Biofuel Yield Research Articles

Refining lipid for aviation biofuel at the molecular level

For improving aviation biofuel in quantity and quality, main precursor compounds have been investigated on the hydrotreating mechanism, including triglycerides by lipid extraction, fatty acid methyl/ethyl esters by transesterification, and fatty acids by hydrothermal liquefaction. Hydrotreating tests have been conducted on the effects of temperature, pressure, catalyst loading, and reaction time at molecular level. Fatty acid methyl/ethyl esters are the most desirable hydrotreating compounds for their highest biofuel yield and mildest upgrading conditions(≥290 °C, ≥10% catalyst loading). At the proper conditions of 290 °C and 30% catalyst loading, methyl stearate can yield 61.6% biofuel with 100% selectivity to alkanes. Fatty acids are the most difficult compounds to upgrade and should be hydrotreated above 310 °C and at least 30% catalyst loading, otherwise there are unconverted fatty acids, fatty aldehydes and fatty alcohols in the products. C30+ heavy esters are commonly found in the undesirable products and suppose to be derived from esterification of fatty acids and fatty alcohols under low temperature. Enhancing carbon number and unsaturation of the precursors promote the generation of olefins and oxygenates.

Fermentation of D-xylose to Ethanol by Saccharomyces cerevisiae CAT-1 Recombinant Strains.

Ethanol production by the D-xylose fermentation of lignocellulosic biomass would augment environmental sustainability by increasing the yield of biofuel obtained per cultivated area. A set of recombinant strains derived from the industrial strain Saccharomyces cerevisiae CAT-1 was developed for this purpose. First, two recombinant strains were obtained by the chromosomal insertion of genes involved in the assimilation and transport of D-xylose (Gal2-N376F). Strain CAT-1-XRT was developed with heterologous genes for D-xylose metabolism from the oxo-reductive pathway of Scheffersomyces stipitis (XYL1-K270R, XYL2); and strain CAT-1-XIT, with D-xylose isomerase (xylA gene, XI) from Streptomyces coelicolor. Moreover, both recombinant strains contained extra copies of homologous genes for xylulose kinase (XK) and transaldolase (TAL1). Furthermore, plasmid (pRS42K::XI) was constructed with xylA from Piromyces sp. transferred to CAT-1, CAT-1-XRT, and CAT-1-XIT, followed by an evolution protocol. After 10 subcultures, CAT-1-XIT (pRS42K::XI) consumed 74% of D-xylose, producing 12.6 g/L ethanol (0.31 g ethanol/g D-xylose). The results of this study show that CAT-1-XIT (pRS42K::XI) is a promising recombinant strain for the efficient utilization of D-xylose to produce ethanol from lignocellulosic materials.

Combined Biological and Chemical/Physicochemical Pretreatment Methods of Lignocellulosic Biomass for Bioethanol and Biomethane Energy Production—A Review

Lignocellulosic biomass is a low-cost and environmentally-friendly resource that can be used to produce biofuels such as bioethanol and biogas, which are the leading candidates for the partial substitution of fossil fuels. However, the main challenge of using lignocellulosic materials for biofuel production is the low accessibility to cellulose for hydrolysis of enzymes and microorganisms, which can be overcome by pretreatment. Biological and chemical pretreatments have their own disadvantages, which could be reduced by combining the two methods. In this article, we review biological–chemical combined pretreatment strategies for biogas and bioethanol production. The synergy of fungal/enzyme–NaOH pretreatment is the only biological–chemical combination studied for biogas production and has proven to be effective. The use of enzyme, which is relatively expensive, has the advantage of hydrolysis efficiency compared to fungi. Nonetheless, there is vast scope for research and development of other chemical–biological combinations for biogas production. With respect to ethanol production, fungal–organosolv combination is widely studied and can achieve a maximum of 82% theoretical yield. Order of pretreatment is also important, as fungi may reduce the accessibility of cellulose made available by prior chemical strategies and suppress lignin degradation. The biofuel yield of similarly pretreated biomass can vary depending on the downstream process. Therefore, new strategies, such as bioaugmentation and genetically engineered strains, could help to further intensify biofuel yields.

A novel approach on the delineation of a multipurpose energy-greenbelt to produce biofuel and combat desertification in arid regions

Jatropha curcas L. (JCL) is one of the most prominent energy crops due to its superior agronomical traits, where it can grow in non-arable lands and harsh climates with minimal water requirements. A significant number of studies were published on the utilisation of JCL for biofuel production, whereas there are no studies on its use in greenbelt (GB) or windbreak technologies reported thus far. Meanwhile, a few approaches on the delineation of greenbelts to fight desertification in the arid regions exist in literature. This study presents a novel approach to delineate a multipurpose energy-greenbelt using JCL crop for biofuel production, as well as to preserve the soil and enhance air quality, thereby helping to combat desertification and sand-dust storms (SDS). The methodology is demonstrated using a case study in the state of Qatar for the diversification of its renewable energy resources. Moreover, Qatar is also suffering from land degradation due to erosion factors and desert creep. A multi-dimensional approach is proposed for this purpose using satellite and meteorological data to initially select the optimal plantation sites that potentially contribute to the highest possible biofuel yield. The spatial analysis was carried out using the analytical hierarchy process (AHP) technique for multi-criteria decision making in the geographic information system (ArcGIS). In addition, the Landsat and MODIS satellite imagery were utilised in combination with historical records from the weather stations to evaluate the patterns of SDS, land degradation and urban expansion, to best define optimal GB pathway. COMSOL Multiphysics software was subsequently employed to evaluate the performance of Jatropha-GB and determine its optimal density. The different solutions for GB delineation spans 166.6–227.8 km length and (6 × 6 m) of field density. It is expected that the economic and environmental benefits from the derived GB configuration include: (a) protection of up to 87% of Qatar farms against further deterioration; (b) yield of up to 36 M gallon of green liquid fuels; (c) capture of 0.33 M tonnes of CO2 per 1 km GB-depth annually; and (d) provide a better air quality for around 95% of the Qatar population.

Rubber seed oil: Potential feedstock for aviation biofuel production

The aviation industry is responsible for 12% of transport-related GHG emissions and 2–3% of the global GHG emissions, thus raising concerns for sustainable alternatives such as aviation biofuels. This study sought to analyze the potential of producing aviation fuel from rubber seed oil. Rubber seed oil (RSO) was extracted and the physicochemical properties investigated as well as the fatty acid composition. This result was simulated in ASPEN plus to determine the potential aviation biofuel produced using the UOP HEFA process. The study shows that the golden yellowish oil derived from rubber seed possessed a density 0.9 g/cm3 and pH of 6, refractive index of 1.48, heating value of 23.75 MJ/kg and composed of 75% area of FFA with Oleic and Linoleic acid been the most dominant. The HEFA process on ASPEN Plus showed 81% of feedstock was converted to hydrocarbons with aviation biofuel yield of 46%. It was estimated that the installation of the plant for aviation biofuel production has a total capital cost of $ 8,650,480 and a total operation cost of $ 328,728. The economic analysis shows that at a cost of USD 4/kg (USD 3.01/liter) of aviation biofuel has an Internal rate of return of 18.62% profitability of 1.18 and payback period of 14.9 years of the plant operating. This study established that rubber seed oil shows suitability and potential for sustainable aviation biofuel production.

Optimization of Biofuel Production from Used Cooking Oil Using Natural Zeolite Catalyst

Petroleum is still the primary energy used in the world. Its diminishing production is the trigger to find alternative energy to replace it. Biofuel is an alternative energy that has the potential to replace petroleum because it is renewable, environmentally friendly, and easy raw material. Waste such as used cooking oil can be used as raw material for making biofuels. The low price can reduce the cost of biofuel production. The conversion of oil into biofuel can be done using catalytic cracking with natural zeolite as a catalyst. This study aims to determine the optimum conditions for making biofuel from used cooking oil and determine its physical and chemical properties. The catalytic cracking process is carried out using an autoclave reactor. Used cooking oil and natural zeolite were introduced into the reactor, and the reaction was carried out by varying the time (1, 2, 3 hours), temperature (325, 350, 375 o C), catalyst concentration (3, 5, 7%), and catalyst size. The product is distilled to produce biofuel (liquid), gas, and residue. The optimization results show that 3 hours, a temperature of 375 o C, a catalyst concentration of 7%, and a catalyst size of 180 µm are the optimum conditions for catalytic cracking with 44.94% biofuel yield. The resulting biofuel contains 73.48% hydrocarbons and 26.52% fatty acids. The hydrocarbon composition consists of 19.32% gasoline, 12.82% kerosene, and 35.11% diesel. The density of the biofuel produced is 0.8835g/mL, the flashpoint is 68 o C, and the pourpoint is 27 o C.

Supercritical ethanol liquefaction of rice husk to bio-fuel over modified graphene oxide

An increase in the energy system used promote new renewable source produced to improve human well-being quality. The objective of this work is to study the supercritical ethanol liquefaction reaction using rice husk as a feedstock and graphene oxide as catalyst. Characterization of the catalyst was conducted using thermal gravimetry analysis technique and N2 Sorption. Results revealed that graphene oxide treated with 1.5 M sulfuric acid solution gave the largest surface area of 110.5 m2/g. This research promised to optimize bio-fuel production using Box–Behnken method with 15 experimental data. The significant of the 3 parameters (catalyst amount, temperature and reaction time) was demonstrated using the ANOVA method. These statistical data were employed to illustrate contour data and response surface. A polynomial equation was also derived from the experimental data and used to valid with calculated data from the equation. Optimization was discussed in term of yield and operating cost. Optimum conditions were of 51.8% bio-fuel yield were derived from supercritical ethanol liquefaction at reaction time of 298 °C, 60 min reaction time, and 3.4 grams of SO4(1.5)/GO catalyst. Bio-fuel derived the optimum condition gave a high heating value as high as 30.15 MJ/kg, which is in the range of transportation fuel.

ЕНЕРГЕТИЧНА ПРОДУКТИВНІСТЬ СОРГО ЗЕРНОВОГО ТА СОРИЗУ ЗАЛЕЖНО ВІД СТРОКІВ СІВБИ НАСІННЯ

The article presents the results of research on the influence of seed sowing dates on the energy productivity of grain sorghum and sorghum. Goal. Investigate the influence of seed sowing dates on the energy productivity of grain sorghum and varieties of Dniprovsky 39 and Samaran 6 varieties in the conditions of the eastern part of the Forest-Steppe of Ukraine. Methods. The field method was used in the study, which includes the study of biological and ecological features of growth and development, productivity and quality of the studied crop; laboratory method used to study the relationship between plant and environment; mathematical and statistical methods included the processing of experimental data to increase the validity of conclusions. Results. High yields of sorghum grain and biomass were obtained during sowing of seeds in the first decade of May (second sowing period), when the soil temperature at a depth of 10 cm was 12-14 оС. In grain sorghum of Dniprovskyi 39 and Samaran 6, grain yield was 7.1 and 6.4 t/ha, biomass – 37.4 and 35.9 t/ha. The highest yield of bioethanol and solid fuel was obtained in the same variant of the experiment. The highest energy yield was obtained for sowing seeds in the first decade of May and was equal to 199.3 GJ/ha in the variety Dniprovsky 39 and 187.9 GJ/ha in the variety Samaran 6. About 71.0-72.0 % are concentrated in solid fuel (140,8 and 135.2 GJ/ha) of this energy and in bioethanol only 28-29 % (51.1 and 52.7 GJ/ha). Conclusions. It was studied that the grain yield and biomass of sorghum and sorghum mostly depend on the terms of sowing seeds – 29.2 %, the degree of influence of varieties was much lower and amounted to 8.1%. It is established that in comparison with the optimal sowing dates – the first and second decades of May, sowing seeds in the third decade of April (I sowing period) reduces grain yield by 4.2-12.6 % in the variety Dniprovsky 39 and 4.7-9,4 % in the variety Samaran 6; aboveground mass by 4.8-9.6 % and 6.4-10.6 %, respectively. Correlation-regression analysis of the data shows a close relationship between yield and biofuel yield. The correlation coefficient was R = 1, the coefficient of determination R2 = 1. There is also a strong correlation between yield and energy yield where R = 1, the coefficient of determination R2 = 1. Key words: varieties, yield, yield of biethanol and solid fuel, energy yield.

Potential Techniques for Conversion of Lignocellulosic Biomass into Biofuels

Lignin has been found as a naturally available aromatic resource for biofuel production. Reduced reliance on fossil fuels and replacement with a green and environmentally friendly strategy are currently one of the most pressing challenges. There has been significant growth in energy consumption, necessitating the transition to an alternative energy source. The current renewable energy source has significant biofuel production potential. It is critical to discuss the process parameters for pinpointing lignin content as part of the technology development process. Biofuel production possesses various challenges that need to be addressed. In this research, we precisely discussed the numerous lignin conversion mechanisms that can boost the biofuel output. Catalytic deoxygenation is a fuel promotion process that decreases the oxygen content, which causes instability and corrosion. SiO2, ZrO2, CeO2, TiO2, and Al2O3 are used in catalytic deoxygenation to produce biofuel. The use of chosen Al2O3-TiO2 metal oxide catalysts is critical in biofuel production. To obtain hemicellulose levels, two-step pretreatments with alkali and acids are used. The constraints, challenges, industrial perspectives, and future outlooks for developing cost-effective, energy-efficient, and environmentally friendly procedures for the long-term valorization of lignocellulosic materials were examined in the conclusion.

Light biofuel production from waste cooking oil via pyrolytic catalysis cracking over modified Thai dolomite catalysts

Renewable biofuels have gained increasing attention as a potential alternative fuel to decrease CO2 emission from combustion of fossil fuels. The aims of the work were to modify Thai dolomite by adding magnesium carbonate (MgCO3) at various contents (0–30 wt%), and used as catalyst in pyrolytic catalysis cracking (PCC) process to produce light biofuels including gasoline and kerosene. All catalysts were calcined at 600 °C for 4 h prior to the characterization and experiments. The physicochemical properties were done by various techniques such as X-ray diffractometer (XRD), N2 adsorption–desorption, thermogravimetric analyzer and differential thermal analyzer (TGA-DTA), Field-emission scanning electron microscope (FE-SEM), and energy dispersive X-ray spectroscopy (EDX). The experiments of PCC process were carried out at different reaction temperatures of 450–550 °C. The results from XRD and SEM-EDX confirmed that the Mg was successfully added in Thai dolomite. The Mg content in the catalysts increased with increasing MgCO3 loadings. The calcination temperature of 600 °C cannot completely convert CaCO3 to CaO form. The pyrolytic oil and distilled oil yields and quality were affected by both Mg content and reaction temperature. In addition, pyrolytic oil was completely distillated according to ASTM D86 to separate into gasoline, kerosene, and diesel. The light biofuel production was enhanced with increasing Mg content in the reaction temperatures of 500 and 550 °C. The appropriate condition was suggested at reaction temperature of 500 °C with 20 wt% Mg/dolomite catalyst as it showed the highest production yield of about 84 vol% and light biofuel yield of about 65 vol%.

Role of nanotechnology for the conversion of lignocellulosic biomass into biopotent energy: A biorefinery approach for waste to value-added products

The development of low-cost bioenergy from the world's most abundant lignocellulosic biomass (LCB) is critical, as is tackling the issue of environmental contamination. In this context, nanomaterials have been used as catalysts for the production of sugars and derivative compounds that are easily absorbed by LCB cells. NPs derived from microorganisms can protect fermenting strains, hence increasing biofuel yield. Enzymes immobilised on nanoparticles or coupled with nanomaterials can be used to hydrolyze LCB in unique and ecologically friendly methods. Nanomaterials improve the efficiency, reusability, and stability of enzymes. Magnetic nanoparticles, in particular, have carved out a place for themselves through the process of downstreaming LCB effluents at a significant cost savings and increased efficiency. The role of nanotechnology and nanoparticles in the refining of LCB into a variety of commercially valuable products and precursors is highlighted in this review. This article successfully illustrates the relationship between nanotechnology concepts and the LCB refinery process.

Co‐pyrolysis of a coal/biomass blend into biofuel: optimization of operational parameters using central composite design

AbstractResearchers are attempting to replace fossil and petro‐based fuels with renewable and green fuels. Knowing the optimum values of pyrolysis parameters during the production of biofuel from biomass/coal blends is important to obtain biofuel in the desired yield and quality. In this study, a central composite design was used in order to optimize pyrolysis parameters to obtain biofuel from the co‐pyrolysis of a coal (lignite)/biomass (pistachio seeds) mixture in a well‐swept resistance fixed bed reactor. Knowing the optimum values ​​of different parameters affecting the biofuel yield and quality is very important in terms of the most efficient conditions and the economical production of energy. The effects of some operational parameters, like final temperature (factor A), heating rate (factor B) and percentage of lignite (factor C), were optimized through the central composite design method, and their behaviors were analyzed using analysis of variance. While the linear and quadratic effects of the final temperature and heating rate on the biofuel yield were significant, only the linear effect of the percentage of lignite was found to be important; on the other hand, the effects of the binary interaction between the factors were found to be insignificant. A quadratic equation was proposed to predict the behavior of the process under various conditions with an R2 of 98.19. The best condition was predicted at a final temperature of 595 °C, a heating rate of 458 °C/min and a percentage lignite of 16.7% with maximum biofuel yield of 61.23%. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd

Conversion of carbon dioxide to value added products through anaerobic fermentation and electro fermentation: A comparative approach

Increasing carbon footprint alters the carbon balance in nature, thereby worsening global climate change. The conversion of carbon dioxide (CO 2 ) into value-added products through biological routes is the pathway of the future because of its ecological and sustainable character. The present study evaluated the conversion of CO 2 into short-chain fatty acids (SCFA)/volatile fatty acids (VFA) and methane using four experimental conditions (R1-R4). The experimental conditions are R1 was an anaerobic fermenter (AF) operated as control, R2 consisted of an AF with electrodes operated in open circuit, R3 was an AF with electrodes operated in a closed circuit with 100 Ω as load and R4 was an electro-fermentation reactor with an applied cathodic potential of −0.8 V vs. Ag/AgCl. The results were assessed in terms of production of SCFA, methane, current density and inorganic carbon reduction. Electro-fermentation (R4) setup achieved the highest production of SCFA (2050 mg/L) and methane (41.2 mL/day) compared to other reactors. R3 reported 1800 mg/L and 24 mL/day, R2 reported 1560 mg/L and 15 mL/day and R1 reported 1430 mg/L and 10 mL/day of methane and SCFA production. The study-inferred that electro-fermentation could effectively catalyse the biochemical reactions and enhance the conversion of CO 2 to organic compounds in a sustainable manner. • Presence of electrode in the anaerobic fermentation enhanced the yield of carboxylic acids and biofuels. • The redox conditions are balanced in the microbial catalysed systems than the conventional anaerobic fermentations. • Enriched microbes showed different yield based on the operational conditions. • Electrofermentation is an effective processes to convert CO 2 to Value added products.

Bioethanol and biogas production: an alternative valorisation pathway for green waste

Biofuels are a research field of great interest given the environmental benefits they offer over conventional fossil fuels. Nowadays, it is urgent to find ways of utilizing waste in the direction of biofuels production. The aim of this paper was the utilization of green waste (branches, leaves and ligno-cellulosic residues from tree prunings, hedge cuttings and grass clippings) towards biofuels production and specifically towards bioethanol and biogas. The experimental plan that was followed included biogas production through anaerobic digestion and bioethanol production through alcoholic fermentation after the necessary chemical pretreatment (acid or alkaline hydrolysis) prior to enzymatic hydrolysis and fermentation. Based on the results obtained, three valorisation scenarios of green waste were designed and compared in terms of product mass intensity, product yield and energy content of biofuels produced. The optimal results for bioethanol production were 5.22 g/L ethanol, 70.61% saccharification yield and 33.67% ethanol yield with acid pretreatment using H2SO4 3% w/v, 475 μL/g cellulose CellicCtec2 and 10% solids loading. Regarding biogas, the highest biogas production observed was 267.1 mL biogas/g dry substrate resulting from anaerobic digestion of the alkaline stillage. Thus, the production of biofuels from green waste is technically feasible, although it provides moderate efficiencies. However, for a sustainable valorisation of green waste, other techno-economic factors such as the cost of enzymes, chemicals, energy, etc. must be taken into account.

Electrochemistry and fermentation combine to increase biofuel yields and recycle CO2

The January 2022 issue of Membrane Technology reported that De Nora, which specialises in industrial electrochemistry, is part of project funded by the US Department of Energy to develop emissions-free biofuel technology. As a follow-up, this focus article briefly looks the role the company is playing, the way in which its technology is being used and how the project itself is part of a wider programme that aims to optimise biofuel manufacturing.

Production of Liquid Biofuels from Microalgae Chlorella sp. via Catalytic Slow Pyrolysis

This study investigates the effects of catalyst preparation techniques on the yield and quality of liquid biofuel produced from slow catalytic pyrolysis of microalgae Chlorella sp. using various catalysts, including acid catalysts (HZSM-5) and bas

Chemical-switching strategy for the production of green biofuel on NiCo/MCM-41 catalysts by tuning atmosphere

NiCo bimetallic catalyst was one of potential candidates used toward the hydrodeoxygenation of vegetable oils. However, there is still lack for digging out the relationship between micro-structure pretreated by various atmosphere and its catalytic performance. To hunting the relationship, NiCo/MCM-41 precursor was synthesized via the conventional co-impregnation method, and further pretreated by different atmospheres, including NH3, CH4/H2 and H2 in order to tune the particle size, active component dispersion, and acid properties of the catalysts. NiCo/MCM-41-H pretreated by H2 exhibits superior catalytic performance (65.8 wt% biofuel yield and 98.2% C12-C18 alkanes selectivity) on converting jatropha oil than that by NH3 and by CH4/H2. For comparison, the NiCo/MCM-41-H shows the smallest NiCo alloy grains, the smallest amount of strong acid, the lowest Brønsted acid/Lewis acid ratio, and the most uniform dispersion of Ni and Co. All the distinct surface properties of NiCo/MCM-41-H reasonably account for high efficiency in hydrodeoxygenation of jatropha oil. The work reveals the relationship between NiCo bimetallic catalyst structure and its hydrodeoxygenation performance, and provides a robust pretreatment method for tuning the surface properties to improve its catalytic performance for converting biomass oils into green biofuel.

ВИРОЩУВАННЯ ЕНЕРГЕТИЧНОЇ ВЕРБИ В УМОВАХ ЗАХІДНОГО ПОЛІССЯ

The research results of influence of the planting density, fertilization and soil type on the productivity of the energy willow in the conditions of Western Polissia are presented. On average over five years of research in the cultivation of energy willow it was found that the highest yield of dry biomass 102.9 t/ha was obtained on dark gray light loamy soil with a planting density of 20 thousand pcs/ha and fertilizer application at the rate of N60 P200 K200. The lowest yield of dry biomass was at planting density of energy willow of 10 thousand pcs/ha in the variant without fertilizers on dark gray light loamy soil and sod-podzolic cohesive sandy soil – 49.1 and 26.9 t/ha, respectively. The mineral fertilizer application with rate of N60 P100 K100 ensured an increase in the yield of dry biomass by 13.5 and 7.5 t/ha depending on the type of soil. The increase of phosphorus and potash fertilizers rate to 200 kg a.i./ha contributed to an increase in dry mass up to 23.6 and 13.0 t/ha compared to the variant without fertilizers. A similar result was obtained on sod-podzolic cohesive-sandy soil. The lowest indicators were in the variant without fertilizers at the planting density of 10 thousand pcs/ha – 26.9 t/ha, 15 thousand pcs/ha – 30.2 t/ha and 20 thousand рcs/ha – 35.6 t/ha dry biomass. The application of mineral fertilizers with rate of N60P100K100 for all planting densities increased the dry biomass yield to 34.4; 38.5; 45.3 t/ha, respectively. Increase of phosphorus and potash fertilizers rate up to 200 kg a.i./ha against the background of N60 contributed to an increase of energy willow yield up to 39.9 t/ha (with a planting density of 10 thousand pcs/ha), 44.1 t/ha (15 thousand pcs/ha) and 52.3 t/ha (20 thousand pcs/ha) of dry biomass. On average for five years, the application of fertilizer with N60P200K200 rate on dark gray light loamy soil, and at planting density of 20 thousand pcs/ha provided the highest yield of solid biofuel from energy willow of 22.7 t/ha and energy of 363 GJ/ha, while on sod-podzolic cohesive-sandy soil under the same growing conditions the yield of solid biofuel from willow was less by 11.1 t/ha and energy of 178 GJ/ha. Keywords: energy willow, dry biomass, solid biofuels, energy, soil.

A Multisectoral Dynamic Model for Energy, Economic, and Climate Scenario Analysis

The MIT Economic Projection and Policy Analysis (EPPA) model has been widely used in energy, land use, technology, and climate policy studies. Here, we provide details of revisions that form the basis of EPPA7, the current version. Key updates include: 1) using the latest Global Trade Analysis Project (GTAP-power) database as the core economic data for the world economy; 2) updating regional economic growth projections; 3) separating extant and vintage capital of the previously aggregated fossil generation; 4) using an innovative approach to calculate the costs of backstop (i.e., advanced) power generation options based on engineering data from the Energy Information Administration; 5) identifying base year biofuel output from existing sectors; and 6) re-parameterizing electric vehicles based on recent studies. Our simulations demonstrate that with widespread mitigation policies worldwide, regions relying heavily on fossil fuel imports benefit from lower global fossil fuel prices when their domestic emissions targets are lenient, but the benefits dissipate when deeper emissions cuts are imposed domestically. We also provide an illustration how the model output can be used to calculate the net present values of unrealized fossil fuel production and stranded assets from idling coal power generation under various policy scenarios.

Measurement and Importance of Volatile Matter in Coals and Biofuels

Abstract Volatile matter values for solid fuels are used to assess their burning rates and, thus, provide a basis for the buying and selling of these fuels. The major factors that affect volatile matter yields are the type of fuel, moisture contents, and the heating rates used in the tests. This paper reports the results of experiments designed to improve the reliability and application of test methods for the determination of volatile matter in various solid fuels. The macro thermogravimetric analysis studies described herein include the rapid drying of analysis samples of coal and the effect on volatile matter yields, the heating of various chars at high temperatures to reach a state of constancy, the measuring of decomposition moisture, an “elusive” constituent in coal, and the cocombustion of coals and other solid fuels. The presence of residual moisture and decomposition moisture in the coal during the volatile matter tests increases the measured volatile matter yields even though the residual moisture has been factored out. The rates of heating solid fuels during volatile matter tests affect the volatile matter yields because of the presence of different types of moisture in the fuel that are released at different temperatures. The heating rates used in volatile matter tests affect the type of compounds released and the total volatile matter yields of coals and biofuels. The experiments reported in this paper were instrumental in the decision of ASTM Committee D05 on Coal and Coke to recently revise the classic volatile matter standard test method D3175 to change the temperature for drying sparking coals from 600°C to 107°C. The role volatile matter plays in the combustion of fuel blends is discussed in this article.