A decision support system for planning biomass-based energy production

Environmental decision support systems (EDSS) are recognized as valuable tools for environmental planning and management. In this paper, a geographic information system (GIS)-based EDSS for the optimal planning of forest biomass use for energy production is presented. A user-friendly interface allows the creation of Scenarios and the running of the developed decision and environmental models. In particular, the optimization model regards decisions over a long-term period (e.g. years) and includes decision variables related to plant locations, conversion processes (pyrolisis, gasification, combustion), harvested biomass. Moreover, different energy products and different definitions of the harvesting and pre-treatment operations are taken into account. The correct management of the forest is considered through specific constraints, security factors, and procedures for parcel selection. The EDSS features and capabilities are described in detail, with specific reference to a case study. Discussion and further research are reported.     

A decision model for energy resource selection in China

This paper evaluates coal, petroleum, natural gas, nuclear energy and renewable energy resources as energy alternatives for China through use of a hierarchical decision model. The results indicate that although coal is still the major preferred energy alternative, it is followed closely by renewable energy. The sensitivity analysis indicates that the most critical criterion for energy selection is the current energy infrastructure. A hierarchical decision model is used, and expert judgments are quantified, to evaluate the alternatives. Criteria used for the evaluations are availability, current energy infrastructure, price, safety, environmental impacts and social impacts.     

Cotton logistics as a model for a biomass transportation system

To reach the US Department of Energy's goal of replacing 30% of current petroleum consumption by biomass and its products by year 2030, various systems capable of harvesting, storing and transporting biomass efficiently, at a low cost, need to be designed. The transportation system of a cotton gin, which shares several key components with a biomass transportation system, was simulated using a discrete event simulation procedure, to determine the operating parameters under various management practices.

The cotton module transportation system, when operating under a FIFO management plan, was found to operate at 77% utilization factor, while the actual ginning process operated at 69%. Two greedy algorithm-based management policies were simulated, which increased the gin operational factor to 100%, but doing so required an increase in gin inventory level. A knapsack model, with travel times, was constructed and solved to obtain the lower bound for the transportation system. The significance of these operating parameters and their links to a biomass transportation system are presented.

Using the new management strategies, the utilization factor for the transportation system was increased to 99%. To achieve this improvement, the transportation manager must know where all modules are located and have the ability to dispatch a hauler to any location.     

Input-output analysis of energy requirements for short rotation, intensive culture, woody biomass

A production model for short rotation, intensive culture (SRIC) plantations was developed to determine the energy and financial costs of woody biomass. The model was based on hybrid poplars planted on good quality agricultural sites at a density of 2100 cuttings ha⁻¹, with average annual growth forecast at 16 metric tonne, oven dry (Mg(OD)). Energy and financial analyses showed preharvest costs of 4381 megajoules (MJ) Mg⁻¹ (OD) and $16 (U.S.) Mg⁻¹ (OD). Harvesting and transportation requirements increased the total costs to 6130 MJ Mg⁻¹ (OD) and $39 Mg⁻¹ (OD) for the delivered material. On an energy cost basis, the principal input was land, whereas on a financial basis, costs were more uniformly distributed among equipment, land, labor, and materials and fuel.     

Identifying agricultural sites for biomass energy production in Minnesota

This research examines the potential of producing hybrid poplar on location specific marginal agricultural lands in Minnesota. It is assumed that all poplar production would be used to meet biomass energy requirements for two potential 100 MW power plants located in Alexandria and Granite Falls, Minnesota. The delivered fuelwood costs for each power plant are calculated using a cost minimization model. In addition to traditional production and harvesting costs, the model also incorporates landowners opportunity cost of fuelwood production as well as the actual transportation costs associated with supply from each individual analysis area to each power plant. The inclusion of any analysis area as a potential fuelwood supplier is greatly dependent on the interaction and combination of variables such as the opportunity cost, yield rates, and the distance from the power plants. The results show that approximately 40×10³ hectares of land capable of producing about 3.2×10[6] dry Mg of wood would be required to fuel each power plant for a 10 year planning period. The average present value costs of delivered (to the plant gate) fuelwood is about $32 dry Mg⁻¹ for Alexandria and $37 dry Mg⁻¹ for Granite Falls.     

Harvesting operations and energetics of tall grasses for biomass energy production: A case study

The U.S.A. imports about 50% of its energy needs while Florida imports about 85%. Among the renewable energy sources available, biomass appears promising especially in the southeast which includes Florida because of a favorable environment for production and the available methods to convert biomass to energy. Optimal production of biomass requires the identification and management of high yielding persistent perennial cultivars. Elephantgrass (Pennisetum purpureum Schum.) and energycane (Saccharum spontaneum L.) are two tall grasses that meet these requirements. To optimize the supply of convertible biomass, suitable methods of harvesting the crop must be available. The purpose of this research was to study the feasibility and energetics of harvesting, drying, and baling tall grasses with conventional farm machinery.

A Mathews rotary scythe and a New Holland 849 Auto Wrap large round baler were determined to provide a practical harvesting system for baled biomass averaging 15–27 Mg ha⁻¹. The rotary scythe can be used for harvesting and fluffing or turning a windrow over to expedite drying. This harvesting system requires about 3 kg diesel fuel Mg⁻¹ dry biomass (DB), 25 min of time Mg⁻¹ DB, and a cost of about $10 to 12 Mg⁻¹ DB. Energy requirements of harvesting operations would be about 300–375 MJ Mg⁻¹ DB, and primary energy requirements for production and harvesting are about 1100–1500 MJ Mg⁻¹ DB. For each unit of fossil fuel invested in the total production and harvesting system, 12–15 units would be returned in biomass.     

Electricty generation from woody biomass fuels compared with other renewable energy options

The future New Zealand biomass resource from exotic plantation forest arisings could supply 970 GWh/year by the year 2002. Associated wood processing residues could supply 280 GWh/year. Purpose grown fuelwood plantations could supply 2060 GWh/year with potential to rise to 10,000 GWh/year by 2012.Currently the annual electricity demand is around 30,000 GWh 70% of which is generated by hydro power. Natural gas, a resource with estimated reserves of only approximately 14 years currently supplies 25% of generating capacity. This paper describes how part replacement of gas by biomass could be a feasible proposition for the future.Life cycle cost analyses showed electricity could be generated from arisings for (US)4.8–6 c/kWh; from residues for (US)2.4–4.8 c/kWh; and from plantations for (US)4.8–7.2 c/kWh. For comparison the current retail electricity price is around (US)4–5.5 c/kWh and estimates for wind power generation range from (US)5–10 c/kWh. Future hydropower schemes will generate power between (US)4–9 c/kWh depending on site suitability.     

Agricultural biomass production is an energy option for the future

The production of agricultural biomass and its exploitation for energy purposes can contribute to alleviate several problems, such as the dependence on import of energy products, the production of food surpluses, the pollution provoked by the use of fossil fuels, the abandonment of land by farmers and the connected urbanization. Biomass is not at the moment competitive with mineral oil, but, taking into account also indirect costs and giving a value to the aforementioned advantages, public authorities at national and international level can spur its production and use by incentives of different nature. On long term perspective, technological innovation can improve the cost effectiveness of biomass production. For this purpose a new cycle of plant domestication is needed, in order to develop new plant genera, species or varieties yielding quantities of biomass higher than plants now cultivated for food production. The strategies and objectives of plant breeding for this domestication cycle are briefly discussed. Two specific cases of use of agricultural biomass for energy production can be considered as more feasible in the next future: the production of biodiesel from vegetable oil and the production of electricity from ligno-cellulosic biomass. Both possibilities are discussed from a technical and from an economical point of view.     

Goal programming model for sustainable electricity production from biomass

In this paper, we present a goal programming model for block level energy planning in order to make a block self‐sufficient in electricity consumption, which includes the commercial energy consumption goal, the goal of generating electricity from biomass and food production goals with linear constraints on the available sources such as human power, animal power, tractor power, land area and on the requirement of the block such as cooking energy, lighting energy and energy for other operations, such as fodder for animal population. We try to achieve these goals through proper allocation of land for different crops. After reformulating the developed goal programming model into a linear programming format, we use the HYPER LINDO software package to solve it in a Pentium‐based IBM‐PC compatible computer system. The developed model is solved for a typical Indian block, namely Nilakkottai Block in Tamil Nadu, India. The model solution shows that the goal of generating electricity from biomass is achieved, the commercial energy consumption goal and pulses requirement goal are under‐achieved and the sugar requirement goal is over‐achieved. Furthermore, the cereal, vegetable and oilseed production goals are achieved. Copyright © 2000 John Wiley & Sons, Ltd.     

Estimation of woody biomass production from a short-rotation bio-energy system in semi-arid Australia

Short, 3–5 year, rotations of trees have been proposed as a method of regaining hydrological control of dryland farming systems (300–600 mm annual rainfall) in southern Australia and thus alleviating salinization of land and water. At the termination of the rotation, the trees will be removed and used as a bioenergy feedstock. In the absence of any tree growth data in this region, allometric relationships were developed for three prospective short-rotation species (Eucalyptus globulus, Eucalyptus occidentalis and Pinus radiata), for 3-year-old trees, at a site with a mean annual rainfall of 365 mm. Equations that related stem diameter over bark at 10 cm (D₁₀) and tree height (ht) to total tree biomass (above and below ground), leaves, stems (stemwood and bark) and roots were developed, by combining data from different planting densities (500, 1000, 2000 and 4000 stem ha⁻¹) and landscape positions (upper-slope, mid-slope and lower-slope).Mean oven-dry yields of the three species, in the high planting density treatment were not significantly different and ranged from 12 to 14 t ha⁻¹ (3 years)⁻¹. There were consistent increases in biomass yield with planting density, with this generally being greatest with the 4000 stem ha⁻¹ treatment. There were marked differences in productivity with slope position. For E. globulus and E. occidentalis the best yields were obtained in lower landscape positions with initial planting densities of 4000 stem ha⁻¹, with 16.6 and 22.2 t ha⁻¹ (3 years)⁻¹, total biomass produced, respectively. The best yield of P. radiata was 15.4 t ha⁻¹ (3 years)⁻¹ from an initial planting density of 4000 stem ha⁻¹ in an upper landscape position. These differences partly reflected site hydrology, with water accumulating in downslope positions. Partitioning of tree components was variable between species, with root:shoot (R:S) ratio being significantly (P<0.0001) higher for E. occidentalis (0.5) compared with the other two species (0.3). Results suggest that biomass productivity can be optimized in this region by using high initial planting densities and recognizing the interaction of different species with site hydrology.     

中国油菜秸秆资源的生物质能源利用潜力评价

文章利用中国各省(市)的农作物种植数据,估算长江流域油菜优势种植区域的冬闲土地面积,并评估油菜秸秆的产量和能源产品的生产潜力。研究发现:中国长江流域冬闲土地面积为1 648万hm2,可利用面积为494万hm2;2013年中国油菜秸秆和冬闲土地油菜秸秆的可收集量分别为3 817万t和2 483万t,总量可达6 300万t;油菜秸秆生物炭或生物油的总生产潜力分别为2 079万t或2 646万t,折合标准煤量为1 746万t或1 826万t;在利用50%油菜秸秆资源的情况下,生物油替代能源消费量的潜力达到913万t标准煤。中国的油菜秸秆资源十分丰富,且分布集中,其能源化利用具有规模优势,值得重视和发展。     

Development of renewable biomass energy by catalytic gasification: Syngas production for environmental management

Gasification is a process in which biomass is decomposed into small quantities of solid char and ash and large quantities of gaseous products in the presence of one or more fluidizing agents. In this paper, a lab scale fluidized bed gasifier was used to explore the effects of different kinds of calcined dolomites (CD-1, CD-2, and CD-3) on tar conversion and composition during air-steam gasification of biomass. Results showed that all dolomites have a good performance in terms of tar reduction but CD-2 is more reactive than two other dolomites with respect to tar destruction. When the temperature was lower than 850^?C, conversion of tar was relatively low; however, with temperature increasing further (>850 ^?C), tar conversion was greatly enhanced.     

A thermoeconomic analysis of biomass energy for trigeneration

The principal objective of this study is to formulate a calculation process, based on the second law of exergy, for evaluating the thermoeconomic potential of a steam-turbine plant for trigeneration. The plant employs biomass, namely, waste wood as its energy source. Four different plant configurations are presented and assessed. ‘Their cost effectiveness is evaluated with varying economic and operating parameters’, because only the fuel price and electricity price are varied. In case 1, high pressure superheated steam generated is supplied to meet the demand for process heat as well as chilled water production in an absorption chiller. In cases 2 and 3, steam is extracted at appropriate stages of the turbine and supplied to meet the demand for process heat and chilled water production in an absorption chiller. Steam generated in case 2 produces sufficient power to meet internal demands while case 3 generates excess electricity for sale back to the utility. In case 4, low pressure saturated steam is generated to meet the demand for process heat and electricity is bought from the utilities, including those used to power an electric vapour-compression chiller. For all cases, it was found that exergy destruction is most extensive in the furnace, amounting to nearly 60%. Exergy destruction in the steam drum is the next most extensive ranging from 11% to 16%. It was also observed that the overall production cost decreases with steam pressure and increases with steam temperature.     

Conceptual net energy output for biofuel production from lignocellulosic biomass through biorefining

There is a lack of comprehensive information in the retrievable literature on pilot scale process and energy data using promising process technologies and commercially scalable and available capital equipment for lignocellulosic biomass biorefining. This study conducted a comprehensive review of the energy efficiency of selected sugar platform biorefinery process concepts for biofuel production from lignocelluloses. The process data from approximately a dozen studies that represent state-of-the-art in cellulosic biofuel production concepts, along with literature energy input data for agriculture operations, were analyzed to provide estimates of net energy production. It was found that proper allocation of energy input for fertilizer and pesticides to lignocellulosic biomass and major agriculture or forestry products, such as corn and lumber in corn farming and lumber plantations, respectively, were critical. The significant discrepancies in literature data suggest studies are needed to determine energy inputs for fuel in farming and farm machinery. Increasing solids loading in pretreatment to at least 25% is critical to reducing energy input in a biorefinery. Post thermo-chemical pretreatment size reduction approach should be adopted for energy efficient woody biomass processing. When appropriate pretreatment technologies are used, woody biomass can be processed as efficiently as herbaceous biomass and agricultural residues. Net energy output for cellulosic ethanol was estimated to range approximately from −500–2000 MJ/ton biomass (HHV base); indicating that the energy input/output ratio is approximately 1:1 for cellulosic ethanol. However, net energy can reach approximately 4000–7000 MJ/ton of biomass when energy from lignin is included.     

Current status and prospects of biomass resources for energy production in Lithuania

Basic biomass sources in Lithuania are comprised of wood, straw, biofuel and biogas. The current status and the problems from using biomass for energy production in Lithuania are analyzed. The possibility of utilizing wood waste, firewood, straw and biogas for energy is evaluated. Forest comprises about 2.05 Mha or 31.3% of Lithuanian land area. About 4.3 million m³ solid volume of wood per year can be used for fuel (843 ktoe). Wood as fuel is used directly or in processed form (briquettes, pellets and chips).Agriculture produces approximately 1.5–2.0 million tons of straw each year for animal feed, litter and olericulture. Around 30–40% (130 ktoe) could be used as fuel for energy production. Boiler houses for combusting the straw have increased and now comprise about 7 MW. Straw is also used for heating private houses.Sources for biogas production include sludge from water cleaning equipment, animal manure and organic waste in food processing companies. Total volume of operating bioreactors comprises about 24 000 m³, and annual production of biogas is 6.3 million m³ per year (3.4 ktoe). By year 2010 the total volume of bioreactors will increase to 35 000 m³ and about 50 000 m³ by 2040.In Lithuania biodiesel and bioethanol are mainly used in blending with conventional fuel. Following the requirements of the European Union (EU), 2% of total consumed fuel per year is to be produced in 2005. By 2010 biofuel should comprise not less than 5.75% of all fuel existing in the market.     

A preliminary analysis of the biomass energy production potential in Africa in 2025 considering projected land needs for food production

This paper provides a preliminary examination of present and projected land use in Africa to estimate the potential availability of land in 2025 for use in producing biomass energy. Fifty countries are included in the analysis. Future cropland requirements are projected on the basis of average African cereal crop yield improvements since 1972, and minimum nutritional requirements are assumed to be met in 2025 without increasing imports above present absolute levels. Cropland, natural forests and other wilderness areas are excluded from consideration for biomass energy use. Woody biomass energy yields are estimated on the basis of nationally averaged precipitation, using a yield-precipitation correlation for commercial eucalyptus plantations in Brazil. The total African bioenergy production potential in 2025 is estimated to be about 18 EJ per year for a set of baseline assumptions that includes planting only 10% of the available non-crop, non-forest, non-wilderness area with biomass energy crops. A preliminary cost assessment suggests that much of this biomass could be produced for $1–2 GJ⁻¹. A number of uncertainties in the modelling assumptions are examined through a sensitivity analysis. Despite limitations in the model used here, one robust conclusion is that Africa as a whole has a significant biophysical potential for producing biomass energy. This result suggests that more detailed country and sub-country level assessments would be worthwhile to understand better the practical prospects for future biomass energy production in Africa.     

Guidelines for harvesting forest biomass for energy: A synthesis of environmental considerations

Interest in the utilization of forest biomass for energy is growing. A search into existing forest biomass harvesting and regeneration guidelines was carried out to identify how biomass energy can be environmentally sustainable. Findings have shown that there are only a few guidelines that specifically address harvesting and regenerating biomass for bioenergy or other bio-based products. Of these few, there are guidelines developed for dedicated energy plantations such as the Scottish Agricultural College guidelines, as well as some Finnish and Swedish guidelines recommending management practices for both timber and biomass extraction. Most of the existing small woody material guidelines emphasize the retention, disposal, redistribution, burning and mulching of biomass material on-site in a more detailed manner than forest and timber management guidelines. This study synthesizes and classifies existing biomass-related guidelines based on an in-depth literature review of existing guidelines in Europe and North America involved with biomass energy harvesting. Biomass guidelines are classified according to those applicable to systems producing biomass commercially for energy versus those that are applicable to systems managing this material for non-commercial purposes. Biomass guidelines are analyzed with respect to how they address issues of sustainability related to soil, water and habitat. Recommendations are offered for developing guidelines for biomass harvesting.     

A regional decision support system for onsite renewable hydrogen production from solar and wind energy sources

Hydrogen technologies driven by renewable energy sources (RES) represent an attractive energy solution to ensure environmental sustainability. In this paper, a decision support system for the hydrogen exploitation is presented, focusing on some specific planning aspects. In particular, the planning aspects regard the selection of locations with high hydrogen production mainly based on the use of solar and wind energy sources. Four modules were considered namely, the evaluation of the wind and solar potentials, the analysis of the hydrogen potential, the development of a regional decision support module and a last module that regards the modelling of a hybrid onsite hydrogen production system. The overall approach was applied to a specific case study in Liguria region, in the north of Italy.     

A lifecycle-based success framework for grid-connected biomass energy projects

This paper presents a new framework to help assessing the success and its drivers of biomass energy projects. Empirical validation of the framework using data collected from operating grid-connected biomass energy plants in Thailand indicates that competencies of developer and project team members in designing biomass energy plants and conducting environment impact assessment (EIA) are significant factors for the success of the project development phase. In the construction phase, effective coordination, consultation and communication among the project team and the contractors emerge as the most significant success factors, while a competent management and O&M team is found critical to success during the operation phase. External factors such as the presence of supportive legislative, political and regulatory framework are found most instrumental for achieving overall project success. The framework demonstrates the dynamic linkage of project management success in successive lifecycle stages and phases, and thus can be used to evaluate and forecast the likelihood of success of biomass energy projects progressively over their lifecycle.