共查询到20条相似文献,搜索用时 23 毫秒
1.
Jürgen Kern Hans Jürgen Hellebrand Volkhard Scholz Bernd Linke 《Renewable & Sustainable Energy Reviews》2010,14(5):1453-1460
This study was designed to consider all nitrogen fertilizer-related effects on crop production and emission of greenhouse gases on loamy sandy soils in Germany over a period of nine years (1999–2007). In order to set up a CO2 balance for the production of energy crops, different nitrogen pathways were investigated, such as direct N2O emissions from the soil and indirect emissions related to NO3 leaching and fertilizer production. Fluxes of N2O were measured in an experimental field using closed chambers. Poplar (Populus maximowiczii × P. nigra) and rye (Secale cereale L.) as one perennial and one annual crop were fertilized at rates of 0 kg N ha?1 yr?1, 75 kg N ha?1 yr?1 and 150 kg N ha?1 yr?1. The mean N2O emissions from the soil ranged between 0.5 kg N ha?1 yr?1 and 2.5 kg N ha?1 yr?1 depending on fertilization rate, crop variety and year. The CO2 fixed in the biomass of energy crops is reduced by up to 16% if direct N2O emissions from soil and indirect N2O emissions from NO3 leaching and fertilizer production are included. Taking into account the main greenhouse gas emissions, which derive from the production and the use of N fertilizer, the growth of poplar and rye may replace the global warming potential of fossil fuels by up to 17.7 t CO2 ha?1 yr?1 and 12.1 t CO2 ha?1 yr?1, respectively. 相似文献
2.
The phenomena of natural convection in an inclined square enclosure heated via corner heater have been studied numerically. Finite difference method is used for solving momentum and energy equations in the form of stream function–vorticity. One wall of the enclosure is isothermal but its temperature is colder than that of heaters while the remaining walls are adiabatic. The numerical procedure adopted in this analysis yields consistent performance over a wide range of parameters; Rayleigh number, Ra (103 ? Ra ? 106); Prandtl number, Pr (0.07 ? Pr ? 70); dimensionless lengths of heater in x and y directions (0.25 ? hx ? 0.75, 0.25 ? hy ? 0.75); and inclination angle, ? (0° ? ? ? 270°). It is observed that heat transfer is maximum or minimum depending on the inclination angle and depending on the length of the corner heaters. The effect of Prandtl number on mean Nusselt number is more significant for Pr < 1. 相似文献
3.
《Biomass & bioenergy》2005,28(5):475-489
Nonrenewable energy consumption and greenhouse gas (GHG) emissions associated with ethanol (a liquid fuel) derived from corn grain produced in selected counties in Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin are presented. Corn is cultivated under no-tillage practice (without plowing). The system boundaries include corn production, ethanol production, and the end use of ethanol as a fuel in a midsize passenger car. The environmental burdens in multi-output biorefinery processes (e.g., corn dry milling and wet milling) are allocated to the ethanol product and its various coproducts by the system expansion allocation approach.The nonrenewable energy requirement for producing 1 kg of ethanol is approximately 13.4–21.5 MJ (based on lower heating value), depending on corn milling technologies employed. Thus, the net energy value of ethanol is positive; the energy consumed in ethanol production is less than the energy content of the ethanol (26.8 MJ kg−1).In the GHG emissions analysis, nitrous oxide (N2O) emissions from soil and soil organic carbon levels under corn cultivation in each county are estimated by the DAYCENT model. Carbon sequestration rates range from 377 to 681 kg C ha−1 year−1 and N2O emissions from soil are 0.5–2.8 kg N ha−1 year−1 under no-till conditions. The GHG emissions assigned to 1 kg of ethanol are 260–922 g CO2 eq. under no-tillage. Using ethanol (E85) fuel in a midsize passenger vehicle can reduce GHG emissions by 41–61% km−1 driven, compared to gasoline-fueled vehicles. Using ethanol as a vehicle fuel, therefore, has the potential to reduce nonrenewable energy consumption and GHG emissions. 相似文献
4.
David M. Burner Thomas L. Tew Jonathan J. Harvey David P. Belesky 《Biomass & bioenergy》2009,33(4):610-619
The partitioning and quality of aboveground biomass have important ramifications for crop management and biomass conversion. In preliminary studies, Saccharum sp. × Miscanthus sp. hybrids exhibited stubble cold tolerance in west-central Arkansas, unlike Saccharum sp. × Saccharum spontaneum hybrids. The objective was to examine foliar and stem quality of the C4 grasses Miscanthus sinensis (‘Gracillimus’), Miscanthus x giganteus (Q42641, proprietary), Panicum virgatum (‘Alamo’), and two F1 hybrids of Saccharum sp. × Miscanthus sp. (US84-1028 and US84-1058) in a field study during 2004 (plant cane) and 2005 (first stubble) near Booneville, AR. Switchgrass produced more stems m?2 than the other entries both years, and there was little difference in stem number among other entries. Clone US84-1028 yielded more dry mass m?2 than other entries in plant cane, while switchgrass, US84-1028, and M. x giganteus did not differ in first stubble. Clone US84-1028 also had more stem dry mass and leaf dry mass than other entries both yr. Tissue N concentrations were low for these entries, but leaves contained about twice the N of stems (≤15.2 and 7.8 g kg?1, respectively). Leaves represented as much as one-third of total biomass, and had large cellulose (≤482 g kg?1) and lignin (167 g kg?1) concentrations. The competitively high biomass yield of this small sample of sugarcane alleles should encourage the expansion of the crop beyond its current production regions. Sugarcane and M. x giganteus should be examined in higher-input temperate systems because of their bioenergy potential. 相似文献
5.
《Biomass & bioenergy》2006,30(7):638-647
The use of firewood for domestic heating has the potential to reduce fossil-fuel use and associated CO2 emissions. The level of possible reductions depends upon the extent to which firewood off-sets the use of fossil fuels, the efficiency with which wood is burnt, and use of fossil fuels for collection and transport of firewood. Plantations grown for firewood also have a cost of emissions associated with their establishment. Applying the FullCAM model and additional calculations, these factors were examined for various management scenarios under three contrasting firewood production systems (native woodland, sustainably managed native forest, and newly established plantations) in low-medium rainfall (600–800 mm) regions of south-eastern Australia. Estimates of carbon dioxide emissions per unit of heat energy produced for all scenarios were lower than for non-renewable energy sources (which generally emit about 0.3–1.0 kg CO2 kWh−1). Amongst the scenarios, emissions were greatest when wood was periodically collected from dead wood in woodlands (0.11 kg CO2 kWh−1), and was much lower when obtained from harvest residues and dead wood in native forests (<0.03 kg CO2 kWh−1). When wood was obtained from plantations established on previously cleared agricultural land, use of firewood led to carbon sequestration equivalent to −0.06 kg CO2 kWh−1 for firewood obtained from a coppiced plantation, and −0.17 kg CO2 kWh−1 for firewood collected from thinnings, slash and other residue in a plantation grown for sawlog production. An uncertainty analysis, where inputs and assumptions were varied in relation to a plausible range of management practices, identified the most important influencing factors and an expected range in predicted net amount of CO2 emitted per unit of heat energy produced from burning firewood. 相似文献
6.
Previous studies indicate biomass and grain production for energy purposes as potential utilizations of the three Cynara cardunculus botanical varieties (globe artichoke, cultivated cardoon, and wild cardoon). In this work, the results of C. cardunculus biomass and grain yield under Sicilian (south Italy) low input conditions are shown. Over a 3 year period on the plain of Catania (South Italy) six genotypes of C. cardunculus, including 1 cultivated cardoon cultivar, 1 globe artichoke line, 1 wild cardoon ecotype, 3 F1 progenies: “globe artichoke × wild cardoon”, “globe artichoke × cultivated cardoon” and “cultivated cardoon × wild cardoon”, were evaluated for lignocellulosic biomass production, energy yield and grain yield. On a 3 year average, the dry aboveground biomass and grain yield resulted, respectively, about 2000 g plant?1 and 100 g plant?1 in “globe artichoke × wild cardoon”, 1720 and 126 g plant?1 in cultivated cardoon, 1570 and 90 g plant?1 in “globe artichoke × cultivated cardoon”, 1480 and 109 g plant?1 in “cultivated cardoon × wild cardoon”, 1116 and 75 g plant?1 in wild cardoon and 990 and 60 g plant?1 in globe artichoke. The results showed that genotypes deriving from the cross of globe artichoke with cultivated and wild cardoon improved the performance both of globe artichoke and wild cardoon separately. It is reasonable to expect further improvements for biomass and grain yield in C. cardunculus in the future by breeding work. 相似文献
7.
Abdalla AlAmiri Khalil Khanafer Ioan Pop 《International Journal of Heat and Mass Transfer》2009,52(15-16):3818-3828
The present investigation addressed buoyancy-induced heat transfer in a partially divided square enclosure. The transport equations were solved using the finite element formulation based on the Galerkin method of weighted residuals. The validity of the numerical code used was ascertained by comparing our results with previously published results. Results were obtained in terms of streamlines, isotherms, and Nusselt number for various geometrical parameters specifying the height, width and position of the heater. The effect of Rayleigh number in the range of 104 ? Ra ? 5 × 107 was highlighted in the proposed work. The results revealed that all the parameters related to the geometrical dimensions of the heater were significant on the flow field, isotherms, and heat transfer. The examined dimensionless geometric dimensions employed along with their respective ranges were: heater width (0.005 ? W ? 0.5), heater height (0.005 ? H ? 0.5), and heater location (0 ? D ? 0.5). The investigation revealed that increased heater height, width, and location has enhanced the heat transfer due to increasing the surface area of the heater. 相似文献
8.
Elif Büyük Öğüt 《International Journal of Thermal Sciences》2009,48(11):2063-2073
This study investigates natural convection heat transfer of water-based nanofluids in an inclined square enclosure where the left vertical side is heated with a constant heat flux, the right side is cooled, and the other sides are kept adiabatic. The governing equations are solved using polynomial differential quadrature (PDQ) method. Calculations were performed for inclination angles from 0° to 90°, solid volume fractions ranging from 0% to 20%, constant heat flux heaters of lengths 0.25, 0.50 and 1.0, and a Rayleigh number varying from 104 to 106. The ratio of the nanolayer thickness to the original particle radius is kept at a constant value of 0.1. The heat source is placed at the center of the left wall. Five types of nanoparticles are taken into consideration: Cu, Ag, CuO, Al2O3, and TiO2. The results show that the average heat transfer rate increases significantly as particle volume fraction and Rayleigh number increase. The results also show that the length of the heater is also an important parameter affecting the flow and temperature fields. The average heat transfer decreases with an increase in the length of the heater. As the heater length is increased, the average heat transfer rate starts to decrease for a smaller inclination angle (it starts to decrease with inclination at 90° for ? = 0.25, 60° for ? = 0.50, 45° for ? = 1.0, respectively). 相似文献
9.
《Biomass & bioenergy》2006,30(7):673-683
This paper is concerned with development of a pulverised fuel stove with improved conversion efficiency and minimal emissions at near constant power level without the use of external power. The design originates from a cylindrical sawdust stove with a central porthole being lit from the bottom. Such a stove will have a flame in port with enhanced sooting tendency. For similar configuration, stable premixed combustion behaviour of the combustible gases from the port of the fuel block (known as the gasification mode) has been achieved by use of air supply through a thin slot at the bottom, for at least 30 min of stove operation. In order to ensure stable combustion of the gases at exit, a metal device is used. In an attempt to extend gasification duration, studies are conducted in single port configuration having air entry from the bottom with a horizontal baffle to control the flow rate. This configuration worked in gasification mode for about 20 min but there have been problems of flame extinction. To overcome these drawbacks multi-port design with vertical air entry is employed with success.The stove has exhibited conversion efficiency in excess of 37% due to well focused nature of flame at exit. CO emission factors are about 12 g (kg fuel)−1, a performance superior to conventional biomass stoves (∼45 g kg−1). NOx emission factors are about 1 g kg−1 fuel which falls in the range of reported data for NOx. Studies with different pulverised leafy fuels have indicated these fuels have lower volatile release rates and therefore exhibit lower power level operation for a given port configuration compared to sawdust fuel. 相似文献
10.
C.T. Wright J.E. O’Brien R.E. Spall 《International Journal of Heat and Mass Transfer》2008,51(5-6):1071-1084
A critical heat flux (CHF) study of the vertical up-flow of water through multiple thin rectangular channels was conducted. Pressures varied from 89.8 to 115 kPa, inlet temperatures from 291 to 306 K, and mass fluxes from 9.5 to 39 kg m?2 s?1. Electrical resistance heaters embedded in aluminum provided a uniform heat flux. A more universal and robust CHF correlation based on the geometry of the Advanced Test Reactor at Idaho National Laboratory was developed. This new CHF correlation predicts 126 data points from this and three previous studies within an error of ±8.5% with a 95% confidence. 相似文献
11.
Vitaliy Kryvoruchko Andrea Machmüller Vitomir Bodiroza Barbara Amon Thomas Amon 《Biomass & bioenergy》2009,33(4):620-627
Anaerobic digestion (AD) is a promising option for the environmentally friendly recycling of agricultural by-products. However, overloading of the digester with sugar, starch or protein might cause inhibition of the anaerobic processes. The aim of the present project was to investigate the AD of sugar beet, starch potato by-products and effect of pre-treatment by steam on methane yield of potatoes pulp. The investigated by-products have been: sugar beet pulp silage (SBP), sugar beet tail silage (SBT), potato pulp (PP), potato peel pulp (PPP) and potato fruit water (PFW). All by-products were digested in 1 l eudiometer-batch digesters at 37.5 °C during 28–38 days. The specific methane yields of SBP and SBT were 430 and 481 lN kg?1 volatile solids (VS), respectively. The specific methane yields of PP, PPP and PFW were 332, 377 and 323 lN (kg VS)?1. A steam pre-treatment significantly increased the specific methane yield of PP up to 373 lN (kg VS)?1. 相似文献
12.
Sibel Dikmen Hasan Aslanbay Erdal Dikmen Osman Şahin 《Journal of power sources》2010,195(9):2488-2495
The structure, the thermal expansion coefficient, electrical conductivities of Ce0.8Gd0.2?xMxO2?δ (for M: Bi, x = 0–0.1, and for M: Sm, La, and Nd, x = 0.02) solid solutions, prepared for the first time hydrothermally, are investigated. The uniformly small particle size (28–59 nm) of the materials allows sintering of the samples into highly dense ceramic pellets at 1300–1400 °C. The maximum conductivity, σ700 °C around 4.46 × 10?2 S cm?1 with Ea = 0.52 eV, is found at x = 0.1 for Bi-co-doping. Among various metal-co-dopings, for x = 0.02, the maximum conductivity, σ700 °C around 2.88 × 10?2 S cm?1 with Ea = 0.67 eV, is found for Sm-co-doping. The electrolytic domain boundary (EDB) of Ce0.8Gd0.1Bi0.1O2?δ is found to be 1.2 × 10?19 atm, which is relatively lower than that of the singly doped samples. The thermal expansion coefficients, determined from high-temperature X-ray data are 11.6 × 10?6 K?1 for the CeO2, 12.1 × 10?6 K?1 for Ce0.8Gd0.2O2?δ, and increase with co-doping to 14.2 × 10?6 K?1 for Ce0.8Gd0.18Bi0.02O2?δ. The maximum power densities for the single cell based on the codoped samples are higher than that of the singly doped sample. These results suggest that co-doping can further improve the electrical performance of ceria-based electrolytes. 相似文献
13.
The use of rubber-seed shell as a raw material for the production of activated carbon with physical activation was investigated. The produced activated carbons were characterized by Nitrogen adsorption isotherms, Scanning electron microscope, Thermo-gravimetric and Differential scanning calorimetric in order to understand the rubber-seed shell activated carbon. The results showed that rubber-seed shell is a good precursor for activated carbon. The optimal activation condition is: temperature 880 °C, steam flow 6 kg h?1, residence time 60 min. Characteristics of activated carbon with a high yield (30.5%) are: specific surface area (SBET) 948 m2 g?1, total volume 0.988 m3 kg?1, iodine number of adsorbent (qiodine) 1.326 g g?1, amount of methylene blue adsorption of adsorbent (qmb) 265 mg g?1, hardness 94.7%. It is demonstrated that rubber-seed shell is an attractive source of raw material for producing high capacity activated carbon by physical activation with steam. 相似文献
14.
The impact of anaerobic digestion (AD) technology on mitigating greenhouse gas (GHG) emissions from manure management on typical dairy, sow and pig farms in Finland was compared. Firstly, the total annual GHG emissions from the farms were calculated using IPCC guidelines for a similar slurry type manure management system. Secondly, laboratory-scale experiments were conducted to estimate methane (CH4) potentials and process parameters for semi-continuous digestion of manures. Finally, the obtained experimental data were used to evaluate the potential renewable energy production and subsequently, the possible GHG emissions that could be avoided through adoption of AD technology on the studied farms. Results showed that enteric fermentation (CH4) and manure management (CH4 and N2O) accounted for 231.3, 32.3 and 18.3 Mg of CO2 eq. yr?1 on dairy, sow and pig farms, respectively. With the existing farm data and experimental methane yields, an estimated renewable energy of 115.2, 36.3 and 79.5 MWh of heat yr?1 and 62.8, 21.8 and 47.7 MWh of electricity yr?1 could be generated in a CHP plant on these farms respectively. The total GHG emissions that could be offset on the studied dairy cow, sow and pig farms were 177, 87.7 and 125.6 Mg of CO2 eq. yr?1, respectively. The impact of AD technology on mitigating GHG emissions was mainly through replaced fossil fuel consumption followed by reduced emissions due to reduced fertilizer use and production, and from manure management. 相似文献
15.
Lihong Shen David M. Bagley Steven N. Liss 《International Journal of Hydrogen Energy》2009,34(9):3689-3696
The influence of organic loading rates (OLRs) on the performance of fermentative hydrogen-producing bioreactors operating in continuous stirred tank reactor (CSTR) and membrane bioreactor (MBR) modes was examined. Five OLRs were examined, ranging from 4.0 to 30 g COD L?1 d?1, with influent glucose concentrations ranging from 1.3 to 10 g COD L?1. At OLRs up to 13 g COD L?1 d?1, all influent glucose was utilized and the H2 yield was not significantly influenced by OLR, although the yield in the CSTR mode was significantly higher than that in the MBR mode, 1.25 versus 0.97 mol H2 (mol Gluc. Conv.)?1, respectively. At an OLR of 30 g COD L?1 d?1, both reactor modes were overloaded with respect to glucose utilization and also had significantly higher H2 yields of 1.77 and 1.49 mol H2 (mol Gluc. Conv.)?1 for the CSTR and MBR modes, respectively, versus the underloaded operation. At the intermediate OLR of 22 g COD L?1 d?1, the H2 yield was maximized at 1.78 mol H2 (mol Gluc. Conv.)?1 for both the CSTR and MBR operation. Overall H2 production was 50% higher in the MBR mode, 0.78 versus 0.51 moles d?1, because the CSTR mode was overloaded with respect to glucose utilization at this OLR. These results suggest that an optimum OLR that maximizes H2 yield and H2 production may be near the OLR that causes overload with respect to substrate utilization. Additionally, while the CSTR mode is easier to operate and provides higher H2 yields at underloaded and overloaded OLRs, the MBR mode may be preferable when operating near the optimum OLR. 相似文献
16.
《Journal of power sources》2001,92(1-2):228-233
Polyamides (DTA-I, DTA-II, and DTA-III) containing cyclic disulfide structure were prepared by condensation between 1,2-dithiane-3,6-dicarboxylic acid (DTA) and alkyl diamine, NH2–(CH2)n–NH2 (DTA-I; n=4, DTA-II; n=6, DTA-III; n=8) and their application to positive active material for lithium secondary batteries was investigated. Cyclic voltammetry (CV) measurements under slow sweep rate (0.5 mV s−1) with a carbon paste electrode containing the polyamide (DTA-I, DTA-II, or DTA-III) were performed. The results indicated that the polyamides were electroactive in the organic electrolyte solution (propylene carbonate (PC)-1,2-dimethoxyethane (DME), 1:1 by volume containing lithium salt, such as LiClO4). The responses based on the redox of the disulfide bonds in the polyamide were observed.Test cells, Li/PC-DME (1:1. by volume) with 1 mol dm−3 LiClO4/the polyamide cathode, were constructed and their performance was tested under constant current charge/discharge condition. The average capacity of the test cells with the DTA-III cathode was 64.3 Ah kg−1 of cathode (135 Wh kg−1 of cathode, capacity (Ah kg−1) of the cathode×average cell voltage (2.10 V)). Performance of the cell with linear polyamide containing disulfide bond (–CO–(CH2)2–S–S–(CH2)2–CONH–(CH2)8–NH–, GTA-III) was also investigated and the average capacity was 56.8 Ah kg−1 of cathode (100 Wh kg−1 of cathode, capacity (Ah kg−1) of the cathode×average cell voltage (1.76 V)). Cycle efficiency of the test cell with the DTA-III cathode was higher than that with the GTA-III cathode. 相似文献
17.
Hakan F. Öztop M.M. Rahman A. Ahsan M. Hasanuzzaman R. Saidur Khaled Al-Salem N.A. Rahim 《International Journal of Heat and Mass Transfer》2012,55(7-8):1844-1854
A computational study of the thermal and dynamical behavior of fluid in an enclosure with two isothermal semi-circular heaters is presented. The top wall and the flat surfaces on bottom wall are adiabatic while the vertical walls are kept at lower temperature than the semi-circular heaters. The radius of curvature of the semi-circular surfaces is chosen as one tenth of the cavity wall length. The governing equations are solved by the Galerkin weighted residual finite element method. The effect of magnetic field on the flow is another important parameter in this study. Numerical simulations were performed for several values of Rayleigh number (103 ? Ra ? 106), Hartmann number (0 ? Ha ? 50) and the distance between two semi-circular heaters (0.2 ? D ? 0.8). In all cases the Prandtl number is taken as 7. It is found that the distance between the semi-circular heaters is the most important parameter affecting the heat and fluid flow fields. In addition, Hartmann number was found to have an adverse affect on heat transfer. 相似文献
18.
Jesús Cerezo Roberto Best Mahmoud Bourouis Alberto Coronas 《International Journal of Heat and Mass Transfer》2010,53(17-18):3379-3386
A mathematical model for ammonia–water bubble absorbers was developed and compared with experimental data using a plate heat exchanger. The analysis was performed carrying out a sensitive study of selected operation parameters on the absorber thermal load and mass absorption flux. Regarding the experimental data, the values obtained for the solution heat transfer were in the range 0.51–1.21 kW m?2 K?1 and those of the mass absorption flux in the range 2.5–5.0 × 10?3 kg m?2 s?1. The comparison between experimental and simulation results was acceptable being the maximum difference of 11.1% and 28.4% for the absorber thermal load and the mass absorption flux, respectively. 相似文献
19.
Four-week-old seedlings of Grindelia camporum Greene were planted in a mild calcareous alluvial soil collected from Mahibullapur, in Lucknow district (26° 30′ N latitude–80° 30′ E longitude) in pot culture. The soil, rated sulphur deficient on the basis of available soil sulphur, was fertilized with calcium sulphate to provide sulphur at the rate of 10, 25, 50, and 100 mg kg?1 soil. Observations on growth (height, branching, leaf area) were recorded periodically. Plants were harvested 26 weeks after transplantation (wat) and measured for biomass and biocrude yields. After harvest, the pot soil was measured for available sulphur using three extractants: 0.15% CaCl2, 0.5 M NaHCO3, pH 8.5, and Morgan's extract.The native soil (control) is rated deficient in available sulphur; and availability of sulphur increased with increasing levels of sulphur fertilization. The vegetative growth of plants reached the maximum in response to sulphur amendment at the rate of 50 mg kg?1 soil 14 weeks after transplantation to pots. At the time of harvest, 26 weeks after transplantation, plants showed best growth and maximum number of capitula and weight, in response to sulphur amendment at the rate of 100 mg kg?1 soil. Thus, G. camporum showed a higher requirement of sulphur during the reproductive phase than for its vegetative growth and biomass yield. Maximum biocrude yield, both the total and ethyl acetate and methanol extractable fractions, was also obtained when sulphur was applied at the rate of 100 mg kg?1 soil. 相似文献
20.
Matthew Langholtz Douglas R. Carter Donald L. Rockwood Janaki R.R. Alavalapati 《Biomass & bioenergy》2009,33(5):785-792
Fast growing, short-rotation tree crops provide unique opportunities to sequester carbon on phosphate-mined lands in central Florida and, if used as a biofuel, can reduce CO2 emissions associated with electricity generation. Base case land expectation values (LEVs) of phosphate-mined land under Eucalyptus amplifolia (EA) forestry range from 762 to 6507 $ ha?1 assuming real discount rates of 10% and 4%, respectively. Assuming 5 $ Mg?1 C, these LEVs increase from 3% to 24% with incentives for in situ carbon sequestration benefits, or 21% to 73% given in situ carbon sequestration with additional incentives for reducing CO2 emissions through the use of EA as an energy feedstock. Potential benefits from below-ground C sequestration and mine land reclamation are estimated to be worth an additional 5642–11,056 $ ha?1. 相似文献