INCREASING WATERFLOOD RESERVES IN THE WILMINGTON OIL FIELD THROUGH IMPROVED RESERVOIR CHARACTERIZATION AND RESERVOIR MANAGEMENT

Energy Technology Data Exchange (ETDEWEB)

Scott Walker; Chris Phillips; Roy Koerner; Don Clarke; Dan Moos; Kwasi Tagbor

2002-02-28

This project increased recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs. Transferring technology so that it can be applied in other sections of the Wilmington Field and by operators in other slope and basin reservoirs is a primary component of the project. This project used advanced reservoir characterization tools, including the pulsed acoustic cased-hole logging tool, geologic three-dimensional (3-D) modeling software, and commercially available reservoir management software to identify sands with remaining high oil saturation following waterflood. Production from the identified high oil saturated sands was stimulated by recompleting existing production and injection wells in these sands using conventional means as well as a short radius redrill candidate. Although these reservoirs have been waterflooded over 40 years, researchers have found areas of remaining oil saturation. Areas such as the top sand in the Upper Terminal Zone Fault Block V, the western fault slivers of Upper Terminal Zone Fault Block V, the bottom sands of the Tar Zone Fault Block V, and the eastern edge of Fault Block IV in both the Upper Terminal and Lower Terminal Zones all show significant remaining oil saturation. Each area of interest was uncovered emphasizing a different type of reservoir characterization technique or practice. This was not the original strategy but was necessitated by the different levels of progress in each of the project activities.

Waterflood using a muskeg water source Milligan Creek Unit, B. C

Energy Technology Data Exchange (ETDEWEB)

Cracknell, W C

1968-01-01

The Milligan Creek field, in NE. British Columbia, is a small but high capacity sand reservoir of Triassic age. Waterflooding was initiated early in the life of the reservoir to provide pressure maintenance and increase oil recovery from the pool. Due to the lack of a subsurface supply in the area, muskeg water from a nearby creek was utilized. This cold water with its high content or iron and organic material has proven to be a major water treatment problem. After considerable experimentation a process using flocculation, filtration through a sand- anthracite filter, and deaeration was found to yield water satisfactory for injection. Seasonal variation in water quality remains a problem. Four years of waterflooding have yielded satisfactory results with a decrease in voidage, an increase in reservoir pressure and the attainment of a high level of production for a pool of this size. Performance has been accurately predicted by means of a potentiometric model.

DESIGN AND IMPLEMENTATION OF A CO2 FLOOD UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL INJECTION WELLS IN A SHALLOW SHELF CARBONATE APPROACHING WATERFLOOD DEPLETION

Energy Technology Data Exchange (ETDEWEB)

K.J. Harpole; Ed G. Durrett; Susan Snow; J.S. Bles; Carlon Robertson; C.D. Caldwell; D.J. Harms; R.L. King; B.A. Baldwin; D. Wegener; M. Navarrette

2002-09-01

The purpose of this project was to economically design an optimum carbon dioxide (CO{sub 2}) flood for a mature waterflood nearing its economic abandonment. The original project utilized advanced reservoir characterization and CO{sub 2} horizontal injection wells as the primary methods to redevelop the South Cowden Unit (SCU). The development plans; project implementation and reservoir management techniques were to be transferred to the public domain to assist in preventing premature abandonment of similar fields. The Unit was a mature waterflood with water cut exceeding 95%. Oil must be mobilized through the use of a miscible or near-miscible fluid to recover significant additional reserves. Also, because the unit was relatively small, it did not have the benefit of economies of scale inherent in normal larger scale projects. Thus, new and innovative methods were required to reduce investment and operating costs. Two primary methods used to accomplish improved economics were use of reservoir characterization to restrict the flood to the higher quality rock in the unit and use of horizontal injection wells to cut investment and operating costs. The project consisted of two budget phases. Budget Phase I started in June 1994 and ended late June 1996. In this phase Reservoir Analysis, Characterization Tasks and Advanced Technology Definition Tasks were completed. Completion enabled the project to be designed, evaluated, and an Authority for Expenditure (AFE) for project implementation submitted to working interest owners for approval. Budget Phase II consisted of the implementation and execution of the project in the field. Phase II was completed in July 2001. Performance monitoring, during Phase II, by mid 1998 identified the majority of producing wells which under performed their anticipated withdrawal rates. Newly drilled and re-activated wells had lower offtake rates than originally forecasted. As a result of poor offtake, higher reservoir pressure was a concern

Assessment of potential increased oil production by polymer-waterflood in northern and southern mid-continent oil fields. Progress report for the quarter ending December 31, 1978

Energy Technology Data Exchange (ETDEWEB)

None

1978-01-01

Six tasks are reported on: geological and engineering study of the DOE-Kewanee polymer-augmented waterflood, review of polymer injection program in this field, evaluation of results of polymer-augmented waterflood in this field, review of geological and engineering characteristics of oil fields now in waterflood as candidates for polymer augmentation, review of fields currently under primary production, and determination of ranges of future increased oil production from the polymer-water process in the project area.

Using laboratory flow experiments and reactive chemical transport modeling for designing waterflooding of the Agua Fria Reservoir, Poza Rica-Altamira Field, Mexico

Energy Technology Data Exchange (ETDEWEB)

Birkle, P.; Pruess, K.; Xu, T.; Figueroa, R.A. Hernandez; Lopez, M. Diaz; Lopez, E. Contreras

2008-10-01

Waterflooding for enhanced oil recovery requires that injected waters must be chemically compatible with connate reservoir waters, in order to avoid mineral dissolution-and-precipitation cycles that could seriously degrade formation permeability and injectivity. Formation plugging is a concern especially in reservoirs with a large content of carbonates, such as calcite and dolomite, as such minerals typically react rapidly with an aqueous phase, and have strongly temperature-dependent solubility. Clay swelling can also pose problems. During a preliminary waterflooding pilot project, the Poza Rica-Altamira oil field, bordering the Gulf coast in the eastern part of Mexico, experienced injectivity loss after five months of reinjection of formation waters into well AF-847 in 1999. Acidizing with HCl restored injectivity. We report on laboratory experiments and reactive chemistry modeling studies that were undertaken in preparation for long-term waterflooding at Agua Frma. Using analogous core plugs obtained from the same reservoir interval, laboratory coreflood experiments were conducted to examine sensitivity of mineral dissolution and precipitation effects to water composition. Native reservoir water, chemically altered waters, and distilled water were used, and temporal changes in core permeability, mineral abundances and aqueous concentrations of solutes were monitored. The experiments were simulated with the multi-phase, nonisothermal reactive transport code TOUGHREACT, and reasonable to good agreement was obtained for changes in solute concentrations. Clay swelling caused an additional impact on permeability behavior during coreflood experiments, whereas the modeled permeability depends exclusively on chemical processes. TOUGHREACT was then used for reservoir-scale simulation of injecting ambient-temperature water (30 C, 86 F) into a reservoir with initial temperature of 80 C (176 F). Untreated native reservoir water was found to cause serious porosity and

PREFERRED WATERFLOOD MANAGEMENT PRACTICES FOR THE SPRABERRY TREND AREA

Energy Technology Data Exchange (ETDEWEB)

David S. Schechter

2004-08-31

The naturally fractured Spraberry Trend Area is one of the largest reservoirs in the domestic U.S. and is the largest reservoir in area extent in the world. Production from Spraberry sands is found over a 2,500 sq. mile area and Spraberry reservoirs can be found in an eight county area in west Texas. Over 150 operators produce 65,000 barrels of oil per day (bopd) from the Spraberry Trend Area from more than 9,000 production wells. Recovery is poor, on the order of 7-10% due to the profoundly complicated nature of the reservoir, yet billions of barrels of hydrocarbons remain. We estimate over 15% of remaining reserves in domestic Class III reservoirs are in Spraberry Trend Area reservoirs. This tremendous domestic asset is a prime example of an endangered hydrocarbon resource in need of immediate technological advancements before thousands of wells are permanently abandoned. This report describes the final work of the project, ''Preferred Waterflood Management Practices for the Spraberry Trend Area.'' The objective of this project is to significantly increase field-wide production in the Spraberry Trend in a short time frame through the application of preferred practices for managing and optimizing water injection. Our goal is to dispel negative attitudes and lack of confidence in water injection and to document the methodology and results for public dissemination to motivate waterflood expansion in the Spraberry Trend. This objective has been accomplished through research in three areas: (1) detail historical review and extensive reservoir characterization, (2) production data management, and (3) field demonstration. This provides results of the final year of the three-year project for each of the three areas.

Dynamics of waterflooding massive oil deposits in the Chechen Ingush ASSR, including fissured reservoirs in the late stages of development

Energy Technology Data Exchange (ETDEWEB)

Tatashev, K.Kh.; Soboleva, G.N.; Tagunova, A.V.

1979-01-01

In 1956 in the Chechen Ingush ASSR a number of massive oil deposits located in fissured cavernous Upper Cretaceous limestone were developed. The deposits were developed by water-oil displacement from the edges and pericline toward the dome of the structure using the natural water pressure drive as well as artificial marginal flooding. The great oil-bearing capacity, the good hydrodynamic link with the deposit, the close magnitude of oil viscosity and water under the layer conditions and the significant difference in their density (0.4-0.5 g/cm/sup 3/) practically guarantees pistonlike oil displacement. Based on the deposit's geologic-physical characteristics, the late stage of development may be characterized by noncontinuous time and a sharp increase in well waterflooding to maintain full flooding. However, the data obtained from working the field suggest that a sharp increase in waterflooding will be substituted by a slow increase, by stabilization and possibly even a decrease in the percentage of water over the last 3-6 years. This occurred in a number of cases where measures were taken to limit the liquid flow, to periodically operate the well with isolated waterflooding and pereclinal perforation at intervals. This also occurred in a number of cases where the rate of fluid yield was naturally lowered by decreasing the number of producing wells due to waterflooding and disengagement. To more completely extract the oil from relatively low permeable areas of the deposits and to develop them in the later stages, it is useful to use a slow tempo once all wells have been brought to perclinal interval operation.

Pore Scale Investigation of Wettability Alteration Through Chemically-Tuned Waterflooding in Oil-Wet Carbonate Rocks Using X-Ray Micro-Ct Imaging

Science.gov (United States)

Tawfik, M. S.; Karpyn, Z.

2017-12-01

Carbonate reservoirs host more than half of the remaining oil reserves worldwide. Due to their complex pore structure and intermediate to oil-wet nature, it is challenging to produce the remaining oil from these formations. For two decades, chemically tuned waterflooding (CTWF) has gained the attention of many researchers. Experimental, numerical, and field studies suggest that changes in ion composition of injected brine can increase oil recovery in carbonate reservoirs via wettability alteration. However, previous studies explaining the improvement in oil recovery by wettability alteration deduce wettability based on indirect measurements, including sessile drop contact angle measurements on polished rocks, relative permeability, chromatographic separation of SCN- and potential determining ions (PDIs), etc. CTWF literature offers no direct measurement of wettability alteration at the pore scale. This study proposes a direct pore-scale measurement of changes in interfacial curvatures before and after CTWF. Micro-coreflood experiments are performed to investigate the effect of injection brine salinity, ion composition and temperature on rock wettability at the pore scale. X-ray micro-CT scanning is used to obtain 3D image sets to calculate in-situ contact angle distributions. The study also aims to find a correlation between the magnitude of improvement in oil recovery at the macro-scale and the corresponding contact angle distribution at the pore-scale at different experimental conditions. Hence, macro-scale coreflood experiments are performed using the same conditions as the micro-corefloods. Macro-scale coreflood experiments have shown that brines with higher concentration of Ca2+, Mg2+ and SO42- ions have higher recoveries compared to standard seawater. This translates to wettability alteration into a more intermediate-wet state. This study enhances the understanding of the pore-scale physico-chemical mechanisms controlling wettability alteration via CTWF

Criticality-safety analyses of compacted and water-flooded. SP-100 reactors

International Nuclear Information System (INIS)

Brandon, D.I.; Sapir, J.L.

1986-01-01

Reactivity calculations were performed to determine the sensitivity of three liquid metal-cooled, fast reactor designs to various accident environments. The concepts, proposed for the SP-100 Space Nuclear Power Program, included one thermionic and two fuel-pin designs. Numerous models of each core were developed to analyze the effect of core compaction and of water-flooded lattice spreading. Results indicate that those designs incorporating in-core control are least affected by core compaction and that the thermonic concept can best withstand expansion of the flooded fuel element array

Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II; ANNUAL

International Nuclear Information System (INIS)

Czirr, K.L.; Gaddis, M.P.; Moshell, M.K.

2002-01-01

The principle objective of this project is to demonstrate the economic viability and widespread applicability of an innovative reservoir management and carbon dioxide (CO2) flood project development approach for improving CO2 flood project economics in shallow shelf carbonate (SSC) reservoirs

Husky Oil seeks to test new type of waterflood

Energy Technology Data Exchange (ETDEWEB)

1965-04-05

Husky Oil Canada Ltd. is seeking approval from the Alberta Oil and Gas Conservation Board for a new type of water injection at its pilot waterflood test operation in the Lloydminster oil field. Husky has asked permission to modify and enlarge its pilot test to allow injection through the pilot wells of 100,000 bbl of fresh water derived from surface ponds in the vicinity. About 70,000 bbl will be treated with a test polymer to increase its viscosity to 60 cp. Producing the central pilot well until excessive production of polymer occurs has been proposed. It is hoped that the proposed program will verify that oil banks can be created with viscous fluid inside and outside the pilot area.

CO2 Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Annual report, January 1, 1995--December 31, 1995

Energy Technology Data Exchange (ETDEWEB)

Wehner, S.C.; Boomer, R.J.; Cole, R.; Preiditus, J.; Vogt, J.

1996-09-01

The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg/San Andres formation; a light oil, shallow shelf carbonate reservoir within the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico.

Increasing Waterflood Reserves in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

Energy Technology Data Exchange (ETDEWEB)

Clarke, D.; Koerner, R.; Moos D.; Nguyen, J.; Phillips, C.; Tagbor, K.; Walker, S.

1999-04-05

This project used advanced reservoir characterization tools, including the pulsed acoustic cased-hole logging tool, geologic three-dimensional (3-D) modeling software, and commercially available reservoir management software to identify sands with remaining high oil saturation following waterflood. Production from the identified high oil saturated sands was stimulated by recompleting existing production and injection wells in these sands using conventional means as well as a short radius redrill candidate.

Integrated approach towards the application of horizontal wells to improve waterflooding performance. Annual progress report, January 1, 1996--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Kelkar, M.; Liner, C.; Kerr, D.

1997-01-01

This annual report describes the progress during the fourth year of the project on {open_quotes}Integrated Approach Towards the Application of Horizontal Wells to Improve Waterflooding Performance{close_quotes}. The project involves using an integrated approach to characterize the reservoir followed by proposing an appropriate reservoir management strategy to improve the field performance. In the first stage of the project, the type of data we integrated include cross borehole seismic surveys, geological interpretation based on the logs and the cores, and the engineering information. In contrast, during the second stage of the project, we intend to use only conventional data to construct the reservoir description. This report covers the results of the implementation from the first stage of the project. It also discusses the work accomplished so far for the second stage of the project. The production from the Self Unit (location of Stage 1) has sustained an increase of 30 bbls/day over a year with an additional increase anticipated with further implementation. We have collected available core, log and production data from Section 16 in the Berryhill Glenn Unit and have finished the geological description. Based on the geological description and the associated petrophysical properties, we have developed a new indexing procedure for identifying the areas with the most potential. We are also investigating an adjoining tract formerly operated by Chevron where successful miceller-polymer flood was conducted. This will help us in evaluating the reasons for the success of the flood. Armed with this information, we will conduct a detailed geostatistical and flow simulation study and recommend the best reservoir management plan to improve the recovery of the field.

Improved reservoir characterization from waterflood tracer movement, Northwest Fault Block, Prudhoe Bay, Alaska

International Nuclear Information System (INIS)

Nitzberg, K.E.; Broman, W.H.

1992-01-01

This paper reports that simulation models of the Prudhoe Bay Northwest Fault Block (NWFB) waterflood project, with core-plug-derived permeabilities, predicted that injected water would slump because of gravity segregation. Detailed analysis of surveillance logs and production data for one pattern identified tritium tracer breakthrough in surrounding producers without significant slumping. To duplicate the nearly horizontal movement of injected water, a k V /k H ratio that is an order of magnitude lower than previously modeled is required. This improved reservoir characterization led to revision of the reservoir management strategy for the NWFB

Effect of stratification on segregation in carbon dioxide miscible flooding in a water-flooded oil reservoir

International Nuclear Information System (INIS)

Bhatti, A.A.; Mahmood, S.M.; Amjad, B.

2013-01-01

Oil reservoirs are subjected to tertiary recovery by deploying any enhanced oil recovery (EOR) technique for the recovery of left over oil. Amongst many EOR methods one of the widely applied worldwide is CO/sub 2/ flooding through miscible, near miscible or immiscible displacement processes. CO/sub 2/ flooding process responds to a number of reservoir and fluid characteristics. These characteristics have strong effect on overall efficiency of the displacement process. Better understanding of the effect of different characteristics on displacement process is important to plan an efficient displacement process. In this work, the effect of stratification resulting in gravity segregation of the injected fluid is studied in an oil reservoir which is water-flooded during secondary phase of recovery. Sensitivity analysis is performed through successive simulation on Eclipse 300 (compositional) reservoir simulator. Process involves the continuous CO/sub 2/ injection in an oil reservoir with more than 1/3rd of original oil in place left after water flooding. Reservoir model with four different permeability layers is studied. Four patterns by changing the arrangement of the permeabilities of the layers are analysed. The effect of different arrangement or stratification on segregation of CO/sub 2/ and ultimately on the incremental oil recovery, is investigated. It has been observed that out of four arrangements, upward fining pattern relatively overcame the issue of the segregation of CO/sub 2/ and consequently 33% more oil with half injection volume is recovered when compared with the downward fining pattern. (author)

Expanding the experience of using non-stationary waterflooding technology with changing direction of the filtration flow in the example of the Northern Buzachi field

Directory of Open Access Journals (Sweden)

E.M. Almukhametova

2018-06-01

Full Text Available Abstract. The last few years, work has been carried out to study the effectiveness of non-stationary exposure in the highly viscous oil field Northern Buzachi (Republic of Kazakhstan. It has been proved that this technology is quite effective in the development of highly viscous oil reservoirs, however, in order to constantly maintain high technological effect, a constant modification of this technology is required, since it has a characteristic feature of rapid «aging». Further search for the conditions of effective application of non-stationary exposure on highly-viscous oil deposits can be carried out in two directions: the implementation of non-stationary exposure in new areas with other reservoir parameters and the change in the parameters of non-stationary exposure technology (including combining with other technologies in areas where this technology is already in use. Both approaches are used on the Northern Buzachi field. Thus, the positive experience of using non-stationary waterflooding in combination with changing direction of the filtration flow in the section of the seventh block of the Northern Buzachi field allowed us to recommend new sites for the implementation of this technology. With the participation of the author of this work, a non-stationary waterflooding program was developed and implemented on the site of the sixth block (south of the first operational facility.

Experimental use of produced waters for waterflooding fields of Kuibyshev region

Energy Technology Data Exchange (ETDEWEB)

Palii, P A; Gavura, V E; Redkin, I I; Sokolov, A G

1970-01-01

Large volumes of produced waters have been used for waterflooding in the Kuibyshev region. Before underground injection, the water is conditioned by short-term storage. The treated water contains emulsified oil, suspended solids, hydrogen sulfide, and ferrous iron. This water is readily injected into fractured porous formations, even if suspended solids reach 42 mg/liter and emulsifed oil 67 mg/liter. However, better quality water has to be injected into nonfractured formations. In this case, the concentration of emulsified oil and suspended solids needs to be kept below 5 mg/liter. If concentration of suspended material exceeds this limit, water injectivity decreases rapidly. The partially plugged wells can be restored by acid treatment. Water injection has shown large economic gains in this region.

Estimation of critical gas saturation during pressure depletion in virgin and waterflooded reservoirs

Energy Technology Data Exchange (ETDEWEB)

McDougall, S.R.; Sorbie, K.S. [Heriot-Watt Univ., Dept. of Petroleum Engineering, Edinburgh (United Kingdom)

1999-08-01

An important issue in petroleum engineering is the prediction of gas production during reservoir depletion - either following conventional waterflooding operations or in the early stages of hydrocarbon production. The estimation of critical gas saturation for use in corresponding simulation studies is clearly a primary concern. To this end, a 3D, three-phase numerical pore-scale simulator has been developed that can be used to estimate critical gas saturations over a range of different lengthscales and for a wide range of fluid and rock properties. The model incorporates a great deal of the known physics observed in associated laboratory micromodel experiments, including embryonic nucleation, supersaturation effects, multiphase diffusion, bubble growth/migration/fragmentation, oil shrinkage, and three-phase spreading coefficients. These precise pore-scale mechanisms governing gas evolution have been found to be far more subtle than earlier models would suggest because of the large variation of gas/oil interfacial tension (IFT) with pressure. This has a profound effect upon the migration of gas structures during depletion. In models pertaining to reservoir rock, the process of gas migration is consequently much slower than predictions from more simplistic models would imply. This is the first time that bubble fragmentation and IFT variations have been included in a model of gas evolution at the pore-scale and the implications for production forecasting are expected to be significant. In addition, novel scaling groups have been derived for a number of different facies under both virgin and waterflooded conditions. One future application of these groups would be to scale S{sub gc} values obtained from high rate depressurization experiments to the low rate conditions more characteristic of field operations. (Author)

Economic effectiveness of intensification of oil production from strongly waterflooded Chokrakskii and Karaganskii formations of Oktyabrskii field

Energy Technology Data Exchange (ETDEWEB)

Titova, N I; Umanskii, M M

1969-09-01

The forced method of exploitation was initiated at Oktyabrskii field in 1943. In this method, the wells are equipped with submerged electric pumps.From 1943 to 1967, this method of pumping wells with highly water-cut production, recovered an additional 1,876 tons of oil. Better results were obtained when the forced exploitation method was combined with waterflooding. The high profitability of using submerged centrifugal pumps in oil wells with high water production is shown. Year-by-year results obtained with this production method are shown in 4 tables.

CO{sub 2} huff-n-puff process in a light oil shallow carbonate reservoir. Annual report, January 1, 1996--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Prieditis, J.; Wehner, S.

1998-01-01

The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations; a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Miscible CO{sub 2} flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin`s daily production. There are significant probable reserves associated with future miscible CO{sub 2} projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO{sub 2} H-n-P process is being investigated as a near-term option to mitigate the negative cash-flow situation--allowing acceleration of inventoried miscible CO{sub 2} projects when coupled together.

Assessment of potential increased oil production by polymer-waterflood in northern and southern mid-continent oil fields. Progress report for the quarter ending September 30, 1978

Energy Technology Data Exchange (ETDEWEB)

1978-10-15

Activities in programs to conduct polymer-waterflood studies are reported. During the period a study was conducted of the Burbank-Bartlesville sand reservoir, located in the north half of the Stanley Stringer Field, Osage County, Oklahoma. Progress in the overall program is summarized in a chart. (JRD)

Diversity of Metabolically Active Bacteria in Water-Flooded High-Temperature Heavy Oil Reservoir

Directory of Open Access Journals (Sweden)

Tamara N. Nazina

2017-04-01

Full Text Available The goal of this work was to study the overall genomic diversity of microorganisms of the Dagang high-temperature oilfield (PRC and to characterize the metabolically active fraction of these populations. At this water-flooded oilfield, the microbial community of formation water from the near-bottom zone of an injection well where the most active microbial processes of oil degradation occur was investigated using molecular, cultural, radiotracer, and physicochemical techniques. The samples of microbial DNA and RNA from back-flushed water were used to obtain the clone libraries for the 16S rRNA gene and cDNA of 16S rRNA, respectively. The DNA-derived clone libraries were found to contain bacterial and archaeal 16S rRNA genes and the alkB genes encoding alkane monooxygenases similar to those encoded by alkB-geo1 and alkB-geo6 of geobacilli. The 16S rRNA genes of methanogens (Methanomethylovorans, Methanoculleus, Methanolinea, Methanothrix, and Methanocalculus were predominant in the DNA-derived library of Archaea cloned sequences; among the bacterial sequences, the 16S rRNA genes of members of the genus Geobacillus were the most numerous. The RNA-derived library contained only bacterial cDNA of the 16S rRNA sequences belonging to metabolically active aerobic organotrophic bacteria (Tepidimonas, Pseudomonas, Acinetobacter, as well as of denitrifying (Azoarcus, Tepidiphilus, Calditerrivibrio, fermenting (Bellilinea, iron-reducing (Geobacter, and sulfate- and sulfur-reducing bacteria (Desulfomicrobium, Desulfuromonas. The presence of the microorganisms of the main functional groups revealed by molecular techniques was confirmed by the results of cultural, radioisotope, and geochemical research. Functioning of the mesophilic and thermophilic branches was shown for the microbial food chain of the near-bottom zone of the injection well, which included the microorganisms of the carbon, sulfur, iron, and nitrogen cycles.

Assessment of potential increased oil production by polymer-waterflood in northern and southern mid-continent oil fields. Final report

Energy Technology Data Exchange (ETDEWEB)

Pease, R.W.; Durham, E.N.; Watson, J.A.

1979-09-01

A conventional waterflood in the North Stanley Field, Osage County, Oklahoma, nearing the economic limit, was modified by substituting an aqueous solution of polyacrylamides for brine as the intected fluid. Remedial operations on existing facilities were performed before polymer injection began. Positive oil production response was achieved from this 1000-acre project, a maximum EOR production rate of about 200 barrels per day being achieved within 1-1/2 years after the start of polymer injection. Based on performance to January 1979, ultimate EOR recovery is estimated at 500,000 barrels.

Carbon Dioxide Removal via Passive Thermal Approaches

Science.gov (United States)

Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

2011-01-01

A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

Fine Formation During Brine-Crude Oil-Calcite Interaction in Smart Water Enhanced Oil Recovery for Caspian Carbonates

DEFF Research Database (Denmark)

Chakravarty, Krishna Hara; Fosbøl, Philip Loldrup; Thomsen, Kaj

2015-01-01

Modified sea water has been shown to affect the oil recovery fraction considerably during secondary and tertiary waterfloods. Available soluble potential ions (i.e. Ca2+, Mg2+ & SO42-) in the interacting waterflood (ITW) are suggested to play a key role in increasing the displacement efficiency...... of oil. In previous studies, compositions of injected waterfloods (IJW) have been correlated to the observed oil recovery. This study highlights differences between IJW and ITW for different studies reported in literature....

Sweep efficiency improvement of waterfloods in Steelman Units V and VII through the application of computer models

Energy Technology Data Exchange (ETDEWEB)

Woods, W S

1967-01-01

The use of a digital computer program as a tool to investigate the position of flood fronts in 2 Steelman units is described. The program involves a simulated potentiometric analyzer. Several years of historical performance were utilized and alterations to the model were made to match the historical performance until a satisfactory prediction is obtained. Subsequent to matching the historical performance, future predictions were obtained to evaluate the efficiency of the ultimate sweep configuration in the reservoir. These data are used as directives for improving the operation of the waterfloods. Rather than the complicated and elaborate computer techniques currently in use, it is suggested that the results obtained in this particular application of simple techniques provide sufficient economic operating directives.

Sustaining the emerging carbon trading industry development: A business ecosystem approach of carbon traders

International Nuclear Information System (INIS)

Hu, Guangyu; Rong, Ke; Shi, Yongjiang; Yu, Jing

2014-01-01

This paper explores how carbon traders nurture the business ecosystem to sustain the emerging carbon trading industry development. We collected primary data from a multinational carbon trader and its ecosystem partners in China, through the construction of interviews and documentary. The research findings show the carbon trading industry has experienced four-stage evolution with different driving forces; the carbon trader attracted and organized ecosystem partners to facilitate the CDM project owners to create carbon credits and trade them; a systematic business ecosystems approach through the lens of Context, Cooperation and Configuration, initiated by carbon traders, has facilitated the industry development. Our findings also implicate to industrial practitioners and policymakers for sustaining the emerging industry development at both the current- and the post-Kyoto protocol periods. - Highlights: • The carbon trader is a catalyst to link CDM project owner and trading market in China • The evolution of carbon trading industry has four stages with various driving forces. • Nurturing business ecosystems facilitates the carbon trading industry development. • The ecosystem approach works via the lens of Context, Configuration and Cooperation. • The ecosystem approach implicates to carbon trading industry at the post-Kyoto era

Smart Waterflooding in Carbonate Reservoirs

DEFF Research Database (Denmark)

Zahid, Adeel

brine solutions regarding phase behavior and viscosity measurements. This difference is attributed to the difference in composition of the different crude oils. More experiments are carried out in order to understand mechanisms of the crude oil viscosity reduction and emulsion formation. We observed...... with and without aging. The total oil recovery, recovery rate and interaction mechanisms of ions with rock were studied for different injected fluids under different temperatures and wettability conditions. Experimental results demonstrate that the oil recovery mechanism under high salinity seawater flooding...... phase could be the possible reasons for the observed increase in oil recovery with sulfate ions at high temperature in chalk reservoirs, besides the mechanism of the rock wettability alteration. * Crude oil/brine interaction study suggests that viscosity reduction for crude oil in contact with brine...

Application of a quadratic method of programming to a particular problem of a rational development of a waterflooded field

Energy Technology Data Exchange (ETDEWEB)

Korotkov, S F; Khalitov, N T

1965-01-01

he quadratic method of programming is used to solve the following type of problem. A circular reservoir is subjected to a peripheral waterflood. The reservoir is drained by wells arranged in 3 concentric circles. The objective is to control the operation of producing wells, that a maximum quantity of water-free oil will be produced. The wells are flowed so that bottomhole pressure is above the bubble point. A quadratic equation is used to express the essential features of the problem; a system of linear equations is used to express the boundary conditions. The problem is solved by means of the Wolf algorithm method. The method is demonstrated by an illustrative example.

Heavy-oil recovery in naturally fractured reservoirs with varying wettability by steam solvent co-injection

Energy Technology Data Exchange (ETDEWEB)

Al Bahlani, A. [Alberta Univ., Edmonton, AB (Canada); Babadagli, T. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Alberta Univ., Edmonton, AB (Canada)

2008-10-15

Steam injection may not be an efficient oil recovery process in certain circumstances, such as in deep reservoirs, where steam injection may be ineffective because of hot-water flooding due to excessive heat loss. Steam injection may also be ineffective in oil-wet fractured carbonates, where steam channels through fracture zones without effectively sweeping the matrix oil. Steam flooding is one of the many solutions for heavy oil recovery in unconsolidated sandstones that is in commercial production. However, heavy-oil fractured carbonates are more challenging, where the recovery is generally limited only to matrix oil drainage gravity due to unfavorable wettability or thermal expansion if heat is introduced during the process. This paper proposed a new approach to improve steam/hot-water injection and efficiency for heavy-oil fractured carbonate reservoirs. The paper provided background information on oil recovery from fractured carbonates and provided a statement of the problem. Three phases were described, including steam/hot-waterflooding phase (spontaneous imbibition); miscible flooding phase (diffusion); and steam/hot-waterflooding phase (spontaneous imbibition or solvent retention). The paper also discussed core preparation and saturation procedures. It was concluded that efficient oil recovery is possible using alternate injection of steam/hot water and solvent. 43 refs., 1 tab., 13 figs.

Methods and compositions for improving secondary recovery of oil

Energy Technology Data Exchange (ETDEWEB)

Marlowe, B.; Raymond, R.L.; Douros, J.D. Jr.

1964-12-22

In a waterflood process, the waterflood is improved by incorporating with it a microorganism growth-inhibiting amount of a di-substituted naphthalene of the structure: wherein R and R's are substituents selected from the group consisting of (1) hydroxy, (2) hydroxyalkyl, (3) carboxy, (4) the salts of carboxy, and (5) the oxides of hydroxynaphthalene (the hydroxyalkyl and carboxy substituents each having from 1 to 6 carbon atoms). (7 claims)

Tropical forest carbon assessment: integrating satellite and airborne mapping approaches

International Nuclear Information System (INIS)

Asner, Gregory P

2009-01-01

Large-scale carbon mapping is needed to support the UNFCCC program to reduce deforestation and forest degradation (REDD). Managers of forested land can potentially increase their carbon credits via detailed monitoring of forest cover, loss and gain (hectares), and periodic estimates of changes in forest carbon density (tons ha -1 ). Satellites provide an opportunity to monitor changes in forest carbon caused by deforestation and degradation, but only after initial carbon densities have been assessed. New airborne approaches, especially light detection and ranging (LiDAR), provide a means to estimate forest carbon density over large areas, which greatly assists in the development of practical baselines. Here I present an integrated satellite-airborne mapping approach that supports high-resolution carbon stock assessment and monitoring in tropical forest regions. The approach yields a spatially resolved, regional state-of-the-forest carbon baseline, followed by high-resolution monitoring of forest cover and disturbance to estimate carbon emissions. Rapid advances and decreasing costs in the satellite and airborne mapping sectors are already making high-resolution carbon stock and emissions assessments viable anywhere in the world.

Characterization and Alteration of Wettability States of Alaskan Reserviors to Improve Oil Recovery Efficiency (including the within-scope expansion based on Cyclic Water Injection - a pulsed waterflood for Enhanced Oil Recovery)

Energy Technology Data Exchange (ETDEWEB)

Abhijit Dandekar; Shirish Patil; Santanu Khataniar

2008-12-31

Numerous early reports on experimental works relating to the role of wettability in various aspects of oil recovery have been published. Early examples of laboratory waterfloods show oil recovery increasing with increasing water-wetness. This result is consistent with the intuitive notion that strong wetting preference of the rock for water and associated strong capillary-imbibition forces gives the most efficient oil displacement. This report examines the effect of wettability on waterflooding and gasflooding processes respectively. Waterflood oil recoveries were examined for the dual cases of uniform and non-uniform wetting conditions. Based on the results of the literature review on effect of wettability and oil recovery, coreflooding experiments were designed to examine the effect of changing water chemistry (salinity) on residual oil saturation. Numerous corefloods were conducted on reservoir rock material from representative formations on the Alaska North Slope (ANS). The corefloods consisted of injecting water (reservoir water and ultra low-salinity ANS lake water) of different salinities in secondary as well as tertiary mode. Additionally, complete reservoir condition corefloods were also conducted using live oil. In all the tests, wettability indices, residual oil saturation, and oil recovery were measured. All results consistently lead to one conclusion; that is, a decrease in injection water salinity causes a reduction in residual oil saturation and a slight increase in water-wetness, both of which are comparable with literature observations. These observations have an intuitive appeal in that water easily imbibes into the core and displaces oil. Therefore, low-salinity waterfloods have the potential for improved oil recovery in the secondary recovery process, and ultra low-salinity ANS lake water is an attractive source of injection water or a source for diluting the high-salinity reservoir water. As part of the within-scope expansion of this project

Constructing post-carbon institutions: Assessing EU carbon reduction efforts through an institutional risk governance approach

International Nuclear Information System (INIS)

LaBelle, Michael

2012-01-01

This paper examines three different governance approaches the European Union (EU) and Member States (MS) are relying on to reach a low carbon economy by 2050. Current governance literature explains the operational methods of the EU's new governance approach to reduce carbon emissions. However, the literature neglects to account for the perceived risks that inhibit the roll-out of new low carbon technology. This article, through a novel approach, uses a grounded theoretical framework to reframe traditional risk literature and provides a connection to governance literature in order to assess the ability of EU governance mechanisms to reduce carbon emissions. The empirical research is based on responses from European energy stakeholders who participated in a Delphi method discussion and in semi-structured interviews; these identified three essential requirements for carbon emissions to be reduced to near zero by 2050: (1) an integrated European energy network, (2) carbon pricing and (3) demand reduction. These features correspond to institutionalized responses by the EU and MS: the Agency for the Cooperation of Energy Regulators (ACER); European Union Emission Trading Scheme (EU ETS) and energy efficiency directives and policies integrated into existing MS institutions. The theoretical and empirical findings suggest that governance by facilitation (energy efficiency) fails to induce significant investment and new policy approaches and cannot be relied on to achieve requisite reductions in demand. Governance by negotiation (ACER) and governance by hierarchy (EU ETS) do reduce risks and may encourage the necessary technological uptake. The term ‘risk governance’ is used to explain the important role governance plays in reducing risks and advancing new technology and thereby lowering carbon emissions in the energy sector. - Highlights: ► This article assesses the role of EU institutions in reducing carbon emissions by 2050. ► Empirical research is based on Delphi

Molecular analysis of the microbial community structures in water-flooding petroleum reservoirs with different temperatures

Science.gov (United States)

Wang, L.-Y.; Duan, R.-Y.; Liu, J.-F.; Yang, S.-Z.; Gu, J.-D.; Mu, B.-Z.

2012-04-01

Temperature is one of the most important environmental factors regulating the activity and determining the composition of the microbial community. Analysis of microbial communities from six water-flooding petroleum reservoirs at temperatures from 20 to 63 °C by 16S rRNA gene clone libraries indicates the presence of physiologically diverse and temperature-dependent microorganisms in these subterrestrial ecosystems. In high-temperature petroleum reservoirs, most of the archaeal sequences belong to the thermophilic archaea including the genera Thermococcus, Methanothermobacter and Thermoplasmatales, most of the bacterial sequences belong to the phyla Firmicutes, Thermotogae and Thermodesulfobacteria; in low-temperature petroleum reservoirs, most of the archaeal sequences are affiliated with the genera Methanobacterium, Methanoculleus and Methanocalculus, most of the bacterial sequences to the phyla Proteobacteria, Bacteroidetes and Actinobacteria. Canonical correspondence analysis (CCA) revealed that temperature, mineralization, ionic type as well as volatile fatty acids showed correlation with the microbial community structures. These organisms may be adapted to the environmental conditions of these petroleum reservoirs over geologic time by metabolizing buried organic matter from the original deep subsurface environment and became the common inhabitants in subsurface environments.

Comparison of Microbial Community Compositions of Injection and Production Well Samples in a Long-Term Water-Flooded Petroleum Reservoir

Science.gov (United States)

Ren, Hong-Yan; Zhang, Xiao-Jun; Song, Zhi-yong; Rupert, Wieger; Gao, Guang-Jun; Guo, Sheng-xue; Zhao, Li-Ping

2011-01-01

Water flooding plays an important role in recovering oil from depleted petroleum reservoirs. Exactly how the microbial communities of production wells are affected by microorganisms introduced with injected water has previously not been adequately studied. Using denaturing gradient gel electrophoresis (DGGE) approach and 16S rRNA gene clone library analysis, the comparison of microbial communities is carried out between one injection water and two production waters collected from a working block of the water-flooded Gudao petroleum reservoir located in the Yellow River Delta. DGGE fingerprints showed that the similarities of the bacterial communities between the injection water and production waters were lower than between the two production waters. It was also observed that the archaeal composition among these three samples showed no significant difference. Analysis of the 16S rRNA gene clone libraries showed that the dominant groups within the injection water were Betaproteobacteria, Gammaproteobacteria and Methanomicrobia, while the dominant groups in the production waters were Gammaproteobacteria and Methanobacteria. Only 2 out of 54 bacterial operational taxonomic units (OTUs) and 5 out of 17 archaeal OTUs in the injection water were detected in the production waters, indicating that most of the microorganisms introduced by the injection water may not survive to be detected in the production waters. Additionally, there were 55.6% and 82.6% unique OTUs in the two production waters respectively, suggesting that each production well has its specific microbial composition, despite both wells being flooded with the same injection water. PMID:21858049

Climate change and JI options for India - a carbon-sink approach

International Nuclear Information System (INIS)

Kadekodi, G.K.

1995-01-01

Three approaches to producing carbon dioxide arising from the Framework Convention on Climate Change are discussed. These are emission cap approach, fiscal or carbon tax and joint implementation. These are examined from an Indian perspective. More work on the economic, sociological and political aspects is recommended. (UK)

Practical modeling approaches for geological storage of carbon dioxide.

Science.gov (United States)

Celia, Michael A; Nordbotten, Jan M

2009-01-01

The relentless increase of anthropogenic carbon dioxide emissions and the associated concerns about climate change have motivated new ideas about carbon-constrained energy production. One technological approach to control carbon dioxide emissions is carbon capture and storage, or CCS. The underlying idea of CCS is to capture the carbon before it emitted to the atmosphere and store it somewhere other than the atmosphere. Currently, the most attractive option for large-scale storage is in deep geological formations, including deep saline aquifers. Many physical and chemical processes can affect the fate of the injected CO2, with the overall mathematical description of the complete system becoming very complex. Our approach to the problem has been to reduce complexity as much as possible, so that we can focus on the few truly important questions about the injected CO2, most of which involve leakage out of the injection formation. Toward this end, we have established a set of simplifying assumptions that allow us to derive simplified models, which can be solved numerically or, for the most simplified cases, analytically. These simplified models allow calculation of solutions to large-scale injection and leakage problems in ways that traditional multicomponent multiphase simulators cannot. Such simplified models provide important tools for system analysis, screening calculations, and overall risk-assessment calculations. We believe this is a practical and important approach to model geological storage of carbon dioxide. It also serves as an example of how complex systems can be simplified while retaining the essential physics of the problem.

CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

Energy Technology Data Exchange (ETDEWEB)

Boomer, R.J.; Cole, R.; Kovar, M.; Prieditis, J.; Vogt, J.; Wehner, S.

1999-02-24

The application cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in capital-intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in a attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir.

Moving carbonation fronts in concrete: a moving-sharp-interface approach

NARCIS (Netherlands)

Muntean, A.; Böhm, M.; Kropp, J.

2011-01-01

We present a new modeling strategy for predicting the penetration of carbonation reaction fronts in concrete. The approach relies on the assumption that carbonation reaction concentrates macroscopically on an a priori unknown narrow strip (called reaction front) moving into concrete gradually

The GLOBE Carbon Cycle Project: Using a systems approach to understand carbon and the Earth's climate system

Science.gov (United States)

Silverberg, S. K.; Ollinger, S. V.; Martin, M. E.; Gengarelly, L. M.; Schloss, A. L.; Bourgeault, J. L.; Randolph, G.; Albrechtova, J.

2009-12-01

National Science Content Standards identify systems as an important unifying concept across the K-12 curriculum. While this standard exists, there is a recognized gap in the ability of students to use a systems thinking approach in their learning. In a similar vein, both popular media as well as some educational curricula move quickly through climate topics to carbon footprint analyses without ever addressing the nature of carbon or the carbon cycle. If students do not gain a concrete understanding of carbon’s role in climate and energy they will not be able to successfully tackle global problems and develop innovative solutions. By participating in the GLOBE Carbon Cycle project, students learn to use a systems thinking approach, while at the same time, gaining a foundation in the carbon cycle and it's relation to climate and energy. Here we present the GLOBE Carbon Cycle project and materials, which incorporate a diverse set of activities geared toward upper middle and high school students with a variety of learning styles. A global carbon cycle adventure story and game let students see the carbon cycle as a complete system, while introducing them to systems thinking concepts including reservoirs, fluxes and equilibrium. Classroom photosynthesis experiments and field measurements of schoolyard vegetation brings the global view to the local level. And the use of computer models at varying levels of complexity (effects on photosynthesis, biomass and carbon storage in global biomes, global carbon cycle) not only reinforces systems concepts and carbon content, but also introduces students to an important scientific tool necessary for understanding climate change.

Peatland geoengineering: an alternative approach to terrestrial carbon sequestration.

Science.gov (United States)

Freeman, Christopher; Fenner, Nathalie; Shirsat, Anil H

2012-09-13

Terrestrial and oceanic ecosystems contribute almost equally to the sequestration of ca 50 per cent of anthropogenic CO(2) emissions, and already play a role in minimizing our impact on Earth's climate. On land, the majority of the sequestered carbon enters soil carbon stores. Almost one-third of that soil carbon can be found in peatlands, an area covering just 2-3% of the Earth's landmass. Peatlands are thus well established as powerful agents of carbon capture and storage; the preservation of archaeological artefacts, such as ancient bog bodies, further attest to their exceptional preservative properties. Peatlands have higher carbon storage densities per unit ecosystem area than either the oceans or dry terrestrial systems. However, despite attempts over a number of years at enhancing carbon capture in the oceans or in land-based afforestation schemes, no attempt has yet been made to optimize peatland carbon storage capacity or even to harness peatlands to store externally captured carbon. Recent studies suggest that peatland carbon sequestration is due to the inhibitory effects of phenolic compounds that create an 'enzymic latch' on decomposition. Here, we propose to harness that mechanism in a series of peatland geoengineering strategies whereby molecular, biogeochemical, agronomical and afforestation approaches increase carbon capture and long-term sequestration in peat-forming terrestrial ecosystems.

Evaluations of carbon fluxes estimated by top-down and bottom-up approaches

Science.gov (United States)

Murakami, K.; Sasai, T.; Kato, S.; Hiraki, K.; Maksyutov, S. S.; Yokota, T.; Nasahara, K.; Matsunaga, T.

2013-12-01

There are two types of estimating carbon fluxes using satellite observation data, and these are referred to as top-down and bottom-up approaches. Many uncertainties are however still remain in these carbon flux estimations, because the true values of carbon flux are still unclear and estimations vary according to the type of the model (e.g. a transport model, a process based model) and input data. The CO2 fluxes in these approaches are estimated by using different satellite data such as the distribution of CO2 concentration in the top-down approach and the land cover information (e.g. leaf area, surface temperature) in the bottom-up approach. The satellite-based CO2 flux estimations with reduced uncertainty can be used efficiently for identifications of large emission area and carbon stocks of forest area. In this study, we evaluated the carbon flux estimates from two approaches by comparing with each other. The Greenhouse gases Observing SATellite (GOSAT) has been observing atmospheric CO2 concentrations since 2009. GOSAT L4A data product is the monthly CO2 flux estimations for 64 sub-continental regions and is estimated by using GOSAT FTS SWIR L2 XCO2 data and atmospheric tracer transport model. We used GOSAT L4A CO2 flux as top-down approach estimations and net ecosystem productions (NEP) estimated by the diagnostic type biosphere model BEAMS as bottom-up approach estimations. BEAMS NEP is only natural land CO2 flux, so we used GOSAT L4A CO2 flux after subtraction of anthropogenic CO2 emissions and oceanic CO2 flux. We compared with two approach in temperate north-east Asia region. This region is covered by grassland and crop land (about 60 %), forest (about 20 %) and bare ground (about 20 %). The temporal variation for one year period was indicated similar trends between two approaches. Furthermore we show the comparison of CO2 flux estimations in other sub-continental regions.

Results of analyzing natural gas during the use of biochemical processes in a petroleum deposit

Energy Technology Data Exchange (ETDEWEB)

Yulbarisov, E M

1972-01-01

Laboratory and commercial scale experiments with a geobioreagent and the Arlanskii deposit petroleum gave a sharp increase in the content of heavier hydrocarbons, nitrogen, and carbon dioxide in the gas and an increase in the yield of gasoline fraction boiling below 122/sup 0/C. The commercial scale experiments were done in a stratum 1200 m deep during waterflood recovery at 200 kg/cm/sup 2/. A substantial increase in ethane and higher hydrocarbons in the gas and increased petroleum yield were observed, especially after each waterflood. The effect of water was explained by higher activity of the bacteria at a lower concentration of rock salts.

An approach to a black carbon emission inventory for Mexico by two methods

International Nuclear Information System (INIS)

Cruz-Núñez, Xochitl

2014-01-01

A black carbon (BC) emission inventory for Mexico is presented. Estimate was performed by using two approaches, based on fuel consumption and emission factors in a top-down scheme, and the second from PM25 emission data and its correlation with black carbon by source category, assuming that black carbon = elemental carbon. Results show that black carbon emissions are in interval 53–473 Gg using the fuel consumption approach and between 62 and 89 using the sector method. Black carbon key sources come from biomass burning in the rural sector, with 47 percent share to the National total. Mobile sources emissions account to 16% to the total. An opportunity to reduce, in the short-term, carbon dioxide equivalent (CO2-eq) emissions by reducing black carbon emissions would be obtained in reducing emissions mainly from biomass burning in rural housing sector and diesel emissions in the transport sector with important co-benefits in direct radiative forcing, public health and air quality. - Highlights: • Black carbon emissions are estimated between 53 and 473 Gg/year on a fuel consumption method. • Black carbon emissions are estimated between 62 and 89 Gg/year on a sector method

An approach to a black carbon emission inventory for Mexico by two methods

Energy Technology Data Exchange (ETDEWEB)

Cruz-Núñez, Xochitl, E-mail: xcruz@unam.mx

2014-05-01

A black carbon (BC) emission inventory for Mexico is presented. Estimate was performed by using two approaches, based on fuel consumption and emission factors in a top-down scheme, and the second from PM25 emission data and its correlation with black carbon by source category, assuming that black carbon = elemental carbon. Results show that black carbon emissions are in interval 53–473 Gg using the fuel consumption approach and between 62 and 89 using the sector method. Black carbon key sources come from biomass burning in the rural sector, with 47 percent share to the National total. Mobile sources emissions account to 16% to the total. An opportunity to reduce, in the short-term, carbon dioxide equivalent (CO2-eq) emissions by reducing black carbon emissions would be obtained in reducing emissions mainly from biomass burning in rural housing sector and diesel emissions in the transport sector with important co-benefits in direct radiative forcing, public health and air quality. - Highlights: • Black carbon emissions are estimated between 53 and 473 Gg/year on a fuel consumption method. • Black carbon emissions are estimated between 62 and 89 Gg/year on a sector method.

Alkaline Waterflooding Demonstration Project, Ranger Zone, Long Beach Unit, Wilmington Field, California. Fourth annual report, June 1979-May 1980. Volume 3. Appendices II-XVII

Energy Technology Data Exchange (ETDEWEB)

Carmichael, J.D.

1981-03-01

Volume 3 contains Appendices II through XVII: mixing instructions for sodium orthosilicate; oil displacement studies using THUMS C-331 crude oil and extracted reservoir core material from well B-110; clay mineral analysis of B-827-A cores; sieve analysis of 4 Fo sand samples from B-110-IA and 4 Fo sand samples from B-827-A; core record; delayed secondary caustic consumption tests; long-term alkaline consumption in reservoir sands; demulsification study for THUMS Long Beach Company, Island White; operating plans and instructions for DOE injection demonstration project, alkaline injection; caustic pilot-produced water test graphs; well test irregularities (6/1/79-5/31/80); alkaline flood pump changes (6/1/79-5/31/80); monthly DOE pilot chemical waterflood injection reports (preflush injection, alkaline-salt injection, and alkaline injection without salt); and caustic safety procedures-alkaline chemicals.

A simple approach to estimate soil organic carbon and soil co/sub 2/ emission

International Nuclear Information System (INIS)

Abbas, F.

2013-01-01

SOC (Soil Organic Carbon) and soil CO/sub 2/ (Carbon Dioxide) emission are among the indicator of carbon sequestration and hence global climate change. Researchers in developed countries benefit from advance technologies to estimate C (Carbon) sequestration. However, access to the latest technologies has always been challenging in developing countries to conduct such estimates. This paper presents a simple and comprehensive approach for estimating SOC and soil CO/sub 2/ emission from arable- and forest soils. The approach includes various protocols that can be followed in laboratories of the research organizations or academic institutions equipped with basic research instruments and technology. The protocols involve soil sampling, sample analysis for selected properties, and the use of a worldwide tested Rothamsted carbon turnover model. With this approach, it is possible to quantify SOC and soil CO/sub 2/ emission over short- and long-term basis for global climate change assessment studies. (author)

Bridging analytical approaches for low-carbon transitions

Science.gov (United States)

Geels, Frank W.; Berkhout, Frans; van Vuuren, Detlef P.

2016-06-01

Low-carbon transitions are long-term multi-faceted processes. Although integrated assessment models have many strengths for analysing such transitions, their mathematical representation requires a simplification of the causes, dynamics and scope of such societal transformations. We suggest that integrated assessment model-based analysis should be complemented with insights from socio-technical transition analysis and practice-based action research. We discuss the underlying assumptions, strengths and weaknesses of these three analytical approaches. We argue that full integration of these approaches is not feasible, because of foundational differences in philosophies of science and ontological assumptions. Instead, we suggest that bridging, based on sequential and interactive articulation of different approaches, may generate a more comprehensive and useful chain of assessments to support policy formation and action. We also show how these approaches address knowledge needs of different policymakers (international, national and local), relate to different dimensions of policy processes and speak to different policy-relevant criteria such as cost-effectiveness, socio-political feasibility, social acceptance and legitimacy, and flexibility. A more differentiated set of analytical approaches thus enables a more differentiated approach to climate policy making.

Holey carbon micro-arrays for transmission electron microscopy: A microcontact printing approach

International Nuclear Information System (INIS)

Chester, David W.; Klemic, James F.; Stern, Eric; Sigworth, Fred J.; Klemic, Kathryn G.

2007-01-01

We have used a microcontact printing approach to produce high quality and inexpensive holey carbon micro-arrays. Fabrication involves: (1) micromolding a poly(dimethylsiloxane) (PDMS) elastomer stamp from a microfabricated master that contains the desired array pattern; (2) using the PDMS stamp for microcontact printing a thin sacrificial plastic film that contains an array of holes; (3) floating the plastic film onto TEM grids; (4) evaporating carbon onto the plastic film and (5) removing the sacrificial plastic film. The final holey carbon micro-arrays are ready for use as support films in TEM applications with the fidelity of the original microfabricated pattern. This approach is cost effective as both the master and the stamps have long-term reusability. Arbitrary array patterns can be made with microfabricated masters made through a single-step photolithographic process

CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. 1994 Annual report

Energy Technology Data Exchange (ETDEWEB)

Wehner, S.C.

1995-05-01

It is anticipated that this project will show that the application of the CO{sub 2} Huff-n-Puff process in shallow shelf carbonates can be economically implemented to recover appreciable volumes of light oil. The goals of the project are the development of guidelines for cost-effective selection of candidate reservoirs and wells, along with estimating recovery potential. The selected site for the demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Work is nearing completion on the reservoir characterization components of the project. The near-term emphasis is to, (1) provide an accurate distribution of original oil-in-place on a waterflood pattern entity level, (2) evaluate past recovery efficiencies, (3) perform parametric simulations, and (4) forecast performance for a site specific field demonstration of the proposed technology. Macro zonation now exists throughout the study area and cross-sections are available. The Oil-Water Contact has been defined. Laboratory capillary pressure data was used to define the initial water saturations within the pay horizon. The reservoir`s porosity distribution has been enhanced with the assistance of geostatistical software. Three-Dimensional kriging created the spatial distributions of porosity at interwell locations. Artificial intelligence software was utilized to relate core permeability to core porosity, which in turn was applied to the 3-D geostatistical porosity gridding. An Equation-of-State has been developed and refined for upcoming compositional simulation exercises. Options for local grid-refinement in the model are under consideration. These tasks will be completed by mid-1995, prior to initiating the field demonstrations in the second budget period.

"Bricks and mortar" self-assembly approach to graphitic mesoporous carbon nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Fulvio, P. F.; Mayes, R.; Wang, X. Q.; Mahurin, S., M.; Bauer, J. C.; Presser, V.; McDonough, J.; Gogotsi, Y.; Dai, S.

2011-04-20

Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 °C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a “brick-and-mortar” approach to obtain ordered graphitic mesoporous carbon nanocomposites with tunable mesopore sizes below 850 °C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure

OpenAIRE

Yingzhi Li; Qinghua Zhang; Junxian Zhang; Lei Jin; Xin Zhao; Ting Xu

2015-01-01

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific ca...

Numerical approach for enhanced oil recovery with surfactant flooding

Directory of Open Access Journals (Sweden)

Sadegh Keshtkar

2016-03-01

Full Text Available The remained oil in the reservoir after conventional water-flooding processes, forms a dispersed phase in the form of oil drops which is trapped by capillary forces and is almost about 70% of the original oil in the place (OOIP. To reduce oil residual saturation in laboratory experiments and field projects, surfactant flooding is effective via decreasing the interfacial tension mobility ratio between oil and water phases. Estimation of the role of design variables, like chemical concentrations, partition coefficient and injection rate in different performance quantities, considering a heterogeneous and multiphase oil reservoir is a critical stage for optimal design. Increasing demand for oil production from water-flooded reservoirs has caused an increasing interest in surfactant-polymer (SP and alkali-surfactant-polymer (ASP. Modeling minimizes the risk of high cost of chemicals by improving our insight of process. In the present paper, a surfactant compositional flood model for a three-component (water, petroleum and surfactant, two phase (aqueous and oleic system is studied. A homogeneous, two-dimensional, isothermal reservoir with no free gas or alkali is assumed. The governing equations are in three categories: the continuity equations for the transport of each component, Darcy's equation for the transport of each phase and other auxiliary equations. The equations are solved by finite-differences using a procedure implicit in pressure and explicit in saturation. The validation of the model is achieved through comparing the modeling results with CMG simulators and Buckley–Leverett theory. The results of modeling showed good agreement with CMG results, and the comparison with Buckley–Leverett theory is explained according to different assumptions. After validation of the model, in order to investigate sensitivity analysis, the effects of system variables (partition coefficient, surface tension, oil viscosity and surface injection

Analytical approach to phonons and electron-phonon interactions in single-walled zigzag carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Kandemir, B S; Keskin, M [Department of Physics, Faculty of Sciences, Ankara University, 06100 Tandogan, Ankara (Turkey)

2008-08-13

In this paper, exact analytical expressions for the entire phonon spectra in single-walled carbon nanotubes with zigzag geometry are presented by using a new approach, originally developed by Kandemir and Altanhan. This approach is based on the concept of construction of a classical lattice Hamiltonian of single-walled carbon nanotubes, wherein the nearest and next nearest neighbor and bond bending interactions are all included, then its quantization and finally diagonalization of the resulting second quantized Hamiltonian. Furthermore, within this context, explicit analytical expressions for the relevant electron-phonon interaction coefficients are also investigated for single-walled carbon nanotubes having this geometry, by the phonon modulation of the hopping interaction.

Analytical approach to phonons and electron-phonon interactions in single-walled zigzag carbon nanotubes

International Nuclear Information System (INIS)

Kandemir, B S; Keskin, M

2008-01-01

In this paper, exact analytical expressions for the entire phonon spectra in single-walled carbon nanotubes with zigzag geometry are presented by using a new approach, originally developed by Kandemir and Altanhan. This approach is based on the concept of construction of a classical lattice Hamiltonian of single-walled carbon nanotubes, wherein the nearest and next nearest neighbor and bond bending interactions are all included, then its quantization and finally diagonalization of the resulting second quantized Hamiltonian. Furthermore, within this context, explicit analytical expressions for the relevant electron-phonon interaction coefficients are also investigated for single-walled carbon nanotubes having this geometry, by the phonon modulation of the hopping interaction

Bottom-up approach for carbon nanotube interconnects

International Nuclear Information System (INIS)

Li Jun; Ye Qi; Cassell, Alan; Ng, Hou Tee; Stevens, Ramsey; Han Jie; Meyyappan, M.

2003-01-01

We report a bottom-up approach to integrate multiwalled carbon nanotubes (MWNTs) into multilevel interconnects in silicon integrated-circuit manufacturing. MWNTs are grown vertically from patterned catalyst spots using plasma-enhanced chemical vapor deposition. We demonstrate the capability to grow aligned structures ranging from a single tube to forest-like arrays at desired locations. SiO 2 is deposited to encapsulate each nanotube and the substrate, followed by a mechanical polishing process for planarization. MWNTs retain their integrity and demonstrate electrical properties consistent with their original structure

A Novel Approach To Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost

Energy Technology Data Exchange (ETDEWEB)

Michael J. McKelvy; Andrew V. G. Chizmeshya; Kyle Squires; Ray W. Carpenter; Hamdallah Bearat

2006-06-21

Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. Herein, we report our second year progress in exploring a novel approach that offers the potential to substantially enhance carbonation reactivity while bypassing pretreatment activation. As our second year progress is intimately related to our earlier work, the report is presented in that context to provide better overall understanding of the progress made. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly

Carbon nanospheres derived from Lablab purpureus for high performance supercapacitor electrodes: a green approach.

Science.gov (United States)

Ali, Gomaa A M; Divyashree, A; Supriya, S; Chong, Kwok Feng; Ethiraj, Anita S; Reddy, M V; Algarni, H; Hegde, Gurumurthy

2017-10-17

Carbon nanospheres derived from a natural source using a green approach were reported. Lablab purpureus seeds were pyrolyzed at different temperatures to produce carbon nanospheres for supercapacitor electrode materials. The synthesized carbon nanospheres were analyzed using SEM, TEM, FTIR, TGA, Raman spectroscopy, BET and XRD. They were later fabricated into electrodes for cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy testing. The specific capacitances were found to be 300, 265 and 175 F g -1 in 5 M KOH electrolyte for carbon nanospheres synthesized at 800, 700 and 500 °C, respectively. These are on a par with those of prior electrodes made of biologically derived carbon nanospheres but the cycle lives were remarkably higher than those of any previous efforts. The electrodes showed 94% capacitance retention even after 5200 charge/discharge cycles entailing excellent recycling durability. In addition, the practical symmetrical supercapacitor showed good electrochemical behaviour under a potential window up to 1.7 V. This brings us one step closer to fabricating a commercial green electrode which exhibits high performance for supercapacitors. This is also a waste to wealth approach based carbon material for cost effective supercapacitors with high performance for power storage devices.

Constructive Activation of Reservoir-Resident Microbes for Enhanced Oil Recovery

Science.gov (United States)

DeBruyn, R. P.

2017-12-01

Microbial communities living in subsurface oil reservoirs biodegrade oil, producing methane. If this process could create methane within the waterflooded pore spaces of an oilfield, the methane would be expected to remain and occupy pore space, decreasing water relative permeability, diverting water flow, and increasing oil recovery by expanding the swept zone of the waterflood. This approach was tested in an oilfield in northern Montana. Preliminary assessments were made of geochemical conditions and microbiological habitations. Then, a formulation of microbial activators, with composition tailored for the reservoir's conditions, was metered at low rates into the existing injection water system for one year. In the field, the responses observed included improved oil production performance; a slight increase in injection pressure; and increased time needed for tracers to move between injection and producing wells. We interpret these results to confirm that successful stimulation of the microbial community caused more methane to be created within the swept zone of the waterflooded reservoir. When the methane exsolved as water flowed between high-pressure injection and low-pressure production wells, the bubbles occupied pore space, reducing water saturation and relative permeability, and re-directing some water flow to "slower" unswept rock with lower permeability and higher oil saturation. In total, the waterflood's swept zone had been expanded to include previously-unflooded rock. This technology was applied in this field after screening based on careful anaerobic sampling, advanced microbiological analysis, and the ongoing success of its waterflood. No reservoir or geological or geophysical simulation models were employed, and physical modifications to field facilities were minor. This technology of utilizing existing microbial populations for enhanced oil recovery can therefore be considered for deployment into waterfloods where small scale, advanced maturity, or

Application of reservoir characterization and advanced technology to improve recovery and economics in a lower quality shallow shelf carbonate reservoir. End of budget period report, August 3, 1994--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Taylor, A.R.; Hinterlong, G.; Watts, G.; Justice, J.; Brown, K.; Hickman, T.S.

1997-12-01

The Oxy West Welch project is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO{sub 2} injection projects in a lower quality shallow shelf carbonate reservoir. The research and design phase primarily involves advanced reservoir characterization and accelerating the production response. The demonstration phase will implement the reservoir management plan based on an optimum miscible CO{sub 2} flood as designed in the initial phase. During Budget Period 1, work was completed on the CO{sub 2} stimulation treatments and the hydraulic fracture design. Analysis of the CO{sub 2} stimulation treatment provided a methodology for predicting results. The hydraulic fracture treatment proved up both the fracture design approach a and the use of passive seismic for mapping the fracture wing orientation. Although the 3-D seismic interpretation is still being integrated into the geologic model and interpretation of borehole seismic is still underway, the simulator has been enhanced to the point of giving good waterflood history matches. The simulator-forecasted results for an optimal designed miscible CO{sub 2} flood in the demonstration area gave sufficient economics to justify continuation of the project into Budget Period 2.

An approach to computing marginal land use change carbon intensities for bioenergy in policy applications

International Nuclear Information System (INIS)

Wise, Marshall; Hodson, Elke L.; Mignone, Bryan K.; Clarke, Leon; Waldhoff, Stephanie; Luckow, Patrick

2015-01-01

Accurately characterizing the emissions implications of bioenergy is increasingly important to the design of regional and global greenhouse gas mitigation policies. Market-based policies, in particular, often use information about carbon intensity to adjust relative deployment incentives for different energy sources. However, the carbon intensity of bioenergy is difficult to quantify because carbon emissions can occur when land use changes to expand production of bioenergy crops rather than simply when the fuel is consumed as for fossil fuels. Using a long-term, integrated assessment model, this paper develops an approach for computing the carbon intensity of bioenergy production that isolates the marginal impact of increasing production of a specific bioenergy crop in a specific region, taking into account economic competition among land uses. We explore several factors that affect emissions intensity and explain these results in the context of previous studies that use different approaches. Among the factors explored, our results suggest that the carbon intensity of bioenergy production from land use change (LUC) differs by a factor of two depending on the region in which the bioenergy crop is grown in the United States. Assumptions about international land use policies (such as those related to forest protection) and crop yields also significantly impact carbon intensity. Finally, we develop and demonstrate a generalized method for considering the varying time profile of LUC emissions from bioenergy production, taking into account the time path of future carbon prices, the discount rate and the time horizon. When evaluated in the context of power sector applications, we found electricity from bioenergy crops to be less carbon-intensive than conventional coal-fired electricity generation and often less carbon-intensive than natural-gas fired generation. - Highlights: • Modeling methodology for assessing land use change emissions from bioenergy • Use GCAM

Making a commercial carbon fiber cloth having comparable capacitances to carbon nanotubes and graphene in supercapacitors through a "top-down" approach.

Science.gov (United States)

Zhang, Tianchang; Kim, Christine H J; Cheng, Yingwen; Ma, Yanwen; Zhang, Hongbo; Liu, Jie

2015-02-21

A "top-down" and scalable approach for processing carbon fiber cloth (CFC) into flexible and all-carbon electrodes with remarkable areal capacity and cyclic stability was developed. CFC is commercially available in large quantities but its use as an electrode material in supercapacitors is not satisfactory. The approach demonstrated in this work is based on the sequential treatment of CFC with KOH activation and high temperature annealing that can effectively improve its specific surface area to a remarkable 2780 m(2) g(-1) while at the same time achieving a good electrical conductivity of 320 S m(-1) without sacrificing its intrinsic mechanical strength and flexibility. The processed CFC can be directly used as an electrode for supercapacitors without any binders, conductive additives and current collectors while avoiding elaborate electrode processing steps to deliver a specific capacitance of ∼0.5 F cm(-2) and ∼197 F g(-1) with remarkable rate performance and excellent cyclic stability. The properties of these processed CFCs are comparable or better than graphene and carbon nanotube based electrodes. We further demonstrate symmetric solid-state supercapacitors based on these processed CFCs with very good flexibility. This "top-down" and scalable approach can be readily applied to other types of commercially available carbon materials and therefore can have a substantial significance for high performance supercapacitor devices.

Towards an integrated, multiple constraint approach. Assessing the regional carbon balance

International Nuclear Information System (INIS)

Kruijt, B.; Dolman, A.J.; Lloyd, J.; Ehleringer, J.; Raupach, M.; Finnigan, J.

2001-01-01

Full carbon accounting for regions as a whole, considering all fluxes and transports, is ultimately the only real hope if we are to manage global CO2 emissions. Many methods exist to estimate parts of the carbon budget, but none is yet available to measure carbon fluxes directly at regional scales. Atmospheric Boundary-Layer budgeting methods do have this potential. In the winter of 2000, an international workshop was held in Gubbio, Italy, to discuss ways to advance from the pilot experiments that have been carried out on these methods. First, the meeting helped to advance the methodology and clarify its objectives, requirements and merits. But more importantly, the outcome of the meeting was that atmospheric budget methods should be part of an integrative approach, in which data and model results of very different kinds and from very different scales all provide constraints for estimating the net carbon exchange of a region. Several international projects are now operating to achieve this goal

An approach to include soil carbon changes in life cycle assessments

DEFF Research Database (Denmark)

Petersen, Bjorn Molt; Knudsen, Marie Trydeman; Hermansen, John Erik

2013-01-01

to estimate carbon sequestration to be included in LCA is suggested and applied to two examples where the inclusion of carbon sequestration is especially relevant: 1) Bioenergy: removal of straw from a Danish soil for energy purposes and 2) Organic versus conventional farming: comparative study of soybean...... comparable to the IPCC 2006 tier I approach in a time perspective of 20 year, where after the suggested methodology showed a continued soil carbon change toward a new steady state. The suggested method estimated a carbon sequestration for the first example when storing straw in the soil instead of using...... it for bioenergy of 54, 97 and 213 kg C t(-1) straw C in a 200, 100 and 20 years perspective, respectively. For the conversion from conventional to organic soybean production, a difference of 32, 60 or 143 kg soil C ha(-1) yr(-1) in a 200,100 or 20 years perspective, respectively was found. The study indicated...

An integrated approach to geological disposal of UK wastes containing carbon-14

International Nuclear Information System (INIS)

Vines, Sarah; Lever, David

2013-01-01

Carbon-14 is a key radionuclide in the assessment of the safety of a geological disposal facility for radioactive waste because of the calculated assessment of the radiological consequences of gaseous carbon-14 bearing species [i]. It may be that such calculations are based on overly conservative assumptions and that better understanding could lead to considerably reduced assessment of the radiological consequences from these wastes. Alternatively, it may be possible to mitigate the impact of these wastes through alternative treatment, packaging or design options. The Radioactive Waste Management Directorate of the UK's Nuclear Decommissioning Authority (NDA RWMD) has established an integrated project team in which the partners are working together to develop a holistic approach to carbon-14 management in the disposal system [ii]. For a waste stream containing carbon-14 to be an issue: There must be a significant inventory of carbon-14 in the waste stream; and That waste stream has to generate carbon-14 bearing gas; and a bulk gas phase has to entrain the carbon-14 bearing gas: and these gases must migrate through the engineered barriers in significant quantities; and these gases must migrate through the overlying geological environment (either as a distinct gas phase or as dissolved gas); and these gases must interact with materials in the biosphere (i.e. plants) in a manner that leads to significant doses and risks to exposed groups or potentially exposed groups. The project team has developed and used this 'and' approach to structure and prioritise the technical work and break the problem down in a manageable way. We have also used it to develop our approach to considering alternative treatment, packaging and design options. For example, it may be possible to pre-treat some wastes to remove some of the inventory or to segregate other wastes so that they are removed from any bulk gas phase which might facilitate migration through the geosphere

An integrated approach to geological disposal of UK wastes containing carbon-14

Energy Technology Data Exchange (ETDEWEB)

Vines, Sarah [Nuclear Decommissioning Authority, Harwell, Oxfordshire (United Kingdom); Lever, David [AMEC, Harwell, Oxfordshire (United Kingdom)

2013-07-01

Carbon-14 is a key radionuclide in the assessment of the safety of a geological disposal facility for radioactive waste because of the calculated assessment of the radiological consequences of gaseous carbon-14 bearing species [i]. It may be that such calculations are based on overly conservative assumptions and that better understanding could lead to considerably reduced assessment of the radiological consequences from these wastes. Alternatively, it may be possible to mitigate the impact of these wastes through alternative treatment, packaging or design options. The Radioactive Waste Management Directorate of the UK's Nuclear Decommissioning Authority (NDA RWMD) has established an integrated project team in which the partners are working together to develop a holistic approach to carbon-14 management in the disposal system [ii]. For a waste stream containing carbon-14 to be an issue: There must be a significant inventory of carbon-14 in the waste stream; and That waste stream has to generate carbon-14 bearing gas; and a bulk gas phase has to entrain the carbon-14 bearing gas: and these gases must migrate through the engineered barriers in significant quantities; and these gases must migrate through the overlying geological environment (either as a distinct gas phase or as dissolved gas); and these gases must interact with materials in the biosphere (i.e. plants) in a manner that leads to significant doses and risks to exposed groups or potentially exposed groups. The project team has developed and used this 'and' approach to structure and prioritise the technical work and break the problem down in a manageable way. We have also used it to develop our approach to considering alternative treatment, packaging and design options. For example, it may be possible to pre-treat some wastes to remove some of the inventory or to segregate other wastes so that they are removed from any bulk gas phase which might facilitate migration through the geosphere

Forecasting approach of electrochemical valorisation of CO2 in alkali molten carbonates

International Nuclear Information System (INIS)

Chery, Deborah

2015-01-01

Carbon Dioxide is a greenhouse which can be valorised by means of electrochemical valorisation into carbon monoxide. The main goals of the thesis consist in the theoretical determination of the conductive conditions leading to this electrochemical valorisation in alkali molten carbonates along with the study of the feasibility of this electrochemical reduction in binary and ternary eutectics under experimental condition. CO 2 solubility has been determined by manometric measure and increase along with the temperature. CO 2 electrochemical experimental feasibility into CO in eutectics on gold plate electrode and graphite carbon has been proved by cyclic volt-amperometry for temperatures exceeding 550 C, without gold plate electrode pretreatment and with gold plate pretreatment by an pre-electrolysis at potential slightly negative as the CO 2 reduction potential. A global approach of reactional mechanisms implied in CO 2 reduction is proposed. (author)

Examining carbon emissions economic growth nexus for India: A multivariate cointegration approach

International Nuclear Information System (INIS)

Ghosh, Sajal

2010-01-01

The study probes cointegration and causality between carbon emissions and economic growth for India using ARDL bounds testing approach complemented by Johansen-Juselius maximum likelihood procedure in a multivariate framework by incorporating energy supply, investment and employment for time span 1971-2006. The study fails to establish long-run equilibrium relationship and long term causality between carbon emissions and economic growth; however, there exists a bi-directional short-run causality between the two. Hence, in the short-run, any effort to reduce carbon emissions could lead to a fall in the national income. This study also establishes unidirectional short-run causality running from economic growth to energy supply and energy supply to carbon emissions. The absence of causality running from energy supply to economic growth implies that in India, energy conservation and energy efficiency measures can be implemented to minimize the wastage of energy across value chain. Such measures would narrow energy demand-supply gap. Absence of long-run causality between carbon emissions and economic growth implies that in the long-run, focus should be given on harnessing energy from clean sources to curb carbon emissions, which would not affect the country's economic growth.

Urbanization and carbon dioxide emissions in Singapore: evidence from the ARDL approach.

Science.gov (United States)

Ali, Hamisu Sadi; Abdul-Rahim, A S; Ribadu, Mohammed Bashir

2017-01-01

The main aim of this article is to examine empirically the impact of urbanization on carbon dioxide emissions in Singapore from 1970 to 2015. The autoregressive distributed lags (ARDL) approach is applied within the analysis. The main finding reveals a negative and significant impact of urbanization on carbon emissions in Singapore, which means that urban development in Singapore is not a barrier to the improvement of environmental quality. Thus, urbanization enhances environmental quality by reducing carbon emissions in the sample country. The result also highlighted that economic growth has a positive and significant impact on carbon emissions, which suggests that economic growth reduces environmental quality through its direct effect of increasing carbon emissions in the country. Despite the high level of urbanization in Singapore, which shows that 100 % of the populace is living in the urban center, it does not lead to more environmental degradation. Hence, urbanization will not be considered an obstacle when initiating policies that will be used to reduce environmental degradation in the country. Policy makers should consider the country's level of economic growth instead of urbanization when formulating policies to reduce environmental degradation, due to its direct impact on increasing carbon dioxide emissions.

The UK transport carbon model: An integrated life cycle approach to explore low carbon futures

International Nuclear Information System (INIS)

Brand, Christian; Tran, Martino; Anable, Jillian

2012-01-01

Current debate focuses on the need for the transport sector to contribute to more ambitious carbon emission reduction targets. In the UK, various macro-economic and energy system wide, top-down models are used to explore the potential for energy demand and carbon emissions reduction in the transport sector. These models can lack the bottom-up, sectoral detail needed to simulate the effects of integrated demand and supply-side policy strategies to reduce emissions. Bridging the gap between short-term forecasting and long-term scenario “models”, this paper introduces a newly developed strategic transport, energy, emissions and environmental impacts model, the UK Transport Carbon Model (UKTCM). The UKTCM covers the range of transport–energy–environment issues from socio-economic and policy influences on energy demand reduction through to life cycle carbon emissions and external costs. The model is demonstrated in this paper by presenting the results of three single policies and one policy package scenario. Limitations of the model are also discussed. Developed under the auspices of the UK Energy Research Centre (UKERC) the UKTCM can be used to develop transport policy scenarios that explore the full range of technological, fiscal, regulatory and behavioural change policy interventions to meet UK climate change and energy security goals. - Research highlights: ►New strategic transport, energy, emissions and environmental impacts model. ►Tool to develop and analyse full consequences of multiple scenarios of transport policy packages. ►Novel approach to modelling demand for new vehicles by market and technology. ►Model available for use by research community via http://www.ukerc.ac.uk/support/tiki-index.php?page=UK+Transport+Carbon+Model.

Carbonate rock depositional models: A microfacies approach

Energy Technology Data Exchange (ETDEWEB)

Carozzi, A.V.

1988-01-01

Carbonate rocks contain more than 50% by weight carbonate minerals such as calcite, dolomite, and siderite. Understanding how these rocks form can lead to more efficient methods of petroleum exploration. Micofacies analysis techniques can be used as a method of predicting models of sedimentation for carbonate rocks. Micofacies in carbonate rocks can be seen clearly only in thin sections under a microscope. This section analysis of carbonate rocks is a tool that can be used to understand depositional environments, diagenetic evolution of carbonate rocks, and the formation of porosity and permeability in carbonate rocks. The use of micofacies analysis techniques is applied to understanding the origin and formation of carbonate ramps, carbonate platforms, and carbonate slopes and basins. This book will be of interest to students and professionals concerned with the disciplines of sedimentary petrology, sedimentology, petroleum geology, and palentology.

Quantifying black carbon light absorption enhancement with a novel statistical approach

Science.gov (United States)

Wu, Cheng; Wu, Dui; Zhen Yu, Jian

2018-01-01

Black carbon (BC) particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, Eabs, was quantified using a 1-year measurement of mass absorption efficiency (MAE) in the Pearl River Delta region (PRD). A new approach for calculating primary MAE (MAEp), the key for Eabs estimation, is demonstrated using the minimum R squared (MRS) method, exploring the inherent source independency between BC and its coating materials. A unique feature of Eabs estimation with the MRS approach is its insensitivity to systematic biases in elemental carbon (EC) and σabs measurements. The annual average Eabs550 is found to be 1.50 ± 0.48 (±1 SD) in the PRD region, exhibiting a clear seasonal pattern with higher values in summer and lower in winter. Elevated Eabs in the summertime is likely associated with aged air masses, predominantly of marine origin, along with long-range transport of biomass-burning-influenced air masses from Southeast Asia. Core-shell Mie simulations along with measured Eabs and absorption Ångström exponent (AAE) constraints suggest that in the PRD, the coating materials are unlikely to be dominated by brown carbon and the coating thickness is higher in the rainy season than in the dry season.

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure.

Science.gov (United States)

Li, Yingzhi; Zhang, Qinghua; Zhang, Junxian; Jin, Lei; Zhao, Xin; Xu, Ting

2015-09-23

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific capacitance of 204 F g(-1) at 1 A g(-1); good rate capability, as indicated by the residual initial capacitance of 85.5% at 10 A g(-1); and a long cycle life. These performance characteristics are attributed to the outstanding hierarchical structures of the electrode material. Appropriate carbonization conditions enable the bio-carbon materials to inherit the inherent hierarchical texture of the original biomass, thereby facilitating effective channels for fast ion transfer. The macropores and mesopores that result from chemical activation significantly increase the specific surface area and also play the role of temporary ion-buffering reservoirs, further shortening the ionic diffusion distance.

Southwest Regional Partnership on Carbon Sequestration Phase II

Energy Technology Data Exchange (ETDEWEB)

James Rutledge

2011-02-01

The Southwest Regional Partnership (SWP) on Carbon Sequestration designed and deployed a medium-scale field pilot test of geologic carbon dioxide (CO2) sequestration in the Aneth oil field. Greater Aneth oil field, Utah's largest oil producer, was discovered in 1956 and has produced over 455 million barrels of oil (72 million m3). Located in the Paradox Basin of southeastern Utah, Greater Aneth is a stratigraphic trap producing from the Pennsylvanian Paradox Formation. Because it represents an archetype oil field of the western U.S., Greater Aneth was selected as one of three geologic pilots to demonstrate combined enhanced oil recovery (EOR) and CO2 sequestration under the auspices of the SWP on Carbon Sequestration, sponsored by the U.S. Department of Energy. The pilot demonstration focuced on the western portion of the Aneth Unit as this area of the field was converted from waterflood production to CO2 EOR starting in late 2007. The Aneth Unit is in the northwestern part of the field and has produced 149 million barrels (24 million m3) of the estimated 450 million barrels (71.5 million m3) of the original oil in place - a 33% recovery rate. The large amount of remaining oil makes the Aneth Unit ideal to demonstrate both CO2 storage capacity and EOR by CO2 flooding. This report summarizes the geologic characterization research, the various field monitoring tests, and the development of a geologic model and numerical simulations conducted for the Aneth demonstration project. The Utah Geological Survey (UGS), with contributions from other Partners, evaluated how the surface and subsurface geology of the Aneth Unit demonstration site will affect sequestration operations and engineering strategies. The UGS-research for the project are summarized in Chapters 1 through 7, and includes (1) mapping the surface geology including stratigraphy, faulting, fractures, and deformation bands, (2) describing the local Jurassic and Cretaceous stratigraphy, (3) mapping the

An Indicator Approach to Assessing Benefits of Carbon Sequestration and Other Ecosystem Services

Science.gov (United States)

Dale, V. H.; Kline, K. L.; Parish, E. S.

2017-12-01

While geoengineering offers one approach to carbon management, another tactic is providing land owners and managers with incentives to more efficiently and consistently increase carbon stocks and storage in soils and above ground. Growing bioenergy crops entails such an option. Landscape design can help identify where different strategies best fit into the larger framework of resource management to achieve desired stakeholder objectives. Our research goal is to develop means to assess management options and identify those that offer the highest degree of sustainability as measured by the provision to society of specific economic, environmental and social services with the least costs. Oak Ridge National Laboratory (ORNL) has worked with the US Department of Energy to develop an approach for assessing progress toward better management to improve sustainability. This approach involves six steps with decisions made at each step. First the scope of the assessment is established based on the particular context and options. Next indicators that pertain to the objective are selected and prioritized. Then, baselines and targets are determined for each indicator. Fourth, indicator values are measured, collected, and evaluated. Once the values are in hand, trends and tradeoffs in the indicator set are analyzed. The final step seeks to define and deploy good practices for the activity. ORNL's proposed checklist of environmental and socioeconomic indicators includes greenhouse gases and soil quality (including carbon) and emphasizes that changes in carbon stocks must be viewed in terms of their effects on other indicators, such as those for water quality and quantity, biodiversity, air quality, and productivity as well as on socioeconomic costs and benefits. The framework developed to select and evaluate indicators and assess progress toward sustainability goals is being encapsulated into a visualization tool. Visualization will inform stakeholders about potential effects of

Low carbon and clean energy scenarios for India: Analysis of targets approach

International Nuclear Information System (INIS)

Shukla, Priyadarshi R.; Chaturvedi, Vaibhav

2012-01-01

Low carbon energy technologies are of increasing importance to India for reducing emissions and diversifying its energy supply mix. Using GCAM, an integrated assessment model, this paper analyzes a targets approach for pushing solar, wind, and nuclear technologies in the Indian electricity generation sector from 2005 to 2095. Targets for these technologies have been constructed on the basis of Indian government documents, policy announcements, and expert opinions. Different targets have been set for the reference scenario and the carbon price scenario. In the reference scenario, wind and nuclear technologies exceed respective targets in the long run without any subsidy push, while solar energy requires subsidy push throughout the century in order to meet its high targets. In the short run, nuclear energy also requires significant subsidy, including a much higher initial subsidy relative to solar power, which is a result of its higher targets. Under a carbon price scenario, the carbon price drives the penetration of these technologies. Still, subsidy is required — especially in the short run when the carbon price is low. We also found that pushing solar, wind, and nuclear technologies leads to a decrease in share of CCS under the carbon price scenario and biomass under both the reference and carbon price scenarios. This is because low carbon technologies compete among themselves and substitute each other, thereby enhancing the need for subsidy or carbon price, highlighting that proposed targets are not set at efficient levels. In light of contemporary debate on external costs of nuclear energy, we also assess the sensitivity of the results to nuclear technology cost. We find that higher cost significantly decreases the share of nuclear power under both the reference and carbon price scenarios.

Carbon Dissolution Using Waste Biomass—A Sustainable Approach for Iron-Carbon Alloy Production

Directory of Open Access Journals (Sweden)

Irshad Mansuri

2018-04-01

Full Text Available This paper details the characterisation of char obtained by high-temperature pyrolysis of waste macadamia shell biomass and its application as carbon source in iron-carbon alloy production. The obtained char was characterised by ultimate and proximate analysis, X-ray diffraction (XRD, Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR, X-ray photon spectroscopy (XPS, Brunauer-Emmett-Teller (BET surface area via N2 isothermal adsorption and scanning electron microscopy (SEM. The results indicated that obtained char is less porous, low in ash content, and high in carbon content. Investigation of iron-carbon alloy formation through carbon dissolution at 1550 °C was carried out using sessile drop method by using obtained char as a carbon source. Rapid carbon pickup by iron was observed during first two minutes of contact and reached a saturation value of ~5.18 wt % of carbon after 30 min. The carbon dissolution rate using macadamia char as a source of carbon was comparatively higher using than other carbonaceous materials such as metallurgical coke, coal chars, and waste compact discs, due to its high percentage of carbon and low ash content. This research shows that macadamia shell waste, which has a low content of ash, is a valuable supplementary carbon source for iron-carbon alloy industries.

A hybrid modelling approach to develop scenarios for China's carbon dioxide emissions to 2050

International Nuclear Information System (INIS)

Gambhir, Ajay; Schulz, Niels; Napp, Tamaryn; Tong, Danlu; Munuera, Luis; Faist, Mark; Riahi, Keywan

2013-01-01

This paper describes a hybrid modelling approach to assess the future development of China's energy system, for both a “hypothetical counterfactual baseline” (HCB) scenario and low carbon (“abatement”) scenarios. The approach combines a technology-rich integrated assessment model (MESSAGE) of China's energy system with a set of sector-specific, bottom-up, energy demand models for the transport, buildings and industrial sectors developed by the Grantham Institute for Climate Change at Imperial College London. By exploring technology-specific solutions in all major sectors of the Chinese economy, we find that a combination of measures, underpinned by low-carbon power options based on a mix of renewables, nuclear and carbon capture and storage, would fundamentally transform the Chinese energy system, when combined with increasing electrification of demand-side sectors. Energy efficiency options in these demand sectors are also important. - Highlights: • Combining energy supply and demand models reveals low-carbon technology choices across China's economy. • China could reduce its CO 2 emissions to close to 3 Gt in 2050, costing around 2% of GDP. • Decarbonising the power sector underpins the energy system transformation. • Electrification of industrial processes, building heating and transport is required. • Energy efficiency across the demand side is also important

Temporal dynamics of soil organic carbon after land-use change in the temperate zone – carbon response functions as a model approach

DEFF Research Database (Denmark)

Poeplau, Christopher; Don, Axel; Vesterdal, Lars

2011-01-01

Land-use change (LUC) is a major driving factor for the balance of soil organic carbon (SOC) stocks and the global carbon cycle. The temporal dynamic of SOC after LUC is especially important in temperate systems with a long reaction time. On the basis of 95 compiled studies covering 322 sites...... approach, the developed CRFs provide an easily applicable tool to estimate SOC stock changes after LUC to improve greenhouse gas reporting in the framework of UNFCCC....

A novel and facile synthesis approach for a porous carbon/graphene composite for high-performance supercapacitors.

Science.gov (United States)

Liu, Ting; Zhang, Xuesha; Liu, Kang; Liu, Yanyan; Liu, Mengjie; Wu, Wenyu; Gu, Yu; Zhang, Ruijun

2018-03-02

We propose a novel and facile synthesis approach to a porous carbon/graphene composite. Graphene is obtained from room-temperature expanded graphite (RTEG), not involving the use of graphite oxide (GO). Porous carbon is acquired by carbonization and KOH-activation of polyvinylpyrrolidone (PVP), which is used to exfoliate RTEG into graphene and inhibit the restacking of the resultant graphene in the present work. The prepared porous carbon/graphene composite has a high specific surface area (SSA) (3008 m 2 g -1 ) and a hierarchical micro- and meso- pore structure (dominant pores in the range of 1-5 nm). Electrochemical measurement demonstrates that the as-prepared porous carbon/graphene composite can deliver an outstanding specific capacitance of up to 340 F g -1 at 5 mV s -1 in 6 M KOH electrolyte. This specific capacitance is among the highest reported so far for porous carbon/graphene materials. Moreover, the prepared composite as an electrode material also exhibits excellent cycling stability (94.4% capacitance retention over 10 000 cycles). The as-fabricated symmetrical supercapacitor exhibits a high energy density of 10.9 W h kg -1 (based on total mass of electrode materials) and an outstanding energy density retention, even at high power density. Compared with conventional preparation routes for porous carbon/graphene composites, the present approach is significantly simple, convenient and cost-effective, which will make it more competent in the development of electrode materials for high-performance supercapacitors.

LIDAR-based urban metabolism approach to neighbourhood scale energy and carbon emissions modelling

Energy Technology Data Exchange (ETDEWEB)

Christen, A. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Geography; Coops, N. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Forest Sciences; Canada Research Chairs, Ottawa, ON (Canada); Kellet, R. [British Columbia Univ., Vancouver, BC (Canada). School of Architecture and Landscape Architecture

2010-07-01

A remote sensing technology was used to model neighbourhood scale energy and carbon emissions in a case study set in Vancouver, British Columbia (BC). The study was used to compile and aggregate atmospheric carbon flux, urban form, and energy and emissions data in a replicable neighbourhood-scale approach. The study illustrated methods of integrating diverse emission and uptake processes on a range of scales and resolutions, and benchmarked comparisons of modelled estimates with measured energy consumption data obtained over a 2-year period from a research tower located in the study area. The study evaluated carbon imports, carbon exports and sequestration, and relevant emissions processes. Fossil fuel emissions produced in the neighbourhood were also estimated. The study demonstrated that remote sensing technologies such as LIDAR and multispectral satellite imagery can be an effective means of generating and extracting urban form and land cover data at fine scales. Data from the study were used to develop several emissions reduction and energy conservation scenarios. 6 refs.

A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback: The PCN Incubation-Panarctic Thermal (PInc-PanTher) Scaling Approach

Science.gov (United States)

Koven, C. D.; Schuur, E.; Schaedel, C.; Bohn, T. J.; Burke, E.; Chen, G.; Chen, X.; Ciais, P.; Grosse, G.; Harden, J. W.; Hayes, D. J.; Hugelius, G.; Jafarov, E. E.; Krinner, G.; Kuhry, P.; Lawrence, D. M.; MacDougall, A.; Marchenko, S. S.; McGuire, A. D.; Natali, S.; Nicolsky, D.; Olefeldt, D.; Peng, S.; Romanovsky, V. E.; Schaefer, K. M.; Strauss, J.; Treat, C. C.; Turetsky, M. R.

2015-12-01

We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a 3-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100.

Evaluating the Influence of Pore Architecture and Initial Saturation on Wettability and Relative Permeability in Heterogeneous, Shallow-Shelf Carbonates

Energy Technology Data Exchange (ETDEWEB)

Byrnes, Alan P.; Bhattacharya, Saibal; Victorine, John; Stalder, Ken

2007-09-30

Thin (3-40 ft thick), heterogeneous, limestone and dolomite reservoirs, deposited in shallow-shelf environments, represent a significant fraction of the reservoirs in the U.S. midcontinent and worldwide. In Kansas, reservoirs of the Arbuckle, Mississippian, and Lansing-Kansas City formations account for over 73% of the 6.3 BBO cumulative oil produced over the last century. For these reservoirs basic petrophysical properties (e.g., porosity, absolute permeability, capillary pressure, residual oil saturation to waterflood, resistivity, and relative permeability) vary significantly horizontally, vertically, and with scale of measurement. Many of these reservoirs produce from structures of less than 30-60 ft, and being located in the capillary pressure transition zone, exhibit vertically variable initial saturations and relative permeability properties. Rather than being simpler to model because of their small size, these reservoirs challenge characterization and simulation methodology and illustrate issues that are less apparent in larger reservoirs where transition zone effects are minor and most of the reservoir is at saturations near S{sub wirr}. These issues are further augmented by the presence of variable moldic porosity and possible intermediate to mixed wettability and the influence of these on capillary pressure and relative permeability. Understanding how capillary-pressure properties change with rock lithology and, in turn, within transition zones, and how relative permeability and residual oil saturation to waterflood change through the transition zone is critical to successful reservoir management and as advanced waterflood and improved and enhanced recovery methods are planned and implemented. Major aspects of the proposed study involve a series of tasks to measure data to reveal the nature of how wettability and drainage and imbibition oil-water relative permeability change with pore architecture and initial water saturation. Focus is placed on

Carbon footprint of patient journeys through primary care: a mixed methods approach.

Science.gov (United States)

Andrews, Elizabeth; Pearson, David; Kelly, Charlotte; Stroud, Laura; Rivas Perez, Martin

2013-09-01

The NHS has a target of cutting its carbon dioxide (CO2) emissions by 80% below 1990 levels by 2050. Travel comprises 17% of the NHS carbon footprint. This carbon footprint represents the total CO2 emissions caused directly or indirectly by the NHS. Patient journeys have previously been planned largely without regard to the environmental impact. The potential contribution of 'avoidable' journeys in primary care is significant. To investigate the carbon footprint of patients travelling to and from a general practice surgery, the issues involved, and potential solutions for reducing patient travel. A mixed methods study in a medium-sized practice in Yorkshire. During March 2012, 306 patients completed a travel survey. GIS maps of patients' travel (modes and distances) were produced. Two focus groups (12 clinical and 13 non-clinical staff) were recorded, transcribed, and analysed using a thematic framework approach. The majority (61%) of patient journeys to and from the surgery were made by car or taxi; main reasons cited were 'convenience', 'time saving', and 'no alternative' for accessing the surgery. Using distances calculated via ArcGIS, the annual estimated CO2 equivalent carbon emissions for the practice totalled approximately 63 tonnes. Predominant themes from interviews related to issues with systems for booking appointments and repeat prescriptions; alternative travel modes; delivering health care; and solutions to reducing travel. The modes and distances of patient travel can be accurately determined and allow appropriate carbon emission calculations for GP practices. Although challenging, there is scope for identifying potential solutions (for example, modifying administration systems and promoting walking) to reduce 'avoidable' journeys and cut carbon emissions while maintaining access to health care.

Quantifying black carbon light absorption enhancement with a novel statistical approach

Directory of Open Access Journals (Sweden)

C. Wu

2018-01-01

Full Text Available Black carbon (BC particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, Eabs, was quantified using a 1-year measurement of mass absorption efficiency (MAE in the Pearl River Delta region (PRD. A new approach for calculating primary MAE (MAEp, the key for Eabs estimation, is demonstrated using the minimum R squared (MRS method, exploring the inherent source independency between BC and its coating materials. A unique feature of Eabs estimation with the MRS approach is its insensitivity to systematic biases in elemental carbon (EC and σabs measurements. The annual average Eabs550 is found to be 1.50 ± 0.48 (±1 SD in the PRD region, exhibiting a clear seasonal pattern with higher values in summer and lower in winter. Elevated Eabs in the summertime is likely associated with aged air masses, predominantly of marine origin, along with long-range transport of biomass-burning-influenced air masses from Southeast Asia. Core–shell Mie simulations along with measured Eabs and absorption Ångström exponent (AAE constraints suggest that in the PRD, the coating materials are unlikely to be dominated by brown carbon and the coating thickness is higher in the rainy season than in the dry season.

Causal nexus between energy consumption and carbon dioxide emission for Malaysia using maximum entropy bootstrap approach.

Science.gov (United States)

Gul, Sehrish; Zou, Xiang; Hassan, Che Hashim; Azam, Muhammad; Zaman, Khalid

2015-12-01

This study investigates the relationship between energy consumption and carbon dioxide emission in the causal framework, as the direction of causality remains has a significant policy implication for developed and developing countries. The study employed maximum entropy bootstrap (Meboot) approach to examine the causal nexus between energy consumption and carbon dioxide emission using bivariate as well as multivariate framework for Malaysia, over a period of 1975-2013. This is a unified approach without requiring the use of conventional techniques based on asymptotical theory such as testing for possible unit root and cointegration. In addition, it can be applied in the presence of non-stationary of any type including structural breaks without any type of data transformation to achieve stationary. Thus, it provides more reliable and robust inferences which are insensitive to time span as well as lag length used. The empirical results show that there is a unidirectional causality running from energy consumption to carbon emission both in the bivariate model and multivariate framework, while controlling for broad money supply and population density. The results indicate that Malaysia is an energy-dependent country and hence energy is stimulus to carbon emissions.

Charge Modulation in Graphitic Carbon Nitride as a Switchable Approach to High-Capacity Hydrogen Storage.

Science.gov (United States)

Tan, Xin; Kou, Liangzhi; Tahini, Hassan A; Smith, Sean C

2015-11-01

Electrical charging of graphitic carbon nitride nanosheets (g-C4 N3 and g-C3 N4 ) is proposed as a strategy for high-capacity and electrocatalytically switchable hydrogen storage. Using first-principle calculations, we found that the adsorption energy of H2 molecules on graphitic carbon nitride nanosheets is dramatically enhanced by injecting extra electrons into the adsorbent. At full hydrogen coverage, the negatively charged graphitic carbon nitride achieves storage capacities up to 6-7 wt %. In contrast to other hydrogen storage approaches, the storage/release occurs spontaneously once extra electrons are introduced or removed, and these processes can be simply controlled by switching on/off the charging voltage. Therefore, this approach promises both facile reversibility and tunable kinetics without the need of specific catalysts. Importantly, g-C4 N3 has good electrical conductivity and high electron mobility, which can be a very good candidate for electron injection/release. These predictions may prove to be instrumental in searching for a new class of high-capacity hydrogen storage materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback.

Science.gov (United States)

Koven, C D; Schuur, E A G; Schädel, C; Bohn, T J; Burke, E J; Chen, G; Chen, X; Ciais, P; Grosse, G; Harden, J W; Hayes, D J; Hugelius, G; Jafarov, E E; Krinner, G; Kuhry, P; Lawrence, D M; MacDougall, A H; Marchenko, S S; McGuire, A D; Natali, S M; Nicolsky, D J; Olefeldt, D; Peng, S; Romanovsky, V E; Schaefer, K M; Strauss, J; Treat, C C; Turetsky, M

2015-11-13

We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a three-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100. Under a medium warming scenario (RCP4.5), the approach projects permafrost soil C losses of 12.2-33.4 Pg C; under a high warming scenario (RCP8.5), the approach projects C losses of 27.9-112.6 Pg C. Projected C losses are roughly linearly proportional to global temperature changes across the two scenarios. These results indicate a global sensitivity of frozen soil C to climate change (γ sensitivity) of -14 to -19 Pg C °C(-1) on a 100 year time scale. For CH4 emissions, our approach assumes a fixed saturated area and that increases in CH4 emissions are related to increased heterotrophic respiration in anoxic soil, yielding CH4 emission increases of 7% and 35% for the RCP4.5 and RCP8.5 scenarios, respectively, which add an additional greenhouse gas forcing of approximately 10-18%. The simplified approach

A Novel Approach to Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost

Energy Technology Data Exchange (ETDEWEB)

Andrew V. G. Chizmeshya; Michael J. McKelvy; Kyle Squires; Ray W. Carpenter; Hamdallah Bearat

2007-06-21

Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly-stirred/circulating carbonation. We are exploring the mechanisms that govern carbonation reactivity and the impact that (1) modeling/controlling the slurry fluid-flow conditions, (2) varying the aqueous ion species/size and concentration (e.g., Li+, Na+, K+, Rb+, Cl-, HCO{sub 3}{sup -}), and (3) incorporating select sonication offer to enhance exfoliation and carbonation. Thus

Towards self-assembled devices, a carbon nanotube approach

OpenAIRE

Del Rio Castillo, Antonio Esau

2012-01-01

2010/2011 In the last decade the nanostructured carbon materials, especially single walled carbon nanotubes (SWNTs), had emerged as probable substitutes for Silicon in the next generation of electronic devices. This is due to their unique physic and chemical properties. Likewise, scientists all around the world have made a huge effort to introduce carbon materials into the market. Despite this effort, commercial application for carbon nanotubes in electronic devices has not yet been achiev...

Equivalence among three alternative approaches to estimating live tree carbon stocks in the eastern United States

Science.gov (United States)

Coeli M. Hoover; James E. Smith

2017-01-01

Assessments of forest carbon are available via multiple alternate tools or applications and are in use to address various regulatory and reporting requirements. The various approaches to making such estimates may or may not be entirely comparable. Knowing how the estimates produced by some commonly used approaches vary across forest types and regions allows users of...

Data-based perfect-deficit approach to understanding climate extremes and forest carbon assimilation capacity

International Nuclear Information System (INIS)

Wei, Suhua; Yi, Chuixiang; Hendrey, George; Eaton, Timothy; Rustic, Gerald; Wang, Shaoqiang; Liu, Heping; Krakauer, Nir Y; Wang, Weiguo; Desai, Ankur R; Montagnani, Leonardo; Tha Paw U, Kyaw; Falk, Matthias; Black, Andrew; Bernhofer, Christian; Grünwald, Thomas; Laurila, Tuomas; Cescatti, Alessandro; Moors, Eddy

2014-01-01

Several lines of evidence suggest that the warming climate plays a vital role in driving certain types of extreme weather. The impact of warming and of extreme weather on forest carbon assimilation capacity is poorly known. Filling this knowledge gap is critical towards understanding the amount of carbon that forests can hold. Here, we used a perfect-deficit approach to identify forest canopy photosynthetic capacity (CPC) deficits and analyze how they correlate to climate extremes, based on observational data measured by the eddy covariance method at 27 forest sites over 146 site-years. We found that droughts severely affect the carbon assimilation capacities of evergreen broadleaf forest (EBF) and deciduous broadleaf forest. The carbon assimilation capacities of Mediterranean forests were highly sensitive to climate extremes, while marine forest climates tended to be insensitive to climate extremes. Our estimates suggest an average global reduction of forest CPC due to unfavorable climate extremes of 6.3 Pg C (∼5.2% of global gross primary production) per growing season over 2001–2010, with EBFs contributing 52% of the total reduction

A Fuzzy-Grey Multicriteria Decision Making Approach for Green Supplier Selection in Low-Carbon Supply Chain

Directory of Open Access Journals (Sweden)

Qinghua Pang

2017-01-01

Full Text Available Due to the increasing awareness of global warming and environmental protection, many practitioners and researchers have paid much attention to the low-carbon supply chain management in recent years. Green supplier selection is one of the most critical activities in the low-carbon supply chain management, so it is important to establish the comprehensive criteria and develop a method for green supplier selection in low-carbon supply chain. The paper proposes a fuzz-grey multicriteria decision making approach to deal with these problems. First, the paper establishes 4 main criteria and 22 subcriteria for green supplier selection. Then, a method integrating fuzzy set theory and grey relational analysis is proposed. It uses the membership function of normal distribution to compare each supplier and uses grey relation analysis to calculate the weight of each criterion and improves fuzzy comprehensive evaluation. The proposed method can make the localization of individual green supplier more objectively and more accurately in the same trade. Finally, a case study in the steel industry is presented to demonstrate the effectiveness of the proposed approach.

Tunable Polarity Carbon Fibers, a Holistic Approach to Environmental Protection.

Science.gov (United States)

García-Valverde, M Teresa; Ledesma-Escobar, Carlos A; Lucena, Rafael; Cárdenas, Soledad

2018-04-27

The pollution of environmental resources is an issue of social concern worldwide. Chemistry is essential for the design of decontamination strategies and analytical approaches to detect and monitor the contamination. Sorptive materials are usually required in both approaches and green synthesis should be used to minimize their own environmental impact. Carbon fibers (CFs) obtained by the pyrolysis of natural cellulose-rich materials fulfill these requirements. In this article, thirty CFs obtained under different conditions are chemically characterized and their sorption ability towards selected pollutants, covering a wide range of polarity, is evaluated. This study provides more profound knowledge related to the polarity of these materials, their interactions with chemical substances and allows the prediction of more appropriate materials (pyrolysis temperature and time) in order to remove the given pollutant. Furthermore, the use of CFs as sorptive materials for the extraction of contaminants from water samples to assist with their instrumental detection is outlined. In this sense, the use of CFs and gas chromatography with mass spectrometric detection allows the detection of selected pollutants in the low ng/mL range. Thus, this article provides an integrated approach to the potential of CFs for environmental protection.

Tunable Polarity Carbon Fibers, a Holistic Approach to Environmental Protection

Directory of Open Access Journals (Sweden)

M. Teresa García-Valverde

2018-04-01

Full Text Available The pollution of environmental resources is an issue of social concern worldwide. Chemistry is essential for the design of decontamination strategies and analytical approaches to detect and monitor the contamination. Sorptive materials are usually required in both approaches and green synthesis should be used to minimize their own environmental impact. Carbon fibers (CFs obtained by the pyrolysis of natural cellulose-rich materials fulfill these requirements. In this article, thirty CFs obtained under different conditions are chemically characterized and their sorption ability towards selected pollutants, covering a wide range of polarity, is evaluated. This study provides more profound knowledge related to the polarity of these materials, their interactions with chemical substances and allows the prediction of more appropriate materials (pyrolysis temperature and time in order to remove the given pollutant. Furthermore, the use of CFs as sorptive materials for the extraction of contaminants from water samples to assist with their instrumental detection is outlined. In this sense, the use of CFs and gas chromatography with mass spectrometric detection allows the detection of selected pollutants in the low ng/mL range. Thus, this article provides an integrated approach to the potential of CFs for environmental protection.

Using CO2 Prophet to estimate recovery factors for carbon dioxide enhanced oil recovery

Science.gov (United States)

Attanasi, Emil D.

2017-07-17

IntroductionThe Oil and Gas Journal’s enhanced oil recovery (EOR) survey for 2014 (Koottungal, 2014) showed that gas injection is the most frequently applied method of EOR in the United States and that carbon dioxide (CO2 ) is the most commonly used injection fluid for miscible operations. The CO2-EOR process typically follows primary and secondary (waterflood) phases of oil reservoir development. The common objective of implementing a CO2-EOR program is to produce oil that remains after the economic limit of waterflood recovery is reached. Under conditions of miscibility or multicontact miscibility, the injected CO2 partitions between the gas and liquid CO2 phases, swells the oil, and reduces the viscosity of the residual oil so that the lighter fractions of the oil vaporize and mix with the CO2 gas phase (Teletzke and others, 2005). Miscibility occurs when the reservoir pressure is at least at the minimum miscibility pressure (MMP). The MMP depends, in turn, on oil composition, impurities of the CO2 injection stream, and reservoir temperature. At pressures below the MMP, component partitioning, oil swelling, and viscosity reduction occur, but the efficiency is increasingly reduced as the pressure falls farther below the MMP. CO2-EOR processes are applied at the reservoir level, where a reservoir is defined as an underground formation containing an individual and separate pool of producible hydrocarbons that is confined by impermeable rock or water barriers and is characterized by a single natural pressure system. A field may consist of a single reservoir or multiple reservoirs that are not in communication but which may be associated with or related to a single structural or stratigraphic feature (U.S. Energy Information Administration [EIA], 2000). The purpose of modeling the CO2-EOR process is discussed along with the potential CO2-EOR predictive models. The data demands of models and the scope of the assessments require tradeoffs between reservoir

Comparison of a Mass Balance and an Ecosystem Model Approach when Evaluating the Carbon Cycling in a Lake Ecosystem

International Nuclear Information System (INIS)

Andersson, Eva; Sobek, Sebastian

2006-01-01

Carbon budgets are frequently used in order to understand the pathways of organic matter in ecosystems, and they also have an important function in the risk assessment of harmful substances. We compared two approaches, mass balance calculations and an ecosystem budget, to describe carbon processing in a shallow, oligotrophic hardwater lake. Both approaches come to the same main conclusion, namely that the lake is a net auto trophic ecosystem, in spite of its high dissolved organic carbon and low total phosphorus concentrations. However, there were several differences between the carbon budgets, e.g. in the rate of sedimentation and the air-water flux of CO 2 . The largest uncertainty in the mass balance is the contribution of emergent macrophytes to the carbon cycling of the lake, while the ecosystem budget is very sensitive towards the choice of conversion factors and literature values. While the mass balance calculations produced more robust results, the ecosystem budget gave valuable insights into the pathways of organic matter transfer in the ecosystem. We recommend that when using an ecosystem budget for the risk assessment of harmful substances, mass balance calculations should be performed in parallel in order to increase the robustness of the conclusions

A direct carbon budgeting approach to infer carbon sources and sinks. Design and synthetic application to complement the NACP observation network

Energy Technology Data Exchange (ETDEWEB)

Crevoisier, Cyril; Gloor, Manuel; Gloaguen, Erwan; Sarmiento, Jorge L. [Princeton Univ., NJ (United States). Atmospheric and Oceanic Sciences; Horowitz, Larry W. [Princeton Univ., NJ (United States). Geophysical Fluid Dynamics Laboratory; Sweeney, Colm; Tans, Pieter P. [NOAA/ESRL Global Monitoring Division, Boulder, CO (United States)

2006-11-15

In order to exploit the upcoming regular measurements of vertical carbon dioxide (CO{sub 2}) profiles over North America implemented in the framework of the North American Carbon Program (NACP), we design a direct carbon budgeting approach to infer carbon sources and sinks over the continent using model simulations. Direct budgeting puts a control volume on top of North America, balances air mass in- and outflows into the volume and solves for the surface fluxes. The flows are derived from the observations through a geostatistical interpolation technique called Kriging combined with transport fields from weather analysis. The use of CO{sub 2} vertical profiles simulated by the atmospheric transport model MOZART-2 at the planned 19 stations of the NACP network has given an estimation of the error of 0.39 GtC/yr within the model world. Reducing this error may be achieved through a better estimation of mass fluxes associated with convective processes affecting North America. Complementary stations in the north-west and the north-east are also needed to resolve the variability of CO{sub 2} in these regions. For instance, the addition of a single station near 52 deg N; 110 deg W is shown to decrease the estimation error to 0.34 GtC/yr.

A direct carbon budgeting approach to infer carbon sources and sinks. Design and synthetic application to complement the NACP observation network

International Nuclear Information System (INIS)

Crevoisier, Cyril; Gloor, Manuel; Gloaguen, Erwan; Sarmiento, Jorge L.

2006-01-01

In order to exploit the upcoming regular measurements of vertical carbon dioxide (CO 2 ) profiles over North America implemented in the framework of the North American Carbon Program (NACP), we design a direct carbon budgeting approach to infer carbon sources and sinks over the continent using model simulations. Direct budgeting puts a control volume on top of North America, balances air mass in- and outflows into the volume and solves for the surface fluxes. The flows are derived from the observations through a geostatistical interpolation technique called Kriging combined with transport fields from weather analysis. The use of CO 2 vertical profiles simulated by the atmospheric transport model MOZART-2 at the planned 19 stations of the NACP network has given an estimation of the error of 0.39 GtC/yr within the model world. Reducing this error may be achieved through a better estimation of mass fluxes associated with convective processes affecting North America. Complementary stations in the north-west and the north-east are also needed to resolve the variability of CO 2 in these regions. For instance, the addition of a single station near 52 deg N; 110 deg W is shown to decrease the estimation error to 0.34 GtC/yr

Approaches to greenhouse gas accounting methods for biomass carbon

International Nuclear Information System (INIS)

Downie, Adriana; Lau, David; Cowie, Annette; Munroe, Paul

2014-01-01

This investigation examines different approaches for the GHG flux accounting of activities within a tight boundary of biomass C cycling, with scope limited to exclude all other aspects of the lifecycle. Alternative approaches are examined that a) account for all emissions including biogenic CO 2 cycling – the biogenic method; b) account for the quantity of C that is moved to and maintained in the non-atmospheric pool – the stock method; and c) assume that the net balance of C taken up by biomass is neutral over the short-term and hence there is no requirement to include this C in the calculation – the simplified method. This investigation demonstrates the inaccuracies in both emissions forecasting and abatement calculations that result from the use of the simplified method, which is commonly accepted for use. It has been found that the stock method is the most accurate and appropriate approach for use in calculating GHG inventories, however short-comings of this approach emerge when applied to abatement projects, as it does not account for the increase in biogenic CO 2 emissions that are generated when non-CO 2 GHG emissions in the business-as-usual case are offset. Therefore the biogenic method or a modified version of the stock method should be used to accurately estimate GHG emissions abatement achieved by a project. This investigation uses both the derivation of methodology equations from first principles and worked examples to explore the fundamental differences in the alternative approaches. Examples are developed for three project scenarios including; landfill, combustion and slow-pyrolysis (biochar) of biomass. -- Highlights: • Different approaches can be taken to account for the GHG emissions from biomass. • Simplification of GHG accounting methods is useful, however, can lead to inaccuracies. • Approaches used currently are often inadequate for practises that store carbon. • Accounting methods for emissions forecasting can be inadequate for

An integrated study of the Grayburg/San Andres reservoir, Foster and south Cowden fields, Ector County, Texas. Quarterly report, January 1--March 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Trentham, R.C.; Weinbrandt, R.; Reeves, J.J.

1996-06-17

The principal objective of this research is to demonstrate in the field that 3D seismic data can be used to aid in identifying porosity zones, permeability barriers and thief zones and thereby improve waterflood design. Geologic and engineering data will be integrated with the geophysical data to result in a detailed reservoir characterization. Reservoir simulation will then be used to determine infill drilling potential and the optimum waterflood design for the project area. This design will be implemented and the success of the waterflood evaluated.

Tensile properties of carbon black-filled natural rubber latex films using two different approaches of film preparation

Science.gov (United States)

Jarkasi, Siti Aisyah; Samsuri, Azemi; Hashim, M. Y. Amir; Kamarun, Dzaraini

2017-09-01

A study was structured to investigate the effects of two different approaches of black-filled NRL films preparation on tensile strengths and tensile stress at 100% strain (M100). In the "First Approach", carbon black dispersion was added into the NRL and mixed using mechanical stirrer. Then the black-filled NRL was coagulated with acetic acid and dried to form NR black-filled masterbatch. This black-filled NR masterbatch was then masticated and mixed with other compounding ingredients on the 2-roll mill. In the "Second Approach", carbon black dispersion was mixed with NRL plus all other compounding ingredients using a mechanical stirrer at high mechanical stirring speed (200 rpm) for 3 hrs. Tensile test-pieces from these two rubber specimens were tested according to ISO37. It was observed that the tensile strengths are affected by both methods. In the case of masticated latex masterbatch, the black-filled NRL films gave higher tensile strength (25-27 MPa) as compared to un-masticated black-filled NRL films (11-17 MPa). The optimum amount of filler loading for highest tensile strength in both approaches was 20 phr of carbon black. However these different approaches did not give significant effect to the elongation at break, EB and M100. SEM images of samples prepared from both approaches suggested that the dispersion of filler in the rubber matrix was better in the masticated samples compared to the un-masticated samples. The reason for the difference in the tensile strength between the two black-filled rubbers might be associated with the degree of dispersions and the uniformity of the dispersions within the rubber matrix. The first mixing approach involved high mechanical shearing action during mastication and mixing process on the 2-roll mill. The high shearing actions were able to breakdown filler aggregates efficiently and distributed the dispersed filler uniformly within the rubber matrix. In the second approach, the breakdown of filler aggregates relied on

Carbon foam/hydroxyapatite coating for carbon/carbon composites: Microstructure and biocompatibility

Energy Technology Data Exchange (ETDEWEB)

Zhang, Leilei, E-mail: zhangleilei1121@aliyun.com; Li, Hejun; Li, Kezhi; Zhang, Shouyang; Lu, Jinhua; Li, Wei; Cao, Sheng; Wang, Bin

2013-12-01

To improve the surface biocompatibility of carbon/carbon composites, a carbon foam/hydroxyapatite coating was applied using a combination method of slurry procedure and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The biocompatibility of the carbon foam/hydroxyapatite coating was investigated by osteoblast-like MG63 cell culture tests. The results showed that the carbon foam could provide a large number of pores on the surface of carbon/carbon composites. The hydroxyapatite crystals could infiltrate into the pores and form the carbon foam/hydroxyapatite coating. The coating covered the carbon/carbon composites fully and uniformly with slice morphology. The cell response tests showed that the MG63 cells on carbon foam/hydroxyapatite coating had a better cell adhesion and cell proliferation than those on uncoated carbon/carbon composites. The carbon foam/hydroxyapatite coatings were cytocompatible and were beneficial to improve the biocompatibility. The approach presented here may be exploited for fabrication of carbon/carbon composite implant surfaces.

Carbon foam/hydroxyapatite coating for carbon/carbon composites: Microstructure and biocompatibility

International Nuclear Information System (INIS)

Zhang, Leilei; Li, Hejun; Li, Kezhi; Zhang, Shouyang; Lu, Jinhua; Li, Wei; Cao, Sheng; Wang, Bin

2013-01-01

To improve the surface biocompatibility of carbon/carbon composites, a carbon foam/hydroxyapatite coating was applied using a combination method of slurry procedure and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The biocompatibility of the carbon foam/hydroxyapatite coating was investigated by osteoblast-like MG63 cell culture tests. The results showed that the carbon foam could provide a large number of pores on the surface of carbon/carbon composites. The hydroxyapatite crystals could infiltrate into the pores and form the carbon foam/hydroxyapatite coating. The coating covered the carbon/carbon composites fully and uniformly with slice morphology. The cell response tests showed that the MG63 cells on carbon foam/hydroxyapatite coating had a better cell adhesion and cell proliferation than those on uncoated carbon/carbon composites. The carbon foam/hydroxyapatite coatings were cytocompatible and were beneficial to improve the biocompatibility. The approach presented here may be exploited for fabrication of carbon/carbon composite implant surfaces.

A diagonal approach for the catalytic transformation of carbon dioxide

International Nuclear Information System (INIS)

Gomes, Christophe

2013-01-01

Emissions of carbon dioxide are growing with the massive utilization of hydrocarbons for the production of energy and chemicals, resulting in a threatening global warming. The development of a more sustainable economy is urging to reduce the fingerprint of our current way of life. In this perspective, the organic chemistry industry will face important challenges in the next decades to replace hydrocarbons as a feedstock and use carbon-free energy sources. To tackle this challenge, new catalytic processes have been designed to convert CO 2 to high energy and value-added chemicals (formamides, N-heterocycles and methanol), using a novel diagonal approach. The energy efficiency of the new transformations is ensured by the utilization of mild reductants such as hydro-silanes and hydro-boranes. Importantly the reactions are promoted by organic catalysts, which circumvent the problems of cost, abundance and toxicity usually encountered with metal complexes. Based on theoretical and experimental studies, the understanding of the mechanisms involved in these reactions allowed the rational optimization of the catalysts as well as the reaction conditions, in order to match the requirements of sustainable chemistry. (author) [fr

Elastic-plastic fracture analysis of carbon steel piping using the latest CEGB R6 approach

International Nuclear Information System (INIS)

Kanno, S.; Hasegawa, K.; Shimizu, T.; Kobayashi, H.

1991-01-01

The elastic-plastic fracture of carbon steel piping having various pipe diameters and circumferential crack angles and subjected to a bending moment is analyzed using the latest United Kingdom Central Electricity Generating Board R6 approach. The elastic-plastic fracture criterion must be applied instead of the plastic collapse criterion with increase of the pipe diameter and the crack angle. A simplified elastic-plastic fracture analysis procedure based on the R6 approach is proposed. (author)

New approach to synthesis of carbon nanotubes

International Nuclear Information System (INIS)

Ha, Jong Keun; Choi, Kyo Hong; Cho, Kwon Koo; Kim, Ki Won; Nam, Tae Hyun; Ahn, Hyo Jun; Ahn, Jou Hyun; Cho, Gyu Bong

2007-01-01

Carbon nanotubes (CNTs) have been synthesized through chemical vapor deposition in argon gas atmosphere using Fe-2.5%Mo alloyed nanoparticles as a catalyst and H 2 /CH 4 gas mixture as a reaction gas. Fe-2.5 wt.%Mo alloyed nanoparticles with average diameter of 7, 20, 45 and 85 nm are prepared by the chemical vapor condensation process using the pyrolysis of iron pentacarbonyl (Fe(CO) 5 ) and molybdenum hexacarbonyl (Mo(CO) 6 ). The morphologies of the CNTs are controlled by adjusting the nanoparticle size, reaction gas ratio and reaction temperature. With decreasing nanoparticle size under the same experimental conditions, the degree of crystalline perfection increases gradually and the morphologies of the carbon nanotubes vary from multi wall carbon nanotubes to single wall carbon nanotubes. Also, the ratio of reaction gas has an effect on the morphology and the degree of crystallinity of CNTs. In this work, it is suggested that morphology, diameter and degree of crystallinity of CNTs could be controlled by adjusting the reaction gas ratio, reaction temperature and catalyst size

Generic model for calculating carbon footprint of milk using four different LCA modelling approaches

DEFF Research Database (Denmark)

Dalgaard, Randi; Schmidt, Jannick Højrup; Flysjö, Anna

2014-01-01

The aim of the study is to develop a tool, which can be used for calculation of carbon footprint (using a life cycle assessment (LCA) approach) of milk both at a farm level and at a national level. The functional unit is ‘1 kg energy corrected milk (ECM) at farm gate’ and the applied methodology...

Three approaches for estimating recovery factors in carbon dioxide enhanced oil recovery

Science.gov (United States)

Verma, Mahendra K.

2017-07-17

PrefaceThe Energy Independence and Security Act of 2007 authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2) and requested the USGS to estimate the “potential volumes of oil and gas recoverable by injection and sequestration of industrial carbon dioxide in potential sequestration formations” (42 U.S.C. 17271(b)(4)). Geologic CO2 sequestration associated with enhanced oil recovery (EOR) using CO2 in existing hydrocarbon reservoirs has the potential to increase the U.S. hydrocarbon recoverable resource. The objective of this report is to provide detailed information on three approaches that can be used to calculate the incremental recovery factors for CO2-EOR. Therefore, the contents of this report could form an integral part of an assessment methodology that can be used to assess the sedimentary basins of the United States for the hydrocarbon recovery potential using CO2-EOR methods in conventional oil reservoirs.

An assessment of high carbon stock and high conservation value approaches to sustainable oil palm cultivation in Gabon

Science.gov (United States)

Austin, Kemen G.; Lee, Michelle E.; Clark, Connie; Forester, Brenna R.; Urban, Dean L.; White, Lee; Kasibhatla, Prasad S.; Poulsen, John R.

2017-01-01

Industrial-scale oil palm cultivation is rapidly expanding in Gabon, where it has the potential to drive economic growth, but also threatens forest, biodiversity and carbon resources. The Gabonese government is promoting an ambitious agricultural expansion strategy, while simultaneously committing to minimize negative environmental impacts of oil palm agriculture. This study estimates the extent and location of suitable land for oil palm cultivation in Gabon, based on an analysis of recent trends in plantation permitting. We use the resulting suitability map to evaluate two proposed approaches to minimizing negative environmental impacts: a High Carbon Stock (HCS) approach, which emphasizes forest protection and climate change mitigation, and a High Conservation Value (HCV) approach, which focuses on safeguarding biodiversity and ecosystems. We quantify the forest area, carbon stock, and biodiversity resources protected under each approach, using newly developed maps of priority species distributions and forest biomass for Gabon. We find 2.7-3.9 Mha of suitable or moderately suitable land that avoid HCS areas, 4.4 million hectares (Mha) that avoid HCV areas, and 1.2-1.7 Mha that avoid both. This suggests that Gabon’s oil palm production target could likely be met without compromising important ecosystem services, if appropriate safeguards are put in place. Our analysis improves understanding of suitability for oil palm in Gabon, determines how conservation strategies align with national targets for oil palm production, and informs national land use planning.

Convergence of carbon dioxide emissions in Chinese cities: A continuous dynamic distribution approach

International Nuclear Information System (INIS)

Wu, Jianxin; Wu, Yanrui; Guo, Xiumei; Cheong, Tsun Se

2016-01-01

This paper investigates the spatial dynamics of per capita carbon dioxide (CO_2) emissions in China. The analyses are conducted by employing a continuous dynamic distribution approach and panel data of 286 cities at the prefecture and above-prefecture level. The results show that per capita CO_2 emissions tend to converge during the sample period of 2002–2011. However, multimodality is found in the ergodic distribution of the full sample. It is also found that there is more persistence in cities with low per capita CO_2 emissions, and more mobility in cities with high per capita CO_2 emissions. The analyses also show that the dynamics of per capita CO_2 emissions are significantly different among various geographical, income and environmental policy groups. The conditional distribution analyses indicate that multimodality cannot be explained independently by any one of the two factors, namely geographical location or income level. The findings in this study may have important policy implications for CO_2 abatement in China. - Highlights: •Spatial dynamics of per capita carbon dioxide (CO_2) emissions in 286 Chinese cities. •A continuous dynamic distribution approach and panel data. •Multimodality is found in the ergodic distribution of the full sample. •Significantly different dynamics among various city groups.

Carbon Impact Analytics - Designing low carbon indices based on Carbon Impact Analytics indicators

International Nuclear Information System (INIS)

2016-01-01

Investors are increasingly exposed to carbon risks and now face the challenge of managing these risks and developing climate-resilient investment strategies. Carbon Impact Analytics (CIA), an innovative methodology for analyzing the full carbon impact of a portfolio or index, equips investors and asset managers with the tools necessary to reduce their climate-related risks but also to seize the opportunities offered by the ongoing energy transition. Investors, asset managers and other financial institutions may use CIA results to: - measure and manage risks, - optimize their contribution to the energy transition, - seize opportunities associated with climate change mitigation, - report on GHG emissions and savings (for regulatory purposes or voluntarily), - engage in dialogue with companies, - reallocate investment portfolios, - and build new low-carbon indices. In this report, Carbone 4 offers a detailed look into how CIA indicators can be used to either 1) reallocate an existing portfolio or index to achieve maximal carbon performance or 2) build new low carbon indices from the ground up, drawn from Carbone 4's ever-growing database of CIA-analyzed firms. Two main levers were used to optimize CIA output: 1. Sectorial reallocation: exclusion of fossil fuel-related sectors or insertion of low carbon pure players; 2. Intra-sectorial reallocation: best-in-class approach within a sector. Sectorial and intra-sectorial methods may be applied in conjunction with one another to maximize results. For example, a best-in-class + fossil fuel-free index may be constructed by first excluding the fossil fuel sector and then applying a CIA best-in-class approach to all remaining sectors. This report offers a detailed look into how CIA indicators can be used to rework portfolios or indices to maximize carbon performance or to build low carbon indices from the ground up. These methods are illustrated via two preliminary examples of indices designed by Carbone 4: the reallocated

A new approach combining analytical methods for workplace exposure assessment of inhalable multi-walled carbon nanotubes

NARCIS (Netherlands)

Tromp, P.C.; Kuijpers, E.; Bekker, C.; Godderis, L.; Lan, Q.; Jedynska, A.D.; Vermeulen, R.; Pronk, A.

2017-01-01

To date there is no consensus about the most appropriate analytical method for measuring carbon nanotubes (CNTs), hampering the assessment and limiting the comparison of data. The goal of this study is to develop an approach for the assessment of the level and nature of inhalable multi-wall CNTs

Numerical modelling of carbonate platforms and reefs: approaches and opportunities

Energy Technology Data Exchange (ETDEWEB)

Dalmasso, H.; Montaggioni, L.F.; Floquet, M. [Universite de Provence, Marseille (France). Centre de Sedimentologie-Palaeontologie; Bosence, D. [Royal Holloway University of London, Egham (United Kingdom). Dept. of Geology

2001-07-01

This paper compares different computing procedures that have been utilized in simulating shallow-water carbonate platform development. Based on our geological knowledge we can usually give a rather accurate qualitative description of the mechanisms controlling geological phenomena. Further description requires the use of computer stratigraphic simulation models that allow quantitative evaluation and understanding of the complex interactions of sedimentary depositional carbonate systems. The roles of modelling include: (1) encouraging accuracy and precision in data collection and process interpretation (Watney et al., 1999); (2) providing a means to quantitatively test interpretations concerning the control of various mechanisms on producing sedimentary packages; (3) predicting or extrapolating results into areas of limited control; (4) gaining new insights regarding the interaction of parameters; (5) helping focus on future studies to resolve specific problems. This paper addresses two main questions, namely: (1) What are the advantages and disadvantages of various types of models? (2) How well do models perform? In this paper we compare and discuss the application of five numerical models: CARBONATE (Bosence and Waltham, 1990), FUZZIM (Nordlund, 1999), CARBPLAT (Bosscher, 1992), DYNACARB (Li et al., 1993), PHIL (Bowman, 1997) and SEDPAK (Kendall et al., 1991). The comparison, testing and evaluation of these models allow one to gain a better knowledge and understanding of controlling parameters of carbonate platform development, which are necessary for modelling. Evaluating numerical models, critically comparing results from models using different approaches, and pushing experimental tests to their limits, provide an effective vehicle to improve and develop new numerical models. A main feature of this paper is to closely compare the performance between two numerical models: a forward model (CARBONATE) and a fuzzy logic model (FUZZIM). These two models use common

Theoretical study of the structure, energetics, and dynamics of silicon and carbon systems using tight-binding approaches

International Nuclear Information System (INIS)

Xu, Chunhui.

1991-01-01

Semiempirical interatomic potentials are developed for silicon and carbon by modeling the total energy of the system using tight-binding approaches. The parameters of the models were obtained by fitting to results from accurate first-principles Local Density Functional calculations. Applications to the computation of phonons as a function of volume for diamond-structured silicon and carbon and the thermal expansions for silicon and diamond yields results which agree well with experiment. The physical origin of the negative thermal expansion observed in silicon is explained. A tight-binding total energy model is generated capable of describing carbon systems with a variety of atomic coordinations and topologies. The model reproduces the total energy versus volume curves of various carbon polytypes as well as phonons and elastic constants of diamond and graphite. The model has also been used in the molecular-dynamics simulation of the properties of carbon clusters. The calculated ground-state geometries of small clusters (C 2 --C 10 ) correlates well with results from accurate quantum chemical calculations, and the structural trend of clusters from C 2 to C 60 are investigated. 67 refs., 19 figs

Combined spectroscopy approaches towards the study of truly 1D carbon-based structures

Energy Technology Data Exchange (ETDEWEB)

Ayala, Paola, E-mail: paola.ayala@univie.ac.at [University of Vienna (Austria)

2016-07-01

Full text: The applicability of nanostructured materials owes great part of its success to the proper understanding of their physical properties and the interaction with the surrounding environment. Applications related to improving solar cell efficiency are among the fields in which understanding the behavior of nanomaterials is critical. In this talk I will present an overview and progress report of the use of different spectroscopy techniques such as Raman, photoemission and X-ray absorption spectroscopy as key tools to understand the properties of low dimensional carbon systems with sp{sup 2} hybridization, as well as one dimensional carbyne chains. Keeping in mind that the properties of sp{sup 2} hybridized materials can be nicely tuned via different functionalization methods like substitutional doping, lattice modifications, adsorption of species, among others, this overview will provide an approach to how these techniques can be utilized to understand and analyze changes in the site-selective valence and conduction bands of single walled carbon nanotubes and graphene. (author)

Live tree carbon stock equivalence of fire and fuels extension to the Forest Vegetation Simulator and Forest Inventory and Analysis approaches

Science.gov (United States)

James E. Smith; Coeli M. Hoover

2017-01-01

The carbon reports in the Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) provide two alternate approaches to carbon estimates for live trees (Rebain 2010). These are (1) the FFE biomass algorithms, which are volumebased biomass equations, and (2) the Jenkins allometric equations (Jenkins and others 2003), which are diameter based. Here, we...

An Exogenous Surfactant-Producing Bacillus subtilis Facilitates Indigenous Microbial Enhanced Oil Recovery.

Science.gov (United States)

Gao, Peike; Li, Guoqiang; Li, Yanshu; Li, Yan; Tian, Huimei; Wang, Yansen; Zhou, Jiefang; Ma, Ting

2016-01-01

This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR) process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous B. subtilis and indigenous microbial populations. The exogenous B. subtilis is a lipopeptide producer, with a short growth cycle and no oil-degrading ability. The B. subtilis facilitates the IMEOR process through improving oil emulsification and accelerating microbial growth with oil as the carbon source. Microbial community studies using quantitative PCR and high-throughput sequencing revealed that the exogenous B. subtilis could live together with reservoir microbial populations, and did not exert an observable inhibitory effect on the indigenous microbial populations during nutrient stimulation. Core-flooding tests showed that the combined exogenous and indigenous microbial flooding increased oil displacement efficiency by 16.71%, compared with 7.59% in the control where only nutrients were added, demonstrating the application potential in enhanced oil recovery in water-flooded reservoirs, in particular, for reservoirs where IMEOR treatment cannot effectively improve oil recovery.

The Role of Carbon Accountant in Corporate Carbon Management Systems: A Holistic Approach

Directory of Open Access Journals (Sweden)

Francis Chinedu Egbunike

2017-12-01

Full Text Available Carbon accounting consists of a combination of advanced cost allocation techniques such as activity-based management and life-cycle costing; that improve the identification and assignments of carbon-related expenses and overheads to such objects as products, services, customers and organizational processes. The study therefore sets out to find the role of carbon accountant in corporate management systems. Data used for this investigation were collected from primary and secondary sources. Primary data are first-hand information from respondents while Secondary data include textbook, Annual Reports and financial statements and internet facilities. The study employed descriptive survey and ex-post facto research design and the formulated hypotheses were tested by use of T-Test and OLS Regression. Based on the analysis and the hypothesis tested, it showed that there is a statistically significant relationship between carbon accounting and corporate performance of selected quoted Manufacturing Companies and based on this findings, it was recommended amongst others that, adaptation to conditions that include long-term changing dynamics of the natural environment should be encouraged and the focus of finance and accounting system should not only cover short-term outcomes and management of short-term costing, reporting and disclosure but also long-term climate risks.

Upscaling Our Approach to Peatland Carbon Sequestration: Remote Sensing as a Tool for Carbon Flux Estimation.

Science.gov (United States)

Lees, K.; Khomik, M.; Clark, J. M.; Quaife, T. L.; Artz, R.

2017-12-01

Peatlands are an important part of the Earth's carbon cycle, comprising approximately a third of the global terrestrial carbon store. However, peatlands are sensitive to climatic change and human mismanagement, and many are now degraded and acting as carbon sources. Restoration work is being undertaken at many sites around the world, but monitoring the success of these schemes can be difficult and costly using traditional methods. A landscape-scale alternative is to use satellite data in order to assess the condition of peatlands and estimate carbon fluxes. This work focuses on study sites in Northern Scotland, where parts of the largest blanket bog in Europe are being restored from forest plantations. A combination of laboratory and fieldwork has been used to assess the Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP) and respiration of peatland sites in different conditions, and the climatic vulnerability of key peat-forming Sphagnum species. The results from these studies have been compared with spectral data in order to evaluate the extent to which remote sensing can function as a source of information for peatland health and carbon flux models. This work considers particularly the effects of scale in calculating peatland carbon flux. Flux data includes chamber and eddy covariance measurements of carbon dioxide, and radiometric observations include both handheld spectroradiometer results and satellite images. Results suggest that despite the small-scale heterogeneity and unique ecosystem factors in blanket bogs, remote sensing can be a useful tool in monitoring peatland health and carbon sequestration. In particular, this study gives unique insights into the relationships between peatland vegetation, carbon flux and spectral reflectance.

The role of carbon sequestration and the tonne-year approach in fulfilling the objective of climate convention

International Nuclear Information System (INIS)

Korhonen, Riitta; Pingoud, Kim; Savolainen, Ilkka; Matthews, Robert

2002-01-01

Carbon can be sequestered from the atmosphere to forests in order to lower the atmospheric carbon dioxide concentration. Tonne-years of sequestered carbon have been suggested to be used as a measure of global warming impact for these projects of finite lifetimes. It is illustrated here by simplified example cases that the objective of the stabilisation of the atmospheric greenhouse gas concentrations expressed in the UN Climate convention and the tonne-year approach can be in contradiction. Tonne-years generated by the project can indicate that carbon sequestration helps in the mitigation of climate change even when the impact of the project on the CO 2 concentration is that concentration increases. Hence, the use of the tonne-years might waste resources of fulfilling the objective of the convention. The studied example cases are closely related to the IPCC estimates on global forestation potentials by 2050. It is also illustrated that the use of bioenergy from the reforested areas to replace fossil fuels can in the long term contribute more effectively to the control of carbon dioxide concentrations than permanent sequestration of carbon to forests. However, the estimated benefits depend on the time frame considered, whether we are interested in the decadal scale of controlling of the rate of climate change or in the centennial scale of controlling or halting the climate change

Carbon black nanoparticles film electrode prepared by using substrate-induced deposition approach

Energy Technology Data Exchange (ETDEWEB)

Svegl, Irena Grabec; Bele, Marjan [National Institute of Chemistry, P.O. Box 660, SI-1001 Ljubljana (Slovenia); Ogorevc, Bozidar [National Institute of Chemistry, P.O. Box 660, SI-1001 Ljubljana (Slovenia)], E-mail: bogorevc@ki.si

2008-11-03

A new type of carbon film electrode, composed of a thin layer of tightly packed carbon black (CB) nanoparticles deposited onto a gelatin-covered indium tin oxide/glass support using the surface-induced deposition (SID) approach, is presented. Some parameters of the novel SID method were optimized and the surface image and functionalization of the investigated carbon black film electrode (CBFE) was inspected by employing scanning electron microscopy and infrared spectroscopy. A cyclic voltammetry (CV) study was conducted in which the electron-transfer kinetics and CBFE interfacial characteristics were evaluated employing several selected reference redox systems, such as [Ru(NH{sub 3}){sub 6}]{sup 3+/2+}, [Fe(CN){sub 6}]{sup 3-/4-} and Fe{sup 3+/2+} in aqueous, and ferrocene/ferrocenium in acetonitrile media. CV recordings were also performed in order to compare the electrochemical behavior of the CBFE with that of some well-known and established bare carbon-based electrodes. In order to confirm the validity of the CB film preparation method, the electroanalytical performance of the proposed CBFE was examined by carrying out linear sweep voltammetry of ascorbic acid (AA), anodic stripping square-wave voltammetry of Cu(II) in acidic medium, and amperometric measurements of hydrogen peroxide under flow injection conditions. The sensing characteristics of the novel carbon film electrode, demonstrated in this preliminary study, comprise: (i) a wide working potential window ranging from +1.0 to -1.3 V (depending on the solution pH), (ii) a wide applicable pH range (at least from 2 to 12), (iii) low voltammetric background (<5 {mu}A cm{sup -2}), (iv) a satisfactory linear voltammetric and amperometric response (r{sup 2} > 0.99) to various analytes, (v) good reproducibility (for example, r.s.d. of 2% in amperometric detection of H{sub 2}O{sub 2} and r.s.d. of 8.5% for electrode-to-electrode CV runs), and (vi) stable and fast current response (at least 100 CV runs with

Oil Recovery Increases by Low-Salinity Flooding: Minnelusa and Green River Formations

Energy Technology Data Exchange (ETDEWEB)

Eric P. Robertson

2010-09-01

Waterflooding is by far the most widely used method in the world to increase oil recovery. Historically, little consideration has been given in reservoir engineering practice to the effect of injection brine composition on waterflood displacement efficiency or to the possibility of increased oil recovery through manipulation of the composition of the injected water. However, recent work has shown that oil recovery can be significantly increased by modifying the injection brine chemistry or by injecting diluted or low salinity brine. This paper reports on laboratory work done to increase the understanding of improved oil recovery by waterflooding with low salinity injection water. Porous media used in the studies included outcrop Berea sandstone (Ohio, U.S.A.) and reservoir cores from the Green River formation of the Uinta basin (Utah, U.S.A.). Crude oils used in the experimental protocols were taken from the Minnelusa formation of the Powder River basin (Wyoming, U.S.A.) and from the Green River formation, Monument Butte field in the Uinta basin. Laboratory corefloods using Berea sandstone, Minnelusa crude oil, and simulated Minnelusa formation water found a significant relationship between the temperature at which the oil- and water-saturated cores were aged and the oil recovery resulting from low salinity waterflooding. Lower aging temperatures resulted in very little to no additional oil recovery, while cores aged at higher temperatures resulted in significantly higher recoveries from dilute-water floods. Waterflood studies using reservoir cores and fluids from the Green River formation of the Monument Butte field also showed significantly higher oil recoveries from low salinity waterfloods with cores flooded with fresher water recovering 12.4% more oil on average than those flooded with undiluted formation brine.

Carbon exchange in Western Siberian watershed mires and implication for the greenhouse effect. A spatial temporal modeling approach

Energy Technology Data Exchange (ETDEWEB)

Borren, W.

2007-01-19

The vast watershed mires of Western Siberia formed a significant sink of carbon during the Holocene. Because of their large area these mires might play an important role in the carbon exchange between terrestrial ecosystems and the atmosphere. However, estimation of the Holocene and future carbon balance of whole Western Siberian mires is hampered by the lack of spatially resolved models. The main objective was to assess the carbon exchange fluxes of the mires using a 3-D dynamic approach. These exchange fluxes comprise the sequestration of carbon dioxide (CO2) by peat growth, the emission of methane (CH4) by anaerobic peat decay and the emission of CO2 by aerobic peat decay. From the detailed analysis of peat cores from different sites in the southern taiga of Western Siberia, it emerged that Holocene peat growth and carbon accumulation had different trends, caused by variations in vegetation succession. These differences were strongly influenced by the position in the landscape. Therefore, the effect of climatic change on mire development varied spatially. The indirect effects of climate change through local hydrology appeared to be more important than direct influences of changes in precipitation and temperature. Mire development is closely connected to hydrological dynamics. In the thesis a 3-D dynamic modeling approach is described that makes use of groundwater modeling. In successive timesteps peat growth and decay as well as mire type distribution were calculated, depending on hydrological conditions. The model was forced with a paleo-precipitation record to include variable climatic input. The model results show the Holocene development of a watershed mire from a few small spots to a contiguous mire landscape. As hydrology is the major limiting factor, the mire development is most sensitive to precipitation and evapotranspiration. Under unchanged conditions the mire will grow further, eventually reaching its maximum peat thickness around 11400 yr A.D. Under

Carbon exchange in Western Siberian watershed mires and implication for the greenhouse effect. A spatial temporal modeling approach

International Nuclear Information System (INIS)

Borren, W.

2007-01-01

The vast watershed mires of Western Siberia formed a significant sink of carbon during the Holocene. Because of their large area these mires might play an important role in the carbon exchange between terrestrial ecosystems and the atmosphere. However, estimation of the Holocene and future carbon balance of whole Western Siberian mires is hampered by the lack of spatially resolved models. The main objective was to assess the carbon exchange fluxes of the mires using a 3-D dynamic approach. These exchange fluxes comprise the sequestration of carbon dioxide (CO2) by peat growth, the emission of methane (CH4) by anaerobic peat decay and the emission of CO2 by aerobic peat decay. From the detailed analysis of peat cores from different sites in the southern taiga of Western Siberia, it emerged that Holocene peat growth and carbon accumulation had different trends, caused by variations in vegetation succession. These differences were strongly influenced by the position in the landscape. Therefore, the effect of climatic change on mire development varied spatially. The indirect effects of climate change through local hydrology appeared to be more important than direct influences of changes in precipitation and temperature. Mire development is closely connected to hydrological dynamics. In the thesis a 3-D dynamic modeling approach is described that makes use of groundwater modeling. In successive timesteps peat growth and decay as well as mire type distribution were calculated, depending on hydrological conditions. The model was forced with a paleo-precipitation record to include variable climatic input. The model results show the Holocene development of a watershed mire from a few small spots to a contiguous mire landscape. As hydrology is the major limiting factor, the mire development is most sensitive to precipitation and evapotranspiration. Under unchanged conditions the mire will grow further, eventually reaching its maximum peat thickness around 11400 yr A.D. Under

A simple approach to estimate daily loads of total, refractory, and labile organic carbon from their seasonal loads in a watershed.

Science.gov (United States)

Ouyang, Ying; Grace, Johnny M; Zipperer, Wayne C; Hatten, Jeff; Dewey, Janet

2018-05-22

Loads of naturally occurring total organic carbons (TOC), refractory organic carbon (ROC), and labile organic carbon (LOC) in streams control the availability of nutrients and the solubility and toxicity of contaminants and affect biological activities through absorption of light and complex metals with production of carcinogenic compounds. Although computer models have become increasingly popular in understanding and management of TOC, ROC, and LOC loads in streams, the usefulness of these models hinges on the availability of daily data for model calibration and validation. Unfortunately, these daily data are usually insufficient and/or unavailable for most watersheds due to a variety of reasons, such as budget and time constraints. A simple approach was developed here to calculate daily loads of TOC, ROC, and LOC in streams based on their seasonal loads. We concluded that the predictions from our approach adequately match field measurements based on statistical comparisons between model calculations and field measurements. Our approach demonstrates that an increase in stream discharge results in increased stream TOC, ROC, and LOC concentrations and loads, although high peak discharge did not necessarily result in high peaks of TOC, ROC, and LOC concentrations and loads. The approach developed herein is a useful tool to convert seasonal loads of TOC, ROC, and LOC into daily loads in the absence of measured daily load data.

Carbon Sequestration in a Large Hydroelectric Reservoir: An Integrative Seismic Approach

NARCIS (Netherlands)

Mendonca, R.; Kosten, S.; Sobek, S.; Cole, J.J.; Bastos, A.C.; Albuquerque, A.L.; Cardoso, S.J.; Roland, F.

2014-01-01

Artificial reservoirs likely accumulate more carbon than natural lakes due to their unusually high sedimentation rates. Nevertheless, the actual magnitude of carbon accumulating in reservoirs is poorly known due to a lack of whole-system studies of carbon burial. We determined the organic carbon

An index-based approach to assessing recalcitrance and soil carbon sequestration potential of engineered black carbons (biochars).

Science.gov (United States)

Harvey, Omar R; Kuo, Li-Jung; Zimmerman, Andrew R; Louchouarn, Patrick; Amonette, James E; Herbert, Bruce E

2012-02-07

The ability of engineered black carbons (or biochars) to resist abiotic and, or biotic degradation (herein referred to as recalcitrance) is crucial to their successful deployment as a soil carbon sequestration strategy. A new recalcitrance index, the R(50), for assessing biochar quality for carbon sequestration is proposed. The R(50) is based on the relative thermal stability of a given biochar to that of graphite and was developed and evaluated with a variety of biochars (n = 59), and soot-like black carbons. Comparison of R(50), with biochar physicochemical properties and biochar-C mineralization revealed the existence of a quantifiable relationship between R(50) and biochar recalcitrance. As presented here, the R(50) is immediately applicable to pre-land application screening of biochars into Class A (R(50) ≥ 0.70), Class B (0.50 ≤ R(50) carbon sequestration classes. Class A and Class C biochars would have carbon sequestration potential comparable to soot/graphite and uncharred plant biomass, respectively, whereas Class B biochars would have intermediate carbon sequestration potential. We believe that the coupling of the R(50), to an index-based degradation, and an economic model could provide a suitable framework in which to comprehensively assess soil carbon sequestration in biochars.

The effect of carbon tax on carbon emission abatement and GDP: a case study

Science.gov (United States)

Liu, Xiao; Leung, Yee; Xu, Yuan; Yung, Linda Chor Wing

2017-10-01

Carbon tax has been advocated as an effective economic instrument for the abatement of CO2 emission by various countries, including China, the world's biggest carbon emission country. However, carbon emission abatement cannot be done while ignoring the impact on economic growth. A delicate balance needs to be achieved between the two to find an appropriate pathway for sustainable development. This paper applies a multi-objective optimization approach to analyze the impact of levying carbon tax on the energy-intensive sectors of Guangdong province in China under the constraint of emission reduction target. This approach allows us to evaluate carbon emission minimization while maximizing GDP. For policy analysis, we construct five scenarios for evaluation and optimal choice. The results of the analysis show that a lower initial carbon tax rate is not necessarily better, and that a carbon tax is an effective means to reduce CO2 emissions while maintaining a certain level of GDP growth.

75 FR 52362 - Notice of Intent To Prepare an Environmental Impact Statement and To Conduct Public Scoping for...

Science.gov (United States)

2010-08-25

... through the local news media and the BLM Web site http://www.blm.gov/ut/st/en/fo/vernal/planning.html at... consists of secondary recovery using waterflood methods and deep gas drilling. Waterflood methods involve... deep gas wells, 238 miles of new access road, 361 miles of upgraded road, 599 miles of rights-of-way...

Investigation of geometrical effects in the carbon allotropes manipulation based on AFM: multiscale approach

Energy Technology Data Exchange (ETDEWEB)

Korayem, M. H., E-mail: hkorayem@iust.ac.ir; Hefzabad, R. N.; Homayooni, A.; Aslani, H. [Iran University of Science and Technology, Robotic Research Laboratory, Center of Excellence in Experimental Solid Mechanics and Dynamics, School of Mechanical Engineering (Iran, Islamic Republic of)

2017-01-15

Carbon allotropes are used as nanocarriers for drug and cell delivery. To obtain an accurate result in the nanoscale, it is important to use a precise model. In this paper, a multiscale approach is presented to investigate the manipulation process of carbon allotropes based on atomic force microscopy (AFM). For this purpose, the AFM setup is separated into two parts with different sizes as macro field (MF) and nano field (NF). Using Kirchhoff’s plate model, the cantilever (the main part of MF) is modeled. The molecular dynamics method is applied to model the NF part, and then the MF and NF are coupled with the multiscale algorithm. With this model, by considering the effect of size and shape, the manipulation of carbon allotropes is carried out. The manipulations of armchair CNTs and fullerenes are performed to study the diameter changing effects. The result shows that the manipulation and friction force increases by increasing the diameter. The result of the indentation depth for the armchair CNTs indicates that decreasing the diameter causes the indentation depth to reduce. Moreover, the manipulations of four kinds of carbon allotropes with the same number of atoms have been studied to investigate the geometrical effects. The shapes of these nanoparticles change from sphere to cylinder. The results illustrate that the manipulation and the friction force decrease as the nanoparticle shape varies from sphere to cylinder. The Von-Mises results demonstrate that by changing the nanoparticle shape from the spherical to the cylindrical form, the stress increases, although the manipulation force reduces.

Investigation of geometrical effects in the carbon allotropes manipulation based on AFM: multiscale approach

International Nuclear Information System (INIS)

Korayem, M. H.; Hefzabad, R. N.; Homayooni, A.; Aslani, H.

2017-01-01

Carbon allotropes are used as nanocarriers for drug and cell delivery. To obtain an accurate result in the nanoscale, it is important to use a precise model. In this paper, a multiscale approach is presented to investigate the manipulation process of carbon allotropes based on atomic force microscopy (AFM). For this purpose, the AFM setup is separated into two parts with different sizes as macro field (MF) and nano field (NF). Using Kirchhoff’s plate model, the cantilever (the main part of MF) is modeled. The molecular dynamics method is applied to model the NF part, and then the MF and NF are coupled with the multiscale algorithm. With this model, by considering the effect of size and shape, the manipulation of carbon allotropes is carried out. The manipulations of armchair CNTs and fullerenes are performed to study the diameter changing effects. The result shows that the manipulation and friction force increases by increasing the diameter. The result of the indentation depth for the armchair CNTs indicates that decreasing the diameter causes the indentation depth to reduce. Moreover, the manipulations of four kinds of carbon allotropes with the same number of atoms have been studied to investigate the geometrical effects. The shapes of these nanoparticles change from sphere to cylinder. The results illustrate that the manipulation and the friction force decrease as the nanoparticle shape varies from sphere to cylinder. The Von-Mises results demonstrate that by changing the nanoparticle shape from the spherical to the cylindrical form, the stress increases, although the manipulation force reduces.

Novel in situ multiharmonic EQCM-D approach to characterize complex carbon pore architectures for capacitive deionization of brackish water

International Nuclear Information System (INIS)

Shpigel, Netanel; Levi, Mikhael D; Sigalov, Sergey; Aurbach, Doron; Daikhin, Leonid; Presser, Volker

2016-01-01

Multiharmonic analysis by electrochemical quartz-crystal microbalance with dissipation monitoring (EQCM-D) is introduced as an excellent tool for quantitative studying electrosorption of ions from aqueous solution in mesoporous (BP-880) or mixed micro-mesoporous (BP-2000) carbon electrodes. Finding the optimal conditions for gravimetric analysis of the ionic content in the charged carbon electrodes, we propose a novel approach to modeling the charge-dependent gravimetric characteristics by incorporation of Gouy-Chapman-Stern electric double layer model for ions electrosorption into meso- and micro-mesoporous carbon electrodes. All three parameters of the gravimetric equation evaluated by fitting it to the experimental mass changes curves were validated using supplementary nitrogen gas sorption analysis and complementing atomic force microscopy. Important overlap between gravimetric EQCM-D analysis of the ionic content of porous carbon electrodes and the classical capacitive deionization models has been established. The necessity and usefulness of non-gravimetric EQCM-D characterizations of complex carbon architectures, providing insight into their unique viscoelastic behavior and porous structure changes, have been discussed in detail. (paper)

Effects of a carbon price in the U.S. on economic sectors, resource use, and emissions: An input-output approach

International Nuclear Information System (INIS)

Choi, Jun-Ki; Bakshi, Bhavik R.; Haab, Timothy

2010-01-01

Despite differences in their implementation, most carbon policies aim to have similar outcomes: effectively raising the price of carbon-intensive products relative to non-carbon-intensive products. While it is possible to predict the simple broad-scale economic impacts of raising the price of carbon-intensive products-the demand for non-carbon-intensive products will increase-understanding the economic and environmental impacts of carbon policies throughout the life cycle of both types of products is more difficult. Using the example of a carbon tax, this study proposes a methodology that integrates short-term policy-induced consumer demand changes into the input-output framework to analyze the environmental and economic repercussions of a policy. Environmental repercussions include the direct and the indirect impacts on emissions, materials flow in the economy, and the reliance on various ecosystem goods and services. The approach combines economic data with data about physical flow of fossil fuels between sectors, consumption of natural resources and emissions from each sector. It applies several input-output modeling equations sequentially and uses various levels of aggregation/disaggregation. It is illustrated with the data for the 2002 U.S. economy and physical flows. The framework provides insight into the short-term complex interactions between carbon price and its economic and environmental effects.

Influencing attitudes toward carbon capture and sequestration: a social marketing approach.

Science.gov (United States)

Wong-Parodi, Gabrielle; Dowlatabadi, Hadi; McDaniels, Tim; Ray, Isha

2011-08-15

Carbon capture and sequestration (CCS), while controversial, is seen as promising because it will allow the United States to continue using its vast fossil fuel resources in a carbon-constrained world. The public is an important stakeholder in the national debate about whether or not the U.S. should include CCS as a significant part of its climate change strategy. Understanding how to effectively engage with the public about CCS has become important in recent years, as interest in the technology has intensified. We argue that engagement efforts should be focused on places where CCS will first be deployed, i.e., places with many "energy veteran" (EV) citizens. We also argue that, in addition to information on CCS, messages with emotional appeal may be necessary in order to engage the public. In this paper we take a citizen-guided social marketing approach toward understanding how to (positively or negatively) influence EV citizens' attitudes toward CCS. We develop open-ended interview protocols, and a "CCS campaign activity", for Wyoming residents from Gillette and Rock Springs. We conclude that our participants believed expert-informed CCS messages, embedded within an emotionally self-referent (ESR) framework that was relevant to Wyoming, to be more persuasive than the expert messages alone. The appeal to core values of Wyomingites played a significant role in the citizen-guided CCS messages.

An Economic Approach to Planting Trees for Carbon Storage

Science.gov (United States)

Peter J. Parks; David O. Hall; Bengt Kristrom; Omar R. Masera; Robert J. Multon; Andrew J. Plantinga; Joel N. Swisher; Jack K. Winjum

1997-01-01

Abstract: Methods are described for evaluating economic and carbon storage aspects of tree planting projects (e.g., plantations for restoration, roundwood, bioenergy, and nonwood products). Total carbon (C) stock is dynamic and comprises C in vegetation, decomposing matter, soil, products, and fuel substituted. An alternative (reference) case is...

Comparison of spatial association approaches for landscape mapping of soil organic carbon stocks

Science.gov (United States)

Miller, B. A.; Koszinski, S.; Wehrhan, M.; Sommer, M.

2015-03-01

The distribution of soil organic carbon (SOC) can be variable at small analysis scales, but consideration of its role in regional and global issues demands the mapping of large extents. There are many different strategies for mapping SOC, among which is to model the variables needed to calculate the SOC stock indirectly or to model the SOC stock directly. The purpose of this research is to compare direct and indirect approaches to mapping SOC stocks from rule-based, multiple linear regression models applied at the landscape scale via spatial association. The final products for both strategies are high-resolution maps of SOC stocks (kg m-2), covering an area of 122 km2, with accompanying maps of estimated error. For the direct modelling approach, the estimated error map was based on the internal error estimations from the model rules. For the indirect approach, the estimated error map was produced by spatially combining the error estimates of component models via standard error propagation equations. We compared these two strategies for mapping SOC stocks on the basis of the qualities of the resulting maps as well as the magnitude and distribution of the estimated error. The direct approach produced a map with less spatial variation than the map produced by the indirect approach. The increased spatial variation represented by the indirect approach improved R2 values for the topsoil and subsoil stocks. Although the indirect approach had a lower mean estimated error for the topsoil stock, the mean estimated error for the total SOC stock (topsoil + subsoil) was lower for the direct approach. For these reasons, we recommend the direct approach to modelling SOC stocks be considered a more conservative estimate of the SOC stocks' spatial distribution.

Screen printing as a scalable and low-cost approach for rigid and flexible thin-film transistors using separated carbon nanotubes.

Science.gov (United States)

Cao, Xuan; Chen, Haitian; Gu, Xiaofei; Liu, Bilu; Wang, Wenli; Cao, Yu; Wu, Fanqi; Zhou, Chongwu

2014-12-23

Semiconducting single-wall carbon nanotubes are very promising materials in printed electronics due to their excellent mechanical and electrical property, outstanding printability, and great potential for flexible electronics. Nonetheless, developing scalable and low-cost approaches for manufacturing fully printed high-performance single-wall carbon nanotube thin-film transistors remains a major challenge. Here we report that screen printing, which is a simple, scalable, and cost-effective technique, can be used to produce both rigid and flexible thin-film transistors using separated single-wall carbon nanotubes. Our fully printed top-gated nanotube thin-film transistors on rigid and flexible substrates exhibit decent performance, with mobility up to 7.67 cm2 V(-1) s(-1), on/off ratio of 10(4)∼10(5), minimal hysteresis, and low operation voltage (transistors (bent with radius of curvature down to 3 mm) and driving capability for organic light-emitting diode have been demonstrated. Given the high performance of the fully screen-printed single-wall carbon nanotube thin-film transistors, we believe screen printing stands as a low-cost, scalable, and reliable approach to manufacture high-performance nanotube thin-film transistors for application in display electronics. Moreover, this technique may be used to fabricate thin-film transistors based on other materials for large-area flexible macroelectronics, and low-cost display electronics.

Scenario-based potential effects of carbon trading in China: An integrated approach

International Nuclear Information System (INIS)

Zhang, Cheng; Wang, Qunwei; Shi, Dan; Li, Pengfei; Cai, Wanhuan

2016-01-01

Highlights: • Carbon dioxide shadow price shows a negative asymmetrical correlation with carbon dioxide emissions in China. • The implements of carbon trading can bring Porter Hypothesis effect significantly. • Provincial carbon trading can reduce carbon intensity by 19.79–25.24% in China. - Abstract: Using China’s provincial panel data and national panel data of OECD (Organization for Economic Co-operation and Development) and BRICS (Five major emerging national economies: Brazil, Russia, India, China and South Africa), this paper simulates the scenario-based potential effect of carbon trading in China. Analysis methods included Stochastic Frontier Analysis, Difference-in-differences Model, and Nonlinear Programming Technique. Results indicated that in a theory-based view of carbon trading, the shadow price of carbon dioxide generally rises, with a non-linear negative correlation with carbon dioxide emissions. In different regions, the shadow price of carbon dioxide presents a digressive tendency among eastern, central, and western areas, with divergent gaps between and within areas. When the greatest goal is assumed to reduce national carbon intensity as much as possible at the given national GDP (Gross Domestic Product) (Scenario I), carbon trading has the effect of reducing carbon intensity by 19.79%, with the consideration of Porter Hypothesis effect. If the rigid constraint of national GDP is relaxed, and the dual constraint of both economic growth and environment protection in each region is introduced (Scenario II), the resulting effect is a reduced carbon intensity of 25.24%. China’s general carbon intensity in 2012 was higher than goals set at the Copenhagen Conference, but lagged behind the goal of Twelfth Five-Year Plan for National Economy. This study provides realistic and significant technical support for the government to use in designing and deploying a national carbon trading market.

A novel approach to process carbonate samples for radiocarbon measurements with helium carrier gas

Energy Technology Data Exchange (ETDEWEB)

Wacker, L., E-mail: wacker@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Fueloep, R.-H. [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany); Hajdas, I. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Molnar, M. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Institute of Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Rethemeyer, J. [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany)

2013-01-15

Most laboratories prepare carbonates samples for radiocarbon analysis by acid decomposition in evacuated glass tubes and subsequent reduction of the evolved CO{sub 2} to graphite in self-made reduction manifolds. This process is time consuming and labor intensive. In this work, we have tested a new approach for the preparation of carbonate samples, where any high-vacuum system is avoided and helium is used as a carrier gas. The liberation of CO{sub 2} from carbonates with phosphoric acid is performed in a similar way as it is often done in stable isotope ratio mass spectrometry where CO{sub 2} is released with acid in septum sealed tube under helium atmosphere. The formed CO{sub 2} is later flushed in a helium flow by means of a double-walled needle mounted from the tubes to the zeolite trap of the automated graphitization equipment (AGE). It essentially replaces the elemental analyzer normally used for the combustion of organic samples. The process can be fully automated from sampling the released CO{sub 2} in the septum-sealed tubes with a commercially available auto-sampler to the graphitization with the automated graphitization. The new method yields in low sample blanks of about 50000 years. Results of processed reference materials (IAEA-C2, FIRI-C) are in agreement with their consensus values.

Assessing carbon lock-in

International Nuclear Information System (INIS)

Erickson, Peter; Kartha, Sivan; Lazarus, Michael; Tempest, Kevin

2015-01-01

The term ‘carbon lock-in’ refers to the tendency for certain carbon-intensive technological systems to persist over time, ‘locking out’ lower-carbon alternatives, and owing to a combination of linked technical, economic, and institutional factors. These technologies may be costly to build, but relatively inexpensive to operate and, over time, they reinforce political, market, and social factors that make it difficult to move away from, or ‘unlock’ them. As a result, by investing in assets prone to lock-in, planners and investors restrict future flexibility and increase the costs of achieving agreed climate protection goals. Here, we develop a straight-forward approach to assess the speed, strength, and scale of carbon lock-in for major energy-consuming assets in the power, buildings, industry, and transport sectors. We pilot the approach at the global level, finding that carbon lock-in is greatest, globally, for coal power plants, gas power plants, and oil-based vehicles. The approach can be readily applied at the national or regional scale, and may be of particular relevance to policymakers interested in enhancing flexibility in their jurisdictions for deeper emissions cuts in the future, and therefore in limiting the future costs associated with ‘stranded assets’. (letter)

Carbon Balance and Contribution of Harvested Wood Products in China Based on the Production Approach of the Intergovernmental Panel on Climate Change

Directory of Open Access Journals (Sweden)

Chunyi Ji

2016-11-01

Full Text Available The carbon sequestration of harvested wood products (HWP plays an important role in climate mitigation. Accounting the carbon contribution of national HWP carbon pools has been listed as one of the key topics for negotiation in the United Nations Framework Convention on Climate Change. On the basis of the revised Production Approach of the Intergovernmental Panel on Climate Change (2013 (IPCC, this study assessed the accounting of carbon stock and emissions from the HWP pool in China and then analyzed its balance and contribution to carbon mitigation from 1960 to 2014. Research results showed that the accumulated carbon stock in China’s HWP carbon pool increased from 130 Teragrams Carbon (TgC in 1960 to 705.6 TgC in 2014. The annual increment in the carbon stock rose from 3.2 TgC in 1960 to 45.2 TgC in 2014. The category of solid wood products accounted for approximately 95% of the annual amount. The reduction in carbon emissions was approximately twelve times that of the emissions from the HWP producing and processing stage during the last decade. Furthermore, the amount of carbon stock and emission reduction increased from 23 TgC in 1960 to 76.1 TgC in 2014. The annual contribution of HWP could compensate for approximately 2.9% of the national carbon dioxide emissions in China.

Carbon Balance and Contribution of Harvested Wood Products in China Based on the Production Approach of the Intergovernmental Panel on Climate Change.

Science.gov (United States)

Ji, Chunyi; Cao, Wenbin; Chen, Yong; Yang, Hongqiang

2016-11-12

The carbon sequestration of harvested wood products (HWP) plays an important role in climate mitigation. Accounting the carbon contribution of national HWP carbon pools has been listed as one of the key topics for negotiation in the United Nations Framework Convention on Climate Change. On the basis of the revised Production Approach of the Intergovernmental Panel on Climate Change (2013) (IPCC), this study assessed the accounting of carbon stock and emissions from the HWP pool in China and then analyzed its balance and contribution to carbon mitigation from 1960 to 2014. Research results showed that the accumulated carbon stock in China's HWP carbon pool increased from 130 Teragrams Carbon (TgC) in 1960 to 705.6 TgC in 2014. The annual increment in the carbon stock rose from 3.2 TgC in 1960 to 45.2 TgC in 2014. The category of solid wood products accounted for approximately 95% of the annual amount. The reduction in carbon emissions was approximately twelve times that of the emissions from the HWP producing and processing stage during the last decade. Furthermore, the amount of carbon stock and emission reduction increased from 23 TgC in 1960 to 76.1 TgC in 2014. The annual contribution of HWP could compensate for approximately 2.9% of the national carbon dioxide emissions in China.

Carbon Balance and Contribution of Harvested Wood Products in China Based on the Production Approach of the Intergovernmental Panel on Climate Change

Science.gov (United States)

Ji, Chunyi; Cao, Wenbin; Chen, Yong; Yang, Hongqiang

2016-01-01

The carbon sequestration of harvested wood products (HWP) plays an important role in climate mitigation. Accounting the carbon contribution of national HWP carbon pools has been listed as one of the key topics for negotiation in the United Nations Framework Convention on Climate Change. On the basis of the revised Production Approach of the Intergovernmental Panel on Climate Change (2013) (IPCC), this study assessed the accounting of carbon stock and emissions from the HWP pool in China and then analyzed its balance and contribution to carbon mitigation from 1960 to 2014. Research results showed that the accumulated carbon stock in China’s HWP carbon pool increased from 130 Teragrams Carbon (TgC) in 1960 to 705.6 TgC in 2014. The annual increment in the carbon stock rose from 3.2 TgC in 1960 to 45.2 TgC in 2014. The category of solid wood products accounted for approximately 95% of the annual amount. The reduction in carbon emissions was approximately twelve times that of the emissions from the HWP producing and processing stage during the last decade. Furthermore, the amount of carbon stock and emission reduction increased from 23 TgC in 1960 to 76.1 TgC in 2014. The annual contribution of HWP could compensate for approximately 2.9% of the national carbon dioxide emissions in China. PMID:27845760

A Carbon Monitoring System Approach to US Coastal Wetland Carbon Fluxes: Progress Towards a Tier II Accounting Method with Uncertainty Quantification

Science.gov (United States)

Windham-Myers, L.; Holmquist, J. R.; Bergamaschi, B. A.; Byrd, K. B.; Callaway, J.; Crooks, S.; Drexler, J. Z.; Feagin, R. A.; Ferner, M. C.; Gonneea, M. E.; Kroeger, K. D.; Megonigal, P.; Morris, J. T.; Schile, L. M.; Simard, M.; Sutton-Grier, A.; Takekawa, J.; Troxler, T.; Weller, D.; Woo, I.

2015-12-01

Despite their high rates of long-term carbon (C) sequestration when compared to upland ecosystems, coastal C accounting is only recently receiving the attention of policy makers and carbon markets. Assessing accuracy and uncertainty in net C flux estimates requires both direct and derived measurements based on both short and long term dynamics in key drivers, particularly soil accretion rates and soil organic content. We are testing the ability of remote sensing products and national scale datasets to estimate biomass and soil stocks and fluxes over a wide range of spatial and temporal scales. For example, the 2013 Wetlands Supplement to the 2006 IPCC GHG national inventory reporting guidelines requests information on development of Tier I-III reporting, which express increasing levels of detail. We report progress toward development of a Carbon Monitoring System for "blue carbon" that may be useful for IPCC reporting guidelines at Tier II levels. Our project uses a current dataset of publically available and contributed field-based measurements to validate models of changing soil C stocks, across a broad range of U.S. tidal wetland types and landuse conversions. Additionally, development of biomass algorithms for both radar and spectral datasets will be tested and used to determine the "price of precision" of different satellite products. We discuss progress in calculating Tier II estimates focusing on variation introduced by the different input datasets. These include the USFWS National Wetlands Inventory, NOAA Coastal Change Analysis Program, and combinations to calculate tidal wetland area. We also assess the use of different attributes and depths from the USDA-SSURGO database to map soil C density. Finally, we examine the relative benefit of radar, spectral and hybrid approaches to biomass mapping in tidal marshes and mangroves. While the US currently plans to report GHG emissions at a Tier I level, we argue that a Tier II analysis is possible due to national

Carbon balance assessment of a natural steppe of southern Siberia by multiple constraint approach

Directory of Open Access Journals (Sweden)

L. Belelli Marchesini

2007-08-01

Full Text Available Steppe ecosystems represent an interesting case in which the assessment of carbon balance may be performed through a cross validation of the eddy covariance measurements against ecological inventory estimates of carbon exchanges (Ehman et al., 2002; Curtis et al., 2002.

Indeed, the widespread presence of ideal conditions for the applicability of the eddy covariance technique, as vast and homogeneous grass vegetation cover over flat terrains (Baldocchi, 2003, make steppes a suitable ground to ensure a constrain to flux estimates with independent methodological approaches.

We report about the analysis of the carbon cycle of a true steppe ecosystem in southern Siberia during the growing season of 2004 in the framework of the TCOS-Siberia project activities performed by continuous monitoring of CO₂ fluxes at ecosystem scale by the eddy covariance method, fortnightly samplings of phytomass, and ingrowth cores extractions for NPP assessment, and weekly measurements of heterotrophic component of soil CO₂ effluxes obtained by an experiment of root exclusion.

The carbon balance of the monitored natural steppe was, according to micrometeorological measurements, a sink of carbon of 151.7±36.9 g C m⁻², cumulated during the growing season from May to September. This result was in agreement with the independent estimate through ecological inventory which yielded a sink of 150.1 g C m⁻² although this method was characterized by a large uncertainty (±130% considering the 95% confidence interval of the estimate. Uncertainties in belowground process estimates account for a large part of the error. Thus, in particular efforts to better quantify the dynamics of root biomass (growth and turnover have to be undertaken in order to reduce the uncertainties in the assessment of NPP. This assessment should be preferably based on the application of multiple methods, each one characterized by its

Reconciling biodiversity and carbon conservation.

Science.gov (United States)

Thomas, Chris D; Anderson, Barbara J; Moilanen, Atte; Eigenbrod, Felix; Heinemeyer, Andreas; Quaife, Tristan; Roy, David B; Gillings, Simon; Armsworth, Paul R; Gaston, Kevin J

2013-05-01

Climate change is leading to the development of land-based mitigation and adaptation strategies that are likely to have substantial impacts on global biodiversity. Of these, approaches to maintain carbon within existing natural ecosystems could have particularly large benefits for biodiversity. However, the geographical distributions of terrestrial carbon stocks and biodiversity differ. Using conservation planning analyses for the New World and Britain, we conclude that a carbon-only strategy would not be effective at conserving biodiversity, as have previous studies. Nonetheless, we find that a combined carbon-biodiversity strategy could simultaneously protect 90% of carbon stocks (relative to a carbon-only conservation strategy) and > 90% of the biodiversity (relative to a biodiversity-only strategy) in both regions. This combined approach encapsulates the principle of complementarity, whereby locations that contain different sets of species are prioritised, and hence disproportionately safeguard localised species that are not protected effectively by carbon-only strategies. It is efficient because localised species are concentrated into small parts of the terrestrial land surface, whereas carbon is somewhat more evenly distributed; and carbon stocks protected in one location are equivalent to those protected elsewhere. Efficient compromises can only be achieved when biodiversity and carbon are incorporated together within a spatial planning process. © 2012 John Wiley & Sons Ltd/CNRS.

Surface science approach to Pt/carbon model catalysts: XPS, STM and microreactor studies

Science.gov (United States)

Motin, Abdul Md.; Haunold, Thomas; Bukhtiyarov, Andrey V.; Bera, Abhijit; Rameshan, Christoph; Rupprechter, Günther

2018-05-01

Pt nanoparticles supported on carbon are an important technological catalyst. A corresponding model catalyst was prepared by physical vapor deposition (PVD) of Pt on sputtered HOPG (highly oriented pyrolytic graphite). The carbon substrate before and after sputtering as well as the Pt/HOPG system before and after Pt deposition and annealing were examined by XPS and STM. This yielded information on the surface density of defects, which serve as nucleation centres for Pt, and on the size distribution (mean size/height) of the Pt nanoparticles. Two different model catalysts were prepared with mean sizes of 2.0 and 3.6 nm, both turned out to be stable upon UHV-annealing to 300 °C. After transfer into a UHV-compatible flow microreactor and subsequent cleaning in UHV and under mbar pressure, the catalytic activity of the Pt/HOPG model system for ethylene hydrogenation was examined under atmospheric pressure flow conditions. This enabled to determine temperature-dependent conversion rates, turnover frequencies (TOFs) and activation energies. The catalytic results obtained are in line with the characteristics of technological Pt/C, demonstrating the validity of the current surface science based model catalyst approach.

Surveying and analyzing injection responses for patterns with horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Fedenczuk, L.; Hoffman, K.

1998-12-31

A novel method for visualizing injection responses in patterns that include horizontal and/or vertical wells is described. Understanding fluid communication between the horizontal well and the surrounding injectors is essential to estimating the effectiveness of the waterflood. Armed with the understanding of responses, injection patterns can be optimized, production rates can be increased and more efficient oil recovery can be achieved. In this study the time lags of correlations and a new parameter, the waterflood response type is introduced. The response type is based on the oil and total fluid responses. In addition spider diagrams are introduced to help visualizing the correlations, time lags and response types. Integration of the results with geology, petrophysics and completion techniques can help to find the cause and effect rules in waterflood fields. 6 refs., 10 figs.

Microbial enhanced oil recovery and compositions therefor

Science.gov (United States)

Bryant, Rebecca S.

1990-01-01

A method is provided for microbial enhanced oil recovery, wherein a combination of microorganisms is empirically formulated based on survivability under reservoir conditions and oil recovery efficiency, such that injection of the microbial combination may be made, in the presence of essentially only nutrient solution, directly into an injection well of an oil bearing reservoir having oil present at waterflood residual oil saturation concentration. The microbial combination is capable of displacing residual oil from reservoir rock, which oil may be recovered by waterflooding without causing plugging of the reservoir rock. Further, the microorganisms are capable of being transported through the pores of the reservoir rock between said injection well and associated production wells, during waterflooding, which results in a larger area of the reservoir being covered by the oil-mobilizing microorganisms.

Metaheuristic optimization approaches to predict shear-wave velocity from conventional well logs in sandstone and carbonate case studies

Science.gov (United States)

Emami Niri, Mohammad; Amiri Kolajoobi, Rasool; Khodaiy Arbat, Mohammad; Shahbazi Raz, Mahdi

2018-06-01

Seismic wave velocities, along with petrophysical data, provide valuable information during the exploration and development stages of oil and gas fields. The compressional-wave velocity (VP ) is acquired using conventional acoustic logging tools in many drilled wells. But the shear-wave velocity (VS ) is recorded using advanced logging tools only in a limited number of wells, mainly because of the high operational costs. In addition, laboratory measurements of seismic velocities on core samples are expensive and time consuming. So, alternative methods are often used to estimate VS . Heretofore, several empirical correlations that predict VS by using well logging measurements and petrophysical data such as VP , porosity and density are proposed. However, these empirical relations can only be used in limited cases. The use of intelligent systems and optimization algorithms are inexpensive, fast and efficient approaches for predicting VS. In this study, in addition to the widely used Greenberg–Castagna empirical method, we implement three relatively recently developed metaheuristic algorithms to construct linear and nonlinear models for predicting VS : teaching–learning based optimization, imperialist competitive and artificial bee colony algorithms. We demonstrate the applicability and performance of these algorithms to predict Vs using conventional well logs in two field data examples, a sandstone formation from an offshore oil field and a carbonate formation from an onshore oil field. We compared the estimated VS using each of the employed metaheuristic approaches with observed VS and also with those predicted by Greenberg–Castagna relations. The results indicate that, for both sandstone and carbonate case studies, all three implemented metaheuristic algorithms are more efficient and reliable than the empirical correlation to predict VS . The results also demonstrate that in both sandstone and carbonate case studies, the performance of an artificial bee

Comprehensive spectral and instrumental approaches for the easy monitoring of features and purity of different carbon nanostructures for nanocomposite applications

International Nuclear Information System (INIS)

Boccaleri, Enrico; Arrais, Aldo; Frache, Alberto; Gianelli, Walter; Fino, Paolo; Camino, Giovanni

2006-01-01

A wide series of carbon nanostructures (ranging from fullerenes, through carbon nanotubes, up to carbon nanofibers) promise to change several fields in material science, but a real industrial implementation depends on their availability at reasonable prices with affordable and reproducible degrees of purity. In this study we propose simple instrumental approaches to efficiently characterize different commercial samples, particularly for qualitative evaluation of impurities, the discrimination of their respective spectral features and, when possible, for quantitative determination. We critically discuss information that researchers in the field of nanocomposite technology can achieve in this aim by spectral techniques such as Raman and FT-IR spectroscopy, thermo-gravimetrical analysis, mass spectrometry-hyphenated thermogravimetry, X-ray diffraction and energy dispersive spectroscopy. All these can be helpful, in applied research on material science, for a fast reliable monitoring of the actual purity of carbon products in both commercial and laboratory-produced samples as well as in composite materials

The carbon cycle and global warming

International Nuclear Information System (INIS)

Anon.

1991-01-01

Five land-use-based approaches can be used to slow the buildup of CO 2 in the atmosphere: slowing or stopping the loss of existing forests, thus preserving current carbon reservoirs; adding to the planet's vegetative cover through reforestation or other means, thus enlarging living terrestrial carbon reservoirs; increasing the carbon stored in nonliving carbon reservoirs such as agricultural soils; increasing the carbon stored in artificial reservoirs, including timber products; and substituting sustainable biomass energy sources for fossil fuel consumption, thus reducing energy-related carbon emissions. These approaches are all based on the same basic premise: adding to the planet's net carbon stores in vegetative cover or soil, or preventing any net loss, will help moderate global warming by keeping atmospheric CO 2 levels lower than they would otherwise be. Because biotic policy options appear capable of contributing significantly to the mitigation of global warming while also furthering many other public policy objectives, their role deserves careful consideration on a country-by-country basis

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion

Science.gov (United States)

Overholt, David M.

1993-06-01

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications.

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion

International Nuclear Information System (INIS)

Overholt, D.M.

1993-06-01

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications. 3 refs

To Facilitate or Curb? The Role of Financial Development in China's Carbon Emissions Reduction Process: A Novel Approach.

Science.gov (United States)

Xing, Tiancai; Jiang, Qichuan; Ma, Xuejiao

2017-10-13

With the Paris Agreement coming into effect, China, as the largest CO₂ emitter in the world, will be facing greater pressure to reduce its carbon emissions. This paper discusses how to solve this issue from the perspective of financial development in China. Although many studies have analyzed its impact on carbon emissions, the conclusions are contradictory. A major criticism of the existing studies is the reasonability of the selection of appropriate indicators and panel estimation techniques. Almost all studies use only one or limited indicators to represent the financial development and ignore the cross-sectional dependence. To fulfil the gaps mentioned above, a financial development index system is built, and with the framework of the STIRPAT (Stochastic impacts by regression on population, affluence, and technology) model, this paper applies an ARDL approach to investigating the long-run relationship between financial development and carbon emissions and a dynamic panel error-corrected model to capture the short-run impact. The empirical results show that financial development can improve carbon emissions, and such impact not only shows a regional difference but also reflects the features of stage differences. Additionally, based on the discussion on seven specific aspects of financial development, our findings can be helpful for policy makers to enact corresponding policies to realize the goal of reducing carbon emissions in China.

Carbon tax effects on the poor: a SAM-based approach

Science.gov (United States)

Chapa, Joana; Ortega, Araceli

2017-09-01

A SAM-based price model for Mexico is developed in order to assess the effects of the carbon tax, which was part of the fiscal reform approved in 2014. The model is formulated based on a social accounting matrix (SAM) that distinguishes households by the official poverty condition and geographical area. The main results are that the sector that includes coke, refined petroleum and nuclear fuel shows the highest price increase due to the direct impact of the carbon tax; in addition, air transport and inland transport are the most affected sectors, in an indirect manner, because both employ inputs from the former sector. Also, it is found that welfare diminishes more in the rural strata than in the urban one. In the urban area, the carbon tax is regressive: the negative impact of carbon tax on family welfare is greater on the poorest families.

An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

NARCIS (Netherlands)

Filgueira, R.; Byron, C.J.; Comeau, L.A.; Jansen, H.M.; Smaal, A.C.

2015-01-01

The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities,

Non-covalently functionalized carbon nanostructures for synthesizing carbon-based hybrid nanomaterials.

Science.gov (United States)

Li, Haiqing; Song, Sing I; Song, Ga Young; Kim, Il

2014-02-01

Carbon nanostructures (CNSs) such as carbon nanotubes, graphene sheets, and nanodiamonds provide an important type of substrate for constructing a variety of hybrid nanomaterials. However, their intrinsic chemistry-inert surfaces make it indispensable to pre-functionalize them prior to immobilizing additional components onto their surfaces. Currently developed strategies for functionalizing CNSs include covalent and non-covalent approaches. Conventional covalent treatments often damage the structure integrity of carbon surfaces and adversely affect their physical properties. In contrast, the non-covalent approach offers a non-destructive way to modify CNSs with desired functional surfaces, while reserving their intrinsic properties. Thus far, a number of surface modifiers including aromatic compounds, small-molecular surfactants, amphiphilic polymers, and biomacromolecules have been developed to non-covalently functionalize CNS surfaces. Mediated by these surface modifiers, various functional components such as organic species and inorganic nanoparticles were further decorated onto their surfaces, resulting in versatile carbon-based hybrid nanomaterials with broad applications in chemical engineering and biomedical areas. In this review, the recent advances in the generation of such hybrid nanostructures based on non-covalently functionalized CNSs will be reviewed.

Total Belowground Carbon Allocation in a Fast-growing Eucalyptus Plantation Estimated Using a Carbon Balance Approach

Science.gov (United States)

Christian P. Giardina; Michael G. Ryan

2002-01-01

Trees allocate a large portion of gross primary production belowground for the production and maintenance of roots and mycorrhizae. The difficulty of directly measuring total belowground carbon allocation (TBCA) has limited our understanding of belowground carbon (C) cycling and the factors that control this important flux. We measured TBCA over 4 years using a...

Toward transformational carbon capture systems

Energy Technology Data Exchange (ETDEWEB)

Miller, David C. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Litynski, John T. [Office of Fossil Energy, U.S. Dept. of Energy, Washington DC (United States); Brickett, Lynn A. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Morreale, Bryan D. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States)

2015-10-28

This paper will briefly review the history and current state of Carbon Capture and Storage (CCS) research and development and describe the technical barriers to carbon capture. it will argue forcefully for a new approach to R&D, which leverages both simulation and physical systems at the laboratory and pilot scales to more rapidly move the best technoogies forward, prune less advantageous approaches, and simultaneously develop materials and processes.

Langmuir hydrogen dissociation approach in radiolabeling carbon nanotubes and graphene oxide

International Nuclear Information System (INIS)

Badun, Gennadii A.; Chernysheva, Maria G.; Eremina, Elena A.; Egorov, Alexander V.; Grigorieva, Anastasia V.

2016-01-01

Carbon-based nanomaterials have piqued the interest of several researchers. At the same time, radioactive labeling is a powerful tool for studying processes in different systems, including biological and organic; however, the introduction of radioactive isotopes into carbon-based nanomaterial remains a great challenge. We have used the Langmuir hydrogen dissociation method to introduce tritium in single-walled carbon nanotubes and graphene oxide. The technique allows us to achieve a specific radioactivity of 107 and 27 Ci/g for single-layer graphene oxide and single-walled carbon nanotubes, respectively. Based on the analysis of characteristic Raman modes at 1350 and 1580 cm -1 , a minimal amount of structural changes to the nanomaterials due to radiolabeling was observed. The availability of a simple, nondestructive, and economic technique for the introduction of radiolabels to single-walled carbon nanotubes and graphene oxide will ultimately expand the applicability of these materials.

Langmuir hydrogen dissociation approach in radiolabeling carbon nanotubes and graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Badun, Gennadii A.; Chernysheva, Maria G.; Eremina, Elena A.; Egorov, Alexander V. [Lomonosov Moscow State Univ. (Russian Federation). Dept. of Chemistry; Grigorieva, Anastasia V. [Lomonosov Moscow State Univ., Moscow (Russian Federation). Dept. of Materials Science

2016-11-01

Carbon-based nanomaterials have piqued the interest of several researchers. At the same time, radioactive labeling is a powerful tool for studying processes in different systems, including biological and organic; however, the introduction of radioactive isotopes into carbon-based nanomaterial remains a great challenge. We have used the Langmuir hydrogen dissociation method to introduce tritium in single-walled carbon nanotubes and graphene oxide. The technique allows us to achieve a specific radioactivity of 107 and 27 Ci/g for single-layer graphene oxide and single-walled carbon nanotubes, respectively. Based on the analysis of characteristic Raman modes at 1350 and 1580 cm{sup -1}, a minimal amount of structural changes to the nanomaterials due to radiolabeling was observed. The availability of a simple, nondestructive, and economic technique for the introduction of radiolabels to single-walled carbon nanotubes and graphene oxide will ultimately expand the applicability of these materials.

Looking for carbonates in the deep Earth: an experimental approach at extreme conditions

Science.gov (United States)

Chariton, S.; Bykova, E.; Bykov, M.; Cerantola, V.; Vasiukov, D.; Stekiel, M.; Aprilis, G.; Kupenko, I.; Ismailova, L.; Chumakov, A. I.; Winkler, B.; McCammon, C. A.; Dubrovinsky, L. S.

2017-12-01

There is a long list of natural and experimental evidence to support a key role for carbonates in the deep carbon cycle. As potential carriers of carbon in subducted slabs with the possibility to influence redox conditions, carbonates have deservedly been the focus of many high pressure and high temperature experimental studies over the past decade. "How long do they survive after subduction? What form do they transform to? How do they react with their surroundings?" are all important questions. We use many tools to search for carbonates in the deep Earth. Using laser heated diamond anvil cells to generate pressures and temperatures over 100 GPa and 2500 K along with the advanced technology provided by synchrotron facilities, we have been able to study in situ the behavior of various carbonate minerals at conditions of the Earth's mantle. We have particularly focused our interest on transition metal carbonates (Fe, Mn, Co, Zn, Ni)CO3 in order to study the crystal chemistry of calcite-type carbonates using single crystal X-ray diffraction and Raman spectroscopy. Our results show new high-pressure carbonate structures, including either CO3-3or CO4-4 units, that often coexist with complex metal oxides. Combined with carbonate stability fields from the surface to the lower mantle, we investigated the possibility to detect carbonates from seismic data. We determined the elastic wave velocities of plausible carbonate mineral compositions in the (Mg-Fe)CO3 system using Nuclear Inelastic Scattering. Our results show the strong anisotropic behavior of carbonates that could explain anisotropic anomalies observed at transition zone depths and confirm the presence of carbonate reservoirs. The effect of carbonate composition and Fe2+ spin transition, which is completed above 50 GPa, are also well demonstrated. More new carbonate phases and their seismic signatures await to be discovered, and thus experiments continue.

Carbon monoxide tolerant anodes for proton exchange membrane (PEM) fuel cells. 1. Catalyst development approach

Energy Technology Data Exchange (ETDEWEB)

Holleck, G L; Pasquariello, D M; Clauson, S L

1998-07-01

PEM fuel cells are highly attractive for distributed power and cogeneration systems. They are efficient and function virtually without noise or pollution. To be competitive PEM fuel cells must operate on fuel mixtures obtained by reforming of widely available natural gas or liquid hydrocarbons. Reformed fuel gas mixtures invariably contain CO, a strong poison for Pt. Therefore CO tolerant anode catalysts are essential for wide spread PEMFC introduction. It is the objective to develop effective CO tolerant fuel cell catalysts based on multi-component platinum-transition metal alloys. Towards this goal the authors have developed a novel approach for the synthesis and performance evaluation of multifunctional ternary alloy fuel cell catalysts. The alloys are prepared as well-defined thin films on standard TFE-bonded carbon substrates via a dc magnetron sputtering technique. The anodes are laminated to Nafion membranes and the electrochemical performance is measured in a representative fuel cell configuration with H{sub 2} and H{sub 2}/CO gas mixtures. The multi-target sputtering technique permits one to reproducibly synthesize true alloy films of controlled composition. The deposit morphology and electrode structure are determined by the standardized TFE bonded carbon substrate. The thin catalyst layer is concentrated at the electrode ionomer interface where it can be fully utilized in a representative fuel cell configuration. Thus, a true comparative fuel cell catalyst evaluation is possible. The effectiveness of this approach will be demonstrated with Pt, Pt-Ru and Pt-Ru-X catalyzed anodes.

A novel approach for the fabrication of carbon nanofibre/ceramic porous structures

KAUST Repository

Walter, Claudia; Barg, Suelen; Ni, Na; Maher, Robert C.; Garcίa-Tuñ ó n, Esther; Zaiviji Ismail, Muhammad Muzzafar; Babot, Flora; Saiz, Eduardo

2013-01-01

This paper describes the fabrication of hybrid ceramic/carbon scaffolds in which carbon nanofibres and multi-walled carbon nanotubes fully cover the internal walls of a microporous ceramic structure that provides mechanical stability. Freeze casting

Modeling the binding affinity of structurally diverse industrial chemicals to carbon using the artificial intelligence approaches.

Science.gov (United States)

Gupta, Shikha; Basant, Nikita; Rai, Premanjali; Singh, Kunwar P

2015-11-01

Binding affinity of chemical to carbon is an important characteristic as it finds vast industrial applications. Experimental determination of the adsorption capacity of diverse chemicals onto carbon is both time and resource intensive, and development of computational approaches has widely been advocated. In this study, artificial intelligence (AI)-based ten different qualitative and quantitative structure-property relationship (QSPR) models (MLPN, RBFN, PNN/GRNN, CCN, SVM, GEP, GMDH, SDT, DTF, DTB) were established for the prediction of the adsorption capacity of structurally diverse chemicals to activated carbon following the OECD guidelines. Structural diversity of the chemicals and nonlinear dependence in the data were evaluated using the Tanimoto similarity index and Brock-Dechert-Scheinkman statistics. The generalization and prediction abilities of the constructed models were established through rigorous internal and external validation procedures performed employing a wide series of statistical checks. In complete dataset, the qualitative models rendered classification accuracies between 97.04 and 99.93%, while the quantitative models yielded correlation (R(2)) values of 0.877-0.977 between the measured and the predicted endpoint values. The quantitative prediction accuracies for the higher molecular weight (MW) compounds (class 4) were relatively better than those for the low MW compounds. Both in the qualitative and quantitative models, the Polarizability was the most influential descriptor. Structural alerts responsible for the extreme adsorption behavior of the compounds were identified. Higher number of carbon and presence of higher halogens in a molecule rendered higher binding affinity. Proposed QSPR models performed well and outperformed the previous reports. A relatively better performance of the ensemble learning models (DTF, DTB) may be attributed to the strengths of the bagging and boosting algorithms which enhance the predictive accuracies. The

An experimental and theoretical study to relate uncommon rock/fluid properties to oil recovery. Final report

Energy Technology Data Exchange (ETDEWEB)

Watson, R.

1995-07-01

Waterflooding is the most commonly used secondary oil recovery technique. One of the requirements for understanding waterflood performance is a good knowledge of the basic properties of the reservoir rocks. This study is aimed at correlating rock-pore characteristics to oil recovery from various reservoir rock types and incorporating these properties into empirical models for Predicting oil recovery. For that reason, this report deals with the analyses and interpretation of experimental data collected from core floods and correlated against measurements of absolute permeability, porosity. wettability index, mercury porosimetry properties and irreducible water saturation. The results of the radial-core the radial-core and linear-core flow investigations and the other associated experimental analyses are presented and incorporated into empirical models to improve the predictions of oil recovery resulting from waterflooding, for sandstone and limestone reservoirs. For the radial-core case, the standardized regression model selected, based on a subset of the variables, predicted oil recovery by waterflooding with a standard deviation of 7%. For the linear-core case, separate models are developed using common, uncommon and combination of both types of rock properties. It was observed that residual oil saturation and oil recovery are better predicted with the inclusion of both common and uncommon rock/fluid properties into the predictive models.

Mesoporous Carbon Produced from Tri-constituent Mesoporous Carbon-silica Composite for Water Purification

KAUST Repository

Yu, Yanjie

2012-01-01

Highly ordered mesoporous carbon-silica nanocomposites with interpenetrating carbon and silica networks were synthesized by the evaporation-induced tri-constituent co- assembly approach. The removal of silica by concentrated NaOH solution produced mesoporous carbons, which contained not only the primary large pores, but also the secondary mesopores in the carbon walls. The thus synthesized mesoporous carbon was further activated by using ZnCl2. The activated mesoporous carbon showed an improved surface area and pore volume. The synthesized mesoporous carbon was tested for diuron removal from water and the results showed that the carbon gave a fast diuron adsorption kinetics and a high diuron removal capacity, which was attributable to the primary mesopore channels being the highway for mass transfer, which led to short diffusion path length and easy accessibility of the interpenetrated secondary mesopores. The optimal adsorption capacity of the porous carbon was determined to be 390 mg/g, the highest values ever reported for diuron adsorption on carbon-based materials.

Mesoporous Carbon Produced from Tri-constituent Mesoporous Carbon-silica Composite for Water Purification

KAUST Repository

Yu, Yanjie

2012-05-01

Highly ordered mesoporous carbon-silica nanocomposites with interpenetrating carbon and silica networks were synthesized by the evaporation-induced tri-constituent co- assembly approach. The removal of silica by concentrated NaOH solution produced mesoporous carbons, which contained not only the primary large pores, but also the secondary mesopores in the carbon walls. The thus synthesized mesoporous carbon was further activated by using ZnCl2. The activated mesoporous carbon showed an improved surface area and pore volume. The synthesized mesoporous carbon was tested for diuron removal from water and the results showed that the carbon gave a fast diuron adsorption kinetics and a high diuron removal capacity, which was attributable to the primary mesopore channels being the highway for mass transfer, which led to short diffusion path length and easy accessibility of the interpenetrated secondary mesopores. The optimal adsorption capacity of the porous carbon was determined to be 390 mg/g, the highest values ever reported for diuron adsorption on carbon-based materials.

Comparison of methods for estimating carbon in harvested wood products

International Nuclear Information System (INIS)

Claudia Dias, Ana; Louro, Margarida; Arroja, Luis; Capela, Isabel

2009-01-01

There is a great diversity of methods for estimating carbon storage in harvested wood products (HWP) and, therefore, it is extremely important to agree internationally on the methods to be used in national greenhouse gas inventories. This study compares three methods for estimating carbon accumulation in HWP: the method suggested by Winjum et al. (Winjum method), the tier 2 method proposed by the IPCC Good Practice Guidance for Land Use, Land-Use Change and Forestry (GPG LULUCF) (GPG tier 2 method) and a method consistent with GPG LULUCF tier 3 methods (GPG tier 3 method). Carbon accumulation in HWP was estimated for Portugal under three accounting approaches: stock-change, production and atmospheric-flow. The uncertainty in the estimates was also evaluated using Monte Carlo simulation. The estimates of carbon accumulation in HWP obtained with the Winjum method differed substantially from the estimates obtained with the other methods, because this method tends to overestimate carbon accumulation with the stock-change and the production approaches and tends to underestimate carbon accumulation with the atmospheric-flow approach. The estimates of carbon accumulation provided by the GPG methods were similar, but the GPG tier 3 method reported the lowest uncertainties. For the GPG methods, the atmospheric-flow approach produced the largest estimates of carbon accumulation, followed by the production approach and the stock-change approach, by this order. A sensitivity analysis showed that using the ''best'' available data on production and trade of HWP produces larger estimates of carbon accumulation than using data from the Food and Agriculture Organization. (author)

Carbon Nanotube Templated Microfabrication of Porous Silicon-Carbon Materials

Science.gov (United States)

Song, Jun; Jensen, David; Dadson, Andrew; Vail, Michael; Linford, Matthew; Vanfleet, Richard; Davis, Robert

2010-10-01

Carbon nanotube templated microfabrication (CNT-M) of porous materials is demonstrated. Partial chemical infiltration of three dimensional carbon nanotube structures with silicon resulted in a mechanically robust material, precisely structured from the 10 nm scale to the 100 micron scale. Nanoscale dimensions are determined by the diameter and spacing of the resulting silicon/carbon nanotubes while the microscale dimensions are controlled by lithographic patterning of the CNT growth catalyst. We demonstrate the utility of this hierarchical structuring approach by using CNT-M to fabricate thin layer chromatography (TLC) separations media with precise microscale channels for fluid flow control and nanoscale porosity for high analyte capacity.

A combined salt-hard templating approach for synthesis of multi-modal porous carbons used for probing the simultaneous effects of porosity and electrode engineering on EDLC performance

KAUST Repository

Bhandari, Nidhi

2015-06-01

A new approach, based on a combination of salt and hard templating for producing multi-modal porous carbons is demonstrated. The hard template, silica nanoparticles, generate mesopores (∼22 nm), and in some cases borderline-macropores (∼64 nm), resulting in high pore volume (∼3.9 cm3/g) while the salt template, zinc chloride, generates borderline-mesopores (∼2 nm), thus imparting high surface area (∼2100 m2/g). The versatility of the proposed synthesis technique is demonstrated using: (i) dual salt templates with hard template resulting in magnetic, nanostructured-clay embedded (∼27% clay content), high surface area (∼1527 m2/g) bimodal carbons (∼2 and 70 nm pores), (ii) multiple hard templates with salt template resulting in tri-modal carbons (∼2, 12 and 28 nm pores), (iii) low temperature (450 °C) synthesis of bimodal carbons afforded by the presence of hygroscopic salt template, (iv) easy coupling with physical activation approaches. A selected set of thus synthesized carbons were used to evaluate, for the first time, the simultaneous effects of carbon porosity and pressure applied during electrode fabrication on EDLC performance. Electrode pressing was found to be more favorable for carbons containing hard-templated mesopores (∼87% capacitance retention at current density of 40 A/g) as compared to those without (∼54% capacitance retention). © 2015 Elsevier Ltd. All rights reserved.

To Facilitate or Curb? The Role of Financial Development in China’s Carbon Emissions Reduction Process: A Novel Approach

Science.gov (United States)

Xing, Tiancai; Jiang, Qichuan

2017-01-01

With the Paris Agreement coming into effect, China, as the largest CO2 emitter in the world, will be facing greater pressure to reduce its carbon emissions. This paper discusses how to solve this issue from the perspective of financial development in China. Although many studies have analyzed its impact on carbon emissions, the conclusions are contradictory. A major criticism of the existing studies is the reasonability of the selection of appropriate indicators and panel estimation techniques. Almost all studies use only one or limited indicators to represent the financial development and ignore the cross-sectional dependence. To fulfil the gaps mentioned above, a financial development index system is built, and with the framework of the STIRPAT (Stochastic impacts by regression on population, affluence, and technology) model, this paper applies an ARDL approach to investigating the long-run relationship between financial development and carbon emissions and a dynamic panel error-corrected model to capture the short-run impact. The empirical results show that financial development can improve carbon emissions, and such impact not only shows a regional difference but also reflects the features of stage differences. Additionally, based on the discussion on seven specific aspects of financial development, our findings can be helpful for policy makers to enact corresponding policies to realize the goal of reducing carbon emissions in China. PMID:29027983

A cheap and non-destructive approach to increase coverage/loading of hydrophilic hydroxide on hydrophobic carbon for lightweight and high-performance supercapacitors

Science.gov (United States)

Zhang, Liuyang; Gong, Hao

2015-01-01

Carbon-based substrates offer unprecedented advantages in lightweight supercapacitors. However, it is still challenging to achieve high coverage or loading. Different from the traditional belief that a lack of defects or functional groups is the cause of poor growth on carbon-based substrates, we reckon that the major cause is the discrepancy between the hydrophilic nature of the metal oxide/hydroxide and the hydrophobic nature of carbon. To solve this incompatibility, we introduced ethanol into the precursor solution. The method to synthesize nickel copper hydroxide on carbon fiber paper employs only water and ethanol, in addition to nickel acetate and copper acetate. The results revealed good growth and tight adhesion of active materials on carbon fiber paper substrates. The specific capacitance and energy density per total weight of the active material plus substrate (carbon fiber paper, current collector) reached 770 F g−1 and 33 Wh kg−1 (1798 F g−1 and 54 Wh kg−1 per weight of the active materials), owing to the high loading of active material and the light weight of carbon fiber paper. These results signified the achievability of light, cheap and high-performance supercapacitors by an environmental-friendly approach. PMID:26643665

A cheap and non-destructive approach to increase coverage/loading of hydrophilic hydroxide on hydrophobic carbon for lightweight and high-performance supercapacitors

Science.gov (United States)

Zhang, Liuyang; Gong, Hao

2015-12-01

Carbon-based substrates offer unprecedented advantages in lightweight supercapacitors. However, it is still challenging to achieve high coverage or loading. Different from the traditional belief that a lack of defects or functional groups is the cause of poor growth on carbon-based substrates, we reckon that the major cause is the discrepancy between the hydrophilic nature of the metal oxide/hydroxide and the hydrophobic nature of carbon. To solve this incompatibility, we introduced ethanol into the precursor solution. The method to synthesize nickel copper hydroxide on carbon fiber paper employs only water and ethanol, in addition to nickel acetate and copper acetate. The results revealed good growth and tight adhesion of active materials on carbon fiber paper substrates. The specific capacitance and energy density per total weight of the active material plus substrate (carbon fiber paper, current collector) reached 770 F g-1 and 33 Wh kg-1 (1798 F g-1 and 54 Wh kg-1 per weight of the active materials), owing to the high loading of active material and the light weight of carbon fiber paper. These results signified the achievability of light, cheap and high-performance supercapacitors by an environmental-friendly approach.

Activated Carbon, Carbon Nanofiber and Carbon Nanotube Supported Molybdenum Carbide Catalysts for the Hydrodeoxygenation of Guaiacol

Directory of Open Access Journals (Sweden)

Eduardo Santillan-Jimenez

2015-03-01

Full Text Available Molybdenum carbide was supported on three types of carbon support—activated carbon; multi-walled carbon nanotubes; and carbon nanofibers—using ammonium molybdate and molybdic acid as Mo precursors. The use of activated carbon as support afforded an X-ray amorphous Mo phase, whereas crystalline molybdenum carbide phases were obtained on carbon nanofibers and, in some cases, on carbon nanotubes. When the resulting catalysts were tested in the hydrodeoxygenation (HDO of guaiacol in dodecane, catechol and phenol were obtained as the main products, although in some instances significant amounts of cyclohexane were produced. The observation of catechol in all reaction mixtures suggests that guaiacol was converted into phenol via sequential demethylation and HDO, although the simultaneous occurrence of a direct demethoxylation pathway cannot be discounted. Catalysts based on carbon nanofibers generally afforded the highest yields of phenol; notably, the only crystalline phase detected in these samples was Mo2C or Mo2C-ζ, suggesting that crystalline Mo2C is particularly selective to phenol. At 350 °C, carbon nanofiber supported Mo2C afforded near quantitative guaiacol conversion, the selectivity to phenol approaching 50%. When guaiacol HDO was performed in the presence of acetic acid and furfural, guaiacol conversion decreased, although the selectivity to both catechol and phenol was increased.

The average carbon-stock approach for small-scale CDM AR projects

Energy Technology Data Exchange (ETDEWEB)

Garcia Quijano, J.F.; Muys, B. [Katholieke Universiteit Leuven, Laboratory for Forest, Nature and Landscape Research, Leuven (Belgium); Schlamadinger, B. [Joanneum Research Forschungsgesellschaft mbH, Institute for Energy Research, Graz (Austria); Emmer, I. [Face Foundation, Arnhem (Netherlands); Somogyi, Z. [Forest Research Institute, Budapest (Hungary); Bird, D.N. [Woodrising Consulting Inc., Belfountain, Ontario (Canada)

2004-06-15

In many afforestation and reforestation (AR) projects harvesting with stand regeneration forms an integral part of the silvicultural system and satisfies local timber and/or fuelwood demand. Especially clear-cut harvesting will lead to an abrupt and significant reduction of carbon stocks. The smaller the project, the more significant the fluctuations of the carbon stocks may be. In the extreme case a small-scale project could consist of a single forest stand. In such case, all accounted carbon may be removed during a harvesting operation and the time-path of carbon stocks will typically look as in the hypothetical example presented in the report. For the aggregate of many such small-scale projects there will be a constant benefit to the atmosphere during the projects, due to averaging effects.

All-Carbon Electrode Consisting of Carbon Nanotubes on Graphite Foil for Flexible Electrochemical Applications

Directory of Open Access Journals (Sweden)

Je-Hwang Ryu

2014-03-01

Full Text Available We demonstrate the fabrication of an all-carbon electrode by plasma-enhanced chemical vapor deposition for use in flexible electrochemical applications. The electrode is composed of vertically aligned carbon nanotubes that are grown directly on a flexible graphite foil. Being all-carbon, the simple fabrication process and the excellent electrochemical characteristics present an approach through which high-performance, highly-stable and cost-effective electrochemical applications can be achieved.

Climate change : the case for a carbon tariff/tax

International Nuclear Information System (INIS)

Courchene, T.J.; Allan, J.R.

2008-01-01

Canada's ratification of the Kyoto Protocol will not adequately address the country's contribution to global climatic change. This paper proposed a 2-tier system consisting of internationally imposed carbon import tariffs combined with an equivalent domestic carbon tax. The approach was designed to engage global exporters and importers, while also involving governments and policy commitments related to emissions and cap-and-trade systems. Although a carbon tax on emissions is preferable to an opting-in approach, Canadian government has rejected carbon taxes due to the suspicion that Canadian companies will easily circumvent regulations. It is anticipated that many companies in carbon tax compliant countries will outsource production to non-compliant countries. The proposed approach required that carbon taxes will be applied to all domestically produced and consumed products, while tariffs will be levied against products from exporting firms. Outsourcing to take advantage of lax environmental policies in pollution havens will be subject to a carbon footprint tariff. The tariff will also serve to reduce the carbon content of exports. Proceeds of the tax can be used in a variety of ways to reduce greenhouse gas (GHG) emissions. It was concluded that Canada will need to supplement domestic carbon taxes with a proposed carbon import tariff. 1 fig

Heavy and light beer: a carbon isotope approach to detect C(4) carbon in beers of different origins, styles, and prices.

Science.gov (United States)

Brooks, J Renée; Buchmann, Nina; Phillips, Sue; Ehleringer, Bruce; Evans, R David; Lott, Mike; Martinelli, Luiz A; Pockman, William T; Sandquist, Darren; Sparks, Jed P; Sperry, Lynda; Williams, Dave; Ehleringer, James R

2002-10-23

The carbon isotope ratios (delta(13)C) of 160 beers from around the world ranged from -27.3 to -14.9 per thousand, primarily due to variation in the percentage of C(3) or C(4) plant carbon in the final product. Thirty-one percent of beers had a carbon signature of C(3) plants (barley, rice, etc.), whereas the remaining 69% contained some C(3)-C(4) mixture (mean of mixtures, 39 +/- 11% C(4) carbon). Use of C(4) carbon (corn, cane sugar, etc.) was not confined to beers from any particular region (Pacific Rim, Mexico, Brazil, Europe, Canada, and the United States). However, the delta(13)C of European beers indicated mostly C(3) plant carbon. In contrast, U.S. and Canadian beers contained either only C(3) or C(3)-C(4) mixtures; Brazilian, Mexican, and Pacific Rim beers were mostly C(3)-C(4) mixtures. Among different lagers, U.S.-style lagers generally contained more C(4) carbon than did imported pilsners. Among different ales, those brewed by large high-production breweries contained significant proportions of C(4) carbon, while C(4) carbon was not detected in microbrewery or home-brew ales. Furthermore, inexpensive beers generally contained more C(4) carbon than expensive beers.

A regression modeling approach for studying carbonate system variability in the northern Gulf of Alaska

Science.gov (United States)

Evans, Wiley; Mathis, Jeremy T.; Winsor, Peter; Statscewich, Hank; Whitledge, Terry E.

2013-01-01

northern Gulf of Alaska (GOA) shelf experiences carbonate system variability on seasonal and annual time scales, but little information exists to resolve higher frequency variability in this region. To resolve this variability using platforms-of-opportunity, we present multiple linear regression (MLR) models constructed from hydrographic data collected along the Northeast Pacific Global Ocean Ecosystems Dynamics (GLOBEC) Seward Line. The empirical algorithms predict dissolved inorganic carbon (DIC) and total alkalinity (TA) using observations of nitrate (NO3-), temperature, salinity and pressure from the surface to 500 m, with R2s > 0.97 and RMSE values of 11 µmol kg-1 for DIC and 9 µmol kg-1 for TA. We applied these relationships to high-resolution NO3- data sets collected during a novel 20 h glider flight and a GLOBEC mesoscale SeaSoar survey. Results from the glider flight demonstrated time/space along-isopycnal variability of aragonite saturations (Ωarag) associated with a dicothermal layer (a cold near-surface layer found in high latitude oceans) that rivaled changes seen vertically through the thermocline. The SeaSoar survey captured the uplift to aragonite saturation horizon (depth where Ωarag = 1) shoaled to a previously unseen depth in the northern GOA. This work is similar to recent studies aimed at predicting the carbonate system in continental margin settings, albeit demonstrates that a NO3--based approach can be applied to high-latitude data collected from platforms capable of high-frequency measurements.

Rewiring the Carbon Economy: Engineered Carbon Reduction Listening Day Summary Report

Energy Technology Data Exchange (ETDEWEB)

Illing, Lauren [BCS Inc., Laurel, MD (United States); Natelson, Robert [BCS Inc., Laurel, MD (United States); Resch, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Rowe, Ian [USDOE Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States). Bioenergy Technologies Office (EE-3B); Babson, David [USDOE Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States). Bioenergy Technologies Office (EE-3B)

2018-02-01

On July 8, 2017, the U.S. Department of Energy’s Bioenergy Technologies Office (BETO) sponsored the Engineered Carbon Reduction Listening Day: Advanced Strategies to Bypass Land Use for the Emerging Bioeconomy in La Jolla, California. This event explored non-photosynthetic carbon dioxide–reduction technologies, including electrocatalytic, thermocatalytic, photocatalytic, and biocatalytic approaches. BETO has summarized stakeholder input from the listening day in a summary report.

Technical Note: A novel approach to estimation of time-variable surface sources and sinks of carbon dioxide using empirical orthogonal functions and the Kalman filter

Directory of Open Access Journals (Sweden)

R. Zhuravlev

2011-10-01

Full Text Available In this work we propose an approach to solving a source estimation problem based on representation of carbon dioxide surface emissions as a linear combination of a finite number of pre-computed empirical orthogonal functions (EOFs. We used National Institute for Environmental Studies (NIES transport model for computing response functions and Kalman filter for estimating carbon dioxide emissions. Our approach produces results similar to these of other models participating in the TransCom3 experiment.

Using the EOFs we can estimate surface fluxes at higher spatial resolution, while keeping the dimensionality of the problem comparable with that in the regions approach. This also allows us to avoid potentially artificial sharp gradients in the fluxes in between pre-defined regions. EOF results generally match observations more closely given the same error structure as the traditional method.

Additionally, the proposed approach does not require additional effort of defining independent self-contained emission regions.

Application of alkaline waterflooding to a high acidity crude oil

Energy Technology Data Exchange (ETDEWEB)

Sayyouh, M.H. (King Sand Univ., Riyadh (SA). Petroleum Engineering Dept.); Abdel-Waly, A.; Osman, A. (Cairo Univ. (EG). Petroleum Engineering Dept.); Awara, A.Z. (Geisum Oil Company, Cairo (EG))

The enhanced recovery of a high acidity crude oil (South Geisum crude) by alkaline solutions is studied. Acidity, interfacial tension, and contact angle, were investigated. Displacement tests were carried out to study the effect of alkaline slug concentration, slug size, oil alkali type, temperature and viscosity on recovery. The interfacial tension between crude oil and formation water decreases with increasing alkaline concentration until a minimum, after which it increases again. Contact angle measurements indicated oil-wetting conditions that increase by the addition of alkaline solutions. At the early stages of displacement, oil recovery increases with increasing alkaline concentration until a maximum at 4% by weight NaOH concentration. Also, at such early stages, an excessive increase in alkaline concentration results in lower oil recovery. On the other hand, after the injection of many pore volumes of water, oil recovery is almost the same regardless of the alkaline concentration. Oil recovery increases with increasing alkaline slug size until a maximum at 15% PV. Sodium hydroxide slugs produce more oil recovery than sodium carbonate slugs. Oil recovery increases with increasing temperature (from 25 to 55{sup 0}C) and decreasing oil viscosity.

Carbon for sensing devices

CERN Document Server

Tagliaferro, Alberto

2015-01-01

This book reveals why carbon is playing such an increasingly prominent role as a sensing material. The various steps that transform a raw material in a sensing device are thoroughly presented and critically discussed.  The authors deal with all aspects of carbon-based sensors, starting from the various hybridization and allotropes of carbon, with specific focus on micro and nanosized carbons (e.g., carbon nanotubes, graphene) and their growth processes. The discussion then moves to the role of functionalization and the different routes to achieve it. Finally, a number of sensing applications in various fields are presented, highlighting the connection with the basic properties of the various carbon allotropes.  Readers will benefit from this book’s bottom-up approach, which starts from the local bonding in carbon solids and ends with sensing applications, linking the local hybridization of carbon atoms and its modification by functionalization to specific device performance. This book is a must-have in th...

Modelling effects of forest disturbance history on carbon balance: a deep learning approach using Landsat-time series.

Science.gov (United States)

Besnard, S.; Carvalhais, N.; Clevers, J.; Dutrieux, L.; Gans, F.; Herold, M.; Reichstein, M.; Jung, M.

2017-12-01

Forests play a crucial role in the global carbon (C) cycle, covering about 30% of the planet's terrestrial surface, accounting for 50% of plant productivity, and storing 45% of all terrestrial C. As such, forest disturbances affect the balance of terrestrial C dioxide (CO 2 ) exchange, with the potential of releasing large amounts of C into the atmosphere. Understanding and quantifying the effect of forest disturbance on terrestrial C metabolism is critical for improving forest C balance estimates and predictions. Here we combine remote sensing, climate, and eddy-covariance (EC) data to study forest land surface-atmosphere C fluxes at more than 180 sites globally. We aim to enhance understanding of C balance in forest ecosystems by capturing the ecological carry-over effect of disturbance historyon C fluxes. Our objectives are to (1) characterize forest disturbance history through the full temporal depth of the Landsat time series (LTS); and (2) to investigate lag and carry-over effects of forest dynamics and climate on ecosystem C fluxes using a data-driven recurrent neural network(RNN). The resulting data-driven model integrates carry-over effects of the system, using LTS, ecosystem productivity, and several abiotic factors. In this study, we show that our RNN algorithm is able to effectively calculate realistic seasonal, interannual, and across-site C flux variabilities based on EC, LTS, and climate data. In addition, our results demonstrate that a deep learning approach with embedded dynamic memory effects offorest dynamics is able to better capture lag and carry-over effects due to soil-vegetation feedback compared to a classic approach considering only the current condition of the ecosystem. Our study paves the way to produce accurate, high resolution carbon fluxes maps, providing morecomprehensive monitoring, mapping, and reporting of the carbon consequences of forest change globally.

Dilute Surfactant Methods for Carbonate Formations

Energy Technology Data Exchange (ETDEWEB)

Kishore K. Mohanty

2006-02-01

There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces

Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah

International Nuclear Information System (INIS)

Chidsey Jr., Thomas C.

2003-01-01

The primary objective of this project was to enhance domestic petroleum production by field demonstration and technology transfer of an advanced-oil-recovery technology in the Paradox Basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox Basin alone, and result in increased recovery of 150 to 200 million barrels (23,850,000-31,800,000 m3) of oil. This project was designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon-dioxide-(CO2-) miscible flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place within the Navajo Nation, San Juan County, Utah

Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah; ANNUAL

International Nuclear Information System (INIS)

Jr., Chidsey, Thomas C.; Allison, M. Lee

1999-01-01

The primary objective of this project is to enhance domestic petroleum production by field demonstration and technology transfer of an advanced- oil-recovery technology in the Paradox basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox basin alone, and result in increased recovery of 150 to 200 million barrels (23,850,000-31,800,000 m3) of oil. This project is designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon-dioxide-(CO2-) miscible flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place within the Navajo Nation, San Juan County, Utah

The first investigation of Wilms' tumour atomic structure-nitrogen and carbon isotopic composition as a novel biomarker for the most individual approach in cancer disease

Science.gov (United States)

Taran, Katarzyna; Frączek, Tomasz; Sikora-Szubert, Anita; Sitkiewicz, Anna; Młynarski, Wojciech; Kobos, Józef; Paneth, Piotr

2016-01-01

The paper describes a novel approach to investigating Wilms' tumour (nephroblastoma) biology at the atomic level. Isotope Ratio Mass Spectrometry (IRMS) was used to directly assess the isotope ratios of nitrogen and carbon in 84 Wilms' tumour tissue samples from 28 cases representing the histological spectrum of nephroblastoma. Marked differences in nitrogen and carbon isotope ratios were found between nephroblastoma histological types and along the course of cancer disease, with a breakout in isotope ratio of the examined elements in tumour tissue found between stages 2 and 3. Different isotopic compositions with regard to nitrogen and carbon content were observed in blastemal Wilms' tumour, with and without focal anaplasia, and in poorly- and well-differentiated epithelial nephroblastoma. This first assessment of nitrogen and carbon isotope ratio reveals the previously unknown part of Wilms' tumour biology and represents a potential novel biomarker, allowing for a highly individual approach to treating cancer. Furthermore, this method of estimating isotopic composition appears to be the most sensitive tool yet for cancer tissue evaluation, and a valuable complement to established cancer study methods with prospective clinical impact. PMID:27732932

An Artificial Intelligence Approach for Modeling and Prediction of Water Diffusion Inside a Carbon Nanotube

Science.gov (United States)

2009-01-01

Modeling of water flow in carbon nanotubes is still a challenge for the classic models of fluid dynamics. In this investigation, an adaptive-network-based fuzzy inference system (ANFIS) is presented to solve this problem. The proposed ANFIS approach can construct an input–output mapping based on both human knowledge in the form of fuzzy if-then rules and stipulated input–output data pairs. Good performance of the designed ANFIS ensures its capability as a promising tool for modeling and prediction of fluid flow at nanoscale where the continuum models of fluid dynamics tend to break down. PMID:20596382

Estimating the National Carbon Abatement Potential of City Policies: A Data- Driven Approach

Energy Technology Data Exchange (ETDEWEB)

Eric O’Shaughnessy, Jenny Heeter, David Keyser, Pieter Gagnon, and Alexandra Aznar

2016-10-01

Cities are increasingly taking actions such as building code enforcement, urban planning, and public transit expansion to reduce emissions of carbon dioxide in their communities and municipal operations. However, many cities lack the quantitative information needed to estimate policy impacts and prioritize city actions in terms of carbon abatement potential and cost effectiveness. This report fills this research gap by providing methodologies to assess the carbon abatement potential of a variety of city actions. The methodologies are applied to an energy use data set of 23,458 cities compiled for the U.S. Department of Energy’s City Energy Profile tool. The analysis estimates the national carbon abatement potential of the most commonly implemented actions in six specific policy areas. The results of this analysis suggest that, in aggregate, cities could reduce nationwide carbon emissions by about 210 million metric tons of carbon dioxide (MMT CO₂) per year in a "moderate abatement scenario" by 2035 and 480 MMT CO₂/year in a "high abatement scenario" by 2035 through these common actions typically within a city’s control in the six policy areas. The aggregate carbon abatement potential of these specific areas equates to a reduction of 3%-7% relative to 2013 U.S. emissions. At the city level, the results suggest the average city could reduce carbon emissions by 7% (moderate) to 19% (high) relative to current city-level emissions. City carbon abatement potential is sensitive to national and state policies that affect the carbon intensity of electricity and transportation. Specifically, the U.S. Clean Power Plan and further renewable energy cost reductions could reduce city carbon emissions overall, helping cities achieve their carbon reduction goals.

Central composite design approach towards optimization of flamboyant pods derived steam activated carbon for its use as heterogeneous catalyst in transesterification of Hevea brasiliensis oil

International Nuclear Information System (INIS)

Dhawane, Sumit H.; Kumar, Tarkeshwar; Halder, Gopinath

2015-01-01

Highlights: • Activated carbon was prepared from novel precursor flamboyant pods (Delonix regia). • Activation process was optimized using central composite design approach. • Prepared activated carbon at optimized condition was used as support for KOH. • Carbon based heterogeneous catalyst was used in transesterification of HBO. • Effect of catalyst loading and alcohol ratio on biodiesel yield was studied. - Abstract: The present investigation emphasises the preparation of carbon based KOH impregnated heterogeneous catalyst from flamboyant pods (Delonix regia) for the production of biodiesel from novel feedstock Hevea brasiliensis oil (HBO). Initially, carbonized char was physically activated by superheated steam and the process was optimized to study the effects of activation time and temperature by central composite design approach (CCD) using response surface methodology (RSM). Activated carbon was impregnated with KOH at four different ratios. Biodiesel production process was carried out at constant temperature 60 °C, reaction time 1 h, and 5 g of carbon based catalyst at varying quantities of catalyst loading (0.5, 2, 3.5, 5 wt%) and methanol to oil ratio (5:1–20:1). The influence of parameters on the biodiesel yield at varied condition was studied. Maximum yield of 89.3% was obtained at methanol to oil ratio 15:1 and catalyst loading 3.5 wt% and corresponding yield at same process parameters was observed to be 88.7% implying the significant activity of catalyst in reutilization. Produced biodiesel was characterized following ASTM standards. The experimental analysis confirmed that the carbonaceous catalyst developed from flamboyant pods under optimized condition is capable of transesterifying HBO into biodiesel

A thermodynamic approach to assess organic solute adsorption onto activated carbon in water

KAUST Repository

De Ridder, David J.; Verliefde, Arne R. D.; Heijman, Bas G J; Gelin, Simon; Pereira, Manuel Fernando Ribeiro; Rocha, Raquel P.; Figueiredo, José Luí s M; Amy, Gary L.; Van Dijk, Hans C.

2012-01-01

In this paper, the hydrophobicity of 13 activated carbons is determined by various methods; water vapour adsorption, immersion calorimetry, and contact angle measurements. The quantity and type of oxygen-containing groups on the activated carbon were measured and related to the methods used to measure hydrophobicity. It was found that the water-activated carbon adsorption strength (based on immersion calorimetry, contact angles) depended on both type and quantity of oxygen-containing groups, while water vapour adsorption depended only on their quantity. Activated carbon hydrophobicity measurements alone could not be related to 1-hexanol and 1,3-dichloropropene adsorption. However, a relationship was found between work of adhesion and adsorption of these solutes. The work of adhesion depends not only on activated carbon-water interaction (carbon hydrophobicity), but also on solute-water (solute hydrophobicity) and activated carbon-solute interactions. Our research shows that the work of adhesion can explain solute adsorption and includes the effect of hydrogen bond formation between solute and activated carbon. © 2012 Elsevier Ltd. All rights reserved.

A thermodynamic approach to assess organic solute adsorption onto activated carbon in water

KAUST Repository

De Ridder, David J.

2012-08-01

In this paper, the hydrophobicity of 13 activated carbons is determined by various methods; water vapour adsorption, immersion calorimetry, and contact angle measurements. The quantity and type of oxygen-containing groups on the activated carbon were measured and related to the methods used to measure hydrophobicity. It was found that the water-activated carbon adsorption strength (based on immersion calorimetry, contact angles) depended on both type and quantity of oxygen-containing groups, while water vapour adsorption depended only on their quantity. Activated carbon hydrophobicity measurements alone could not be related to 1-hexanol and 1,3-dichloropropene adsorption. However, a relationship was found between work of adhesion and adsorption of these solutes. The work of adhesion depends not only on activated carbon-water interaction (carbon hydrophobicity), but also on solute-water (solute hydrophobicity) and activated carbon-solute interactions. Our research shows that the work of adhesion can explain solute adsorption and includes the effect of hydrogen bond formation between solute and activated carbon. © 2012 Elsevier Ltd. All rights reserved.

Evaluation of the potential for reduction in well spacing of the Bakken sand pool, Court Field

Energy Technology Data Exchange (ETDEWEB)

Majcher, M.B.; Estrada, C.A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Nexen Inc., Calgary, AB (Canada); Archer, J.C. [Nexen Inc., Calgary, AB (Canada)

2005-11-01

For the past 15 years, the Court field has produced hydrocarbons from the Mississippian/Devonian middle Bakken sandstone reservoir. The formation is located in west central Saskatchewan and was deposited in a marine shelf environment and later reworked into tidally influenced sand ridges. Vertical wells and a waterflood recovery scheme have been used to produce heavy crude with an API gravity of 17. A better understanding of the reservoir behaviour is required in order to advance field development and maintain successful waterflood management. Three-dimensional seismic and well logs were used to map the structural complexity of the sand ridge. This study examined the feasibility of using production and seismic data to update and substantiate a simulation model which was used to evaluate downspace potential. Stratigraphic disparities were taken into account as discontinuous interbedded siltstones may be flow barriers that create anisotropy in the permeability zone. Grid orientation was altered to align axially with the permeability trends of the main sand ridge. This study also reviewed an earlier field simulation and generated an updated model. The potential to reduce well spacing was then identified and waterflood optimization of the middle Bakken reservoir was evaluated. It was concluded that the edges of the sand ridge and areas isolated from existing injectors have the greatest potential for infill drilling and additional water injection because of the high sinkhole density. It was noted that drilling edge regions with high oil saturations have a risk of low permeability zones, resulting in low production rates and the possibility of an ineffective waterflood scheme. Therefore, a successful waterflood in the edge zones would require injector-producer pairs in the equivalent sand facies. 4 refs., 36 figs.

The role of herbaceous crops in soil carbon and nitrogen cycles in relation to soil management . methodological approaches and innovative technologies

International Nuclear Information System (INIS)

Mohamed, M.A.A.

2010-01-01

Soil organic matter is an important pool within the total organic carbon of the planet,being equal to twice that if the atmosphere and three times the biotic one.Organic carbon sequestration in agricultural soils is therefore considered one of the most effective tools to counterbalance the emission of CO 2 from fossil fuels combustion. The role of below ground plant parts in carbon sequestration is much more difficult that of above.ground parts because of the open issues about the determination of root biometrics and root exhudates. Recent literature indicates that root biomass is probably much larger than classically believed and that root surface where exhudation occurs is also underestimated, and so is its role in the rhizosphere.The general objective of this thesis is the evaluation of carbon sequestration in sorghum as a function of soil management. A specific objective is to approach methodological problems relevant to the accurate quantification of the contribution of below ground plant structures to athmosferic carbon sequestration. This objective will be approached through a thorough review of the literature and an experimental setup with different soil management systems in relation to organic matter. In the review special attention is given to the applied tracer methods. The contribution of plant derived organic substances to the SOM turnover obtained with 13 C natural abundance is also reviewed. A related objective is the monitoring of nitrogen dynamics discriminating the contribution of organic matter applied to the soil. In addition to organic C, soil may also contain inorganic C in the form of carbonates. This is of particular relevance to dry lands because calcification and formation of secondary carbonate is an important process in arid and semi-arid regions. Consequently the largest accumulations of carbonate occur in the soils of arid and semi-arid areas. Dynamics of the inorganic carbon pool are poorly understood although it is normally quite

Optimal decisions of countries with carbon tax and carbon tariff

Directory of Open Access Journals (Sweden)

Yumei Hou

2015-05-01

Full Text Available Purpose: Reducing carbon emission has been the core problem of controlling global warming and climate deterioration recently. This paper focuses on the optimal carbon taxation policy levied by countries and the impact on firms’ optimal production decisions. Design/methodology/approach: This paper uses a two-stage game theory model to analyze the impact of carbon tariff and tax. Numerical simulation is used to supplement the theoretical analysis. Findings: Results derived from the paper indicate that the demand in an unstable market is significantly affected by environmental damage level. Carbon tariff is a policy-oriented tax while the carbon tax is a market-oriented one. Comprehensive carbon taxation policy benefit developed countries and basic policy is more suitable for developing countries. Research limitations/implications: In this research, we do not consider random demand and asymmetric information, which may not well suited the reality. Originality/value: This work provides a different perspective in analyzing the impact of carbon tax and tariff. It is the first study to consider two consuming market and the strategic game between two countries. Different international status of countries considered in the paper is also a unique point.

Synthesis of carbon nanoparticles using one step green approach and their application as mercuric ion sensor

Energy Technology Data Exchange (ETDEWEB)

Roshni, V.; Ottoor, Divya, E-mail: divya@chem.unipune.ac.in

2015-05-15

Carbon nanoparticles (CNPs) have been evolved as a promising candidate for the metal sensing applications due to their synthesis from naturally occurring and easily available non-toxic molecular precursors by green chemistry. A simple and one step procedure is reported here for the synthesis of CNPs from coconut milk by thermal pyrolysis at a temperature of 120–150 °C for 2–5 min without using any carbonizing or passivating agent. On pyrolysis the coconut oil is separated from the carbon rich residue and the residue when dissolved in water showed blue fluorescence under UV light. The CNPs produced are found to show an emission maximum at 440 nm when excited at 360 nm. Synthesis by green approach makes CNPs a promising substitute for the metal sensing applications. Series of metal ions which have a hazardous impact on the ecological system have been taken for the analysis and it is observed that the fluorescence of CNPs gets remarkably quenched by mercuric ions. Fluorescence quenching was studied using standard Stern–Volmer quenching model. Limit of detection was found to be 16.5 nM Hg{sup 2+} concentration. - Highlights: • Green and economical synthesis of carbon nanoparticles (CNPs) from naturally abundant material. • Coconut milk is used as molecular precursor, which on thermal pyrolysis at 120 °C yielded CNPs. • Highly fluorescent CNPs show an emission maxima of 440 nm when excited at 360 nm. • Application of CNPs for metal ion sensing using fluorescence quenching phenomena. • Hg{sup 2+} is most effectively sensed with a detection limit of 16.5 nM.

Synthesis of carbon nanoparticles using one step green approach and their application as mercuric ion sensor

International Nuclear Information System (INIS)

Roshni, V.; Ottoor, Divya

2015-01-01

Carbon nanoparticles (CNPs) have been evolved as a promising candidate for the metal sensing applications due to their synthesis from naturally occurring and easily available non-toxic molecular precursors by green chemistry. A simple and one step procedure is reported here for the synthesis of CNPs from coconut milk by thermal pyrolysis at a temperature of 120–150 °C for 2–5 min without using any carbonizing or passivating agent. On pyrolysis the coconut oil is separated from the carbon rich residue and the residue when dissolved in water showed blue fluorescence under UV light. The CNPs produced are found to show an emission maximum at 440 nm when excited at 360 nm. Synthesis by green approach makes CNPs a promising substitute for the metal sensing applications. Series of metal ions which have a hazardous impact on the ecological system have been taken for the analysis and it is observed that the fluorescence of CNPs gets remarkably quenched by mercuric ions. Fluorescence quenching was studied using standard Stern–Volmer quenching model. Limit of detection was found to be 16.5 nM Hg 2+ concentration. - Highlights: • Green and economical synthesis of carbon nanoparticles (CNPs) from naturally abundant material. • Coconut milk is used as molecular precursor, which on thermal pyrolysis at 120 °C yielded CNPs. • Highly fluorescent CNPs show an emission maxima of 440 nm when excited at 360 nm. • Application of CNPs for metal ion sensing using fluorescence quenching phenomena. • Hg 2+ is most effectively sensed with a detection limit of 16.5 nM

A dynamic programming approach for modeling low-carbon fuel technology adoption considering learning-by-doing effect

International Nuclear Information System (INIS)

Chen, Yuche; Zhang, Yunteng; Fan, Yueyue; Hu, Kejia; Zhao, Jianyou

2017-01-01

Highlights: • Dynamic programming method is used in transportation fuel portfolio planning. • The learning effect in new fuel technology is endogenously modeled through an experience curve. • Cellulosic biofuels play critical role in de-carbonization transport sector in near term. • The initial 3–4 billion gallons production is critical to bring down cellulosic biofuels’ cost. • Large penetration of Zero Emission Vehicles will discourage development of cellulosic biofuels. - Abstract: Promoting the adoption of low-carbon technologies in the transportation fuel portfolio is an effective strategy to mitigate greenhouse gas emissions from the transportation sector worldwide. However, as one of the most promising low-carbon fuels, cellulosic biofuel has not fully entered commercial production. Governments could provide guidance in developing cellulosic biofuel technologies, but no systematic approach has been proposed yet. We establish a dynamic programming framework for investigating time-dependent and adaptive decision-making processes to develop advanced fuel technologies. The learning-by-doing effect inherited in the technology development process is included in the framework. The proposed framework is applied in a case study to explore the most economical pathway for California to develop a solid cellulosic biofuel industry under its Low Carbon Fuel Standard. Our results show that cellulosic biofuel technology is playing a critical role in guaranteeing California’s 10% greenhouse gas emission reduction by 2020. Three to four billion gallons of cumulative production are needed to ensure that cellulosic biofuel is cost-competitive with petroleum-based fuels or conventional biofuels. Zero emission vehicle promoting policies will discourage the development of cellulosic biofuel. The proposed framework, with small adjustments, can also be applied to study new technology development in other energy sectors.

Carbon materials for H{sub 2} storage

Energy Technology Data Exchange (ETDEWEB)

Zubizarreta, L.; Arenillas, A.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2009-05-15

In this work a series of carbons with different structural and textural properties were characterised and evaluated for their application in hydrogen storage. The materials used were different types of commercial carbons: carbon fibers, carbon cloths, nanotubes, superactivated carbons, and synthetic carbons (carbon nanospheres and carbon xerogels). Their textural properties (i.e., surface area, pore size distribution, etc.) were related to their hydrogen adsorption capacities. These H{sub 2} storage capacities were evaluated by various methods (i.e., volumetric and gravimetric) at different temperatures and pressures. The differences between both methods at various operating conditions were evaluated and related to the textural properties of the carbon-based adsorbents. The results showed that temperature has a greater influence on the storage capacity of carbons than pressure. Furthermore, hydrogen storage capacity seems to be proportional to surface area, especially at 77 K. The micropore size distribution and the presence of narrow micropores also notably influence the H{sub 2} storage capacity of carbons. In contrast, morphological or structural characteristics have no influence on gravimetric storage capacity. If synthetic materials are used, the textural properties of carbon materials can be tailored for hydrogen storage. However, a larger pore volume would be needed in order to increase storage capacity. It seems very difficult approach to attain the DOE and EU targets only by physical adsorption on carbon materials. Chemical modification of carbons would seem to be a promising alternative approach in order to increase the capacities. (author)

Reactor design considerations in mineral sequestration of carbon dioxide

International Nuclear Information System (INIS)

Ityokumbul, M.T.; Chander, S.; O'Connor, William K.; Dahlin, David C.; Gerdemann, Stephen J.

2001-01-01

One of the promising approaches to lowering the anthropogenic carbon dioxide levels in the atmosphere is mineral sequestration. In this approach, the carbon dioxide reacts with alkaline earth containing silicate minerals forming magnesium and/or calcium carbonates. Mineral carbonation is a multiphase reaction process involving gas, liquid and solid phases. The effective design and scale-up of the slurry reactor for mineral carbonation will require careful delineation of the rate determining step and how it changes with the scale of the reactor. The shrinking core model was used to describe the mineral carbonation reaction. Analysis of laboratory data indicates that the transformations of olivine and serpentine are controlled by chemical reaction and diffusion through an ash layer respectively. Rate parameters for olivine and serpentine carbonation are estimated from the laboratory data

Valuing blue carbon: carbon sequestration benefits provided by the marine protected areas in Colombia.

Directory of Open Access Journals (Sweden)

Tatiana G Zarate-Barrera

Full Text Available Marine protected areas are aimed to protect and conserve key ecosystems for the provision of a number of ecosystem services that are the basis for numerous economic activities. Among the several services that these areas provide, the capacity of sequestering (capturing and storing organic carbon is a regulating service, provided mainly by mangroves and seagrasses, that gains importance as alternatives for mitigating global warming become a priority in the international agenda. The objective of this study is to value the services associated with the capture and storage of oceanic carbon, known as Blue Carbon, provided by a new network of marine protected areas in Colombia. We approach the monetary value associated to these services through the simulation of a hypothetical market for oceanic carbon. To do that, we construct a benefit function that considers the capacity of mangroves and seagrasses for capturing and storing blue carbon, and simulate scenarios for the variation of key variables such as the market carbon price, the discount rate, the natural rate of loss of the ecosystems, and the expectations about the post-Kyoto negotiations. The results indicate that the expected benefits associated to carbon capture and storage provided by these ecosystems are substantial but highly dependent on the expectations in terms of the negotiations surrounding the extension of the Kyoto Protocol and the dynamics of the carbon credit's demand and supply. We also find that the natural loss rate of these ecosystems does not seem to have a significant effect on the annual value of the benefits. This approach constitutes one of the first attempts to value blue carbon as one of the services provided by conservation.

A simplified modelling approach for quantifying tillage effects on soil carbon stocks

DEFF Research Database (Denmark)

Chatskikh, Dmitri; Hansen, Søren; Olesen, Jørgen E.

2009-01-01

Soil tillage has been shown to affect long-term changes in soil organic carbon (SOC) content in a number of field experiments. This paper presents a simplified approach for including effects of tillage in models of soil C turnover in the tilled-soil layer. We used an existing soil organic matter...... (SOM) model (CN-SIM) with standard SOC data for a homogeneous tilled layer from four long-term field experiments with conventionally tilled (CT) and no-till (NT) treatments. The SOM model was tested on data from long-term (>10 years) field trials differing in climatic conditions, soil properties......, residue management and crop rotations in Australia, Brazil, the USA and Switzerland. The C input for the treatments was estimated using data on crop rotation and residue management. The SOM model was applied for both CT and NT trials without recalibration, but incorporated a 'tillage factor' (TF) to scale...

Carbon felt and carbon fiber - A techno-economic assessment of felt electrodes for redox flow battery applications

Science.gov (United States)

Minke, Christine; Kunz, Ulrich; Turek, Thomas

2017-02-01

Carbon felt electrodes belong to the key components of redox flow batteries. The purpose of this techno-economic assessment is to uncover the production costs of PAN- and rayon-based carbon felt electrodes. Raw material costs, energy demand and the impact of processability of fiber and felt are considered. This innovative, interdisciplinary approach combines deep insights into technical, ecologic and economic aspects of carbon felt and carbon fiber production. Main results of the calculation model are mass balances, cumulative energy demands (CED) and the production costs of conventional and biogenic carbon felts supplemented by market assessments considering textile and carbon fibers.

Study of the Effect of Clay Particles on Low Salinity Water Injection in Sandstone Reservoirs

Directory of Open Access Journals (Sweden)

Sina Rezaei Gomari

2017-03-01

Full Text Available The need for optimal recovery of crude oil from sandstone and carbonate reservoirs around the world has never been greater for the petroleum industry. Water-flooding has been applied to the supplement primary depletion process or as a separate secondary recovery method. Low salinity water injection is a relatively new method that involves injecting low salinity brines at high pressure similar to conventional water-flooding techniques, in order to recover crude oil. The effectiveness of low salinity water injection in sandstone reservoirs depends on a number of parameters such as reservoir temperature, pressure, type of clay particle and salinity of injected brine. Clay particles present on reservoir rock surfaces adsorb polar components of oil and modify wettability of sandstone rocks to the oil-wet state, which is accountable for the reduced recovery rates by conventional water-flooding. The extent of wettability alteration caused by three low salinity brines on oil-wet sandstone samples containing varying clay content (15% or 30% and type of clay (kaolinite/montmorillonite were analyzed in the laboratory experiment. Contact angles of mica powder and clay mixture (kaolinite/montmorillonite modified with crude oil were measured before and after injection with three low salinity sodium chloride brines. The effect of temperature was also analyzed for each sample. The results of the experiment indicate that samples with kaolinite clay tend to produce higher contact angles than samples with montmorillonite clay when modified with crude oil. The highest degree or extent of wettability alteration from oil-wet to intermediate-wet state upon injection with low salinity brines was observed for samples injected with brine having salinity concentration of 2000 ppm. The increase in temperature tends to produce contact angles values lying in the higher end of the intermediate-wet range (75°–115° for samples treated at 50 °C, while their corresponding

A facile template approach for the synthesis of mesoporous Fe3C/Fe-N-doped carbon catalysts for efficient and durable oxygen reduction reaction

Institute of Scientific and Technical Information of China (English)

Shuai Li; Bo Li; Liang Ma; Jia Yang; Hangxun Xu

2017-01-01

Facile synthetic approaches toward the development of efficient and durable nonprecious metal catalysts for the oxygen reduction reaction (ORR) are very important for commercializing advanced electrochemical devices such as fuel cells and metal-air batteries.Here we report a novel template approach to synthesize mesoporous Fe-N-doped carbon catalysts encapsulated with Fe3C nanoparticles.In this approach,the layer-structured FeOCl was first used as a template for the synthesis of a three-dimensional polypyrrole (PPy) structure.During the removal of the FeOCl template,the Fe3+ can be absorbed by PPy and then converted into Fe3C nanoparticles and Fe-N-C sites during the pyrolyzing process.As a result,the as-prepared catalysts could exhibit superior electrocatalytic ORR performance to the commercial Pt/C catalyst in alkaline solutions.Furthermore,the Zn-air battery assembled using the mesoporous carbon catalyst as the air electrode could surpass the commercial Pt/C catalyst in terms of the power density and energy density.

Human Impacts and Management of Carbon Sources

Energy Technology Data Exchange (ETDEWEB)

Benson, S.; Edmonds, J.; Socolow, R.; Surles, T.

1999-08-20

The energy system dominates human-induced carbon flows on our planet. Globally, six billion tons of carbon are contained in the fossil fuels removed from below the ground every year. More than 90% of the carbon in fossil fuels is used for energy purposes, with carbon dioxide as the carbon product and the atmosphere as the initial destination for the carbon dioxide. Significantly affecting the carbon flows associated with fossil fuels is an immense undertaking. Four principal technological approaches are available to affect these carbon flows: (1) Fossil fuels and other energy resources can be utilized more efficiently; (2) Energy sources other than fossil fuels can be used; (3) Carbon dioxide from the combustion of fossil fuels can be trapped and redirected, preventing it from reaching the atmosphere (fossil carbon sequestration); and (4) One can work outside the energy system to remove carbon dioxide biologically from the atmosphere (biological carbon sequestration). An optimum carbon management strategy will surely implement all four approaches and a wise R&D program will have vigorous sub-programs in all four areas. These programs can be effective by integrating scenario analyses into the planning process. A number of future scenarios must be evaluated to determine the need for the new technologies in a future energy mix. This planning activity must be an iterative process. At present, R&D in the first two areas--energy efficiency and non-fossil fuel energy resources--is relatively well developed. By contrast, R&D in the third and the fourth areas--the two carbon sequestration options--is less well developed. The task before the workshop was to recommend ways to initiate a vigorous carbon sequestration research program without compromising the strength of the current programs in the first two areas. We recommend that this task be fulfilled by initiating several new programs in parallel. First, we recommend that a vigorous carbon sequestration program be launched

A novel approach for the fabrication of carbon nanofibre/ceramic porous structures

KAUST Repository

Walter, Claudia

2013-11-01

This paper describes the fabrication of hybrid ceramic/carbon scaffolds in which carbon nanofibres and multi-walled carbon nanotubes fully cover the internal walls of a microporous ceramic structure that provides mechanical stability. Freeze casting is used to fabricate a porous, lamellar ceramic (Al2O3) structure with aligned pores whose width can be controlled between 10 and 90μm. Subsequently, a two step chemical vapour deposition process that uses iron as a catalyst is used to grow the carbon nanostructures inside the scaffold. This catalyst remains in the scaffold after the growth process. The formation of the alumina scaffold and the influence of its structure on the growth of nanofibres and tubes are investigated. A set of growth conditions is determined to produce a dense covering of the internal walls of the porous ceramic with the carbon nanostructures. The limiting pore size for this process is located around 25μm. © 2013 Elsevier Ltd.

Carbon footprint evaluation at industrial park level: A hybrid life cycle assessment approach

International Nuclear Information System (INIS)

Dong, Huijuan; Geng, Yong; Xi, Fengming; Fujita, Tsuyoshi

2013-01-01

Industrial parks have become the effective strategies for government to promote sustainable economic development due to the following advantages: shared infrastructure and concentrated industrial activities within planned areas. However, due to intensive energy consumption and dependence on fossil fuels, industrial parks have become the main areas for greenhouse gas emissions. Therefore, it is critical to quantify their carbon footprints so that appropriate emission reduction policies can be raised. The objective of this paper is to seek an appropriate method on evaluating the carbon footprint of one industrial park. The tiered hybrid LCA method was selected due to its advantages over other methods. Shenyang Economic and Technological Development Zone (SETDZ), a typical comprehensive industrial park in China, was chosen as a case study park. The results show that the total life cycle carbon footprint of SETDZ was 15.29 Mt, including 6.81 Mt onsite (direct) carbon footprint, 8.47 Mt upstream carbon footprint, and only 3201 t downstream carbon footprint. Analysis from industrial sector perspectives shows that chemical industry and manufacture of general purpose machinery and special purposes machinery sector were the two largest sectors for life cycle carbon footprint. Such a sector analysis may be useful for investigation of appropriate emission reduction policies. - Highlights: ► A hybrid LCA model was employed to calculate industrial park carbon footprint. ► A case study on SETDZ is done. ► Life cycle carbon footprint of SETDZ is 15.29 Mt. ► Upstream and onsite carbon footprints account for 55.40% and 44.57%, respectively. ► Chemical industry and machinery manufacturing sectors are the two largest sectors

Tendances Carbone no. 74 'The Timing Impact Approach: How particularities of carbon markets influence market developments'

International Nuclear Information System (INIS)

Ruf, Philipp

2012-01-01

Among the publications of CDC Climat Research, 'Tendances Carbone' bulletin specifically studies the developments of the European market for CO 2 allowances. This issue addresses the following points: With the current 'back-loading' proposal of the European Commission on the table it is essential to further examine the specialities of carbon markets to assess the implications of the proposal on the market development of the EU ETS. An emission right is a new kind of good which can be thought of as a hybrid of a commodity good and a financial product

Carbon dioxide, climate and the deep ocean circulation: Carbon chemistry model

International Nuclear Information System (INIS)

Menawat, A.S.

1992-01-01

The objective of this study was to investigate the role of oceanic carbon chemistry in modulating the atmospheric levels of CO 2 . It is well known that the oceans are the primary sink of the excess carbon pumped into the atmosphere since the beginning of the industrial period. The suspended particulate and the dissolved organic matters in the deep ocean play important roles as carriers of carbon and other elements critical to the fate of CO 2 . In addition, the suspended particulate matter provides sites for oxidation-reduction reactions and microbial activities. The problem is of an intricate system with complex chemical, physical and biological processes. This report describes a methodology to describe the interconversions of different forms of the organic and inorganic nutrients, that may be incorporated in the ocean circulation models. Our approach includes the driving force behind the transfers in addition to balancing the elements. Such thermodynamic considerations of describing the imbalance in the chemical potentials is a new and unique feature of our approach

Carbon storage in HWP. Accounting for Spanish particleboard and fiberboard

Directory of Open Access Journals (Sweden)

Genoveva G. Canals-Revilla

2014-08-01

Full Text Available Aim of study: The study quantifies carbon stock in particleboard and fibreboard, for the period 1990-2006. It is the first accounting made for the Spanish wood industry using industrial accurate data and it could be comparable to other European studies.Area of study: SpainMaterial and Methods: A comparison of the three different approaches (Stock Change Approach, Production Approach, Atmospheric Flow Approach of the 2006 Intergovernmental Panel on Climate Change Guidelines for National Greenhouse Gas (GHG. Due to the complexity derived from the amount of input variables and the recurrence of the formulas, the Montecarlo simulation method was chosen to compare results.Main results: Between 1990-2006 the carbon stock of the Spanish panel industry has been growing steadily, reaching around 1,000 Gg C in all three approaches studied. During the period 1990-2002, the Stock Change Approach is the one which provides a higher carbon stock accounting. However, since 2002 the Production Approach is the one which presents higher values of carbon stock.Research highlights: The main result of the study shows the important role of carbon stock which play the Spanish wood based panel industry during the period analysed. The results highlight the economic and environmental importance of carbon stock stored in such wood products, as well as its remarkable increase during the study period. They also highlights the importance of good practices such as cascade use of wood resources as well as the need for properly coordination between climate change and forest policies.Key words: climate change; emissions trading system; national greenhouse gas inventories; approach; Monte Carlo; recycled wood; cascade use.

High-resolution mapping of forest carbon stocks in the Colombian Amazon

Directory of Open Access Journals (Sweden)

G. P. Asner

2012-07-01

Full Text Available High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implementation of large-scale carbon retention and enhancement programs. Previous high-resolution approaches have relied on field plot and/or light detection and ranging (LiDAR samples of aboveground carbon density, which are typically upscaled to larger geographic areas using stratification maps. Such efforts often rely on detailed vegetation maps to stratify the region for sampling, but existing tropical forest maps are often too coarse and field plots too sparse for high-resolution carbon assessments. We developed a top-down approach for high-resolution carbon mapping in a 16.5 million ha region (> 40% of the Colombian Amazon – a remote landscape seldom documented. We report on three advances for large-scale carbon mapping: (i employing a universal approach to airborne LiDAR-calibration with limited field data; (ii quantifying environmental controls over carbon densities; and (iii developing stratification- and regression-based approaches for scaling up to regions outside of LiDAR coverage. We found that carbon stocks are predicted by a combination of satellite-derived elevation, fractional canopy cover and terrain ruggedness, allowing upscaling of the LiDAR samples to the full 16.5 million ha region. LiDAR-derived carbon maps have 14% uncertainty at 1 ha resolution, and the regional map based on stratification has 28% uncertainty in any given hectare. High-resolution approaches with quantifiable pixel-scale uncertainties will provide the most confidence for monitoring changes in tropical forest carbon stocks. Improved confidence will allow resource managers and decision makers to more rapidly and effectively implement actions that better conserve and utilize forests in tropical regions.

Evaluation of approaches focused on modelling of organic carbon stocks using the RothC model

Science.gov (United States)

Koco, Štefan; Skalský, Rastislav; Makovníková, Jarmila; Tarasovičová, Zuzana; Barančíková, Gabriela

2014-05-01

The aim of current efforts in the European area is the protection of soil organic matter, which is included in all relevant documents related to the protection of soil. The use of modelling of organic carbon stocks for anticipated climate change, respectively for land management can significantly help in short and long-term forecasting of the state of soil organic matter. RothC model can be applied in the time period of several years to centuries and has been tested in long-term experiments within a large range of soil types and climatic conditions in Europe. For the initialization of the RothC model, knowledge about the carbon pool sizes is essential. Pool size characterization can be obtained from equilibrium model runs, but this approach is time consuming and tedious, especially for larger scale simulations. Due to this complexity we search for new possibilities how to simplify and accelerate this process. The paper presents a comparison of two approaches for SOC stocks modelling in the same area. The modelling has been carried out on the basis of unique input of land use, management and soil data for each simulation unit separately. We modeled 1617 simulation units of 1x1 km grid on the territory of agroclimatic region Žitný ostrov in the southwest of Slovakia. The first approach represents the creation of groups of simulation units based on the evaluation of results for simulation unit with similar input values. The groups were created after the testing and validation of modelling results for individual simulation units with results of modelling the average values of inputs for the whole group. Tests of equilibrium model for interval in the range 5 t.ha-1 from initial SOC stock showed minimal differences in results comparing with result for average value of whole interval. Management inputs data from plant residues and farmyard manure for modelling of carbon turnover were also the same for more simulation units. Combining these groups (intervals of initial

Hot atom chemistry of carbon

International Nuclear Information System (INIS)

Wolf, A.P.

1975-01-01

The chemistry of energetic carbon atoms is discussed. The experimental approach to studies that have been carried out is described and the mechanistic framework of hot carbon atom reactions is considered in some detail. Finally, the direction that future work might take is examined, including the relationship of experimental to theoretical work. (author)

A facile approach for the synthesis of monolithic hierarchical porous carbons – high performance materials for amine based CO2 capture and supercapacitor electrode

KAUST Repository

Estevez, Luis; Dua, Rubal; Bhandari, Nidhi; Ramanujapuram, Anirudh; Wang, Peng; Giannelis, Emmanuel P.

2013-01-01

An ice templating coupled with hard templating and physical activation approach is reported for the synthesis of hierarchically porous carbon monoliths with tunable porosities across all three length scales (macro- meso- and micro), with ultrahigh

Determinants and Characteristics of Korean Companies’ Carbon Management under the Carbon Pricing Scheme

Directory of Open Access Journals (Sweden)

Sunhee Suk

2018-04-01

Full Text Available In response to the domestic emission trading scheme, Korean companies are required to shift their strategies from voluntary or regulation-driven management approaches to innovative carbon management utilizing their carbon option linked with economic value. Using a questionnaire survey targeting companies subjected to the emission trading scheme, this study explores the status of Korean companies’ carbon management in a series of five strategies and identifies the correlation between companies’ proactive carbon strategies and pre-listed determinant factors. This study found that Korean companies’ practices in accordance with carbon pricing deviate little from conventional energy and environmental management in this phase. They are likely to be affected by the need to appear socially responsible or to make a social contribution, without having to exceed this mandate in terms activities outside of this remit. Yet, only a small proportion of companies have advanced to the stage of proactive carbon management. For them, top managers’ support and understanding are essential factors together with government pressure to factor-in issues related to carbon with their business strategies. This study provides implications for policy and corporate in promoting carbon-oriented management under the carbon policy.

A bio-based, facile approach for the preparation of covalently functionalized carbon nanotubes aqueous suspensions and their potential as heat transfer fluids.

Science.gov (United States)

Sadri, Rad; Hosseini, Maryam; Kazi, S N; Bagheri, Samira; Zubir, Nashrul; Solangi, K H; Zaharinie, Tuan; Badarudin, A

2017-10-15

In this study, we propose an innovative, bio-based, environmentally friendly approach for the covalent functionalization of multi-walled carbon nanotubes using clove buds. This approach is innovative because we do not use toxic and hazardous acids which are typically used in common carbon nanomaterial functionalization procedures. The MWCNTs are functionalized in one pot using a free radical grafting reaction. The clove-functionalized MWCNTs (CMWCNTs) are then dispersed in distilled water (DI water), producing a highly stable CMWCNT aqueous suspension. The CMWCNTs are characterized using Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The electrostatic interactions between the CMWCNT colloidal particles in DI water are verified via zeta potential measurements. UV-vis spectroscopy is also used to examine the stability of the CMWCNTs in the base fluid. The thermo-physical properties of the CMWCNT nano-fluids are examined experimentally and indeed, this nano-fluid shows remarkably improved thermo-physical properties, indicating its superb potential for various thermal applications. Copyright © 2017. Published by Elsevier Inc.

Building carbon-carbon bonds using a biocatalytic methanol condensation cycle.

Science.gov (United States)

Bogorad, Igor W; Chen, Chang-Ting; Theisen, Matthew K; Wu, Tung-Yun; Schlenz, Alicia R; Lam, Albert T; Liao, James C

2014-11-11

Methanol is an important intermediate in the utilization of natural gas for synthesizing other feedstock chemicals. Typically, chemical approaches for building C-C bonds from methanol require high temperature and pressure. Biological conversion of methanol to longer carbon chain compounds is feasible; however, the natural biological pathways for methanol utilization involve carbon dioxide loss or ATP expenditure. Here we demonstrated a biocatalytic pathway, termed the methanol condensation cycle (MCC), by combining the nonoxidative glycolysis with the ribulose monophosphate pathway to convert methanol to higher-chain alcohols or other acetyl-CoA derivatives using enzymatic reactions in a carbon-conserved and ATP-independent system. We investigated the robustness of MCC and identified operational regions. We confirmed that the pathway forms a catalytic cycle through (13)C-carbon labeling. With a cell-free system, we demonstrated the conversion of methanol to ethanol or n-butanol. The high carbon efficiency and low operating temperature are attractive for transforming natural gas-derived methanol to longer-chain liquid fuels and other chemical derivatives.

Integration approach for developing a high-performance biointerface: Sequential formation of hydroxyapatite and calcium carbonate by an improved alternate soaking process

International Nuclear Information System (INIS)

Watanabe, Junji; Akashi, Mitsuru

2008-01-01

Biointerfaces are crucial for regulating biofunctions. An effective method of producing new biomaterials is surface modification, in particular, the hybrid organic-inorganic approach. In this paper, we propose a method for the sequential formation of hydroxyapatite and calcium carbonate on porous polyester membranes by using an improved alternate soaking process. The resulting hybrid membranes were characterized in terms of their calcium and phosphorus ion contents; further, their structure was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (IR). As a typical biofunction, protein adsorption by these hybrid membranes was investigated. Sequential hydroxyapatite and calcium carbonate formation on the membranes was successfully achieved, and the total amounts of hydroxyapatite and calcium carbonate formed were precisely regulated by the preparative conditions. The SEM and XRD characterizations were verified by comparing with the IR results. The amount of adsorbed protein correlated well with not only the amount of hydroxyapatite formed but also the combined amounts of hydroxyapatite and calcium carbonate formed. The results indicate that the hybrid membranes can function as high-performance biointerfaces that are capable of loading biomolecules such as proteins

Spatially explicit analysis of field inventories for national forest carbon monitoring

Directory of Open Access Journals (Sweden)

David C. Marvin

2016-06-01

Full Text Available Abstract Background Tropical forests provide a crucial carbon sink for a sizable portion of annual global CO2 emissions. Policies that incentivize tropical forest conservation by monetizing forest carbon ultimately depend on accurate estimates of national carbon stocks, which are often based on field inventory sampling. As an exercise to understand the limitations of field inventory sampling, we tested whether two common field-plot sampling approaches could accurately estimate carbon stocks across approximately 76 million ha of Perúvian forests. A 1-ha resolution LiDAR-based map of carbon stocks was used as a model of the country’s carbon geography. Results Both field inventory sampling approaches worked well in estimating total national carbon stocks, almost always falling within 10 % of the model national total. However, the sampling approaches were unable to produce accurate spatially-explicit estimates of the carbon geography of Perú, with estimates falling within 10 % of the model carbon geography across no more than 44 % of the country. We did not find any associations between carbon stock errors from the field plot estimates and six different environmental variables. Conclusions Field inventory plot sampling does not provide accurate carbon geography for a tropical country with wide ranging environmental gradients such as Perú. The lack of association between estimated carbon errors and environmental variables suggests field inventory sampling results from other nations would not differ from those reported here. Tropical forest nations should understand the risks associated with primarily field-based sampling approaches, and consider alternatives leading to more effective forest conservation and climate change mitigation.

Total organic carbon, an important tool in an holistic approach to hydrocarbon source fingerprinting

Energy Technology Data Exchange (ETDEWEB)

Boehm, P.D.; Burns, W.A.; Page, D.S.; Bence, A.E.; Mankiewicz, P.J.; Brown, J.S.; Douglas, G.S. [Battelle Member Inst., Waltham, MA (United States)

2002-07-01

The identification and allocation of multiple hydrocarbon sources in marine sediments is best achieved using an holistic approach. Total organic carbon (TOC) is one important tool that can constrain the contributions of specific sources and rule out incorrect source allocations in cases where inputs are dominated by fossil organic carbon. In a study of the benthic sediments from Prince William Sound (PWS) and the Gulf of Alaska (GOA), we find excellent agreement between measured TOC and TOC calculated from hydrocarbon fingerprint matches of polycyclic aromatic hydrocarbons (PAH) and chemical biomarkers. Confirmation by two such independent source indicators (TOC and fingerprint matches) provides evidence that source allocations determined by the fingerprint matches are robust and that the major TOC sources have been correctly identified. Fingerprint matches quantify the hydrocarbon contributions of various sources to the benthic sediments and the degree of hydrocarbon winnowing by waves and currents. TOC contents are then calculated using source allocation results from fingerprint matches and the TOCs of contributing sources. Comparisons of the actual sediment TOC values and those calculated from source allocation support our earlier published findings that the natural petrogenic hydrocarbon background in sediments in this area comes from eroding Tertiary shales and associated oil seeps along the northern GOA coast and exclude thermally mature area coals from being important contributors to the PWS background due to their high TOC content.

The PTRC : a world leader in enhanced heavy oil recovery

Energy Technology Data Exchange (ETDEWEB)

Kristoff, B.; Knudsen, R.; Asghari, K. [Petroleum Technology Research Centre, Regina, SK (Canada); Pappas, E.S. [Saskatchewan Research Council, Saskatoon, SK (Canada)

2006-07-01

The Petroleum Technology Research Centre (PTRC) fosters knowledge and progressive technologies to enhance the recovery of petroleum. This paper discussed the PTRC's leadership in enhanced heavy oil recovery, with particular reference to core research program such as heavy oil (post) cold flow; enhanced waterflooding; miscible/immiscible solvent injection; and near-wellbore conformance control. Other projects that were presented included a joint implementation of vapour extraction project (JIVE); and the IEA greenhouse gas (GHG) Weyburn-Midale carbon dioxide monitoring and storage project. The JIVE project will develop, demonstrate and evaluate solvent vapour extraction processes for enhanced oil recovery in heavy oil reservoirs. The GHG Weyburn-Midale project, launched in 2000, studies carbon dioxide injection and storage in partially depleted oil reservoirs. It was concluded that the PTRC continues to develop technologies to meet the world's energy requirements while mitigating both immediate and long-term environmental impacts. 4 figs.

A statistical approach to the study of concrete carbonation

Directory of Open Access Journals (Sweden)

Garcia-Lodeiro, I.

2014-03-01

Full Text Available Carbonation is one of the factors that conditions reinforced concrete durability, while porosity is one of the parameters that determines the carbonation rate: as a rule, the greater the porosity, the higher the rate. While many papers have been published on the effect of CO2 penetration in the pore solutions of concretes prepared under different experimental conditions, the literature has yet to address the joint effect of the factors considered in concrete design, such as the water/cement (w/c ratio, type of cement, type of aggregate and presence of admixtures. The present paper discusses the findings of a statistical study of the impact of the aforementioned factors on both system porosity and carbonation rate. The type of cement, individually and in its interaction with the rest of the factors, proved to be the major determinant in concrete carbonation.La carbonatación es uno de los factores que supedita la durabilidad del hormigón armado, siendo la porosidad uno de los parámetros que más condicionan la velocidad de carbonatación. Son muchos los trabajos que estudian el efecto de la penetración del CO2 en la solución de los poros de hormigones preparados bajo distintas condiciones experimentales, sin embargo, no se encuentran referencias que analicen de forma conjunta el efecto de ciertos factores como son la relación agua/cemento (a/c ratio, el tipo de cemento, el tipo de árido y la presencia de aditivos, normalmente consideradas a la hora de diseñar un hormigón. En este trabajo se discuten los resultados obtenidos tras realizar un estudio estadístico del efecto que tienen los factores previamente mencionados, tanto en la porosidad de estos sistemas como en su nivel de carbonatación. El cemento tanto de manera individual como en sus interacciones con el resto de los factores es el factor que mas afecta a la carbonatación del hormigón.

Complexing Agents on Carbon Content and Lithium Storage Capacity of LiFePO4/C Cathode Synthesized via Sol-Gel Approach

Directory of Open Access Journals (Sweden)

C. Guan

2016-01-01

Full Text Available Olivine-structured LiFePO4 faces its intrinsic challenges in terms of poor electrical conductivity and lithium-ion diffusion capability for application to lithium-ion batteries. Cost-effective sol-gel approach is advantageous to in situ synthesize carbon-coated LiFePO4 (LiFePO4/C which can not only improve electronic conductivity but also constrain particle size to nanometer scale. In this study, the key parameter is focused on the choice and amount of chelating agents in this synthesis route. It was found that stability of complexing compounds has significant impacts on the carbon contents and electrochemical properties of the products. At the favorable choice of precursors, composition, and synthesis conditions, nanocrystalline LiFePO4/C materials with appropriate amount of carbon coating were successfully obtained. A reversible capacity of 162 mAh/g was achieved at 0.2C rate, in addition to good discharge rate capability.

The NASA Carbon Monitoring System

Science.gov (United States)

Hurtt, G. C.

2015-12-01

Greenhouse gas emission inventories, forest carbon sequestration programs (e.g., Reducing Emissions from Deforestation and Forest Degradation (REDD and REDD+), cap-and-trade systems, self-reporting programs, and their associated monitoring, reporting and verification (MRV) frameworks depend upon data that are accurate, systematic, practical, and transparent. A sustained, observationally-driven carbon monitoring system using remote sensing data has the potential to significantly improve the relevant carbon cycle information base for the U.S. and world. Initiated in 2010, NASA's Carbon Monitoring System (CMS) project is prototyping and conducting pilot studies to evaluate technological approaches and methodologies to meet carbon monitoring and reporting requirements for multiple users and over multiple scales of interest. NASA's approach emphasizes exploitation of the satellite remote sensing resources, computational capabilities, scientific knowledge, airborne science capabilities, and end-to-end system expertise that are major strengths of the NASA Earth Science program. Through user engagement activities, the NASA CMS project is taking specific actions to be responsive to the needs of stakeholders working to improve carbon MRV frameworks. The first phase of NASA CMS projects focused on developing products for U.S. biomass/carbon stocks and global carbon fluxes, and on scoping studies to identify stakeholders and explore other potential carbon products. The second phase built upon these initial efforts, with a large expansion in prototyping activities across a diversity of systems, scales, and regions, including research focused on prototype MRV systems and utilization of COTS technologies. Priorities for the future include: 1) utilizing future satellite sensors, 2) prototyping with commercial off-the-shelf technology, 3) expanding the range of prototyping activities, 4) rigorous evaluation, uncertainty quantification, and error characterization, 5) stakeholder

Economic approach to assess the forest carbon implications of biomass energy.

Science.gov (United States)

Daigneault, Adam; Sohngen, Brent; Sedjo, Roger

2012-06-05

There is widespread concern that biomass energy policy that promotes forests as a supply source will cause net carbon emissions. Most of the analyses that have been done to date, however, are biological, ignoring the effects of market adaptations through substitution, net imports, and timber investments. This paper uses a dynamic model of forest and land use management to estimate the impact of United States energy policies that emphasize the utilization of forest biomass on global timber production and carbon stocks over the next 50 years. We show that when market factors are included in the analysis, expanded demand for biomass energy increases timber prices and harvests, but reduces net global carbon emissions because higher wood prices lead to new investments in forest stocks. Estimates are sensitive to assumptions about whether harvest residues and new forestland can be used for biomass energy and the demand for biomass. Restricting biomass energy to being sourced only from roundwood on existing forestland can transform the policy from a net sink to a net source of emissions. These results illustrate the importance of capturing market adjustments and a large geographic scope when measuring the carbon implications of biomass energy policies.

Radiation Effects in Carbon Nanoelectronics

Directory of Open Access Journals (Sweden)

Cory D. Cress

2012-07-01

Full Text Available We experimentally investigate the effects of Co-60 irradiation on the electrical properties of single-walled carbon nanotube and graphene field-effect transistors. We observe significant differences in the radiation response of devices depending on their irradiation environment, and confirm that, under controlled conditions, standard dielectric hardening approaches are applicable to carbon nanoelectronics devices.

Low carbon development. Key issues

Energy Technology Data Exchange (ETDEWEB)

Urban, Frauke; Nordensvaard, Johan (eds.)

2013-03-07

This comprehensive textbook addresses the interface between international development and climate change in a carbon constrained world. It discusses the key conceptual, empirical and policy-related issues of low carbon development and takes an international and interdisciplinary approach to the subject by drawing on insights from across the natural sciences and social sciences whilst embedding the discussion in a global context. The first part explores the concept of low carbon development and explains the need for low carbon development in a carbon constrained world. The book then discusses the key issues of socio-economic, political and technological nature for low carbon development, exploring topics such as the political economy, social justice, financing and carbon markets, and technologies and innovation for low carbon development. This is followed by key issues for low carbon development in policy and practice, which is presented based on cross-cutting issues such as low carbon energy, forestry, agriculture and transportation. Afterwards, practical case studies are discussed from low carbon development in low income countries in Africa, middle income countries in Asia and Latin America and high income countries in Europe and North America.

International Emissions Trading and Induced Carbon-Saving Technical Change : Effects of Restricting the Trade in Carbon Rights

OpenAIRE

Matschoss, Patrick; Welsch, Heinz

2004-01-01

This paper examines the implications of restricting the tradability of carbon rights in the presence of induced technical change. Unlike earlier approaches aiming at exploring the tradability-technology linkage we focus on climate-relevant 'carbon-saving' technical change. This is achieved by incorporating endogenous investment in carbon productivity into the RICE-99 integrated assessment model of Nordhaus and Boyer (2000). Simulation analysis of various emission reduction scenarios with seve...

Evaluating the effects of terrestrial ecosystems, climate and carbon dioxide on weathering over geological time: a global-scale process-based approach

Science.gov (United States)

Taylor, Lyla L.; Banwart, Steve A.; Valdes, Paul J.; Leake, Jonathan R.; Beerling, David J.

2012-01-01

Global weathering of calcium and magnesium silicate rocks provides the long-term sink for atmospheric carbon dioxide (CO2) on a timescale of millions of years by causing precipitation of calcium carbonates on the seafloor. Catchment-scale field studies consistently indicate that vegetation increases silicate rock weathering, but incorporating the effects of trees and fungal symbionts into geochemical carbon cycle models has relied upon simple empirical scaling functions. Here, we describe the development and application of a process-based approach to deriving quantitative estimates of weathering by plant roots, associated symbiotic mycorrhizal fungi and climate. Our approach accounts for the influence of terrestrial primary productivity via nutrient uptake on soil chemistry and mineral weathering, driven by simulations using a dynamic global vegetation model coupled to an ocean–atmosphere general circulation model of the Earth's climate. The strategy is successfully validated against observations of weathering in watersheds around the world, indicating that it may have some utility when extrapolated into the past. When applied to a suite of six global simulations from 215 to 50 Ma, we find significantly larger effects over the past 220 Myr relative to the present day. Vegetation and mycorrhizal fungi enhanced climate-driven weathering by a factor of up to 2. Overall, we demonstrate a more realistic process-based treatment of plant fungal–geosphere interactions at the global scale, which constitutes a first step towards developing ‘next-generation’ geochemical models. PMID:22232768

Liberating energy from carbon introduction to decarbonization

CERN Document Server

Muradov, Nazim

2014-01-01

Liberating Energy from Carbon analyzes energy options in a carbon-constrained world. Major strategies and pathways to decarbonizing the carbon-intensive economy are laid out with a special emphasis on the prospects of achieving low-risk atmospheric CO2 levels. The opportunities and challenges in developing and bringing to market novel low and zero-carbon technologies are highlighted from technical, economic and environmental viewpoints. This book takes a unique approach by treating carbon in a holistic manner?tracking its complete transformation chain from fossil fuel sources to the unique pro

Estimating the National Carbon Abatement Potential of City Policies: A Data-Driven Approach

Energy Technology Data Exchange (ETDEWEB)

O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heeter, Jenny [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gagnon, Pieter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Aznar, Alexandra [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-10-01

Cities are increasingly taking actions such as building code enforcement, urban planning, and public transit expansion to reduce emissions of carbon dioxide in their communities and municipal operations. However, many cities lack the quantitative information needed to estimate policy impacts and prioritize city actions in terms of carbon abatement potential and cost effectiveness. This report fills this research gap by providing methodologies to assess the carbon abatement potential of a variety of city actions. The methodologies are applied to an energy use data set of 23,458 cities compiled for the U.S. Department of Energy City Energy Profile tool. The analysis develops a national estimate of the carbon abatement potential of realizable city actions in six specific policy areas encompassing the most commonly implemented city actions. The results of this analysis suggest that, in aggregate, cities could reduce nationwide carbon emissions by about 210 million metric tons of carbon dioxide (MMT CO2) per year in a 'moderate abatement scenario' by 2035 and 480 MMT CO2/year in a 'high abatement scenario' by 2035 through these common actions typically within a city's control in the six policy areas. The aggregate carbon abatement potential of these specific areas equates to a reduction of 3%-7% relative to 2013 U.S. emissions. At the city level, the results suggest the average city could reduce carbon emissions by 7% (moderate) to 19% (high) relative to current city-level emissions. In the context of U.S. climate commitments under the 21st session of the Conference of the Parties (COP21), the estimated national abatement potential of the city actions analyzed in this report equates to about 15%-35% of the remaining carbon abatement necessary to achieve the U.S. COP21 target. Additional city actions outside the scope of this report, such as community choice aggregation (city-level purchasing of renewable energy), zero energy districts, and multi

Black carbon sequestration as an alternative to bioenergy

International Nuclear Information System (INIS)

Fowles, Malcolm

2007-01-01

Most policy and much research concerning the application of biomass to reduce global warming gas emissions has concentrated either on increasing the Earth's reservoir of biomass or on substituting biomass for fossil fuels, with or without CO 2 sequestration. Suggested approaches entail varied risks of impermanence, delay, high costs, and unknowable side-effects. An under-researched alternative approach is to extract from biomass black (elemental) carbon, which can be permanently sequestered as mineral geomass and may be relatively advantageous in terms of those risks. This paper reviews salient features of black carbon sequestration and uses a high-level quantitative model to compare the approach with the alternative use of biomass to displace fossil fuels. Black carbon has been demonstrated to produce significant benefits when sequestered in agricultural soil, apparently without bad side-effects. Black carbon sequestration appears to be more efficient in general than energy generation, in terms of atmospheric carbon saved per unit of biomass; an exception is where biomass can efficiently displace coal-fired generation. Black carbon sequestration can reasonably be expected to be relatively quick and cheap to apply due to its short value chain and known technology. However, the model is sensitive to several input variables, whose values depend heavily on local conditions. Because characteristics of black carbon sequestration are only known from limited geographical contexts, its worldwide potential will not be known without multiple streams of research, replicated in other contexts. (author)

Thickening agent for flood water in secondary recovery of oil and for other aqueous salt solutions

Energy Technology Data Exchange (ETDEWEB)

Roth, H H

1966-04-14

Alkenyl-aromatic polymer sulfonates are good thickeners for some aqueous solutions, but addition of salts to such solutions reduces the desirable viscosity. High-molecular, water-soluble alkenyl-aromatic polymers which carry sulfonic acid or sulfonate groups substituted at the aromatic nuclei yield thickened solutions (e.g., for waterflooding) which are not influenced by the presence of water-soluble salts. Such polymers are derivatives of polyvinyltoluene, alone or in combination with about 5% acrylonitrile. It was also found that such thickening agents are less adsorbed on the rock matrix in a waterflood formation. (1 claim)

The causal nexus between carbon dioxide emissions and agricultural ecosystem-an econometric approach.

Science.gov (United States)

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2017-01-01

Achieving a long-term food security and preventing hunger include a better nutrition through sustainable systems of production, distribution, and consumption. Nonetheless, the quest for an alternative to increasing global food supply to meet the growing demand has led to the use of poor agricultural practices that promote climate change. Given the contribution of the agricultural ecosystem towards greenhouse gas (GHG) emissions, this study investigated the causal nexus between carbon dioxide emissions and agricultural ecosystem by employing a data spanning from 1961 to 2012. Evidence from long-run elasticity shows that a 1 % increase in the area of rice paddy harvested will increase carbon dioxide emissions by 1.49 %, a 1 % increase in biomass-burned crop residues will increase carbon dioxide emissions by 1.00 %, a 1 % increase in cereal production will increase carbon dioxide emissions by 1.38 %, and a 1 % increase in agricultural machinery will decrease carbon dioxide emissions by 0.09 % in the long run. There was a bidirectional causality between carbon dioxide emissions, cereal production, and biomass-burned crop residues. The Granger causality shows that the agricultural ecosystem in Ghana is sensitive to climate change vulnerability.

Experimental studies of low salinity water flooding in carbonate reservoirs: A new promising approach

DEFF Research Database (Denmark)

Zahid, Adeel; Shapiro, Alexander; Skauge, Arne

2012-01-01

Low salinity water flooding is well studied for sandstone reservoirs, both laboratory and field tests have showed improvement in the oil recovery in many cases. Up to very recently, the low salinity effect has been indeterminated for carbonates. Most recently, Saudi Aramco reported that substantial...... additional oil recovery can be achieved when successively flooding composite carbonate core plugs with various diluted versions of seawater. The experimental data on carbonates is very limited, so more data and better understanding of the mechanisms involved is needed to utilize this method for carbonate...... reservoirs. In this paper, we have experimentally investigated the oil recovery potential of low salinity water flooding for carbonate rocks. We used both reservoir carbonate and outcrop chalk core plugs. The flooding experiments were carried out initially with the seawater, and afterwards additional oil...

The Role of Eucalyptus Globulus Forest and Products in Carbon Sequestration

International Nuclear Information System (INIS)

Arroja, L.; Dias, A.C.; Capela, I.

2006-01-01

This study is a contribution to the ongoing debate about the selection of the approach for carbon accounting in wood products to be used, in the future, in the national greenhouse gas inventories under the UNFCCC (United Nations Framework Convention on Climate Change). Two accounting approaches are used in this analysis: the stock-change approach and the atmospheric-flow approach. They are applied to the Portuguese Eucalyptus globulus forest sector. To achieve this objective, the fluxes of wood removed from the forest are tracked through its life cycle, which includes products manufacture (mainly pulp and paper), use and final disposal (landfilling, incineration and composting). This study develops a framework to the estimation of carbon sequestration in the forest of E. globulus, a fast growing species, more specifically, in the calculation of the conversion factors such as bark and foliage percentages and densities, used to convert wood volumes into total biomass. A mass balance approach based on real data from mills is also proposed, in order to assess carbon emissions from wood processing. The results show that E. globulus forest sector was a carbon sink, but the magnitude of the carbon sequestration differs substantially depending on the accounting approach used. The contribution of the forest ecosystem was smaller than the aggregated contribution of wood products in use and in landfills (including industrial waste), which reinforces the role that wood products play in national carbon budgets

Geologic Carbon Sequestration Leakage Detection: A Physics-Guided Machine Learning Approach

Science.gov (United States)

Lin, Y.; Harp, D. R.; Chen, B.; Pawar, R.

2017-12-01

One of the risks of large-scale geologic carbon sequestration is the potential migration of fluids out of the storage formations. Accurate and fast detection of this fluids migration is not only important but also challenging, due to the large subsurface uncertainty and complex governing physics. Traditional leakage detection and monitoring techniques rely on geophysical observations including pressure. However, the resulting accuracy of these methods is limited because of indirect information they provide requiring expert interpretation, therefore yielding in-accurate estimates of leakage rates and locations. In this work, we develop a novel machine-learning technique based on support vector regression to effectively and efficiently predict the leakage locations and leakage rates based on limited number of pressure observations. Compared to the conventional data-driven approaches, which can be usually seem as a "black box" procedure, we develop a physics-guided machine learning method to incorporate the governing physics into the learning procedure. To validate the performance of our proposed leakage detection method, we employ our method to both 2D and 3D synthetic subsurface models. Our novel CO2 leakage detection method has shown high detection accuracy in the example problems.

[Carbon footprint of buildings in the urban agglomeration of central Liaoning, China].

Science.gov (United States)

Shi, Yu; Yun, Ying Xia; Liu, Chong; Chu, Ya Qi

2017-06-18

With the development of urbanization in China, buildings consumed lots of material and energy. How to estimate carbon emission of buildings is an important scientific problem. Carbon footprint of the central Liaoning agglomeration was studied with carbon footprint approach, geographic information system (GIS) and high-resolution remote sensing (HRRS) technology. The results showed that the construction carbon footprint coefficient of central Liaoning urban agglomeration was 269.16 kg·m -2 . The approach of interpreting total building area and spatial distribution with HRRS was effective, and the accuracy was 89%. The extraction approach was critical for total carbon footprint and spatial distribution estimation. The building area and total carbon footprint of central Liaoning urban agglomeration in descending order was Shenyang, Anshan, Fushun, Liao-yang, Yingkou, Tieling and Benxi. The annual average increment of footprint from 2011 to 2013 in descending order was Shenyang, Benxi, Fushun, Anshan, Tieling, Yingkou and Liaoyang. The accurate estimation of construction carbon footprint spatial and its distribution was of significance for the planning and optimization of carbon emission reduction.

Fluorescently labeled bionanotransporters of nucleic acid based on carbon nanotubes

International Nuclear Information System (INIS)

Novopashina, D.S.; Apartsin, E.K.; Venyaminova, A.G.

2012-01-01

We propose an approach to the design of a new type of hybrids of oligonucleotides with fluorescein-functionalized single-walled carbon nanotubes. The approach is based on stacking interactions of functionalized nanotubes with pyrene residues in conjugates of oligonucleotides. The amino- and fluorescein-modified single walled carbon nanotubes are obtained, and their physico-chemical properties are investigated. The effect of the functionalization type of carbon nanotubes on the efficacy of the sorption of pyrene conjugates of oligonucleotides was examined. The proposed noncovalent hybrids of fluorescein-labeled carbon nanotubes with oligonucleotides may be used for the intracellular transport of functional nucleic acids.

Performance analysis of irreversible molten carbonate fuel cell – Braysson heat engine with ecological objective approach

International Nuclear Information System (INIS)

Açıkkalp, Emin

2017-01-01

Highlights: • An irreversible MCFC - Braysson heat engine is considered. • Its performance is investigated with ecological approach. • A new ecological criteria are presented called as modified ecological function. • Result are obtained numerically and discussed. - Abstract: An irreversible hybrid molten carbonate fuel cell-Braysson heat engine is taken into account. Basic thermodynamics parameters including power output, efficiency and exergy destruction rate are considered. In addition ecological function and new criteria, which is based on ecological function, for heat engines called as modified ecological function is suggested. Optimum conditions for mentioned parameters above are determined. Numerical results are obtained and plotted. Finally, results are discussed.

Development of Sulfur and Carbon Tolerant Reforming Alloy Catalysts Aided Fundamental Atomistic Insights

Energy Technology Data Exchange (ETDEWEB)

Suljo Linic

2008-12-31

Current hydrocarbon reforming catalysts suffer from rapid carbon and sulfur poisoning. Even though there is a tremendous incentive to develop more efficient catalysts, these materials are currently formulated using inefficient trial and error experimental approaches. We have utilized a hybrid experimental/theoretical approach, combining quantum Density Functional Theory (DFT) calculations and various state-of-the-art experimental tools, to formulate carbon tolerant reforming catalysts. We have employed DFT calculations to develop molecular insights into the elementary chemical transformations that lead to carbon poisoning of Ni catalysts. Based on the obtained molecular insights, we have identified, using DFT quantum calculation, various Ni alloy catalysts as potential carbon tolerant reforming catalysts. The alloy catalysts were synthesized and tested in steam reforming and partial oxidation of methane, propane, and isooctane. We demonstrated that the alloy catalysts are much more carbon-tolerant than monometallic Ni catalysts under nearly stoichiometric steam-to-carbon ratios. Under these conditions, monometallic Ni is rapidly poisoned by sp2 carbon deposits. The research approach is distinguished by two characteristics: (a) knowledge-based, bottomup approach, compared to the traditional trial and error approach, allows for a more efficient and systematic discovery of improved catalysts. (b) the focus is on exploring alloy materials which have been largely unexplored as potential reforming catalysts.

Configuration of Materially Retained Carbon in Our Society: A WIO-MFA-Based Approach for Japan.

Science.gov (United States)

Ohno, Hajime; Sato, Hirokazu; Fukushima, Yasuhiro

2018-04-03

To achieve the goals of Paris Agreement, global society is directing much effort in substantially reducing greenhouse gas (GHG) emissions. In addition to energy-related efforts, prevention of carbon release into the atmosphere with carbon capture and storage (CCS) and/or utilization of biomass resources is considered indispensable to achieving the global objective. In this study, considering carbon-containing goods as carbon reservoirs in our society similar to forests and reservoirs enabling CCS, the flow of materially utilized carbon was quantified by input-output-based material flow analysis (IO-MFA). As a result, in 2011, 6.3 Mt-C of petroleum-derived carbon and 7.9 Mt-C of wood-derived carbon were introduced to the Japanese society as end-use products (e.g., automobiles and constructions) in various forms (e.g., plastics and synthetic rubbers). The total amount (14.2 Mt-C) corresponded to 4.1% (52.1 Mt-CO 2 ) of annual CO 2 emission in Japan in 2011. Subsequently, by referring to the technology that can treat carbon in the target forms in end-of-life products, the recoverability of carbon as a material has been discussed with respect to each form and end-use of carbon. By numerically showing the necessity and potential of implementing appropriate technologies, this study provides scientific direction for policymakers to establish a quality carbon cycle in our society.

Carbon cycle makeover

DEFF Research Database (Denmark)

Canfield, Donald Eugene; Kump, Lee R.

2013-01-01

remaining in sediments after respiration leave a residual of oxygen in the atmosphere. The source of oxygen to the atmosphere represented by organic matter burial is balanced by oxygen sinks associated with rock weathering and chemical reaction with volcanic gases. This is the long-term carbon and oxygen...... geochemical cycle. But Earth is an old planet, and oxygen levels have changed through time (2). On page 540 of this issue, Schrag et al. (3) challenge the most commonly used geochemical approach to assess long-term changes in the coupled oxygen and carbon cycles....

Thermodynamic Cconstraints on Coupled Carbonate-Pyrite Weathering Dynamics and Carbon Fluxes

Science.gov (United States)

Winnick, M.; Maher, K.

2017-12-01

Chemical weathering within the critical zone regulates global biogeochemical cycles, atmospheric composition, and the supply of key nutrients to terrestrial and aquatic ecosystems. Recent studies suggest that thermodynamic limits on solute production act as a first-order control on global chemical weathering rates; however, few studies have addressed the factors that set these thermodynamic limits in natural systems. In this presentation, we investigate the effects of soil CO2 concentrations and pyrite oxidation rates on carbonate dissolution and associated carbon fluxes in the East River watershed in Colorado, using concentration-discharge relationships and thermodynamic constraints. Within the shallow subsurface, soil respiration rates and moisture content determine the extent of carbonic acid-promoted carbonate dissolution through their modulation of soil pCO2 and the balance of open- v. closed-system weathering processes. At greater depths, pyrite oxidation generates sulfuric acid, which alters the approach to equilibrium of infiltrating waters. Through comparisons of concentration-discharge data and reactive transport model simulations, we explore the conditions that determine whether sulfuric acid reacts to dissolve additional carbonate mineral or instead reacts with alkalinity already in solution - the balance of which determines watershed carbon flux budgets. Our study highlights the importance of interactions between the chemical structure of the critical zone and the hydrologic regulation of flowpaths in determining concentration-discharge relationships and overall carbon fluxes.

Evaluation of the Committed Carbon Emissions and Global Warming due to the Permafrost Carbon Feedback

Science.gov (United States)

Elshorbany, Y. F.; Schaefer, K. M.; Jafarov, E. E.; Yumashev, D.; Hope, C.

2017-12-01

We quantify the increase in carbon emissions and temperature due to Permafrost Carbon feedback (PCF), defined as the amplification of anthropogenic warming due to carbon emissions from thawing permafrost (i.e., of near-surface layers to 3 m depth). We simulate the Committed PCF emissions, the cumulative total emissions from thawing permafrost by 2300 for a given global temperature increase by 2100, and investigate the resulting global warming using the Simple Biosphere/Carnegie-Ames-Stanford Approach SiBCASA model. We estimate the committed PCF emissions and warming for the Fifth Assessment Report, Representative Concentration Pathway scenarios 4.5 and 8.5 using two ensembles of five projections. For the 2 °C warming target of the global climate change treaty, committed PCF emissions increase to 24 Gt C by 2100 and 76 Gt C by 2300 and the committed PCF warming is 0.23 °C by 2300. Our calculations show that as the global temperature increase by 2100 approaches 5.8 °C, the entire stock of frozen carbon thaws out, resulting in maximum committed PCF emissions of 560 Gt C by 2300.

Enhancement in photoluminescence performance of carbon-decorated T-ZnO

International Nuclear Information System (INIS)

Jian, Xian; Chen, Guozhang; Wang, Chao; Yin, Liangjun; Yang, Ping; Chen, Lei; Xu, Bao; Gao, Yang; Feng, Yanyu; Tang, Hui; Luan, Chunhong; Liang, Yinglin; Jiang, Jing; Cao, Yu; Wang, Siyuan; Gao, Xin; Li, Gang

2015-01-01

The facile preparation of ZnO possessing high visible luminescence intensity remains challenging due to an unclear luminescence mechanism. Here, two basic approaches are proposed to enhance the luminescent intensity based on the theoretical analysis over surface defects. Based on the deduction, we introduce a methodology for obtaining hybrid tetrapod-like zinc oxide (T-ZnO), decorated by carbon nanomaterials on T-ZnO surfaces through the catalytic chemical vapor deposition approach. The intensity of the T-ZnO green emission can be modulated by topography and the proportion of carbon. Under proper experiment conditions, the carbon decorating leads to dramatically enhanced luminescence intensity of T-ZnO from 400 to 700 nm compared with no carbon decorated, which elevates this approach to a simple and effective method for the betterment of fluorescent materials in practical applications. (paper)

Flood offers new hope for marginal oil fields

Energy Technology Data Exchange (ETDEWEB)

1966-03-14

The economics of producing a marginal Cardium sand oil field in west-central Alberta have been greatly improved by introduction of an inexpensive waterflood pressure maintenance and secondary recovery project. Canadian Gridoil Ltd. is now in full operation at its Willesden Green Cardium Unit No. 5. Of the 8.1 million bbl estimated original oil in place, only 9% would have been recoverable by primary depletion. The waterflood is calculated to add 13%, for ultimate recovery of 22% or 1.8 million bbl. This waterflood installation is considered a prototype of economical and profitable pressure maintenance systems which can be built to advantage in marginal oil fields in Alberta. Ultimate returns in the form of increased oil production and more than doubled oil recovery will be immensely greater than the capital investment of $195,000 in the facilities. Assuming GOR control and full well allowables, the entire capital cost should be paid out within 3 years. Life of the field is estimated at not less than 25 years.

A modelling approach to estimate carbon emissions from D.R.C. deforestation

Science.gov (United States)

Najdovski, Nicolas; Poulter, Benjamin; Defourny, Pierre; Moreau, Inès; Maignan, Fabienne; Ciais, Philippe; Verhegghen, Astrid; Kibambe Lubamba, Jean-Paul; Jungers, Quentin; De Weirdt, Marjolein; Verbeeck, Hans; MacBean, Natasha; Peylin, Philippe

2014-05-01

With its 1.8 million squared kilometres, the Congo basin dense forest represents the second largest contiguous forest of the world. These extensive forest ecosystems play a significant role in the regulation of global climate by their potential carbon dioxide emissions and carbon storage. Under a stable climate, the vegetation, assumed to be at the equilibrium, is known to present neutral emissions over a year with seasonal variations. However, modifications in temperatures, precipitations, CO2 atmospheric concentrations have the potential to modify this balance leading to higher or lower biomass storage. In addition, deforestation and forest degradation have played a significant role over the past several decades and are expected to become increasingly important in the future. Here, we quantify the relative effects of deforestation and 21st century climate change on carbon emissions in Congo Basin over the next three decades (2005-2035). Carbon dioxide emissions are estimated using a series of moderate resolution (10 km) vegetation maps merged with spatially explicit deforestation projections and developed to work with a prognostic carbon cycle model. The inversion of the deforestation model allowed hindcast land-use patterns back to 1800 by using land cover change rates based on the HYDE database. Simulations were made over the Democratic Republic of Congo (DRC) using the ORCHIDEE dynamic global vegetation model with climate forcing from the CMIP5 Representative Concentration Pathway 8.5 scenario for the HadGEM2. Two simulations were made, a reference simulation with land cover fixed at 2005 and a land cover change simulation with changing climate and CO2, to quantify the net land cover change emissions and climate emissions directly. Because of the relatively high resolution of the model simulations, the spatial patterns of human-driven carbon losses can be tracked in the context of climate change, providing information for mitigation and vulnerability

A novel dendrochronological approach reveals drivers of carbon sequestration in tree species of riparian forests across spatiotemporal scales.

Science.gov (United States)

Rieger, Isaak; Kowarik, Ingo; Cherubini, Paolo; Cierjacks, Arne

2017-01-01

Aboveground carbon (C) sequestration in trees is important in global C dynamics, but reliable techniques for its modeling in highly productive and heterogeneous ecosystems are limited. We applied an extended dendrochronological approach to disentangle the functioning of drivers from the atmosphere (temperature, precipitation), the lithosphere (sedimentation rate), the hydrosphere (groundwater table, river water level fluctuation), the biosphere (tree characteristics), and the anthroposphere (dike construction). Carbon sequestration in aboveground biomass of riparian Quercus robur L. and Fraxinus excelsior L. was modeled (1) over time using boosted regression tree analysis (BRT) on cross-datable trees characterized by equal annual growth ring patterns and (2) across space using a subsequent classification and regression tree analysis (CART) on cross-datable and not cross-datable trees. While C sequestration of cross-datable Q. robur responded to precipitation and temperature, cross-datable F. excelsior also responded to a low Danube river water level. However, CART revealed that C sequestration over time is governed by tree height and parameters that vary over space (magnitude of fluctuation in the groundwater table, vertical distance to mean river water level, and longitudinal distance to upstream end of the study area). Thus, a uniform response to climatic drivers of aboveground C sequestration in Q. robur was only detectable in trees of an intermediate height class and in taller trees (>21.8m) on sites where the groundwater table fluctuated little (≤0.9m). The detection of climatic drivers and the river water level in F. excelsior depended on sites at lower altitudes above the mean river water level (≤2.7m) and along a less dynamic downstream section of the study area. Our approach indicates unexploited opportunities of understanding the interplay of different environmental drivers in aboveground C sequestration. Results may support species-specific and

Growth and field emission properties of one-dimensional carbon composite structure consisting of vertically aligned carbon nanotubes and nanocones

International Nuclear Information System (INIS)

Zhang Hongxin; Feng, Peter X; Fonseca, Luis; Morell, Gerardo; Makarov, Vladimir I; Weiner, Brad R

2009-01-01

A simple approach is demonstrated for quickly growing a large-area aligned carbon composite nanostructure consisting of vertically aligned nanotubes and nanocones by the catalyst-assisted pulsed laser deposition techniques. The pyrolytic graphite was used as carbon source. The carbon nanocones were first grown on the molybdenum substrate with Ni catalysts. The carbon nanotubes have a uniform shape and length, aligned vertically on carbon nanocones, and the average diameter is about 7 nm. The special carbon composite arrays exhibit excellent field emission behaviours. The long-term field emission current stability of the one-dimensioned carbon nanostructure has also been investigated. No obvious current density decay was observed after a 10-day continuous experiment, indicating the super stability of the sample as cathode material.

Structural evolution of Eucalyptus tar pitch-based carbons during carbonization

International Nuclear Information System (INIS)

Prauchner, Marcos J.; Pasa, Vanya M.D.; Molhallem, Nelcy D.S.; Otani, Choyu; Otani, Satika; Pardini, Luiz C.

2005-01-01

Wood tar pitches are generated as by-products by the charcoal manufacturing industry. They have a macromolecular structure constituted mainly by phenolic, guaiacylic, and siringylic units common to lignin. Due to their characteristics, biopitches are been investigated as precursors of carbon materials such as carbon fibers, bioelectrodes and activated carbons. In the present work the structural evolution of Eucalyptus tar pitches under carbonization is investigated, which is important for the improvement of planning and control of pitch processing and end-product properties during carbon material production. The studies involve X-ray diffraction and infrared analyses, besides helium density, BET surface area and BJH pore volume measurements. The results showed that the conversion of pitch into carbon basically involves three steps: (1) Up to around 600 deg C the material has an highly disordered structure, being the release of aliphatic side chains and volatiles the main events taking place. (2) Between 600 deg C and 800 deg C, condensation of aromatic rings occurs to form bi-dimensional hexagonal networks so that micro- and mesoporosity are developed. The 800 deg C-coke is constituted by two phases: one highly disordered and another more crystalline. (3) Over 800 deg C, both phases are gradually ordered. As defects are gradually removed, surface area and porosity decrease, approaching zero for the 2100 deg C-coke

Playing with the figures of climate: an approach with carbon budget

International Nuclear Information System (INIS)

Treiner, J.

2015-01-01

The possibility of limiting the increase of the average earth atmospheric temperature to 2 Celsius degrees appears to belong to the past. Rich countries have succeeded in blocking or even reducing their emissions of greenhouse effect gases but they still rely heavily on fossil energies. As for developing countries their development is essentially based on fossil energies they use in a growing tendency. It is difficult to image how these trends could be reversed in a short time. In the article the carbon budget is defined as the cumulated quantity of carbon that will avoid exceeding a fixed value of temperature. For instance a 2 degrees increase of temperature correspond to a CO_2 concentration in the atmosphere of 450 ppm. In the case where nothing was done and that fossil energies were used until their exhaustion, the carbon budget would reach 657 ppm and the corresponding increase of temperature would be beyond 4 degrees. (A.C.)

GIS based approach for atmospheric carbon absorption strategies through forests development in Indian situations

International Nuclear Information System (INIS)

Yadav, Surendra Kumar

2013-01-01

Geographical information system (GIS) play important role in forest management. An effective strategy for enhancement of atmospheric carbon absorption productivity is through forests development in degraded forest areas and waste lands. Forestry sector has significant emissions removal capability which can further be enhanced by operationalizing major afforestation and reforestation initiatives like National Mission for a Green India besides continued strengthening of the present protection regime of forests. Secondary data was collected and analyzed. Different types of waste lands require different strategies for their development into forest areas; but few waste lands like rocky regions, glacier regions etc. cannot be developed into forest areas. Atmospheric carbon management is major problem before world community in present circumstances to control environmental pollution. Various forest ecosystems play significant role in carbon absorption. The diffusional net absorption rate of anthropogenic carbon to the biosphere is some unknown function of the atmospheric partial pressure of carbon dioxide. Estimations reveal that the average carbon absorption of the forests was around 1,240 grams (1.240 Kg) of carbon per square meter of canopy area. To stabilize atmospheric CO 2 , role of forestry depends on harvesting and disturbance rates, expectations of future forest productivity, and the ability to deploy technology and forest practices to increase the retention of sequestered CO 2 . There is a considerable self-damping effect that will moderate the future increase of the atmospheric carbon dioxide concentration. Capacity of the ocean to absorb carbon dioxide is limited; but atmospheric carbon absorption potentiality of India forests can be increased tremendously through reforestation, afforestation and development of degraded forest areas and waste lands. About 60 % of Indian waste lands can be developed to increase forest cover with reasonable efforts. When

GIS based approach for atmospheric carbon absorption strategies through forests development in Indian situations

Energy Technology Data Exchange (ETDEWEB)

Yadav, Surendra Kumar [CCS Univ., Meerut (India). SCRIET

2013-07-01

Geographical information system (GIS) play important role in forest management. An effective strategy for enhancement of atmospheric carbon absorption productivity is through forests development in degraded forest areas and waste lands. Forestry sector has significant emissions removal capability which can further be enhanced by operationalizing major afforestation and reforestation initiatives like National Mission for a Green India besides continued strengthening of the present protection regime of forests. Secondary data was collected and analyzed. Different types of waste lands require different strategies for their development into forest areas; but few waste lands like rocky regions, glacier regions etc. cannot be developed into forest areas. Atmospheric carbon management is major problem before world community in present circumstances to control environmental pollution. Various forest ecosystems play significant role in carbon absorption. The diffusional net absorption rate of anthropogenic carbon to the biosphere is some unknown function of the atmospheric partial pressure of carbon dioxide. Estimations reveal that the average carbon absorption of the forests was around 1,240 grams (1.240 Kg) of carbon per square meter of canopy area. To stabilize atmospheric CO{sub 2}, role of forestry depends on harvesting and disturbance rates, expectations of future forest productivity, and the ability to deploy technology and forest practices to increase the retention of sequestered CO{sub 2}. There is a considerable self-damping effect that will moderate the future increase of the atmospheric carbon dioxide concentration. Capacity of the ocean to absorb carbon dioxide is limited; but atmospheric carbon absorption potentiality of India forests can be increased tremendously through reforestation, afforestation and development of degraded forest areas and waste lands. About 60 % of Indian waste lands can be developed to increase forest cover with reasonable efforts. When

Taxing Strategies for Carbon Emissions: A Bilevel Optimization Approach

Directory of Open Access Journals (Sweden)

Wei Wei

2014-04-01

Full Text Available This paper presents a quantitative and computational method to determine the optimal tax rate among generating units. To strike a balance between the reduction of carbon emission and the profit of energy sectors, the proposed bilevel optimization model can be regarded as a Stackelberg game between the government agency and the generation companies. The upper-level, which represents the government agency, aims to limit total carbon emissions within a certain level by setting optimal tax rates among generators according to their emission performances. The lower-level, which represents decision behaviors of the grid operator, tries to minimize the total production cost under the tax rates set by the government. The bilevel optimization model is finally reformulated into a mixed integer linear program (MILP which can be solved by off-the-shelf MILP solvers. Case studies on a 10-unit system as well as a provincial power grid in China demonstrate the validity of the proposed method and its capability in practical applications.

Carbon print: in 20 years, French gained weight. Carbon Newsletter Nr 2

International Nuclear Information System (INIS)

Grandjean, Alain; Jancovici, Jean-Marc; Paillat, Emmanuelle; Adam, Julien; Wilmotte, Jean-Yves

2011-09-01

This publication proposes another approach (ECO_2 Climat) than a simple rate between direct emissions and population to assess the average carbon emission by a French person: to calculate, not direct emissions made by the country, but emissions necessary to the fabrication of all what is consumed by French people in France, whether this fabrication is made in France or anywhere else. As, with respect to the preceding method, the assessment seems quite good (direct emissions are almost steady whereas population increases, and the individual carbon print therefore decreases), the obtained result is not so flattering. This approach is thus described, and some aspects are highlighted: average individual greenhouse gas emissions, most impacting items (food, and then manufactured products, and individual mobility), evolution of the indicator during the last 20 years, comparison with the national inventory of greenhouse gas emissions. The main variations of emissions between 1990 and 2010 are discussed: energy in housing, food, manufactured products, individual mobility, and services. A brief discussion is proposed in terms of social-professional category. Some ways to face the challenge for a transition towards a low carbon economy are highlighted

A co-confined carbonization approach to aligned nitrogen-doped mesoporous carbon nanofibers and its application as an adsorbent

International Nuclear Information System (INIS)

Chen, Aibing; Liu, Chao; Yu, Yifeng; Hu, Yongqi; Lv, Haijun; Zhang, Yue; Shen, Shufeng; Zhang, Jian

2014-01-01

Highlights: • MCNFs were synthesized by a co-confined carbonization method. • The diameter size of MCNFs with bimodal mesoporous structure can be modulated. • The obtained MCNFs manifest better adsorption capacity for SO 2 , CO 2 and Cd 2+ . - Abstract: Nitrogen-doped carbon nanofibers (MCNFs) with an aligned mesoporous structure were synthesized by a co-confined carbonization method using anodic aluminum oxide (AAO) membrane and tetraethylorthosilicate (TEOS) as co-confined templates and ionic liquids as the precursor. The as-synthesized MCNFs with the diameter of 80–120 nm possessed a bulk nitrogen content of 5.3 wt% and bimodal mesoporous structure. The nitrogen atoms were mostly bound to the graphitic network in two forms, i.e. pyridinic and pyrrolic nitrogen, providing adsorption sites for acidic gases like SO 2 and CO 2 . Cyclic experiments revealed a considerable stability of MCNFs over 20 runs of SO 2 adsorption and 15 runs for CO 2 adsorption. The MCNFs also have a preferable adsorption performance for Cd 2+

Imaging carbon nanoparticles and related cytotoxicity

International Nuclear Information System (INIS)

Cheng, C; Porter, A E; Welland, M; Muller, K; Skepper, J N; Koziol, K; Midgley, P

2009-01-01

Carbon-based nanoparticles have attracted significant attention due to their unique physical, chemical, and electrical properties. Numerous studies have been published on carbon nanoparticle toxicity; however, the results remain contradictory. An ideal approach is to combine a cell viability assay with nanometer scale imaging to elucidate the detailed physiological and structural effects of cellular exposure to nanoparticles. We have developed and applied a combination of advanced microscopy techniques to image carbon nanoparticles within cells. Specifically, we have used EFTEM, HAADF-STEM, and tomography and confocal microscopy to generate 3-D images enabling determination of nanoparticle spatial distribution in a cell. With these techniques, we can differentiate between the carbon nanoparticles and the cell in both stained and unstained sections. We found carbon nanoparticles (C 60 , single-walled carbon nanotubes (SWNT), and multi-walled carbon nanotubes (MWNT)) within the cytoplasm, lysosomes, and nucleus of human monocyte-derived macrophage cells (HMM). C 60 aggregated along the plasma and nuclear membrane while MWNTs and SWNTs were seen penetrating the plasma and nuclear membranes. Both the Neutral Red (NR) assay and ultra-structural analysis showed an increase in cell death after exposure to MWNTs and SWNTs. SWNTs were more toxic than MWNTs. For both MWNTs and SWNTs, we correlated uptake of the nanoparticles with a significant increase in necrosis. In conclusion, high resolution imaging studies provide us with significant insight into the localised interactions between carbon nanoparticles and cells. Viability assays alone only provide a broad toxicological picture of nanoparticle effects on cells whereas the high resolution images associate the spatial distributions of the nanoparticles within the cell with increased incidence of necrosis. This combined approach will enable us to probe the mechanisms of particle uptake and subsequent chemical changes within

Carbon footprinting of electronic products

International Nuclear Information System (INIS)

Vasan, Arvind; Sood, Bhanu; Pecht, Michael

2014-01-01

Highlights: • Challenges in adopting existing CF standards for electronic products are discussed. • Carbon footprint of electronic products is underestimated using existing standards. • Multipronged approach is presented to overcome the identified challenges. • Multipronged approach demonstrated on commercial and military grade DC–DC converter system. - Abstract: In order to mitigate the effects of global warming, companies are being compelled by governments, investors, and customers to control their greenhouse gas (GHG) emissions. Similar to the European Union’s legislation on the airline industry, legislation is expected to require the electronics industry to assess their product’s carbon footprint before sale or use, as the electronics industry’s contribution to global GHG emissions is comparable to the airline industry’s contribution. Thus, it is necessary for members of the electronics industry to assess their current GHG emission rates and identify methods to reduce environmental impacts. Organizations use Carbon Footprint (CF) analysis methods to identify and quantify the GHG emissions associated with the life cycle stages of their product or services. This paper discusses the prevailing methods used by organizations to estimate the CF of their electronics products and identifies the challenges faced by the electronics industry when adopting these methods in an environment of decreasing product development cycles with complex and diffuse supply chains. We find that, as a result of the inconsistencies arising from the system boundary selection methods and databases, the use of outdated LCA approaches, and the lack of supplier’s emissions-related data, the CFs of electronic products are typically underestimated. To address these challenges, we present a comprehensive approach to the carbon footprinting of electronic products that involves the use of product-group-oriented standards, hybrid life cycle assessment techniques, and the

Northern peatland carbon stocks and dynamics: a review

Directory of Open Access Journals (Sweden)

Z. C. Yu

2012-10-01

Full Text Available Peatlands contain a large belowground carbon (C stock in the biosphere, and their dynamics have important implications for the global carbon cycle. However, there are still large uncertainties in C stock estimates and poor understanding of C dynamics across timescales. Here I review different approaches and associated uncertainties of C stock estimates in the literature, and on the basis of the literature review my best estimate of C stocks and uncertainty is 500 ± 100 (approximate range gigatons of C (Gt C in northern peatlands. The greatest source of uncertainty for all the approaches is the lack or insufficient representation of data, including depth, bulk density and carbon accumulation data, especially from the world's large peatlands. Several ways to improve estimates of peat carbon stocks are also discussed in this paper, including the estimates of C stocks by regions and further utilizations of widely available basal peat ages.

Changes in peatland carbon stocks over time, estimated using Sphagnum (peat moss spore data and down-core peat accumulation records, show different patterns during the Holocene, and I argue that spore-based approach underestimates the abundance of peatlands in their early histories. Considering long-term peat decomposition using peat accumulation data allows estimates of net carbon sequestration rates by peatlands, or net (ecosystem carbon balance (NECB, which indicates more than half of peat carbon (> 270 Gt C was sequestrated before 7000 yr ago during the Holocene. Contemporary carbon flux studies at 5 peatland sites show much larger NECB during the last decade (32 ± 7.8 (S.E. g C m⁻² yr^–1 than during the last 7000 yr (∼ 11 g C m⁻² yr^–1, as modeled from peat records across northern peatlands. This discrepancy highlights the urgent need for carbon accumulation data and process understanding, especially at decadal and centennial timescales

Removal of Intermediate Aromatic Halogenated DBPs by Activated Carbon Adsorption: A New Approach to Controlling Halogenated DBPs in Chlorinated Drinking Water.

Science.gov (United States)

Jiang, Jingyi; Zhang, Xiangru; Zhu, Xiaohu; Li, Yu

2017-03-21

During chlorine disinfection of drinking water, chlorine may react with natural organic matter (NOM) and bromide ion in raw water to generate halogenated disinfection byproducts (DBPs). To mitigate adverse effects from DBP exposure, granular activated carbon (GAC) adsorption has been considered as one of the best available technologies for removing NOM (DBP precursor) in drinking water treatment. Recently, we have found that many aromatic halogenated DBPs form in chlorination, and they act as intermediate DBPs to decompose and form commonly known DBPs including trihalomethanes and haloacetic acids. In this work, we proposed a new approach to controlling drinking water halogenated DBPs by GAC adsorption of intermediate aromatic halogenated DBPs during chlorination, rather than by GAC adsorption of NOM prior to chlorination (i.e., traditional approach). Rapid small-scale column tests were used to simulate GAC adsorption in the new and traditional approaches. Significant reductions of aromatic halogenated DBPs were observed in the effluents with the new approach; the removals of total organic halogen, trihalomethanes, and haloacetic acids by the new approach always exceeded those by the traditional approach; and the effluents with the new approach were considerably less developmentally toxic than those with the traditional approach. Our findings indicate that the new approach is substantially more effective in controlling halogenated DBPs than the traditional approach.

Microwave pyrolysis using self-generated pyrolysis gas as activating agent: An innovative single-step approach to convert waste palm shell into activated carbon

Science.gov (United States)

Yek, Peter Nai Yuh; Keey Liew, Rock; Shahril Osman, Mohammad; Chung Wong, Chee; Lam, Su Shiung

2017-11-01

Waste palm shell (WPS) is a biomass residue largely available from palm oil industries. An innovative microwave pyrolysis method was developed to produce biochar from WPS while the pyrolysis gas generated as another product is simultaneously used as activating agent to transform the biochar into waste palm shell activated carbon (WPSAC), thus allowing carbonization and activation to be performed simultaneously in a single-step approach. The pyrolysis method was investigated over a range of process temperature and feedstock amount with emphasis on the yield and composition of the WPSAC obtained. The WPSAC was tested as dye adsorbent in removing methylene blue. This pyrolysis approach provided a fast heating rate (37.5°/min) and short process time (20 min) in transforming WPS into WPSAC, recording a product yield of 40 wt%. The WPSAC was detected with high BET surface area (≥ 1200 m2/g), low ash content (< 5 wt%), and high pore volume (≥ 0.54 cm3/g), thus recording high adsorption efficiency of 440 mg of dye/g. The desirable process features (fast heating rate, short process time) and the recovery of WPSAC suggest the exceptional promise of the single-step microwave pyrolysis approach to produce high-grade WPSAC from WPS.

Porous carbon spheres via microwave-assisted synthesis for capacitive deionization

International Nuclear Information System (INIS)

Liu, Yong; Pan, Likun; Chen, Taiqiang; Xu, Xingtao; Lu, Ting; Sun, Zhuo; Chua, Daniel H.C.

2015-01-01

Highlights: • Porous carbon spheres were fabricated through a fast microwave-assisted approach. • The capacitive deionization performance of Porous carbon spheres was studied. • Porous carbon spheres exhibit a high NaCl removal with good regeneration ability. - Abstract: Porous carbon spheres (PCSs) were fabricated through a fast microwave-assisted approach using sucrose as the precursor in a microwave system and subsequent thermal treatment at 600, 800 and 1000 °C. The morphology, structure and electrochemical performance of the PCSs were characterized by scanning electron microscopy, Raman spectroscopy, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy. Their electrosorption performance in NaCl solution was studied and compared with activated carbon, carbon nanotubes, reduced graphene and carbon aerogels. The results show that due to their high specific surface area and low charge transfer resistance, PCSs treated at 1000 °C exhibit high electrosorption capacity of 5.81 m g g −1 when the initial solution concentration is 500 mg l −1 , which is higher than those of other carbon materials

Fluid injection for salt water disposal and enhanced oil recovery as a potential problem for the WIPP: Proceedings of a June 1995 workshop and analysis

International Nuclear Information System (INIS)

Silva, M.K.

1996-08-01

The Waste Isolation Pilot Plant (WIPP) is a facility of the U.S. Department of Energy (DOE), designed and constructed for the permanent disposal of transuranic (TRU) defense waste. The repository is sited in the New Mexico portion of the Delaware Basin, at a depth of 655 meters, in the salt beds of the Salado Formation. The WIPP is surrounded by reserves and production of potash, crude oil and natural gas. In selecting a repository site, concerns about extensive oil field development eliminated the Mescalero Plains site in Chaves County and concerns about future waterflooding in nearby oil fields helped eliminate the Alternate II site in Lea County. Ultimately, the Los Medanos site in Eddy County was selected, relying in part on the conclusion that there were no oil reserves at the site. For oil field operations, the problem of water migrating from the injection zone, through other formations such as the Salado, and onto adjacent property has long been recognized. In 1980, the DOE intended to prohibit secondary recovery by waterflooding in one mile buffer surrounding the WIPP Site. However, the DOE relinquished the right to restrict waterflooding based on a natural resources report which maintained that there was a minimal amount of crude oil likely to exist at the WIPP site, hence waterflooding adjacent to the WIPP would be unlikely. This document presents the workshop presentations and analyses for the fluid injection for salt water disposal and enhanced oil recovery utilizing fluid injection and their potential effects on the WIPP facility

Seeded Growth Route to Noble Calcium Carbonate Nanocrystal.

Directory of Open Access Journals (Sweden)

Aminul Islam

Full Text Available A solution-phase route has been considered as the most promising route to synthesize noble nanostructures. A majority of their synthesis approaches of calcium carbonate (CaCO3 are based on either using fungi or the CO2 bubbling methods. Here, we approached the preparation of nano-precipitated calcium carbonate single crystal from salmacis sphaeroides in the presence of zwitterionic or cationic biosurfactants without external source of CO2. The calcium carbonate crystals were rhombohedron structure and regularly shaped with side dimension ranging from 33-41 nm. The high degree of morphological control of CaCO3 nanocrystals suggested that surfactants are capable of strongly interacting with the CaCO3 surface and control the nucleation and growth direction of calcium carbonate nanocrystals. Finally, the mechanism of formation of nanocrystals in light of proposed routes was also discussed.

In situ permeability modification using gelled polymer systems. Topical report, June 10, 1996--April 10, 1997

Energy Technology Data Exchange (ETDEWEB)

Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.

1997-10-01

Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program is focused on five areas: gel treatment in fractured systems; gel treatment in carbonate rocks; in-depth placement of gels; gel systems for application in carbon dioxide flooding; and gel treatment in production wells. The research program is primarily an experimental program directed at improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the first 10 months of a 28 month program is described in the following sections.

In situ permeability modification using gelled polymer systems. Annual report, April 11, 1997--April 10, 1998

Energy Technology Data Exchange (ETDEWEB)

Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.; Michnick, M.J.

1998-09-01

Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program focused on five areas: Gel treatment in fractured systems; Gel treatment in carbonate rocks; In-depth placement of gels; Gel systems for application in carbon dioxide flooding; and Gel treatment in production wells. The research program is primarily an experimental program directed toward improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the second 12 month period of a 28 month program is described.

Development of Sulfur and Carbon Tolerant Reforming Alloy Catalysts Aided by Fundamental Atomistics Insights

Energy Technology Data Exchange (ETDEWEB)

Suljo Linic

2006-08-31

Current hydrocarbon reforming catalysts suffer from rapid carbon and sulfur poisoning. Even though there is a tremendous incentive to develop more efficient catalysts, these materials are currently formulated using inefficient trial and error experimental approaches. We have utilized a novel hybrid experimental/theoretical approach, combining quantum Density Functional Theory (DFT) calculations and various state-of-the-art experimental tools, to formulate carbon tolerant reforming catalysts. We have employed DFT calculations to develop molecular insights into the elementary chemical transformations that lead to carbon poisoning of Ni catalysts. Based on the obtained molecular insights, we have identified, using DFT quantum calculation, Sn/Ni alloy as a potential carbon tolerant reforming catalyst. Sn/Ni alloy was synthesized and tested in steam reforming of methane, propane, and isooctane. We demonstrated that the alloy catalyst is carbon-tolerant under nearly stoichiometric steam-to-carbon ratios. Under these conditions, monometallic Ni is rapidly poisoned by sp2 carbon deposits. The research approach is distinguished by a few characteristics: (a) Knowledge-based, bottom-up approach, compared to the traditional trial and error approach, allows for a more efficient and systematic discovery of improved catalysts. (b) The focus is on exploring alloy materials which have been largely unexplored as potential reforming catalysts.

Ammonia modification of activated carbon to enhance carbon dioxide adsorption: Effect of pre-oxidation

Science.gov (United States)

Shafeeyan, Mohammad Saleh; Daud, Wan Mohd Ashri Wan; Houshmand, Amirhossein; Arami-Niya, Arash

2011-02-01

A commercial granular activated carbon (GAC) was subjected to thermal treatment with ammonia for obtaining an efficient carbon dioxide (CO2) adsorbent. In general, CO2 adsorption capacity of activated carbon can be increased by introduction of basic nitrogen functionalities onto the carbon surface. In this work, the effect of oxygen surface groups before introduction of basic nitrogen functionalities to the carbon surface on CO2 adsorption capacity was investigated. For this purpose two different approaches of ammonia treatment without preliminary oxidation and amination of oxidized samples were studied. Modified carbons were characterized by elemental analysis and Fourier Transform Infrared spectroscopy (FT-IR) to study the impact of changes in surface chemistry and formation of specific surface groups on adsorption properties. The texture of the samples was characterized by conducting N2 adsorption/desorption at -196 °C. CO2 capture performance of the samples was investigated using a thermogravimetric analysis (TGA). It was found that in both modification techniques, the presence of nitrogen functionalities on carbon surface generally increased the CO2 adsorption capacity. The results indicated that oxidation followed by high temperature ammonia treatment (800 °C) considerably enhanced the CO2 uptake at higher temperatures.

SU-F-T-124: Radiation Biological Equivalent Presentations OfLEM-1 and MKM Approaches in the Carbon-Ion Radiotherapy

International Nuclear Information System (INIS)

Hsi, W; Jiang, G; Sheng, Y

2016-01-01

Purpose: To study the correlations of the radiation biological equivalent doses (BED) along depth and lateral distance between LEM-1 and MKM approaches. Methods: In NIRS-MKM (Microdosimetric Kinetic Model) approach, the prescribed BED, referred as C-Eq, doses aims to present the relative biological effectiveness (RBE) for different energies of carbon-ions on a fixed 10% survival value of HCG cell with respect to convention X-ray. Instead of a fixed 10% survival, the BED doses of LEM-1 (Local Effect Model) approach, referred as X-Eq, aims to present the RBE over the whole survival curve of chordoma-like cell with alpha/beta ratio of 2.0. The relationship of physical doses as a function of C-Eq and X-Eq doses were investigated along depth and lateral distance for various sizes of cubic targets in water irradiated by carbon-ions. Results: At the center of each cubic target, the trends between physical and C-Eq or X-Eq doses can be described by a linear and 2nd order polynomial functions, respectively. Using fit functions can then calculate a scaling factor between C-Eq and X-Eq doses to have similar physical doses. With equalized C-Eq and X-Eq doses at the depth of target center, over- and under-estimated X-Eq to C-Eq are seen for depths before and after the target center, respectively. Near the distal edge along depth, sharp rising of RBE value is observed for X-Eq, but sharp dropping of RBE value is observed for C-Eq. For lateral locations near and just outside 50% dose level, sharp raising of RBE value is also seen for X-Eq, while only minor increasing with fast dropping for C-Eq. Conclusion: An analytical function to model the differences between the CEq and X-Eq doses along depth and lateral distance need to further investigated to explain varied clinic outcome of specific cancers using two different approaches to calculated BED doses.

Dissolution of carbon dioxide in aqueous electrolyte solutions, in the context of geological storage: A thermodynamic approach

International Nuclear Information System (INIS)

Liborio, Barbara

2017-01-01

This thesis studies the enthalpy of solution of carbon dioxide in electrolyte aqueous solutions. To develop theoretical models describing the systems (CO 2 -water-salt) under the geological storage conditions of carbon dioxide, it is necessary to have experimental data, namely solubility and enthalpy. In this study, a customized flow mixing unit was adapted to a SETARAM C-80 calorimeter to measure the enthalpy of CO 2 solution in aqueous electrolyte solutions (NaCl, CaCl 2 and Na 2 SO 4 ) at the ionic strengths between 2 and 6 and at temperatures between 323.1 K and 372.9 K and pressures ranging from 2 to 16 MPa. Data from the literature were used to adjust the thermodynamic phase equilibrium model in the Y-φ approach. The thermodynamic model reproduces the experimental enthalpies to plus or minus 10%. The calculation of the enthalpy in the rigorous model is strongly dependent on the data of the literature. An experimental device has been set up for the determination of the molar volume of CO 2 at infinite dilution, which is necessary for thermodynamic modeling. The carbon dioxide to be stored may contain impurities such as annexes (O 2 , N 2 , SO x , H 2 S, N y O x , H 2 , CO and Ar). Under the objective of studying the influence of these impurities, an experimental apparatus has been set up for the measurement of enthalpies of solution of SO 2 in water and aqueous solutions of NaCl and the first results are promising. (author)

Major role of marine vegetation on the oceanic carbon cycle

NARCIS (Netherlands)

Duarte, C.M.; Middelburg, J.J.; Caraco, N.

2005-01-01

The carbon burial in vegetated sediments, ignored in past assessments of carbon burial in the ocean, was evaluated using a bottom-up approach derived from upscaling a compilation of published individual estimates of carbon burial in vegetated habitats (seagrass meadows, salt marshes and mangrove

Durable superhydrophobic carbon soot coatings for sensor applications

Science.gov (United States)

Esmeryan, K. D.; Radeva, E. I.; Avramov, I. D.

2016-01-01

A novel approach for the fabrication of durable superhydrophobic (SH) carbon soot coatings used in quartz crystal microbalance (QCM) based gas or liquid sensors is reported. The method uses modification of the carbon soot through polymerization of hexamethyldisiloxane (HMDSO) by means of glow discharge RF plasma. The surface characterization shows a fractal-like network of carbon nanoparticles with diameter of ~50 nm. These particles form islands and cavities in the nanometer range, between which the plasma polymerized hexamethyldisiloxane (PPHMDSO) embeds and binds to the carbon chains and QCM surface. Such modified surface structure retains the hydrophobic nature of the soot and enhances its robustness upon water droplet interactions. Moreover, it significantly reduces the insertion loss and dynamic resistance of the QCM compared to the commonly used carbon soot/epoxy resin approach. Furthermore, the PPHMDSO/carbon soot coating demonstrates durability and no aging after more than 40 probing cycles in water based liquid environments. In addition, the surface layer keeps its superhydrophobicity even upon thermal annealing up to 540 °C. These experiments reveal an opportunity for the development of soot based SH QCMs with improved electrical characteristics, as required for high-resolution gas or liquid measurements.

Quantification of the Relative Biological Effectiveness for Ion Beam Radiotherapy: Direct Experimental Comparison of Proton and Carbon Ion Beams and a Novel Approach for Treatment Planning

International Nuclear Information System (INIS)

Elsaesser, Thilo; Weyrather, Wilma K.; Friedrich, Thomas; Durante, Marco; Iancu, Gheorghe; Kraemer, Michael; Kragl, Gabriele; Brons, Stephan; Winter, Marcus; Weber, Klaus-Josef; Scholz, Michael

2010-01-01

Purpose: To present the first direct experimental in vitro comparison of the biological effectiveness of range-equivalent protons and carbon ion beams for Chinese hamster ovary cells exposed in a three-dimensional phantom using a pencil beam scanning technique and to compare the experimental data with a novel biophysical model. Methods and Materials: Cell survival was measured in the phantom after irradiation with two opposing fields, thus mimicking the typical patient treatment scenario. The novel biophysical model represents a substantial extension of the local effect model, previously used for treatment planning in carbon ion therapy for more than 400 patients, and potentially can be used to predict effectiveness of all ion species relevant for radiotherapy. A key feature of the new approach is the more sophisticated consideration of spatially correlated damage induced by ion irradiation. Results: The experimental data obtained for Chinese hamster ovary cells clearly demonstrate that higher cell killing is achieved in the target region with carbon ions as compared with protons when the effects in the entrance channel are comparable. The model predictions demonstrate agreement with these experimental data and with data obtained with helium ions under similar conditions. Good agreement is also achieved with relative biological effectiveness values reported in the literature for other cell lines for monoenergetic proton, helium, and carbon ions. Conclusion: Both the experimental data and the new modeling approach are supportive of the advantages of carbon ions as compared with protons for treatment-like field configurations. Because the model predicts the effectiveness for several ion species with similar accuracy, it represents a powerful tool for further optimization and utilization of the potential of ion beams in tumor therapy.

Modeling the Dispersibility of Single Walled Carbon Nanotubes in Organic Solvents by Quantitative Structure-Activity Relationship Approach

Science.gov (United States)

Yilmaz, Hayriye; Rasulev, Bakhtiyor; Leszczynski, Jerzy

2015-01-01

The knowledge of physico-chemical properties of carbon nanotubes, including behavior in organic solvents is very important for design, manufacturing and utilizing of their counterparts with improved properties. In the present study a quantitative structure-activity/property relationship (QSAR/QSPR) approach was applied to predict the dispersibility of single walled carbon nanotubes (SWNTs) in various organic solvents. A number of additive descriptors and quantum-chemical descriptors were calculated and utilized to build QSAR models. The best predictability is shown by a 4-variable model. The model showed statistically good results (R2training = 0.797, Q2 = 0.665, R2test = 0.807), with high internal and external correlation coefficients. Presence of the X0Av descriptor and its negative term suggest that small size solvents have better SWCNTs solubility. Mass weighted descriptor ATS6m also indicates that heavier solvents (and small in size) most probably are better solvents for SWCNTs. The presence of the Dipole Z descriptor indicates that higher polarizability of the solvent molecule increases the solubility. The developed model and contributed descriptors can help to understand the mechanism of the dispersion process and predictorganic solvents that improve the dispersibility of SWNTs. PMID:28347035

Modeling the Dispersibility of Single Walled Carbon Nanotubes in Organic Solvents by Quantitative Structure-Activity Relationship Approach

Directory of Open Access Journals (Sweden)

Hayriye Yilmaz

2015-05-01

Full Text Available The knowledge of physico-chemical properties of carbon nanotubes, including behavior in organic solvents is very important for design, manufacturing and utilizing of their counterparts with improved properties. In the present study a quantitative structure-activity/property relationship (QSAR/QSPR approach was applied to predict the dispersibility of single walled carbon nanotubes (SWNTs in various organic solvents. A number of additive descriptors and quantum-chemical descriptors were calculated and utilized to build QSAR models. The best predictability is shown by a 4-variable model. The model showed statistically good results (R2training = 0.797, Q2 = 0.665, R2test = 0.807, with high internal and external correlation coefficients. Presence of the X0Av descriptor and its negative term suggest that small size solvents have better SWCNTs solubility. Mass weighted descriptor ATS6m also indicates that heavier solvents (and small in size most probably are better solvents for SWCNTs. The presence of the Dipole Z descriptor indicates that higher polarizability of the solvent molecule increases the solubility. The developed model and contributed descriptors can help to understand the mechanism of the dispersion process and predictorganic solvents that improve the dispersibility of SWNTs.

Globalizing carbon lock-in

International Nuclear Information System (INIS)

Unruh, Gregory C.; Carrillo-Hermosilla, Javier

2006-01-01

This paper extends the arguments surrounding carbon lock-in elaborated in Unruh (Energy Policy 28 (2000) 817; 30 (2002) 317) to countries currently undergoing industrialization. It argues that, for numerous reasons, industrializing countries are unlikely to leapfrog carbon intensive energy development. On the contrary, carbon lock-in may be globalizing and could further constrain climate change mitigation options. It is then argued that many policy recommendations ignore carbon lock-in, possibly limiting their potential for successful implementation. The paper then discusses four policy approaches that appear to have advantages given lock-in conditions. It is recognized, however, that relative ease of implementation does not necessarily equate with superiority. Instead, it is merely a path dependent outcome of past development decisions. Pursuing policies on the basis of relative implementation ease may help address the issue of climate change, but could also result in sub-optimal outcomes along other dimensions of sustainable development

Carbon allowance auction design of China's emissions trading scheme: A multi-agent-based approach

International Nuclear Information System (INIS)

Tang, Ling; Wu, Jiaqian; Yu, Lean; Bao, Qin

2017-01-01

In this paper, a multi-agent-based ETS simulation model is proposed for carbon allowance auction design in China. In the proposed model, two main agents, i.e., the government (the ETS implementer) and the firms in different sectors (the ETS targets), are considered. Under the ETS policy, all agents make various decisions individually according to their own goals, and interact with each other through three main markets: the commodity market, the primary carbon auction market and the secondary carbon trading market. Different popular auction designs are introduced into the ETS formulation to offer helpful insights into China's ETS design. (1) Generally, the ETS would lead to positive effects on China's carbon mitigation and energy structure improvement, but a negative impact on economy. (2) As for auction forms, the uniform-price design is relatively moderate, while the discriminative-price design is quite aggressive in both economic damage and emissions reduction. (3) As for carbon price, the uniform-price auction might generate a slightly higher market clearing price than the discriminative-price auction, and the prices under two auction rules fluctuate about RMB 40 per metric ton. (4) As for carbon cap, the total allowances in the carbon auction market should be carefully set to well balance economic growth and mitigation effect. - Highlights: • A multi-agent-based model is proposed for China's emissions trading scheme (ETS). • Two main economic agents are included: government and firms in different sectors. • Auction-based allocation for initial carbon allowances is especially investigated. • Economic and environmental impacts of different auction designs are analyzed. • Results confirm the validity of the model and give helpful insights into ETS design.

A co-confined carbonization approach to aligned nitrogen-doped mesoporous carbon nanofibers and its application as an adsorbent

Energy Technology Data Exchange (ETDEWEB)

Chen, Aibing [College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018 (China); Liu, Chao [College of Gemmology and Material Technics, Shijiazhuang University of Economic, Huaian Road 136, Shijiazhuang 050031 (China); Yu, Yifeng; Hu, Yongqi; Lv, Haijun; Zhang, Yue; Shen, Shufeng [College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018 (China); Zhang, Jian [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2014-07-15

Highlights: • MCNFs were synthesized by a co-confined carbonization method. • The diameter size of MCNFs with bimodal mesoporous structure can be modulated. • The obtained MCNFs manifest better adsorption capacity for SO{sub 2}, CO{sub 2} and Cd{sup 2+}. - Abstract: Nitrogen-doped carbon nanofibers (MCNFs) with an aligned mesoporous structure were synthesized by a co-confined carbonization method using anodic aluminum oxide (AAO) membrane and tetraethylorthosilicate (TEOS) as co-confined templates and ionic liquids as the precursor. The as-synthesized MCNFs with the diameter of 80–120 nm possessed a bulk nitrogen content of 5.3 wt% and bimodal mesoporous structure. The nitrogen atoms were mostly bound to the graphitic network in two forms, i.e. pyridinic and pyrrolic nitrogen, providing adsorption sites for acidic gases like SO{sub 2} and CO{sub 2}. Cyclic experiments revealed a considerable stability of MCNFs over 20 runs of SO{sub 2} adsorption and 15 runs for CO{sub 2} adsorption. The MCNFs also have a preferable adsorption performance for Cd{sup 2+}.

Hierarchically structured, nitrogen-doped carbon membranes

KAUST Repository

Wang, Hong

2017-08-03

The present invention is a structure, method of making and method of use for a novel macroscopic hierarchically structured, nitrogen-doped, nano-porous carbon membrane (HNDCMs) with asymmetric and hierarchical pore architecture that can be produced on a large-scale approach. The unique HNDCM holds great promise as components in separation and advanced carbon devices because they could offer unconventional fluidic transport phenomena on the nanoscale. Overall, the invention set forth herein covers a hierarchically structured, nitrogen-doped carbon membranes and methods of making and using such a membranes.

Strategizing Carbon-Neutral Mines: A Case for Pilot Projects

Directory of Open Access Journals (Sweden)

Ian M. Power

2014-05-01

Full Text Available Ultramafic and mafic mine tailings are a valuable feedstock for carbon mineralization that should be used to offset carbon emissions generated by the mining industry. Although passive carbonation is occurring at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond and Mount Keith nickel mines, there remains untapped potential for sequestering CO2 within these mine wastes. There is the potential to accelerate carbonation to create economically viable, large-scale CO2 fixation technologies that can operate at near-surface temperature and atmospheric pressure. We review several relevant acceleration strategies including: bioleaching of magnesium silicates; increasing the supply of CO2 via heterotrophic oxidation of waste organics; and biologically induced carbonate precipitation, as well as enhancing passive carbonation through tailings management practices and use of CO2 point sources. Scenarios for pilot scale projects are proposed with the aim of moving towards carbon-neutral mines. A financial incentive is necessary to encourage the development of these strategies. We recommend the use of a dynamic real options pricing approach, instead of traditional discounted cash-flow approaches, because it reflects the inherent value in managerial flexibility to adapt and capitalize on favorable future opportunities in the highly volatile carbon market.

Carbon-carbon primary structure for SSTO vehicles

Science.gov (United States)

Croop, Harold C.; Lowndes, Holland B.

1997-01-01

A hot structures development program is nearing completion to validate use of carbon-carbon composite structure for primary load carrying members in a single-stage-to-orbit, or SSTO, vehicle. A four phase program was pursued which involved design development and fabrication of a full-scale wing torque box demonstration component. The design development included vehicle and component selection, design criteria and approach, design data development, demonstration component design and analysis, test fixture design and analysis, demonstration component test planning, and high temperature test instrumentation development. The fabrication effort encompassed fabrication of structural elements for mechanical property verification as well as fabrication of the demonstration component itself and associated test fixturing. The demonstration component features 3D woven graphite preforms, integral spars, oxidation inhibited matrix, chemical vapor deposited (CVD) SiC oxidation protection coating, and ceramic matrix composite fasteners. The demonstration component has been delivered to the United States Air Force (USAF) for testing in the Wright Laboratory Structural Test Facility, WPAFB, OH. Multiple thermal-mechanical load cycles will be applied simulating two atmospheric cruise missions and one orbital mission. This paper discusses the overall approach to validation testing of the wing box component and presents some preliminary analytical test predictions.

Bainite formation kinetics in high carbon alloyed steel

International Nuclear Information System (INIS)

Luzginova, N.V.; Zhao, L.; Sietsma, J.

2008-01-01

In recent years, many investigations have been carried out on the modeling of the bainite formation. In the present work, a physical approach proposed in the literature is implemented to model the formation of lower bainite in high carbon steels (1 wt.% C). In this model, the carbon diffusion is assumed to control the kinetics of the bainite formation. Both the nucleation and the growth rates are considered in an Avrami type analysis. The effect of alloying elements is taken into account considering only the thermodynamics of the system. The results and the physical meaning of the model parameters are discussed. It is shown that the diffusional approach gives a reasonable description of bainite formation kinetics in high carbon steel. Only two fitting parameters are used: the first accounts for carbon grain-boundary diffusion and the second is the initial nucleation-site density. The model satisfactorily accounts for the effect of transformation temperature, but does not take into account the carbide precipitation during bainite formation and the effect of alloying elements on the diffusion coefficient of carbon

An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

DEFF Research Database (Denmark)

Filgueira, Ramón; Byron, C.J.; Comeau, L.A.

2015-01-01

, is needed to provide a rigorous assessment of the role of bivalve mariculture in the CO2 cycle. On the other hand, the discussion about the inclusion of shells of cultured bivalves into the carbon trading system should be framed in the context of ecosystem goods and services. Humans culture bivalves......The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities...... with the aim of producing food, not sequestering CO2 in their shells, therefore the main ecosystem good provided by bivalve aquaculture is meat production, and shells should be considered as by-products of this human activity. This reasoning is key to split the CO2 released due to respiration between meat...

Environmental management control systems for carbon emissions

Directory of Open Access Journals (Sweden)

Nadia Di Giacomo

2017-04-01

Full Text Available Purpose – This paper aims to focus on a global consulting company and examine how it struggled to establish an effective environmental management control system for carbon emissions for its employees’ air travel. The organisation was motivated to reduce its carbon emissions both to comply with regulation and to enhance or maintain corporate reputation. Design/methodology/approach – The paper takes a case study approach, examining internal and external documents as well as conducting interviews with senior staff. Findings – The case study investigates how Beta’s management implemented a system to reduce carbon emissions. The organisation focused on air travel, but the study finds that employee travel preferences did not radically change. Rather than reduction in carbon emissions, as planned by head office, air travel carbon emissions actually increased during the period, and, as a consequence, the reported reduction targets were significantly adjusted downwards to meet the new realities. Practical implications – The study has implications for both policy and practice for organisations seeking to improve their sustainability performance. Originality/value – The study responds to calls in the literature to undertake research to identify how management practices might reduce negative sustainability impacts, as there is little evidence of what management practices and accounting tools are being adopted, particularly in relation to carbon emissions from air travel. The paper adds to the creation of new accounting, giving visibility to carbon emission management through case study analysis.

Progressing towards post-2012 carbon markets

Energy Technology Data Exchange (ETDEWEB)

Soeren Luetken, S.; Holm Olsen, K.

2011-11-15

Confronting the end of the first Kyoto Commitment period in 2012 with no agreed outcome for global cooperation on future emission reductions, there is an urgent need to look for new opportunities for public and private cooperation to drive broad-based progress in living standards and keep projected future warming below the politically agreed 2 degrees Celsius. Responding jointly to these global challenges the United Nations environmental Program (UNEP) and its UNEP Risoe Centre (URC) have in cooperation with the Global Green Growth Institute (GGGI) prepared the Perspectives 2011. The publication focuses on the role of carbon markets in contributing to low carbon development and new mechanisms for green growth, as one core area of action to address the challenges noted above. The publication explores in ten articles, how carbon markets at national, regional and global levels can be developed and up-scaled to sustain the involvement of the private sector in leveraging finance and innovative solutions to reduce greenhouse gas emissions. The titles of the ten articles are: 1) Fragmentation of international climate policy - doom or boom for carbon markets?; 2) Perspectives on the EU carbon market; 3) China carbon market; 4) The national context of U.S. state policies for a global commons problem; 5) Mind the gap - the state-of-play of Canadian greenhouse gas mitigation; 6) Role of the UN and multilateral policies in integrating an increasingly fragmented global carbon market; 7) Making CDM work for poor and rich Africa beyond 2012 - a series of dos and don'ts; 8) Voluntary market - future perspectives; 9) Sectoral approaches as a way forward for the carbon market?; 10) The Durban outcome - a post 2012 framework approach for green house gas markets. (LN)

Progressing towards post-2012 carbon markets

Energy Technology Data Exchange (ETDEWEB)

Soeren Luetken, S; Holm Olsen, K

2011-11-15

Confronting the end of the first Kyoto Commitment period in 2012 with no agreed outcome for global cooperation on future emission reductions, there is an urgent need to look for new opportunities for public and private cooperation to drive broad-based progress in living standards and keep projected future warming below the politically agreed 2 degrees Celsius. Responding jointly to these global challenges the United Nations environmental Program (UNEP) and its UNEP Risoe Centre (URC) have in cooperation with the Global Green Growth Institute (GGGI) prepared the Perspectives 2011. The publication focuses on the role of carbon markets in contributing to low carbon development and new mechanisms for green growth, as one core area of action to address the challenges noted above. The publication explores in ten articles, how carbon markets at national, regional and global levels can be developed and up-scaled to sustain the involvement of the private sector in leveraging finance and innovative solutions to reduce greenhouse gas emissions. The titles of the ten articles are: 1) Fragmentation of international climate policy - doom or boom for carbon markets?; 2) Perspectives on the EU carbon market; 3) China carbon market; 4) The national context of U.S. state policies for a global commons problem; 5) Mind the gap - the state-of-play of Canadian greenhouse gas mitigation; 6) Role of the UN and multilateral policies in integrating an increasingly fragmented global carbon market; 7) Making CDM work for poor and rich Africa beyond 2012 - a series of dos and don'ts; 8) Voluntary market - future perspectives; 9) Sectoral approaches as a way forward for the carbon market?; 10) The Durban outcome - a post 2012 framework approach for green house gas markets. (LN)

Does carbonation of steel slag particles reduce their toxicity? An in vitro approach.

Science.gov (United States)

Ibouraadaten, Saloua; van den Brule, Sybille; Lison, Dominique

2015-06-01

Mineral carbonation can stabilize industrial residues and, in the steel industry, may contribute to simultaneously valorize CO2 emissions and slag. We hypothesized that, by restricting the leaching of metals of toxicological concern such as Cr and V, carbonation can suppress the toxicity of these materials. The cytotoxic activity (WST1 assay) of slag dusts collected from a stainless and a Linz-Donawitz (LD) steel plant, before and after carbonation, was examined in J774 macrophages. The release of Cr, V, Fe, Mn and Ni was measured after incubation in artificial lung fluids mimicking the extracellular and phagolysosomal milieu to which particles are confronted after inhalation. LD slag had the higher Fe, Mn and V content, and was more cytotoxic than stainless steel slag. The cytotoxic activity of LD but not of stainless dusts was reduced after carbonation. The cytotoxic activity of the dusts toward J774 macrophages necessitated a direct contact with the cells and was reduced in the presence of inhibitors of phagocytosis (cytochalasin D) or phagolysosome acidification (bafilomycin), pointing to a key role of metallic constituents released in phagolysosomes. This in vitro study supports a limited reduction of the cytotoxic activity of LD, but not of stainless, steel dusts upon carbonation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Approach and practices of district energy planning to achieve low carbon outcomes in China

International Nuclear Information System (INIS)

Xu, Baoping; Zhou, Shaoxiang; Hao, Lin

2015-01-01

District energy planning is an important methodology to assist in realizing a lower carbon target. However, district energy planning has not yet been incorporated into the statutory planning system in China, primarily because there are no clear standards and specifications for these plans. In this paper, we propose a general framework and low carbon estimation method for district energy planning, which is based on evaluating the low carbon energy planning practices of several new districts in China. In addition, several key points of concern in the planning process are extracted and discussed: overall infrastructure planning; co-operation between city planning and other special low carbon eco-planning; investment, financing and profitable operation; planning management mechanisms; and the management of the construction of the energy system to coincide with the project schedule. We carried out a case study of a low carbon energy plan for a new district of Beijing to evaluate our framework. Finally, we conclude that to realize the low carbon target, regional energy planning covering technologies, the market and management should be standardized as soon as possible. -- Highlights: •A general framework for district energy planning is proposed. •A case study of a low carbon energy plan for a new district is carried out. •District energy planning should be standardized as soon as possible. •The most suitable spatial scale for energy planning is at the municipal level

Voltammetric pH sensing using carbon electrodes: glassy carbon behaves similarly to EPPG.

Science.gov (United States)

Lu, Min; Compton, Richard G

2014-09-21

Developing and building on recent work based on a simple sensor for pH determination using unmodified edge plane pyrolytic graphite (EPPG) electrodes, we present a voltammetric method for pH determination using a bare unmodified glassy carbon (GC) electrode. By exploiting the pH sensitive nature of quinones present on carbon edge-plane like sites within the GC, we show how GC electrodes can be used to measure pH. The electro-reduction of surface quinone groups on the glassy carbon electrode was characterised using cyclic voltammetry (CV) and optimised with square-wave voltammetry (SWV) at 298 K and 310 K. At both temperatures, a linear correlation was observed, corresponding to a 2 electron, 2 proton Nernstian response over the aqueous pH range 1.0 to 13.1. As such, unmodified glassy carbon electrodes are seen to be pH dependent, and the Nernstian response suggests its facile use for pH sensing. Given the widespread use of glassy carbon electrodes in electroanalysis, the approach offers a method for the near-simultaneous measurement and monitoring of pH during such analyses.

How to estimate forest carbon for large areas from inventory data

Science.gov (United States)

James E. Smith; Linda S. Heath; Peter B. Woodbury

2004-01-01

Carbon sequestration through forest growth provides a low-cost approach for meeting state and national goals to reduce net accumulations of atmospheric carbon dioxide. Total forest ecosystem carbon stocks include "pools" in live trees, standing dead trees, understory vegetation, down dead wood, forest floor, and soil. Determining the level of carbon stocks in...

Low Carbon Footprint Routes for Bird Watching

Directory of Open Access Journals (Sweden)

Wei-Ta Fang

2015-03-01

Full Text Available Bird watching is one of many recreational activities popular in ecotourism. Its popularity, therefore, prompts the need for studies on energy conservation. One such environmentally friendly approach toward minimizing bird watching’s ecological impact is ensuring a reduced carbon footprint by using an economic travel itinerary comprising a series of connected routes between tourist attractions that minimizes transit time. This study used a travel-route planning approach using geographic information systems to detect the shortest path, thereby solving the problems associated with time-consuming transport. Based on the results of road network analyses, optimal travel-route planning can be determined. These methods include simulated annealing (SA and genetic algorithms (GA. We applied two algorithms in our simulation research to detect which one is an appropriate algorithm for running carbon-routing algorithms at the regional scale. SA, which is superior to GA, is considered an excellent approach to search for the optimal path to reduce carbon dioxide and high gasoline fees, thereby controlling travel time by using the shortest travel routes.

A review of single-sample-based models and other approaches for radiocarbon dating of dissolved inorganic carbon in groundwater

Science.gov (United States)

Han, L. F; Plummer, Niel

2016-01-01

Numerous methods have been proposed to estimate the pre-nuclear-detonation 14C content of dissolved inorganic carbon (DIC) recharged to groundwater that has been corrected/adjusted for geochemical processes in the absence of radioactive decay (14C0) - a quantity that is essential for estimation of radiocarbon age of DIC in groundwater. The models/approaches most commonly used are grouped as follows: (1) single-sample-based models, (2) a statistical approach based on the observed (curved) relationship between 14C and δ13C data for the aquifer, and (3) the geochemical mass-balance approach that constructs adjustment models accounting for all the geochemical reactions known to occur along a groundwater flow path. This review discusses first the geochemical processes behind each of the single-sample-based models, followed by discussions of the statistical approach and the geochemical mass-balance approach. Finally, the applications, advantages and limitations of the three groups of models/approaches are discussed.The single-sample-based models constitute the prevailing use of 14C data in hydrogeology and hydrological studies. This is in part because the models are applied to an individual water sample to estimate the 14C age, therefore the measurement data are easily available. These models have been shown to provide realistic radiocarbon ages in many studies. However, they usually are limited to simple carbonate aquifers and selection of model may have significant effects on 14C0 often resulting in a wide range of estimates of 14C ages.Of the single-sample-based models, four are recommended for the estimation of 14C0 of DIC in groundwater: Pearson's model, (Ingerson and Pearson, 1964; Pearson and White, 1967), Han & Plummer's model (Han and Plummer, 2013), the IAEA model (Gonfiantini, 1972; Salem et al., 1980), and Oeschger's model (Geyh, 2000). These four models include all processes considered in single-sample-based models, and can be used in different ranges of

Abundant pre-industrial carbon detected in Canadian Arctic headwaters: implications for the permafrost carbon feedback

Science.gov (United States)

Dean, J. F.; van der Velde, Y.; Garnett, M. H.; Dinsmore, K. J.; Baxter, R.; Lessels, J. S.; Smith, P.; Street, L. E.; Subke, J.-A.; Tetzlaff, D.; Washbourne, I.; Wookey, P. A.; Billett, M. F.

2018-03-01

Mobilization of soil/sediment organic carbon into inland waters constitutes a substantial, but poorly-constrained, component of the global carbon cycle. Radiocarbon (14C) analysis has proven a valuable tool in tracing the sources and fate of mobilized carbon, but aquatic 14C studies in permafrost regions rarely detect ‘old’ carbon (assimilated from the atmosphere into plants and soil prior to AD1950). The emission of greenhouse gases derived from old carbon by aquatic systems may indicate that carbon sequestered prior to AD1950 is being destabilized, thus contributing to the ‘permafrost carbon feedback’ (PCF). Here, we measure directly the 14C content of aquatic CO2, alongside dissolved organic carbon, in headwater systems of the western Canadian Arctic—the first such concurrent measurements in the Arctic. Age distribution analysis indicates that the age of mobilized aquatic carbon increased significantly during the 2014 snow-free season as the active layer deepened. This increase in age was more pronounced in DOC, rising from 101-228 years before sampling date (a 120%-125% increase) compared to CO2, which rose from 92-151 years before sampling date (a 59%-63% increase). ‘Pre-industrial’ aged carbon (assimilated prior to ~AD1750) comprised 15%-40% of the total aquatic carbon fluxes, demonstrating the prevalence of old carbon to Arctic headwaters. Although the presence of this old carbon is not necessarily indicative of a net positive PCF, we provide an approach and baseline data which can be used for future assessment of the PCF.

Bulk and Surface Aqueous Speciation of Calcite: Implications for Low-Salinity Waterflooding of Carbonate Reservoirs

KAUST Repository

Yutkin, Maxim P.; Mishra, Himanshu; Patzek, Tadeusz; Lee, John; Radke, Clayton J.

2017-01-01

and surface equilibria draws several important inferences about the proposed LSW oil-recovery mechanisms. Diffuse double-layer expansion (DLE) is impossible for brine ionic strength greater than 0.1 molar. Because of rapid rock/brine equilibration

Carbon stock projection in North Sumatera using multi objective land allocation approach

Science.gov (United States)

Ichwani, S. N.; Wulandari, R.; Ramachandra, A.

2018-05-01

Nowadays, GHG emission is a critical issue for environmental management due to the large scale of land cover change, especially forest cover. This study provides a protection development strategy for North Sumatera as one way to manage the area. By using Multi Objective Land Allocation (MOLA), we evaluated two GHG emission scenarios, including a Business As Usual (BAU) scenario and Protection scenario. The result shows that the province will lose the carbon stock up to 24 million tons in the year of 2035 by using a BAU scenario. On the other hand, by implementing the Protection scenario, total carbon stock that is lost in the same period is about 5 millions tons solely. It proves that protection scenario is a good scenario and effective to reduce the carbon loss. Furthermore, this scenario can be an alternative for North Sumatera spatial plan.

Elemental and stable isotopic approaches for studying the organic and inorganic carbon components in natural samples

International Nuclear Information System (INIS)

Helie, J-F

2009-01-01

The carbon cycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.

Global carbon inequality

Energy Technology Data Exchange (ETDEWEB)

Hubacek, Klaus [University of Maryland, Department of Geographical Sciences, College Park, MD (United States); Masaryk University, Department of Environmental Studies, Brno (Czech Republic); Baiocchi, Giovanni [University of Maryland, Department of Geographical Sciences, College Park, MD (United States); University of Maryland, Department of Economics, College Park, MD (United States); Feng, Kuishuang [University of Maryland, Department of Geographical Sciences, College Park, MD (United States); Munoz Castillo, Raul [University of Maryland, Department of Geographical Sciences, College Park, MD (United States); Interamerican Development Bank, Washington, DC (United States); Sun, Laixiang [University of Maryland, Department of Geographical Sciences, College Park, MD (United States); SOAS, University of London, London (United Kingdom); International Institute for Applied Systems Analysis (IIASA), Laxenburg (Austria); Xue, Jinjun [Nagoya University, Graduate School of Economics, Nagoya (Japan); Hubei University of Economics, Wuhan (China)

2017-12-01

Global climate change and inequality are inescapably linked both in terms of who contributes climate change and who suffers the consequences. This fact is also partly reflected in two United Nations (UN) processes: on the one hand, the Paris Agreement of the UN Framework Convention on Climate Change under which countries agreed to hold the increase in the global average temperature to below 2 C above pre-industrial levels and, on the other hand, the UN's Sustainable Development Goals aiming to end poverty. These agreements are seen as important foundation to put the world nations on a sustainable pathway. However, how these agreements can be achieved or whether they are even mutually compatible is less clear. We explore the global carbon inequality between and within countries and the carbon implications of poverty alleviation by combining detailed consumer expenditure surveys for different income categories for a wide range of countries with an environmentally extended multi-regional input-output approach to estimate carbon footprints of different household groups, globally, and assess the carbon implications of moving the poorest people out of poverty. Given the current context, increasing income leads to increasing carbon footprints and makes global targets for mitigating greenhouse gases more difficult to achieve given the pace of technological progress and current levels of fossil fuel dependence. We conclude that the huge level of carbon inequality requires a critical discussion of undifferentiated income growth. Current carbon-intensive lifestyles and consumption patterns need to enter the climate discourse to a larger extent. (orig.)

Global carbon inequality

International Nuclear Information System (INIS)

Hubacek, Klaus; Baiocchi, Giovanni; Feng, Kuishuang; Munoz Castillo, Raul; Sun, Laixiang; Xue, Jinjun

2017-01-01

Global climate change and inequality are inescapably linked both in terms of who contributes climate change and who suffers the consequences. This fact is also partly reflected in two United Nations (UN) processes: on the one hand, the Paris Agreement of the UN Framework Convention on Climate Change under which countries agreed to hold the increase in the global average temperature to below 2 C above pre-industrial levels and, on the other hand, the UN's Sustainable Development Goals aiming to end poverty. These agreements are seen as important foundation to put the world nations on a sustainable pathway. However, how these agreements can be achieved or whether they are even mutually compatible is less clear. We explore the global carbon inequality between and within countries and the carbon implications of poverty alleviation by combining detailed consumer expenditure surveys for different income categories for a wide range of countries with an environmentally extended multi-regional input-output approach to estimate carbon footprints of different household groups, globally, and assess the carbon implications of moving the poorest people out of poverty. Given the current context, increasing income leads to increasing carbon footprints and makes global targets for mitigating greenhouse gases more difficult to achieve given the pace of technological progress and current levels of fossil fuel dependence. We conclude that the huge level of carbon inequality requires a critical discussion of undifferentiated income growth. Current carbon-intensive lifestyles and consumption patterns need to enter the climate discourse to a larger extent. (orig.)

Sensors based on carbon nanotube field-effect transistors and molecular recognition approaches

OpenAIRE

Cid Salavert, Cristina Carlota

2009-01-01

The general objective of this thesis is to develop chemical sensors whose sensing capacities are based on the principle of molecular recognition and where the transduction is carried out by single-walled carbon nanotubes (SWCNT).The sensing device used is the carbon nanotube field-effect transistor (CNTFET). The new structure of the CNTFET allows nanotubes to be integrated at the surface of the devices, thus exploiting SWCNTs' sensitivity to changes in their environment. The functionalization...

Theoretical modeling of structure and function of cathode catalyst layers in PEMFC

International Nuclear Information System (INIS)

Wang, Q.; Eikerling, M.; Song, D.; Liu, Z.

2004-01-01

'Full text:' In this work, we first investigate transport and reaction kinetics in single agglomerates of cathode catalyst layers in proton exchange fuel cells. Two types of spherical agglomerates are evaluated, which represent limiting structures that can be obtained by distinct synthetic procedures. One type consists of a mixture of carbon/catalyst particles and proton conducting perfluorosulfonated ionomer (PFSI). The other type consists of carbon/catalyst particles and water-filled pores. Performance of the former type is rationalized on the basis of the well-known Thiele-modulus. Characteristics of the latter type are studied using Nernst-Planck and Poisson equations. Aspects of current conversion, reactant and current distributions, and catalyst utilization are explored. In general, the PFSI-filled agglomerates exhibit more homogeneous distributions of reaction rates. Effectiveness factors for them are close to one. However, it was found that proton penetration depths in waterflooded agglomerates could be quite significant as well under certain conditions, resulting in unexpectedly high catalyst utilization. The effects of agglomerate radius and of boundary conditions at the agglomerate surface are studied. Moreover, using the same approach, we evaluate the performance of a flat PFSI-free catalyst layer with water-filled pore space. Compared with conventional composite catalyst layers impregnated with PFSI, the PFSI-free layer exhibits better performance and high Pt utilization for thicknesses less than 0.1 μm. The significance of these results for the optimization catalyst layers in view of operation conditions and synthesis methods is discussed. (author)

Low carbon renewable natural gas production from coalbeds and implications for carbon capture and storage.

Science.gov (United States)

Huang, Zaixing; Sednek, Christine; Urynowicz, Michael A; Guo, Hongguang; Wang, Qiurong; Fallgren, Paul; Jin, Song; Jin, Yan; Igwe, Uche; Li, Shengpin

2017-09-18

Isotopic studies have shown that many of the world's coalbed natural gas plays are secondary biogenic in origin, suggesting a potential for gas regeneration through enhanced microbial activities. The generation of biogas through biostimulation and bioaugmentation is limited to the bioavailability of coal-derived compounds and is considered carbon positive. Here we show that plant-derived carbohydrates can be used as alternative substrates for gas generation by the indigenous coal seam microorganisms. The results suggest that coalbeds can act as natural geobioreactors to produce low carbon renewable natural gas, which can be considered carbon neutral, or perhaps even carbon negative depending on the amount of carbon sequestered within the coal. In addition, coal bioavailability is no longer a limiting factor. This approach has the potential of bridging the gap between fossil fuels and renewable energy by utilizing existing coalbed natural gas infrastructure to produce low carbon renewable natural gas and reducing global warming.Coalbeds produce natural gas, which has been observed to be enhanced by in situ microbes. Here, the authors add plant-derived carbohydrates (monosaccharides) to coal seams to be converted by indigenous microbes into natural gas, thus demonstrating a potential low carbon renewable natural gas resource.

Application of zone-folding approach to the first-principles estimation of thermodynamic properties of carbon and ZrS2 -based nanotubes.

Science.gov (United States)

Bandura, Andrei V; Porsev, Vitaly V; Evarestov, Robert A

2016-03-15

A zone-folding (ZF) approach is applied for the estimation of the phonon contributions to thermodynamic properties of carbon-and ZrS2 -based nanotubes (NTs) of hexagonal morphology with different chiralities. The results obtained are compared with those from the direct calculation of the thermodynamic properties of NTs using PBE0 hybrid exchange-correlation functional. The phonon contribution to the stability of NTs proved to be negligible for the internal energy and small for the Helmholtz free energy. It is found that the ZF approach allows us an accurate estimation of phonon contributions to internal energy, but slightly overestimates the phonon contributions to entropy. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Global ocean carbon uptake: magnitude, variability and trends

Directory of Open Access Journals (Sweden)

R. Wanninkhof

2013-03-01

Full Text Available The globally integrated sea–air anthropogenic carbon dioxide (CO2 flux from 1990 to 2009 is determined from models and data-based approaches as part of the Regional Carbon Cycle Assessment and Processes (RECCAP project. Numerical methods include ocean inverse models, atmospheric inverse models, and ocean general circulation models with parameterized biogeochemistry (OBGCMs. The median value of different approaches shows good agreement in average uptake. The best estimate of anthropogenic CO2 uptake for the time period based on a compilation of approaches is −2.0 Pg C yr−1. The interannual variability in the sea–air flux is largely driven by large-scale climate re-organizations and is estimated at 0.2 Pg C yr−1 for the two decades with some systematic differences between approaches. The largest differences between approaches are seen in the decadal trends. The trends range from −0.13 (Pg C yr−1 decade−1 to −0.50 (Pg C yr−1 decade−1 for the two decades under investigation. The OBGCMs and the data-based sea–air CO2 flux estimates show appreciably smaller decadal trends than estimates based on changes in carbon inventory suggesting that methods capable of resolving shorter timescales are showing a slowing of the rate of ocean CO2 uptake. RECCAP model outputs for five decades show similar differences in trends between approaches.

Inferring Carbon Abatement Costs in Electricity Markets: A Revealed Preference Approach using the Shale Revolution

OpenAIRE

Joseph A. Cullen; Erin T. Mansur

2014-01-01

This paper examines how much carbon emissions from the electricity industry would decrease in response to a carbon price. We show how both carbon prices and cheap natural gas reduce, in a nearly identical manner, the historic cost advantage of coal-fired power plants. The shale revolution has resulted in unprecedented variation in natural gas prices that we use to estimate the short-run price elasticity of abatement. Our estimates imply that a price of $10 ($60) per ton of carbon dioxide woul...

Synthesis of Carbon Nanotube (CNT Composite Membranes

Directory of Open Access Journals (Sweden)

Dusan Losic

2010-12-01

Full Text Available Carbon nanotubes are attractive approach for designing of new membranes for advanced molecular separation because of their unique transport properties and ability to mimic biological protein channels. In this work the synthetic approach for fabrication of carbon nanotubes (CNTs composite membranes is presented. The method is based on growth of multi walled carbon nanotubes (MWCNT using chemical vapour deposition (CVD on the template of nanoporous alumina (PA membranes. The influence of experimental conditions including carbon precursor, temperature, deposition time, and PA template on CNT growth process and quality of fabricated membranes was investigated. The synthesis of CNT/PA composites with controllable nanotube dimensions such as diameters (30–150 nm, and thickness (5–100 µm, was demonstrated. The chemical composition and morphological characteristics of fabricated CNT/PA composite membranes were investigated by various characterisation techniques including scanning electron microscopy (SEM, energy-dispersive x-ray spectroscopy (EDXS, high resolution transmission electron microscopy (HRTEM and x-ray diffraction (XRD. Transport properties of prepared membranes were explored by diffusion of dye (Rose Bengal used as model of hydrophilic transport molecule.

Secondary and tertiary gas injection in fractured carbonate rock: Experimental study

Energy Technology Data Exchange (ETDEWEB)

Karimaie, H.; Torsaeter, O. [SPE, NTNU (Norway); Darvish, G.R. [SPE, STATOIL (Norway); Lindeberg, E. [SPE, SINTEF (Norway)

2008-09-15

The use of CO{sub 2} has received considerable interest as a method of EOR but a major drawback is its availability and increasing cost. Therefore, as the number of CO{sub 2} injection projects increase, an alternative must be considered to meet the economic considerations. For this reason attention has been directed to nitrogen injection which may be a good substitute for CO{sub 2}. The purpose of the experiments described in this paper was to investigate the efficiency of oil recovery by CO{sub 2} and N{sub 2} in fractured carbonate rock. The combined effects of gravity drainage and component exchange between gas in fracture and oil in matrix on oil recovery in fractured reservoirs subjected to CO{sub 2} or nitrogen gas injection are experimentally studied. Laboratory experiments have been carried out on a low permeable outcrop chalk, as an analogue to a North Sea reservoir rock. This was surrounded by a fracture, established with a novel experimental set-up. The experiments aimed to investigate the potential of oil recovery by secondary and tertiary CO{sub 2} and nitrogen gas injection at high pressure high temperature condition. The matrix block was saturated using recombined binary mixture live oil (C{sub 1}-C{sub 7}), while the fracture was filled with a sealing material to obtain a homogeneous saturation. The sealing material was then removed by increasing the temperature which in turn creates the fracture surrounding the core. Gas was injected into the fracture at pressures above the bubble point of the oil. Oil recovery as a function of time was monitored during the experiments. Results from secondary gas injection experiments indicate that CO{sub 2} injection at elevated pressure and temperature is more efficient than N{sub 2} injection. Results from tertiary gas injection experiments also show that injection of CO{sub 2} could significantly recover the oil, even after waterflooding, compared to N{sub 2} injection. (author)

A study of charge state approach to the stopping power of MeV B, N, and O ions in carbon

International Nuclear Information System (INIS)

Li, M.M.; O'Connor, D.J.; Timmers, H.; Dastoor, P.C.

1999-01-01

The charge state approach has been applied to treat the electronic stopping powers of swift O, N and B ions in carbon foil. According to the charge state model, the contributions to the electronic stopping power of energetic projectiles passing through solid targets are due to collisional interactions and from the charge exchange process. The definition of fractional effective charge from Brandt and Kitagawa has been combined into the current charge state model. Extensive applications of this approach require data of the equilibrium charge state distributions and knowledge of charge-exchange cross sections-involving electronic capture and loss processes. Both measured data and empirical calculations of the equilibrium charge state fraction are used in the study, and the electronic capture cross sections are obtained with the eikonal Brinkman-Kramers approximation (EBK). By comparing the numerical results with the latest experimental data as well as empirical values, it is shown that the present approach slightly overestimates the energy loss at the intermediate velocity region

Comparison of regression coefficient and GIS-based methodologies for regional estimates of forest soil carbon stocks

International Nuclear Information System (INIS)

Elliott Campbell, J.; Moen, Jeremie C.; Ney, Richard A.; Schnoor, Jerald L.

2008-01-01

Estimates of forest soil organic carbon (SOC) have applications in carbon science, soil quality studies, carbon sequestration technologies, and carbon trading. Forest SOC has been modeled using a regression coefficient methodology that applies mean SOC densities (mass/area) to broad forest regions. A higher resolution model is based on an approach that employs a geographic information system (GIS) with soil databases and satellite-derived landcover images. Despite this advancement, the regression approach remains the basis of current state and federal level greenhouse gas inventories. Both approaches are analyzed in detail for Wisconsin forest soils from 1983 to 2001, applying rigorous error-fixing algorithms to soil databases. Resulting SOC stock estimates are 20% larger when determined using the GIS method rather than the regression approach. Average annual rates of increase in SOC stocks are 3.6 and 1.0 million metric tons of carbon per year for the GIS and regression approaches respectively. - Large differences in estimates of soil organic carbon stocks and annual changes in stocks for Wisconsin forestlands indicate a need for validation from forthcoming forest surveys

Cascade enzymatic reactions for efficient carbon sequestration.

Science.gov (United States)

Xia, Shunxiang; Zhao, Xueyan; Frigo-Vaz, Benjamin; Zheng, Wenyun; Kim, Jungbae; Wang, Ping

2015-04-01

Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improvement in char formability of phenolic resin for development of Carbon/Carbon composites

International Nuclear Information System (INIS)

Hajhosseini, M.; Payami, A.; Ghaffarian, S. R.; Rezadoust, A. M.

2008-01-01

In the processing of carbon/carbon composites using polymer resin as the matrix precursor, it is inevitable that a porous structure was formed after carbonization. As a result, densification by liquid phase impregnation followed by recarbonization is required to obtain a densified composite. Consequently, the char formability of resin is an important factor in reducing the number of densification cycles and hence the processing cost. In this study, a novel approach is adopted to improve the densification of carbon/carbon composites by using a new phenolic resin modified by pitch. For this purpose, soluble part of pitch was extracted and dispersed in resol type phenolic resin. The polymerization reaction was performed in presence of para-formaldehyde and a resol-pitch compound was obtained. The second compound was prepared by mixing novolac-furfural in 55:45 weight ratio containing 9% by weight hexamethylene tetramine. This compound was added to resol-pitch compound in 10,20,50 and 80 w %. The microstructure of carbonized resin was investigated by X-ray diffraction and char yield, and the linear and volumetric shrinkage were obtained. Results show that in 80:20 ratio of resol-pitch to novolac-furfural , the char yield would be maximized by 71% and volumetric shrinkage would be minimized at 16.4%. At the same time, XRD results indicate that the resin has a strong ability to graphitize carbon/carbon composites matrix as a necessary step for its processing

A coagulation-powdered activated carbon-ultrafiltration - Multiple barrier approach for removing toxins from two Australian cyanobacterial blooms

International Nuclear Information System (INIS)

Dixon, Mike B.; Richard, Yann; Ho, Lionel; Chow, Christopher W.K.; O'Neill, Brian K.; Newcombe, Gayle

2011-01-01

Cyanobacteria are a major problem for the world wide water industry as they can produce metabolites toxic to humans in addition to taste and odour compounds that make drinking water aesthetically displeasing. Removal of cyanobacterial toxins from drinking water is important to avoid serious illness in consumers. This objective can be confidently achieved through the application of the multiple barrier approach to drinking water quality and safety. In this study the use of a multiple barrier approach incorporating coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of intracellular and extracellular cyanobacterial toxins from two naturally occurring blooms in South Australia. Also investigated was the impact of these treatments on the UF flux. In this multibarrier approach, coagulation was used to remove the cells and thus the intracellular toxin while PAC was used for extracellular toxin adsorption and finally the UF was used for floc, PAC and cell removal. Cyanobacterial cells were completely removed using the UF membrane alone and when used in conjunction with coagulation. Extracellular toxins were removed to varying degrees by PAC addition. UF flux deteriorated dramatically during a trial with a very high cell concentration; however, the flux was improved by coagulation and PAC addition.

An Integrative Approach to Energy Carbon and Redox Metabolism In Cyanobacterium Synechocystis

Energy Technology Data Exchange (ETDEWEB)

Dr. Ross Overbeek

2003-06-30

The main objectives for the first year were to produce a detailed metabolic reconstruction of synechocystis sp.pcc6803 especially in interrelated arrears of photosynthesis respiration and central carbon metabolism to support a more complete understanding and modeling of this organism. Additionally, IG, Inc. provided detailed bioinformatic analysis of selected functional systems related to carbon and energy generation and utilization, and of the corresponding pathways functional roles and individual genes to support wet lab experiments by collaborators.

Toxicity and efficacy of carbon nanotubes and graphene: the utility of carbon-based nanoparticles in nanomedicine.

Science.gov (United States)

Zhang, Yongbin; Petibone, Dayton; Xu, Yang; Mahmood, Meena; Karmakar, Alokita; Casciano, Dan; Ali, Syed; Biris, Alexandru S

2014-05-01

Carbon-based nanomaterials have attracted great interest in biomedical applications such as advanced imaging, tissue regeneration, and drug or gene delivery. The toxicity of the carbon nanotubes and graphene remains a debated issue although many toxicological studies have been reported in the scientific community. In this review, we summarize the biological effects of carbon nanotubes and graphene in terms of in vitro and in vivo toxicity, genotoxicity and toxicokinetics. The dose, shape, surface chemistry, exposure route and purity play important roles in the metabolism of carbon-based nanomaterials resulting in differential toxicity. Careful examination of the physico-chemical properties of carbon-based nanomaterials is considered a basic approach to correlate the toxicological response with the unique properties of the carbon nanomaterials. The reactive oxygen species-mediated toxic mechanism of carbon nanotubes has been extensively discussed and strategies, such as surface modification, have been proposed to reduce the toxicity of these materials. Carbon-based nanomaterials used in photothermal therapy, drug delivery and tissue regeneration are also discussed in this review. The toxicokinetics, toxicity and efficacy of carbon-based nanotubes and graphene still need to be investigated further to pave a way for biomedical applications and a better understanding of their potential applications to humans.

Global agriculture and carbon trade-offs.

Science.gov (United States)

Johnson, Justin Andrew; Runge, Carlisle Ford; Senauer, Benjamin; Foley, Jonathan; Polasky, Stephen

2014-08-26

Feeding a growing and increasingly affluent world will require expanded agricultural production, which may require converting grasslands and forests into cropland. Such conversions can reduce carbon storage, habitat provision, and other ecosystem services, presenting difficult societal trade-offs. In this paper, we use spatially explicit data on agricultural productivity and carbon storage in a global analysis to find where agricultural extensification should occur to meet growing demand while minimizing carbon emissions from land use change. Selective extensification saves ∼ 6 billion metric tons of carbon compared with a business-as-usual approach, with a value of approximately $1 trillion (2012 US dollars) using recent estimates of the social cost of carbon. This type of spatially explicit geospatial analysis can be expanded to include other ecosystem services and other industries to analyze how to minimize conflicts between economic development and environmental sustainability.

Simple approach for the fabrication of screen-printed carbon-based electrode for amperometric detection on microchip electrophoresis.

Science.gov (United States)

Petroni, Jacqueline Marques; Lucca, Bruno Gabriel; Ferreira, Valdir Souza

2017-02-15

This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry. The produced amperometric sensors were coupled to polydimethylsiloxane (PDMS) microchips at end-channel configuration in order to evaluate their analytical performance. For this purpose, electrophoretic experiments were carried out using nitrite and ascorbic acid as model analytes. Separation of these substances was successfully performed within 50s with good resolution (R = 1.2) and sensitivities (713.5 pA/μM for nitrite and 255.4 pA/μM for ascorbate). The reproducibility of the fabrication method was evaluated and revealed good values concerning the peak currents obtained (8.7% for nitrite and 9.3% for ascorbate). The electrodes obtained through this method exhibited satisfactory lifetime (ca. 400 runs) over low fabrication cost (less than $1 per piece). The feasibility of the proposed device for real analysis was demonstrated through the determination of nitrite concentration levels in drinking water samples. Based on the results achieved, the approach proposed here shows itself as an interesting alternative for simple fabrication of carbon-based electrodes. Furthermore, the devices indicate great promise for other kind of analytical applications involving ME devices. Copyright © 2016 Elsevier B.V. All rights reserved.

Global assessment of soil organic carbon stocks and spatial distribution of histosols: the Machine Learning approach

Science.gov (United States)

Hengl, Tomislav

2016-04-01

Preliminary results of predicting distribution of soil organic soils (Histosols) and soil organic carbon stock (in tonnes per ha) using global compilations of soil profiles (about 150,000 points) and covariates at 250 m spatial resolution (about 150 covariates; mainly MODIS seasonal land products, SRTM DEM derivatives, climatic images, lithological and land cover and landform maps) are presented. We focus on using a data-driven approach i.e. Machine Learning techniques that often require no knowledge about the distribution of the target variable or knowledge about the possible relationships. Other advantages of using machine learning are (DOI: 10.1371/journal.pone.0125814): All rules required to produce outputs are formalized. The whole procedure is documented (the statistical model and associated computer script), enabling reproducible research. Predicted surfaces can make use of various information sources and can be optimized relative to all available quantitative point and covariate data. There is more flexibility in terms of the spatial extent, resolution and support of requested maps. Automated mapping is also more cost-effective: once the system is operational, maintenance and production of updates are an order of magnitude faster and cheaper. Consequently, prediction maps can be updated and improved at shorter and shorter time intervals. Some disadvantages of automated soil mapping based on Machine Learning are: Models are data-driven and any serious blunders or artifacts in the input data can propagate to order-of-magnitude larger errors than in the case of expert-based systems. Fitting machine learning models is at the order of magnitude computationally more demanding. Computing effort can be even tens of thousands higher than if e.g. linear geostatistics is used. Many machine learning models are fairly complex often abstract and any interpretation of such models is not trivial and require special multidimensional / multivariable plotting and data mining

A multi-tiered approach for assessing the forestry and wood products industries' impact on the carbon balance.

Science.gov (United States)

Knauf, Marcus

2015-12-01

The forestry and wood products industries play a significant role in CO 2 emissions reduction by increasing carbon stocks in living forest biomass and wood products. Moreover, wood can substitute for fossil fuels. Different methods can be used to assess the impact of regional forestry and wood products industries on regional CO 2 emissions. This article considers three of those methods and combines them into a multi-tiered approach. The multi-tiered approach proposed in this article combines: 1) a Kyoto-Protocol-oriented method focused on changes in CO 2 emissions resulting from regional industrial production, 2) a consumer-oriented method focused on changes in CO 2 emissions resulting from regional consumption, and 3) a value-creation-oriented method focused on changes in CO 2 emissions resulting from forest management and wood usage strategies. North Rhine-Westphalia is both a typical German state and an example of a region where each of these three methods yields different results. It serves as a test case with which to illustrate the advantages of the proposed approach. This case study argues that the choice of assessment methods is essential when developing and evaluating a strategy for reducing CO 2 emissions. Emissions can be reduced through various social and economic processes. Since none of the assessment methods considered above is suitable for all of these processes, only a multi-tiered approach may ensure that strategy development results in an optimal emissions reduction strategy.

Design and implementation of a caustic flooding EOR pilot at Court Bakken heavy oil reservoir

Energy Technology Data Exchange (ETDEWEB)

Xie, J.; Chung, B.; Leung, L. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Nexen Inc., Calgary, AB (Canada)

2008-10-15

Successful waterflooding has been ongoing since 1988 at the Court Bakken heavy oil field in west central Saskatchewan. There are currently 20 injectors and 28 active oil producers in the Court main unit which is owned by Nexen and Pengrowth. The Court pool has an estimated 103.8 mmbbl of original oil in place (OOIP), of which 24 per cent has been successfully recovered after 20 years of waterflooding. A high-level enhanced oil recovery (EOR) screening study was conducted to evaluate other EOR technologies for a heavy oil reservoir of this viscosity range (17 degrees API). Laboratory studies showed that caustic flooding may enhance oil recovery after waterflooding at the Court Bakken heavy oil pool. A single well test demonstrated that caustic injection effectively reduced residual oil saturation. A sector model reservoir simulation revealed that caustic flood could achieve 9 per cent incremental oil recovery in the pilot area. Following the promising laboratory results, a successful caustic flood pilot was implemented at Court heavy oil pool where the major challenges encountered were low reservoir pressure and water channeling. 6 refs., 2 tabs., 6 figs.

Carbon footprint of forest and tree utilization technologies in life cycle approach

Science.gov (United States)

Polgár, András; Pécsinger, Judit

2017-04-01

In our research project a suitable method has been developed related the technological aspect of the environmental assessment of land use changes caused by climate change. We have prepared an eco-balance (environmental inventory) to the environmental effects classification in life-cycle approach in connection with the typical agricultural / forest and tree utilization technologies. The use of balances and environmental classification makes possible to compare land-use technologies and their environmental effects per common functional unit. In order to test our environmental analysis model, we carried out surveys in sample of forest stands. We set up an eco-balance of the working systems of intermediate cutting and final harvest in the stands of beech, oak, spruce, acacia, poplar and short rotation energy plantations (willow, poplar). We set up the life-cycle plan of the surveyed working systems by using the GaBi 6.0 Professional software and carried out midpoint and endpoint impact assessment. Out of the results, we applied the values of CML 2001 - Global Warming Potential (GWP 100 years) [kg CO2-Equiv.] and Eco-Indicator 99 - Human health, Climate Change [DALY]. On the basis of the values we set up a ranking of technology. By this, we received the environmental impact classification of the technologies based on carbon footprint. The working systems had the greatest impact on global warming (GWP 100 years) throughout their whole life cycle. This is explained by the amount of carbon dioxide releasing to the atmosphere resulting from the fuel of the technologies. Abiotic depletion (ADP foss) and marine aquatic ecotoxicity (MAETP) emerged also as significant impact categories. These impact categories can be explained by the share of input of fuel and lube. On the basis of the most significant environmental impact category (carbon footprint), we perform the relative life cycle contribution and ranking of each technologies. The technological life cycle stages examined

Distributional impacts of carbon pricing: A general equilibrium approach with micro-data for households

International Nuclear Information System (INIS)

Rausch, Sebastian; Metcalf, Gilbert E.; Reilly, John M.

2011-01-01

Many policies to limit greenhouse gas emissions have at their core efforts to put a price on carbon emissions. Carbon pricing impacts households both by raising the cost of carbon intensive products and by changing factor prices. A complete analysis requires taking both effects into account. The impact of carbon pricing is determined by heterogeneity in household spending patterns across income groups as well as heterogeneity in factor income patterns across income groups. It is also affected by precise formulation of the policy (how is the revenue from carbon pricing distributed) as well as the treatment of other government policies (e.g. the treatment of transfer payments). What is often neglected in analyses of policy is the heterogeneity of impacts across households even within income or regional groups. In this paper, we incorporate 15,588 households from the U.S. Consumer and Expenditure Survey data as individual agents in a comparative-static general equilibrium framework. These households are represented within the MIT USREP model, a detailed general equilibrium model of the U.S. economy. In particular, we categorize households by full household income (factor income as well as transfer income) and apply various measures of lifetime income to distinguish households that are temporarily low-income (e.g., retired households drawing down their financial assets) from permanently low-income households. We also provide detailed within-group distributional measures of burden impacts from various policy scenarios. - Highlights: → We develop a simulation model with 15,588 households to study the distributional impacts of carbon pricing in the US. → Sources side impacts have typically been ignored in the literature biasing studies towards finding carbon pricing to be regressive. → Our general equilibrium framework allows us to capture uses and sources side impacts from carbon pricing. → We find that variation in impacts within broad socioeconomic groups may

Nonzero-Sum Relationships in Mitigating Urban Carbon Emissions: A Dynamic Network Simulation.

Science.gov (United States)

Chen, Shaoqing; Chen, Bin; Su, Meirong

2015-10-06

The "stove-pipe" way of thinking has been mostly used in mitigating carbon emissions and managing socioeconomics because of its convenience of implementation. However, systems-oriented approaches become imperative in pursuit of an efficient regulation of carbon emissions from systems as complicated as urban systems. The aim of this paper is to establish a dynamic network approach that is capable of assessing the effectiveness of carbon emissions mitigation in a more holistic way. A carbon metabolic network is constructed by modeling the carbon flows between economic sectors and environment. With the network shocked by interventions to the sectoral carbon flows, indirect emissions from the city are accounted for under certain carbon mitigation strategies. The nonzero-sum relationships between sectors and environmental components are identified based on utility analysis, which synthesize the nature of direct and indirect network interactions. The results of the case study of Beijing suggest that the stove-pipe mitigation strategies targeted the economic sectors might be not as efficient as they were expected. A direct cutting in material or energy import to the sectors may result in a rebound in indirect emissions and thus fails to achieve the carbon mitigation goal of the city as a whole. A promising way of foreseeing the dynamic mechanism of emissions is to analyze the nonzero-sum relationships between important urban components. Thinking cities as systems of interactions, the network approach is potentially a strong tool for appraising and filtering mitigation strategies of carbon emissions.

Acute toxicity of functionalized single wall carbon nanotubes: A biochemical, histopathologic and proteomics approach.

Science.gov (United States)

Ahmadi, Homa; Ramezani, Mohammad; Yazdian-Robati, Rezvan; Behnam, Behzad; Razavi Azarkhiavi, Kamal; Hashem Nia, Azadeh; Mokhtarzadeh, Ahad; Matbou Riahi, Maryam; Razavi, Bibi Marjan; Abnous, Khalil

2017-09-25

Recently carbon nanotubes (CNTs) showed promising potentials in different biomedical applications but their safe use in humans and probable toxicities are still challenging. The aim of this study was to determine the acute toxicity of functionalized single walled carbon nanotubes (SWCNTs). In this project, PEGylated and Tween functionalized SWCNTs were prepared. BALB/c mice were randomly divided into nine groups, including PEGylated SWCNTs (75,150μg/mouse) and PEG, Tween80 suspended SWCNTs, Tween 80 and a control group (intact mice). One or 7 days after intravenous injection, the mice were killed and serum and livers were collected. The oxidative stress markers, biochemical and histopathological changes were studied. Subsequently, proteomics approach was used to investigate the alterations of protein expression profiles in the liver. Results showed that there were not any significant differences in malondealdehyde (MDA), glutathione (GSH) levels and biochemical enzymes (ALT and AST) between groups, while the histopathological observations of livers showed some injuries. The results of proteomics analysis revealed indolethylamine N-Methyltransferase (INMT), glycine N-Methyltransferase (GNMT), selenium binding protein (Selenbp), thioredoxin peroxidase (TPx), TNF receptor associated protein 1(Trap1), peroxiredoxin-6 (Prdx6), electron transport flavoprotein (Etf-α), regucalcin (Rgn) and ATP5b proteins were differentially expressed in functionalized SWCNTs groups. Western blot analyses confirmed that the changes in Prdx6 were consistent with 2-DE gel analysis. In summary, acute toxicological study on two functionalized SWCNTs did not show any significant toxicity at selected doses. Proteomics analysis also showed that following exposure to functionalized SWCNTs, the expression of some proteins with antioxidant activity and detoxifying properties were increased in liver tissue. Copyright © 2017 Elsevier B.V. All rights reserved.

Implications of elevated CO2 on pelagic carbon fluxes in an Arctic mesocosm study – an elemental mass balance approach

Directory of Open Access Journals (Sweden)

J. Czerny

2013-05-01

Full Text Available Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and fluxes, in particular due to uncertainties in constraining air–sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification applying KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation, all relevant element pools and fluxes of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down the mentioned uncertainties. Water-column concentrations of particulate and dissolved organic and inorganic matter were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution as well as estimates of wall growth were developed to close the gaps in element budgets. However, losses elements from the budgets into a sum of insufficiently determined pools were detected, and are principally unavoidable in mesocosm investigation. The comparison of variability patterns of all single measured datasets revealed analytic precision to be the main issue in determination of budgets. Uncertainties in dissolved organic carbon (DOC, nitrogen (DON and particulate organic phosphorus (POP were much higher than the summed error in determination of the same elements in all other pools. With estimates provided for all other major elemental pools, mass balance calculations could be used to infer the temporal development of DOC, DON and POP pools. Future elevated pCO2 was found to enhance net autotrophic community carbon

Pyrolytic carbon membranes containing silica: morphological approach on gas transport behavior

Science.gov (United States)

Park, Ho Bum; Lee, Sun Yong; Lee, Young Moo

2005-04-01

Pyrolytic carbon membrane containing silica (C-SiO 2) is a new-class material for gas separation, and in the present work we will deal with it in view of the morphological changes arising from the difference in the molecular structure of the polymeric precursors. The silica embedded carbon membranes were fabricated by a predetermined pyrolysis step using imide-siloxane copolymers (PISs) that was synthesized from benzophenone tetracarboxylic dianhydrides (BTDA), 4,4'-oxydianiline (ODA), and amine-terminated polydimethylsiloxane (PDMS). To induce different morphologies at the same chemical composition, the copolymers were prepared using one-step (preferentially a random segmented copolymer) sand two-step polymerization (a block segmented copolymer) methods. The polymeric precursors and their pyrolytic C-SiO 2 membranes were analyzed using thermal analysis, atomic force microscopy, and transmission electron microscopy, etc. It was found that the C-SiO 2 membrane derived from the random PIS copolymer showed a micro-structure containing small well-dispersed silica domains, whereas the C-SiO 2 membrane from the block PIS copolymer exhibited a micro-structure containing large silica domains in the continuous carbon matrix. Eventually, the gas transport through these C-SiO 2 membranes was significantly affected by the morphological changes of the polymeric precursors.

Pattern recognition approach to quantify the atomic structure of graphene

DEFF Research Database (Denmark)

Kling, Jens; Vestergaard, Jacob Schack; Dahl, Anders Bjorholm

2014-01-01

We report a pattern recognition approach to detect the atomic structure in high-resolution transmission electron microscopy images of graphene. The approach provides quantitative information such as carbon-carbon bond lengths and bond length variations on a global and local scale alike. © 2014...

Carbon Cycling with Nuclear Power

Science.gov (United States)

Lackner, Klaus S.

2011-11-01

Liquid hydrocarbon fuels like gasoline, diesel or jet fuel are the most efficient ways of delivering energy to the transportation sector, in particular cars, ships and airplanes. Unfortunately, their use nearly unavoidably leads to the emission of carbon dioxide into the atmosphere. Unless an equivalent amount is removed from the air, the carbon dioxide will accumulate and significantly contribute to the man-made greenhouse effect. If fuels are made from biomass, the capture of carbon dioxide is a natural part of the cycle. Here, we discuss technical options for capturing carbon dioxide at much faster rates. We outline the basic concepts, discuss how such capture technologies could be made affordable and show how they could be integrated into a larger system approach. In the short term, the likely source of the hydrocarbon fuels is oil or gas; in the longer term, technologies that can provide energy to remove oxygen from carbon dioxide and water molecules and combine the remaining components into liquid fuels make it possible to recycle carbon between fuels and carbon dioxide in an entirely abiotic process. Here we focus on renewable and nuclear energy options for producing liquid fuels and show how air capture combined with fuel synthesis could be more economic than a transition to electric cars or hydrogen-fueled cars.

Development and application of a new biotechnology of the molasses in-situ method; detailed evaluation for selected wells in the Romashkino carbonate reservoir

Energy Technology Data Exchange (ETDEWEB)

Wagner, M.; Lungerhausen, D. [Erdoel-Erdgas Gommern GmbH (Germany); Murtada, H.; Rosenthal, G. [VEBA OEL AG, Gelsenkirchen (Germany)

1995-12-31

On the basis of different laboratory studies, by which special strains of the type Clostridium tyrobutyricum were found, the application of molasses in-situ method for the enhanced recovery of oil in Romashkino oil field was executed. In an anaerobic, 6%-molasses medium the strains produce about 11,400 mg/l of organic acids (especially butyric acid), 3,200 mg/l ethanol, butanol, etc., and more than 350 ml/g of molasses biogas with a content of 80% C0{sub 2} and 20% H{sub 2}. The metabolics of Clostridium tyrobutyricum depress the growth of SRB, whereas methanogenic bacteria grow in an undiluted fermented molasses medium very well. In this way the dominant final fermentation process is methanogenesis. By laboratory studies with original cores under the conditions of the carbonate reservoir in Bashkir, the recovery of oil increased from 15% after waterflooding to 29% OOIP during the treatment with molasses and bacteria. We developed a new biotechnological method for a self-regulated, automatic continuous culture and constructed a special pilot plant with a high technical standard. The plant produced during the pilot on Romashkino field (September 1992 to August 1994) about 1,000 m{sup 3} of clean inoculum with a content of 3-4 billion cells per ml. This inoculum was injected in slugs together with 15,000 m{sup 3} of molasses medium, first in one, later in five wells. We will demonstrate for two example wells the complex microbiological and chemical changes in the oil, gas, and water phases, and their influences on the recover of oil.

A forward-backward SDEs approach to pricing in carbon markets

CERN Document Server

Chassagneux, Jean-François; Muûls, Mirabelle

2017-01-01

In Mathematical Finance, the authors consider a mathematical model for the pricing of emissions permits. The model has particular applicability to the European Union Emissions Trading System (EU ETS) but could also be used to consider the modeling of other cap-and-trade schemes. As a response to the risk of Climate Change, carbon markets are currently being implemented in regions worldwide and already represent more than $30 billion. However, scientific, and particularly mathematical, studies of these carbon markets are needed in order to expose their advantages and shortcomings, as well as allow their most efficient implementation. This Brief reviews mathematical properties such as the existence and uniqueness of solutions for the pricing problem, stability of solutions and their behavior. These fit into the theory of fully coupled forward-backward stochastic differential equations (FBSDEs) with irregular coefficients. The authors present a numerical algorithm to compute the solution to these non-standard FB...

Measurements of Carbon Dioxide, Carbon Monoxide, and Other Related Tracers at High Spatial and Temporal Resolution in an Urban Environment

Science.gov (United States)

Rella, C.; Jacobson, G.

2012-04-01

The ability to quantify the sources and sinks of carbon dioxide on the urban scale is essential for understanding the atmospheric drivers to global climate change. In the 'top-down' approach, overall carbon fluxes are determined by combining remote measurements of carbon dioxide concentrations with complex atmospheric transport models, and these emissions measurements are compared to "bottoms-up" predictions based on detailed inventories of the sources and sinks of carbon, both anthropogenic and biogenic in nature. This approach, which has been proven to be effective at continental scales, becomes challenging to implement at the urban scale, due to poorly understood micrometeorological atmospheric transport models and high variability of the emissions sources in space (e.g., factories, highways, residences) and time (rush hours, factory shifts and shutdowns, residential energy usage variability during the day and over the year). New measurement and analysis techniques are required to make sense of the carbon dioxide signal in cities. Here we present detailed, high spatial- and temporal-resolution greenhouse gas measurements in Silicon Valley in California. The synthesis of two experimental campaigns is presented: real-time measurements from two ten-meter urban 'towers,' and ground-based mobile mapping measurements. Real-time carbon dioxide data from a nine-month period are combined with real-time carbon monoxide, methane, acetylene, and carbon 13 measurements to partition the observed CO2 concentrations between different anthropogenic sectors (e.g., transport, residential) and biogenic sources. The carbon monoxide to carbon dioxide ratio is shown to vary over more than a factor of two from season to season or even from day to night, indicating rapid and frequent shifts in the balance between different carbon dioxide sources. Clear differences are seen between the two urban sites, which are separated by 7 km. Further information is given by the carbon 13 signature

Participatory approach in planning for low carbon and eco-village: A case of Felda Taib Andak

International Nuclear Information System (INIS)

Ngah, I; Zulkifli, A S

2014-01-01

Participatory approaches have becoming an important tool in planning of sustainable communities. Although participation is conceived as a malleable concept there are certain methods that planners can adopt to ensure a meaningful participation. This paper will provide some experiences and lessons on how participatory planning could be carried out with local people, the role of planners in the process of plan preparation, implementation and the outcome. This paper first explores some of the meanings of participation, the criteria of participation and the approaches of participation in planning for sustainable community. The second part is a description and discussion of how participatory approach in planning was applied in planning for low carbon and eco-village in Iskandar Malaysia based on a case study of planning of Felda Taib Andak scheme. The participatory approach involved a series of meetings, site visit and focus group discussions with representative of the Felda Village to come out with action plan and actual implementation. From focus group discussions a roadmap consisted of a vision and objectives and a dozen actions were formulated and adopted. In the process of implementation the main implementation and coordination committee was form in which the author (planner) is one of its members to look into fund raising and implementation strategies together with the local people. Several task forces or sub committees responsible to implement the dozen actions were also formed. The outcome was encouraging in which some of the actions such as planting of bamboo trees, reduction of pollution from oil palm factory and bicycling activities has been implemented and shown progress. The paper also highlights some of the issues and challenges in participatory planning

Accounting for forest carbon pool dynamics in product carbon footprints: Challenges and opportunities

International Nuclear Information System (INIS)

Newell, Joshua P.; Vos, Robert O.

2012-01-01

Modification and loss of forests due to natural and anthropogenic disturbance contribute an estimated 20% of annual greenhouse gas (GHG) emissions worldwide. Although forest carbon pool modeling rarely suggests a ‘carbon neutral’ flux profile, the life cycle assessment community and associated product carbon footprint protocols have struggled to account for the GHG emissions associated with forestry, specifically, and land use generally. Principally, this is due to underdeveloped linkages between life cycle inventory (LCI) modeling for wood and forest carbon modeling for a full range of forest types and harvest practices, as well as a lack of transparency in globalized forest supply chains. In this paper, through a comparative study of U.S. and Chinese coated freesheet paper, we develop the initial foundations for a methodology that rescales IPCC methods from the national to the product level, with reference to the approaches in three international product carbon footprint protocols. Due to differences in geographic origin of the wood fiber, the results for two scenarios are highly divergent. This suggests that both wood LCI models and the protocols need further development to capture the range of spatial and temporal dimensions for supply chains (and the associated land use change and modification) for specific product systems. The paper concludes by outlining opportunities to measure and reduce uncertainty in accounting for net emissions of biogenic carbon from forestland, where timber is harvested for consumer products. - Highlights: ► Typical life cycle assessment practice for consumer products often excludes significant land use change emissions when estimating carbon footprints. ► The article provides a methodology to rescale IPCC guidelines for product-level carbon footprints. ► Life cycle inventories and product carbon footprint protocols need more comprehensive land use-related accounting. ► Interdisciplinary collaboration linking the LCA and

Giant electrical power factor in single-walled chiral carbon nanotube

International Nuclear Information System (INIS)

Mensah, S.Y.; Allotey, F.K.A.; Mensah, N.G.; Nkrumah, G.

2001-10-01

Using the semiclassical approach we studied the thermoelectrical properties of single-walled chiral carbon nanotubes (SWNTs). We predict a giant electrical power factor and hence proposed the use of carbon nanotubes as thermoelements for refrigeration. (author)

ASSESSMENT OF HOUSEHOLD CARBON FOOTPRINT REDUCTION POTENTIALS

Energy Technology Data Exchange (ETDEWEB)

Kramer, Klaas Jan; Homan, Greg; Brown, Rich; Worrell, Ernst; Masanet, Eric

2009-04-15

The term ?household carbon footprint? refers to the total annual carbon emissions associated with household consumption of energy, goods, and services. In this project, Lawrence Berkeley National Laboratory developed a carbon footprint modeling framework that characterizes the key underlying technologies and processes that contribute to household carbon footprints in California and the United States. The approach breaks down the carbon footprint by 35 different household fuel end uses and 32 different supply chain fuel end uses. This level of end use detail allows energy and policy analysts to better understand the underlying technologies and processes contributing to the carbon footprint of California households. The modeling framework was applied to estimate the annual home energy and supply chain carbon footprints of a prototypical California household. A preliminary assessment of parameter uncertainty associated with key model input data was also conducted. To illustrate the policy-relevance of this modeling framework, a case study was conducted that analyzed the achievable carbon footprint reductions associated with the adoption of energy efficient household and supply chain technologies.

Persistent cyclestability of carbon coated Zn–Sn metal oxide/carbon microspheres as highly reversible anode material for lithium-ion batteries

International Nuclear Information System (INIS)

Fang, Guoqing; Kaneko, Shingo; Liu, Weiwei; Xia, Bingbo; Sun, Hongdan; Zhang, Ruixue; Zheng, Junwei; Li, Decheng

2013-01-01

Development of high-capacity anode materials equipped with strong cyclestability is a great challenge for use as practical electrode for high-performance lithium-ion rechargeable battery. In this study, we synthesized a carbon coated Zn–Sn metal nanocomposite oxide and carbon spheres (ZTO@C/CSs) via a simple glucose hydrothermal reaction and subsequent carbonization approach. The carbon coated ZTO/carbon microspheres composite maintained a reversible capacity of 680 mAh g −1 after 345 cycles at a current density of 100 mA g −1 , and furthermore the cell based on the composite exhibited an excellent rate capability of 470 mAh g −1 even when the cell was cycled at 2000 mA g –1 . The thick carbon layer formed on the ZTO nanoparticles and carbon spheres effectively buffered the volumetric change of the particles, which thus prolonged the cycling performance of the electrodes

Underground coal gasification with extended CO2 utilization as economic and carbon neutral approach to address energy and fertilizer supply shortages in Bangladesh

Science.gov (United States)

Nakaten, Natalie; Islam, Rafiqul; Kempka, Thomas

2014-05-01

The application of underground coal gasification (UCG) with proven carbon mitigation techniques may provide a carbon neutral approach to tackle electricity and fertilizer supply shortages in Bangladesh. UCG facilitates the utilization of deep-seated coal seams, not economically exploitable by conventional coal mining. The high-calorific synthesis gas produced by UCG can be used for e.g. electricity generation or as chemical raw material for hydrogen, methanol and fertilizer production. Kempka et al. (2010) carried out an integrated assessment of UCG operation, demonstrating that about 19 % of the CO2 produced during UCG may be mitigated by CO2 utilization in fertilizer production. In the present study, we investigated an extension of the UCG system by introducing excess CO2 storage in the gas deposit of the Bahkrabad gas field (40 km east of Dhaka, Bangladesh). This gas field still holds natural gas resources of 12.8 million tons of LNG equivalent, but is close to abandonment due to a low reservoir pressure. Consequently, applying enhanced gas recovery (EGR) by injection of excess carbon dioxide from the coupled UCG-urea process may mitigate carbon emissions and support natural gas production from the Bahkrabad gas field. To carry out an integrated techno-economic assessment of the coupled system, we adapted the techno-economic UCG-CCS model developed by Nakaten et al. (2014) to consider the urea and EGR processes. Reservoir simulations addressing EGR in the Bakhrabad gas field by utilization of excess carbon dioxide from the UCG process were carried out to account for the induced pressure increase in the reservoir, and thus additional gas recovery potentials. The Jamalganj coal field in Northwest Bangladesh provides favorable geological and infrastructural conditions for a UCG operation at coal seam depths of 640 m to 1,158 m. Excess CO2 can be transported via existing pipeline networks to the Bahkrabad gas field (about 300 km distance from the coal deposit) to be

Ultrathin diamond-like carbon films deposited by filtered carbon vacuum arcs

International Nuclear Information System (INIS)

Anders, Andre; Fong, Walton; Kulkarni, Ashok; Ryan, Francis W.; Bhatia, C. Singh

2001-01-01

Ultrathin ( and lt; 5 nm) hard carbon films are of great interest to the magnetic storage industry as the areal density approaches 100 Gbit/in(sup 2). These films are used as overcoats to protect the magnetic layers on disk media and the active elements of the read-write slider. Tetrahedral amorphous carbon films can be produced by filtered cathodic arc deposition, but the films will only be accepted by the storage industry only if the ''macroparticle'' issue has been solved. Better plasma filters have been developed over recent years. Emphasis is put on the promising twist filter system - a compact, open structure that operates with pulsed arcs and high magnetic field. Based on corrosion tests it is shown that the macroparticle reduction by the twist filter is satisfactory for this demanding application, while plasma throughput is very high. Ultrathin hard carbon films have been synthesized using S-filter and twist filter systems. Film properties such as hardness, elastic modulus, wear, and corrosion resistance have been tested

Improved characterization of reservoir behavior by integration of reservoir performances data and rock type distributions

Energy Technology Data Exchange (ETDEWEB)

Davies, D.K.; Vessell, R.K. [David K. Davies & Associates, Kingwood, TX (United States); Doublet, L.E. [Texas A& M Univ., College Station, TX (United States)] [and others

1997-08-01

An integrated geological/petrophysical and reservoir engineering study was performed for a large, mature waterflood project (>250 wells, {approximately}80% water cut) at the North Robertson (Clear Fork) Unit, Gaines County, Texas. The primary goal of the study was to develop an integrated reservoir description for {open_quotes}targeted{close_quotes} (economic) 10-acre (4-hectare) infill drilling and future recovery operations in a low permeability, carbonate (dolomite) reservoir. Integration of the results from geological/petrophysical studies and reservoir performance analyses provide a rapid and effective method for developing a comprehensive reservoir description. This reservoir description can be used for reservoir flow simulation, performance prediction, infill targeting, waterflood management, and for optimizing well developments (patterns, completions, and stimulations). The following analyses were performed as part of this study: (1) Geological/petrophysical analyses: (core and well log data) - {open_quotes}Rock typing{close_quotes} based on qualitative and quantitative visualization of pore-scale features. Reservoir layering based on {open_quotes}rock typing {close_quotes} and hydraulic flow units. Development of a {open_quotes}core-log{close_quotes} model to estimate permeability using porosity and other properties derived from well logs. The core-log model is based on {open_quotes}rock types.{close_quotes} (2) Engineering analyses: (production and injection history, well tests) Material balance decline type curve analyses to estimate total reservoir volume, formation flow characteristics (flow capacity, skin factor, and fracture half-length), and indications of well/boundary interference. Estimated ultimate recovery analyses to yield movable oil (or injectable water) volumes, as well as indications of well and boundary interference.

Biogenic carbon in combustible waste: waste composition, variability and measurement uncertainty.

Science.gov (United States)

Larsen, Anna W; Fuglsang, Karsten; Pedersen, Niels H; Fellner, Johann; Rechberger, Helmut; Astrup, Thomas

2013-10-01

Obtaining accurate data for the contents of biogenic and fossil carbon in thermally-treated waste is essential for determination of the environmental profile of waste technologies. Relations between the variability of waste chemistry and the biogenic and fossil carbon emissions are not well described in the literature. This study addressed the variability of biogenic and fossil carbon in combustible waste received at a municipal solid waste incinerator. Two approaches were compared: (1) radiocarbon dating ((14)C analysis) of carbon dioxide sampled from the flue gas, and (2) mass and energy balance calculations using the balance method. The ability of the two approaches to accurately describe short-term day-to-day variations in carbon emissions, and to which extent these short-term variations could be explained by controlled changes in waste input composition, was evaluated. Finally, the measurement uncertainties related to the two approaches were determined. Two flue gas sampling campaigns at a full-scale waste incinerator were included: one during normal operation and one with controlled waste input. Estimation of carbon contents in the main waste types received was included. Both the (14)C method and the balance method represented promising methods able to provide good quality data for the ratio between biogenic and fossil carbon in waste. The relative uncertainty in the individual experiments was 7-10% (95% confidence interval) for the (14)C method and slightly lower for the balance method.

Determination of morphology and properties of carbon nanofibers and carbon nanofiber polymer nanocomposites

Science.gov (United States)

Lawrence, Joseph G.

individual nanofibers was found to depend on the thickness of the nanofiber. In an effort to study the morphology and properties of polymer nanocomposites, the dispersion of the nanofibers in the polymer matrix was studied using a Scanning Electron Microscope (SEM). A mixing approach and an in situ polymerization approach, for carbon nanofiber polyimide nanocomposites preparation were investigated using pristine, oxidized and surface functionalized nanofibers. Two different solvents, methylene chloride and dimethylacetimide (DMAc) were compared in the mixing approach. The SEM micrographs indicated that the poor dispersion of nanofibers results in aggregation and settling of nanofibers in the nanocomposite sample. The results suggest that the nanocomposite preparation method had a greater effect on the dispersion of nanofibers compared to the extent of nanofiber functionalization. In addition, a modified nanoindentation approach to measure the interface width and elastic properties at the interface of carbon nanofiber polymer nanocomposites was developed. Using the developed method the elastic property variation at narrow interface regions for two different composites made from three different nanofibers was studied. A gradual change in elastic modulus values was observed at the interface region. Based on the variation in elastic modulus values, the width of the interface region was determined.

Can greening of aquaculture sequester blue carbon?

Science.gov (United States)

Ahmed, Nesar; Bunting, Stuart W; Glaser, Marion; Flaherty, Mark S; Diana, James S

2017-05-01

Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.

Carbon fiber microelectrodes modified with carbon nanotubes as a new support for immobilization of glucose oxidase

International Nuclear Information System (INIS)

Wen, H.; Nallathambi, V.; Chakraborty, D.; Barton, S.C.

2011-01-01

Carboxylated carbon nanotubes were coated onto carbon microfiber electrodes to create a micron-scale bioelectrode. This material has a high surface area and can serve as a support for immobilization of enzymes such as glucose oxidase. A typical carbon nanotube loading of 13 μg cm -1 yields a coating thickness of 17 μm and a 2000-fold increase in surface capacitance. The modified electrode was further coated with a biocatalytic hydrogel composed of a conductive redox polymer, glucose oxidase, and a crosslinker to create a glucose bioelectrode. The current density on oxidation of glucose is 16.6 mA cm-2 at 0.5 V (vs. Ag/AgCl) in oxygen-free glucose solution. We consider this approach to be useful for designing and characterizing surface treatments for carbon mats and papers by mimicking their local microenvironment. (author)

Scalable Approach To Construct Free-Standing and Flexible Carbon Networks for Lithium–Sulfur Battery

KAUST Repository

Li, Mengliu

2017-02-21

Reconstructing carbon nanomaterials (e.g., fullerene, carbon nanotubes (CNTs), and graphene) to multidimensional networks with hierarchical structure is a critical step in exploring their applications. Herein, a sacrificial template method by casting strategy is developed to prepare highly flexible and free-standing carbon film consisting of CNTs, graphene, or both. The scalable size, ultralight and binder-free characteristics, as well as the tunable process/property are promising for their large-scale applications, such as utilizing as interlayers in lithium-sulfur battery. The capability of holding polysulfides (i.e., suppressing the sulfur diffusion) for the networks made from CNTs, graphene, or their mixture is pronounced, among which CNTs are the best. The diffusion process of polysulfides can be visualized in a specially designed glass tube battery. X-ray photoelectron spectroscopy analysis of discharged electrodes was performed to characterize the species in electrodes. A detailed analysis of lithium diffusion constant, electrochemical impedance, and elementary distribution of sulfur in electrodes has been performed to further illustrate the differences of different carbon interlayers for Li-S batteries. The proposed simple and enlargeable production of carbon-based networks may facilitate their applications in battery industry even as a flexible cathode directly. The versatile and reconstructive strategy is extendable to prepare other flexible films and/or membranes for wider applications.

Carbon trading and carbon taxation: how to consider biotic sources and sinks

International Nuclear Information System (INIS)

Madlener, Reinhard; Schlamadinger, Bernhard

1999-01-01

The Kyoto Protocol (KP) to the UNFCCC includes land-use change and forestry in the carbon accounting process, limited to afforestation, reforestation and deforestation since 1990, and explicitly provides for the option of using a variety of flexibility mechanisms to meet the greenhouse gas (GHG) reduction targets stipulated in a more cost-efficient manner. Domestically, different countries might adopt different approaches to achieve their emission reduction objectives, such as carbon trading or carbon taxation, and it is not clear to date what the implications for bioenergy use, forestry, and land-use change can be expected to be. With respect to national GHG emissions trading, the main issues studied in this paper are: Should trading of fossil fuel emissions allowances be coupled with trading of biotic credits and debits? Should credits for carbon sequestration in forests be auctioned or grandfathered? Should there be a distinction between a carbon permit issued for an additional biotic sink and those issued for fossil fuel carbon emissions? Is there a difference for biotic carbon sinks and sources between one-time permits and permits that allow a continued release of GHG over some pre-specified time? Should permits be issued only for the carbon-stock changes that count under the KP? With respect to national carbon taxation schemes, two questions are investigated: Should a tax credit be given for afforestation/reforestation (and a tax debit for deforestation)? Should tax credits also be given for projects that sequester carbon but do not count under the KP (such as forest protection rather than forest management)? For both schemes a crucial point is that by the formulation chosen in the KP two different classes of forest are created (i.e. those counted and those not counted under the KP), so that the implications for land prices might be significant. From a conceptual point of view this paper addresses the above-mentioned questions and contrasts some of the major

A facile approach for the synthesis of monolithic hierarchical porous carbons – high performance materials for amine based CO2 capture and supercapacitor electrode

KAUST Repository

Estevez, Luis

2013-05-03

An ice templating coupled with hard templating and physical activation approach is reported for the synthesis of hierarchically porous carbon monoliths with tunable porosities across all three length scales (macro- meso- and micro), with ultrahigh specific pore volumes [similar]11.4 cm3 g−1. The materials function well as amine impregnated supports for CO2 capture and as supercapacitor electrodes.

Biorefineries of carbon dioxide: From carbon capture and storage (CCS) to bioenergies production.

Science.gov (United States)

Cheah, Wai Yan; Ling, Tau Chuan; Juan, Joon Ching; Lee, Duu-Jong; Chang, Jo-Shu; Show, Pau Loke

2016-09-01

Greenhouse gas emissions have several adverse environmental effects, like pollution and climate change. Currently applied carbon capture and storage (CCS) methods are not cost effective and have not been proven safe for long term sequestration. Another attractive approach is CO2 valorization, whereby CO2 can be captured in the form of biomass via photosynthesis and is subsequently converted into various form of bioenergy. This article summarizes the current carbon sequestration and utilization technologies, while emphasizing the value of bioconversion of CO2. In particular, CO2 sequestration by terrestrial plants, microalgae and other microorganisms are discussed. Prospects and challenges for CO2 conversion are addressed. The aim of this review is to provide comprehensive knowledge and updated information on the current advances in biological CO2 sequestration and valorization, which are essential if this approach is to achieve environmental sustainability and economic feasibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Progress Toward Sequestering Carbon Nanotubes in PmPV

Science.gov (United States)

Bley, Richard A.

2009-01-01

Sequestration of single-walled carbon nanotubes (SWNTs) in molecules of poly(m-phenylenevinylene-co-2,5-diocty-loxy-p-phenylenevinylene) [PmPV] is a candidate means of promoting dissolution of single-walled carbon nanotubes (SWNTs) into epoxies for making strong, lightweight epoxy-matrix/carbon-fiber composite materials. Bare SWNTs cannot be incorporated because they are not soluble in epoxies. In the present approach, one exploits the tendency of PmPV molecules to wrap themselves around SWNTs without chemically bonding to them.

Using 50 years of soil radiocarbon data to identify optimal approaches for estimating soil carbon residence times

Science.gov (United States)

Baisden, W. T.; Canessa, S.

2013-01-01

In 1959, Athol Rafter began a substantial programme of systematically monitoring the flow of 14C produced by atmospheric thermonuclear tests through organic matter in New Zealand soils under stable land use. A database of ∼500 soil radiocarbon measurements spanning 50 years has now been compiled, and is used here to identify optimal approaches for soil C-cycle studies. Our results confirm the potential of 14C to determine residence times, by estimating the amount of ‘bomb 14C’ incorporated. High-resolution time series confirm this approach is appropriate, and emphasise that residence times can be calculated routinely with two or more time points as little as 10 years apart. This approach is generally robust to the key assumptions that can create large errors when single time-point 14C measurements are modelled. The three most critical assumptions relate to: (1) the distribution of turnover times, and particularly the proportion of old C (‘passive fraction’), (2) the lag time between photosynthesis and C entering the modelled pool, (3) changes in the rates of C input. When carrying out approaches using robust assumptions on time-series samples, multiple soil layers can be aggregated using a mixing equation. Where good archived samples are available, AMS measurements can develop useful understanding for calibrating models of the soil C cycle at regional to continental scales with sample numbers on the order of hundreds rather than thousands. Sample preparation laboratories and AMS facilities can play an important role in coordinating the efficient delivery of robust calculated residence times for soil carbon.

Using 50 years of soil radiocarbon data to identify optimal approaches for estimating soil carbon residence times

International Nuclear Information System (INIS)

Baisden, W.T.; Canessa, S.

2013-01-01

In 1959, Athol Rafter began a substantial programme of systematically monitoring the flow of 14 C produced by atmospheric thermonuclear tests through organic matter in New Zealand soils under stable land use. A database of ∼500 soil radiocarbon measurements spanning 50 years has now been compiled, and is used here to identify optimal approaches for soil C-cycle studies. Our results confirm the potential of 14 C to determine residence times, by estimating the amount of ‘bomb 14 C’ incorporated. High-resolution time series confirm this approach is appropriate, and emphasise that residence times can be calculated routinely with two or more time points as little as 10 years apart. This approach is generally robust to the key assumptions that can create large errors when single time-point 14 C measurements are modelled. The three most critical assumptions relate to: (1) the distribution of turnover times, and particularly the proportion of old C (‘passive fraction’), (2) the lag time between photosynthesis and C entering the modelled pool, (3) changes in the rates of C input. When carrying out approaches using robust assumptions on time-series samples, multiple soil layers can be aggregated using a mixing equation. Where good archived samples are available, AMS measurements can develop useful understanding for calibrating models of the soil C cycle at regional to continental scales with sample numbers on the order of hundreds rather than thousands. Sample preparation laboratories and AMS facilities can play an important role in coordinating the efficient delivery of robust calculated residence times for soil carbon.

Cross validation of two partitioning-based sampling approaches in mesocosms containing PCB contaminated field sediment, biota, and activated carbon amendment

DEFF Research Database (Denmark)

Nørgaard Schmidt, Stine; Wang, Alice P.; Gidley, Philip T

2017-01-01

with multiple thicknesses of silicone and in situ pre-equilibrium sampling with low density polyethylene (LDPE) loaded with performance reference compounds were applied independently to measure polychlorinated biphenyls (PCBs) in mesocosms with (1) New Bedford Harbor sediment (MA, USA), (2) sediment and biota......, and (3) activated carbon amended sediment and biota. The aim was to cross validate the two different sampling approaches. Around 100 PCB congeners were quantified in the two sampling polymers, and the results confirmed the good precision of both methods and were in overall good agreement with recently...... published silicone to LDPE partition ratios. Further, the methods yielded Cfree in good agreement for all three experiments. The average ratio between Cfree determined by the two methods was factor 1.4±0.3 (range: 0.6-2.0), and the results thus cross-validated the two sampling approaches. For future...

Living Shorelines: Coastal Resilience with a Blue Carbon Benefit.

Science.gov (United States)

Davis, Jenny L; Currin, Carolyn A; O'Brien, Colleen; Raffenburg, Craig; Davis, Amanda

2015-01-01

Living shorelines are a type of estuarine shoreline erosion control that incorporates native vegetation and preserves native habitats. Because they provide the ecosystem services associated with natural coastal wetlands while also increasing shoreline resilience, living shorelines are part of the natural and hybrid infrastructure approach to coastal resiliency. Marshes created as living shorelines are typically narrow (erosion control and habitat for estuarine organisms has been documented but their capacity for carbon sequestration has not. We measured carbon sequestration rates in living shorelines and sandy transplanted Spartina alterniflora marshes in the Newport River Estuary, North Carolina. The marshes sampled here range in age from 12 to 38 years and represent a continuum of soil development. Carbon sequestration rates ranged from 58 to 283 g C m-2 yr-1 and decreased with marsh age. The pattern of lower sequestration rates in older marshes is hypothesized to be the result of a relative enrichment of labile organic matter in younger sites and illustrates the importance of choosing mature marshes for determination of long-term carbon sequestration potential. The data presented here are within the range of published carbon sequestration rates for S. alterniflora marshes and suggest that wide-scale use of the living shoreline approach to shoreline management may come with a substantial carbon benefit.

Energy and carbon embodied in the international trade of Brazil. An input-output approach

International Nuclear Information System (INIS)

Machado, G; Schaeffer, R.; Worrell, E.

2001-01-01

All goods and services produced in an economy are directly and/or indirectly associated with energy use and, according to the type of fuel utilized, with CO2 emissions as well. International trade is an important factor in shaping the industrial structure of a country and, consequently, in affecting a country's energy use and CO2 emissions. This study applies input-output techniques to the Brazilian economy to evaluate the total impacts of international trade on its energy use and CO2 emissions. A commodity-by-industry IO model in hybrid units (energy commodities in physical units and non-energy commodities in monetary units) is applied to the Brazilian economy in 1995. Results show that total energy embodied in the exports of non-energy goods of Brazil equals 831 PJ, while total carbon embodied is 13.5 MtC. These amounts are larger than the relevant amounts embodied in the imports of non-energy goods, respectively 679 PJ and 9.9 MtC. These figures are better understood by contrasting them with the total energy use and the corresponding total carbon emissions of the Brazilian economy in 1995 estimated by this work: 6781 PJ and 99.4 MtC, respectively. This means that international inflows and outflows of energy embodied in non-energy goods are in the order of 10 and 12% of the total energy use, while inflows and outflows of carbon embodied in non-energy goods are approximately 10 and 14% of the corresponding total carbon emissions of the Brazilian economy in 1995. The general picture is that Brazil is not only a net exporter of energy (153 PJ) and of carbon (3.6 MtC) embodied in the non-energy goods internationally traded by the country in 1995, but also that each dollar earned with exports embodied 40% more energy and 56% more carbon than each dollar spent on imports. These findings suggest that Brazilian policy-makers should be concerned about the extra impacts international trade policy may have on energy use and carbon emissions of the country. 71 refs

Carbon nanomaterials in biological systems

Energy Technology Data Exchange (ETDEWEB)

Pu Chun Ke [Laboratory of Single-Molecule Biophysics and Polymer Physics, Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Qiao Rui [Department of Mechanical Engineering, Clemson University, Clemson, SC 29634 (United States)

2007-09-19

This paper intends to reflect, from the biophysical viewpoint, our current understanding on interfacing nanomaterials, such as carbon nanotubes and fullerenes, with biological systems. Strategies for improving the solubility, and therefore, the bioavailability of nanomaterials in aqueous solutions are summarized. In particular, the underlining mechanisms of attaching biomacromolecules (DNA, RNA, proteins) and lysophospholipids onto carbon nanotubes and gallic acids onto fullerenes are analyzed. The diffusion and the cellular delivery of RNA-coated carbon nanotubes are characterized using fluorescence microscopy. The translocation of fullerenes across cell membranes is simulated using molecular dynamics to offer new insight into the complex issue of nanotoxicity. To assess the fate of nanomaterials in the environment, the biomodification of lipid-coated carbon nanotubes by the aquatic organism Daphnia magna is discussed. The aim of this paper is to illuminate the need for adopting multidisciplinary approaches in the field study of nanomaterials in biological systems and in the environment. (topical review)

Carbon nanomaterials in biological systems

International Nuclear Information System (INIS)

Pu Chun Ke; Qiao Rui

2007-01-01

This paper intends to reflect, from the biophysical viewpoint, our current understanding on interfacing nanomaterials, such as carbon nanotubes and fullerenes, with biological systems. Strategies for improving the solubility, and therefore, the bioavailability of nanomaterials in aqueous solutions are summarized. In particular, the underlining mechanisms of attaching biomacromolecules (DNA, RNA, proteins) and lysophospholipids onto carbon nanotubes and gallic acids onto fullerenes are analyzed. The diffusion and the cellular delivery of RNA-coated carbon nanotubes are characterized using fluorescence microscopy. The translocation of fullerenes across cell membranes is simulated using molecular dynamics to offer new insight into the complex issue of nanotoxicity. To assess the fate of nanomaterials in the environment, the biomodification of lipid-coated carbon nanotubes by the aquatic organism Daphnia magna is discussed. The aim of this paper is to illuminate the need for adopting multidisciplinary approaches in the field study of nanomaterials in biological systems and in the environment. (topical review)

DATA MINING AT THE NEBRASKA OIL & GAS COMMISSION

Energy Technology Data Exchange (ETDEWEB)

James R. Weber

2001-05-01

The purpose of this study of the hearing records is to identify factors that are likely to impact the performance of a waterflood in the Nebraska panhandle. The records consisted of 140 cases. Most of the hearings were held prior to 1980. Many of the records were incomplete, and data believed to be key to estimating waterflood performance such as Dykstra-Parson permeability distribution or relative permeability were absent. New techniques were applied to analyze the sparse, incomplete dataset. When information is available, but not clearly understood, new computational intelligence tools can decipher correlations in the dataset. Fuzzy ranking and neural networks were the tools used to estimate secondary recovery from the Cliff Farms Unit. The hearing records include 30 descriptive entries that could influence the success or failure of a waterflood. Success or failure is defined by the ratio of secondary to primary oil recovery (S/P). Primary recovery is defined as cumulative oil produced at the time of the hearing and secondary recovery is defined as the oil produced since the hearing date. Fuzzy ranking was used to prioritize the relevance of 6 parameters on the outcome of the proposed waterflood. The 6 parameters were universally available in 44 of the case hearings. These 44 cases serve as the database used to correlate the following 6 inputs with the respective S/P. (1) Cumulative Water oil ratio, bbl/bbl; (2) Cumulative Gas oil ratio, mcf/bbl; (3) Unit area, acres; (4) Average Porosity, %; (5) Average Permeability, md; (6) Initial bottom hole pressure, psi. A 6-3-1 architecture describes the neural network used to develop a correlation between the 6 input parameters and their respective S/P. The network trained to a 85% correlation coefficient. The predicted Cliff Farms Unit S/P is 0.315 or secondary recovery is expected to be 102,700 bbl.

Some characteristics in operation of long exploited oil fields in Fergana depression. [USSR

Energy Technology Data Exchange (ETDEWEB)

Gordinskii, E V; Ovanesov, M G; Irmatov, E K

1969-01-01

A review of geological and oil production data from 3 Fergana fields is presented. The reservoirs are small, tectonically bounded, and are anticlines of Paleogenic carbonates. Reservoirs are heterogeneous with porosity ranging from 3 to 25% and permeability ranging from a few to 500 md. Some of the reservoirs have expanding gas caps, some are solution drive, and others have been waterflooded. All are now in the final stage of depletion. Production history and characteristics of each group are given. One way of increasing present production rate appears to be injection of gas or air into the reservoirs. This can be done inexpensively, since additional injection wells would not have to be drilled and some produced gas is available. Increased fluid withdrawal from present wells should also be beneficial.

Incorrectly Interpreting the Carbon Mass Balance Technique Leads to Biased Emissions Estimates from Global Vegetation Fires

Science.gov (United States)

Surawski, N. C.; Sullivan, A. L.; Roxburgh, S. H.; Meyer, M.; Polglase, P. J.

2016-12-01

Vegetation fires are a complex phenomenon and have a range of global impacts including influences on climate. Even though fire is a necessary disturbance for the maintenance of some ecosystems, a range of anthropogenically deleterious consequences are associated with it, such as damage to assets and infrastructure, loss of life, as well as degradation to air quality leading to negative impacts on human health. Estimating carbon emissions from fire relies on a carbon mass balance technique which has evolved with two different interpretations in the fire emissions community. Databases reporting global fire emissions estimates use an approach based on `consumed biomass' which is an approximation to the biogeochemically correct `burnt carbon' approach. Disagreement between the two methods occurs because the `consumed biomass' accounting technique assumes that all burnt carbon is volatilized and emitted. By undertaking a global review of the fraction of burnt carbon emitted to the atmosphere, we show that the `consumed biomass' accounting approach overestimates global carbon emissions by 4.0%, or 100 Teragrams, annually. The required correction is significant and represents 9% of the net global forest carbon sink estimated annually. To correctly partition burnt carbon between that emitted to the atmosphere and that remaining as a post-fire residue requires the post-burn carbon content to be estimated, which is quite often not undertaken in atmospheric emissions studies. To broaden our understanding of ecosystem carbon fluxes, it is recommended that the change in carbon content associated with burnt residues be accounted for. Apart from correctly partitioning burnt carbon between the emitted and residue pools, it enables an accounting approach which can assess the efficacy of fire management operations targeted at sequestering carbon from fire. These findings are particularly relevant for the second commitment period for the Kyoto protocol, since improved landscape fire

An Entropy Approach to Regional Differences in Carbon Dioxide Emissions: Implications for Ethanol Usage

Directory of Open Access Journals (Sweden)

Dong Hee Suh

2018-01-01

Full Text Available The growth of the U.S. economy has been accompanied with a significant rise in carbon dioxide (CO2 emissions. As CO2 emissions are dependent on regional climatic conditions and energy-related activities in states, this study examines the extent to which the distribution of CO2 emissions vary across nine climatically consistent regions in the U.S. The results obtained from the entropy approach reveal that the inequalities of CO2 emissions vary across the regions. While the total inequality of CO2 emissions is determined by the between-region and the average within-region inequalities, the between-region inequality begins to dominate the average within-region inequalities around 1980s; the emission inequalities between regions increase, but those within each region decrease. Given that ethanol usage is relevant to energy-related CO2 emissions, this study also evaluates the impact of ethanol usage on the changes in the emission inequalities. The results show that an increase in the ratio of ethanol to fossil fuels is associated closely with the reductions in the inequalities of CO2 emissions.

Building low carbon communities in China: The role of individual’s behaviour change and engagement

International Nuclear Information System (INIS)

Jiang, Ping; Chen, Yihui; Xu, Bin; Dong, Wenbo; Kennedy, Erin

2013-01-01

Low carbon sustainability has been addressed in China’s national development strategies. This research explores individual behaviour change and engagement in building low carbon communities in China through a case study looking at the building of a low carbon campus at Fudan University, Shanghai. Individual behaviour directly influences the overall energy consumption and carbon emissions on Fudan University’s campus. Even though relevant polices have been issued for energy conservation, the energy consumption increased by 5% every year, which suggests that the “top-down” approach telling students and staff “what to do” does not work effectively. Based on a comprehensive method which includes the individual and social aspects related to the energy behaviour, the research analyses the promotion of individual engagement in building a low carbon campus through behaviour change based on four main aspects: (1) awareness raising and behaviour forming; (2) approaches to encourage behaviour change; (3) beyond the barriers and the constraints; and (4) systems and mechanisms for the long-term engagement. A low carbon management system is proposed for not only addressing management and technical solutions at the university level, but also based on the contributions from behaviour changes in establishing a low carbon campus at Fudan University at the individual level. - Highlights: • The “top-down” approach is not an effective way to building low carbon communities in China. • Individuals’ behaviour change and engagement play a key role in low carbon sustainability. • Awareness raising, proper approaches and sound mechanisms are necessary to encourage long-term behaviour changes. • An integrated management system is developed for comprehensibly establishing a low carbon campus at Fudan University

Three-Phase Carbon Fiber Amine Functionalized Carbon Nanotubes Epoxy Composite: Processing, Characterisation, and Multiscale Modeling

Directory of Open Access Journals (Sweden)

Kamal Sharma

2014-01-01

Full Text Available The present paper discusses the key issues of carbon nanotube (CNT dispersion and effect of functionalisation on the mechanical properties of multiscale carbon epoxy composites. In this study, CNTs were added in epoxy matrix and further reinforced with carbon fibres. Predetermined amounts of optimally amine functionalised CNTs were dispersed in epoxy matrix, and unidirectional carbon fiber laminates were produced. The effect of the presence of CNTs (1.0 wt% in the resin was reflected by pronounced increase in Young’s modulus, inter-laminar shear strength, and flexural modulus by 51.46%, 39.62%, and 38.04%, respectively. However, 1.5 wt% CNT loading in epoxy resin decreased the overall properties of the three-phase composites. A combination of Halpin-Tsai equations and micromechanics modeling approach was also used to evaluate the mechanical properties of multiscale composites and the differences between the predicted and experimental values are reported. These multiscale composites are likely to be used for potential missile and aerospace structural applications.

Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

Directory of Open Access Journals (Sweden)

Burmistrz Piotr

2016-01-01

Full Text Available The analysis of Carbon Footprint (CF for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ. The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA.

Carbon nanotubes for biological and biomedical applications

International Nuclear Information System (INIS)

Yang Wenrong; Thordarson, Pall; Gooding, J Justin; Ringer, Simon P; Braet, Filip

2007-01-01

Ever since the discovery of carbon nanotubes, researchers have been exploring their potential in biological and biomedical applications. The recent expansion and availability of chemical modification and bio-functionalization methods have made it possible to generate a new class of bioactive carbon nanotubes which are conjugated with proteins, carbohydrates, or nucleic acids. The modification of a carbon nanotube on a molecular level using biological molecules is essentially an example of the 'bottom-up' fabrication principle of bionanotechnology. The availability of these biomodified carbon nanotube constructs opens up an entire new and exciting research direction in the field of chemical biology, finally aiming to target and to alter the cell's behaviour at the subcellular or molecular level. This review covers the latest advances of bio-functionalized carbon nanotubes with an emphasis on the development of functional biological nano-interfaces. Topics that are discussed herewith include methods for biomodification of carbon nanotubes, the development of hybrid systems of carbon nanotubes and biomolecules for bioelectronics, and carbon nanotubes as transporters for a specific delivery of peptides and/or genetic material to cells. All of these current research topics aim at translating these biotechnology modified nanotubes into potential novel therapeutic approaches. (topical review)

Work-life balance

Energy Technology Data Exchange (ETDEWEB)

Roche, Pat

2011-03-15

Gay Renouf has opted for a work/life balance; with a chemistry degree she joined the Saskatchewan Research Council out of graduate school in 1986. She first worked on understanding surfactants in emulsions and then dealt more with petroleum engineering issues like pipeline specifications. She is looking at waterfloods in heavy and medium gravity pools and has discovered factors helping to produce heavy oil waterfloods. But all Renouf's life is not devoted to her work: she has been working part-time, spending her free time being a parent, training for marathons and being a running coach. Renouf believes that her passion for running is consistent with her work as a scientist.

Quantification of the "global" authigenic carbonate δ13C value and implications for carbon cycling

Science.gov (United States)

Loyd, S. J.

2017-12-01

Relationships among early Earth ocean chemistry, atmospheric chemistry and the evolution/radiation of life have been inferred from carbon isotope compositions (δ13C) of marine carbonates. Under steady-state conditions, the isotope compositions of marine carbonates reflect both the amount and δ13C of carbon entering and leaving the oceans. Recently the traditional "two-output" (marine carbonate and organic matter) mass-balance equation has been modified to include a third, authigenic carbonate output term. However, the formation mechanisms of authigenic carbonates remain poorly understood, particularly from a global prospective. The utility of the new mass-balance approach will be limited until authigenic carbonates are better characterized (e.g., through δ13C analyses). Authigenic carbonates form largely as a result of 1) the respiratory degradation of organic matter (e.g., sulfate reduction), 2) the oxidation of methane and 3) the production of methane. These major reaction pathways can produce authigenic carbonates with highly variable δ13C compositions (δ13Cac). Spatiotemporal variation in the extent and prevalence of different pathways therefore exert a first order control on "global" δ13Cac. Here, values are compiled from new and existing data sets and a modern, global δ13Cac is calculated. When calculated as an average of all data or an averaged mean of individual sites, this value is very similar to normal marine sedimentary organic matter. This finding suggests that marine sediments behave largely as closed systems in the context of organic matter degradation and carbonate authigenesis. In addition, the lack of significant difference between authigenic and organic δ13C implies that these two mass-balance output terms can be considered collectively in more recent time intervals. It may be appropriate to separate these two terms when characterizing more ancient settings when redox characteristics promoted more reducing organic matter degradation

Nanoscale Electrochemistry of sp(2) Carbon Materials: From Graphite and Graphene to Carbon Nanotubes.

Science.gov (United States)

Unwin, Patrick R; Güell, Aleix G; Zhang, Guohui

2016-09-20

Carbon materials have a long history of use as electrodes in electrochemistry, from (bio)electroanalysis to applications in energy technologies, such as batteries and fuel cells. With the advent of new forms of nanocarbon, particularly, carbon nanotubes and graphene, carbon electrode materials have taken on even greater significance for electrochemical studies, both in their own right and as components and supports in an array of functional composites. With the increasing prominence of carbon nanomaterials in electrochemistry comes a need to critically evaluate the experimental framework from which a microscopic understanding of electrochemical processes is best developed. This Account advocates the use of emerging electrochemical imaging techniques and confined electrochemical cell formats that have considerable potential to reveal major new perspectives on the intrinsic electrochemical activity of carbon materials, with unprecedented detail and spatial resolution. These techniques allow particular features on a surface to be targeted and models of structure-activity to be developed and tested on a wide range of length scales and time scales. When high resolution electrochemical imaging data are combined with information from other microscopy and spectroscopy techniques applied to the same area of an electrode surface, in a correlative-electrochemical microscopy approach, highly resolved and unambiguous pictures of electrode activity are revealed that provide new views of the electrochemical properties of carbon materials. With a focus on major sp(2) carbon materials, graphite, graphene, and single walled carbon nanotubes (SWNTs), this Account summarizes recent advances that have changed understanding of interfacial electrochemistry at carbon electrodes including: (i) Unequivocal evidence for the high activity of the basal surface of highly oriented pyrolytic graphite (HOPG), which is at least as active as noble metal electrodes (e.g., platinum) for outer

Technical Report: Investigation of Carbon Cycle Processes within a Managed Landscape: An Ecosystem Manipulation and Isotope Tracer Approach

Energy Technology Data Exchange (ETDEWEB)

Griffis, Timothy J; Baker, John M; Billmark, Kaycie

2009-06-01

The goal of this research is to provide a better scientific understanding of carbon cycle processes within an agricultural landscape characteristic of the Upper Midwest. This project recognizes the need to study processes at multiple spatial and temporal scales to reduce uncertainty in ecosystem and landscape-scale carbon budgets to provide a sound basis for shaping future policy related to carbon management. Specifically, this project has attempted to answer the following questions: 1. Would the use of cover crops result in a shift from carbon neutral to significant carbon gain in corn-soybean rotation ecosystems of the Upper Midwest? 2. Can stable carbon isotope analyses be used to partition ecosystem respiration into its autotrophic and heterotrophic components? 3. Can this partitioning be used to better understand the fate of crop residues to project changes in the soil carbon reservoir? 4. Are agricultural ecosystems of the Upper Midwest carbon neutral, sinks, or sources? Can the proposed measurement and modeling framework help address landscape-scale carbon budget uncertainties and help guide future carbon management policy?

Energy Saving High-Capacity Moderate Pressure Carbon Dioxide Storage System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Our approach to high-pressure carbon dioxide storage will directly address the challenges associated with storage of compressed carbon dioxide - the need to reduce...

Influence of soil sampling approaches in the evaluation of soil organic carbon stocks under different land uses in a Mediterranean area

Science.gov (United States)

Francaviglia, Rosa; Doro, Luca; Ledda, Luigi; Parras-Alcántara, Luis; Lozano-García, Beatriz

2016-04-01

Different approaches of soil sampling can provide significantly different estimates of soil organic carbon stocks (SOCs) (Parras-Alcántara et al., 2015a). Many studies have focused on SOC distribution only in the biologically active layers of topsoil, the IPCC carbon accounting method estimates the change in SOC storage for the top 30 cm of a soil profile, and indeed limited data are available for SOCs below this depth. Moreover, SOC estimates are more uncertain in areas with heterogeneous land uses and pedoclimatic conditions such as Mediterranean environments, which are more prone to land degradation due to SOC degradation and depletion and erosive processes (Muñoz-Rojas et al., 2015). Anyhow, the open question is whether soil should be sampled following the pedogenetic horizons with soil entire soil approach (ESP), or along fixed depth increments using the soil control section method (SCS) (Parras-Alcántara et al., 2015b). In addition, SOCs are often not adjusted for the soil volume occupied by coarse fragments as recommended by the IPCC Good Practice Guidance for LULUCF (IPCC, 2003) accordingly to the equation: SOCs = SOC (g kg-1) × bulk density (Mg m-3) × depth (m) × (1 - coarse fragment) × 10. The work deals with the comparison of SOCs using the ESP and SCS approaches, applied to a study area of northeastern Sardinia (Italy) under typical agro-silvo-pastoral systems (Francaviglia et al., 2014). The area lies within a hilly basin where elevation is in the range 275-340 m a.s.l., and slope ranges from 2-6% to 16-30%. The local climate is warm temperate with dry and hot summers, mean annual rainfall is 623 mm (range 367-811mm) and mean annual temperature is 15.0° C (13.8-16.4° C). The area has the same soil type (Haplic Endoleptic Cambisols, Dystric) according to IUSS Working Group WRB (2006), and the following land uses with different levels of cropping intensification were compared: Tilled vineyards (Tv), No-tilled grassed vineyards (Ntgv), Hay crop

Electron diffraction from carbon nanotubes

International Nuclear Information System (INIS)

Qin, L-C

2006-01-01

The properties of a carbon nanotube are dependent on its atomic structure. The atomic structure of a carbon nanotube can be defined by specifying its chiral indices (u, v), that specify its perimeter vector (chiral vector), with which the diameter and helicity are also determined. The fine electron beam available in a modern transmission electron microscope (TEM) offers a unique probe to reveal the atomic structure of individual nanotubes. This review covers two aspects related to the use of the electron probe in the TEM for the study of carbon nanotubes: (a) to understand the electron diffraction phenomena for inter-pretation of the electron diffraction patterns of carbon nanotubes and (b) to obtain the chiral indices (u, v), of the carbon nanotubes from the electron diffraction patterns. For a nanotube of a given structure, the electron scattering amplitude from the carbon nanotube is first described analytically in closed form using the helical diffraction theory. From a known structure as given by the chiral indices (u, v), its electron diffraction pattern can be calculated and understood. The reverse problem, i.e. assignment of the chiral indices from an electron diffraction pattern of a carbon nanotube, is approached from the relationship between the electron scattering intensity distribution and the chiral indices (u, v). We show that electron diffraction patterns can provide an accurate and unambiguous assignment of the chiral indices of carbon nanotubes. The chiral indices (u, v) can be read indiscriminately with a high accuracy from the intensity distribution on the principal layer lines in an electron diffraction pattern. The symmetry properties of electron diffraction from carbon nanotubes and the electron diffraction from deformed carbon nanotubes are also discussed in detail. It is shown that 2mm symmetry is always preserved for single-walled carbon nanotubes, but it can break down for multiwalled carbon nanotubes under some special circumstances

Production of palm kernel shell-based activated carbon by direct physical activation for carbon dioxide adsorption.

Science.gov (United States)

Rashidi, Nor Adilla; Yusup, Suzana

2018-05-09

The feasibility of biomass-based activated carbons has received a huge attention due to their excellent characteristics such as inexpensiveness, good adsorption behaviour and potential to reduce a strong dependency towards non-renewable precursors. Therefore, in this research work, eco-friendly activated carbon from palm kernel shell that has been produced from one-stage physical activation by using the Box-Behnken design of Response Surface Methodology is highlighted. The effect of three input parameters-temperature, dwell time and gas flow rate-towards product yield and carbon dioxide (CO 2 ) uptake at room temperature and atmospheric pressure are studied. Model accuracy has been evaluated through the ANOVA analysis and lack-of-fit test. Accordingly, the optimum condition in synthesising the activated carbon with adequate CO 2 adsorption capacity of 2.13 mmol/g and product yield of 25.15 wt% is found at a temperature of 850 °C, holding time of 60 min and CO 2 flow rate of 450 cm 3 /min. The synthesised activated carbon has been characterised by diverse analytical instruments including thermogravimetric analyser, scanning electron microscope, as well as N 2 adsorption-desorption isotherm. The characterisation analysis indicates that the synthesised activated carbon has higher textural characteristics and porosity, together with better thermal stability and carbon content as compared to pristine palm kernel shell. Activated carbon production via one-step activation approach is economical since its carbon yield is within the industrial target, whereas CO 2 uptake is comparable to the synthesised activated carbon from conventional dual-stage activation, commercial activated carbon and other published data from literature.

Bending of metal-filled carbon nanotube under electron beam irradiation

Directory of Open Access Journals (Sweden)

Abha Misra

2012-03-01

Full Text Available Electron beam irradiation induced, bending of Iron filled, multiwalled carbon nanotubes is reported. Bending of both the carbon nanotube and the Iron contained within the core was achieved using two approaches with the aid of a high resolution electron microscope (HRTEM. In the first approach, bending of the nanotube structure results in response to the irradiation of a pristine kink defect site, while in the second approach, disordered sites induce bending by focusing the electron beam on the graphite walls. The HRTEM based in situ observations demonstrate the potential for using electron beam irradiation to investigate and manipulate the physical properties of confined nanoscale structures.

Approach to voxel-based carbon stock quanticiation using LiDAR data in tropical rainforest, Brunei

Science.gov (United States)

Kim, Eunji; Piao, Dongfan; Lee, Jongyeol; Lee, Woo-Kyun; Yoon, Mihae; Moon, Jooyeon

2016-04-01

Forest is an important means to adapt climate change as the only carbon sink recognized by the international community (KFS 2009). According to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), Agriculture, Forestry, and Other Land Use (AFOLU) sectors including forestry contributed 24% of total anthropogenic emissions in 2010 (IPCC 2014; Tubiello et al. 2015). While all sectors excluding AFOLU have increased Greenhouse Gas (GHG) emissions, land use sectors including forestry remains similar level as before due to decreasing deforestation and increasing reforestation. In earlier researches, optical imagery has been applied for analysis (Jakubowski et al. 2013). Optical imagery collects spectral information in 2D. It is difficult to effectively quantify forest stocks, especially in dense forest (Cui et al. 2012). To detect individual trees information from remotely sensed data, Light detection and ranging (LiDAR) has been used (Hyyppäet al. 2001; Persson et al. 2002; Chen et al. 2006). Moreover, LiDAR has the ability to actively acquire vertical tree information such as tree height using geo-registered 3D points (Kwak et al. 2007). In general, however, geo-register 3D point was used with a raster format which contains only 2D information by missing all the 3D data. Therefore, this research aimed to use the volumetric pixel (referred as "voxel") approach using LiDAR data in tropical rainforest, Brunei. By comparing the parameters derived from voxel based LiDAR data and field measured data, we examined the relationships between them for the quantification of forest carbon. This study expects to be more helpful to take advantage of the strategic application of climate change adaption.

Final technical report: Certification of low carbon farming practices

OpenAIRE

TUOMISTO HANNA LEENA; ANGILERI Vincenzo; DE CAMILLIS CAMILLO; LOUDJANI Philippe; PELLETIER NATHANIEL; HAASTRUP Palle; NISINI SCACCHIAFICHI Luigi

2013-01-01

In 2010, the European Parliament asked the European Commission to carry out a pilot project on the “certification of low-carbon farming practices in the European Union” to promote reductions of GHG emissions from farming. The overall aim of the project was to assess how efforts of European farmers to produce agricultural products with carbon-neutral or low-carbon-footprint farming practices might be incorporated into policy approaches (possibly via certification), so as to promote the reducti...

A novel direct carbon fuel cell by approach of tubular solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Zeng, Fanrong; Wang, Shaorong; Wen, Tinglian; Wen, Zhaoyin [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Inorganic Energy Materials and Power Source Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

2010-01-15

A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO-YSZ anode support tube, a NiO-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm{sup -2} at 850, 800, and 750 C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells. (author)

Strongly coupled inorganic-nano-carbon hybrid materials for energy storage.

Science.gov (United States)

Wang, Hailiang; Dai, Hongjie

2013-04-07

The global shift of energy production from fossil fuels to renewable energy sources requires more efficient and reliable electrochemical energy storage devices. In particular, the development of electric or hydrogen powered vehicles calls for much-higher-performance batteries, supercapacitors and fuel cells than are currently available. In this review, we present an approach to synthesize electrochemical energy storage materials to form strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and novel graphitic nano-carbon materials such as carbon nanotubes and graphene, through nucleation and growth of nanoparticles at the functional groups of oxidized graphitic nano-carbon. We show that the inorganic-nano-carbon hybrid materials represent a new approach to synthesize electrode materials with higher electrochemical performance than traditional counterparts made by simple physical mixtures of electrochemically active inorganic particles and conducting carbon materials. The inorganic-nano-carbon hybrid materials are novel due to possible chemical bonding between inorganic nanoparticles and oxidized carbon, affording enhanced charge transport and increased rate capability of electrochemical materials without sacrificing specific capacity. Nano-carbon with various degrees of oxidation provides a novel substrate for nanoparticle nucleation and growth. The interactions between inorganic precursors and oxidized-carbon substrates provide a degree of control over the morphology, size and structure of the resulting inorganic nanoparticles. This paper reviews the recent development of inorganic-nano-carbon hybrid materials for electrochemical energy storage and conversion, including the preparation and functionalization of graphene sheets and carbon nanotubes to impart oxygen containing groups and defects, and methods of synthesis of nanoparticles of various morphologies on oxidized graphene and carbon nanotubes. We then review the applications of the SC

Recovery of Waterflood Residual Oil Using Alkali, Surfactant and Polymer Slugs in Radial Cores Récupération d'huile résiduelle par injection d'eau améliorée de produits alcalins, de tensio-actifs et de polymères dans des carottes radiales

Directory of Open Access Journals (Sweden)

Nasr-El-Din H. A.

2006-11-01

Full Text Available An experimental study has been conducted to examine mobilization and recovery of waterflood residual oil in radial cores. Alkali, surfactant, and polymer slugs of various compositions, sizes and sequences were tested. Core flood experiments were conducted with unfired radial Berea sandstone disks at a flow rate of 8 cm3/h. David Lloydminster crude oil (total acid number of 0. 45 mg KOH/g oil was used. The results of the present work showed that the composition and sequence of the injected chemical slug play an important role in mobilization and recovery of residual oil. For slugs lacking either mobility control, or low interfacial tension, no oil bank was formed and tertiary oil recovery was less than 20% Sor. A significant oil bank and tertiary oil recovery up to 70 % Sor were obtained with slugs having mobility control and low interfacial tension. However, maximum oil cut, incre-mental oil recovery and surfactant propagation were found to be functions of the alkali content in the slug. The incremental oil recovery, oil cut and slug injectivity greatly improved as the alkali concentration (sodium carbonate in the combined slug was increased. A slight delay in surfactant breakthrough and a significantly slower rate of surfactant propagation were observed at higher sodium carbonate concentrations. Une étude expérimentale ayant pour but d'examiner la mobilisation et la récupération assistée d'huile résiduelle, à la suite d'un déplacement par l'eau en milieu poreux, a été conduite. Des bouchons de produit alcalin, de surfactant et de polymère, ayant des compositions, grosseurs et séquences d'injection variées, furent essayés. Les déplacements en milieu poreux furent conduits en utilisant des carottes de grès berea (non traités à haute température et un débit de 8,0 cm3/h. Pour ce faire, on utilisa de l'huile de David Lloydminster (ayant un nombre acide de 0,45 mg KOH/g d'huile. Les résultats de ce travail ont démontré que la

Equal exchange: Determining a fair price for carbon

Energy Technology Data Exchange (ETDEWEB)

Hodes, G.; Kamel, S.

2007-12-14

This first volume in the new series CD4CDM Perspective Series focuses on determining an equal exchange between carbon buyers and sellers in CDM transactions. Contributors to this volume represent a wide spectrum of the various market actors that are interacting in order to realize both successful and equitable carbon transactions. The following issues are discussed: Global carbon price dynamics; CDM project risk profiles and/or premiums; Importance of time factors and delivery guarantees; Impact of regulatory drivers and post-Kyoto outlook; Region-specific outlooks; Strategies, contracting models and approaches. (BA)

Uncertainties and novel prospects in the study of the soil carbon dynamics

International Nuclear Information System (INIS)

Yang Wang; Yuch-Ping Hsieh

2002-01-01

Establishment of the Kyoto Protocol has resulted in an effort to look towards living biomass and soils for carbon sequestration. In order for carbon credits to be meaningful, sustained carbon sequestration for decades or longer is required. It has been speculated that improved land management could result in sequestration of a substantial amount of carbon in soils within several decades and therefore can be an important option in reducing atmospheric CO 2 concentration. However, evaluation of soil carbon sources and sinks is difficult because the dynamics of soil carbon storage and release is complex and still not well understood. There has been rapid development of quantitative techniques over the past two decades for measuring the component fluxes of the global carbon cycle and for studying the soil carbon cycle. Most significant development in the soil carbon cycle study is the application of accelerator mass spectrometry (AMS) in radiocarbon measurements. This has made it possible to unravel rates of carbon cycling in soils, by studying natural levels of radiocarbon in soil organic matter and soil CO 2 . Despite the advances in the study of the soil carbon cycle in the recent decades, tremendous uncertainties exist in the sizes and turnover times of soil carbon pools. The uncertainties result from lack of standard methods and incomplete understanding of soil organic carbon dynamics, compounded by natural variability in soil carbon and carbon isotopic content even within the same ecosystem. Many fundamental questions concerning the dynamics of the soil carbon cycle have yet to be answered. This paper reviews and synthesizes the isotopic approaches to the study of the soil carbon cycle. We will focus on uncertainties and limitations associated with these approaches and point out areas where more research is needed to improve our understanding of this important component of the global carbon cycle. (author)

Preparation and Characterization of Lanthanum Carbonate Octahydrate for the Treatment of Hyperphosphatemia

Directory of Open Access Journals (Sweden)

Anqi He

2013-01-01

Full Text Available We proposed a new approach to prepare lanthanum carbonate via reactions between lanthanum chloride and NaHCO3. In the reaction, small amount of NaHCO3 solution was firstly added to the acidic lanthanum chloride solution to generate lanthanum carbonate nuclei and then NaHCO3 is added to the lanthanum chloride at a constant speed. This approach makes both precipitation reaction and neutralization reaction take place simultaneously. Consequently, lanthanum carbonate is produced at low pH environment (pH below 4.0 so that the risk of generating lanthanum carbonate hydroxide is reduced. The product of the above reaction is validated by EDTA titration, elemental analysis, and XRD characterization. In addition, we established a FTIR spectroscopic method to identify La(OHCO3 from La2(CO32·8H2O. Lanthanum carbonate exhibits considerable ability to bind phosphate.

Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah

International Nuclear Information System (INIS)

Allison, M. Lee; Chidsey, Thomas Jr.

1999-01-01

The primary objective of this project is to enhance domestic petroleum production by demonstration and technology transfer of an advanced oil recovery technology in the Paradox basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to about 100 additional small fields in the Paradox basin alone, and result in increased recovery of 150 to 200 million bbl of oil. This project is designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon dioxide-(CO-) flood 2 project. The field demonstration, monitoring of field performance, and associated validation activities will take place in the Paradox basin within the Navajo Nation. The results of this project will be transferred to industry and other researchers through a petroleum extension service, creation of digital databases for distribution, technical workshops and seminars, field trips, technical presentations at national and regional professional meetings, and publication in newsletters and various technical or trade journals

Using 50 years of soil radiocarbon data to identify optimal approaches for estimating soil carbon residence times

Energy Technology Data Exchange (ETDEWEB)

Baisden, W.T., E-mail: t.baisden@gns.cri.nz [National Isotope Centre, GNS Science, P.O. Box 31312, Lower Hutt (New Zealand); Canessa, S. [National Isotope Centre, GNS Science, P.O. Box 31312, Lower Hutt (New Zealand)

2013-01-15

In 1959, Athol Rafter began a substantial programme of systematically monitoring the flow of {sup 14}C produced by atmospheric thermonuclear tests through organic matter in New Zealand soils under stable land use. A database of {approx}500 soil radiocarbon measurements spanning 50 years has now been compiled, and is used here to identify optimal approaches for soil C-cycle studies. Our results confirm the potential of {sup 14}C to determine residence times, by estimating the amount of 'bomb {sup 14}C' incorporated. High-resolution time series confirm this approach is appropriate, and emphasise that residence times can be calculated routinely with two or more time points as little as 10 years apart. This approach is generally robust to the key assumptions that can create large errors when single time-point {sup 14}C measurements are modelled. The three most critical assumptions relate to: (1) the distribution of turnover times, and particularly the proportion of old C ('passive fraction'), (2) the lag time between photosynthesis and C entering the modelled pool, (3) changes in the rates of C input. When carrying out approaches using robust assumptions on time-series samples, multiple soil layers can be aggregated using a mixing equation. Where good archived samples are available, AMS measurements can develop useful understanding for calibrating models of the soil C cycle at regional to continental scales with sample numbers on the order of hundreds rather than thousands. Sample preparation laboratories and AMS facilities can play an important role in coordinating the efficient delivery of robust calculated residence times for soil carbon.

Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

Institute of Scientific and Technical Information of China (English)

Yu; Han; Li; Caige

2016-01-01

Targeted at the dynamic demands in the rapid urban construction, the planning technology strategy of the Shenzhen International Low Carbon City studies the fl exible index model based on carbon emission evaluation, and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment. Meanwhile, it also evaluates the application of low carbon technology and gives feedback in time, so as to constantly optimize and complete the low carbon city planning. In detail, it involves industrial planning, ecological restoration, transport planning, energy resource planning, architectural design, etc., for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages. The quick-response and fl exible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development, thus realizing the sustainable leap-forward development and providing reference for other similar regions.

Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

Institute of Scientific and Technical Information of China (English)

Yu Han; Li Caige

2016-01-01

Targeted at the dynamic demands in the rapid urban construction,the planning technology strategy of the Shenzhen International Low Carbon City studies the flexible index model based on carbon emission evaluation,and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment.Meanwhile,it also evaluates the application of low carbon technology and gives feedback in time,so as to constantly optimize and complete the low carbon city planning.In detail,it involves industrial planning,ecological restoration,transport planning,energy resource planning,architectural design,etc.,for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages.The quick-response and flexible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development,thus realizing the sustainable leap-forward development and providing reference for other similar regions.

Ultrahigh surface area carbon from carbonated beverages: Combining self-templating process and in situ activation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengfei; Zhang, Zhiyong; Chen, Jihua; Dai, Sheng

2015-11-01

Ultrahigh surface area carbons (USACs, e.g., >2000 m2/g) are attracting tremendous attention due to their outstanding performance in energy-related applications. The state-of-art approaches to USACs involve templating or activation methods and all these techniques show certain drawbacks. In this work, a series of USACs with specific surface areas up to 3633 m2/g were prepared in two steps: hydrothermal carbonization (200 °C) of carbonated beverages (CBs) and further thermal treatment in nitrogen (600–1000 °C). The rich inner porosity is formed by a self-templated process during which acids and polyelectrolyte sodium salts in the beverage formulas make some contribution. This strategy covers various CBs such as Coca Cola®, Pepsi Cola®, Dr. Pepper®, and Fanta® and it enables an acceptable product yield (based on sugars), for example: 21 wt% for carbon (2940 m2/g) from Coca Cola®. Being potential electrode materials for supercapacitors, those carbon materials possessed a good specific capacitance (57.2–185.7 F g-1) even at a scan rate of 1000 mV s-1. Thus, a simple and efficient strategy to USACs has been presented.

Sustainable operations management: A typological approach

Directory of Open Access Journals (Sweden)

Lawrence Michael Corbett

2009-07-01

Full Text Available This paper discusses the nature of sustainability and sustainable development as they relate to operations management. It proposes a typology for sustainable operations management that is based on the life cycle stages of a product and the three dimensions of corporate social responsibility. The aim is to show how this typology development could provide a useful approach to integrating the diverse strands of sustainability in operations, using industrial ecology and carbon neutrality as examples. It does this by providing a focused subset of environmental concerns for an industrial ecology approach, and some research propositions for the issue of carbon neutrality.

Filled carbon nanotubes in biomedical imaging and drug delivery.

Science.gov (United States)

Martincic, Markus; Tobias, Gerard

2015-04-01

Carbon nanotubes have been advocated as promising candidates in the biomedical field in the areas of diagnosis and therapy. In terms of drug delivery, the use of carbon nanotubes can overcome some limitations of 'free' drugs by improving the formulation of poorly water-soluble drugs, allowing targeted delivery and even enabling the co-delivery of two or more drugs for combination therapy. Two different approaches are currently being explored for the delivery of diagnostic and therapeutic agents by carbon nanotubes, namely attachment of the payload to the external sidewalls or encapsulation into the inner cavities. Although less explored, the latter confers additional stability to the chosen diagnostic or therapeutic agents, and leaves the backbone structure of the nanotubes available for its functionalization with dispersing and targeting moieties. Several drug delivery systems and diagnostic agents have been developed in the last years employing the inner tubular cavities of carbon nanotubes. The research discussed in this review focuses on the use of carbon nanotubes that contain in their interior drug molecules and diagnosis-related compounds. The approaches employed for the development of such nanoscale vehicles along with targeting and releasing strategies are discussed. The encapsulation of both biomedical contrast agents and drugs inside carbon nanotubes is further expanding the possibilities to allow an early diagnosis and treatment of diseases.

PV water pumping for carbon sequestration in dry land agriculture

International Nuclear Information System (INIS)

Olsson, Alexander; Campana, Pietro Elia; Lind, Mårten; Yan, Jinyue

2015-01-01

Highlights: • A novel model for carbon sequestration in dry land agriculture is developed. • We consider the water-food-energy-climate nexus to assess carbon sequestration. • Using water for carbon sequestration should be assessed critically. • Co-benefits of carbon sequestration should be included in the assessment. • Moisture feedback is part of the nexus model. - Abstract: This paper suggests a novel model for analysing carbon sequestration activities in dry land agriculture considering the water-food-energy-climate nexus. The paper is based on our on-going studies on photovoltaic water pumping (PVWP) systems for irrigation of grasslands in China. Two carbon sequestration projects are analysed in terms of their water productivity and carbon sequestration potential. It is concluded that the economic water productivity, i.e. how much water that is needed to produce an amount of grass, of grassland restoration is low and that there is a need to include several of the other co-benefits to justify the use of water for climate change mitigation. The co-benefits are illustrated in a nexus model including (1) climate change mitigation, (2) water availability, (3) downstream water impact, (4) energy security, (5) food security and (6) moisture recycling. We argue for a broad approach when analysing water for carbon sequestration. The model includes energy security and food security together with local and global water concerns. This makes analyses of dry land carbon sequestration activities more relevant and accurate. Without the nexus approach, the co-benefits of grassland restoration tend to be diminished

Development of electrically heated rods with resistive element of graphite or carbon/carbon composites for simulating transients in nuclear reactors

International Nuclear Information System (INIS)

Polidoro, H.A.

1987-01-01

Thermo-hydraulic problems, in nuclear plants are normally analysed by the use of electrically heated rods. The direct or indirect heater rods are limited in their use because, for high temperatures and high heat flux, the heating element temperature approach its melting point. The use of platinum or tantalum is not economically viable. Graphite and carbon/carbon composites are alternative materials because they are good electrical conductors and have good mechanical properties at high temperatures. Graphite and carbon/carbon composites were used to make heating elements for testing by indirect heating. The swaging process used to reduce the cladding diameter prevented the fabrication of graphite heater rods. Carbon/carbon composite used to make heating elements gave good results up to a heat flux of 100 W/cm 2 . It is easy to verify that this value can be exceeded if the choice of the complementary materials for insulator and cladding improved. (author) [pt

Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst

Directory of Open Access Journals (Sweden)

Istadi Istadi

2011-11-01

Full Text Available Major problem in CO2 reforming of methane (CORM process is coke formation which is a carbonaceous residue that can physically cover active sites of a catalyst surface and leads to catalyst deactivation. A key to develop a more coke-resistant catalyst lies in a better understanding of the methane reforming mechanism at a molecular level. Therefore, this paper is aimed to simulate a micro-kinetic approach in order to calculate coking rate in CORM reaction. Rates of encapsulating and filamentous carbon formation are also included. The simulation results show that the studied catalyst has a high activity, and the rate of carbon formation is relatively low. This micro-kinetic modeling approach can be used as a tool to better understand the catalyst deactivation phenomena in reaction via carbon deposition. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 10th May 2011; Revised: 16th August 2011; Accepted: 27th August 2011[How to Cite: I. Istadi, D.D. Anggoro, N.A.S. Amin, and D.H.W. Ling. (2011. Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 129-136. doi:10.9767/bcrec.6.2.1213.129-136][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.1213.129-136 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/1213 ] | View in  |  

Applying life-cycle assessment to low carbon fuel standards-How allocation choices influence carbon intensity for renewable transportation fuels

International Nuclear Information System (INIS)

Kaufman, Andrew S.; Meier, Paul J.; Sinistore, Julie C.; Reinemann, Douglas J.

2010-01-01

The Energy Independence and Security Act (EISA) of 2007 requires life-cycle assessment (LCA) for quantifying greenhouse gas emissions (GHGs) from expanded U.S. biofuel production. To qualify under the Renewable Fuel Standard, cellulosic ethanol and new corn ethanol must demonstrate 60% and 20% lower emissions than petroleum fuels, respectively. A combined corn-grain and corn-stover ethanol system could potentially satisfy a major portion of renewable fuel production goals. This work examines multiple LCA allocation procedures for a hypothetical system producing ethanol from both corn grain and corn stover. Allocation choice is known to strongly influence GHG emission results for corn-ethanol. Stover-derived ethanol production further complicates allocation practices because additional products result from the same corn production system. This study measures the carbon intensity of ethanol fuels against EISA limits using multiple allocation approaches. Allocation decisions are shown to be paramount. Under varying approaches, carbon intensity for corn ethanol was 36-79% that of gasoline, while carbon intensity for stover-derived ethanol was -10% to 44% that of gasoline. Producing corn-stover ethanol dramatically reduced carbon intensity for corn-grain ethanol, because substantially more ethanol is produced with only minor increases in emissions. Regulatory considerations for applying LCA are discussed.

A survey of the Carbon Capture

International Nuclear Information System (INIS)

Jokrllova, J.; Cik, G.; Takacova, A.; Smolinska, M.

2014-01-01

The concentration of carbon dioxide, one of the most important representatives of greenhouse gases in the atmosphere continues to rise. Fossil fuels burned in thermal power plants currently represent 80% of total energy production around the world and are the largest point sources of CO 2 , accounting for approximately 40% of total CO 2 emissions. There are several options for reducing CO 2 emissions: reducing demand, improving production efficiency and carbon capture and storage (CCS, carbon capture and storage). Capture and storage of carbon dioxide is generally a three-step process: 1 st Capture and compression of combustion products, 2 nd transport (mostly pipeline) and 3 rd utilization (eg. production of urea, beverage industry, production of dry ice, etc.). Technologies for CO 2 capturing used in power plants burning fossil fuels can be divided into four groups, each of which requires a completely different approach to CO 2 capture.

Net ecosystem production and organic carbon balance of U.S. East Coast estuaries: A synthesis approach

Science.gov (United States)

Herrmann, Maria; Najjar, Raymond G.; Kemp, W. Michael; Alexander, Richard B.; Boyer, Elizabeth W.; Cai, Wei-Jun; Griffith, Peter C.; Kroeger, Kevin D.; McCallister, S. Leigh; Smith, Richard A.

2015-01-01

Net ecosystem production (NEP) and the overall organic carbon budget for the estuaries along the East Coast of the United States are estimated. We focus on the open estuarine waters, excluding the fringing wetlands. We developed empirical models relating NEP to loading ratios of dissolved inorganic nitrogen to total organic carbon, and carbon burial in the sediment to estuarine water residence time and total nitrogen input across the landward boundary. Output from a data-constrained water quality model was used to estimate inputs of total nitrogen and organic carbon to the estuaries across the landward boundary, including fluvial and tidal-wetland sources. Organic carbon export from the estuaries to the continental shelf was computed by difference, assuming steady state. Uncertainties in the budget were estimated by allowing uncertainties in the supporting model relations. Collectively, U.S. East Coast estuaries are net heterotrophic, with the area-integrated NEP of −1.5 (−2.8, −1.0) Tg C yr−1 (best estimate and 95% confidence interval) and area-normalized NEP of −3.2 (−6.1, −2.3) mol C m−2 yr−1. East Coast estuaries serve as a source of organic carbon to the shelf, exporting 3.4 (2.0, 4.3) Tg C yr−1 or 7.6 (4.4, 9.5) mol C m−2 yr−1. Organic carbon inputs from fluvial and tidal-wetland sources for the region are estimated at 5.4 (4.6, 6.5) Tg C yr−1 or 12 (10, 14) mol C m−2 yr−1 and carbon burial in the open estuarine waters at 0.50 (0.33, 0.78) Tg C yr−1 or 1.1 (0.73, 1.7) mol C m−2 yr−1. Our results highlight the importance of estuarine systems in the overall coastal budget of organic carbon, suggesting that in the aggregate, U.S. East Coast estuaries assimilate (via respiration and burial) ~40% of organic carbon inputs from fluvial and tidal-wetland sources and allow ~60% to be exported to the shelf.

Increased topsoil carbon stock across China's forests.

Science.gov (United States)

Yang, Yuanhe; Li, Pin; Ding, Jinzhi; Zhao, Xia; Ma, Wenhong; Ji, Chengjun; Fang, Jingyun

2014-08-01

Biomass carbon accumulation in forest ecosystems is a widespread phenomenon at both regional and global scales. However, as coupled carbon-climate models predicted, a positive feedback could be triggered if accelerated soil carbon decomposition offsets enhanced vegetation growth under a warming climate. It is thus crucial to reveal whether and how soil carbon stock in forest ecosystems has changed over recent decades. However, large-scale changes in soil carbon stock across forest ecosystems have not yet been carefully examined at both regional and global scales, which have been widely perceived as a big bottleneck in untangling carbon-climate feedback. Using newly developed database and sophisticated data mining approach, here we evaluated temporal changes in topsoil carbon stock across major forest ecosystem in China and analysed potential drivers in soil carbon dynamics over broad geographical scale. Our results indicated that topsoil carbon stock increased significantly within all of five major forest types during the period of 1980s-2000s, with an overall rate of 20.0 g C m(-2) yr(-1) (95% confidence interval, 14.1-25.5). The magnitude of soil carbon accumulation across coniferous forests and coniferous/broadleaved mixed forests exhibited meaningful increases with both mean annual temperature and precipitation. Moreover, soil carbon dynamics across these forest ecosystems were positively associated with clay content, with a larger amount of SOC accumulation occurring in fine-textured soils. In contrast, changes in soil carbon stock across broadleaved forests were insensitive to either climatic or edaphic variables. Overall, these results suggest that soil carbon accumulation does not counteract vegetation carbon sequestration across China's forest ecosystems. The combination of soil carbon accumulation and vegetation carbon sequestration triggers a negative feedback to climate warming, rather than a positive feedback predicted by coupled carbon-climate models

Carbon aerogels by pyrolysis of TEMPO-oxidized cellulose

Science.gov (United States)

Zhang, Sizhao; Feng, Jian; Feng, Junzong; Jiang, Yonggang; Ding, Feng

2018-05-01

Although carbon aerogels derived from naturally occurring materials have been developed extensively, a reasonable synthetic approach using cellulose-resource remains unclear. Here, we report a strategy to prepare carbon aerogels originated from cellulose position-selectively oxidized by TEMPO-oxidized process. Contrary to non-TEMPO-oxidized cellulose-derived carbon aerogels (NCCA) with relative loose structure, TEMPO-oxidized cellulose-derived carbon aerogels (TCCA) with tight fibrillar-continuous network are monitored, suggesting the importance of TEMPO-oxidized modification towards creating the architecture of subsequently produced carbon aerogels. TCCA endows a higher BET area despite owning slightly dense bulk density comparing with that of NCCA. The structural texture of TCCA could be maintained in a way in comparison to TEMPO-oxidized cellulose-derived aerogel, due to the integration and aggregation effect by losing the electric double layer repulsion via ionization of the surface carboxyl groups. FTIR and XPS analyses signify the evidence of non-functionalized carbon-skeleton network formation in terms of TCCA. Further, the mechanism concerning the creation of carbon aerogels is also established. These findings not only provide new insights into the production of carbon aerogels but also open up a new opportunity in the field of functional carbon materials.

Groundwater circulation in deep carbonate regions

Science.gov (United States)

Szönyi-Mádl, Judit; Tóth, Ádám

2016-04-01

The operation of the subsurface part of the hydrologic cycle is hardly understood on basin scale due to the limitation in validated knowledge. Therefore the water balance approach is used with simplified numerical approaches during solving water related problems. The understanding of hierarchical nature of gravity-driven groundwater flow in near-surface and other driving forces in the deeper part of the lithosphere are often neglected. In this context thick and deep carbonate regions are especially less understood because the applicability of the gravity-driven regional groundwater flow (GDRGF) concept for such ranges formerly was debated. This is because karst studies are focused rather on the understanding of heterogeneity of karst systems. In contrary, this study found, on the basis of REV concept, that at regional scale not the local permeability values but its regional distribution is decisive. Firstly, according to the hydraulic diffusivity values it was stated that hydraulic connectivity is more effective in basinal carbonates compared to siliciclastics. Consequently, the efficient hydraulic responses for hydraulic head changes (due to water production or injection) in a carbonate system can give an indirect clue regarding hydraulic connectivity of the system rather than understanding the detailed permeability distribution. The concerns of the applicability of the GDRGF concept, therefore could be resolved. Subsequently, the concept of GDRGF can be used as a working hypothesis for understanding basinal hydraulics and geologic agency of flowing groundwater in thick carbonate ranges (Mádl-Szonyi and Tóth 2015). The hydrogeologically complex thick carbonate system of the Transdanubian Range (TR) Hungary was used as a study area to reveal the role of GDRGF at basin scale. Water level changes in the system, due to long-term mine dewatering exemplify the hydraulic continuity and compartmentalization of the system. Clustering of spring data, numerical flow and

An approach to optimize economics in a west Texas CO2 flood

International Nuclear Information System (INIS)

Pariani, G.J.; McColloch, K.A.; Warden, S.L.; Edens, D.R.

1992-01-01

Enhanced oil recovery projects, most notably CO 2 floods, are the next generation of recovery methods in the more mature West Texas waterfloods. The cost of installing and operating a CO 2 flood can be extremely high. In this paper, the authors will discuss the methods the authors used to make several active CO 2 floods more profitable by reducing operating costs and deferring investments. This paper reports that the author's goals in studying several active West Texas CO 2 floods were to determine the optimum near term cash flow, overall project economics (rate of return, present worth etc.) and oil recoveries. Using a reservoir simulator, various CO 2 flood designs were developed by altering specific operating parameters including the half-cycle slug size, gas-water ratio (GWR) injection schemes and total CO 2 slug sizes. The resulting injection and production rates were then entered into an economic simulator to determine the most economic set of operating conditions

Baseline Map of Carbon Emissions from Deforestation in Tropical Regions

Science.gov (United States)

Harris, Nancy L.; Brown, Sandra; Hagen, Stephen C.; Saatchi, Sassan S.; Petrova, Silvia; Salas, William; Hansen, Matthew C.; Potapov, Peter V.; Lotsch, Alexander

2012-06-01

Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss and a map of forest carbon stocks to estimate gross carbon emissions across tropical regions between 2000 and 2005 as 0.81 petagram of carbon per year, with a 90% prediction interval of 0.57 to 1.22 petagrams of carbon per year. This estimate is 25 to 50% of recently published estimates. By systematically matching areas of forest loss with their carbon stocks before clearing, these results serve as a more accurate benchmark for monitoring global progress on reducing emissions from deforestation.

Baseline map of carbon emissions from deforestation in tropical regions.

Science.gov (United States)

Harris, Nancy L; Brown, Sandra; Hagen, Stephen C; Saatchi, Sassan S; Petrova, Silvia; Salas, William; Hansen, Matthew C; Potapov, Peter V; Lotsch, Alexander

2012-06-22

Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss and a map of forest carbon stocks to estimate gross carbon emissions across tropical regions between 2000 and 2005 as 0.81 petagram of carbon per year, with a 90% prediction interval of 0.57 to 1.22 petagrams of carbon per year. This estimate is 25 to 50% of recently published estimates. By systematically matching areas of forest loss with their carbon stocks before clearing, these results serve as a more accurate benchmark for monitoring global progress on reducing emissions from deforestation.

Three-Dimensional Water and Carbon Cycle Modeling at High Spatial-Temporal Resolutions

Science.gov (United States)

Liao, C.; Zhuang, Q.

2017-12-01

Terrestrial ecosystems in cryosphere are very sensitive to the global climate change due to the presence of snow covers, mountain glaciers and permafrost, especially when the increase in near surface air temperature is almost twice as large as the global average. However, few studies have investigated the water and carbon cycle dynamics using process-based hydrological and biogeochemistry modeling approach. In this study, we used three-dimensional modeling approach at high spatial-temporal resolutions to investigate the water and carbon cycle dynamics for the Tanana Flats Basin in interior Alaska with emphases on dissolved organic carbon (DOC) dynamics. The results have shown that: (1) lateral flow plays an important role in water and carbon cycle, especially in dissolved organic carbon (DOC) dynamics. (2) approximately 2.0 × 104 kg C yr-1 DOC is exported to the hydrological networks and it compromises 1% and 0.01% of total annual gross primary production (GPP) and total organic carbon stored in soil, respectively. This study has established an operational and flexible framework to investigate and predict the water and carbon cycle dynamics under the changing climate.

The "Carbon Data Explorer": Web-Based Space-Time Visualization of Modeled Carbon Fluxes

Science.gov (United States)

Billmire, M.; Endsley, K. A.

2014-12-01

The visualization of and scientific "sense-making" from large datasets varying in both space and time is a challenge; one that is still being addressed in a number of different fields. The approaches taken thus far are often specific to a given academic field due to the unique questions that arise in different disciplines, however, basic approaches such as geographic maps and time series plots are still widely useful. The proliferation of model estimates of increasing size and resolution further complicates what ought to be a simple workflow: Model some geophysical phenomen(on), obtain results and measure uncertainty, organize and display the data, make comparisons across trials, and share findings. A new tool is in development that is intended to help scientists with the latter parts of that workflow. The tentatively-titled "Carbon Data Explorer" (http://spatial.mtri.org/flux-client/) enables users to access carbon science and related spatio-temporal science datasets over the web. All that is required to access multiple interactive visualizations of carbon science datasets is a compatible web browser and an internet connection. While the application targets atmospheric and climate science datasets, particularly spatio-temporal model estimates of carbon products, the software architecture takes an agnostic approach to the data to be visualized. Any atmospheric, biophysical, or geophysical quanity that varies in space and time, including one or more measures of uncertainty, can be visualized within the application. Within the web application, users have seamless control over a flexible and consistent symbology for map-based visualizations and plots. Where time series data are represented by one or more data "frames" (e.g. a map), users can animate the data. In the "coordinated view," users can make direct comparisons between different frames and different models or model runs, facilitating intermodal comparisons and assessments of spatio-temporal variability. Map

A new approach to produce amino-carbon nanotubes as plasmid transfection vector by [2 + 1] cycloaddition of nitrenes

International Nuclear Information System (INIS)

Jiang Yongjian; Jin Chen; Yang Feng; Yu Xianjun; Wang Guojian; Cheng Si; Di, Yang; Li, Ji; Fu, Deliang; N, Quanxing

2011-01-01

Amino-carbon nanotubes (amino-CNTs) can conjugate with the DNA by electrostatic interactions and shuttle the DNA to the cell cytoplasm or even the nucleus. Here we report a new approach to produce amino-CNTs by cycloaddition of nitrenes. Fourier transform infrared spectroscopy was used to verify the success of the functionalization, and the functionalization degree was calculated by thermal gravity analysis. Transmission electron microscope (TEM) was used to observe the solubility of the CNTs and the interactions of the amino-CNTs with the plasmids. Cell ultrathin sections were made and observed under the TEM to confirm the amino-CNTs enter the cells. Transfection experiments ultimately verify the amino-CNTs produced through cycloadditions of nitrenes can serve as plasmid vector.

Latest Permian carbonate carbon isotope variability traces heterogeneous organic carbon accumulation and authigenic carbonate formation