higher taxa and in the trophic (functional structure occurred at different longitudes, rather than at increasing water depth. For the β-diversity, very high dissimilarities emerged at all levels: (i between basins; (ii between slopes within the same basin; and (iii between stations at different depths; this therefore demonstrates the high macrofaunal diversity of the Mediterranean basins at large spatial scales. Overall, the food sources (i.e., quantity and quality that characterised the west, central and eastern Mediterranean basins, as well as sediment grain size, appear to influence the macrobenthic standing stock and the biodiversity along the different slope areas.

  7. Large spatial scale variability in bathyal macrobenthos abundance, biomass, α- and β-diversity along the Mediterranean continental margin.

    Science.gov (United States)

    Baldrighi, Elisa; Lavaleye, Marc; Aliani, Stefano; Conversi, Alessandra; Manini, Elena

    2014-01-01

    The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can be seen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project ("Biodiversity and Ecosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna"), we investigated the large spatial scale variability (over >1,000 km) of the bathyal macrofauna communities that inhabit the Mediterranean basin, and their relationships with the environmental variables. The macrofauna abundance, biomass, community structure and functional diversity were analysed and the α-diversity and β-diversity were estimated across six selected slope areas at different longitudes and along three main depths. The macrobenthic standing stock and α-diversity were lower in the deep-sea sediments of the eastern Mediterranean basin, compared to the western and central basins. The macrofaunal standing stock and diversity decreased significantly from the upper bathyal to the lower bathyal slope stations. The major changes in the community composition of the higher taxa and in the trophic (functional) structure occurred at different longitudes, rather than at increasing water depth. For the β-diversity, very high dissimilarities emerged at all levels: (i) between basins; (ii) between slopes within the same basin; and (iii) between stations at different depths; this therefore demonstrates the high macrofaunal diversity of the Mediterranean basins at large spatial scales. Overall, the food sources (i.e., quantity and quality) that characterised the west, central and eastern Mediterranean basins, as well as sediment grain size, appear to influence the macrobenthic standing stock and the biodiversity along the different slope areas.

  8. Thermal chip fabrication with arrays of sensors and heaters for micro-scale impingement cooling heat transfer analysis and measurements.

    Science.gov (United States)

    Shen, C H; Gau, C

    2004-07-30

    The design and fabrication for a thermal chip with an array of temperature sensors and heaters for study of micro-jet impingement cooling heat transfer process are presented. This thermal chip can minimize the heat loss from the system to the ambient and provide a uniform heat flux along the wall, thus local heat transfer processes along the wall can be measured and obtained. The fabrication procedure presented can reach a chip yield of 100%, and every one of the sensors and heaters on the chip is in good condition. In addition, micro-jet impingement cooling experiments are performed to obtain the micro-scale local heat transfer Nusselt number along the wall. Flow visualization for the micro-impinging jet is also made. The experimental results indicate that both the micro-scale impinging jet flow structure and the heat transfer process along the wall is significantly different from the case of large-scale jet impingement cooling process.

  9. Scale Resistant Heat Exchanger for Low Temperature Geothermal Binary Cycle Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hays, Lance G. [Energent Corporation, Santa Ana, CA (United States)

    2014-11-18

    Phase 1 of the investigation of improvements to low temperature geothermal power systems was completed. The improvements considered were reduction of scaling in heat exchangers and a hermetic turbine generator (eliminating seals, seal system, gearbox, and lube oil system). A scaling test system with several experiments was designed and operated at Coso geothermal resource with brine having a high scaling potential. Several methods were investigated at the brine temperature of 235 ºF. One method, circulation of abradable balls through the brine passages, was found to substantially reduce scale deposits. The test heat exchanger was operated with brine outlet temperatures as low as 125 ºF, which enables increased heat input available to power conversion systems. For advanced low temperature cycles, such as the Variable Phase Cycle (VPC) or Kalina Cycle, the lower brine temperature will result in a 20-30% increase in power production from low temperature resources. A preliminary design of an abradable ball system (ABS) was done for the heat exchanger of the 1 megawatt VPC system at Coso resource. The ABS will be installed and demonstrated in Phase 2 of this project, increasing the power production above that possible with the present 175 ºF brine outlet limit. A hermetic turbine generator (TGH) was designed and manufacturing drawings produced. This unit will use the working fluid (R134a) to lubricate the bearings and cool the generator. The 200 kW turbine directly drives the generator, eliminating a gearbox and lube oil system. Elimination of external seals eliminates the potential of leakage of the refrigerant or hydrocarbon working fluids, resulting in environmental improvement. A similar design has been demonstrated by Energent in an ORC waste heat recovery system. The existing VPC power plant at Coso was modified to enable the “piggyback” demonstration of the TGH. The existing heat exchanger, pumps, and condenser will be operated to provide the required

  10. Occupational exposure in small and medium scale industry with specific reference to heat and noise.

    Science.gov (United States)

    Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, Kishore Kumar

    2010-01-01

    This study was undertaken to assess heat and noise exposure and occupational safety practices in small and medium scale casting and forging units (SMEs) of Northern India. We conducted personal interviews of 350 male workers of these units through a comprehensive questionnaire and collected information on heat and noise exposure, use of protective equipment, sweat loss and water intake, working hour. The ambient wet bulb globe temperature (WBGT index) was measured using quest temp 34/36o area heat stress monitor. A-weighted Leq ambient noise was measured using a quest sound level meter "ANSI SI. 43-1997 (R 2002) type-1 model SOUNDPRO SE/DL". We also incorporated OSHA norms for hearing conservation which include - an exchange rate of 5dB(A), criterion level at 90dB(A), criterion time of eight hours, threshold level is equal to 80dB(A), upper limit is equal to 140dB(A) and with F/S response rate. Results of the study revealed that occupational heat exposure in melting, casting, forging and punching sections is high compared to ACGIH/NIOSH norms. Ambience noise in various sections like casting / molding, drop forging, cutting presses, punching, grinding and barreling process was found to be more than 90dB(A). About 95% of the workers suffered speech interference where as high noise annoyance was reported by only 20%. Overall, 68% workers were not using any personal protective equipment (PPE). The study concluded that the proportion of SME workers exposed to high level heat stress and noise (60 - 72 hrs/week) is high. The workers engaged in forging and grinding sections are more prone to noise induced hearing loss (NIHL) at higher frequencies as compared to workers of other sections. It is recommended that there is a strong need to implement the standard of working hours as well as heat stress and noise control measures.

  11. Occupational exposure in small and medium scale industry with specific reference to heat and noise

    Directory of Open Access Journals (Sweden)

    Lakhwinder Pal Singh

    2010-01-01

    Full Text Available This study was undertaken to assess heat and noise exposure and occupational safety practices in small and medium scale casting and forging units (SMEs of Northern India. We conducted personal interviews of 350 male workers of these units through a comprehensive questionnaire and collected information on heat and noise exposure, use of protective equipment, sweat loss and water intake, working hour. The ambient wet bulb globe temperature (WBGT index was measured using quest temp 34/36o area heat stress monitor. A-weighted Leq ambient noise was measured using a quest sound level meter "ANSI SI. 43-1997 (R 2002 type-1 model SOUNDPRO SE/DL". We also incorporated OSHA norms for hearing conservation which include - an exchange rate of 5dB(A, criterion level at 90dB(A, criterion time of eight hours, threshold level is equal to 80dB(A, upper limit is equal to 140dB(A and with F/S response rate. Results of the study revealed that occupational heat exposure in melting, casting, forging and punching sections is high compared to ACGIH/NIOSH norms. Ambience noise in various sections like casting / molding, drop forging, cutting presses, punching, grinding and barreling process was found to be more than 90dB(A. About 95% of the workers suffered speech interference where as high noise annoyance was reported by only 20%. Overall, 68% workers were not using any personal protective equipment (PPE. The study concluded that the proportion of SME workers exposed to high level heat stress and noise (60 - 72 hrs/week is high. The workers engaged in forging and grinding sections are more prone to noise induced hearing loss (NIHL at higher frequencies as compared to workers of other sections. It is recommended that there is a strong need to implement the standard of working hours as well as heat stress and noise control measures.

  12. Small-scale dynamo magnetism as the driver for heating the solar atmosphere.

    Science.gov (United States)

    Amari, Tahar; Luciani, Jean-François; Aly, Jean-Jacques

    2015-06-11

    The long-standing problem of how the solar atmosphere is heated has been addressed by many theoretical studies, which have stressed the relevance of two specific mechanisms, involving magnetic reconnection and waves, as well as the necessity of treating the chromosphere and corona together. But a fully consistent model has not yet been constructed and debate continues, in particular about the possibility of coronal plasma being heated by energetic phenomena observed in the chromosphere. Here we report modelling of the heating of the quiet Sun, in which magnetic fields are generated by a subphotospheric fluid dynamo intrinsically connected to granulation. We find that the fields expand into the chromosphere, where plasma is heated at the rate required to match observations (4,500 watts per square metre) by small-scale eruptions that release magnetic energy and drive sonic motions. Some energetic eruptions can even reach heights of 10 million metres above the surface of the Sun, thereby affecting the very low corona. Extending the model by also taking into account the vertical weak network magnetic field allows for the existence of a mechanism able to heat the corona above, while leaving unchanged the physics of chromospheric eruptions. Such a mechanism rests on the eventual dissipation of Alfvén waves generated inside the chromosphere and that carry upwards the required energy flux of 300 watts per square metre. The model shows a topologically complex magnetic field of 160 gauss on the Sun's surface, agreeing with inferences obtained from spectropolarimetric observations, chromospheric features (contributing only weakly to the coronal heating) that can be identified with observed spicules and blinkers, and vortices that may be possibly associated with observed solar tornadoes.

  13. Power generation in small scale from gasification of biomass; Geracao eletrica em pequena escala a partir da gaseificacao de biomassa

    Energy Technology Data Exchange (ETDEWEB)

    Lora, Electo Eduardo Silva; Andrade, Rubenildo Vieira; Aradas, Maria Eugenia Corria [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Engenharia Mecanica. Nucleo de Excelencia em Geracao Termeletrica e Distribuida (NEST)

    2004-07-01

    This paper present a review about biomass gasifier technology and discuss its advantages, disadvantages and applications as well as shows some succeeded experiences in this area. The paper also presents an analysis of the biomass gas use in alternative engines and in new distributed generation technology such as Stirling engines and microturbines. (author)

  14. Ionospheric plasma disturbances generated by naturally occurring large-scale anomalous heat sources

    Science.gov (United States)

    Pradipta, Rezy; Lee, Min-Chang; Coster, Anthea J.; Tepley, Craig A.; Sulzer, Michael P.; Gonzalez, Sixto A.

    2017-04-01

    We report the findings from our investigation on the possibility of large-scale anomalous thermal gradients to generate acoustic-gravity waves (AGWs) and traveling ionospheric disturbances (TIDs). In particular, here we consider the case of summer 2006 North American heat wave event as a concrete example of such large-scale natural thermal gradients. This special scenario of AGW/TID generation was formulated based on the results of our experiments at the Arecibo Observatory in July 2006, followed by a systematic monitoring/surveillance of total electron content (TEC) fluctuations over North America in 2005-2007 using the MIT Haystack Observatory's Madrigal database. The data from our Arecibo experiments indicate a continual occurrence of intense AGW/TID over the Caribbean on 21-24 July 2006, and the Madrigal TEC data analysis shows that the overall level of TID activity over North America had increased by ∼0.2 TECU during the summer 2006 heat wave event. Our proposed scenario is in agreement with these empirical observations, and is generally consistent with a number of past ionospheric HF heating experiments related to AGW/TID generation.

  15. Aspect ratio dependence of heat transfer and large-scale flow in turbulent convection

    CERN Document Server

    Bailon-Cuba, Jorge; Schumacher, Joerg

    2010-01-01

    The heat transport and corresponding changes in the large-scale circulation (LSC) in turbulent Rayleigh-B\\'{e}nard convection are studied by means of three-dimensional direct numerical simulations as a function of the aspect ratio $\\Gamma$ of a closed cylindrical cell and the Rayleigh number $Ra$. For small and moderate aspect ratios, the global heat transfer law $Nu=A\\times Ra^{\\beta}$ shows a power law dependence of both fit coefficients $A$ and $\\beta$ on the aspect ratio. A minimum Nusselt number coincides with the point where the LSC undergoes a transition from a single-roll to a double-roll pattern. With increasing aspect ratio, we detect complex multi-roll LSC configurations. The aspect ratio dependence of the turbulent heat transfer for small and moderate $\\Gamma$ is in line with a varying amount of energy contained in the LSC, as quantified by the Proper Orthogonal Decomposition analysis. For $\\Gamma\\gtrsim 8$ the heat transfer becomes independent of the aspect ratio.

  16. Multi-scaling Properties of EUV Intensity Fluctuations and Models for Impulsive Heating

    Science.gov (United States)

    Cadavid, A. C.; Rivera, Y.; Lawrence, J. K.; Christian, D. J.; Jennings, P.; Rappazzo, A. F.

    2016-12-01

    There is wide agreement on the importance of impulsive processes ("nanoflares") to explain coronal heating. Diagnostics of observational data are necessary to uncover signatures of the underlying mechanisms, and, by comparing to those of simulated data, to determine whether a model explains the observations. We have investigated the multi-scaling properties that characterize the intermittency of AIA/SDO radiance fluctuations. Lags between pairs of wavebands were used to distinguish coronal from transition region (TR) signals. Noise degrades the signals, so the 171Å emission, with the highest signal-to-noise ratio, provides the best information. In an active region core, for both loops and for diffuse emission, the probability distribution functions (PDFs) of the increments of both TR and coronal signals are "quasi-Gaussian" for large temporal scales and "leptokurtic" (peaked with heavy tails) for small time increments, as expected for turbulent systems. Multifractal Detrended Fluctuation Analysis (MF-DFA) shows that the variance of the fluctuations obeys a power law as a function of temporal scales in the range 15-45 min. The value of the scaling exponent indicates that, on average, the time series are nonstationary and anti-persistent with small fluctuations following large fluctuations and vice versa. Other moments of the fluctuations obey corresponding power laws and the multi-scaling exponents quantify the degree of the intermittency in the context of multifractality. The variation in the scaling exponents results from long term correlation in the time series. The multiscaling of the EUV data agrees qualitatively with simulated intensity from a simple model of impulsive bursts plus noise, and also with the ohmic dissipation in a Reduced Magnetohydrodynamic (RMHD) model for coronal loop heating. However, the observational data were found to disagree with the modeled PDFs of increments. There is indication that the multifractal properties in the observations

  17. The use of biomass for energy in Sweden. Critical factors and lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Bengt; Boerjesson, Paal; Ericsson, Karin; Nilsson, Lars J.; Svenningsson, Per

    2002-08-01

    In this report the development of Swedish biomass use during recent decades is discussed. The relations between biomass supply, biomass demand and various policy initiatives are explored. The objectives are to discuss the most important factors affecting the biomass development and to establish which factors are specific for Swedish conditions and also to identify general factors that are relevant in assessing the possibility of expanding biomass use in different contexts. The focus is on the use of biomass for heat and electricity production. Biomass contributed 14% to the Swedish energy supply in 1999. The major fraction of Swedish biomass is used within the forest industry (63%) and in district heating systems (23%). The remaining fraction is used in small-scale boilers in one- and two family dwellings. Between 1990 and 1999 Swedish bioenergy use (including waste and peat) increased by 44%. During the same period there has been a fourfold increase in the district heating systems. By-products from forestry and the Swedish forest industry dominate the supply of biomass in Sweden, but the importation of biomass increased significantly during the 1990s. A number of factors of various kinds have interacted to bring about the increased use of biomass in Sweden during the past twenty years. These factors can be divided into three categories: structure, policies and actors. The existence of a major forest industry and well-developed district heating systems has enabled a rapid response to strong and standing policy commitments to biomass. The reformation of the taxation system, with the introduction of a high carbon tax on fossil fuels, has led to significantly improved competitiveness for biomass when used for heating purposes.

  18. Efficient protocols for Stirling heat engines at the micro-scale

    Science.gov (United States)

    Muratore-Ginanneschi, Paolo; Schwieger, Kay

    2015-10-01

    We investigate the thermodynamic efficiency of sub-micro-scale Stirling heat engines operating under the conditions described by overdamped stochastic thermodynamics. We show how to construct optimal protocols such that at maximum power the efficiency attains for constant isotropic mobility the universal law η=2 ηC/(4-ηC) , where ηC is the efficiency of an ideal Carnot cycle. We show that these protocols are specified by the solution of an optimal mass transport problem. Such solution can be determined explicitly using well-known Monge-Ampère-Kantorovich reconstruction algorithms. Furthermore, we show that the same law describes the efficiency of heat engines operating at maximum work over short time periods. Finally, we illustrate the straightforward extension of these results to cases when the mobility is anisotropic and temperature dependent.

  19. Scaled model studies of decay heat removal by natural convection for sodium cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, H. (Institut fuer Angewandte Thermo- und Fluiddynamik (IATF), Kernforschungszentrum Karlsruhe (Germany)); Weinberg, D. (Institut fuer Angewandte Thermo- und Fluiddynamik (IATF), Kernforschungszentrum Karlsruhe (Germany)); Marten, K. (Institut fuer Angewandte Thermo- und Fluiddynamik (IATF), Kernforschungszentrum Karlsruhe (Germany)); Schnetgoeke, G. (Institut fuer Angewandte Thermo- und Fluiddynamik (IATF), Kernforschungszentrum Karlsruhe (Germany))

    1993-06-01

    Thermohydraulic experiments were performed with water in order to simulate decay heat removal by natural convection in a pool-type sodium cooled reactor. Two water test rigs of different scales were used, namely, RAMONA (1:20) and NEPTUN (1:5). RAMONA was taken to study the transition from nominal operation by forced convection to decay heat removal operation by natural convection. Steady-state similarity tests were carried out in both facilities. All tests provide a basis for verification of computer programs. Calculations performed with the three-dimensional code FLUTAN proved that the thermohydraulic processes are quantitatively mastered, even for the very complex geometry of the NEPTUN test rig. (orig.)

  20. TRMM Latent Heating Retrieval and Comparisons with Field Campaigns and Large-Scale Analyses

    Science.gov (United States)

    Tao, Wei-Kuo; Takayabu, Yukuri; Lang, S.; Shige, S.; Olson, W.; Hou, A.; Jiang, X.; Zhang, C.; Lau, W.; Krishnamurti, T.; hide

    2012-01-01

    Rainfall production is a fundamental process within the Earth's hydrological cycle because it represents both a principal forcing term in surface water budgets, and its energetics corollary, latent heating (LH), is one of the principal sources of atmospheric diabatic heating. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water. The vertical distribution of LH has a strong influence on the atmosphere, controlling large-scale tropical circulations, exciting and modulating tropical waves, maintaining the intensities of tropical cyclones, and even providing the energetics of midlatitude cyclones and other mobile midlatitude weather systems. Moreover, the processes associated with LH result in significant non-linear changes in atmospheric radiation through the creation, dissipation and modulation of clouds and precipitation. Yanai et al. (1973) utilized the meteorological data collected from a sounding network to present a pioneering work on thermodynamic budgets, which are referred to as the apparent heat source (Q1) and apparent moisture sink (Q2). Yanai's paper motivated the development of satellite-based LH algorithms and provided a theoretical background for imposing large-scale advective forcing into cloud-resolving models (CRMs). These CRM-simulated LH and Q1 data have been used to generate the look-up tables used in LH algorithms. This paper examines the retrieval, validation, and application of LH estimates based on rain rate quantities acquired from the Tropical Rainfall Measuring Mission satellite (TRMM). TRMM was launched in November 1997 as a joint enterprise between the American and Japanese space agencies -- with overriding goals of providing accurate four-dimensional estimates of rainfall and LH over the global Tropics and subtropics equatorward of 35o. Other literature has acknowledged the achievement of the first goal of obtaining an accurate rainfall climatology. This paper describes the

  1. Fully determined scaling laws for volumetrically heated convective systems, a tool for assessing habitability of exoplanets

    Science.gov (United States)

    Vilella, Kenny; Kaminski, Edouard

    2017-05-01

    The long-term habitability of a planet rises from its ability to generate and maintain an atmosphere through partial melting and volcanism. This question has been mainly addressed in the framework of plate tectonics, which may be too specific to apply to the wide range of internal dynamics expected for exoplanets, and even to the thermal evolution of the early Earth. Here we propose a more general theoretical approach of convection to build a regime diagram giving the conditions for partial melting to occur, in planetary bodies, as a function of key parameters that can be estimated for exoplanets, their size and internal heating rate. To that aim, we introduce a refined view of the Thermal Boundary Layer (TBL) in a convective system heated from within, that focuses on the temperature and thickness of the TBL at the top of the hottest temperature profiles, along which partial melting shall first occur. This ;Hottest Thermal Boundary Layer; (HotTBL) is first characterized using fully theoretical scaling laws based on the dynamics of thermal boundary layers. These laws are the first ones proposed in the literature that do not rely on empirical determinations of dimensionless constants and that apply to both low Rayleigh and high Rayleigh convective regimes. We show that the scaling laws can be successfully applied to planetary bodies by comparing their predictions to full numerical simulations of the Moon. We then use the scaling laws to build a regime diagram for exoplanets. Combined with estimates of internal heating in exoplanets, the regime diagram predicts that in the habitable zone partial melting occurs in planets younger than the Earth.

  2. Geothermal Heat Flux: Linking Deep Earth's Interior and the Dynamics of Large-Scale Ice Sheets

    Science.gov (United States)

    Rogozhina, Irina; Vaughan, Alan

    2014-05-01

    Regions covered by continental-scale ice sheets have the highest degree of uncertainty in composition and structure of the crust and lithospheric mantle, compounded by the poorest coverage on Earth of direct heat flow measurements. In addition to challenging conditions that make direct measurements and geological survey difficult Greenland and Antarctica are known to be geologically complex. Antarctica in particular is marked by two lithospherically distinct zones. In contrast to young and thin lithosphere of West Antarctica, East Antarctica is a collage of thick Precambrian fragments of Gondwana and earlier supercontinents. However, recent observations and modeling studies have detected large systems of subglacial lakes extending beneath much of the East Antarctic ice sheet base that have been linked to anomalously elevated heat flow. Outcrop samples from the rift margin with Australia (Prydz Bay) have revealed highly radiogenic Cambrian granite intrusives that are implicated in regional increase of crustal heat flux by a factor of two to three compared to the estimated continental background. Taken together, these indicate high variability of heat flow and properties of rocks across Antarctica. Similar conclusions have been made based on direct measurements and observations of the Greenland ice sheet. Airborne ice-penetrating radar and deep ice core projects show very high rates of basal melt for parts of the ice sheet in northern and central Greenland that have been explained by abnormally high heat flux. Archaean in age, the Greenland lithosphere was significantly reworked during the Early Proterozoic. In this region, the interpretation of independent geophysical data is complicated by Proterozoic and Phanerozoic collision zones, compounded by strong thermochemical effects of rifting along the western and eastern continental margins between 80 and 25 million years ago. In addition, high variability of heat flow and thermal lithosphere structure in central

  3. Potential Increasing of Rubber Sheet Production with Fungus Displacement by Solar Tunnel Dryer by Integrating a Biomass Gasifier as an Assisting Heat Source

    Science.gov (United States)

    Dangphonthong, D.; Ruenruangrit, P.; Pinate, W.

    2017-10-01

    In this study, Potential increasing of rubber sheet production with fungus displacement by solar tunnel dryer. By integrating a biomass gasifier as an assisting heat source for drying Rubber Sheet produce and its performance analysis has been investigated. An experimental study has been carried out with the stand-alone solar tunnel dryer and the dryer with the assisted biomass gasifier. For thermal performance analysis, for wind speed 1.0 m/s, the dryer with assisted gasifier gave an average efficiency of 32.86% higher and the drying period was 31.45 % shorter than those of the unit without the gasifier. For wind speed 1.5 m/s, and for wind speed 2.0 m/s, the values are 21.49 %, 28.68 % and 33.17%, 24.54 %, respectively. From the economic analysis, drying of wind speed 1.5 m/s is the most appropriated. The payback and the IRR were 1.8 years and 55.48 %, respectively. While those for wind speed 1.0 m/s were 2.74 years and 36%, respectively.

  4. Co-firing Bosnian coals with woody biomass: Experimental studies on a laboratory-scale furnace and 110 MWe power unit

    Directory of Open Access Journals (Sweden)

    Smajevic Izet

    2012-01-01

    Full Text Available This paper presents the findings of research into cofiring two Bosnian cola types, brown coal and lignite, with woody biomass, in this case spruce sawdust. The aim of the research was to find the optimal blend of coal and sawdust that may be substituted for 100% coal in large coal-fired power stations in Bosnia and Herzegovina. Two groups of experimental tests were performed in this study: laboratory testing of co-firing and trial runs on a large-scale plant based on the laboratory research results. A laboratory experiment was carried out in an electrically heated and entrained pulverized-fuel flow furnace. Coal-sawdust blends of 93:7% by weight and 80:20% by weight were tested. Co-firing trials were conducted over a range of the following process variables: process temperature, excess air ratio and air distribution. Neither of the two coal-sawdust blends used produced any significant ash-related problems provided the blend volume was 7% by weight sawdust and the process temperature did not exceed 1250ºC. It was observed that in addition to the nitrogen content in the co-fired blend, the volatile content and particle size distribution of the mixture also influenced the level of NOx emissions. The brown coal-sawdust blend generated a further reduction of SO2 due to the higher sulphur capture rate than for coal alone. Based on and following the laboratory research findings, a trial run was carried out in a large-scale utility - the Kakanj power station, Unit 5 (110 MWe, using two mixtures; one in which 5%/wt and one in which 7%/wt of brown coal was replaced with sawdust. Compared to a reference firing process with 100% coal, these co-firing trials produced a more intensive redistribution of the alkaline components in the slag in the melting chamber, with a consequential beneficial effect on the deposition of ash on the superheater surfaces of the boiler. The outcome of the tests confirms the feasibility of using 7%wt of sawdust in combination

  5. Reduction in biomass burning aerosol light absorption upon humidification: roles of inorganically-induced hygroscopicity, particle collapse, and photoacoustic heat and mass transfer

    Directory of Open Access Journals (Sweden)

    L. Liu

    2009-11-01

    Full Text Available Smoke particle emissions from the combustion of biomass fuels typical for the western and southeastern United States were studied and compared under high humidity and ambient conditions in the laboratory. The fuels used were Montana ponderosa pine (Pinus ponderosa, southern California chamise (Adenostoma fasciculatum, and Florida saw palmetto (Serenoa repens. Information on the non-refractory chemical composition of biomass burning aerosol from each fuel was obtained with an aerosol mass spectrometer and through estimation of the black carbon concentration from light absorption measurements at 870 nm. Changes in the optical and physical particle properties under high humidity conditions were observed for hygroscopic smoke particles containing substantial inorganic mass fractions that were emitted from combustion of chamise and palmetto fuels. Light scattering cross sections increased under high humidity for these particles, consistent with the hygroscopic growth measured for 100 nm particles in HTDMA measurements. Photoacoustic measurements of aerosol light absorption coefficients revealed a 20% reduction with increasing relative humidity, contrary to the expectation of light absorption enhancement by the liquid coating taken up by hygroscopic particles. This reduction is hypothesized to arise from two mechanisms: (1 shielding of inner monomers after particle consolidation or collapse with water uptake; (2 the lower case contribution of mass transfer through evaporation and condensation at high relative humidity (RH to the usual heat transfer pathway for energy release by laser-heated particles in the photoacoustic measurement of aerosol light absorption. The mass transfer contribution is used to evaluate the fraction of aerosol surface covered with liquid water solution as a function of RH.

  6. Reduction in biomass burning aerosol light absorption upon humidification: roles of inorganically-induced hygroscopicity, particle collapse, and photoacoustic heat and mass transfer

    Science.gov (United States)

    Lewis, K. A.; Arnott, W. P.; Moosmüller, H.; Chakrabarty, R. K.; Carrico, C. M.; Kreidenweis, S. M.; Day, D. E.; Malm, W. C.; Laskin, A.; Jimenez, J. L.; Ulbrich, I. M.; Huffman, J. A.; Onasch, T. B.; Trimborn, A.; Liu, L.; Mishchenko, M. I.

    2009-11-01

    Smoke particle emissions from the combustion of biomass fuels typical for the western and southeastern United States were studied and compared under high humidity and ambient conditions in the laboratory. The fuels used were Montana ponderosa pine (Pinus ponderosa), southern California chamise (Adenostoma fasciculatum), and Florida saw palmetto (Serenoa repens). Information on the non-refractory chemical composition of biomass burning aerosol from each fuel was obtained with an aerosol mass spectrometer and through estimation of the black carbon concentration from light absorption measurements at 870 nm. Changes in the optical and physical particle properties under high humidity conditions were observed for hygroscopic smoke particles containing substantial inorganic mass fractions that were emitted from combustion of chamise and palmetto fuels. Light scattering cross sections increased under high humidity for these particles, consistent with the hygroscopic growth measured for 100 nm particles in HTDMA measurements. Photoacoustic measurements of aerosol light absorption coefficients revealed a 20% reduction with increasing relative humidity, contrary to the expectation of light absorption enhancement by the liquid coating taken up by hygroscopic particles. This reduction is hypothesized to arise from two mechanisms: (1) shielding of inner monomers after particle consolidation or collapse with water uptake; (2) the lower case contribution of mass transfer through evaporation and condensation at high relative humidity (RH) to the usual heat transfer pathway for energy release by laser-heated particles in the photoacoustic measurement of aerosol light absorption. The mass transfer contribution is used to evaluate the fraction of aerosol surface covered with liquid water solution as a function of RH.

  7. Targeted Sequencing Reveals Large-Scale Sequence Polymorphism in Maize Candidate Genes for Biomass Production and Composition.

    Directory of Open Access Journals (Sweden)

    Moses M Muraya

    Full Text Available A major goal of maize genomic research is to identify sequence polymorphisms responsible for phenotypic variation in traits of economic importance. Large-scale detection of sequence variation is critical for linking genes, or genomic regions, to phenotypes. However, due to its size and complexity, it remains expensive to generate whole genome sequences of sufficient coverage for divergent maize lines, even with access to next generation sequencing (NGS technology. Because methods involving reduction of genome complexity, such as genotyping-by-sequencing (GBS, assess only a limited fraction of sequence variation, targeted sequencing of selected genomic loci offers an attractive alternative. We therefore designed a sequence capture assay to target 29 Mb genomic regions and surveyed a total of 4,648 genes possibly affecting biomass production in 21 diverse inbred maize lines (7 flints, 14 dents. Captured and enriched genomic DNA was sequenced using the 454 NGS platform to 19.6-fold average depth coverage, and a broad evaluation of read alignment and variant calling methods was performed to select optimal procedures for variant discovery. Sequence alignment with the B73 reference and de novo assembly identified 383,145 putative single nucleotide polymorphisms (SNPs, of which 42,685 were non-synonymous alterations and 7,139 caused frameshifts. Presence/absence variation (PAV of genes was also detected. We found that substantial sequence variation exists among genomic regions targeted in this study, which was particularly evident within coding regions. This diversification has the potential to broaden functional diversity and generate phenotypic variation that may lead to new adaptations and the modification of important agronomic traits. Further, annotated SNPs identified here will serve as useful genetic tools and as candidates in searches for phenotype-altering DNA variation. In summary, we demonstrated that sequencing of captured DNA is a powerful

  8. Multifunctional landscapes: Site characterization and field-scale design to incorporate biomass production into an agricultural system

    Energy Technology Data Exchange (ETDEWEB)

    Ssegane, Herbert; Negri, M. Cristina; Quinn, John; Urgun-Demirtas, Meltem

    2015-09-01

    Current and future demand for food, feed, fiber, and energy require novel approaches to land management, which demands that multifunctional landscapes are created to integrate various ecosystem functions into a sustainable land use. We developed an approach to design such landscapes at a field scale to minimize concerns of land use change, water quality, and greenhouse gas emissions associated with production of food and bioenergy. This study leverages concepts of nutrient recovery and phytoremediation to place bioenergy crops on the landscape to recover nutrients released to watersheds by commodity crops. Crop placement is determined by evaluating spatial variability of: 1) soils, 2) surface flow pathways, 3) shallow groundwater flow gradients, 4) subsurface nitrate concentrations, and 5) primary crop yield. A 0.8 ha bioenergy buffer was designed within a 6.5 ha field to intercept concentrated surface flow, capture and use nitrate leachate, and minimize use of productive areas. Denitrification-Decomposition (DNDC) simulations show that on average, a switchgrass (Panicum Virgatum L.) or willow (Salix spp.) buffer within this catchment according to this design could reduce annual leached NO3 by 61 or 59% and N2O emission by 5.5 or 10.8%, respectively, produce 8.7 or 9.7 Mg ha-1 of biomass respectively, and displace 6.7 Mg ha-1 of corn (Zea mays L.) grain. Therefore, placement of bioenergy crops has the potential to increase environmental sustainability when the pairing of location and crop type result in minimal disruption of current food production systems and provides additional environmental benefits.

  9. Torrefaction of biomass. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-05-15

    occurring even at biomass torrefied at 300 deg. C. Thus it cannot be concluded if pellets of torrefied materials can be stored outside or not. Due to the fact that the densification process will also have big influence on this property and full scale testing with more materials is required before this can be concluded. Densification of torrefied material was tested in both bench scale as well as lab scale pellet presses and revealed larger challenges than expected. Torrefied material reveals a much higher friction, internal between particles as well as external with the die surface, than untreated biomass does and requires thus higher amounts of energy to compress and push through the dies. Moreover, due to that the chemistry of the binding agents in the biomass is altered by the heat treatment, it is also more challenging to produce pellets with high quality. Elevated die temperatures of above {approx}190 deg. C and usage of lubricating additives such as rape seed oil was shown to clearly improve the pelletisation properties, but more research and optimisation is necessary in the future. While grindability and moisture uptake are important for the usage and storage at the power plants, the densification of torrefied is important for the transport to the plant as it is necessary for increasing the energy density. Due to that devolatilization creates cavities in the material the energy density on a volume bases (GJ/m{sup 3}) is actually lowered during torrefaction. But the remaining torrefied biomass material does have a higher energy density on a mass basis (GJ/kg), and therefore subsequent densification by pelletisation will significantly increase it energy density above that of not treated biomass also on a volume bases. Due to the fact that transport of solid fuels on ships is limited by volume rather that mass, this property is important for the economics of the supply chain. (LN)

  10. Pilot-scale comparison of four duckweed strains from different genera for potential application in nutrient recovery from wastewater and valuable biomass production.

    Science.gov (United States)

    Zhao, Y; Fang, Y; Jin, Y; Huang, J; Bao, S; Fu, T; He, Z; Wang, F; Wang, M; Zhao, H

    2015-01-01

    The application potential of four duckweed strains from four genera, Wolffia globosa 0222, Lemna japonica 0223, Landoltia punctata 0224 and Spirodela polyrhiza 0225, were compared in four parallel pilot-scale wastewater treatment systems for more than 1 year. The results indicated that each duckweed strain had unique potential advantages. Unlike L. japonica 0223 and La. punctata 0224, which grow throughout the year, S. polyrhiza 0225 and W. globosa 0222 do not survive cold weather. For year round performance, L. japonica 0223 was best not only in dry biomass production (6.10 g·m(-2) ·day(-1) ), but also in crude protein (35.50%), total amino acid (26.83%) and phosphorus (1.38%) content, plus recovery rates of total nitrogen (TN), total phosphorus (TP) and CO2 (0.31, 0.085 and 7.76 g·m(-2) ·day(-1) , respectively) and removal rates of TN and TP (0.66 and 0.089 g·m(-2) ·day(-1) , respectively). This strongly demonstrates that L. japonica 0223 performed best in wastewater treatment and protein biomass production. Under nutrient starvation conditions, La. punctata 0224 had the highest starch content (45.84%), dry biomass production (4.81 g·m(-2) ·day(-1) ) and starch accumulation (2.9 g·m(-2) ·day(-1) ), making it best for starch biomass production. W. globosa 0222 and S. polyrhiza 0225 showed increased flavonoid biomass production, with higher total flavonoid content (5.85% and 4.22%, respectively) and high dominant flavonoids (>60%). This study provides useful information for selecting the appropriate local duckweed strains for further application in wastewater treatment and valuable biomass production. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Deactivation of V2O5-WO3-TiO2 SCR catalyst at a biomass-fired combined heat and power plant

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker; Johnsson, Jan Erik

    2005-01-01

    The deactivation of a commercial type V2O5-WO3-TiO2 monolith catalyst under biomass combustion was studied at a full-scale grate-fired power plant burning straw/wood using a slip stream pilot scale reactor. The aerosols in the flue gas consisted of a mixture of potassium chloride and sulphate...... though reactivation is possible, the deactivation rate appears too high for practical use of the SCR process in straw combustion........ Three catalyst elements were exposed at 350 °C, and one element was exposed at 250 °C for comparison. The catalyst activity was measured in the reactor at the exposure temperature by addition of NH3 and extra NO. The activity, in terms of a first-order rate constant, dropped by 52% after about 1140 h...

  12. Small-scale heating events in the solar atmosphere. II. Lifetime, total energy, and magnetic properties

    Science.gov (United States)

    Guerreiro, N.; Haberreiter, M.; Hansteen, V.; Schmutz, W.

    2017-07-01

    Context. Small-scale heating events (SSHEs) are believed to play a fundamental role in understanding the process responsible for heating of the solar corona, the pervading redshifts in the transition region, and the acceleration of spicules. Aims: We determine the properties of the SSHEs and the atmospheric response to them in 3D magnetohydrodynamics (3D-MHD) simulations of the solar atmosphere. Methods: We developed a method for identifying and following SSHEs over their lifetime, and applied it to two simulation models. We identified the locations where the energy dissipation is greatest inside the SSHEs volume, and we traced the SSHEs by following the spatial and temporal evolution of the maximum energy dissipation inside the SSHEs volume. Results: The method is effective in following the SSHEs. We can determine their lifetime, total energy, and properties of the plasma, as well as the magnetic field orientation in the vicinity of the SSHEs. Conclusions: We determine that the SSHEs that have the potential to heat the corona live less than 4 min, and typically the energy they release ranges from 1020 to 1024 erg. In addition, the directional change of the field lines on the two sides of the current sheet constituting the SSHEs ranges from 5° to 15° at the moment of the absolute maximum energy dissipation.

  13. Feasibility Assessment of Using Power Plant Waste Heat in Large Scale Horticulture Facility Energy Supply Systems

    Directory of Open Access Journals (Sweden)

    Min Gyung Yu

    2016-02-01

    Full Text Available Recently, the Korean government has been carrying out projects to construct several large scale horticulture facilities. However, it is difficult for an energy supply to operate stably and economically with only a conventional fossil fuel boiler system. For this reason, several unused energy sources have become attractive and it was found that power plant waste heat has the greatest potential for application in this scenario. In this study, we performed a feasibility assessment of power plant waste heat as an energy source for horticulture facilities. As a result, it was confirmed that there was a sufficient amount of energy potential for the use of waste heat to supply energy to the assumed area. In Dangjin, an horticultural area of 500 ha could be constructed by utilizing 20% of the energy reserves. In Hadong, a horticulture facility can be set up to be 260 ha with 7.4% of the energy reserves. In Youngdong, an assumed area of 65 ha could be built utilizing about 19% of the energy reserves. Furthermore, the payback period was calculated in order to evaluate the economic feasibility compared with a conventional system. The initial investment costs can be recovered by the approximately 83% reduction in the annual operating costs.

  14. Biomass utilisation for combined heat and power generation: Status and perspectives for rural regions. Guelzow expert discussions; Energetische Nutzung von Biomasse mit Kraft-Waerme-Kopplung: Stand der Technik und Perspektiven fuer den laendlichen Raum. Guelzower Fachgespraeche

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Biomass has a high potential but biomass utilisation technologies have not yet reached sufficient maturity for a general breakthrough on the market. Political boundary conditions alone are not sufficient if technical conversion processes are neglected. For the time being, the potential of biomass can not be utilised.

  15. TRMM Latent Heating Retrieval: Applications and Comparisons with Field Campaigns and Large-Scale Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Wei-Kuo; Takayabu, Yukari N.; Lang, Steve; Shige, Shoichi; Olson, William S.; Hou, Arthur; Skofronick-Jackson, Gail; Jiang, Xining; Zhang, Chidong; Lau, William K.; Krishnamurti, T.; Waliser, D.; Grecu, M.; Ciesielski, Paul; Johnson, Richard; Houze, Robert A.; Kakar, R.; Nakamura, K.; Braun, S.; Hagos, Samson M.; Oki, R.; Bhardwaj, A.

    2016-05-05

    Yanai et al. (1973) utilized the meteorological data collected from a sounding network to present a pioneering work on thermodynamic budgets, which are referred to as the apparent heat source (Q1) and apparent moisture sink (Q2). Latent heating (LH) is one of the most dominant terms in Q1. Yanai’s paper motivated the development of satellite-based LH algorithms and provided a theoretical background for imposing large-scale advective forcing into cloud-resolving models (CRMs). These CRM-simulated LH and Q1 data have been used to generate the look-up tables in Tropical Rainfall Measuring Mission (TRMM) LH algorithms. A set of algorithms developed for retrieving LH profiles from TRMM-based rainfall profiles are described and evaluated, including details concerning their intrinsic space-time resolutions. Included in the paper are results from a variety of validation analyses that define the uncertainty of the LH profile estimates. Also, examples of how TRMM-retrieved LH profiles have been used to understand the lifecycle of the MJO and improve the predictions of global weather and climate models as well as comparisons with large-scale analyses are provided. Areas for further improvement of the TRMM products are discussed.

  16. Catalytic heat exchangers for small-scale production of hydrogen - feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Silversand, F. [Catator AB, Lund (Sweden)

    2002-02-01

    A feasibility study concerning heat-exchanger reactors in small-scale production of hydrogen has been performed on the request of Svenskt Gastekniskt Center AB and SWEP International AB. The basic idea is to implement different catalysts into brazed plate-type heat exchangers. This can be achieved by installing catalytic cylinders in the inlet-and outlet ports of the heat exchangers or through treatment of the plates to render them catalytically active. It is also possible to sandwich catalytically active wire meshes between the plates. Experiments concerning steam reforming of methanol and methane have been performed in a micro-reactor to gather kinetic data for modelling purposes. Performance calculations concerning heat exchanger reactors have then been conducted with Catator's generic simulation code for catalytic reactors (CatalystExplorer). The simulations clearly demonstrate the technical performance of these reactors. Indeed, the production rate of hydrogen is expected to be about 10 nm{sup 3}/h per litre of heat exchanger. The corresponding value for a conventional steam-reforming unit is about 1 nm{sup 3}/h or less per litre of reactor volume. Also, the compactness and the high degree of integration together with the possibilities of mass production will give an attractive cost for such units. Depending on the demands concerning the purity of the hydrogen it is possible to add secondary catalytic steps like water-gas shifters, methanation and selective oxidation, into a one-train unit, i.e. to design an all-inclusive design. Such reactors can be used for the supply of hydrogen to fuel cells. The production cost for hydrogen can be cut by 60 - 70% through the utilisation of heat exchanger reactors instead of conventional electrolysis. This result is primarily a result of the high price for electricity compared to the feed stock prices in steam reforming. It is important to verify the performance calculations and the simulation results through

  17. Gasification of Woody Biomass.

    Science.gov (United States)

    Dai, Jianjun; Saayman, Jean; Grace, John R; Ellis, Naoko

    2015-01-01

    Interest in biomass to produce heat, power, liquid fuels, hydrogen, and value-added chemicals with reduced greenhouse gas emissions is increasing worldwide. Gasification is becoming a promising technology for biomass utilization with a positive environmental impact. This review focuses specifically on woody biomass gasification and recent advances in the field. The physical properties, chemical structure, and composition of biomass greatly affect gasification performance, pretreatment, and handling. Primary and secondary catalysts are of key importance to improve the conversion and cracking of tars, and lime-enhanced gasification advantageously combines CO2 capture with gasification. These topics are covered here, including the reaction mechanisms and biomass characterization. Experimental research and industrial experience are investigated to elucidate concepts, processes, and characteristics of woody biomass gasification and to identify challenges.

  18. Experimental investigations of micro-scale flow and heat transfer phenomena by using molecular tagging techniques

    Science.gov (United States)

    Hu, Hui; Jin, Zheyan; Nocera, Daniel; Lum, Chee; Koochesfahani, Manoochehr

    2010-08-01

    Recent progress made in the development of novel molecule-based flow diagnostic techniques, including molecular tagging velocimetry (MTV) and lifetime-based molecular tagging thermometry (MTT), to achieve simultaneous measurements of multiple important flow variables for micro-flows and micro-scale heat transfer studies is reported in this study. The focus of the work described here is the particular class of molecular tagging tracers that relies on phosphorescence. Instead of using tiny particles, especially designed phosphorescent molecules, which can be turned into long-lasting glowing marks upon excitation by photons of appropriate wavelength, are used as tracers for both flow velocity and temperature measurements. A pulsed laser is used to 'tag' the tracer molecules in the regions of interest, and the tagged molecules are imaged at two successive times within the photoluminescence lifetime of the tracer molecules. The measured Lagrangian displacement of the tagged molecules provides the estimate of the fluid velocity. The simultaneous temperature measurement is achieved by taking advantage of the temperature dependence of phosphorescence lifetime, which is estimated from the intensity ratio of the tagged molecules in the acquired two phosphorescence images. The implementation and application of the molecular tagging approach for micro-scale thermal flow studies are demonstrated by two examples. The first example is to conduct simultaneous flow velocity and temperature measurements inside a microchannel to quantify the transient behavior of electroosmotic flow (EOF) to elucidate underlying physics associated with the effects of Joule heating on electrokinematically driven flows. The second example is to examine the time evolution of the unsteady heat transfer and phase changing process inside micro-sized, icing water droplets, which is pertinent to the ice formation and accretion processes as water droplets impinge onto cold wind turbine blades.

  19. Teleconnections, Midlatitude Cyclones and Aegean Sea Turbulent Heat Flux Variability on Daily Through Decadal Time Scales

    Science.gov (United States)

    Romanski, Joy; Romanou, Anastasia; Bauer, Michael; Tselioudis, George

    2013-01-01

    We analyze daily wintertime cyclone variability in the central and eastern Mediterranean during 1958-2001, and identify four distinct cyclone states, corresponding to the presence or absence of cyclones in each basin. Each cyclone state is associated with wind flows that induce characteristic patterns of cooling via turbulent (sensible and latent) heat fluxes in the eastern Mediterranean basin and Aegean Sea. The relative frequency of occurrence of each state determines the heat loss from the Aegean Sea during that winter, with largest heat losses occurring when there is a storm in the eastern but not central Mediterranean (eNOTc), and the smallest occurring when there is a storm in the central but not eastern Mediterranean (cNOTe). Time series of daily cyclone states for each winter allow us to infer Aegean Sea cooling for winters prior to 1985, the earliest year for which we have daily heat flux observations. We show that cyclone states conducive to Aegean Sea convection occurred in 1991/1992 and 1992/1993, the winters during which deep water formation was observed in the Aegean Sea, and also during the mid-1970s and the winters of 1963/1964 and 1968/1969. We find that the eNOTc cyclone state is anticorrelated with the North Atlantic Oscillation (NAO) prior to 1977/1978. After 1977/1978, the cNOTe state is anticorrelated with both the NAO and the North Caspian Pattern (NCP), showing that the area of influence of large scale atmospheric teleconnections on regional cyclone activity shifted from the eastern to the central Mediterranean during the late 1970s. A trend toward more frequent occurrence of the positive phase of the NAO produced less frequent cNOTe states since the late 1970s, increasing the number of days with strong cooling of the Aegean Sea surface waters.

  20. Economic analysis of a small-sized combined heat and power plant using forest biomass in the Republic of Korea

    Science.gov (United States)

    Yeongwan Seo; Han-Sup Han; Edward M. (Ted) Bilek; Jungkee Choi; Dusong Cha; Jungsoo Lee

    2017-01-01

    Economic analysis was conducted on the feasibility of operating a small-sized (500kW/hour) gasification power plant producing heat and electricity in a rural town surrounded by forests in the Republic of Korea. Cost factors that were considered over the plant’s 20-year life included wood procurement, a wood grab loader, a chipper, a chip dryer, a gasifier, a generator...

  1. Biomass Feedstock National User Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Bioenergy research at the Biomass Feedstock National User Facility (BFNUF) is focused on creating commodity-scale feed-stocks from native biomass that meet the needs...

  2. Heat

    CERN Document Server

    Lawrence, Ellen

    2016-01-01

    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  3. Production of methanol/DME from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Ahrenfeldt, J.; Birk Henriksen, U.; Muenster-Swendsen, J.; Fink, A.; Roengaard Clausen, L.; Munkholt Christensen, J.; Qin, K.; Lin, W.; Arendt Jensen, P.; Degn Jensen, A.

    2011-07-01

    In this project the production of DME/methanol from biomass has been investigated. Production of DME/methanol from biomass requires the use of a gasifier to transform the solid fuel to a synthesis gas (syngas) - this syngas can then be catalytically converted to DME/methanol. Two different gasifier types have been investigated in this project: 1) The Two-Stage Gasifier (Viking Gasifier), designed to produce a very clean gas to be used in a gas engine, has been connected to a lab-scale methanol plant, to prove that the gas from the gasifier could be used for methanol production with a minimum of gas cleaning. This was proved by experiments. Thermodynamic computer models of DME and methanol plants based on using the Two-Stage Gasification concept were created to show the potential of such plants. The models showed that the potential biomass to DME/methanol + net electricity energy efficiency was 51-58% (LHV). By using waste heat from the plants for district heating, the total energy efficiencies could reach 87-88% (LHV). 2) A lab-scale electrically heated entrained flow gasifier has been used to gasify wood and straw. Entrained flow gasifiers are today the preferred gasifier type for commercial coal gasification, but little information exists on using these types of gasifiers for biomass gasification. The experiments performed provided quantitative data on product and gas composition as a function of operation conditions. Biomass can be gasified with less oxygen consumption compared to coal. The organic fraction of the biomass that is not converted to gas appears as soot. Thermodynamic computer models of DME and methanol plants based on using entrained flow gasification were created to show the potential of such plants. These models showed that the potential torrefied biomass to DME/methanol + net electricity energy efficiency was 65-71% (LHV). Different routes to produce liquid transport fuels from biomass are possible. They include production of RME (rapeseed oil

  4. Cultivation of Chlorella vulgaris in a pilot-scale photobioreactor using real centrate wastewater with waste glycerol for improving microalgae biomass production and wastewater nutrients removal.

    Science.gov (United States)

    Ren, Hongyan; Tuo, Jinhua; Addy, Min M; Zhang, Renchuan; Lu, Qian; Anderson, Erik; Chen, Paul; Ruan, Roger

    2017-12-01

    To improve nutrients removal from real centrate wastewater and enhance the microalgae biomass production, cultivation of Chlorella vulgaris in lab and a pilot-scale photobioreactor with waste glycerol was studied. The results showed the optimal concentration of the crude glycerol was 1.0gL-1 with the maximum biomass productivity of 460mgL-1d-1 TVS, the maximum lipid content of 27%, the nutrient removal efficiency of all above 86%, due to more balanced C/N ratio. The synergistic relationship between the wastewater-borne bacteria and the microalgae had significant good influence on nutrient removal. In pilot-scale wastewater-based algae cultivation, with 1gL-1 waste glycerol addition, the average biomass production of 16.7gm-2d-1, lipid content of 23.6%, and the removal of 2.4gm-2d-1 NH4+-N, 2.7gm-2d-1 total nitrogen, 3.0gm-2d-1 total phosphorous, and 103.0gm-2d-1 of COD were attained for 34days semi-continuous mode. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Multi-scale simulation of heat and flow in geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ostermeyer, Georg-Peter; Srisupattarawanit, Tarin [Technische Univ. Braunschweig (Germany) Inst. of Dynamics and Vibrations

    2013-03-15

    Geothermal power is a great potential source of energy for the future. Presently there are many projects dealing with geothermal energy worldwide, however exploration and development are generally coupled with high cost and risk, especially for deep geothermal reservoirs. For these reasons, geothermal energy projects require a reliable analysis and prediction of physical behavior. Typical CFD simulation tools could in a way be used, but the computational time is critical and the complexity of reservoirs consisting of fracture systems is strongly limiting. The challenge of geothermal reservoir computation are the multi-scale dynamics in space and time; the space scale may vary from mm to km, while the time scale may vary from milliseconds to say 100 years. From the mathematical point of view, the modeling of reservoirs in this article has been developed using the so-called Cellular Automata method (CA), providing fast computation with resulting acceptable accuracy. The physics of heat and flow modeling is realized in a multi-dimensional model including coupling algorithm techniques. The introduced Cellular Automata formulations are able to describe the dynamics of arbitrary types of reservoir, concerning their short-term and long-term physical behavior. (orig.)

  6. Modeling and measuring neighborhood scale flow, turbulence, and temperature within Chicago heat island

    Science.gov (United States)

    Conry, Patrick; Sharma, Ashish; Leo, Laura; Fernando, H. J. S.; Potosnak, Mark; Hellmann, Jessica

    2013-11-01

    The modeling of urban heat island (UHI) requires a multi-scale approach as it involves numerous physical phenomena spanning a range of scales. We have performed a comprehensive study of Chicago's UHI via coupling of mesoscale Weather Research and Forecasting (WRF) and micro-scale ENVI-met models. The application of the latter model to a Lincoln Park neighborhood and a parallel observational campaign will be the primary focus of this presentation. ENVI-met employs a computational fluid dynamics model to represent heterogeneity of urban areas, providing fine resolution output of UHI dynamics. In the field campaign, two stations located on rooftops of DePaul University buildings were each equipped with a sonic anemometer and vertical array of thermocouples, allowing investigations of spatial variability of flow, turbulent fluxes, and temperature profiles in an urban roughness sublayer. One of these was located above a rooftop garden and the other above a conventional rooftop. Downscaled output from the WRF model or a set of observational data served as initial and boundary conditions for the ENVI-met model. The model's predicative capabilities were assessed through comparison with another set of observational data, and dynamical causes for the model's poor behavior were identified. Funded by NSF Grant No. 0934592 and ND-ECI.

  7. Mechanistic Model for Ash Deposit Formation in Biomass Suspension-Fired Boilers. Part 2: Model Verification by Use of Full Scale Tests

    DEFF Research Database (Denmark)

    Hansen, Stine Broholm; Jensen, Peter Arendt; Jappe Frandsen, Flemming

    2017-01-01

    A model for deposit formation in suspension firing of biomass has been developed. The model describes deposit build-up by diffusion and subsequent condensation of vapors, thermoforesis of aerosols, convective diffusion of small particles, impaction of large particles and reaction. The model...... describes particle sticking or rebound by a combination of the description of (visco)elsatic particles impacting a solid surface and particle capture by a viscous surface. The model is used to predict deposit formation rates measured during tests conducted with probes in full-scale suspension-fired biomass...... boilers. The rates predicted by the model was reasonably able to follow the rates observed in the tests, although with some variation, primarily as overestimations of the deposit formation rates. It is considered that the captive properties of the deposit surface are overestimated. Further examination...

  8. Technologies for small scale wood-fueled combined heat and power systems

    Energy Technology Data Exchange (ETDEWEB)

    Houmann Jakobsen, H.; Houmoeller, S.; Thaaning Pedersen, L.

    1998-01-01

    The aim of this study is to describe and compare different technologies for small cogeneration systems (up to 2-3 MW{sub e}), based on wood as fuel. For decentralized cogeneration, i.e. for recovering energy from saw mill wood wastes or heat supply for small villages, it is vital to know the advantages and disadvantages of the different technologies. Also, for the decision-makers it is of importance to know the price levels of the different technologies. A typical obstacle for small wood cogeneration systems is the installation costs. The specific price (per kW) is usually higher than for larger plants or plants using fossil fuels. For a saw mill choosing between cogeneration and simple heat production, however, the larger installation costs are counter weighed by the sale of electricity, while the fuel consumption is the same. Whether it is profitable or not to invest in cogeneration is often hard to decide. For many years small wood cogeneration systems have been too expensive, leading to the construction of only heat producing systems due to too high price levels of small steam turbines. In recent years a great deal of effort has been put into research and developing of new technologies to replace this traditional steam turbine. Among these are: Steam engines; Stirling engines; Indirectly fired gas turbines; Pressurized down draft combustion. Along with the small scale traditional steam turbines, these technologies will be evaluated in this study. When some or all these technologies are fully developed and commercial, a strong means of reducing the strain on the environment and the greenhouse effect will be available, as the total efficiency is high (up to 90%) and wood is an energy source in balance with nature. (au) EFP-95. 19 refs.

  9. Impact assessment of biomass-based district heating systems in densely populated communities. Part I: Dynamic intake fraction methodology

    Science.gov (United States)

    Petrov, Olga; Bi, Xiaotao; Lau, Anthony

    2015-08-01

    This study contributes to the literature by proposing a novel, state-of-the-art approach to estimate incremental air quality and health impacts of proposed or installed district energy systems (DES), such as the growing biomass-based DES, on the immediately surrounding community where population density varies significantly during day as well as the micrometeorological conditions. Spatial and temporal dynamics of pollutant concentrations at sensitive receptors obtained from modeled actual source emissions, inclusion of site-specific terrain, land use and microclimatic characteristics, population density and breathing rates are examined based on their impacts on the exposure potential expressed by the intake fraction (iF). Overall, results revealed that when those parameters are changing, the increase of iF calculated based on average ambient concentrations at each receptor for the UBC campus for the day and night hours for September 2012, ranges from 6.2% to 43.0%: introducing actual spatial receptor distribution led to 43% increase of iF, combined spatial and population dynamics led to 11.3% increase of iF, while introducing temporal dynamics and varying breathing rates resulted in 6.2% and 21.4% increase in iF respectively, compared to the base case box model where receptors and population were treated as static and uniformly distributed across the modeling domain. It is thus essential to take into consideration temporal and spatial variations of atmospheric conditions and dispersion, population density and varying aspiration rates in accurately assessing the health impacts of DES located at densely populated urban communities.

  10. Generation of large scale field-aligned density irregularities in ionospheric heating experiments. [electromagnetic wave decay

    Science.gov (United States)

    Fejer, J. A.

    1974-01-01

    Threshold and growth rate for stimulated Brillouin scattering are calculated for a uniform magnetoplasma. These are then compared with the threshold and growth rate of a new thermal instability in which the nonlinear Lorentz force felt by the electrons at the beat frequency of the two electromagnetic waves is replaced by a pressure force due to differential heating in the interference pattern of the pump wave and the generated electromagnetic wave. This thermal instability, which is still essentially stimulated Brillouin scattering, has a threshold which is especially low when the propagation vector of the beat wave is almost normal to the magnetic field. The threshold is then considerably lower than the threshold for normal stimulated Brillouin scattering and therefore this new instability is probably responsible for the generation of large scale field aligned irregularities and ionospheric spread F.

  11. Large-scale Reduced MHD Simulations of Coronal Heating via GPGPUs

    Science.gov (United States)

    Lin, L.; Ng, C.; Bhattacharjee, A.

    2010-12-01

    In the last few years, we have performed a number of numerical simulations of a coronal heating model based on three-dimensional (3D) reduced magnetohydrodynamics (RMHD), which is generalized from our 2D model [C. S. Ng and A. Bhattacharjee, Astrophys. J., 675, 899 (2008)]. In this model, random photospheric footpoint motion is applied to obtain converged average coronal heating rates and thus we require very long numerical integrations. Moreover, the formation of very fine current layers in the physical process demands runs with very high resolutions. These requirements become exceedingly difficult on conventional parallel architectures when we attempt to simulate using even higher resolutions. We present here results from a port of our RMHD code to Nvidia CUDA (Compute Unified Device Architecture) for hardware acceleration using general purpose graphics processing units (GPGPUs). The code has been benchmarked on a dedicated research workstation equipped with four Nvidia C2050 GPUs, as well as on two large-scale distributed memory machines: Lincoln/NCSA/TeraGrid and Dirac/NERSC. We will report code performance compared with the original parallel code on each of these systems, which span a variety of hardware generations/capabilities.

  12. Laboratory Performance Evaluation of Residential Scale Gas Engine Driven Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Heiba, Ahmad [ORNL; Mehdizadeh Momen, Ayyoub [ORNL; Mahderekal, Dr. Isaac [Intellichoice Energy, Boulder City, Nevada

    2016-01-01

    Building space cooling is, and until 2040 is expected to continue to be, the single largest use of electricity in the residential sector in the United States (EIA Energy Outlook 2015 .) Increases in electric-grid peak demand leads to higher electricity prices, system inefficiencies, power quality problems, and even failures. Thermally-activated systems, such as gas engine-driven heat pump (GHP), can reduce peak demand. This study describes the performance of a residential scale GHP. It was developed as part of a cooperative research and development agreement (CRADA) that was authorized by the Department of Energy (DOE) between OAK Ridge National Laboratory (ORNL) and Southwest Gas. Results showed the GHP produced 16.5 kW (4.7 RT) of cooling capacity at 35 C (95 F) rating condition with gas coefficient of performance (COP) of 0.99. In heating, the GHP produced 20.2 kW (5.75 RT) with a gas COP of 1.33. The study also discusses other benefits and challenges facing the GHP technology such as cost, reliability, and noise.

  13. Evaluation of alternative approaches for landscape-scale biomass estimation in a mixed-species northern forest

    Science.gov (United States)

    Coeli M. Hoover; Mark J. Ducey; R. Andy Colter; Mariko. Yamasaki

    2018-01-01

    There is growing interest in estimating and mapping biomass and carbon content of forests across large landscapes. LiDAR-based inventory methods are increasingly common and have been successfully implemented in multiple forest types. Asner et al. (2011) developed a simple universal forest carbon estimation method for tropical forests that reduces the amount of required...

  14. Biomass, lipid and fatty acid production in large-scale cultures of the marine macroalga Derbesia tenuissima (Chlorophyta).

    Science.gov (United States)

    Magnusson, Marie; Mata, Leonardo; de Nys, Rocky; Paul, Nicholas A

    2014-08-01

    Biomass productivity was quantified for the marine macroalga Derbesia tenuissima cultivated outdoors at seven stocking densities from 0.25 to 8 g L(-1) for 5 weeks. Total lipids and fatty acid quantity and quality was measured from samples that were freeze-dried, dried by oven (75 °C), food dehydrator (60 °C), or outdoor in the sun (40 °C) or shade (38 °C). Stocking densities of 0.25 to 2 g L(-1) yielded the highest biomass productivities (>20 g dry weight m(-2) day(-1)) with no effect on total lipid quantity (11 %), or fatty acid quantity (5.3 %) or quality at any density tested. However, there was an interactive effect of stocking density and drying technique, with a decrease of up to 40 % in polyunsaturated fatty acids in sun-dried compared to freeze-dried biomass. Notably, while fatty acid and biomass productivity may be inseparable in macroalgae, cultivation conditions have a significant carryover effect in the post-harvest delivery of high-quality bio-oils.

  15. Lundquist Number Scaling of Solar Coronal Heating Due to Random Photospheric Footpoint Motion in a Three-Dimensional Tectonics Model

    Science.gov (United States)

    Lin, L.; Ng, C. S.; Bhattacharjee, A.

    2008-11-01

    We have recently obtained new scaling results in 2D for a ``tectonics model'' of coronal heating which suggest that the heating rate becomes independent of resistivity in a statistical steady state [Ng & Bhattacharjee, Astrophys. J., 675, 899 (2008)]. Here we extend our 2D results to 3D by means of numerical simulations. Random photospheric footpoint motion is applied for a time much longer than the correlation time to obtain converged average coronal heating rates. Simulations are done for different values of the Lundquist number to determine scaling. In the large Lundquist number limit, we recover the case in which the heating rate is independent of the Lundquist number, predicted by previous analysis as well as 2D simulations. In the same limit the average magnetic energy built up by the random footpoint motion saturates at a constant level, apparently limited by nonlinear processes, such as instabilities and/or magnetic reconnection.

  16. Enhanced Forced Convection Heat Transfer using Small Scale Vorticity Concentrations Effected by Flow Driven, Aeroelastically Vibrating Reeds

    Science.gov (United States)

    2016-08-03

    lines). b) For the infinite reed case, a sinusoidal body is shown (thick black line) with images (solid and dashed gray lines). DISTRIBUTION A...ratio of the mean heat transfer through the output plane of a channel with the reed ?̅? to the mean heat transfer through the output plane of a...the flow. This is remarkable, because it means that energy from smaller scales (higher frequencies) is transferred to the lower frequencies within

  17. Assessment of advanced small-scale combined heat and power production

    Energy Technology Data Exchange (ETDEWEB)

    Spitzer, J. [Joanneum Research (Austria)

    1996-12-31

    To increase the share of renewable energy sources, bioenergy has to be used for electricity generation, preferably in combined heat and power (CHP) production systems, besides its traditional use in space heating. The need for small-scale, i.e. below 5 MW{sub el}, CHP production arises from the fact that a considerable portion of the available solid biofuels may not be transported over long distances for economic reasons and that in many cases the heat demand is below 10 MW{sub el} in district heating schemes in communities with less than 10 000 inhabitants. The available technical options have to be assessed with respect to performance, reliability and economy. Such an assessment has been performed in a study where the following options have been compared: Gasification - combustion engine or gas turbine; Combustion - steam turbine/engine; Combustion - hot air turbine; Combustion - Stirling engine. While conventional steam cycle systems are available and reliable they are generally not economical in the power range under consideration. Among the other systems, which are not yet commercially available, the Stirling engine system seems to be attractive in the power range below 500 kW{sub el} and the hot air system could close the gap to the steam cycle systems, i.e. cover the power range between 0.5 and 5.0 MW{sub el}. Gasification schemes seem less suitable: The power generation part (combustion engine and gas turbine) is well established for natural gas, with the combustion engine in the lower (<5 MW{sub el}) and the gas turbine in the higher (>5MW{sub el}) power range. However, the gas quality needed for the operation of a combustion engine requires expensive pre-treatment of the gas from wood gasification so that this scheme is less attractive for the power range under consideration. These conclusions lead to R and D efforts in Austria in two directions: Hot air turbine: A utility demonstration plant is under construction with a power of 1 600 kW{sub el

  18. Experimental Study of a Small Scale Hydraulic System for Mechanical Wind Energy Conversion into Heat

    Directory of Open Access Journals (Sweden)

    Tadas Zdankus

    2016-07-01

    Full Text Available Significant potential for reducing thermal energy consumption in buildings of moderate and cold climate countries lies within wind energy utilisation. Unlike solar irradiation, character of wind speeds in Central and Northern Europe correspond to the actual thermal energy demand in buildings. However, mechanical wind energy undergoes transformation into electrical energy before being actually used as thermal energy in most wind energy applications. The study presented in this paper deals with hydraulic systems, designed for small-scale applications to eliminate the intermediate energy transformation as it converts mechanical wind energy into heat directly. The prototype unit containing a pump, flow control valve, oil tank and piping was developed and tested under laboratory conditions. Results of the experiments showed that the prototype system is highly efficient and adjustable to a broad wind velocity range by modifying the definite hydraulic system resistance. Development of such small-scale replicable units has the potential to promote “bottom-up” solutions for the transition to a zero carbon society.

  19. Fluid Flow and Heat Transport Computation for Power-Law Scaling Poroperm Media

    Directory of Open Access Journals (Sweden)

    Peter Leary

    2017-01-01

    Full Text Available In applying Darcy’s law to fluid flow in geologic formations, it is generally assumed that flow variations average to an effectively constant formation flow property. This assumption is, however, fundamentally inaccurate for the ambient crust. Well-log, well-core, and well-flow empirics show that crustal flow spatial variations are systematically correlated from mm to km. Translating crustal flow spatial correlation empirics into numerical form for fluid flow/transport simulation requires computations to be performed on a single global mesh that supports long-range spatial correlation flow structures. Global meshes populated by spatially correlated stochastic poroperm distributions can be processed by 3D finite-element solvers. We model wellbore-logged Dm-scale temperature data due to heat advective flow into a well transecting small faults in a Hm-scale sandstone volume. Wellbore-centric thermal transport is described by Peclet number Pe ≡ a0φv0/D (a0 = wellbore radius, v0 = fluid velocity at a0, φ = mean crustal porosity, and D = rock-water thermal diffusivity. The modelling schema is (i 3D global mesh for spatially correlated stochastic poropermeability; (ii ambient percolation flow calibrated by well-core porosity-controlled permeability; (iii advection via fault-like structures calibrated by well-log neutron porosity; (iv flow Pe ~ 0.5 in ambient crust and Pe ~ 5 for fault-borne advection.

  20. Comparison of methods to evaluate the fungal biomass in heating, ventilation, and air-conditioning (HVAC) dust.

    Science.gov (United States)

    Biyeyeme Bi Mve, Marie-Jeanne; Cloutier, Yves; Lacombe, Nancy; Lavoie, Jacques; Debia, Maximilien; Marchand, Geneviève

    2016-12-01

    Heating, ventilation, and air-conditioning (HVAC) systems contain dust that can be contaminated with fungal spores (molds), which may have harmful effects on the respiratory health of the occupants of a building. HVAC cleaning is often based on visual inspection of the quantity of dust, without taking the mold content into account. The purpose of this study is to propose a method to estimate fungal contamination of dust in HVAC systems. Comparisons of different analytical methods were carried out on dust deposited in a controlled-atmosphere exposure chamber. Sixty samples were analyzed using four methods: culture, direct microscopic spore count (DMSC), β-N-acetylhexosaminidase (NAHA) dosing and qPCR. For each method, the limit of detection, replicability, and repeatability were assessed. The Pearson correlation coefficients between the methods were also evaluated. Depending on the analytical method, mean spore concentrations per 100 cm2 of dust ranged from 10,000 to 682,000. Limits of detection varied from 120 to 217,000 spores/100 cm2. Replicability and repeatability were between 1 and 15%. Pearson correlation coefficients varied from -0.217 to 0.83. The 18S qPCR showed the best sensitivity and precision, as well as the best correlation with the culture method. PCR targets only molds, and a total count of fungal DNA is obtained. Among the methods, mold DNA amplification by qPCR is the method suggested for estimating the fungal content found in dust of HVAC systems.

  1. Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds

    DEFF Research Database (Denmark)

    Johansen, Joakim Myung; Aho, Martti; Paakkinen, Kari

    2013-01-01

    and partitioning of these elements. Earlier work by the authors on the release of K, Cl, and S from a high-chlorine biomass (corn stover) in a lab-scale setup is, in the present work, supplemented with novel results from a bench-scale fixed bed reactor and a 100kW moving grate pilot facility. The results from......, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co...

  2. Experimental and numerical investigations of a small scale double-reflector concentrating solar system with latent heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Woh, Foong Chee

    2011-07-01

    The main aim of this doctoral thesis is to analyze a small scale double- reflector concentrating solar system with latent heat storage in temperature range 230 to 250 Celsius so that cooking can be done efficiently and effectively in the late evening or at night time. Many solar heat collection systems are based on transportation of heat from the focal point to the storage by a circulating heat transfer fluid. In this study, double-reflector arrangement is designed and tested to heat up the thermal heat storage directly without using any heat transport fluid. This makes the system more simple and easy to fabricate. NaNO3-KNO3 binary mixture is selected as the latent heat storage medium because the melting temperature of around 220 Celsius is in a suitable range.There are several objectives in this study. First of all, characterization of phase change materials has been carried out using differential scanning calorimeter (DSC). Important information such as heat capacity as a function of temperature, melting temperature, solid-solid phase transition temperature, enthalpy of fusion, and enthalpy of solid-solid phase transition can be obtained and used in the phase change numerical simulations.After the characterization and selection of a phase change material, a double-reflector system with thermal energy storage was designed and constructed. In order to test the concept of the design, a reflection system using laser diode technique was used in a smoke chamber. Focal point of the primary reflector was determined experimentally and compared with the theoretical calculations. The latent heat storage unit was filled with the NaNO3-KNO3 binary mixture until 90% full. Copper top plate and fin was used to increase the heat transfer rate into the phase change material. With the double-reflector system, thermal charging of the heat storage was carried out under the sun.Numerical simulations of the thermal charging process have been done using finite element model from COMSOL

  3. Effects of photoperiod on nutrient removal, biomass production, and algal-bacterial population dynamics in lab-scale photobioreactors treating municipal wastewater.

    Science.gov (United States)

    Lee, Chang Soo; Lee, Sang-Ah; Ko, So-Ra; Oh, Hee-Mock; Ahn, Chi-Yong

    2015-01-01

    Effects of photoperiod were investigated in lab-scale photobioreactors containing algal-bacterial consortia to reduce organic nutrients from municipal wastewater. Under three photoperiod conditions (12 h:12 h, 36 h:12 h, and 60 h:12 h dark–light cycles), nutrient removals and biomass productions were measured along with monitoring microbial population dynamics. After a batch operation for 12 days, 59–80% carbon, 35–88% nitrogen, and 43–89% phosphorus were removed from influents, respectively. In this study, carbon removal was related positively to the length of dark cycles, while nitrogen and phosphorus removals inversely. On the contrast, the highest microbial biomass in terms of chlorophyll a, dry cell weight, and algal/bacterial rRNA gene markers was produced under the 12 h:12 h dark–light cycle among the three photoperiods. The results showed 1) simultaneous growths between algae and bacteria in the microbial consortia and 2) efficient nitrogen and phosphorus removals along with high microbial biomass production under prolonged light conditions. Statistical analyses indicated that carbon removal was significantly related to the ratio of bacteria to algae in the microbial consortia along with prolonged dark conditions (p wastewater treatment.

  4. Comparison of Biomass and Lipid Production under Ambient Carbon Dioxide Vigorous Aeration and 3% Carbon Dioxide Condition Among the Lead Candidate Chlorella Strains Screened by Various Photobioreactor Scales

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Naoko [Univ. of Nebraska, Lincoln, NE (United States); Barnes, Austin [Univ. of Nebraska, Lincoln, NE (United States); Jensen, Travis [Univ. of Nebraska, Lincoln, NE (United States); Noel, Eric [Univ. of Nebraska, Lincoln, NE (United States); Andlay, Gunjan [Synaptic Research, Baltimore, MD (United States); Rosenberg, Julian N. [Johns Hopkins Univ., Baltimore, MD (United States); Betenbaugh, Michael J. [Johns Hopkins Univ., Baltimore, MD (United States); Guarnieri, Michael T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Oyler, George A. [Univ. of Nebraska, Lincoln, NE (United States); Johns Hopkins Univ., Baltimore, MD (United States); Synaptic Research, Baltimore, MD (United States)

    2015-09-01

    Chlorella species from the UTEX collection, classified by rDNA-based phylogenetic analysis, were screened based on biomass and lipid production in different scales and modes of culture. Lead candidate strains of C. sorokiniana UTEX 1230 and C. vulgaris UTEX 395 and 259 were compared between conditions of vigorous aeration with filtered atmospheric air and 3% CO2 shake-flask cultivation. We found that the biomass of UTEX 1230 produced 2 times higher at 652 mg L-1 dry weight under both ambient CO2 vigorous aeration and 3% CO2 conditions, while UTEX 395 and 259 under 3% CO2 increased to 3 times higher at 863 mg L-1 dry weight than ambient CO2 vigorous aeration. The triacylglycerol contents of UTEX 395 and 259 increased more than 30 times to 30% dry weight with 3% CO2, indicating that additional CO2 is essential for both biomass and lipid accumulation in UTEX 395 and 259.

  5. From lignocellulosic biomass to lactic- and glycolic-acid oligomers: a gram-scale microwave-assisted protocol.

    Science.gov (United States)

    Carnaroglio, Diego; Tabasso, Silvia; Kwasek, Beata; Bogdal, Dariusz; Gaudino, Emanuela Calcio; Cravotto, Giancarlo

    2015-04-24

    The conversion of lignocellulosic biomass into platform chemicals is the key step in the valorization of agricultural waste. Of the biomass-derived platform chemicals currently produced, lactic acid plays a particularly pivotal role in modern biorefineries as it is a versatile commodity chemical and building block for the synthesis of biodegradable polymers. Microwave-assisted processes that furnish lactic acid avoid harsh depolymerization conditions while cutting down reaction time and energy consumption. We herein report a flash catalytic conversion (2 min) of lignocellulosic biomass into lactic and glycolic acids under microwave irradiation. The batch procedure was successfully adapted to a microwave-assisted flow process (35 mL min(-1) ), with the aim of designing a scalable process with higher productivity. The C2 and C4 units recovered from the depolymerization were directly used as the starting material for a solvent and catalyst-free microwave-assisted polycondensation that afforded oligomers in good yields. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Biomass thesaurus

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-01

    This thesaurus contains the vocabulary used to index the Biomass Database maintained by the IEA Biomass Conversion Technical Information Service. The database, which is used to produce Biomass Abstracts, contains indexed and abstracted references to the published literature relating to biomass energy including cultivations, harvesting, materials handling, conversion techniques, environmental aspects and economics.

  7. Catalyzed steam gasification of biomass. Phase II. Final research report

    Energy Technology Data Exchange (ETDEWEB)

    Hooverman, R.H.

    1979-05-01

    The Wright-Malta gasification process is characterized by low-temperature, catalyzed steam gasification in a pressurized rotary kiln. Fresh biomass moves slowly and continuously through the kiln, where it is gradually heated to around 1200/sup 0/F in an atmosphere of 300 psi steam. During its traverse, pyrolysis and reaction of steam with the nascent char convert nearly all of the organic solids to the gaseous phase. The volatile pyrolysis products pass through the kiln co-currently with the solids and are similarly cracked and steam-reformed within the kiln to fixed gases. Heat for the gasification process is provided by sensible heat recovered from the product gas and the wood decomposition exotherm, making the process inherently very energy-efficient. This report summarizes the work done during the experimental, laboratory-scale phase of development of the W-M biomass gasification process. Two bench-scale experimental gasifiers were constructed and tested: the ''minikiln'', a batch-feed, rotating autoclave; and the ''biogasser'', a stationary, continuous-feed, tubular reactor with zone heating and auger transport. Studies were carried out in these reactors to determine the extent of conversion of biomass solids to gas, and the makeup of the product gas, over a wide range of process conditions. The process variables that were investigated included reactor pressure and temperature, catalyst type and concentration, moisture content and type of biomass feed.

  8. Soil Respiration in Tibetan Alpine Grasslands: Belowground Biomass and Soil Moisture, but Not Soil Temperature, Best Explain the Large-Scale Patterns

    Science.gov (United States)

    Geng, Yan; Wang, Yonghui; Yang, Kuo; Wang, Shaopeng; Zeng, Hui; Baumann, Frank; Kuehn, Peter; Scholten, Thomas; He, Jin-Sheng

    2012-01-01

    The Tibetan Plateau is an essential area to study the potential feedback effects of soils to climate change due to the rapid rise in its air temperature in the past several decades and the large amounts of soil organic carbon (SOC) stocks, particularly in the permafrost. Yet it is one of the most under-investigated regions in soil respiration (Rs) studies. Here, Rs rates were measured at 42 sites in alpine grasslands (including alpine steppes and meadows) along a transect across the Tibetan Plateau during the peak growing season of 2006 and 2007 in order to test whether: (1) belowground biomass (BGB) is most closely related to spatial variation in Rs due to high root biomass density, and (2) soil temperature significantly influences spatial pattern of Rs owing to metabolic limitation from the low temperature in cold, high-altitude ecosystems. The average daily mean Rs of the alpine grasslands at peak growing season was 3.92 µmol CO2 m−2 s−1, ranging from 0.39 to 12.88 µmol CO2 m−2 s−1, with average daily mean Rs of 2.01 and 5.49 µmol CO2 m−2 s−1 for steppes and meadows, respectively. By regression tree analysis, BGB, aboveground biomass (AGB), SOC, soil moisture (SM), and vegetation type were selected out of 15 variables examined, as the factors influencing large-scale variation in Rs. With a structural equation modelling approach, we found only BGB and SM had direct effects on Rs, while other factors indirectly affecting Rs through BGB or SM. Most (80%) of the variation in Rs could be attributed to the difference in BGB among sites. BGB and SM together accounted for the majority (82%) of spatial patterns of Rs. Our results only support the first hypothesis, suggesting that models incorporating BGB and SM can improve Rs estimation at regional scale. PMID:22509373

  9. Soil respiration in Tibetan alpine grasslands: belowground biomass and soil moisture, but not soil temperature, best explain the large-scale patterns.

    Directory of Open Access Journals (Sweden)

    Yan Geng

    Full Text Available The Tibetan Plateau is an essential area to study the potential feedback effects of soils to climate change due to the rapid rise in its air temperature in the past several decades and the large amounts of soil organic carbon (SOC stocks, particularly in the permafrost. Yet it is one of the most under-investigated regions in soil respiration (Rs studies. Here, Rs rates were measured at 42 sites in alpine grasslands (including alpine steppes and meadows along a transect across the Tibetan Plateau during the peak growing season of 2006 and 2007 in order to test whether: (1 belowground biomass (BGB is most closely related to spatial variation in Rs due to high root biomass density, and (2 soil temperature significantly influences spatial pattern of Rs owing to metabolic limitation from the low temperature in cold, high-altitude ecosystems. The average daily mean Rs of the alpine grasslands at peak growing season was 3.92 µmol CO(2 m(-2 s(-1, ranging from 0.39 to 12.88 µmol CO(2 m(-2 s(-1, with average daily mean Rs of 2.01 and 5.49 µmol CO(2 m(-2 s(-1 for steppes and meadows, respectively. By regression tree analysis, BGB, aboveground biomass (AGB, SOC, soil moisture (SM, and vegetation type were selected out of 15 variables examined, as the factors influencing large-scale variation in Rs. With a structural equation modelling approach, we found only BGB and SM had direct effects on Rs, while other factors indirectly affecting Rs through BGB or SM. Most (80% of the variation in Rs could be attributed to the difference in BGB among sites. BGB and SM together accounted for the majority (82% of spatial patterns of Rs. Our results only support the first hypothesis, suggesting that models incorporating BGB and SM can improve Rs estimation at regional scale.

  10. Long-term modelling of Carbon Capture and Storage, Nuclear Fusion, and large-scale District Heating

    DEFF Research Database (Denmark)

    Grohnheit, Poul Erik; Korsholm, Søren Bang; Lüthje, Mikael

    2011-01-01

    on nuclear fusion and the Pan European TIMES model, respectively. In the next decades CCS can be a driver for the development and expansion of large-scale district heating systems, which are currently widespread in Europe, Korea and China, and with large potentials in North America. If fusion will replace...

  11. Regulation for Optimal Liquid Products during Biomass Pyrolysis: A Review

    Science.gov (United States)

    Wang, F.; Hu, L. J.; Zheng, Y. W.; Huang, Y. B.; Yang, X. Q.; Liu, C.; Kang, J.; Zheng, Z. F.

    2016-08-01

    The liquid product obtained from biomass pyrolysis is very valuable that it could be used for extraction of chemicals as well as for liquid fuel. The desire goal is to obtain the most bio-oil with desired higher heating value (HHV), high physicochemical stability. The yields and chemical composition of products from biomass pyrolysis are closely related to the feedstock, pyrolysis parameters and catalysts. Current researches mainly concentrated on the co-pyrolysis of different biomass and introduce of novel catalysts as well as the combined effect of catalysts and pyrolysis parameters. This review starts with the chemical composition of biomass and the fundamental parameters and focuses on the influence of catalysts on bio-oil. What is more, the pyrolysis facilities at commercial scales were also involved. The classic researches and the current literature about the yield and composition of products (mainly liquid products) are summarized.

  12. Building-integrated photobioteactors. An innovative facade system for the sustainable power generation of biomass and heat.; Gebaeudeintegrierte Photobioreaktoren. Ein innovatives Fassadensystem fuer die nachhaltige Energieerzeugung von Biomasse und Waerme

    Energy Technology Data Exchange (ETDEWEB)

    Wurm, Jan [Arup Deutschland GmbH, Berlin (Germany); Schneider, Cornelius

    2012-08-15

    Photobioreactors are closed, translucent hollow bodies filled with a growing medium. This type of reactor creates controlled conditions for biochemical processes of the photosynthesis. The transformation of carbon dioxide and light initiates the production of biomass.

  13. Intermediate pyrolysis of agro-industrial biomasses in bench-scale pyrolyser: Product yields and its characterization.

    Science.gov (United States)

    Tinwala, Farha; Mohanty, Pravakar; Parmar, Snehal; Patel, Anant; Pant, Kamal K

    2015-01-01

    Pyrolysis of woody biomass, agro-residues and seed was carried out at 500 ± 10 °C in a fixed bed pyrolyser. Bio-oil yield was found varying from 20.5% to 47.5%, whereas the biochar and pyrolysis gas ranged from 27.5% to 40% and 24.5% to 40.5%, respectively. Pyrolysis gas was measured for flame temperature along with CO, CO2, H2, CH4 and other gases composition. HHV of biochar (29.4 MJ/kg) and pyrolitic gas (8.6 MJ/kg) of woody biomass was higher analogous to sub-bituminous coal and steam gasification based producer gas respectively, whereas HHV of bio-oil obtained from seed (25.6 MJ/kg) was significantly more than husks, shells and straws. TGA-DTG studies showed the husks as potential source for the pyrolysis. Bio-oils as a major by-product of intermediate pyrolysis have several applications like substitute of furnace oil, extraction of fine chemicals, whereas biochar as a soil amendment for enhancing soil fertility and gases for thermal application. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Solar Thermoelectricity via Advanced Latent Heat Storage: A Cost-Effective Small-Scale CSP Application

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, Greg C.; Rea, J.; Olsen, Michele L.; Oshman, C.; Hardin, C.; Alleman, Jeff; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, Philip A.; Siegel, N. P.; Toberer, Eric S.; Ginley, David S.

    2017-06-27

    We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

  15. Solar thermoelectricity via advanced latent heat storage: A cost-effective small-scale CSP application

    Science.gov (United States)

    Glatzmaier, G. C.; Rea, J.; Olsen, M. L.; Oshman, C.; Hardin, C.; Alleman, J.; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

    2017-06-01

    We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

  16. Characterization of biomass fast pyrolysis. Advantages and drawbacks of different possible criteria

    Energy Technology Data Exchange (ETDEWEB)

    Lede, Jacques [LRGP-CNRS-INPL, 1, rue Grandville, BP 20451, Nancy Cedex (France); Authier, Olivier [LRGP-CNRS-INPL, 1, rue Grandville, BP 20451, Nancy Cedex (France); EDF-R and D, Departement Mecanique des Fluides, Energies et Environnement, 6, quai Watier, BP 49, Chatou Cedex (France)

    2011-09-15

    The literature shows that different possible criteria are used for defining biomass fast pyrolysis. On the basis of a simplified modeling of a cellulose (biomass model compound) particle pyrolysis, the present paper points out that the most often considered parameters (i.e., temperature and heating rate) are inappropriate. They are very difficult to define and measure, and according to their definitions, important errors can be made (kinetic measurements and reactor scaling up). Other possible parameters are also examined such as particle initial size, available heat flux density, heat transfer coefficient, and products elimination efficiency. In order to be able to compare different experimental conditions on a similar basis, it is shown that at the biomass sample level, fast pyrolysis is favoured (enhancement of bio-oil fractions) if two necessary conditions are simultaneously fulfilled. They include high external heat transfer coefficient and efficient products removal. (orig.)

  17. Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development & Performance Analysis

    Science.gov (United States)

    Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan

    2014-01-01

    ATA-002 Technical Team has successfully designed, developed, tested and assessed the SLS Pathfinder propulsion systems for the Main Base Heating Test Program. Major Outcomes of the Pathfinder Test Program: Reach 90% of full-scale chamber pressure Achieved all engine/motor design parameter requirements Reach steady plume flow behavior in less than 35 msec Steady chamber pressure for 60 to 100 msec during engine/motor operation Similar model engine/motor performance to full-scale SLS system Mitigated nozzle throat and combustor thermal erosion Test data shows good agreement with numerical prediction codes Next phase of the ATA-002 Test Program Design & development of the SLS OML for the Main Base Heating Test Tweak BSRM design to optimize performance Tweak CS-REM design to increase robustness MSFC Aerosciences and CUBRC have the capability to develop sub-scale propulsion systems to meet desired performance requirements for short-duration testing.

  18. L-Band SAR Backscatter Related to Forest Cover, Height and Aboveground Biomass at Multiple Spatial Scales across Denmark

    DEFF Research Database (Denmark)

    Joshi, Neha P.; Mitchard, Edward T A; Schumacher, Johannes

    2015-01-01

    DAR-derived maps of vegetation penetrability, height and AGB over Denmark at different spatial scales (50 m to 500 m). Trends in the relations indicate that, first, AGB retrieval accuracy from SAR improves most in mapping at 100-m scale instead of 50 m, and improvements are negligible beyond 250 m. Relative errors...... a strong linear relation (R2 = 0.79 at 250-m scale). In areas of high fractional forest cover, there is a slight decline in backscatter as AGB increases, indicating signal attenuation. The two results demonstrate that accounting for spatial scale and variations in forest structure, such as cover...

  19. Scale analysis of decay heat removal system between HTR-10 and HTR-PM reactors under accidental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, Thiago D.; Alvim, Antonio C.M. [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Lapa, Celso M.F., E-mail: thiagodbtr@gmail.com, E-mail: lapa@ien.gov.br, E-mail: alvim@nuclear.ufrj.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The 10 MW high-temperature gas-cooled test module (HTR-10) is a graphite-moderated and helium-cooled pebble bed reactor prototype that was designed to demonstrate the technical and safety feasibility of this type of reactor project under normal and accidental conditions. In addition, one of the systems responsible for ensuring the safe operation of this type of reactor is the passive decay heat removal system (DHRS), which operates using passive heat removal processes. A demonstration of the heat removal capacity of the DHRS under accidental conditions was analyzed based on a benchmark problem for design-based accidents on an HTR-10, i.e., the pressurized loss of forced cooling (PLOFC) described in technical reports produced by the International Atomic Energy Agency. In fact, the HTR-10 is also a proof-of-concept reactor for the high-temperature gas-cooled reactor pebble-bed module (HTR-PM), which generates approximately 25 times more heat than the HTR-10, with a thermal power of 250 MW, thereby requiring a DHRS with a higher system capacity. Thus, because an HTR-10 is a prototype reactor for an HTR-PM, a scaling analysis of the heat transfer process from the reactor to the DHRS was carried out between the HTR-10 and HTR-PM systems to verify the distortions of scale and the differences between the main dimensionless numbers from the two projects. (author)

  20. Biomass Deconstruction and Recalcitrance

    DEFF Research Database (Denmark)

    Zhang, Heng

    This thesis is about the use of an agricultural residue as a feedstock for fermentable sugars to be used for second generation (2G) bioethanol. The main focus of this thesis work is upon the recalcitrance of different anatomical fractions of wheat straw. Biomass recalcitrance is a collective...... system, a plate incubator and a high performance liquid chromatography (HPLC) system. In comparison with the reported HTS platforms, the Copenhagen platform is featured by the fully automatic biomass sample preparation system, the bench-scale hydrothermal pretreatment setup, and precise sugar measurement...... level of different biomasses. The knowledge on wheat straw biomass gained from this thesis work may be translated to more focused plant breeding research for 2G ethanol production, and the Copenhagen HTS platform is an ideal tool for screening large biomass sample set. The success of lignocellulosic...

  1. Aerosols upwind of Mexico City during the MILAGRO campaign: regional scale biomass burning, dust and volcanic ash from aircraft measurements

    Science.gov (United States)

    Junkermann, W.; Steinbrecher, R.

    2009-04-01

    During the MILAGRO Campaign March/April 2006 a series of aircraft flights with the FZK microlight D-MIFU were performed in the area southeast of Mexico City starting from Puebla airport, circling the national park area of Ixtachiuatl and Popocatepetl and scanning the Chalco valley down to Cuautla in the Cuernavaca province. All flights were combined with vertical profiles up to 4500 m a.s.l. in several locations, typically north of volcano Ixtachiuatl on the Puebla side, above Chalco or Tenago del Aire and south of volcano Popocatepetl, either at Cuautla or Atlixco. In Tenango del Aire a ceilometer was additionally operated continuously for characterization of the planetary boundary layer. The aircraft carried a set of aerosol instrumentation, fine and coarse particles and size distributions as well as a 7 wavelength aethalometer. Additionally meteorological parameters, temperature and dewpoint, global radiation and actinic radiation balance, respectively photolysis rates, and ozone concentrations were measured. The instrumentation allowed to characterize the aerosol according to their sources and also their impact on radiation transfer. Biomass burning aerosol, windblown dust and volcanic ash were identified within the upwind area of Mexico City with large differences between the dry season in the first weeks of the campaign and the by far cleaner situation after beginning thunderstorm activity towards the end of the campaign. Also the aerosol characteristics inside and outside the Mexico City basin were often completely different. With wind speeds of ~ 5 m/sec from southerly directions in the Chalco valley the aerosol mixture can reach the City within ~ 2 h. Rural aerosol mixtures from the Cuernavaca plain were mixed during the transport with dust from the MC basin. Very high intensity biomass burning plumes normally reached higher altitudes and produced pyrocumulus clouds. These aerosols were injected mainly into the free troposphere. Within the MC basin a large

  2. Textural and rheological properties of Pacific whiting surimi as affected by nano-scaled fish bone and heating rates.

    Science.gov (United States)

    Yin, Tao; Park, Jae W

    2015-08-01

    Textural and rheological properties of Pacific whiting (PW) surimi were investigated at various heating rates with the use of nano-scaled fish bone (NFB) and calcium chloride. Addition of NFB and slow heating improved gel strength significantly. Activity of endogenous transglutaminase (ETGase) from PW surimi was markedly induced by both NFB calcium and calcium chloride, showing an optimal temperature at 30°C. Initial storage modulus increased as NFB calcium concentration increased and the same trend was maintained throughout the temperature sweep. Rheograms with temperature sweep at slow heating rate (1°C/min) exhibited two peaks at ∼ 35°C and ∼ 70°C. However, no peak was observed during temperature sweep from 20 to 90°C at fast heating rate (20°C/min). Protein patterns of surimi gels were affected by both heating rate and NFB calcium concentration. Under slow heating, myosin heavy chain intensity decreased with NFB calcium concentration, indicating formation of ε-(γ-glutamyl) lysine cross-links by ETGase and NFB calcium ion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effects of operation parameters on nutrient removal from wastewater and high-protein biomass production in a duckweed-based (Lemma aequinoctialis) pilot-scale system.

    Science.gov (United States)

    Zhao, Yonggui; Fang, Yang; Jin, Yanling; Huang, Jun; Bao, Shu; He, Zhiming; Wang, Feng; Zhao, Hai

    2014-01-01

    The effects of water depth, coverage rate and harvest regime on nutrient removal from wastewater and high-protein biomass production were assessed in a duckweed-based (Lemna aequinoctialis) pilot-scale wastewater treatment system (10 basins × 12 m(2)) that is located near Dianchi Lake in China. The results indicated that a water depth of 50 cm, a coverage rate of 150% and a harvest regime of 4 days were preferable conditions, under which excellent records of high-protein duckweed (dry matter production of 6.65 g/m(2)/d with crude protein content of 36.16% and phosphorus content of 1.46%) were obtained at a temperature of 12-21 °C. At the same time, the system achieved a removal efficiency of 66.16, 23.1, 48.3 and 76.52% for NH4(+)-N, TN, TP and turbidity, respectively, with the considerable removal rate of 0.465 g/m(2)/d for TN and 0.134 g/m(2)/d for TP at a hydraulic retention time of 6 days. In additionally, it was found that a lower duckweed density could lead to higher dissolved oxygen in the water and then a higher removal percentage of NH4(+)-N by nitrobacteria. This study obtains the preferable operation conditions for wastewater treatment and high-protein biomass production in a duckweed-based pilot-scale system, supplying an important reference for further large-scale applications of duckweed.

  4. Summer heat waves over western Europe 1880-2003, their relationship to large-scale forcings and predictability

    Energy Technology Data Exchange (ETDEWEB)

    Della-Marta, P.M. [University of Bern, Institute of Geography, Climatology and Meteorology Research Group, Bern (Switzerland); Federal Office for Meteorology and Climatology MeteoSwiss, Zurich (Switzerland); National Climate Center, Bureau of Meteorology, Melbourne (Australia); Luterbacher, J.; Xoplaki, E.; Wanner, H. [University of Bern, Institute of Geography, Climatology and Meteorology Research Group, Bern (Switzerland); NCCR Climate, Bern (Switzerland); Weissenfluh, H. von [University of Bern, Institute of Geography, Climatology and Meteorology Research Group, Bern (Switzerland); Brunet, M. [University Rovira i Virgili, Climate Change Research Group, Tarragona (Spain)

    2007-08-15

    We investigate the large-scale forcing and teleconnections between atmospheric circulation (sea level pressure, SLP), sea surface temperatures (SSTs), precipitation and heat wave events over western Europe using a new dataset of 54 daily maximum temperature time series. Forty four of these time series have been homogenised at the daily timescale to ensure that the presence of inhomogeneities has been minimised. The daily data have been used to create a seasonal index of the number of heat waves. Using canonical correlation analysis (CCA), heat waves over western Europe are shown to be related to anomalous high pressure over Scandinavia and central western Europe. Other forcing factors such as Atlantic SSTs and European precipitation, the later as a proxy for soil moisture, a known factor in strengthening land-atmosphere feedback processes, are also important. The strength of the relationship between summer SLP anomalies and heat waves is improved (from 35%) to account for around 46% of its variability when summer Atlantic and Mediterranean SSTs and summer European precipitation anomalies are included as predictors. This indicates that these predictors are not completely collinear rather that they each have some contribution to accounting for summer heat wave variability. However, the simplicity and scale of the statistical analysis masks this complex interaction between variables. There is some useful predictive skill of summer heat waves using multiple lagged predictors. A CCA using preceding winter North Atlantic SSTs and preceding January to May Mediterranean total precipitation results in significant hindcast (1972-2003) Spearman rank correlation skill scores up to 0.55 with an average skill score over the domain equal to 0.28 {+-} 0.28. In agreement with previous studies focused on mean summer temperature, there appears to be some predictability of heat wave events on the decadal scale from the Atlantic Multidecadal Oscillation (AMO), although the long

  5. Summer heat waves over western Europe 1880 2003, their relationship to large-scale forcings and predictability

    Science.gov (United States)

    Della-Marta, P. M.; Luterbacher, J.; von Weissenfluh, H.; Xoplaki, E.; Brunet, M.; Wanner, H.

    2007-08-01

    We investigate the large-scale forcing and teleconnections between atmospheric circulation (sea level pressure, SLP), sea surface temperatures (SSTs), precipitation and heat wave events over western Europe using a new dataset of 54 daily maximum temperature time series. Forty four of these time series have been homogenised at the daily timescale to ensure that the presence of inhomogeneities has been minimised. The daily data have been used to create a seasonal index of the number of heat waves. Using canonical correlation analysis (CCA), heat waves over western Europe are shown to be related to anomalous high pressure over Scandinavia and central western Europe. Other forcing factors such as Atlantic SSTs and European precipitation, the later as a proxy for soil moisture, a known factor in strengthening land atmosphere feedback processes, are also important. The strength of the relationship between summer SLP anomalies and heat waves is improved (from 35%) to account for around 46% of its variability when summer Atlantic and Mediterranean SSTs and summer European precipitation anomalies are included as predictors. This indicates that these predictors are not completely collinear rather that they each have some contribution to accounting for summer heat wave variability. However, the simplicity and scale of the statistical analysis masks this complex interaction between variables. There is some useful predictive skill of summer heat waves using multiple lagged predictors. A CCA using preceding winter North Atlantic SSTs and preceding January to May Mediterranean total precipitation results in significant hindcast (1972 2003) Spearman rank correlation skill scores up to 0.55 with an average skill score over the domain equal to 0.28 ± 0.28. In agreement with previous studies focused on mean summer temperature, there appears to be some predictability of heat wave events on the decadal scale from the Atlantic Multidecadal Oscillation (AMO), although the long

  6. Biomass pretreatment

    Science.gov (United States)

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  7. 3d X-Y scaling of the specific heat of YBa 2Cu 3O 7-δ single crystals

    Science.gov (United States)

    Overend, Neil; Howson, Mark A.; Lawrie, Ian D.

    1994-12-01

    The specific heat of a single crystal sample of YBa 2Cu 3O 7-δ (YBCO) has been measured with magnetic fields up to 8 Tesla applied parallel to the c-axis of the crystal. We analyse the data in terms of the Lowest Landau Level (LLL) and critical scaling theories. Recent measurements of magnetisation and resistivity have been unable to distinguish between the critical scaling and LLL regimes. We find that the data does not scale using the LLL theory and therefore conclude that the LLL theory is not applicable in magnetic fields less than 8 Tesla. However, we find that the data does scale using the 3-dimensional XY model. This provides strong evidence for the existence of a critical regime within which there is scaling behaviour characteristic of the 3-dimensional XY model with critical exponents consistent with those observed in superfluid 4He.

  8. Structure-mechanical function relations at nano-scale in heat-affected human dental tissue.

    Science.gov (United States)

    Sui, Tan; Sandholzer, Michael A; Le Bourhis, Eric; Baimpas, Nikolaos; Landini, Gabriel; Korsunsky, Alexander M

    2014-04-01

    The knowledge of the mechanical properties of dental materials related to their hierarchical structure is essential for understanding and predicting the effect of microstructural alterations on the performance of dental tissues in the context of forensic and archaeological investigation as well as laser irradiation treatment of caries. So far, few studies have focused on the nano-scale structure-mechanical function relations of human teeth altered by chemical or thermal treatment. The response of dental tissues to thermal treatment is thought to be strongly affected by the mineral crystallite size, their spatial arrangement and preferred orientation. In this study, synchrotron-based small and wide angle X-ray scattering (SAXS/WAXS) techniques were used to investigate the micro-structural alterations (mean crystalline thickness, crystal perfection and degree of alignment) of heat-affected dentine and enamel in human dental teeth. Additionally, nanoindentation mapping was applied to detect the spatial and temperature-dependent nano-mechanical properties variation. The SAXS/WAXS results revealed that the mean crystalline thickness distribution in dentine was more uniform compared with that in enamel. Although in general the mean crystalline thickness increased both in dentine and enamel as the temperature increased, the local structural variations gradually reduced. Meanwhile, the hardness and reduced modulus in enamel decreased as the temperature increased, while for dentine, the tendency reversed at high temperature. The analysis of the correlation between the ultrastructure and mechanical properties coupled with the effect of temperature demonstrates the effect of mean thickness and orientation on the local variation of mechanical property. This structural-mechanical property alteration is likely to be due to changes of HAp crystallites, thus dentine and enamel exhibit different responses at different temperatures. Our results enable an improved understanding of

  9. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    The present Ph. D. thesis describes experimental and modeling investigations on entrained flow gasification of biomass and an experimental investigation on entrained flow cogasification of biomass and coal. A review of the current knowledge of biomass entrained flow gasification is presented....... Biomass gasification experiments were performed in a laboratory-scale atmospheric pressure entrained flow reactor with the aim to investigate the effects of operating parameters and biomass types on syngas products. A wide range of operating parameters was involved: reactor temperature, steam/carbon ratio......, excess air ratio, oxygen concentration, feeder gas flow, and residence time. Wood, straw, and lignin were used as biomass fuels. In general, the carbon conversion was higher than 90 % in the biomass gasification experiments conducted at high temperatures (> 1200 °C). The biomass carbon...

  10. Pilot-Scale Biorefinery: Sustainable Transport Fuels from Biomass via Integrated Pyrolysis and Catalytic Hydroconversion - Wastewater Cleanup by Catalytic Hydrothermal Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Olarte, Mariefel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, Todd R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-19

    DOE-EE Bioenergy Technologies Office has set forth several goals to increase the use of bioenergy and bioproducts derived from renewable resources. One of these goals is to facilitate the implementation of the biorefinery. The biorefinery will include the production of liquid fuels, power and, in some cases, products. The integrated biorefinery should stand-alone from an economic perspective with fuels and power driving the economy of scale while the economics/profitability of the facility will be dependent on existing market conditions. UOP LLC proposed to demonstrate a fast pyrolysis based integrated biorefinery. Pacific Northwest National Laboratory (PNNL) has expertise in an important technology area of interest to UOP for use in their pyrolysis-based biorefinery. This CRADA project provides the supporting technology development and demonstration to allow incorporation of this technology into the biorefinery. PNNL developed catalytic hydrothermal gasification (CHG) for use with aqueous streams within the pyrolysis biorefinery. These aqueous streams included the aqueous phase separated from the fast pyrolysis bio-oil and the aqueous byproduct streams formed in the hydroprocessing of the bio-oil to finished products. The purpose of this project was to demonstrate a technically and economically viable technology for converting renewable biomass feedstocks to sustainable and fungible transportation fuels. To demonstrate the technology, UOP constructed and operated a pilot-scale biorefinery that processed one dry ton per day of biomass using fast pyrolysis. Specific objectives of the project were to: The anticipated outcomes of the project were a validated process technology, a range of validated feedstocks, product property and Life Cycle data, and technical and operating data upon which to base the design of a full-scale biorefinery. The anticipated long-term outcomes from successful commercialization of the technology were: (1) the replacement of a significant

  11. Pore-scale studies of interphase mass and heat transfer during two-phase flow in porous media

    Science.gov (United States)

    Hassanizadeh, S. M.; Karadimitriou, N.; Zhang, Q.; Nuske, P.

    2015-12-01

    Micro-models have been proven to be a valuable tool in porous media studies by allowing the observation of flow and transport on the micro-scale. They help to increase our insight of flow and transport phenomena on both micro- and macro-scales. A micro-model is an artificial representation of a porous medium, made of a transparent material. We have used Poly-Di-Methyl-Siloxane (PDMS), which is a viscoelastic, silicon-based organic polymer. It is optically transparent, inert, non-toxic, and non-flammable. We have studied capillary phenomena, colloid transport, and heat transfer during two-phase flow. We have shown that capillarity phenomena are controlled by fluid-fluid interfaces at the micro-scale. In colloid transport experiments, we directly observe colloids movement, their retention at interfaces, and mobilization with the moving interface and contact lines. We have also performed heat transport experiments where the two fluids have distinctly different temperatures at the pore scale. Under such conditions, fluid-fluid interfaces play a major role in heat transport processes. Our results suggest that average fluid-fluid interfacial area could be an important state variable for the macroscale description of two-phase flow and transport processes.

  12. Economic analysis of the renovation of small-scale district heating systems-4 Lithuanian case studies

    Energy Technology Data Exchange (ETDEWEB)

    Dzenajaviciene, E.F. [Laboratory of Regional Energy Development, Lithuanian Energy Institute, Breslaujos 3, LT-44403, Kaunas (Lithuania)]. E-mail: farida@mail.lei.lt; Kveselis, V. [Laboratory of Regional Energy Development, Lithuanian Energy Institute, Breslaujos 3, LT-44403, Kaunas (Lithuania)]. E-mail: vkv@mail.lei.lt; McNaught, C. [Future Energy Solutions from AEA Technology, Harwell, Didcot Oxfordshire OX110QJ (United Kingdom)]. E-mail: colin.mcnaught@aeat.co.uk; Tamonis, M. [Laboratory of Regional Energy Development, Lithuanian Energy Institute, Breslaujos 3, LT-44403, Kaunas (Lithuania)]. E-mail: etpl@mail.lei.lt

    2007-04-15

    This paper describes the renovation and replacement problems of small district heating systems (DHS), which are characteristic to small towns in Lithuania and other Central and East European (CEE) countries. These problems have been scarcely investigated till present and are still the subject of acute energy policy discussions. The focus of this paper is economic analysis of heat generation costs with the aim to get an answer to the question: whether existing small DHS should be renovated or replaced by individual heating systems. The paper gives an economic analysis of heat generating costs for various technological solutions and capacities suitable for the needs of heat consumers in small towns. The analysis includes long-run heat generating costs in natural gas and biofuel boiler houses and CHP installations, including individual buildings and small DHS. Four small towns in Lithuania with the population below 40,000 were selected for the economic analysis. The economic, financial and technical state of DHS operated in these towns is different and reflects the diversity of DHS in Lithuania. The least cost heat-generating solutions for individual and district heating were investigated. The barriers for market penetration of new technologies were disclosed under Lithuania's conditions. The findings can also be useful for other CEE countries with similar problems.

  13. Economic feasibility of microalgal bacterial floc production for wastewater treatment and biomass valorization: A detailed up-to-date analysis of up-scaled pilot results.

    Science.gov (United States)

    Vulsteke, Elien; Van Den Hende, Sofie; Bourez, Lode; Capoen, Henk; Rousseau, Diederik P L; Albrecht, Johan

    2017-01-01

    The economic potential of outdoor microalgal bacterial floc (MaB-floc) raceway ponds as wastewater treatment technology and bioresource of biomass for fertilizer, shrimp feed, phycobiliproteins and biogas in Northwest Europe is assessed. This assessment is based on cost data provided by industry experts, on experimental data obtained from pilot-scale outdoor MaB-floc ponds treating aquaculture and food-industry effluents, and from different biomass valorization tests. MaB-floc ponds exhibit a cost-performance of EUR 0.25-0.50m-3 wastewater which is similar to conventional wastewater treatment technologies. The production cost of MaB-flocs in aquaculture and food industry effluent is EUR 5.29 and 8.07kg-1TSS, respectively. Capital costs and pond mixing costs are the major expenses. Commercializing MaB-flocs as aquaculture feed generates substantial revenues, but the largest profit potential lies in production of high-purity phycobiliproteins from MaB-flocs. These results highlight the large economic potential of MaB-floc technology, and justify its further development. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A large-scale sensitivity study of urban heat islands using GFDL's earth system model

    Science.gov (United States)

    Li, D.; Gu, Y.

    2016-12-01

    Most previous sensitivity studies of urban heat islands focus on the impact of surface characteristics (including urban geometry and material properties). In this study, we analyze the influence of atmospheric forcing on simulated urban heat islands over the Continental United States (CONUS) using GFDL's earth system model coupled with a newly developed urban canopy model, with a specific focus on the impact of precipitation. It is shown that in summer the simulated urban heat islands generally increase with increasing precipitation amount over the CONUS while in winter precipitation has little impact on the simulated urban heat islands. From a simulation perspective, changing both atmospheric forcing and surface characteristics has important impacts on the simulated urban heat islands and the relative importance varies spatially. Similarly, the relative importance of precipitation among all atmospheric forcing variables varies spatially. Hotspots where precipitation is particularly important are identified.

  15. Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

    Science.gov (United States)

    2016-08-01

    Small-Scale W912H0-12-C-0059 Organic Rankine Cycle (ORC) Engine /Generator Technology 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( SI 5d...same fuel input. This value is used for calculation of Greenhouse Gas (GHG) reductions and economic results. Life cycle economics of the system are...associated with engine and other electric generator systems , waste heat from steam or heat distribution, waste heat from boiler exhausts, and heat

  16. Fiscalini Farms Biomass Energy Project

    Energy Technology Data Exchange (ETDEWEB)

    William Stringfellow; Mary Kay Camarillo; Jeremy Hanlon; Michael Jue; Chelsea Spier

    2011-09-30

    waste heat and better documentation of potential of carbon credits, would also improve the economic outlook. Analysis of baseline operational conditions indicated that a reduction in methane emissions and other greenhouse gas savings resulted from implementation of the project. The project results indicate that using anaerobic digestion to produce bio-methane from agricultural biomass is a promising source of electricity, but that significant challenges need to be addressed before dairy-based biomass energy production can be fully integrated into an alternative energy economy. The biomass energy facility was found to be operating undercapacity. Economic analysis indicated a positive economic sustainability, even at the reduced power production levels demonstrated during the baseline period. However, increasing methane generation capacity (via the importation of biomass codigestate) will be critical for increasing electricity output and improving the long-term economic sustainability of the operation. Dairy-based biomass energy plants are operating under strict environmental regulations applicable to both power-production and confined animal facilities and novel approached are being applied to maintain minimal environmental impacts. The use of selective catalytic reduction (SCR) for nitrous oxide control and a biological hydrogen sulfide control system were tested at this facility. Results from this study suggest that biomass energy systems can be compliant with reasonable scientifically based air and water pollution control regulations. The most significant challenge for the development of biomass energy as a viable component of power production on a regional scale is likely to be the availability of energy-rich organic feedstocks. Additionally, there needs to be further development of regional expertise in digester and power plant operations. At the Fiscalini facility, power production was limited by the availability of biomass for methane generation, not the designed

  17. Biomass Logistics

    Energy Technology Data Exchange (ETDEWEB)

    J. Richard Hess; Kevin L. Kenney; William A. Smith; Ian Bonner; David J. Muth

    2015-04-01

    Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in quantifying multi-factor sustainability limits to increase removal rate as guided by sustainable residue removal plans, and mitigating soil contamination through targeted removal rates based on soil type and residue type/fraction is allowing the use of new high efficiency harvesting equipment and methods. As another consideration, single pass harvesting and other technologies that improve harvesting costs cause biomass storage moisture management challenges, which challenges are further perturbed by annual variability in biomass moisture content. Monitoring, sampling, simulation, and analysis provide basis for moisture, time, and quality relationships in storage, which has allowed the development of moisture tolerant storage systems and best management processes that combine moisture content and time to accommodate baled storage of wet material based upon “shelf-life.” The key to improving biomass supply logistics costs has been developing the associated agronomic sustainability and biomass quality technologies and processes that allow the implementation of equipment engineering solutions.

  18. A Medium-Scale 50 MWfuel Biomass Gasification Based Bio-SNG Plant: A Developed Gas Cleaning Process

    Directory of Open Access Journals (Sweden)

    Ramiar Sadegh-Vaziri

    2015-06-01

    Full Text Available Natural gas is becoming increasingly important as a primary energy source. A suitable replacement for fossil natural gas is bio-SNG, produced by biomass gasification, followed by methanation. A major challenge is efficient gas cleaning processes for removal of sulfur compounds and other impurities. The present study focuses on development of a gas cleaning step for a product gas produced in a 50 MWfuel gasification system. The developed gas cleaning washing process is basically a modification of the Rectisol process. Several different process configurations were evaluated using Aspen plus, including PC-SAFT for the thermodynamic modeling. The developed configuration takes advantage of only one methanol wash column, compared to two columns in a conventional Rectisol process. Results from modeling show the ability of the proposed configuration to remove impurities to a sufficiently low concentrations - almost zero concentration for H2S, CS2, HCl, NH3 and HCN, and approximately 0.01 mg/Nm3 for COS. These levels are acceptable for further upgrading of the gas in a methanation process. Simultaneously, up to 92% of the original CO2 is preserved in the final cleaned syngas stream. No process integration or economic consideration was performed within the scope of the present study, but will be investigated in future projects to improve the overall process.

  19. Hydrogen from biomass: large-scale hydrogen production based on a dual fluidized bed steam gasification system

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Stefan; Stidl, Martin; Proell, Tobias; Rauch, Reinhard; Hofbauer, Hermann [Vienna University of Technology, Institute of Chemical Engineering-Future Energy Technology, Vienna (Austria)

    2011-03-15

    Hydrogen is used as an important feedstock for the chemical industry. Common production technologies for the production of hydrogen from fossil fuels today cause relevant CO{sub 2} emissions. Hydrogen from renewable energy sources is discussed as an alternative option to replace traditional feedstock and can therefore be part of a low-carbon energy system. This paper describes the results of a simulation of a concept for the production of hydrogen with biomass as feedstock. The described investigations include a possible process design, the process simulation using the software IPSEpro, a description of the operation characteristics, and a profitability analysis of the applied hydrogen production concept. The simulation result shows that 61 MW of hydrogen can be produced from 100 MW wood chips and 6 MW of electricity. As a result, hydrogen production costs of 54 EUR/MWh can be estimated. For the investigated concept, the wood chip price is the most important factor for the hydrogen production cost followed by investment costs for the plant and the realized plant operation time per year. (orig.)

  20. A Calorimetric Assay For Enzymatic Saccharification Of Biomass

    DEFF Research Database (Denmark)

    Murphy, Leigh; Borch, Kim; McFarland, K.C.

    2010-01-01

    A limited selection of assay and screening methodologies for cellulolytic enzymes has been stated as a restriction in biomass research. In this report we test the potential of isothermal calorimetry for this purpose. The primary observable in this technique (the heat flow in Watts), scales...... with the rate of hydrolysis, and unlike other approaches, it provides a continuous picture of the hydrolytic rate. It was found that the activity of a standard enzyme cocktail against purified cellulose substrates and dilute acid pretreated corn stover (PCS) was readily detected in calorimeters of different...... types, and that the calorimetric signal scaled with the enzyme activity measured by established analytical techniques. Hence, it was concluded that the heat flow provided a valid measure of the hydrolytic rate also in a complex biomass. The hydrolysis process was consistently found to be exothermic...

  1. Feasibility of Biomass Biodrying for Gasification Process

    Science.gov (United States)

    Hamidian, Arash

    An important challenge of biomass gasification is the limitation of feedstock quality especially the moisture content, which plays a significant role on the performance of gasification process. Gasification requires low moisture levels (20% and less) and several reports have emphasized on the moisture as a typical problem while gasifying biomass. Moisture affects overall reaction rates in the gasifiers as a result of temperature drop and ultimately increases tar content, decreases gas yield, changes the composition of produced gas and affects the efficiency. Therefore, it is mandatory to pre-treat the biomass before gasification and reduce the moisture content to the suitable and economic level. The well-known solutions are either natural drying (not practical for commercial plants) or conventional drying technologies (have high operating costs). Biodrying is an alternative process, which uses both convective air and heat of biological reactions as a source of energy, to reduce the moisture. In the biodrying reactor heat is generated from exothermic decomposition of organic fraction of biomass and that is why the process is called "self-heating process". Employing such technology for drying biomass at pre-treatment units of gasification process returns several economic and environmental advantages to mills. In Europe, municipal waste treatment (MSW) plants use the biodrying at commercial scale to degrade a part of the biodegradable fraction of waste to generate heat and reduce the moisture content for high quality SRF (Solid Recovered Fuel) production. In Italy, wine industry is seeking to develop biodrying for energy recovery of grape wastes after fermentation and distillation, which returns economic benefits to the industry. In Canada, the development of biodrying technology for pulp and paper industry was started at Ecole polytechnique de Montreal as an option for sludge management solution. Therefore, batch biodrying reactor was successfully developed in 2004

  2. Generation of hydrogen rich gas through fluidized bed gasification of biomass.

    Science.gov (United States)

    Karmakar, M K; Datta, A B

    2011-01-01

    The objective of this study was to investigate the process of generating hydrogen rich syngas through thermo chemical fluidized bed gasification of biomass. The experiments were performed in a laboratory scale externally heated biomass gasifier. Rice husk had been taken as a representative biomass and, steam had been used as the fluidizing and gasifying media. A thermodynamic equilibrium model was used to predict the gasification process. The work included the parametric study of process parameters such as reactor temperature and steam biomass ratio which generally influence the percentage of hydrogen content in the product gas. Steam had been used here to generate nitrogen free product gas and also to increase the hydrogen concentration in syngas with a medium range heating value of around 12 MJ/Nm3. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Spatial Structure of Above-Ground Biomass Limits Accuracy of Carbon Mapping in Rainforest but Large Scale Forest Inventories Can Help to Overcome.

    Directory of Open Access Journals (Sweden)

    Stéphane Guitet

    Full Text Available Precise mapping of above-ground biomass (AGB is a major challenge for the success of REDD+ processes in tropical rainforest. The usual mapping methods are based on two hypotheses: a large and long-ranged spatial autocorrelation and a strong environment influence at the regional scale. However, there are no studies of the spatial structure of AGB at the landscapes scale to support these assumptions. We studied spatial variation in AGB at various scales using two large forest inventories conducted in French Guiana. The dataset comprised 2507 plots (0.4 to 0.5 ha of undisturbed rainforest distributed over the whole region. After checking the uncertainties of estimates obtained from these data, we used half of the dataset to develop explicit predictive models including spatial and environmental effects and tested the accuracy of the resulting maps according to their resolution using the rest of the data. Forest inventories provided accurate AGB estimates at the plot scale, for a mean of 325 Mg.ha-1. They revealed high local variability combined with a weak autocorrelation up to distances of no more than10 km. Environmental variables accounted for a minor part of spatial variation. Accuracy of the best model including spatial effects was 90 Mg.ha-1 at plot scale but coarse graining up to 2-km resolution allowed mapping AGB with accuracy lower than 50 Mg.ha-1. Whatever the resolution, no agreement was found with available pan-tropical reference maps at all resolutions. We concluded that the combined weak autocorrelation and weak environmental effect limit AGB maps accuracy in rainforest, and that a trade-off has to be found between spatial resolution and effective accuracy until adequate "wall-to-wall" remote sensing signals provide reliable AGB predictions. Waiting for this, using large forest inventories with low sampling rate (<0.5% may be an efficient way to increase the global coverage of AGB maps with acceptable accuracy at kilometric resolution.

  4. Large Spatial Scale Variability in Bathyal Macrobenthos Abundance, Biomass, a- and b-Diversity along the Mediterranean Continental Margin

    NARCIS (Netherlands)

    Baldrighi, E.; Lavaleye, M.; Aliani, S.; Conversi, A.; Manini, E.

    2014-01-01

    The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can beseen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project (‘‘Biodiversity andEcosystem Functioning in Contrasting Southern European

  5. Characterization of second generation biomass under thermal conversion and the fate of nitrogen

    NARCIS (Netherlands)

    Giuntoli, J.

    2010-01-01

    This dissertation deals with the characterization of several biomass materials under thermal conversion conditions using small--scale equipment. The fuels are tested under the conditions of slow and fast heating rate pyrolysis and combustion, with the main goal of investigating the chemistry of

  6. Lab-Scale Investigations During Combustion of Agricultural Residues and Selected Polish Coals

    OpenAIRE

    Kordylewski Włodzimierz K.; Mościcki Krzysztof J.; Witkowski Karol J.

    2014-01-01

    Preliminary lab-scale investigations were conducted on slagging abatement in biomass-firing by fuel mixing. Three agriculture biomass fuels and olive cake were used in the experiments. Polish lignites and bituminous coals were examined as anti-sintering additives. The effects of chlorine release, potassium retention and ash sintering were examined by heating samples of biomass fuels and additives in the muffle oven and, next, firing them in the laboratory down-fired furnace at the temperature...

  7. ORC for electricity production in district heating plants. Experience of biomass fired boilers with electricity production based on ORC; ORC foer elproduktion i vaermeverk. Erfarenheter fraan biobraensleeldade pannor med ORC-baserad elproduktion

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Barbara

    2007-12-15

    The ORC (Organic Rankine Cycle) technology is an option for the production of electricity in heat production plants with steam boilers. Traditionally, the ORC technology has been used mainly in geothermal applications. However, during the last five years, it has become of interest also in bioenergy plants with electricity production in the 0,5-2 MW{sub e} range. Among others in Austria and Germany a number of plants have been installed during the first decade of the 2100th century. Today (2007), about 70 biomass based ORC plants are in operation in Europe. About 30 more plants are under installation and commissioning. In total, around 100 plants will be operating in the near future. In today's biomass fuelled ORC type CHP plants, the ORC circuit is driven by the energy in the flue gases from a biomass fuelled furnace. Via a thermal oil boiler, the energy is transferred to the ORC circuit. The ORC circuit is connected to the district heating net for cooling. Due to the fact that the ORC circuit is connected to 300 deg C flue gas, as compared to the 1990's waste water based ORC plants, an electrical yield of nearly 20% net is obtained in the ORC circuit. The overall electrical yield based on biomass is almost 16%. In the report, operational experience from a number of plants is reported. The economic advantage of the technology is discussed. In conclusion, the ORC technology is more economical than conventional steam turbine technology in the 0,5-2 MW{sub e} range. The calculated investment for a 2 MW{sub e} ORC based CHP plant is 40 kSEK/kW{sub e}, which is considerably lower than for a conventional steam turbine based CHP plant

  8. Northeast Regional Biomass Program

    Energy Technology Data Exchange (ETDEWEB)

    Lusk, P.D.

    1992-12-01

    The Northeast Regional Biomass Program has been in operation for a period of nine years. During this time, state managed programs and technical programs have been conducted covering a wide range of activities primarily aim at the use and applications of wood as a fuel. These activities include: assessments of available biomass resources; surveys to determine what industries, businesses, institutions, and utility companies use wood and wood waste for fuel; and workshops, seminars, and demonstrations to provide technical assistance. In the Northeast, an estimated 6.2 million tons of wood are used in the commercial and industrial sector, where 12.5 million cords are used for residential heating annually. Of this useage, 1504.7 mw of power has been generated from biomass. The use of wood energy products has had substantial employment and income benefits in the region. Although wood and woodwaste have received primary emphasis in the regional program, the use of municipal solid waste has received increased emphasis as an energy source. The energy contribution of biomass will increase as potentia users become more familiar with existing feedstocks, technologies, and applications. The Northeast Regional Biomass Program is designed to support region-specific to overcome near-term barriers to biomass energy use.

  9. Heat flows in a full scale room exposed to natural climate

    Energy Technology Data Exchange (ETDEWEB)

    Wallenten, P.

    1998-09-01

    It is, with the thermal models used in today`s building simulation programs, possible to calculate the major part of the heat transfer in a room with an ambient outer wall. However, there are some parameters these models calculate with less or unknown accuracy: heat flows in poorly insulated walls or windows, heat flows in a room exposed to strong solar radiation, temperatures on the inside of ambient outer walls and windows. The reason for these difficulties is mainly that there is a lack of experimental data for the detailed energy transfer in a window exposed to ambient climate and the convective energy transport in a room exposed to ambient climate. The aim of this study was to investigate the detailed energy transfer at an ambient wall including window. The investigation included both theoretic analysis and measurements performed under conditions close to the real situation with ambient climate. The method used in this study was to estimate the heat flow through wall and window from measured solar radiation on the facade and temperatures. The temperatures were measured inside the wall, on the window panes, in the air, at inner surfaces etc. The longwave radiation was calculated from surface temperatures. The convective heat transfer was calculated as the difference between the heat flow through the building element and the longwave radiation. This indirect way of measuring the convective heat transfer was not as accurate as other more direct techniques but it was however a method which permitted measurement under realistic conditions 27 refs, 90 figs, 7 tabs

  10. Biomass recalcitrance

    DEFF Research Database (Denmark)

    Felby, Claus

    2009-01-01

    Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes - this co......Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes...... - this collective resistance is known as "biomass recalcitrance." Breakthrough technologies are needed to overcome barriers to developing cost-effective processes for converting biomass to fuels and chemicals. This book examines the connection between biomass structure, ultrastructure, and composition......, to resistance to enzymatic deconstruction, with the aim of discovering new cost-effective technologies for biorefineries. It contains chapters on topics extending from the highest levels of biorefinery design and biomass life-cycle analysis, to detailed aspects of plant cell wall structure, chemical treatments...

  11. Finding the chemistry in biomass pyrolysis: Millisecond chemical kinetics and visualization

    Science.gov (United States)

    Krumm, Christoph

    Biomass pyrolysis is a promising thermochemical method for producing fuels and chemicals from renewable sources. Development of a fundamental understanding of biomass pyrolysis chemistry is difficult due to the multi-scale and multi-phase nature of the process; biomass length scales span 11 orders of magnitude and pyrolysis phenomena include solid, liquid, and gas phase chemistry in addition to heat and mass transfer. These complexities have a significant effect on chemical product distributions and lead to variability between reactor technologies. A major challenge in the study of biomass pyrolysis is the development of kinetic models capable of describing hundreds of millisecond-scale reactions of biomass into lower molecular weight products. In this work, a novel technique for studying biomass pyrolysis provides the first- ever experimental determination of kinetics and rates of formation of the primary products from cellulose pyrolysis, providing insight into the millisecond-scale chemical reaction mechanisms. These findings highlight the importance of heat and mass transport limitations for cellulose pyrolysis chemistry and are used to identify the length scales at which transport limitations become relevant during pyrolysis. Through this technique, a transition is identified, known as the reactive melting point, between low and high temperature depolymerization. The transition between two mechanisms of cellulose decompositions unifies the mechanisms that govern low temperature char formation, intermediate pyrolysis conditions, and high temperature gas formation. The conditions under which biomass undergoes pyrolysis, including modes of heat transfer, have been shown to significantly affect the distribution of biorenewable chemical and fuel products. High-speed photography is used to observe the liftoff of initially crystalline cellulose particles when impinged on a heated surface, known as the Leidenfrost effect for room-temperature liquids. Order

  12. The Impact of Trends in the Large Scale Atmospheric Circulation on Mediterranean Surface Turbulent Heat Fluxes

    Science.gov (United States)

    Romanski, Joy; Hameed, Sultan

    2015-01-01

    Interannual variations of latent heat fluxes (LHF) and sensible heat fluxes (SHF) over the Mediterranean for the boreal winter season (DJF) show positive trends during 1958-2011. Comparison of correlations between the heat fluxes and the intensity and location of the Azores High (AH), and the NAO and East Atlantic-West Russia (EAWR) teleconnections, along with analysis of composites of surface temperature, humidity and wind fields for different teleconnection states, demonstrates that variations of the AH are found to explain the heat flux changes more successfully than the NAO and the EAWR. Trends in sea level pressure and longitude of the Azores High during DJF show a strengthening, and an eastward shift. DJF Azores High pressure and longitude are shown to co-vary such that variability of the Azores High occurs along an axis defined by lower pressure and westward location at one extreme, and higher pressure and eastward location at the other extreme. The shift of the Azores High from predominance of the low/west state to the high/east state induces trends in Mediterranean Sea surface winds, temperature and moisture. These, combined with sea surface warming trends, produce trends in wintertime Mediterranean Sea sensible and latent heat fluxes.

  13. Gas and heat dynamics of a micro-scaled atmospheric pressure plasma reference jet

    Science.gov (United States)

    Kelly, Seán; Golda, Judith; Turner, Miles M.; Schulz-von der Gathen, Volker

    2015-11-01

    Gas and heat dynamics of the ‘Cooperation on Science and Technology (COST) Reference Microplasma Jet’ (COST-jet), a European lead reference device for low temperature atmospheric pressure plasma application, are investigated. Of particular interest to many biomedical application scenarios, the temperature characteristics of a surface impacted by the jet are revealed. Schlieren imaging, thermocouple measurements, infrared thermal imaging and numerical modelling are employed. Temperature spatial profiles in the gas domain reveal heating primarily of the helium fraction of the gas mixture. Thermocouple and model temporal data show a bounded exponential temperature growth described by a single characteristic time parameter to reach  ∼63% or (1-1/e) fraction of the temperature increase. Peak temperatures occurred in the gas domain where the carrier jet exits the COST-jet, with values ranging from ambient temperatures to in excess of 100 °C in ‘α-mode’ operation. In a horizontal orientation of the COST-jet a curved trajectory of the helium effluent at low gas flows results from buoyant forces. Gas mixture profiles reveal significant containment of the helium concentrations for a surface placed in close proximity to the COST-jet. Surface heating of a quartz plate follows a similar bounded exponential temporal temperature growth as device heating. Spatial profiles of surface heating are found to correlate strongly to the impacting effluent where peak temperatures occur in regions of maximum surface helium concentration.

  14. Marine biomass power plant using methane fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, T.; Saito, H.; Amano, T.; Sugawara, H.; Seki, T.; Abe, T. [Technology Research Inst., Tokyo Gas Co. Ltd., Tokyo (Japan)

    2004-07-01

    This study presented an effective way to produce biogas from the large quantities of seaweed waste in Japan. A large-scale marine biomass pilot plant was built to produce biogas from marine biomass. Methane fermentation was the process used to produce biogas from Laminaria sp. The maximum treating capacity of the pilot plant is 1 ton of seaweed per day. The pilot plant includes a pretreatment facility, fermentation, biogas storage and power generation. The maximum methane yield from the biomass plant is 22 cubic ton-seaweed. The purified biogas has generated 10 kW of electricity and 23 kW of heat. The biogas was also mixed with natural gas for use in a gas engine generator. The engine operation remained stable despite changes in quantity and composition of the collected biogas caused by changes with the source of biomass and sea conditions. The thermal efficiency of the gas engine running on mixed biogas and natural gas was more than 10 per cent higher than an engine running on biogas fuel alone. 4 refs., 2 tabs., 3 figs.

  15. Energetic potential of algal biomass from high-rate algal ponds for the production of solid biofuels.

    Science.gov (United States)

    Costa, Taynan de Oliveira; Calijuri, Maria Lúcia; Avelar, Nayara Vilela; Carneiro, Angélica de Cássia de Oliveira; de Assis, Letícia Rodrigues

    2017-08-01

    In this investigation, chemical characteristics, higher, lower and net heating value, bulk and energy density, and thermogravimetric analysis were applied to study the thermal characteristics of three algal biomasses. These biomasses, grown as by-products of wastewater treatment in high-rate algal ponds (HRAPs), were: (i) biomass produced in domestic effluent and collected directly from an HRAP (PO); (ii) biomass produced in domestic effluent in a mixed pond-panel system and collected from the panels (PA); and (iii) biomass originating from the treatment effluent from the meat processing industry and collected directly from an HRAP (IN). The biomass IN was the best alternative for thermal power generation. Subsequently, a mixture of the algal biomasses and Jatropha epicarp was used to produce briquettes containing 0%, 25%, 50%, 75%, and 100% of algal biomass, and their properties were evaluated. In general, the addition of algal biomass to briquettes decreased both the hygroscopicity and fixed carbon content and increased the bulk density, ash content, and energy density. A 50% proportion of biomass IN was found to be the best raw material for producing briquettes. Therefore, the production of briquettes consisting of algal biomass and Jatropha epicarp at a laboratory scale was shown to be technically feasible.

  16. International seminar on biomass and fossil fuels co-firing in power plants and heating plants in Europe; Seminaire international sur la cocombustion de biomasse et d'energies fossiles dans les centrales electriques et les chaufferies en Europe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The aim of the European commission which has fixed to 12% the share of renewable energies in the total energy consumption up to 2010, is to develop the biomass sector. Co-firing is a solution that allows to increase significantly the use of biomass because it does not require important investments. Today, about 150 power plants in Europe use co-firing. An Altener project named 'Cofiring' has ben settled in order to bring together and analyze the European experience in this domain and to sustain and rationalize the design of future projects. The conclusions of this study, coordinated by VTT Energy and which involves CARMEN (Germany), CBE (Portugal), the Danish centre for landscape and planning, ITEBE (France), KOBA (Italy), SLU (Sweden), and EVA (Austria), were presented during this international seminar. (J.S.)

  17. Mercury emissions during cofiring of sub-bituminous coal and biomass (chicken waste, wood, coffee residue, and tobacco stalk) in a laboratory-scale fluidized bed combustor.

    Science.gov (United States)

    Cao, Yan; Zhou, Hongcang; Fan, Junjie; Zhao, Houyin; Zhou, Tuo; Hack, Pauline; Chan, Chia-Chun; Liou, Jian-Chang; Pan, Wei-Ping

    2008-12-15

    Four types of biomass (chicken waste, wood pellets, coffee residue, and tobacco stalks) were cofired at 30 wt % with a U.S. sub-bituminous coal (Powder River Basin Coal) in a laboratory-scale fluidized bed combustor. A cyclone, followed by a quartz filter, was used for fly ash removal during tests. The temperatures of the cyclone and filter were controlled at 250 and 150 degrees C, respectively. Mercury speciation and emissions during cofiring were investigated using a semicontinuous mercury monitor, which was certified using ASTM standard Ontario Hydra Method. Test results indicated mercury emissions were strongly correlative to the gaseous chlorine concentrations, but not necessarily correlative to the chlorine contents in cofiring fuels. Mercury emissions could be reduced by 35% during firing of sub-bituminous coal using only a quartz filter. Cofiring high-chlorine fuel, such as chicken waste (Cl = 22340 wppm), could largely reduce mercury emissions by over 80%. When low-chlorine biomass, such as wood pellets (Cl = 132 wppm) and coffee residue (Cl = 134 wppm), is cofired, mercury emissions could only be reduced by about 50%. Cofiring tobacco stalks with higher chlorine content (Cl = 4237 wppm) did not significantly reduce mercury emissions. This was also true when limestone was added while cofiring coal and chicken waste because the gaseous chlorine was reduced in the freeboard of the fluidized bed combustor, where the temperature was generally below 650 degrees C without addition of the secondary air. Gaseous speciated mercury in flue gas after a quartz filter indicated the occurrence of about 50% of total gaseous mercury to be the elemental mercury for cofiring chicken waste, but occurrence of above 90% of the elemental mercury for all other cases. Both the higher content of alkali metal oxides or alkali earth metal oxides in tested biomass and the occurrence of temperatures lower than 650 degrees C in the upper part of the fluidized bed combustor seemed to be

  18. Large scale three-dimensional topology optimisation of heat sinks cooled by natural convection

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Sigmund, Ole; Aage, Niels

    2016-01-01

    This work presents the application of density-based topology optimisation to the design of three-dimensional heat sinks cooled by natural convection. The governing equations are the steady-state incompressible Navier-Stokes equations coupled to the thermal convection-diffusion equation through...... topologies verify prior conclusions regarding fin length/thickness ratios and Biot numbers, but also indicate that carefully tailored and complex geometries may improve cooling behaviour considerably compared to simple heat fin geometries. (C) 2016 Elsevier Ltd. All rights reserved....

  19. Prediction of mean skin temperature for use as a heat strain scale by introducing an equation for sweating efficiency

    Science.gov (United States)

    Kubota, H.; Kuwabara, K.; Hamada, Y.

    2014-09-01

    The present paper made the heat balance equation (HBE) for nude or minimally clad subjects a linear function of mean skin temperature ( t sk) by applying new equations for sweating efficiency ( η sw) and thermoregulatory sweat rate ( S wR). As the solution of the HBE, the equation predicting t sk was derived and used for a heat strain scale of subjects. The η sw was proportional to the reciprocal of S w/ E max ( S w, sweat rate; E max maximum evaporative capacity) and the S wR was proportional to t sk with a parameter of the sweating capacity of the subject. The errors of predicted t sk from observations due to the approximation of η sw were examined based on experimental data conducted on eight young male subjects. The value of errors of t sk was -0.10 ± 0.42 °C (mean ± sample standard deviation (SSD)). We aim to apply the predicted t sk of a subject at a level of sweating capacity as a heat strain scale of a function of four environmental factors (dry- and wet-bulb temperatures, radiation, and air velocity) and three human factors (metabolic rate, sweating capacity, and clothing (≤0.2clo)).

  20. Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales

    Science.gov (United States)

    Zampieri, M.; Ceglar, A.; Dentener, F.; Toreti, A.

    2017-06-01

    Heat waves and drought are often considered the most damaging climatic stressors for wheat. In this study, we characterize and attribute the effects of these climate extremes on wheat yield anomalies (at global and national scales) from 1980 to 2010. Using a combination of up-to-date heat wave and drought indexes (the latter capturing both excessively dry and wet conditions), we have developed a composite indicator that is able to capture the spatio-temporal characteristics of the underlying physical processes in the different agro-climatic regions of the world. At the global level, our diagnostic explains a significant portion (more than 40%) of the inter-annual production variability. By quantifying the contribution of national yield anomalies to global fluctuations, we have found that just two concurrent yield anomalies affecting the larger producers of the world could be responsible for more than half of the global annual fluctuations. The relative importance of heat stress and drought in determining the yield anomalies depends on the region. Moreover, in contrast to common perception, water excess affects wheat production more than drought in several countries. We have also performed the same analysis at the subnational level for France, which is the largest wheat producer of the European Union, and home to a range of climatic zones. Large subnational variability of inter-annual wheat yield is mostly captured by the heat and water stress indicators, consistently with the country-level result.

  1. Cost of electricity from small scale co-generation of electricity and heat

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, Bjoern

    2012-07-15

    There is an increasing interest in Sweden for using also small heat loads for cogeneration of electricity and heat. Increased use of small CHP-plants with heat supply capacities from a few 100 kW(h) up to 10 MW(h) cannot change the structure of the electricity supply system significantly, but could give an important contribution of 2 - 6 TWh(e) annually. The objective of this study was to clarify under what conditions electricity can be generated in small wood fired CHP-plants in Sweden at costs that can compete with those for plants using fossil fuels or nuclear energy. The capacity range studied was 2 - 10 MW(h). The results should facilitate decisions about the meaningfulness of considering CHP as an option when new heat supply systems for small communities or sawmills are planned. At the price for green certificates in Sweden, 250 - 300 SEK/MWh(e), generation costs in small wood fired CHP-plants should be below about 775 SEK/MWh(e) to compete with new nuclear power plants and below about 925 SEK/MWh(e) to compete with generation using fossil fuels.

  2. Industrial-scale heat pump in a waste incinerator; Grosswaermepumpe in einer Muellverbrennungsanlage

    Energy Technology Data Exchange (ETDEWEB)

    Bailer, P. [Sulzer Friotherm, Winterthur (Switzerland)

    2000-12-01

    Umea Energi AG at Umea in northern Sweden constructed an incinerator of 20 t/h. The plant was designed for maximum ecological acceptability and is probably the world's most economical incinerator. Incineration is combined with heat and power generation in two Sulzer Friotherm UNITOP28 heat pumps with a total capacity of about 14 MW{sub th} at a water temperature of 75 C and with R134a as refrigerant. The wet flue gas leaving the scrubber is condensed and serves as heat source. Heat recovery enhances the total efficiency of the plant from 94% to 107% - quite a perpetuum mobile?. [German] Umea Energi AG in Umea Nordschweden hat eine neue Muellverbrennungsanlage fuer eine Muellmenge von 20 t/h gebaut. Die Muellverbrennung erfuellt strengste Umweltanforderungen und ist vermutlich die wirtschaftlichste Muellverbrennungsanlage der Welt. Die Verbrennung wird kombiniert mit der Erzeugung von Strom- und Heiz-Energie. Als wichtiger Teil in dieser Anlage ist der Einsatz von zwei Sulzer Friotherm Grosswaermepumpen UNITOP28 mit einer gesamten Heizleistung von ca. 14 MW bei einer Heizwassertemperatur von 75 C mit R134a als Kaeltemittel. Das durch die Rauchgaswaesche feuchte Rauchgas wird kondensiert und dient als Waermequelle. Die Waermerueckgewinnung durch die Waermepumpen erhoeht den Gesamtwirkungsgrad der Anlage von 94% auf 107% - somit ein Perpetuum mobile?. (orig.)

  3. Glenn-ht/bem Conjugate Heat Transfer Solver for Large-scale Turbomachinery Models

    Science.gov (United States)

    Divo, E.; Steinthorsson, E.; Rodriquez, F.; Kassab, A. J.; Kapat, J. S.; Heidmann, James D. (Technical Monitor)

    2003-01-01

    A coupled Boundary Element/Finite Volume Method temperature-forward/flux-hack algorithm is developed for conjugate heat transfer (CHT) applications. A loosely coupled strategy is adopted with each field solution providing boundary conditions for the other in an iteration seeking continuity of temperature and heat flux at the fluid-solid interface. The NASA Glenn Navier-Stokes code Glenn-HT is coupled to a 3-D BEM steady state heat conduction code developed at the University of Central Florida. Results from CHT simulation of a 3-D film-cooled blade section are presented and compared with those computed by a two-temperature approach. Also presented are current developments of an iterative domain decomposition strategy accommodating large numbers of unknowns in the BEM. The blade is artificially sub-sectioned in the span-wise direction, 3-D BEM solutions are obtained in the subdomains, and interface temperatures are averaged symmetrically when the flux is updated while the fluxes are averaged anti-symmetrically to maintain continuity of heat flux when the temperatures are updated. An initial guess for interface temperatures uses a physically-based 1-D conduction argument to provide an effective starting point and significantly reduce iteration. 2-D and 3-D results show the process converges efficiently and offers substantial computational and storage savings. Future developments include a parallel multi-grid implementation of the approach under MPI for computation on PC clusters.

  4. Models of SOL transport and their relation to scaling of the divertor heat flux width in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Makowski, M.A., E-mail: makowski1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lasnier, C.J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Leonard, A.W.; Osborne, T.H. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Umansky, M. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Elder, J.D. [University of Toronto Institute for Aerospace Studies, Toronto M3H 5T6 (Canada); Nichols, J.H. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Stangeby, P.C. [University of Toronto Institute for Aerospace Studies, Toronto M3H 5T6 (Canada); Baver, D.A.; Myra, J.R. [Lodestar Research Corporation, Boulder, CO (United States)

    2015-08-15

    Strong support for the critical pressure gradient model for the heat flux width has been obtained, in that the measured separatrix pressure gradient lies below and scales similarly to the pressure gradient limit obtained from the ideal, infinite-n stability codes, BALOO and 2DX, in all cases that have been examined. Predictions of a heuristic drift model for the heat flux width are also in qualitative agreement with the measurements. These results have been obtained using an improved high rep-rate and higher edge spatial resolution Thomson scattering system on DIII-D to measure the upstream electron temperature and density profiles. In order to compare theory and experiment, profiles of density, temperature, and pressure for both electrons and ions are needed as well values of these quantities at the separatrix. A simple method to identify a proxy for the separatrix has been developed to do so.

  5. Slagging and fouling in biomass co-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ana Abel Tortosa-Masia; Falk Ahnert; Harmut Spliethoff; Jean Claude Loux; Klaus R. G. Hein [Technical University of Delft, Delft (Netherlands). Energy Technology

    2005-07-01

    Deposit formation on heat transfer surfaces, namely slagging and fouling, is one of the main problems associated with biomass combustion. Reducing deposits formation can optimise plant operation. Literature review and experience show a clear research demand towards methods for on-line detection of deposits in large-scale boilers. A system consisting of a monitoring model and an on-line measurement method is presented. Results of testing show the appropriateness of the model to visualise deposit tendencies, and the possibility of determining the influence of ash deposits on heat transfer using the measurement method. 41 refs., 7 figs., 1 tab.

  6. Biomass and biomass change in lodgepole pine stands in Alberta

    Science.gov (United States)

    Robert A. Monserud; Shongming Huang; Yuqing Yang

    2006-01-01

    We describe methods and results for broad-scale estimation and mapping of forest biomass for the Canadian province of Alberta. Differences over successive decades provided an estimate of biomass change. Over 1500 permanent sample plots (PSP) were analyzed from across the range of lodgepole pine (Pinus contorta var. latifolia Engelm...

  7. Material problems related to large scale firing of biomass. Steam oxidation of TP 347H FG and X20

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2009-07-01

    TP 347 H and X20 is often used as construction material in biomass-fired boilers. The corrosion rate of the alloys is affected by the metal temperature. In this project, the oxidation behaviour of TP 347H FG and X20 is studied by field-testing, laboratory exposures, and thermodynamic/kinetic modelling. The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in 4 test superheater loops in a coal-fired power plant. The steel was exposed for 7720, 22985, 29588, and 57554 h at metal temperatures between 499 and 650 deg. C. In the laboratory furnace, the oxidation behaviour of TP 347H FG, TP 347H CG, and X20 was studied in water vapour containing environments (8 or 46%) in the temperature range 500-700 deg. C. Air, Ar and Ar+7% H{sub 2} were used as carrier gas. The microstructure of the oxide layer and the subjacent alloy was investigated with X-ray diffraction (XRD), reflective light microscopy (RLM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) equipped with electron diffraction (ED) and EDS. Double-layered oxides developed during steam oxidation of TP 347H FG both during field-testing and during laboratory exposures. TEM investigation suggested that the interior of the alloy grain was oxidised internally, forming particles of metallic Ni/Fe and Fe-Cr spinel. A FeCr{sub 2}O{sub 4} layer developed along the former alloy grain boundaries. Cr{sub 2}O{sub 3} developed in between this layer and the alloy during field-testing, and its formation was promoted by higher temperature. The morphology of the inner layer for the samples oxidised below and above approx. 585 deg. C looked very different in SEM (field-testing). It is suggested that more Cr is incorporated into the oxide layer at higher temperature, gradually transforming the morphology of the inner oxide layer. The alloy beneath the oxide layer was depleted in Cr

  8. The Effect of Electron Cyclotron Heating on Multi-Scale Fluctuations in ITER Baseline Scenario Discharges on DIII-D

    Science.gov (United States)

    Maronini, A.; Rost, J. C.; Porkolab, M.; Davis, E. M.; Pinsker, R. I.; Burrell, K. H.; Staebler, G. M.; Grierson, B. A.

    2016-10-01

    Experiments on DIII-D simulating the ITER Baseline Scenario show that torque-free pure electron heating (ECH) modifies profiles and affects density fluctuations at electron and at ion scales in different ways. The Phase Contrast Imaging diagnostic is used to measure the time evolution of density fluctuations going from mixed beam/ECH to pure beam heating at fixed βN. The intensity of fluctuations at scales between 2 and 5 cm-1 increases promptly after turning off ECH; at larger scales, in contrast, it decreases only after other equilibrium quantities have evolved to a new stationary state. Non-linear gyro-kinetic simulations suggest that the former response is due to ETG modes that also generate a prompt inward particle pinch; the latter is consistent with the dominant ITG modes being weakened by the increased flow shear in the new state. Such fluctuations in ITER might affect fusion performance via modifications to steady-state profiles. Work supported by the US Department of Energy under DE-FG02-94ER54235 and DE-FC02-04ER54698.

  9. Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiao, E-mail: liuxiao07@mails.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Wang Wei; Shi Yunchun; Zheng Lei [School of Environment, Tsinghua University, Beijing 100084 (China); Gao Xingbao [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Qiao Wei [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhou Yingjun [Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540 (Japan)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. Black-Right-Pointing-Pointer System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m{sup 3} d){sup -1} were analyzed. Black-Right-Pointing-Pointer A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and HRT of 15d. Black-Right-Pointing-Pointer With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. Black-Right-Pointing-Pointer The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2-8.0 kg volatile solid (VS) (m{sup 3} d){sup -1}, with VS reduction rates of 61.7-69.9%, and volumetric biogas production of 0.89-5.28 m{sup 3} (m{sup 3} d){sup -1}. A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m{sup 3} d){sup -1}. This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

  10. Development of a hot heat exchanger and a cleaning system for a 35 kW hermetic four cylinder Stirling engine for solid biomass fuels

    DEFF Research Database (Denmark)

    Carlsen, Henrik; Marinitsch, Gerald; Schöch, Martin

    2005-01-01

    been operated for more than 9,000 hours. Operating experiences gained from these plants formed the basis for the further development of this technology. The experiences showed that the efficiency of the Stirling hot gas heat exchanger and of the hot gas heat exchanger cleaning system have to be further...... optimised. Within the scope of a RD&D project, a new hot gas heat exchanger and a new cleaning system have been developed and optimised in cooperation of the AUSTRIAN BIOENERGY CENTRE GmbH, the Technical University of Denmark, MAWERA Holzfeuerungsanlagen GmbH, Austria, and BIOS BIOENERGIESYSTEME Gmb......H, Austria. The new design of the Stirling hot gas heat exchanger has been developed in order to optimise the performance of the engine and simplify the geometry. In this respect, an equal distribution of the heat transfer across each tube in the hot gas heat exchanger, the reduction of the internal Helium...

  11. Feasibility of Storing Latent Heat with Liquid Crystals. Proof of Concept at Lab Scale

    Directory of Open Access Journals (Sweden)

    Rocío Bayón

    2016-04-01

    Full Text Available In this work, the first experimental results of thermotropic liquid crystals used as phase change materials for thermal storage are presented. For that purpose, the n = 10 derivative from the family of 4′-n-alkoxybiphenyl-4-carboxylic acids has been prepared. Different techniques like polarized-light microscopy, differential scanning calorimetry, thermogravimetric analysis and rheological measurements have been applied for its characterization. Having a mesophase/isotropic transition temperature around 251 °C, a clearing enthalpy of 55 kJ/kg, a thermal heat capacity of around 2.4 kJ/kg and a dynamic viscosity lower than 0.6 Pas, this compound fulfills the main requirements for being considered as latent heat storage material. Although further studies on thermal stability are necessary, the results already obtained are both promising and encouraging since they demonstrate de viability of this new application of liquid crystals as thermal storage media.

  12. Results of IEA SHC Task 45: Large Scale Solar Heating and Cooling Systems. Subtask A: “Collectors and Collector Loop”

    DEFF Research Database (Denmark)

    Bava, Federico; Nielsen, Jan Erik; Knabl, Samuel

    2016-01-01

    The IEA SHC Task 45 Large Scale Solar Heating and Cooling Systems, carried out between January 2011 and December 2014, had the main objective to assist in the development of a strong and sustainable market of large solar heating systems by focusing on high performance and reliability of systems. ...

  13. Regional CO2 and latent heat surface fluxes in the Southern Great Plains: Measurements, modeling, and scaling

    Energy Technology Data Exchange (ETDEWEB)

    Riley, W. J.; Biraud, S.C.; Torn, M.S.; Fischer, M.L.; Billesbach, D.P.; Berry, J.A.

    2009-08-15

    Characterizing net ecosystem exchanges (NEE) of CO{sub 2} and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface model of trace gas and energy exchanges (isotope-enabled land surface model (ISOLSM)). Yearly variations in vegetation cover distributions were estimated from Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index and compared to regional and subregional vegetation cover type estimates from the U.S. Department of Agriculture census. We first applied ISOLSM at a 250 m spatial scale to account for vegetation cover type and leaf area variations that occur on hundred meter scales. Because of computational constraints, we developed a subsampling scheme within 10 km 'macrocells' to perform these high-resolution simulations. We estimate that the Atmospheric Radiation Measurement Climate Research Facility SGP region net CO{sub 2} exchange with the local atmosphere was -240, -340, and -270 gC m{sup -2} yr{sup -1} (positive toward the atmosphere) in 2003, 2004, and 2005, respectively, with large seasonal variations. We also performed simulations using two scaling approaches at resolutions of 10, 30, 60, and 90 km. The scaling approach applied in current land surface models led to regional NEE biases of up to 50 and 20% in weekly and annual estimates, respectively. An important factor in causing these biases was the complex leaf area index (LAI) distribution

  14. Biomass thermochemical gasification: Experimental studies and modeling

    Science.gov (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  15. Nanoscale modifications in the early heating stages of bone are heterogeneous at the microstructural scale.

    Science.gov (United States)

    Gourrier, Aurélien; Chadefaux, Céline; Lemaitre, Estelle; Bellot-Gurlet, Ludovic; Reynolds, Michael; Burghammer, Manfred; Plazanet, Marie; Boivin, Georges; Farlay, Delphine; Bunk, Oliver; Reiche, Ina

    2017-01-01

    Nanoscale studies of bone provide key indicators to evidence subtle structural changes that may occur in the biomedical, forensic and archaeological contexts. One specific problem encountered in all those disciplines, for which the identification of nanostructural cues could prove useful, is to properly monitor the effect of heating on bone tissue. In particular, the mechanisms at work at the onset of heating are still relatively unclear. Using a multiscale approach combining Raman microspectroscopy, transmission electron microscopy (TEM), synchrotron quantitative scanning small-angle X-ray scattering imaging (qsSAXSI) and