Numerical simulation on the fluidized bed gasification and CaO dechlorination of refuse derived fuel

A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel （RDF）. The CaO dechlorination model obtained by the thermal gravity analysis （TGA） is coupled to investigate the process of CaO dechlorination. An Eulerian-Eulerian method is adopted to simulate the gas-solid flow and self-developed chemical reaction modules are used to simulate chemical reactions. Flow patterns, gasification results and dechlorination efficiency are obtained by numerical simulation. Meanwhile, simulations are performed to evaluate the effects of Ca/Cl molar ratio and temperature on dechlorination efficiency. The simulation results show that the presence of bubbles in the gasifier lowers the CaO dechlorination efficiency. Increasing the Ca/Cl molar ratio can enhance the dechlorination efficiency. However, with the temperature increasing, the dechlorination efficiency increases initially and then decreases. The optimal Ca/Cl molar ratio is in the range of 3. 0 to 3. 5 and the optimal temperature is 923K.

Current status of national integrated gasification fuel cell projects in China

Coal has been the main energy source in China for a long period.Therefore,the energy industry must improve coal power generation efficiency and achieve near-zero CO_(2) emissions.Integrated gasification fuel cell(IGFC)systems that combine coal gasification and high-temperature fuel cells,such as solid oxide fuel cells or molten carbonate fuel cells(MCFCs),are proving to be promising for efficient and clean power generation,compared with traditional coal-fired power plants.In 2017,with the support of National Key R&D Program of China,a consortium led by the China Energy Group and including 12 institutions was formed to develop the advanced IGFC technology with near-zero CO_(2) emissions.The objectives of this project include understanding the performance of an IGFC power generation system under different operating conditions,designing master system principles for engineering optimization,developing key technologies and intellectual property portfolios,setting up supply chains for key materials and equipment,and operating the first megawatt IGFC demonstration system with near-zero CO_(2) emission,in early 2022.In this paper,the main developments and projections pertaining to the IGFC project are highlighted.

Solid oxide fuel cells in combination with biomass gasification for electric power generation

Biomass,a source of renewable energy,represents an effective substitute to fossil fuels.Gasification is a process that organics are thermochemically converted into valuable gaseous products(e.g.biogas).In this work,the catalytic test demonstrated that the biogas produced from biomass gasification mainly consists of H2,CH4,CO,and CO2,which were then be used as the fuel for solid oxide fuel cell(SOFC).Planar SOFCs were fabricated and adopted.The steam reforming of biogas was carried out at the anode of a SOFC to obtain a hydrogen-rich fuel.The performance of the SOFCs operating on generated biogas was investigated by I-V polarization and electrochemical impedance spectra characterizations.An excellent cell performance was obtained,for example,the peak power density of the SOFC reached 1391 mW·cm-2 at 750℃when the generated biogas was used as the fuel.Furthermore,the SOFC fuelled by simulated biogas delivered a very stable operation.

Experiments on Ni/γ-Al_2O_3 catalyst for improving lower heating value of biomass gasification fuel gas via methanation

Ni-based catalysts supported by γ-Al_2O_3 were prepared for improving the lower heating value( LHV) of biomass gasification fuel gas through methanation. Prior to the performance tests, the physico-chemical properties of the catalyst samples were characterized by N_2 isothermal adsorption/desorption, X-ray diffraction( XRD) and a scanning electron microscope( SEM). Afterwards, a series of experiments were carried out to investigate the catalytic performance and the results showthat catalysts with 15% and20% Ni loadings have better methanation catalytic effect than those with 5% and 10% Ni loadings in terms of elevating the LHV of biomass gasification fuel gas. M oreover, controllable influential factors such as the reaction temperature, the H_2/CO ratio and the water content occupy an important position in the methanation of biomass gasification fuel gas. 15 Ni/γ-Al_2O_3 and 20 Ni/γ-Al_2O_3 catalysts have a higher CO conversion and CH_4 selectivity at 350 ℃ and the LHV of biomass gasification fuel gas can be largely increased by 34. 3 % at 350 ℃. Higher H_2/CO ratio and a lower water content are more beneficial for improving the LHV of biomass gasification fuel gas when considering the combination of both CO conversion and CH_4 selectivity. This is due to the fact that a higher H_2/CO ratio and lower water content can increase the extent of the methanation reaction.

The Control of Lactobacillus sp.by Extracellular Compound Produced by Pseudomonas aeruginosa in the Fermentation Process of Fuel Ethanol Industry in Brazil

This work evaluated the effect of secondary bacterial metabolites produced by Pseudomonas sp LV strain in control of Lactobacillus sp. population in the microcosm of the vat during ethanol fermentation. The fraction F4 produced by Pseudomonas aeruginosa was extracted with dichloromethane and fractionating by vacuum liquid chromatography obtained in a methanol phase. The evaluation of antibiotic activity of F4 fraction mixed or not with sulphuric acid and Kamoram?. The antibiotic activity of F4 fraction was determined as well as the fermentation efficiency. Also was determined yeast cell viability, budding formation, the viability of budding cells, and number of populations of Saccharomyces cerevisiae and Lactobacillus sp. The results showed that the F4 fraction had high selective antibiotic activity against Lactobacillus sp. but not for S. cerevisae, and no inhibitory effect was observed in the fermentation process by yeast. Also F4 fraction decreased flocculation and foam formation. The F4 has an antibiotic activity against Lactobacillus sp. and should be used as an alternative to control bacteria contamination and foam and flocculation formation in the fuel ethanol fermentation process. The F4 fraction could reduce the use of antibiotics in the control of Lactobacillus sp. population during the fuel ethanol production.

Sorghum as Dry Land Feedstock for Fuel Ethanol Production

Dry land crops such as sorghums （grain sorghum, promising feedstocks for fuel ethanol production. The major issue sweet sorghum and forage sorghum） have been identified as for using the sweet sorghum as feedstock is its stability at room temperature. At room temperature, the sweet sorghum juice could lose from 40% to 50% of its fermentable sugars from 7 to 14 days No significant sugar content and profile changes were observed in juice stored at refrigerator temperature in two weeks. Ethanol fermentation efficiencies of fresh and frozen juice were high （-93%）. Concentrated juice （≥25% sugar） had significantly lower efficiencies and large amounts of fructose left in finished beer; however, winery yeast strains and novel fermentation techniques may solve these problems. The ethanol yield from sorghum grain increased as starch content increased. No linear relationship between starch content and fermentation efficiency was found. Key factors affecting the ethanol fermentation efficiency of sorghum include starches and protein digestibility, amylose-lipid complexes, tannin content, and mash viscosity. Life cycle analysis showed a positive net energy value （NEV） = 25 500 Btu/gal ethanol. Fourier transform infrared （FTIR） spectroscopy and X-ray diffraction （XRD） were used to determine changes in the structure and chemical composition of sorghum biomasses. Dilute sulfuric acid pretreatment was effective in removing the hemicellulose from biomasses and exposing the cellulose for enzymatic hydrolysis. Forage sorghum lignin had a lower syringyl/guaiacyl ratio and its pretreated biomass was easier to hydrolyze. Up to 72% hexose yield and 94% pentose yield were obtained by using a modified steam explosion with 2% sulfuric acid at 140℃ for 30 min and enzymatic hydrolysis with cellulase.

Status of an MWth integrated gasification fuel cell powergeneration system in China

Abstract Here,we provide a status update of an integrated gasification fuel cell(IGFC)power-generation system being developed at the National Institute of Clean-and-Low-Carbon in China at the megawatt thermal(MWth)scale.This system is designed to use coal as fuel to produce syngas as a first step,similar to that employed for the integrated gasification combined cycle.Subsequently,the solid-oxide fuel-cell(SOFC)system is used to convert chemical energy to electricity directly through an electrochemical reaction without combustion.This system leads to higher efficiency as compared with that from a traditional coal-fired power plant.The unreacted fuel in the SOFC system is transported to an oxygencombustor to be converted to steam and carbon dioxide(CO_(2)).Through a heat-recovery system,the steam is condensed and removed,and CO_(2) is enriched and captured for sequestration or utilization.Comprehensive economic analyses for a typical IGFC system was performed and the results were compared with those for a supercritical pulverized coal-fired power plant.The SOFC stacks selected for IGFC development were tested and qualified under hydrogen and simulated coal syngas fuel.Experimental results using SOFC stacks and thermodynamic analyses indicated that the control of hydrogen/CO ratio of syngas and steam/CO ratio is important to avoid carbon deposition with the fuel pipe.A 20-kW SOFC unit is under development with design power output of 20 kW and DC efficiency of 50.41%.A 100 kW-level subsystem will consist of 6920-kW power-generation units,and the MWth IGFC system will consist of 59100 kWlevel subsystems.

Allocation of Energy Use in the Biomass-based Fuel Ethanol System and Its Use in Decision Making

The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The energy efficiency of the biomass-based fuel ethanol is critical issue. To investigate the energy use in the three biomass-base ethanol fuel systems, energy content approach, Market value approach and Product displacement approach methods were used to allocate the energy use based on life cycle energy assessment. The results shows that the net energy of corn based, wheat based, and cassava-based ethanol fuel are 12543MJ, 10299MJ and 13112MJ when get one ton biomassbased ethanol, respectively, and they do produce positive net energy.

Hainan to invest 350 million Yuan in fuel ethanol projects

Hainan Yedao (Group) Co. Ltd. plans to invest 350 million Yuan in construction of a fuel ethanol project. With cooperation of a large state-owned petrochemical enter- prise, this project is planned to produce 100 thousand

Simulation of Fuel Ethanol Production from Lignocellulosic Biomass

Models for hydrolysis,fermentation and concentration process,production and utilization of biogas as well as lignin gasification are developed to calculate the heat demand of ethanol production process and the amounts of heat and power generated from residues and wastewater of the process.For the energy analysis,all relevant information about the process streams,physical properties,and mass and energy balances are considered.Energy integration is investigated for establishing a network of facilities for heat and power generation from wastewater and residues treatment aiming at the increase of energy efficiency.Feeding the lignin to an IGCC process,the electric efficiency is increased by 4.4% compared with combustion,which leads to an overall energy efficiency of 53.8%.A detailed sensitivity analysis on energy efficiency is also carried out.

Simulation study on the gasification process of Ningdong coal with iron-based oxygen carrier

Chemical looping gasification(CLG) of Ningdong coal by using Fe_(2) O_(3) as the oxygen carriers(OCs) was studied,and the gasification characteristics were obtained.A computation fluid dynamics(CFD) model based on Eulerian--Lagrangian multiphase framework was established,and a numerical simulation the coal chemical looping gasification processes in fuel reactor(FR) was investigated.In addition,the heterogeneous reactions,homogeneous reactions and Fe_(2) O_(3) oxygen carriers' reduction reactions were considered in the gasification process.The characteristics of gas flow and gasification in the FR were analyzed and it was found that the experiment results were consistent with the simulation values.The results show that when the O/C mole rate was 0.5:1,the gasification temperature was 900℃ and the water vapor volume flow rate was 2.2 ml·min^(-1),the mole fraction of syngas reached a maximum value of the experimental result and simulation value were 71.5% and 70.2%,respectively.When the O/C mole rate was 0.5:1,the gasification temperature was 900℃,and the water vapor volume flow was 1.8 ml·min^(-1);the gasification efficiency reached the maximum value was 62.2%,and the maximum carbon conversion rate was 84.0%.

Co-gasification of coal and biomass an emerging clean energy technology: Status and prospects of development in Indian context

Co-gasification of coal and biomass is emerging as potential clean fuel technology to achieve high thermodynamic efficiency with relatively low CO2 emission. The coal and biomass have been exclusively gasified more than a century to obtain gas–liquid fuels and the production of chemicals. Co-gasification has higher efficiency than the solitary coal gasification because the cellulose, hemicellulose and lignin content of biomass help to ignite and enhance the rate of gasification. It is suggested that the extensive research on carbon reactivity pattern, heat release, reaction kinetics, etc. may support to reduce the uncertainties in the co-gasification performance of coal and biomass blends, particularly in India. The prospects of co-gasification technology in Indian context have been discussed considering the abundance of varieties of coal and biomass. The suitability of existing gasifier procedures and their limitations with operating parameters like temperature, residence time, density optimisation, feed rate, agglomeration intensity, the tar formation and techno-economics involved are described. Also, this paper reviews the research highlights of the history of co-gasification and the advancement in upcoming challenges like a design of gasifier, access and preparation of biomass, disposal of residue, environmental concerns and reassurance to the operators for execution of large and small-scale projects.

Syngas production via coal char-CO_2 fluidized bed gasification and the effect on the performance of LSCFN//LSGM//LSCFN solid oxide fuel cell

Fluidized bed reactor is widely used in coal char-CO2 gasification. In this work, the production of syngas by using a fluidized bed gasification technique was first investigated and then the effect of the produced syngas on the performance of the solid oxide fuel cell with a configuration of La0.4Sr0.6Co0.2 Fe0.7 Nb0.1O3-δ//La0.8Sr0.2Ga0.83Mg0.17O3-δ//La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ（LSCFN//LSGM//LSCFN） was studied. During the syngas production, we found that the volume fraction of CO increased with the increment of gasification temperature, and it reached a maximum value of 88.8%, corresponding to a composition of 0.76% H2, 88.8% CO, and 10.44% CO2, when the ratio of oxygen mass flow rate to that of coal char （Mo2/Mchar） increased to 0.29. In the following utilization of the produced syngas in solid oxide fuel cells, it was found that the increasing CO volume fraction in the syngas results in a gradual increase of the peak power density of the LSCFN//LSGM//LSCFN cell. The maximum peak power density of 410 mW/cm^2 was achieved for the syngas produced at 0.29 of Mo2/Mchar. In the stability test, the cell voltage decreased by 4% at a constant current density of 0.475 A/cm^2 after 54 h when fueled with the syngas with the composition of 0.76% H2, 88.8% CO, and 10.44% CO2. It reveals that a carbon deposition with the content of 13.66% in the anode is attributed to the cell performance degradation.

Preparation and emission characteristics of ethanol-diesel fuel blends

The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection(DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon(HC), and carbon monoxide(CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas.

Preparation and characterization of Pt-WO_3/C catalysts for direct ethanol fuel cells

Three co-impregnation/chemical reduction methods in acidic solutions of pH 〈 1,including ethylene glycol （EG）,NaBH4,and HCOOH,were compared for Pt-WO3/C catalysts.Pt-WO3/C catalysts containing 10 wt.% and 20 wt.% platinum per carbon were prepared by the three methods; their morphology and electrocatalytic activities were characterized.The 20 wt.% Pt-WO3/C catalyst prepared by the co-impregnation/EG method presented the optimal dispersion with an average particle size of 4.6 nm and subsequently the best electrocatalytic activity,and so,it was further characterized.Its anodic peak current density for ethanol oxidation from linear sweep voltammetry （LSV） is 7.9 mA·cm^-2,which is 1.4 and 5.2 times as high as those of the catalysts prepared by co-impregnation/NaBH4 and co-impregnation/ HCOOH reduction methods,2.1 times as high as that of the 10 wt.% Pt-WO3/C catalyst prepared by co-impregnation/EG method,respectively.

Synthesis and characterization of Pt-MoO_x-TiO_2 electrodes for direct ethanol fuel cells

To enhance the CO-tolerance performance of anode catalysts for direct ethanol fuel cells,carbon nanotubes were modified by titanium dioxide （donated as CNTs@TiO2） and subsequently served as the support for the preparation of Pt/CNTs@TiO2 and Pt-Mo/CNTs@TiO2 electrocatalysts via a UV-photoreduction method.The physicochemical characterizations of the catalysts were carried out by using X-ray diffraction （XRD）,transmission electron microscopy （TEM）,X-ray photoelectron spectroscopy （XPS）,and infrared spectroscopy of adsorbed probe ammonia molecules.The electrocatalytic properties of the catalysts for methanol oxidation were investigated by the cyclic voltammetry technique.The results show that Pt-Mo/CNTs@TiO2 electrode exhibits the highest performance in all the electrodes.It is explained that,the structure,the oxidation states,and the acid-base properties of the catalysts are influenced due to the strong interaction between Ti and Mo species by adding TiO2 and MoOx to the Pt-based catalysts.

A Novel Routine for Manufacture of Environmentally Friendly Ethanol Fuel via Reactive Distillation

A novel routine for removing water from ethanol by the hydration using C4 olefin cut catalyzed with the ion exchange resin was proposed. Reactive distillation experiments were carried out to demonstrate the feasibility of this routine. The sensitivity analysis was performed by using the software of ASPEN PLUS 10.2. The optimized operating conditions were obtained considering three objective functions which were the water content of the bottom product, water conversion rate and hydration selectivity. Under the optimized operation conditions, the final product was consisted of 45.0% of ethanol, 19.4% of ethyl tert-butyl ether, 35.1% of tert-butyl alcohol and 0.6% of water in volumetric percentage.

Uncertainty in life cycle economical analysis of cassava-based ethanol fuel

Biomass ethanol fuel is not only renewable but also environmental-friendly. Guangxi Zhuang Autonomous Region is developing the cassava-based ethanol fuel. Economical performance of the project is the key issue. The traditional life cycle economical analysis is just a static calculation process. Uncertainty is the character of cassava yield, cost of cassava plant, cassava price, tax rate and gasoline price, and the economical performance of the project is determined by these aspects. This study proposes an economical model of cassava-based ethanol fuel. The method of Monte Carol is used to simulate the economical performance. This method conquers the shortage of the traditional way. The results show that cassava-based ethanol fuel can get survived when the tax is exempted. Finally, the study also evaluates the potential of the economical performance.

Decision-making of biomass ethanol fuel policy based on life cycle 3E assessment

To evaluate the environmental, economic, energy performance of biomass ethanol fuel in China and to support the decision-making of biomass ethanol energy policy, an assessment method of life cycle 3E (economy, environment, energy) was applied to the three biomass ethanol fuel cycle alternatives, which includes cassava-based, corn-based and wheat-based ethanol fuel. The assessments provide a comparison of the economical performance, energy efficiency and environmental impacts of the three alternatives. And the development potential of the three alternatives in China was examined. The results are very useful for the Chinese government to make decisions on the biomass ethanol energy policy, and some advises for the decision-making of Chinese government were given.

Miscibility of Ethanol in Diesel Fuels

The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testing their phase separation temperatures. The result shows that aromatic contents and intermediate distillate temperatures have a significant impact on miscibility limits. The FCC diesels, which contain up to 50% of aromatics, exhibit different phase behavior trends in comparison with straight-run diesels and other diesel fuels.