Showing papers in "Biomass & Bioenergy in 2005"
TL;DR: In this paper, the state of the art of hydrolysis-fermentation technologies to produce ethanol from lignocellulosic biomass, as well as developing technologies, are evaluated.
Abstract: The state of the art of hydrolysis-fermentation technologies to produce ethanol from lignocellulosic biomass, as well as developing technologies, is evaluated. Promising conversion concepts for the short-, middle- and long-term are defined. Their technical performance was analysed, and results were used for economic evaluations. The current available technology, which is based on dilute acid hydrolysis, has about 35% efficiency (HHV) from biomass to ethanol. The overall efficiency, with electricity co-produced from the not fermentable lignin, is about 60%. Improvements in pre-treatment and advances in biotechnology, especially through process combinations can bring the ethanol efficiency to 48% and the overall process efficiency to 68%. We estimate current investment costs at 2.1 k€/kW HHV (at 400 MW HHV input, i.e. a nominal 2000 tonne dry/day input). A future technology in a 5 times larger plant (2 GW HHV ) could have investments of 900 k€/kW HHV . A combined effect of higher hydrolysis-fermentation efficiency, lower specific capital investments, increase of scale and cheaper biomass feedstock costs (from 3 to 2 €/GJ HHV ), could bring the ethanol production costs from 22 €/GJ HHV in the next 5 years, to 13 €/GJ over the 10–15 year time scale, and down to 8.7 €/GJ in 20 or more years.
1,683 citations
TL;DR: A 10-year US Department of Energy sponsored research program designed to evaluate and develop switchgrass ( Panicum virgatum ), a native perennial warm-season grass, as a dedicated energy crop is reviewed in this paper.
Abstract: A 10-year US Department of Energy-sponsored research program designed to evaluate and develop switchgrass ( Panicum virgatum ), a native perennial warm-season grass, as a dedicated energy crop is reviewed. The programmatic objectives were to identify the best varieties and management practices to optimize productivity, while developing an understanding of the basis for long-term improvement of switchgrass through breeding and sustainable production in conventional agroecosystems. This research has reduced the projected production cost of switchgrass by about 25% ($8–9 Mg −1 ) through yield increases of about 50% achieved through selection of the best regionally adapted varieties; through optimizing cutting frequency and timing; and by reducing the level (by about 40%) and timing of nitrogen fertilization. Breeding research has made further gains in productivity of switchgrass that exceed the historical rate of yield improvement of corn. Studies of soil carbon storage under switchgrass indicate significant carbon sequestration will occur in soils that will improve soil productivity and nutrient cycling and can substantially augment greenhouse gas reductions associated with substituting renewable energy for fossil energy. Collaborative research with industry has included fuel production and handling in power production, herbicide testing and licensing, release of new cultivars, and genetic modifications for chemical coproduct enhancement. Economically based life cycle analyses based on this research suggest that switchgrass produced for energy will compete favorably both as an agricultural crop and as fuel for industry.
1,062 citations
TL;DR: In this paper, Saponification number (SN), iodine value (IV) and cetane number (CN) of seed oils were empirically determined and they varied from 169.2 to 312.5, 4.8 to 212 and 20.56 to 67.47, respectively.
Abstract: Fatty acid profiles of seed oils of 75 plant species having 30% or more fixed oil in their seed/kernel were examined. Saponification number (SN), iodine value (IV) and cetane number (CN) of fatty acid methyl esters of oils were empirically determined and they varied from 169.2 to 312.5, 4.8 to 212 and 20.56 to 67.47, respectively. Fatty acid compositions, IV and CN were used to predict the quality of fatty acid methyl esters of oil for use as biodiesel. Fatty acid methyl ester of oils of 26 species including Azadirachta indica, Calophyllum inophyllum, Jatropha curcas and Pongamia pinnata were found most suitable for use as biodiesel and they meet the major specification of biodiesel standards of USA, Germany and European Standard Organization. The fatty acid methyl esters of another 11 species meet the specification of biodiesel standard of USA only. These selected plants have great potential for biodiesel.
961 citations
TL;DR: In this article, the authors proposed a new correlation between the heating value and dry ash content of biomass (in weight percent, wt%) (i.e. HHV (MJ/kg) = 19.914-0.2324 Ash) to estimate the HHV from proximate analysis.
Abstract: The heating value is one of the most important properties of biomass fuels for design calculations or numerical simulations of thermal conversion systems for biomass. There are a number of formulae proposed in the literature to estimate the higher heating value (HHV) of biomass fuels from the basic analysis data, i.e. proximate, ultimate and chemical analysis composition. In the present paper, these correlations were evaluated statistically based on a larger database of biomass samples collected from the open literature. It was found that the correlations based on ultimate analysis are the most accurate. The correlations based on the proximate data have low accuracy because the proximate analysis provides only an empirical composition of the biomass. The correlations based on the bio-chemical composition are not reliable because of the variation of the components properties. The low accuracy of previous correlations is mainly due to the limitation of samples used for deriving them. To achieve a higher accuracy, new correlations were proposed to estimate the HHV from the proximate and ultimate analyses based on the current database. The new correlation between the HHV and dry ash content of biomass (in weight percent, wt%) (i.e. HHV (MJ/kg) = 19.914–0.2324 Ash) could be conveniently used to estimate the HHV from proximate analysis. The new formula, based on the composition of main elements (in wt%) C, H, and O (i.e. HHV ( MJ / kg ) = - 1.3675 + 0.3137 C + 0.7009 H + 0.0318 O * ), is the most accurate one, with more than 90% predictions in the range of ± 5 % error.
800 citations
TL;DR: The current status of biomass gasification in near and supercritical water (SCWG) is reviewed in this article, where two approaches for SCWG are compared: low-temperature catalytic gasification, which employs reaction temperature ranging from 350 to 600 °C, and gasifies the feedstock with the aid of metal catalysts.
Abstract: The current status of biomass gasification in near- and supercritical water (SCWG) is reviewed. There are two approaches to biomass gasification in supercritical water. The first: low-temperature catalytic gasification, employs reaction temperature ranging from 350 to 600 °C, and gasifies the feedstock with the aid of metal catalysts. The second: high-temperature supercritical water gasification, employs reaction temperatures ranging from 500 to 750 °C, without catalyst or with non-metallic catalysts. Reviews are made on reaction mechanism, catalyst, and experimental results for these two approaches. Engineering technologies for SCWG gasification, and an example of process analysis are also introduced. Finally, the authors’ prognostications on the future prospects of this technology are offered.
667 citations
TL;DR: A technique to produce biodiesel from mahua oil (Madhuca indica) having high free fatty acids (19% FFA) has been developed in this paper, where a two-step pretreatment process was carried out with 0.30-0.35 v/v methanol-to-oil ratio in the presence of 1% v/V H 2 SO 4 as an acid catalyst in 1-hour reaction at 60°C.
Abstract: A technique to produce biodiesel from mahua oil ( Madhuca indica ) having high free fatty acids (19% FFA) has been developed. The high FFA level of mahua oil was reduced to less than 1% by a two-step pretreatment process. Each step was carried out with 0.30–0.35 v/v methanol-to-oil ratio in the presence of 1% v/v H 2 SO 4 as an acid catalyst in 1-hour reaction at 60°C. After the reaction, the mixture was allowed to settle for an hour and methanol–water mixture that separated at the top was removed. The second step product at the bottom was transesterified using 0.25 v/v methanol and 0.7% w/v KOH as alkaline catalyst to produce biodiesel. The fuel properties of mahua biodiesel were found to be comparable to those of diesel and conforming to both the American and European standards.
627 citations
TL;DR: In this paper, the authors investigated and evaluated the feasibility of biomass utilization for direct production of electric energy by means of combustion and gasification conversion processes, taking into account total capital investments, revenues from energy sale and total operating costs, also including a detailed evaluation of logistic costs.
Abstract: The substitution of conventional fossil fuels with biomass for energy production results both in a net reduction of greenhouse gases emissions and in the replacement of non-renewable energy sources. However, at present, generating energy from biomass is rather expensive due to both technological limits related to lower conversion efficiencies, and logistic constraints. In particular, the logistics of biomass fuel supply is likely to be complex owing to the intrinsic feedstock characteristics, such as the limited period of availability and the scattered geographical distribution over the territory. In this paper, the economical feasibility of biomass utilization for direct production of electric energy by means of combustion and gasification-conversion processes, has been investigated and evaluated over a capacity range from 5 to 50 MW, taking into account total capital investments, revenues from energy sale and total operating costs, also including a detailed evaluation of logistic costs. Moreover, in order to evaluate the impact of logistics on the bio-energy plants profitability, the effects of main logistic variables such as specific vehicle transport costs, vehicles capacity, specific purchased biomass costs and distribution density, have been examined. Finally, a mapping of logistic constraints on plant profitability in the specified capacity range has been carried out.
618 citations
TL;DR: In this article, a life cycle assessment of different cropping systems emphasizing corn and soybean production was performed, assuming that biomass from the cropping system is utilized for producing biofuels (i.e., ethanol and biodiesel).
Abstract: A life cycle assessment of different cropping systems emphasizing corn and soybean production was performed, assuming that biomass from the cropping systems is utilized for producing biofuels (i.e., ethanol and biodiesel). The functional unit is defined as 1 ha of arable land producing biomass for biofuels to compare the environmental performance of the different cropping systems. The external functions are allocated by introducing alternative product systems (the system expansion allocation approach). Nonrenewable energy consumption, global warming impact, acidification and eutrophication are considered as potential environmental impacts and estimated by characterization factors given by the United States Environmental Protection Agency (EPA-TRACI). The benefits of corn stover removal are (1) lower nitrogen related environmental burdens from the soil, (2) higher ethanol production rate per unit arable land, and (3) energy recovery from lignin-rich fermentation residues, while the disadvantages of corn stover removal are a lower accumulation rate of soil organic carbon and higher fuel consumption in harvesting corn stover. Planting winter cover crops can compensate for some disadvantages (i.e., soil organic carbon levels and soil erosion) of removing corn stover. Cover crops also permit more corn stover to be harvested. Thus, utilization of corn stover and winter cover crops can improve the eco-efficiency of the cropping systems. When biomass from the cropping systems is utilized for biofuel production, all the cropping systems studied here offer environmental benefits in terms of nonrenewable energy consumption and global warming impact. Therefore utilizing biomass for biofuels would save nonrenewable energy, and reduce greenhouse gases. However, unless additional measures such as planting cover crops were taken, utilization of biomass for biofuels would also tend to increase acidification and eutrophication, primarily because large nitrogen (and phosphorus)-related environmental burdens are released from the soil during cultivation.
530 citations
TL;DR: In this paper, the authors analyzed the geographical and technical potential of energy crops for the years 2050-2100 for three land-use categories: abandoned agricultural land, low-productivity land and rest land, i.e. remaining noproductive land.
Abstract: The availability of the resources is an important factor for high shares of biomass to penetrate the electricity, heat or liquid fuel markets. We have analysed the geographical and technical potential of energy crops for the years 2050–2100 for three land-use categories: abandoned agricultural land, low-productivity land and ‘rest land’, i.e. remaining noproductive land. We envisaged development paths using four scenarios resulting from different future land-use patterns that were developed by the Intergovernmental Panel on Climate Change in its Special Report on Emission Scenarios: A1, A2, B1 and B2. The geographical potential is defined as the product of the available area for energy crops and the corresponding productivity level for energy crops. The geographical potential of abandoned agricultural land is the largest contributor. For the year 2050 the geographical potential of abandoned land ranges from about 130 to 410 EJ yr � 1 . For the year 2100 it ranges from 240 to 850 EJ yr � 1 . The potential of low-productive land is negligible compared to the other categories. The rest land area is assumed to be partly available, resulting in ranges of the geographical potential from about 35 to 245 EJ yr � 1 for the year 2050 and from about 35 to 265 EJ yr � 1 in 2100. At a regional level, significant potentials are found in the Former USSR, East Asia and South America. The geographical potential can be converted to transportation fuels or electricity resulting in ranges of the technical potential for fuels in the year 2050 and 2100 equal to several times the present oil consumption. r 2005 Elsevier Ltd. All rights reserved.
458 citations
TL;DR: In this article, a tool was developed to consistently compare the possible bioenergy supply chains and assess the influence of key parameters, such as distance, timing and scale on performance, on performance.
Abstract: To supply biomass from production areas to energy importing regions, long-distance international transport is necessary, implying additional logistics, costs, energy consumption and material losses compared to local utilisation. A broad variety of bioenergy chains can be envisioned, comprising different biomass feedstock production systems, pre-treatment and conversion operations, and transport of raw and refined solid biomass and liquid bio-derived fuels. A tool was developed to consistently compare the possible bioenergy supply chains and assess the influence of key parameters, such as distance, timing and scale on performance. Chains of European and Latin American bioenergy carriers delivered to Western Europe were analysed using generic data. European biomass residues and crops can be delivered at 90 and 70 €/tonne dry (4.7 and 3.7 €/GJ HHV ) when shipped as pellets. South American crops are produced against much lower costs. Despite the long shipping distance, the costs in the receiving harbour can be as low as 40 €/tonne dry or 2.1 €/GJ HHV ; the crop's costs account for 25–40% of the delivered costs. The relatively expensive truck transport from production site to gathering point restricts the size of the production area; therefore, a high biomass yield per hectare is vital to enable large-scale systems. In all, 300 MW HHV Latin American biomass in biomass integrated gasification/combined cycle plants may result in cost of electricity as little as 3.5 €cent/kWh, competitive with fossil electricity. Methanol produced in Latin America and delivered to Europe may cost 8–10 €/GJ HHV , when the pellets to methanol conversion is done in Europe the delivered methanol costs are higher. The energy requirement to deliver solid biomass from both crops and residues from the different production countries is 1.2–1.3 MJ primary /MJ delivered (coal ∼1.1 MJ/MJ). International bioenergy trade is possible against low costs and modest energy loss.
404 citations
TL;DR: In this article, Mahua oil (Madhuca indica seed oil) was transesterified with methanol using sodium hydroxide as catalyst to obtain mahua oil methyl ester.
Abstract: There is an increasing interest in many countries to search for suitable alternative fuels that are environment friendly. Although straight vegetable oils can be used in diesel engines, their high viscosities, low volatilities and poor cold flow properties have led to the investigation of various derivatives. Biodiesel is a fatty acid alkyl ester, which can be derived from any vegetable oil by transesterification. Biodiesel is a renewable, biodegradable and non-toxic fuel. In this study, Mahua oil (Madhuca indica seed oil) was transesterified with methanol using sodium hydroxide as catalyst to obtain mahua oil methyl ester. This biodiesel was tested in a single cylinder, four stroke, direct injection, constant speed, compression ignition diesel engine (Kirloskar) to evaluate the performance and emissions.
TL;DR: In this paper, a review of literature on employment and other socioeconomic aspects of bioenergy systems as drivers for implementing bioenergy projects is presented, and the authors aim to trigger a more in-depth discussion of data gaps, potentials, opportunities and challenges.
Abstract: Within the international community there is considerable interest in the socio-economic implications of moving society towards the more widespread use of renewable energy resources. Such change is seen to be very necessary but is often poorly communicated to people and communities who need to accept such changes. There are pockets of activity across the world looking at various approaches to understand this fundamental matter. Typically, socio-economic implications are measured in terms of economic indices, such as employment and monetary gains, but in effect the analysis relates to a number of aspects which include social, cultural, institutional, and environmental issues. The extremely complex nature of bioenergy, many different technologies involved and a number of different, associated aspects (socio-economics, greenhouse gas mitigation potential, environment, …) make this whole topic a complex subject. This paper is primarily a descriptive research and review of literature on employment and other socio-economic aspects of bioenergy systems as drivers for implementing bioenergy projects. Due to the limited information, this paper does not provide absolute quantification on the multiplier effects of local and or national incomes of any particular country or region. The paper intends to trigger a more in-depth discussion of data gaps, potentials, opportunities and challenges. An encouraging trend is that in many countries policy makers are beginning to perceive the potential economic benefits of commercial biomass e.g. employment/earnings, regional economic gain, contribution to security of energy supply and all others.
TL;DR: In this paper, the influence of co-firing biomass with bituminous coal on ash properties has been analyzed and the general conclusion is that co-fire biomass increases the fireside slagging hazard.
Abstract: In order to show the influence of co-firing biomass with bituminous coal on ash properties, calculations of fusibility correlations have been carried out. Two Upper Silesian coals (with lower—LS and higher—HS slagging inclination) were chosen for emphasizing the influence of basic fuel. Four kinds of biomass were considered: straw, wood, dried sewage sludge and bone meal. Chemical constitutions of the mineral matter as well as the results of calculations are presented in Tables 2–5. The general conclusion is that co-firing biomass increases the fireside slagging hazard. The most difficult additional fuels are sludge and bone meal.
TL;DR: In this paper, the authors deal with the policy and planning issues for utilization of ethanol and biodiesel in automotive diesel engines in Indian context in view of environmental benefits, energy self-sufficiency and boosting of the rural economy as well as measures related to implementation and barriers.
Abstract: This paper deals the policy and planning issues for utilization of ethanol and biodiesel in automotive diesel engines in Indian context in view of environmental benefits, energy self-sufficiency and boosting of the rural economy as well as measures related to implementation and barriers. The main focus of this paper is on transport and refinery scenario, land availability for production of biodiesel and potential sources for biodiesel and ethanol. The availability of ethanol and estimations for its consumption as transport fuel are made and necessary remedial measures to increase the availability of ethanol in the country in future are suggested.
TL;DR: In this paper, the effects of tobacco seed oil methyl ester addition to diesel No. 2 on the performance and emissions of a four cycle, four cylinder turbocharged indirect injection (IDI) diesel engine were examined at both full and partial loads.
Abstract: Vegetable oils and their methyl/ethyl esters are alternative renewable fuels for compression ignition engines. Different kinds of vegetable oils and their methyl/ethyl esters have been tested in diesel engines. However, tobacco seed oil and tobacco seed oil methyl ester have not been tested in diesel engines, yet. Tobacco seed oil is a non-edible vegetable oil and a by-product of tobacco leaves production. To the author's best knowledge, this is the first study on tobacco seed oil methyl ester as a fuel in diesel engines. In this study, potential tobacco seed production throughout the world, the oil extraction process from tobacco seed and the transesterification process for biodiesel production were examined. The produced tobacco seed oil methyl ester was characterized by exposing its major properties. The effects of tobacco seed oil methyl ester addition to diesel No. 2 on the performance and emissions of a four cycle, four cylinder turbocharged indirect injection (IDI) diesel engine were examined at both full and partial loads. Experimental results showed that tobacco seed oil methyl ester can be partially substituted for the diesel fuel at most operating conditions in terms of performance parameters and emissions without any engine modification and preheating of the blends.
TL;DR: In this article, 12 clones of fast growing trees (willow and poplar) were planted in 1999 under short-rotation intensive culture (SRIC) on an abandoned farmland in southern Quebec.
Abstract: Twelve clones of fast growing trees (willow and poplar) were planted in 1999 under short-rotation intensive culture (SRIC) on an abandoned farmland in southern Quebec. The plantation was established at a density of 18,000 trees per hectare from stem cuttings and no fertilizer and irrigation were applied. Trees performances were measured at regular interval during four growing seasons. The aims of the experiment were to compare the growth, insect and disease resistance of these clones in order to select those that have good potential for use as commercial biomass energy crops in northern regions of North America. The follow up of the growing performance has shown statistically significant differences between the clones. Poplar clones registered the highest aboveground biomass yield after 4 growing seasons (from 66.48 to 72.20 tDM ha - 1 ). The best willow biomass productivity was obtained from clones SX64 (67.58 tDM ha - 1 ) and clone SX61 (62.34 tDM ha - 1 ). Only one willow clone S301 ( Salix interior × S. eriocephala ) was sensitive to leaf rust ( Melampsora spp.) and clones SVQ ( S. viminalis ) and SV1 ( S. dasyclados ) were more prone to insect attacks. The results proved that some clones of S. miyabeana and S. sachalinensis were more productive and more resistant to insect and disease damage than S. viminalis which has been widely planted in SRIC in southern Quebec since many years.
TL;DR: In this article, non-renewable energy consumption and greenhouse gas 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.
Abstract: 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 (N 2 O) 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 N 2 O 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 CO 2 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.
TL;DR: In this paper, a study was conducted to evaluate soil carbon stocks within established switchgrass stands and nearby cultivated cropland on farms throughout the northern Great Plains and northern Cornbelt.
Abstract: Switchgrass ( Panicum virgatum L.) is considered to be a valuable bioenergy crop with significant potential to sequester soil organic carbon (SOC). A study was conducted to evaluate soil carbon stocks within established switchgrass stands and nearby cultivated cropland on farms throughout the northern Great Plains and northern Cornbelt. Soil from 42 paired switchgrass/cropland sites throughout MN, ND, and SD was sampled to a depth of 120 cm and analyzed for soil carbon in depth increments of 0–5, 5–10, 10–20, 20–30, 30–60, 60–90, and 90–120 cm. SOC was greater ( P 0.1 ) in switchgrass stands than cultivated cropland at 0–5, 30–60, and 60–90 cm. Differences in SOC between switchgrass stands and cultivated cropland were especially pronounced at deeper soil depths, where treatment differences were 7.74 and 4.35 Mg ha −1 for the 30–60 and 60–90 cm depths, respectively. Greater root biomass below 30 cm in switchgrass likely contributed to trends in SOC between switchgrass stands and cultivated cropland. Switchgrass appears to be effective at storing SOC not just near the soil surface, but also at depths below 30 cm where carbon is less susceptible to mineralization and loss.
TL;DR: In this article, the authors present four case study summaries to illustrate installed commercial applications of phytoremediation, including a root-zone reactor volume with predictable pollutant removal performance, which integrates with other engineered systems to cover landfills, treat petrochemical spills in soils, intercept a soluble subsurface plume, and capture nonpoint surface sediment entrained in urban or field runoff.
Abstract: Phytoremediation (phyto) strategies employ trees, shrubs, and/or grasses for treating contaminated air, soil, or water. These strategies include buffers, vegetation filters, in situ phytoremediation plantings, and percolation controlling vegetative caps. The design parameter that separates phytoremediation from landscaping is purposefully placing and growing a root-zone reactor volume with predictable pollutant removal performance. This phyto reactor integrates with other engineered systems to cover landfills, treat petrochemical spills in soils, intercept a soluble subsurface plume, and capture non-point surface sediment entrained in urban or field runoff. There are many potential economic opportunities for biomass associated with phytoremediation, including bioenergy and traditional industrial products such as solid wood products and reconstituted products (i.e., paper, chip board, laminated beams, extruded trim). More intangibly, phyto creates environmental benefits such as soil erosion control, carbon sequestration, and wildlife habitat. Phyto also creates socio-economic benefits by diversify regional manufacturing into new products that employs local labor, thus building value-added industry. Alternative crops develop a greater diversity of products from the farmland, making the regional economy less exposed to global commodity crop price fluctuations. Thus, a strategic phyto treatment of non-point agricultural runoff would help diversify land use from annually tilled crops (corn, soybeans, wheat) into perennial, untilled tree crops. A landscape rebuilt using phyto would create diversity represented in business potential, healthier air and water, wildlife habitat, and aesthetics. Moreover, phyto provides local and current pollutant treatment. Such timely treatment of pollutants that would otherwise move to our downstream or downwind neighbors is key to the environmental justice concept. We present four case study summaries to illustrate installed commercial applications of phytoremediation.
TL;DR: In this paper, the variation in the chemical composition and energy content of aboveground components of the corn plant over time and evaluate how composition changes after grain physiological maturity is reached and the plants are weathered while undergoing further field drying.
Abstract: How to harvest and process corn stover to maximize its quality as a fuel or industrial feedstock and minimize material losses are compelling issues in the industrial utilization of corn stover. The objectives of this investigation were to evaluate the variation in the chemical composition and energy content of aboveground components of the corn plant over time and to evaluate how composition changes after grain physiological maturity is reached and the plants are weathered while undergoing further field drying. Above ground biomass distribution and composition of two almost identical corn cultivars (Pioneer 32K61 and 32K64 Bt) were studied from an estimated 2 weeks before corn kernel physiological maturity until 4 weeks after the grain had already reached a moisture content suitable for combine harvesting. Compositional analysis of corn stover fractions gathered over the course of maturation, senescence, and weathering using NIR spectroscopy showed (1) a rapid drop in soluble glucan, (2) increase in lignin, and (3) increase in xylan. By day 151 after planting, about when grain from surrounding non-test plots was harvested at about 15.5% moisture, composition of the different fractions remained fairly constant. Since product yield in fermentation-based biomass conversion processes is proportional to the structural carbohydrate content of the feedstock, timing of stover collection and the proportion of anatomical fractions collected affect the quality of corn stover as fermentation feedstock. Since the energy content of corn stover anatomical fractions is shown to remain fairly constant over time and from one plant to another (16.7–20.9 kJ g−1), insofar as combustion processes are concerned, it apparently makes little difference which part of the plant is used, or at what time the material is harvested.
TL;DR: In this paper, the authors presented a new approach in fuel characterization: the method excludes the presence of impurities, and focus on different categories of plant tissues, which made it possible to discuss the contents of ash element in a wide spectrum of fuel types.
Abstract: Woody biomass in Finland and Sweden comprises mainly four wood species: spruce, pine, birch and aspen. To study the ash, which may cause problems for the combustion device, one tree of each species were cut down and prepared for comparisons with fuel samples. Well-defined samples of wood, bark and foliage were analyzed on 11 ash-forming elements: Si, Al, Fe, Ca, Mg, Mn, Na, K, P, S and Cl. The ash content in the wood tissues (0.2–0.7%) was low compared to the ash content in the bark tissues (1.9–6.4%) and the foliage (2.4–7.7%). The woods’ content of ash-forming elements was consequently low; the highest contents were of Ca (410–1340 ppm) and K (200–1310), followed by Mg (70–290), Mn (15–240) and P (0–350). Present in the wood was also Si (50–190), S (50–200) and Cl (30–110). The bark tissues showed much higher element contents; Ca (4800–19,100 ppm) and K (1600–6400) were the dominating elements, followed by Mg (210–2400), P (210–1200), Mn (110–1100) and S (310–750), but the Cl contents (40–330) were only moderately higher in the bark than in the wood. The young foliage (shoots and deciduous leaves) had the highest K (7100–25,000 ppm), P (1600–5300) and S (1100–2600) contents of all tissues, while the shoots of spruce had the highest Cl contents (820–1360) and its needles the highest Si content (5000–11,300). This paper presented a new approach in fuel characterization: the method excludes the presence of impurities, and focus on different categories of plant tissues. This made it possible to discuss the contents of ash element in a wide spectrum of fuel-types, which are of large importance for the energy production in Finland and Sweden.
TL;DR: In this article, the authors survey the methods of integrating biomass technologies with carbon dioxide capture, and model an IGCC electric power system in detail, based on analysis and operational results of the Battelle/Future Energy Resources Corporation gasifier technology, integrating gasification, syngas conditioning, and carbon capture with a combined cycle gas turbine to generate electricity with negative net carbon emissions.
Abstract: Integration of biomass energy technologies with carbon capture and sequestration could yield useful energy products and negative net atmospheric carbon emissions. We survey the methods of integrating biomass technologies with carbon dioxide capture, and model an IGCC electric power system in detail. Our engineering process model, based on analysis and operational results of the Battelle/Future Energy Resources Corporation gasifier technology, integrates gasification, syngas conditioning, and carbon capture with a combined cycle gas turbine to generate electricity with negative net carbon emissions. Our baseline system has a net generation of 123 MW e , 28% thermal efficiency, 44% carbon capture efficiency, and specific capital cost of 1,730 $ kW e −1 . Economic analysis suggests this technology could be roughly cost competitive with more conventional methods of achieving deep reductions in CO 2 emissions from electric power. The potential to generate negative emissions could provide cost-effective emissions offsets for sources where direct mitigation is expected to be difficult, and will be increasingly important as mitigation targets become more stringent.
TL;DR: In this article, the authors discussed the importance of biomass as a source of energy in Sri Lanka and assessed the sustainable national non-plantation biomass resource potential, both direct and indirect.
Abstract: This paper discusses the importance of biomass as a source of energy in Sri Lanka and assesses the sustainable national non-plantation biomass resource potential. Different biomass sources, both direct and indirect, are considered in the analysis. The direct sources include agricultural and wood residues, animal manure, municipal solid waste and wastewater. The indirect sources include fuelwood conservation through efficiency improvements and fuelwood savings through fuel switching. The potential of each source is estimated for the base year 1997 as well as for the years 2005 and 2010. The total energy potential of these sources in 1997, 2005 and 2010 is 120 PJ, 133 PJ and 142 PJ, respectively. The corresponding electricity generation potentials are 8.34, 9.24 and 9.85 TWh, respectively for a conversion efficiency of 25%. The annual electricity demand in Sri Lanka 1997 was 4.20 TWh and the forecast values for the years 2005 and 2010 are 10.50 and 15.60 TWh respectively; this implies that the biomass sources could contribute significantly towards meeting the future electricity requirement.
TL;DR: In this article, the effect of reaction parameters such as the molar ratio of CaO to carbon in the woody biomass, reaction pressure, and reaction temperature was investigated on H 2 yield and conversion to gas.
Abstract: In H 2 production from woody biomass by steam gasification using CaO as a CO 2 sorbent, the effect of reaction parameters such as the molar ratio of CaO to carbon in the woody biomass ( [ Ca ] / [ C ] ) , reaction pressure, and reaction temperature was investigated on H 2 yield and conversion to gas. In the absence of CaO, the product gas contained CO 2 . On the other hand, in the presence of CaO ( [ Ca ] / [ C ] = 1 , 2 , and 4), no CO 2 was detected in the product gas. At a [ Ca ] / [ C ] of 2, the maximum yield of H 2 was obtained. The H 2 yield and conversion to gas were largely dependent on the reaction pressure, and exhibited the maximum value at 0.6 MPa . It is noteworthy that H 2 was obtained from woody biomass at a much lower pressure compared to other carbonaceous materials such as coal ( > 12 MPa ) and heavy oil ( > 4.2 MPa ) in steam gasification using a CO 2 sorbent. H 2 yield increased with increasing reaction temperature. Woody biomass is the one of the most appropriate carbonaceous materials in H 2 production by steam gasification using CaO as a CO 2 sorbent, taking the reaction pressure into account.
TL;DR: In this article, the effect of woody biomass components on air-steam gasification was investigated using the downdraft fixed-bed gasifier at 1173 K and at atmospheric pressure.
Abstract: The effect of woody biomass components on air-steam gasification was investigated using the downdraft fixed-bed gasifier at 1173 K and at atmospheric pressure. Cellulose, xylan, and lignin as model compounds of woody biomass components, and Japanese oak and Japanese red pine bark as woody biomass were employed as feedstock. The gasification conversions in cellulose, xylan, and lignin were 97.9%, 92.2%, and 52.8% on a carbon basis, respectively. In each run, the main components of the gas phase were CO, CO 2 , H 2 , and CH 4 . The product gas composition in cellulose was 35.5 mol % CO, 27.0 mol % CO 2 , and 28.7 mol % H 2 , and the CO composition was higher than the CO 2 or H 2 compositions, which was similar to that in the Japanese oak, of which the main component was cellulose. In contrast, the product gas compositions in xylan and lignin were approximately 25 mol % CO, 36 mol % CO 2 , and 32 mol % H 2 , and the CO composition was lower than the CO 2 or H 2 compositions, which were similar to those in Japanese red pine bark, of which the main component was lignin. These results suggest that the fundamental information obtained in the gasification of each component could possibly be used to predict the composition of product gas generated in air-steam gasification of woody biomass.
TL;DR: A GIS model is proposed for land-suitability assessment of potential energy systems featuring an AD coupled with an energy generator, capable of providing a broad-scale and multidimensional view on the potential bio-energy systems development in the area of study.
Abstract: There is growing interest in installing anaerobic digesters (ADs) on farms to use animal wastes as a biomass resource for both economic value and environmental benefit. This potential expansion prompts the need for land suitability assessment. In this paper, a GIS model is proposed for land-suitability assessment of potential energy systems featuring an AD coupled with an energy generator. A variety of environmental and social constraints, as well as economic factors are integrated in the model to help determine the optimal sites for installing such systems. The analytic hierarchy process (AHP) method is employed to estimate the factors’ weights in order to establish their relative importance in site selection. The model is then applied to Tompkins County, New York as a case study for demonstration. A siting suitability map was produced to identify those areas that are most suitable for distributed bio-energy systems using dairy manure. The results showed that this GIS-based model, by integrating both spatial data and non-spatial information, was capable of providing a broad-scale and multidimensional view on the potential bio-energy systems development in the area of study to account for environmental and social constraints as well as economic factors. The model can be modified for evaluating other biomass resources.
TL;DR: In this article, the potential of energy from crop residues, animal manure, waste water, industrial waste water and biomass fuels that can be conserved for other applications through efficiency improvement is discussed.
Abstract: In India, fuelwood, crop residues and animal manure are the dominant biomass fuels, which are mostly used in the rural areas, at very low efficiencies. Industrial and municipal (urban) residues such as waste water, municipal solid wastes (MSW), and crop residues such as rice husk and bagasse can also be used for energy generation. In this paper, the potential of energy from crop residues, animal manure, MSW,industrial waste water and biomass fuels that can be conserved for other applications through efficiency improvement is discussed. The total potential of energy from these sources in 1997 is estimated to be equivalent to 5.14 EJ, which amounts to a little more than a-third of the total fossil fuel use in India. The energy potential in 2010 is estimated to be about 8.26 EJ.
TL;DR: In this paper, the role of particle size and pile height on the processes which occur during storage and how it affects fuel quality was evaluated with respect to moisture content, heating value, particle size distribution, and ash content.
Abstract: Biomass from short rotation forestry can provide a valuable energy source but maintaining the quality of the material during handling and storage is challenging The relatively young plant material is highly prone to microbial degradation and can consequently suffer changes in fuel quality The aim of this work is to evaluate the role of particle size and pile height on the processes which occur during storage and how it affects fuel quality Fresh willow shoots ( Salix viminalis) were comminuted into chips and chunk wood (nominal size 22–45 mm), stored in 3 and 6 m high piles for 2 and 3 months respectively Results showed that the four piles exhibited different behaviour Temperature development was rapid and prominent in the chipped willow particularly in the 6 m high pile In the chunk woodpiles, temperature rise was very slow and became notably higher than ambient temperature only after 2 months of storage in the 6 m high pile The effect of storage on fuel quality was evaluated with respect to moisture content, heating value, particle size distribution, and ash content In general, salix chips had a relatively lower moisture content and energy value than chunk wood by the end of storage Evaluation of fungal activity during storage showed that marked increase in spore counts was closely associated with heat development
TL;DR: In this article, the availability of logging residues was analyzed by means of resource and demand approach in order to identify the most suitable regions with focus on increasing the forest fuel usage, and the analysis included availability comparisons between power plant sites and resource allocation in a least-cost manner according to supply cost.
Abstract: Finland has large forest fuel resources. However, the use of forest fuels for energy production has been low, except for small-scale use in heating. According to national action plans and programs related to promotion of biofuels, the utilization of such resources will be multiplied over the next few years. The most significant part of this growth will be based on the utilization of forest fuels, produced from logging residues of regeneration fellings, in industrial and municipal power and heating plants. Availability of logging residues was analyzed by means of resource and demand approach in order to identify the most suitable regions with focus on increasing the forest fuel usage. The analysis included availability comparisons between power plant sites and resource allocation in a least-cost manner according to supply cost, and between a predefined power plant structure under given demand and supply constraints. Spatial analysis of worksite factors and regional geographies was carried out using the Graphics Information System-model (GIS-model) environment via geoprocessing and cartographic modeling tools. According to the site-specific analysis, the supply potential of different locations can differ multifold. However, due to technical and economical reasons of the fuel supply and dense power plant infrastructure, the supply potential is limited to plant level. Therefore, the potential and supply–cost calculations depend on site-specific matters, where regional characteristics of resources and infrastructure should be taken into consideration, e.g., by using a GIS-modeling approach constructed in this study.
TL;DR: In this article, the use of agricultural residue in Japan as an energy resource, based on the amounts produced and availability, was discussed, and the authors evaluated the size, cost, and CO 2 emission for power generation.
Abstract: This paper discusses the use of agricultural residue in Japan as an energy resource, based on the amounts produced and availability. The main agricultural residues in Japan are rice straw and rice husk. Based on a scenario wherein these residues are collected as is the rice product, we evaluate the size, cost, and CO 2 emission for power generation. Rice residue has a production potential of 12 Mt-dry year −1 , and 1.7 kt of rice straw is collected for each storage location. As this is too small an amount even for the smallest scale of power plant available, 2-month operation per year is assumed. Assuming a steam boiler and turbine with an efficiency of 7%, power generation from rice straw biomass can supply 3.8 billion(kW)h of electricity per year, or 0.47% of the total electricity demand in Japan. The electricity generated from this source costs as much as 25 JPY (kW h) −1 (0.21 US$ (kW h) −1 , 1 US$=120 JPY), more than double the current price of electricity. With heat recovery at 80% efficiency, the simultaneous heat supplied via cogeneration reaches 10% of that supplied by heavy oil in Japan. Further cost incentives will be required if the rice residue utilization is to be introduced. It will also be important to develop effective technologies to achieve high efficiency even in small-scale processes. If Japanese technologies enable the effective use of agricultural residue abroad as a result of Japanese effort from the years after 2010, the resulting reduction of greenhouse gas emission can be counted under the framework of the Kyoto Protocol.