Biomass Power Generation System Research Articles

Forest resource distribution and transport cost optimization-based economic evaluation of gasification and steam-turbine biomass power generation systems

The economics of decentralized gasification and centralized steam turbine systems with optimized harvesting, chipping, and transportation costs of unutilized forest biomass were analyzed within the context of the spatial distribution of forest biomass resources using a geographic information system in the Fuji area of Shizuoka Prefecture, Japan. The optimized harvesting, chipping, and transportation costs were 62.50 USD/dry-t for the decentralized system and 65.86 USD/dry-t for the centralized system, confirming that the decentralized system was less expensive than the centralized system. However, electricity production costs for centralized systems, ranging from 0.137 USD/kWh (capacity: 5,000 kW), were found to be more economical than that for decentralized systems, at 0.151–0.165 USD/kWh (capacity: 482 kW), resulting in the higher costs of decentralized systems because of expensive initial investment than that of the centralized system. The rate of heat sold, which lowers the electricity production costs of gasification below those of centralized systems, was 20–40 % for all such plants. To lower the electricity production cost of gasification plants below that of steam-turbine systems, a heat sales rate of approximately 10% and a minimum staff of 0.2 persons for remote operation of the gasification system. Higher heat sales rates further decrease the cost of gasification, making it cheaper than steam-turbine systems even at lower operating rates. To achieve this cost advantage at current low utilization rates, a heat sales rate of 50% and a utilization rate of 90%, based on a unit price of 0.05 USD/kWh, are required.

Performance analysis of a compressed air energy storage incorporated with a biomass power generation system

Compressed air energy storage technology is recognized as a promising method to consume renewable energy on a large scale and establish the safe and stable operation of the power grid. To improve the energy efficiency and economic performance of the compressed air energy storage system, this study proposes a design for integrating a compressed air energy storage system with a biomass power generation system. In the energy storage process, the feedwater from the biomass power generation system is used to cool the compressed air in the compressed air energy storage system. In the energy release process, the flue gas from the biomass power generation system is used to heat the compressed air. Besides, the compressed air from the compressed air energy storage system first works in the expander and then goes to the biomass power generation system for combustion. Based on the system simulation, the proposed system is assessed from the energy, exergy, economy, and environment perspectives. The results show that the round-trip efficiency and the energy storage density of the compressed air energy storage subsystem are 84.90 % and 15.91 MJ/m3, respectively. The exergy efficiency of the compressed air energy storage subsystem is 80.46 %, with the highest exergy loss in the throttle valves. The total investment of the compressed air energy storage subsystem is 256.45 k$, and the dynamic payback period and the net present value are 4.20 years and 340.48 k$. Besides, the proposed system’s CO2 emission is 258 kg/GWh. This study provides a new option for enhancing the performance of compressed air energy storage through the system integration.

High-efficient and carbon-free biomass power generation hybrid system consisting of chemical looping air separation and semi-closed supercritical CO2 cycle with a bottoming organic Rankine cycle

Herein, a novel biomass power generation system, comprising of CO2-assisted gasification unit, chemical looping air separation (CLAS) unit, semi-closed supercritical CO2 (sCO2) cycle with the bottoming ORC unit, was proposed to overcome the problems of low-efficiency and high-pollution rendered by traditional biomass utilization method. And the heat integration between those subunits was well designed based on the principle of energy cascade utilization. The sensitive analysis was carried out to clarify the reasons behind thermodynamic performance variation, and the optimized net power efficiency reached 38.76% when the CO2/C ratio was 0.25, gasification temperature was 830 °C, sCO2 turbine inlet temperature and pressure were 1200 °C and 300 bar respectively, which was superior to 28.01% of biomass integrated gasification combined cycle system. In addition, the exergy analysis found that modification efforts should be exerted on CLAS and sCO2 compression pump, whose exergy destruction were 7.58 MW and 5.15 MW, respectively. Besides, its environmental and economic merits were obvious with the CO2 specific emission at 0.31 kg/MWh, and the levelized cost of electricity at 57.38 $/MWh. Furthermore, three typical biomasses were examined for the proposed system, the results showed that the dryer and carbon-richer biomass could benefit system thermodynamic and economic performance.

Test and performance optimization of nozzle inclination angle and swirl combustor in a low-tar biomass gasifier: a biomass power generation system perspective

A nozzle inclination angle and swirl combustor inside the low-tar biomass (LTB) gasifier reactor were tested and optimized to evaluate these effects on tar reduction to design tar-free producer gas. The tar reduction process is mainly based on the concept of a swirling flow created by the nozzle inclination angle, with the inclination angle of 55° to the radial line, allowing good mixing between pyrolysis gases and gasifying agents. A separate swirl combustor has created large internal annular and reverses flow zones with the help of swirl flow, resulting in homogenized temperature inside the combustor and providing longer residence time; both have a positive effect on the combustion of mixed gasifying air-pyrolysis gases by the thermal cracking in the partial oxidation zone. Recircling ratio (RR) and combustion degree of volatiles are the two optimization parameters for evaluating the performance of NIA and swirl combustor. The result observed that outstanding tar reduction occurred in this novel system. About 86.5 and 12.8% of tar compounds are broken down in the partial oxidation zone and pyrolysis zone using the novel swirl combustor and NIA, respectively; gas outlet has observed producer gas having tar concentration of less than 1%. The optimization results reveal that a lower recycling ratio (recycle gas/gasifying air) and a higher combustion degree of volatiles perform better in biomass gasification. Finally, this system generated producer gas with the tar concentration at an extremely low level of 7.4 mg/Nm3 for a biomass moisture content of 9% and appeared the lower heating value of 4.6–5.1 MJ/Nm3. This lower tar concentration might be directly coupled with an internal combustion engine or a gas turbine for power generation.

Updraft Gasifier-Stirling Engine Biomass Incineration System Power Generation

Biomass, the world's largest renewable energy source, will continue to grow in the following energy markets. As a result, small biomass conversion systems are more competitive than large stand-alone converters because most of the biomass sources have low energy density and are widely distributed in space. The current study offers a small solid biomass power generation system to examine the possibility of direct connection of updates fixed bed gasifiers and a Stirling engine. The fixed bed updraft gasifier uses a combustion burner built into the gasifier to completely burn the synthetic gas produced by the gasifier. The exhaust gases generated by the synthesis gas combustion in the combustion tube are directed to the Stirling engine heater head. The engine then converts the heat contained in the exhaust gases. Output depends on the heat input. And the heat input is proportional to the flue gas flow rate and temperature Preliminary studies on the proposed straight couplings of the energy derived from the gasifier to mechanical energy of 300 mW and electrical energy of 50 mW. The outcomes of the Stirling engine with Updraft gasifier test shows that Pradauk biomass is more effective than charcoal biomass. Current research shows that no supplemental fuel is needed to keep the current system running smoothly. The technology and units presented can be considered as a viable solid biomass power generation system and enlarge to produce more electricity in rural areas of Thailand in the next step.
 HIGHLIGHTS
 
 The outcomes of the Stirling engine with Updraft gasifier test shows that Pradauk biomass is more effective than charcoal biomass
 The technology and units presented can be considered as a viable solid biomass power generation system and enlarge to produce more electricity in rural areas of Thailand in the next step
 Current studies show that the proposed system is technically feasible because it can generate electricity without interference so as to maintain an almost stable process
 
 GRAPHICAL ABSTRACT

【基調講演】ガス化分野 バイオマス発電システムの高度化:燃焼の高付加価値化とエネルギー貯蔵との統合

【基調講演】ガス化分野 バイオマス発電システムの高度化:燃焼の高付加価値化とエネルギー貯蔵との統合

Valorization of Biomass Power Generation System: Noble Use of Combustion and Integration with Energy Storage

For the development of sustainable energy and a great reduction of CO2 emission into the atmosphere, renewable energy has been rapidly installed and used in the last two decades. Many biomass power plants have been built and operated because the combustion of biomass is considered to be renewable and carbon neutral. In this review, the following topics are summarized: (1) economic values of bioproducts, (2) many restrictions of biomass power generation systems such as (i) very low energy efficiency from solar power to electricity, (ii) limiting amount of resource, and (iii) requirement of fuel cost for operation, and (3) characteristics of combustion technologies including drawbacks and the following strong points: (i) high power, (ii) high-temperature heat generation, and (iii) utilization for hygiene or sanitation purposes. The reduction of simple combustion and the noble use of combustion technology by effectively utilizing these strongpoints are required to greatly reduce CO2 emission even if renewable biomass is used. Next-generation biomass power generation systems integrated with variable renewable energy and energy storage system for non-steady-state operation are proposed as a promising method to balance the intermittent electricity supply by variable renewable energy and electricity demands.

Development of High Efficiency/Output External Combustion Engine and Advocation of Application to Biomass Power Generation System

Development of High Efficiency/Output External Combustion Engine and Advocation of Application to Biomass Power Generation System

アカマツ林施業を考慮した木質系バイオマス発電システムの環境影響評価

アカマツ林施業を考慮した木質系バイオマス発電システムの環境影響評価

A biomass power generation system combined with sewage sludge incineration

A biomass power generation system combined with sewage sludge incineration

Biomass energy cost and feasibility of gasifier based biomass power generation system

Abstract: The present research work has been carried out on biomass based on 10 kW capacity gasifier power generation system installed at College of Agricultural Engineering and Technology, Dr. Panjabrao Deshmukh Agricultural University (Dr. PDKV), Akola Maharashtra, India. The main objectives were to evaluate various costs and benefits involved in the power generation system. The costs of energy per unit were calculated for the first year of operation. The economics of gasifier based power generation system and thereby the feasibility of the system was examined by estimating per unit cost, Net Present Value (NPV), Benefit Cost Ratio (BCR), Internal Rate of Return (IRR) and payback period. The discount cash flow method was used to find out the IRR. In the present analysis, three costs viz., installed capital cost, operation and maintenance cost, and levelised replacement cost were examined for the evaluation of the power generation per unit. Discount rate on investment in case of subsidy (Case I) and in case without subsidy (Case II) for installation cost of system was considered as 12.75%. The BCR comes in Case I for operating duration of 22 h, 20 h, and 16 h are 1.24, 1.18, and 1.13, respectively. Similarly for Case II BCR comes 1.44, 1.38, and 2.39. The IRR comes in Case I for operating duration of 22 h, 20 h, and 16 h are 26%, 22%, and 19%, respectively. Similarly for Case II, IRR comes 52%, 44%, and 39% for operating duration of 22 h, 20 h, and 16 h, respectively. The payback period in the present analysis was worked out. The payback period for biomass based gasifier power generation system was observed to be for Case I from three to four years and for Case II it was one to two years. Keywords: cost of biomass energy, biomass power generation system discounted cash flow, benefit cost ratio, net present value,payback period, internal rate of return DOI: 10.3965/j.ijabe.20130604.007 Citation: Khambalkar V P, Kankal U S, Karale D S, Gangde C N. Biomass energy cost and feasibility of gasifier based biomass power generation system. Int J Agric & Biol Eng, 2013; 6(4): 55－63.

Quantitative Estimation of Biomass Energy and Evaluation of Biomass Utilization - A Case Study of Jilin Province, China

Jilin Province, as a large agricultural province, has abundant reserve of biomass resources. At the same time Jilin Province is currently suffering from energy shortage. Besides, consumption of conventional fossil fuels has resulted in the exacerbation of global warming and air pollution. Biomass energy as a renewable and substitutive energy, can mitigate the energy crisis and global warming, and improve environmental quality once it is fully utilized. This paper estimated the supply potential of biomass energy and integrated LCA and environmental cost analysis to make evaluation on biomass utilization taking biomass power generation system as example. Acquirable and utilizable amount of biomass energy in Jilin Province is equivalent to 21.26 tce, which can be accounted for 25.6% of total energy consumption in Jilin Province in 2011. Among all biomass energy, 59.1% comes from straw and agricultural residues, followed by 33.8% from livestock manure. According to the LCA results, total environmental impact of biomass power generation system is 0.721, much smaller than 25.321 of thermal power generation system. General cost of biomass power generation is higher, however its environmental cost is much lower than thermal power generation system (396 yuan/104kWh < 1819 yuan/104kWh). The results showed that biomass utilization has better environmental advantages and has the potential for the mitigation of energy crisis in Jilin Province.

A GIS (geographical information system)-based spatial data mining approach for optimal location and capacity planning of distributed biomass power generation facilities: A case study of Tumkur district, India

This paper primarily intends to develop a GIS (geographical information system)-based data mining approach for optimally selecting the locations and determining installed capacities for setting up distributed biomass power generation systems in the context of decentralized energy planning for rural regions. The optimal locations within a cluster of villages are obtained by matching the installed capacity needed with the demand for power, minimizing the cost of transportation of biomass from dispersed sources to power generation system, and cost of distribution of electricity from the power generation system to demand centers or villages. The methodology was validated by using it for developing an optimal plan for implementing distributed biomass-based power systems for meeting the rural electricity needs of Tumkur district in India consisting of 2700 villages. The approach uses a k-medoid clustering algorithm to divide the total region into clusters of villages and locate biomass power generation systems at the medoids. The optimal value of k is determined iteratively by running the algorithm for the entire search space for different values of k along with demand–supply matching constraints. The optimal value of the k is chosen such that it minimizes the total cost of system installation, costs of transportation of biomass, and transmission and distribution. A smaller region, consisting of 293 villages was selected to study the sensitivity of the results to varying demand and supply parameters. The results of clustering are represented on a GIS map for the region.

The Energy Consumption and Environmental Impacts of Biomass Power Generation System in China

Combined with practical operation of a biomass direct-fired power pant in South China, the whole life cycle of the process, including biomass growing, transportation, pretreatment, combustion power generation and power plant manufacturing are analyzed by means of LCA. The energy consumption and the impact on environment in each stage are also collected and calculated. The results show that 2182.32 MJ fossil energy is consumed to generate 104 kWh power. The total loading of the impact on environment is 13.45 PET2000 and the mainly impact on environment is soot and ashes. Compared with coal-fired power, biomass direct-fired power plant can reduce 5282.87 kg CO2 emissions during the process of generating 104 kWh power, which plays a positive part in mitigating greenhouse gases.

Low-Cost Bioenergy Options for Rural India

By using a decentralized energy-planning (DEP) approach, this paper shows that biomass-based energy systems have the potential to meet all the rural energy needs from village to district level. DEP has been formulated and applied to a typical Indian district (Tumkur). The main purpose of this study is to examine the economic feasibility of bioenergy for use in rural areas. Model analysis shows that the cost of producing biomass is very low per capita at the household level. Energy plantations could be raised on available degraded areas or wastelands. The biomass feedstock that can be produced from plantations is shown to be adequate to meet all the electricity needs of the village by using biomass gasification technology. Electricity demands can be met by using biomass power generation systems on the basis of biomass feedstock from energy plantations on available wastelands.

Evaluation of solar aided biomass power generation systems with parabolic trough field

Solar and biomass are both renewable energy resources. Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources. However the costs of power from a biomass power generation plant depend greatly on the availability and quality of the biomass resource. The commercialization of solar alone thermal power generation is hindered by its high initial investment and low thermal efficiency. In this paper, a concept of integrating solar into a biomass power generation system is put forward. In the system the oil heated by a parabolic trough solar field is used to replace the extraction steam to preheat the feed water (entering a biomass boiler) and the previous extraction steam thus saved can continue to do work in the lower stages of turbine. The performance of the hybrid system with different replacements is analyzed and compared through two typical solar aided biomass generating units. The results show that the integration not only reduces the consumption of biomass fuel (at the same generation capacity) but is also proved to be an efficient way to convert solar thermal energy into power. The results also show that with the same solar aperture area, the higher the grade of the replaced extraction steam, the better the thermal performance and economy.

The Development of Small-Scale Biomass Power Generation System by Pyrolysis Gasification

The Development of Small-Scale Biomass Power Generation System by Pyrolysis Gasification

6-9.バイオマスエネルギー利用による温暖化軽減効果 : バイオマス発電システム導入による代替炭素量見積(Session 2.5.6 バイオマス・新エネルギー・リサイクル)

6-9.バイオマスエネルギー利用による温暖化軽減効果 : バイオマス発電システム導入による代替炭素量見積(Session 2.5.6 バイオマス・新エネルギー・リサイクル)

持続的な植林によるバイオマス発電のＣＯ２排出削減量の評価 ＬＣＡ的検討

CO2 emission from biomass power generation system with sustain-able afforestation was evaluated by LCA (Life Cycle Assessment) methodology. Cal-culation was conducted for typical case (15km×15km). CO2 emission from sustainable afforestation system was calculated to be 2.1×107 kg-CO2/y. That from construction of biomass power plants was calculated to be 5.0×105 kg-CO2/y. CO2 emission from power plant construction was negligibly small. Net CO2 reduction effect of replacing coal by biomass was calculated to be 2.4×108 kg-CO2/y. It was suggested that the biomass power generation system possibly educes large quantity of CO2 emission by the replacement. CO2 emission from afforestation was about 8% of the CO2 reduction effect. Finally, the energy payback time of the biomass power generation system with sustain-able afforestation was calculated to be about 0.2 year.