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1.
《Biomass & bioenergy》2007,31(8):535-542
In this study, the effect of emission trade on the development of the wood fuel market and on the balance of the demand and supply of wood fuels in Finland was evaluated. The demand for wood fuels was estimated to double by the year 2010 to almost 50 TWh, of which 17 TWh can be forest chips. In 2010, the supply potential of by-products was estimated to be 28 TWh, of which 11 TWh was marketable outside the internal use of the forest industry. Correspondingly, the theoretical potential of forest chips was estimated to be 51 TWh and the techno-economical potential 24 TWh, which made up the potential market supply. As a result of the regional optimization model, the energy use of wood fuels was 33 TWh, which was 68% of the potential demand in the emission trade situation. Regionally, the potential demand for wood fuels for energy use was higher than the supply in all provinces.  相似文献   

2.
《Biomass & bioenergy》2006,30(4):281-288
Renewable energy sources play an important role in the Finnish energy and climate strategies which are implemented partly through the Action Plan for Renewable Energy Sources. Enhancement of wood energy plays a key role in the plan. A special emphasis is given to forest chips produced from small-sized trees from early thinnings and above-ground and below-ground residual biomass from regeneration cuttings. The production goal of forest chips is 5 million m3 solid (10 TWh) in 2010. The use of forest chips is promoted by means of environmental taxes, financial aid for investments, and financial support for research, development and commercialization of technology. In 2002, altogether 365 heating and power plants larger than 0.4 MW used forest chips. The total consumption was 1.7 million m3, the use of small houses and farms included. The growth of use is presently about 350 000 m3 per annum, but reaching the official goal will require an annual growth of 400 000 m3 during this decade.The consumption of roundwood per capita, 15 m3 per annum, is in Finland 20 times as high as the average consumption of the EU countries, respectively. Consequently, residual forest biomass is abundantly available. The capacity of heating and power plants to use forest chips is large enough to meet the goal. However, users require competitive chip prices, good quality control of fuel and reliable supply chains, and new efficient procurement systems are being developed. The paper deals with the drivers of this development: support measures of the Government; strong support to research, development and commercialization of forest chip production from the National Technology Agency Tekes; advanced infrastructure for the procurement of timber for the forest industries; positive attitude and active participation of the forest industries; the active role of leading forest machine and boiler manufacturers, and the possibility to cofire wood and peat fuels in large fluidized bed boilers so as to secure the availability of fuel in all conditions, stabilize the moisture content of fuel and reduce the emissions from combustion.  相似文献   

3.
Recent decades have seen a strong increase in bioenergy utilization in Sweden, from 52 TWh in 1983 to 128 TWh in 2013. Much of this increase has been achieved by replacing fossil fuels with different forms of bioenergy in district heating. Increased use of bioenergy is generally seen as key to reducing fossil fuel consumption and greenhouse gas emissions and improving energy security.However, replacing fossil fuels with solid biomass fuels in stationary heat and power generation entails significantly more complicated fuel supply logistics, with geographically scattered material associated with storage difficulties and low energy density. Given these risks and challenges and the key role of biomass-based district heating in the Swedish energy system, disturbances in fuel supply to district heating could potentially be an energy security issue.Through literature studies and interviews with employees at 18 district heating plants, we mapped present and future risks and risk management strategies in district heating supply in the Mälardalen region, south-east Sweden. We found that although small disturbances to fuel supply are not uncommon, the likelihood of heat supply failures due to fuel supply problems is low. Risk awareness is generally high among fuel supply managers, with widespread use of multilevel redundancies and diversification as key risk management strategies. However, fuel supply to plants is highly dependent on functioning truck transport and, consequently, availability of diesel fuel for trucks. Risk management can be strengthened further by implementation of forward-looking risk assessments that are less reliant on past experiences.  相似文献   

4.
Michal Touš  Martin Pavlas 《Energy》2011,36(8):4654-4662
Fossil fuels such as coal still dominate in current energy production plants. However, due to their large carbon footprint caused by combustion, rising prices and the unclear an increased interest in renewable and alternative fuels is observable. By 2020, renewable energy should account for 20% of the EU’s final energy consumption in order to reduce the negative impacts of the utilization of fossil fuels. Biomass-based fuels contribute to this effort.The optimization approach introduced in this article supports sustainable and financially feasible biomass integration into the existing large energy producing system with combined heat and power (CHP) production. The objective is to identify optimal conditions (optimal amount of burned fuels with respect to energy demands and energy flows through key components) with regard to maximum annual financial profit.The general mathematical model of a CHP plant utilizing more types of fuels is introduced and an optimization problem is formulated. The approach application is demonstrated on a case study involving existing CHP plant co-firing coal and biomass. The optimization problem is implemented and solved in GAMS (General Algebraic Modeling System). A sensitivity analysis of crucial parameters is performed and the results are presented and discussed.  相似文献   

5.
The increasing use of bioenergy has resulted in a growing demand for long-distance transportation of energy wood. For both biofuels and traditional forest products, the importance of energy efficiency and rail use is growing. A GIS-based model for energy wood supply chains was created and used to simulate the costs for several supply chains in a study area in eastern Finland. Cost curves of ten supply chains for logging residues and full trees based on roadside, terminal and end-facility chipping were analyzed. The average procurement costs from forest to roadside storage were included. Railway transportation was compared to the most commonly used truck transportation options in long-distance transport. The potential for the development of supply chains was analyzed using a sensitivity analysis of 11 modified supply chain scenarios.For distances shorter than 60 km, truck transportation of loose residues and end-facility comminution was the most cost-competitive chain. Over longer distances, roadside chipping with chip truck transportation was the most cost-efficient option. When the transportation distance went from 135 to 165 km, depending on the fuel source, train-based transportation offered the lowest costs. The most cost-competitive alternative for long-distance transport included a combination of roadside chipping, truck transportation to the terminal and train transportation to the plant. Due to the low payload, the energy wood bundle chain with train transportation was not cost-competitive. Reduction of maximum truck weight increased the relative competitiveness of loose residue chains and train-based transportation, while reduction of fuel moisture increased competitiveness, especially of chip trucks.  相似文献   

6.
《Biomass & bioenergy》2007,31(10):739-746
This paper examines the possibilities of increasing the use of wood from private forests in Lithuania for bioenergy purposes. Potential wood fuel supply and consumption were investigated using a literature review and analysis of statistical data. Costs of wood chips production were calculated applying economic simulation. The analysis showed that 0.6 Mm3 (1.2 TWh) of firewood is produced and about 0.3 Mm3 (0.6 TWh) of forest logging residues could be used annually for fuel in private forests. The available volume will increase in coming decades. In total, Lithuanian households had increased wood fuel consumption by five times during 10 years and exceeded 2.3 Mm3 (4.6 TWh) in 2003. Firewood production for home consumption is one of the most important forest owners’ objectives.The cost of forest chips varied from 19 to 36 euro m−3 in pre-commercial thinnings and from 20 to 28 euro m−3 in final thinnings. The lack of specific policies supporting the use of natural resources is causing a lack of incentive to increase the use of local fuels.  相似文献   

7.
Teijo Palander 《Energy》2011,36(9):5579-5590
The Finnish energy industry is subject to policy decisions regarding renewable energy production and energy efficiency. Conventional electricity generation has environmental side-effects that may cause global warming. Renewable fuels are superior because they offer near-zero net emissions.In this study, I investigated a heating mill’s ability to generate electricity from forest fuels in southern Finland on a 1-year strategic decision-making horizon. I solved the electricity generation problem using optimization of the energy products and fuel mixtures based on energy efficiency and forest technology. The decision environment was complicated by the sequence-dependent procurement chains for forest fuels. The optimal product and fuel mixtures were selected by minimizing procurement costs, maximizing production revenues, and minimizing energy losses.The combinatorial complexity of the problem required the use of adaptive techniques to solve a multiple-objective linear programming system with industrial relevance. I discuss the properties of the decision-support system and methodology and illustrate pricing of electricity generation based on real industrial data. The electricity-generation, -purchase, and -sales decisions are made based on a comprehensive technical and economic analysis that accounts for procurement of local forest fuels in a holistic supply chain model.  相似文献   

8.
In this study we estimate the effects of climate change on forest production in north-central Sweden, as well as the potential climate change mitigation feedback effects of the resulting increased carbon stock and forest product use. Our results show that an average regional temperature rise of 4 °C over the next 100 years may increase annual forest production by 33% and potential annual harvest by 32%, compared to a reference case without climate change. This increased biomass production, if used to substitute fossil fuels and energy-intensive materials, can result in a significant net carbon emission reduction. We find that carbon stock in forest biomass, forest soils, and wood products also increase, but this effect is less significant than biomass substitution. A total net reduction in carbon emissions of up to 104 Tg of carbon can occur over 100 years, depending on harvest level and reference fossil fuel.  相似文献   

9.
The focus of the study was on examining the preparations of Finnish CHP plants for a domestic fuel crisis. National supply security has become topical as the use of domestic fuels, especially peat and wood fuels, has increased over the past decade and temporary regional shortages of domestic fuels have occurred. The study utilised a questionnaire targeting the largest domestic fuel users producing district heating and electricity. The response rate was high, reflecting the importance attached to the subject. The most significant challenges in peat fuel and wood fuel supply security were found to be the time-consuming environmental permit processes for peatlands entering energy use, lack of wood fuel terminals, and the currently unpredictable taxation and subsidy policy. General operation conditions should be improved for domestic fuels' use, and continuity of domestic labour and fuel production must be guaranteed.  相似文献   

10.
A hybrid plant producing combined heat and power (CHP) from biomass by use of a two-stage gasification concept, solid oxide fuel cells (SOFC) and a micro gas turbine was considered for optimization. The hybrid plant represents a sustainable and efficient alternative to conventional decentralized CHP plants. A clean product gas was produced by the demonstrated two-stage gasifier, thus only simple gas conditioning was necessary prior to the SOFC stack. The plant was investigated by thermodynamic modeling combining zero-dimensional component models into complete system-level models. Energy and exergy analyses were applied. Focus in this optimization study was heat management, and the optimization efforts resulted in a substantial gain of approximately 6% in the electrical efficiency of the plant. The optimized hybrid plant produced approximately 290 kWe at an electrical efficiency of 58.2% based on lower heating value (LHV).  相似文献   

11.
《Biomass & bioenergy》2005,28(2):171-182
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.  相似文献   

12.
Since fossil fuels have been broadly recognized as a non-renewable energy source that threatens the climate, sustainable and CO2 neutral energy sources - such as forest fuels - are being promoted in Europe, instead. With the expeditiously growing forest fuel demand, the strategic problem of how to design a cost-efficient distribution network has evolved. This paper presents an MILP model, comprising decisions on modes of transportation and spatial arrangement of terminals, in order to design a forest fuel supply network for Austria. The MILP model is used to evaluate the impacts of rising energy costs on procurement sources, transport mix and procurement costs on a national scale, based on the example of Austria. A 20% increase of energy costs results in a procurement cost increase of 7%, and another 20% increase of energy costs would have similar results. While domestic waterways become more important as a result of the first energy cost increase, rail only does so after the second. One way to decrease procurement costs would be to reduce the share of empty trips with truck and trailer. Reducing this share by 10% decreases the average procurement costs by up to 20%. Routing influences the modal split considerably, and the truck transport share increases from 86% to 97%, accordingly. Increasing forest fuel imports by large CHPs lowers domestic competition and also enables smaller plants to cut their procurement costs. Rising forest fuel imports via ship will not significantly decrease domestic market shares, but they will reduce procurement costs considerably.  相似文献   

13.
This paper presents a techno-economic analysis of corn stover fired process heating (PH) and the combined heat and power (CHP) generation systems for a typical corn ethanol plant (ethanol production capacity of 170 dam3). Discounted cash flow method was used to estimate both the capital and operating costs of each system and compared with the existing natural gas fired heating system. Environmental impact assessment of using corn stover, coal and natural gas in the heat and/or power generation systems was also evaluated. Coal fired process heating (PH) system had the lowest annual operating cost due to the low fuel cost, but had the highest environmental and human toxicity impacts. The proposed combined heat and power (CHP) generation system required about 137 Gg of corn stover to generate 9.5 MW of electricity and 52.3 MW of process heat with an overall CHP efficiency of 83.3%. Stover fired CHP system would generate an annual savings of 3.6 M$ with an payback period of 6 y. Economics of the coal fired CHP system was very attractive compared to the stover fired CHP system due to lower fuel cost. But the greenhouse gas emissions per Mg of fuel for the coal fired CHP system was 32 times higher than that of stover fired CHP system. Corn stover fired heat and power generation system for a corn ethanol plant can improve the net energy balance and add environmental benefits to the corn to ethanol biorefinery.  相似文献   

14.
Corn (Zea mays L.) cobs are being evaluated as a potential bioenergy feedstock for combined heat and power generation (CHP) and conversion into a biofuel. The objective of this study was to determine corn cob availability in north central United States (Minnesota, North Dakota, and South Dakota) using existing corn grain ethanol plants as a proxy for possible future co-located cellulosic ethanol plants. Cob production estimates averaged 6.04 Tg and 8.87 Tg using a 40 km radius area and 80 km radius area, respectively, from existing corn grain ethanol plants. The use of CHP from cobs reduces overall GHG emissions by 60%–65% from existing dry mill ethanol plants. An integrated biorefinery further reduces corn grain ethanol GHG emissions with estimated ranges from 13.9 g CO2 equiv MJ−1 to 17.4 g CO2 equiv MJ−1. Significant radius area overlap (53% overlap for 40 km radius and 86% overlap for 80 km radius) exists for cob availability between current corn grain ethanol plants in this region suggesting possible cob supply constraints for a mature biofuel industry. A multi-feedstock approach will likely be required to meet multiple end user renewable energy requirements for the north central United States. Economic and feedstock logistics models need to account for possible supply constraints under a mature biofuel industry.  相似文献   

15.
Bagasse is selected as the biomass source that is studied because of its annual significant rate production in Iran and potential for energy generation. Bagasse has been as an energy source for the production of energy required to run the sugar factory. The energy needed by factories was supplied by burning bagasse directly inside furnaces, which had an exceptionally low output. To this end, today, a secondary use for this waste product is in combined heat and power plants where its use as a fuel source provides both heat and power. In addition, low efficiency of traditional methods was caused to increase the use of modern methods such as anaerobic digestion, gasification and pyrolysis for the production of bio‐fuels. In this paper, the energy conversion technologies are compared and ranked for the first time in Iran. Therefore, the most fundamental innovation of this research is the choice of the best energy conversion technology for the fuel production with a higher efficiency. To assess the feasibility application and economic benefit of biogas CHP plant, a design for a typical biogas unit is programmed. The results show the acceptable payback period; therefore, economically and technically, biogas CHP plant appears to be an attractive proposition in Iran. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

16.
Increased inclusion of biomass in energy strategies all over the world means that greater mobilisation of biomass resources will be required to meet demand. Strategies of many EU countries assume the future use of non-EU sourced biomass. An increasing number of studies call for the UK to consider alternative options, principally to better utilise indigenous resources. This research identifies the indigenous biomass resources that demonstrate the greatest promise for the UK bioenergy sector and evaluates the extent that different supply chain drivers influence resource availability.The analysis finds that the UK's resources with greatest primary bioenergy potential are household wastes (>115 TWh by 2050), energy crops (>100 TWh by 2050) and agricultural residues (>80 TWh by 2050). The availability of biomass waste resources was found to demonstrate great promise for the bioenergy sector, although are highly susceptible to influences, most notably by the focus of adopted waste management strategies. Biomass residue resources were found to be the resource category least susceptible to influence, with relatively high near-term availability that is forecast to increase – therefore representing a potentially robust resource for the bioenergy sector. The near-term availability of UK energy crops was found to be much less significant compared to other resource categories. Energy crops represent long-term potential for the bioenergy sector, although achieving higher limits of availability will be dependent on the successful management of key influencing drivers. The research highlights that the availability of indigenous resources is largely influenced by a few key drivers, this contradicting areas of consensus of current UK bioenergy policy.  相似文献   

17.
Solid oxide fuel cells (SOFCs) have received attention in the transport sector for use as auxiliary power units or range extenders, due to the high electrical efficiency and fuelling options using existing fuel infra structure. The present work proposes an SOFC/battery powered vehicle using compressed natural gas (CNG), liquefied natural gas (LNG) or liquefied petroleum gas (LPG) as fuels. A model was developed integrating an SOFC into a modified Nissan Leaf Acenta electrical vehicle and considering standardized driving cycles. A 30 L fuel tank and 12 kW SOFC module was simulated, including a partial oxidation fuel reformer. The results show a significant increase of the driving range when combining the battery vehicle with an SOFC. Ranges of 264 km, 705 km and 823 km using respectively CNG, LNG and LPG compared to 170 km performed by the original vehicle were calculated. Furthermore, a thorough sensitivity analysis was carried out.  相似文献   

18.
Here we examine the cost, primary energy use, and net carbon emissions associated with removal and use of forest residues for energy, considering different recovery systems, terrain, forwarding distance and forest productivity. We show the potential recovery of forest fuel for Sweden, its costs and net carbon emissions from primary energy use and avoided fossil carbon emissions. The potential annual net recovery of forest fuel is about 66 TWh, which would cost one billion €2005 to recover and would reduce fossil emissions by 6.9 Mt carbon if coal were replaced. Of the forest fuel, 56% is situated in normal terrain with productivity of >30 t dry-matter ha?1 and of this, 65% has a forwarding distance of <400 m. In normal terrain with >30 t dry-matter ha?1 the cost increase for the recovery of forest fuel, excluding stumps, is around 4–6% and 8–11% for medium and longer forwarding distances, respectively. The stump and small roundwood systems are less cost-effective at lower forest fuel intensity per area. For systems where loose material is forwarded, less dry-matter per hectare increases costs by 6–7%, while a difficult terrain increases costs by 3–4%. Still, these systems are quite cost-effective. The cost of spreading ash is around 40 €2005 ha?1, while primary energy use for spreading ash in areas where logging residues, stumps, and small roundwood are recovered is about 0.025% of the recovered bioenergy.  相似文献   

19.
This paper explores the inter-linkages of gender, energy use, health and hardships in the Himalayan State of Himachal Pradesh in India. It brings out a gender-differentiated and age-differentiated picture of hardships and health impact on the use of traditional biofuels. The study is based on survey with questionnaires covering 4296 individuals, 729 households, 84 villages and 9 districts where biomass fuels meet 70% of household fuel needs. On an average, women walk 30 km each month taking 2.7 h per trip for fuel wood collection over hilly terrain, often at high altitudes and undergo stress like stiff-neck, backache, headache and loss of work days. Girls below 5 and females in 30–60 age-groups have higher proportion of respiratory symptoms than males of similar age-groups. While many studies are done on the health impact of cooking fuels, very little quantitative work is done on the other aspects of the fuel chain viz. collection, transportation and processing of fuels. Such studies would guide energy policy and health policy to improve the lives of women.  相似文献   

20.
Wildfire burnt forest biomass can be salvaged as feedstock for bioenergy power generating stations. Despite availability of such forest biomass in northwestern Ontario, its procurement has generally been considered uneconomic and no studies have looked into the cost of harvesting, processing, and transporting the burnt material for bioenergy production. In order to meet the demand of biomass for proposed and existing power generating stations using renewable fuels, a standard costing model is used to determine the feasibility of procuring biomass from burnt areas using a full-tree to roadside, roadside grinder to mill system. The case-study was conducted at the Hogarth Plantations near Thunder Bay, Ontario, Canada. The total cost incurred for processing and delivery of biomass from wildfire burnt area with a hauling distance of 7 km and total trip cycle time of 2.55 h was found to be $29.65 gt?1, with net energy content of 11.4 GJ gt?1. The total procurement cost depends on the hauling distance and a linear relationship between the two was established. The energy analysis found a net energy output to input ratio of 35:1 for the operation.  相似文献   

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