Search

Biomass energy can alleviate global warming and solve energy depletion, which is increasingly concerned by the world. Due to the different emission reduction benefits and growth potential of different regions and biomass power generation technologies, analyzing the suitability of these technologies combined with regional conditions can more accurately guide the long- and short-term development of biomass power industry. However, there is no comprehensive evaluation of the benefits and potential of several biomass power generation technologies in different regions. Therefore, this paper introduces development suitability indexes and constructs life-cycle environmental impact and time-value economic impact assessment models, and a growth potential dynamic assessment model based on Gaussian process and particle swarm optimization to illustrate the greenhouse gas emission reduction benefits and growth potential of biomass power generation technologies. The empirical research of China shows that biomass gasification and direct combustion power generation can bring the best environmental benefits, and biogas power generation can bring the best economic benefits. For regions with abundant biomass resources and bad air condition, it is more suitable to develop gasification and direct combustion power generation technology, while mixed-combustion and biogas power generation technology are more suitable in regions with high electricity consumption. [ABSTRACT FROM AUTHOR]

The composite fuel of coal gangue and biomass is expected to increase the utilization rate of solid waste and compensate for the disadvantages of separate fuels. However, the NO and SO2 emissions from this composite fuel during the combustion process are a concern, but there are few studies on it. In this paper, corn cobs and wheat straws, typical agricultural biomass discarded in North China, and coal gangue from the mine in Xilingol, China, were selected for co-combustion in a fluidized bed. The emission characteristics of NO and SO2 were studied by changing the ratio of biomass to coal gangue and the combustion temperature. Studies had shown that: to a certain extent, mixing biomass, and coal gangue can reduce the NO and SO2 emissions, and mixing 20% of biomasses had the best effect on NO and SO2 emissions reduction. The SO2 emission reduction effect of wheat straws was better than that of corn cobs, and the NO emission reduction effect of corn cobs was better than that of wheat straws. The NO emissions of wheat straws and corn cobs added to the coal gangue were 6.45% and 7.93% less than those of coal gangue alone. The SO2 emissions of wheat straws and corn cobs added to the coal gangue were 27.45% and 25.94% less than those of coal gangue alone. Both NO and SO2 emissions decreased with the growth of the biomass rate; NO and SO2 emissions increased with the growth of the combustion temperature. [ABSTRACT FROM AUTHOR]

The processing of rice (Oryza sativa L.) generates large quantities of lignocellulosic wastes termed rice husks (RH). Numerous researchers have proposed biomass gasification as the panacea to the waste disposal and management challenges posed by RH. However, a comprehensive analysis of RH gasification is required to examine the research landscape and future directions on the area. The research landscape and global developments on RH gasification from 1995 to 2019 are examined through bibliometric analysis of 228 publications extracted from the Web of Science. Bioresource Technology is considered the most influential journal on the topic, whereas China is the most productive nation due to government policies and research funding. The most productive organization is the Harbin Institute of Technology, which is due to the significant contributions of Zhao YiJun and co-workers. Keyword analysis revealed three crucial research themes: gasification, biomass, and rice husks. The literature revealed that the syngas yield, distribution, and performance of RH gasification are significantly influenced by temperature, equivalence ratio, selected reactor, and gasifying medium. The techno-economic analysis of RH gasification revealed that government interventions such as high sales rates and low investment costs could enhance the commercial viability of the technology. Furthermore, the integration of RH gasification with carbon capture utilization and storage could promote the decarbonization of power plants, negative emissions, and net-zero climate goals. Overall, the paper provides valuable information for future researchers to identify strategic collaborators, journal publications, and research frontiers yet unexplored. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biomass fermentation and gasification are two types of biomass utilization technologies for residential households. Government plays an essential role in the diffusion of improved technologies. Cost-effectiveness analysis can provide the cost and abatement potentials of each alternative under a single abatement strategy; however, it is difficult for policy-makers to make an integrated assessment when multiple objectives are involved. This paper evaluates the performance of three distributed alternatives and two centralized alternatives for residential biomass use in rural China, including centralized biogas and centralized gasifier systems. An integrated assessment approach is built, which combines cost-benefit analysis, an entropy-weighting method, and a preference-ranking organization method for enrichment evaluations using the PROMETHEE approach. A total of 686 sample households in three regions of China were surveyed in this study. The centralized gasifier system and distributed household biogas were the top two alternatives for further development to meet the government's 2020 development goal for biogas technology. The overall biomass utilization amount in the prioritized scenario is about three times that of the business-as-usual scenario by 2020. This study can provide significant insights for China's policy-makers to draft strategic policies and countermeasures that will promote the development of renewable energy in China. [ABSTRACT FROM AUTHOR]

China's growing capacity of bioethanol production renders the conversion of ethanol-to-jet fuel (ETJ) promising. However, ETJ studies are currently scarce in China. This study employed process simulation to model two novel ETJ processes that combined corn cob gasification, syngas-to-ethanol, and ethanol-to-jet fuel. This paper also discussed the other three ETJs, in which ethanol were obtained via direct-fermentation of corn, cassava, and corn cob, respectively. Life cycle assessment (LCA) was performed to evaluate energy consumption and greenhouse gas (GHG) emissions of ETJs in China. The results showed that the ETJ pathway, which included corn cob gasification plus fermentation, showed the least energy consumption and GHG emission, with 370.05 KJ/MJ jet fuel and 31.66 gCO 2 eq/MJ jet fuel, respectively. Sensitivity analysis was performed to identify parameters that had a significant impact on the results, and uncertainty analysis was implemented to check the reliability of the result. Further analysis revealed that cleaner electricity and heat production could effectively reduce the GHG emissions of the energy-intensive ETJs, with the highest reduction of 21.55%. Given that few life cycle assessments of ETJs in China have reported, this study can assist policy-makers to decide the path in which China's sustainable aviation fuel (SAF) should evolve. [Display omitted] • Life cycle analysis for 5 ethanol-to-jet fuels established toward China situation. • The process based on corn-cob-syngas fermentation showed the best carbon reduction. • Optimizing biomass and ethanol conversion could greatly reduce GHG emissions. • Electricity mixes highly impacted on the process based on corn-cob-syngas catalysis. • Life cycle results were mostly sensitive to the displacement allocation method. [ABSTRACT FROM AUTHOR]

The extracts and extractive residues were obtained by single-stage extraction with acetone, CS2 and acetone/carbon disulphide solvent (IACDSM) under mild conditions, and they were then characterised by infrared and segmented peak fitting analysis. The results showed that acetone and CS2 solvents could dissolve more aromatic structures containing fatty side chains, while the mixed solvents could extract more phenolic substances. The acetone extracts were mainly asymmetric -CH2 stretching vibrations, while the remaining two extracts were dominated by aliphatic -CH. A comparison of the IR results of the tar residue and the three solvent extracts showed that the main structure of the tar residue was not altered throughout the process, but the aromatic structure was altered more by the extraction. Compared to the original sample, the proportion of tetrasubstituted or trisubstituted benzene rings in the three solvent extracts increased, while the proportion of pentasubstituted benzene rings produced a significant decrease. Comparison of the IR structural parameters showed that the aromatic ring condensation was higher in the as-received CS2 extracts and acetone extracts, with the acetone extracts having longer straight aliphatic chains and fewer branched chains. The analysis of the composition of the extraction results provides a reference basis for the separation and purification technology of coal tar residue, enabling the further development of China's coal chemical industry. [ABSTRACT FROM AUTHOR]

Biomass, as a renewable and clean energy resource, plays a vital role in energy security and greenhouse gas reduction across the world. This paper reports on our newly established technology: a downdraft fixed-bed biomass gasification system using nut shells (mainly apricot kernel shells) for electricity generation, heating and partially activated carbon production at the same time. Particularly, the key features of the gasification reactor will be presented in detail. In the commercial plant (3 MW scale) located in Hebei province, China, the typical energy conversion from apricot kernel shell gasification is as follows: 47% syngas, 44% char (partially activated carbon), 5% hot water, and 4% energy loss. The main gasification temperature is 600–800 °C, while the activation zone is 850–900 °C. The commercial system has currently been in operation for 4 years. Considering the partially activated carbon as a stable carbon carrier, the whole system features negative CO2 emissions. [ABSTRACT FROM AUTHOR]

• A new approach for the prediction and optimization of syngas production is proposed. • A numerical model for the study of biomass gasification is established. • Agricultural wastes of northeast China are first reported for gasification study. • The effects of operating conditions and biomass composition on syngas are studied. • The techno-economic analysis of three different agricultural wastes is carried out. Prior information regarding the effects of the operating conditions and biomass composition on the syngas production is critical to predict and optimize the syngas production. Therefore, this paper proposes an effective method to predict and optimize the syngas production by combining a process model and data analysis techniques. Three agricultural waste types from Northeast China and 56 biomasses with different compositions were used as the gasification feedstock to investigate the effects of the operating conditions and biomass composition on the syngas production. A validated Aspen Plus process model was implemented to realize the biomass gasification process and techno-economic analysis. The sensitivity analysis results indicated that a lower temperature (approximately 600 ℃) and lower steam-to-biomass ratio (S/B) (approximately 0.1) were the optimal operating conditions to achieve a higher lower heating value (LHV) of syngas. The introduction of steam changed the relationship between the temperature and LHV of syngas from inverse to direct. Furthermore, the performance comparison of the three agricultural waste based gasification processes indicated that a higher temperature and higher S/B could weaken the effect of the C, H, and O contents on the syngas composition. More importantly, the partial correlation analysis of the 56 sets of simulation results highlighted that a higher content of C and H, C/O and C/H helped enhance the LHV of syngas. The C/O value and C content exhibited the most significant correlations with the LHV of syngas, with correlation coefficients of 0.945 and 0.840, respectively. Correspondingly, these parameters exhibited a reasonable linear response with the LHV of syngas, with R2 values of 0.864 and 0.533, respectively. Finally, the techno-economic analysis indicated that SS is the optimal feedstock for syngas production. [ABSTRACT FROM AUTHOR]

Summary: Tremendous amounts of organic residue from manufacturing herbal medicines and inorganic red mud waste from mining bauxite ores are landfilled each year in China. To study the potential for their beneficial co‐use, chemical looping gasification (CLG) was tested in which the organic residue was used as the fuel and the red mud was the oxygen carrier that is needed for CLG. Parametric testing was performed using a thermo‐gravimetric analyzer and a bench‐scale fluidized bed reactor to optimize CLG operations that could maximum syngas production, enrich H2 concentrations and obtain effective conversion of the residue. Physical and chemical characterization of the organic residue and red mud before and after CLG testing showed that some filamentous ash from the organic residue remained on the surface after testing, and potassium from the organic residue migrated onto the surface of the oxygen carrier. The characterization and testing results suggested that CLG may be an advantageous technology to effectively convert an organic waste into syngas and an inorganic waste into a usable product, thereby establishing an approach for beneficial waste resource utilization. [ABSTRACT FROM AUTHOR]

Considering the current national conditions of China, developing coal-to-liquid process is an attractive way to alleviate the domestic oil crisis. Coal-to-liquid process mainly includes six subsystems and the most essential unit of the system is the gasification unit. This paper aims to provide suggestions for the cleaner production and sustainable development of coal-to-liquid technology. Lurgi, Texaco, and Shell coal-to-liquid process are modelled and simulated. The techno-economic analysis is conducted to investigate their performance using simulation-based results. Results showed that the greenhouse gas emissions of Lurgi, Texaco, and Shell coal-to-liquid process are 5.26 t/t fuel, 4.86 t/t fuel, and 3.49 t/t fuel. Lurgi coal-to-liquid has better performance on reducing oxygen cost and total investment; Texaco coal-to-liquid is advantageous in saving steam cost and production cost; Shell coal-to-liquid shows better performance in terms of energy efficiency, reducing the consumption of coal and water, and greenhouse gas emission. Shell gasifier is recommended in water-deficient areas. Texaco gasifier is recommended when access to water and coal is sufficient. Lurgi gasifier is recommended in pilot-scale projects. In the view of sustainable development, Shell gasifier is prior to Texaco gasifier and Lurgi gasifier because of the low greenhouse gas emission and well resistance to high coal price and high carbon taxes. Gasification unit occupies the largest proportion of total capital investment of coal-to-liquid processes and significantly affects the syngas composition. Coal gasification technology is potentially limiting the overall acceptance and practice of coal-to-liquid process in the future. Image 1 • Techno-economic analysis of coal-to-liquid processes are conducted. • Lurgi coal-to-liquid has a better performance on oxygen cost and total investment. • Texaco coal-to-liquid is shown to have a better performance on steam cost and production cost. • Shell coal-to-liquid has a better performance on energy efficiency, coal and water consumption. • Suggestions for cleaner production and future development of coal-to-liquid are provided. [ABSTRACT FROM AUTHOR]

Dependence on natural gas and oil as the main energy carriers has led to serious economic crisis and climate changes, especially in developing countries like China. Among the different renewable biomass materials currently available for power generation, agricultural residue is one of the feedstocks receiving more attention from researchers in the field of energy and agricultural science, probably due to its availability, low price, and socioeconomic advantages. In this work, a detailed study of various scenarios for electricity production such as combustion, pyrolysis, and gasification was carried out. After a detailed comparison, it was found that the gasification process is a better energy system for electricity production because of its total cost and environmental problems are lower than those of other methods. [ABSTRACT FROM AUTHOR]

Biomass gasification to produce burnable gas now attracts an increasing interest for production flexibility in the renewable energy system. However, the biomass gasification technology using dual fluidized bed which is most suitable for burnable gas production still encounters problems of low production efficiency and high production cost. Here, we proposed a large-scale biomass gasification system to combine dual fluidized bed and high-temperature gas-cooled reactor (HTR) for co-production of hydrogen and synthetic natural gas (SNG). The design of high-temperature gas-cooled reactor biomass gasification (HTR-BiGas) consists of one steam supply module to heat inlet steam of the gasifier by HTR and ten biomass gasification modules to co-produce 2000 MWth hydrogen and SNG by gasifying the unpretreated biomass. Software for calculating the mass and energy balances of biomass gasification was developed and validated by the experiment results on the Gothenburg biomass gasification plant. The preliminary economic evaluation showed that HTR-BiGas and the other two designs, electric auxiliary heating and increasing recirculated product gas, are economically comparative with present mainstream production techniques and the imported natural gas in China. HTR-BiGas is the best, with production costs of hydrogen and SNG around 1.6 $/kg and 0.43 $/Nm3, respectively. These designs mainly benefit from proper production efficiencies with low fuel-related costs. Compared with HTR-BiGas, electric auxiliary heating is hurt by the higher electric charge and the shortcoming of increasing recirculated product gas is its lower total production. Future works to improve the efficiency and economy of HTR-BiGas and to construct related facilities are introduced. [ABSTRACT FROM AUTHOR]

This study describes the technological processes and characteristics of biomass direct combustion power generation, biomass gasification power generation, biomass mixed combustion power generation, and biomass biogas power generation in terms of their importance and application in China. Under the perspective of environmental and economic sustainability, the life cycle assessment (LCA) method and dynamic analysis method based on time value are used to simulate and evaluate the environmental loads and economic benefits of different power generation processes. By comparing with coal-fired power generation systems, the environmental and economic benefits of different biomass power generation technologies are illustrated. The results shows that biomass gasification power generation has the best environmental benefits, with a total load of 1.05 × 10−5, followed by biomass biogas power generation (9.21 × 10−5), biomass direct combustion power generation (1.23 × 10−4), and biomass mixed combustion power generation (3.88 × 10−4). Compared with the environmental load of coal-fired power generation, the reduction rate was 97.69%, 79.69%, 72.87%, and 14.56% respectively. According to the analysis of the technical economy evaluation results, when the dynamic pay-back period and IRR (internal rate of return) were used as evaluation indicators, the biomass direct combustion power generation has the best pay-back period (7.71 years) and IRR (19.16%), followed by the biogas power generation, with higher dynamic payback period (12.03 years), and lower IRR (13.49%). For gasification power generation and mixed-combustion power generation, their dynamic payback period is long, and the IRR is low. If net present value (NPV) is selected as the evaluation index, the biogas power generation appears to be the best because its net present value per megawatt is 11.94 million yuan, followed by direct combustion power generation (6.09 million yuan), and the net present value of mixed-combustion power generation and gasification power generation is relatively low. Compared with coal-fired power generation, direct combustion power generation and biogas power generation present significant economic benefits. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) gasification could be a novel method that shows the various advantages over traditional MSW treatments in China. Other research concluded that MSW gasification was operating by the assistant heat, and the gasification may occur under medium temperature. So, this study is aimed to investigate MSW gasification and pyrolysis behavior and analyze the syngas evolution and reaction mechanism. The MSW samples were collected in daily life and the experiments were carried out in a fixed tubular reactor below 650 °C. The effects of medium temperature and oxygen content on syngas quality were elucidated in depth. The results have shown that temperature can promote the syngas quality in the range of 550–650 °C, because the increasing temperature strengthens the reaction rate. The oxygen content should be controlled in a certain range, or oxidation reactions will be more prominent during gasification. The optimal gasification condition in this study was obtained at 650 °C and an oxygen concentration of 1.25%, the combustible gas yield and the lower heating value (LHV) of syngas of this condition were 0.296 L/g and 10.98 kJ/L, respectively. This study provides insights for MSW gasification under medium temperature, and a practical gasification system can be designed under a certain condition. [ABSTRACT FROM AUTHOR]