Biomass Gasification Combined Cycle Research Articles

Continuous decentralized hydrogen production through alkaline water electrolysis powered by an oxygen-enriched air integrated biomass gasification combined cycle

This research work presents an innovative approach for continuous decentralized production of renewable hydrogen from woody biomass. Alkaline water electrolysis (AWE) is used to produce high-purity hydrogen, while the oxygen by-product is mixed with ambient air and used to fire a biomass-fueled downdraft gasifier in order to produce an upgraded producer gas with a lower heating value (LHV) between 7–8 MJ/Nm3. This fuel gas is then subjected to a conditioning stage and eventually fed to a combined cycle consisting of a recuperative gas turbine as topping unit and a regenerative subcritical organic Rankine cycle as bottoming unit, which together allow for a combined electric power generation efficiency close to 40%. Most of the net AC power from the integrated gasification combined cycle (IGCC) is rectified to DC power and ultimately used to power an alkaline electrolyzer, with a minor share allocated to all the required utilities and ancillary equipment, including hydrogen compression to 200 bar. The results from simulation of the hybrid IGCC-AWE plant under steady-state operating conditions in Aspen Plus V.11 indicate an optimal efficiency of 17.6% based on the LHV of hydrogen. Thus, if sized for a biomass consumption of 1 t/h, the proposed plant is capable of providing around 26 kg/h of compressed hydrogen at 200 bar.

Study on the effect of gasification agents on the integrated system of biomass gasification combined cycle and oxy-fuel combustion

Abstract An integrated system of biomass gasification combined cycle with oxy-fuel combustion was proposed. Considering the neutral character of biomass, the “negative emissions” were achieved. Different gasifying agents, including steam, CO2, steam + O2, CO2 + O2, steam + CO2, and steam + CO2 + O2 were examined. The steam and CO2 in gasifying agents were directly separated from flue gas in power generation unit. The effects of equivalence ratios and gasifying agent to biomass ratios on syngas production were studied. The results revealed that steam contributed to the yield of H2, while it inhibited the generation of CO. CO2 in the gasifying agent promoted the yield of CO. O2 had little impact on H2 production, but it significantly reduced the generation of CO and CH4. The introduction of O2 in gasifying agent reduced the syngas LHV while it generally raised the gasification efficiency. Furthermore, when O2 was used to realize the autothermal gasification process, the net power generation efficiencies under steam + O2 gasification, CO2 + O2 gasification and steam + CO2 + O2 gasification were 26.3%, 28.3% and 27.6%, respectively. These efficiencies were competitive considering the biomass disposal and carbon capture.

Development of a novel renewable energy system integrated with biomass gasification combined cycle for cleaner production purposes

Abstract A new multigeneration system is proposed to utilize solar energy and biomass sources in a combined manner for cleaner production. The useful commodities of electricity, freshwater, cooling, ammonia and hydrogen are produced. A biomass based integrated gasification combined cycle system is used that is integrated with a solar tower thermal power plant. Also, the reverse osmosis entailing saline water treatment system is incorporated. Furthermore, a thermoelectric generator is deployed to generate power through the excess heat contained in the syngas produced. The developed system is analysed and assessed through thermodynamic analyses. The proposed system provides an increase in the overall efficiencies of renewable energy systems through new waste heat recovery approaches. The energy efficiency of the overall system is evaluated as 20.1% and the exergy efficiency of the overall system is determined to be 21.1%. However, the energy efficiency of the solar tower power plant is determined to be 14.7% and the exergy efficiency is found to be 15.6%. The hydrogen and ammonia production rates are 20 g/s and 79 g/s, respectively. A parametric analysis is carried out to assess the effects of varying operating conditions and system parameters on the system efficiencies.

Energy and exergy analyses of an integrated biomass gasification combined cycle employing solid oxide fuel cell and organic Rankine cycle

In this study, an advanced combined cycle-based power generation system, integrating biomass gasification with a solid oxide fuel cell (SOFC) module and an organic vapor turbine, has been modeled and analyzed. The thermodynamic model has been developed by integrating the component models through customized codes written using engineering equation solver software. Both energetic and exergetic analyses of the proposed system have been conducted under varying design and operating parameters to assess their effects on the performance of the proposed system. The study reveals that the integrated system yields a maximum overall energetic efficiency of 41.13%, occurring at a pressure ratio of 2.5 for the compressor. The gasifier is the component responsible for maximum exergy destruction (accounting for 32.36% of fuel exergy input), followed by the heat recovery vapor generator and the SOFC.

An update technology for integrated biomass gasification combined cycle power plant

A discussion is presented on the technical analysis of a 6.4 MWe integrated biomass gasification combined cycle (IBGCC) plant. It features three numbers of downdraft biomass gasifier systems with suitable gas clean-up trains, three numbers of internal combustion (IC) producer gas engines for producing 5.85 MW electrical power in open cycle and 550 kW power in a bottoming cycle using waste heat. Comparing with IC gas engine single cycle systems, this technology route increases overall system efficiency of the power plant, which in turn improves plant economics. Estimated generation cost of electricity indicates that mega-watt scale IBGCC power plants can contribute to good economies of scale in India. This paper also highlight’s the possibility of activated carbon generation from the char, a byproduct of gasification process, and use of engine’s jacket water heat to generate chilled water through VAM for gas conditioning.

Influence of dryer type on the performance of a biomass gasification combined cycle co-located with an integrated pulp and paper mill

Integration of biomass gasification with a pulp and paper mill is a possible route to create more value-added products. This route facilitates, for example, more advanced electricity generation and production of biomass based transportation fuels or chemical feedstock. Each unit operation in such a process affects overall efficiency as well as possibilities for process integration. In this paper, the impact of different dryer types in a biomass gasification combined cycle (BIGCC) has been evaluated in terms of efficiency and economic performance. The BIGCC was sized so that the excess heat would replace the current steam production from bark and oil. The results show that the dryer type can have a significant impact on economic performance and efficiencies. A BIGCC with an integrated belt dryer, utilizing excess heat to heat the drying air from the mill, can result in electrical efficiencies of up to around 40%, while e.g. a steam dryer can reach 36–37%. Choice of oxidant, air or oxygen, in the gasifier affects both capital and operational cost. Air was proven to be the most cost efficient solution for the cases evaluated in this study. The investment of around 100 to 140 million Euros for a BIGCC facility is profitable for most evaluated cases for an annuity factor of 0.1, while the net annual profit is negative for most cases when the annuity factor was increased to 0.2, even when including financial support for renewable electricity.

Techno-Economic Analysis of the Use of Fired Cogeneration Systems Based on Sugar Cane Bagasse in South Eastern and Mid-Western Regions of Mexico

In this paper two cogeneration systems (Biomass steam turbines and biomass gasification combined cycle) were evaluated and compared based on their potential to meet heat and power requirements of sugar/alcohol plants in two regions of Mexico (south eastern and mid western), which are both characterized by higher production rates of sugar cane. In addition, the potential of those systems to produce an electricity surplus was evaluated as a means to generate additional income in terms of co-product credit. The latter was evaluated in order to reduce the total production cost of fuel ethanol and identify a potential electricity surplus for use by local inhabitants. The analysis was performed comparing different scenarios based on the use of the current planted area in these regions to produce ethanol. Biomass integrated gasification combined cycle system was proven as the most advantageous system to meet heating requirements, generating an important amount of electricity with contribution of about 18 % in reduction of the total production cost of ethanol. Moreover, results indicate the potential to strengthen relations between the two regions with higher opportunities to increase incomes, as well as the improvement of added value cane bagasse with off-season electricity generation.

Fossil fuel savings, carbon emission reduction and economic attractiveness of medium-scale integrated biomass gasification combined cycle cogeneration plants

The paper theoretically investigates the system made up of fluidized bed gasifier, SGT-100 gas turbine and bottoming steam cycle. Different configurations of the combined cycle plant are examined. A comparison is made between systems with producer gas (PG) and natural gas (NG) fired turbine. Supplementary firing of the PG in a heat recovery steam generator is also taken into account. The performance of the gas turbine is investigated using in-house built Engineering Equation Solver model. Steam cycle is modeled using GateCycleTM simulation software. The results are compared in terms of electric energy generation efficiency, CO2 emission and fossil fuel energy savings. Finally there is performed an economic analysis of a sample project. The results show relatively good performance in the both alternative configurations at different rates of supplementary firing. Furthermore, positive values of economic indices were obtained.

Integrated biomass gasification combined cycle distributed generation plant with reciprocating gas engine and ORC

Abstract The paper theoretically investigates the performance of a distributed generation plant made up of gasifier, Internal Combustion Engine (ICE) and Organic Rankine Cycle (ORC) machine as a bottoming unit. The system can be used for maximization of electricity production from biomass in the case where there is no heat demand for cogeneration plant. To analyze the performance of the gasifier a model based on the thermodynamic equilibrium approach is used. Performance of the gas engine is estimated on the basis of the analysis of its theoretical thermodynamic cycle. Three different setups of the plant are being examined. In the first one the ORC module is driven only by the heat recovered from engine exhaust gas and cooling water. Waste heat from a gasifier is used for gasification air preheating. In the second configuration a thermal oil circuit is applied. The oil transfers heat from engine and raw gas cooler into the ORC. In the third configuration it is proposed to apply a double cascade arrangement of the ORC unit with a two-stage low temperature evaporation of working fluid. This novel approach allows utilization of the total waste heat from the low temperature engine cooling circuit. Two gas engines of different characteristics are taken into account. The results obtained were compared in terms of electric energy generation efficiency of the system. The lowest obtained value of the efficiency was 23.6% while the highest one was 28.3%. These are very favorable values in comparison with other existing small and medium scale biomass-fuelled power generation plants.

Performance analysis of integrated biomass gasification fuel cell (BGFC) and biomass gasification combined cycle (BGCC) systems

Biomass gasification processes are more commonly integrated to gas turbine based combined heat and power (CHP) generation systems. However, efficiency can be greatly enhanced by the use of more advanced power generation technology such as solid oxide fuel cells (SOFC). The key objective of this work is to develop systematic site-wide process integration strategies, based on detailed process simulation in Aspen Plus, in view to improve heat recovery including waste heat, energy efficiency and cleaner operation, of biomass gasification fuel cell (BGFC) systems. The BGFC system considers integration of the exhaust gas as a source of steam and unreacted fuel from the SOFC to the steam gasifier, utilising biomass volatilised gases and tars, which is separately carried out from the combustion of the remaining char of the biomass in the presence of depleted air from the SOFC. The high grade process heat is utilised into direct heating of the process streams, e.g. heating of the syngas feed to the SOFC after cooling, condensation and ultra-cleaning with the Rectisol ® process, using the hot product gas from the steam gasifier and heating of air to the SOFC using exhaust gas from the char combustor. The medium to low grade process heat is extracted into excess steam and hot water generation from the BGFC site. This study presents a comprehensive comparison of energetic and emission performances between BGFC and biomass gasification combined cycle (BGCC) systems, based on a 4th generation biomass waste resource, straws. The former integrated system provides as much as twice the power, than the latter. Furthermore, the performance of the integrated BGFC system is thoroughly analysed for a range of power generations, ∼100–997 kW. Increasing power generation from a BGFC system decreases its power generation efficiency (69–63%), while increasing CHP generation efficiency (80–85%).

Biofuel Based Cogenerative Energy Conversion Systems

The goal of this study is to investigate how co-operation between industry and district heating companies can improve profitability of biofueled cogenerative investments in small to medium-sized applications. Currently advanced biomass gasification and gas turbine combined cycle has been found to be a promising cogenerative conversion technology for the recovery of heat present in biomass fuel. Increased biofuel based cogenerative power production in the future is clearly dependent on the improvement of both performance and investment costs of new high performance technology, and on the nature of policy instruments designed to promote the technology. The use of biofuels for cogeneration on a large scale is focused mainly on forest industry sites, where considerable quantities of biomass are available. While cogeneration provides several environmental benefits by making use of waste heat and waste products, air pollution is a concern any time fossil fuels or biomass are burned.

05/02590 Life cycle assessment (LCA) of an integrated biomass gasification combined cycle (IBGCC) with CO 2 removal

05/02590 Life cycle assessment (LCA) of an integrated biomass gasification combined cycle (IBGCC) with CO 2 removal

New Opportunities Resulting from Cogeneration Systems Based on Biomass Gasification

Cogeneration (COGEN) is defined as the combined production of two forms of energy (electric or mechanical power plus useful thermal energy) in one technological process. The COGEN is considered worldwide as the major option to achieve considerable energy saving with respect to traditional systems. The heat produced from the electricity generating process is captured and utilized to produce domestic purposes and can be used in steam turbines to generate additional electricity. Facilities with COGEN systems use them to produce their own high and low level steam. Currently, advanced biomass gasification and gas turbine combined cycle has been found to be a promising cogenerative conversion technology for the recovery of heat present in biomass fuel. Increased biofuel based cogenerative power production in the future is clearly dependent on the improvement of both performance and investment costs of new high performance technology, and on the nature of policy instruments designed to promote the technology.

Life cycle assessment (LCA) of an integrated biomass gasification combined cycle (IBGCC) with CO2 removal

Based on the results of previous studies, the efficiency of a Brayton/Hirn combined cycle fuelled with a clean syngas produced by means of biomass gasification and equipped with CO2 removal by chemical absorption reached 33.94%, considering also the separate CO2 compression process. The specific CO2 emission of the power plant was 178 kg/MW h. In comparison with values previously found for an integrated coal gasification combined cycle (ICGCC) with upstream CO2 chemical absorption (38–39% efficiency, 130 kg/MW h specific CO2 emissions), this configuration seems to be attractive because of the possibility of operating with a simplified scheme and because of the possibility of using biomass in a more efficient way with respect to conventional systems. In this paper, a life cycle assessment (LCA) was conducted with presenting the results on the basis of the Eco-Indicator 95 impact assessment methodology. Further, a comparison with the results previously obtained for the LCA of the ICGCC was performed in order to highlight the environmental impact of biomass production with fossil fuels utilisation. The LCA shows the important environmental advantages of biomass utilisation in terms of reduction of both greenhouse gas emissions and natural resource depletion, although an improved impact assessment methodology may better highlight the advantages due to the biomass utilisation.

Biomass gasification combined cycle — a shared opportunity for the nation and industry

Biomass gasification combined cycle — a shared opportunity for the nation and industry

98/03915 Technoeconomic analysis and life cycle assessment of an integrated biomass gasification combined cycle system

98/03915 Technoeconomic analysis and life cycle assessment of an integrated biomass gasification combined cycle system