Influence of Internal Baffles on Mixing Characteristics of Biomass in a Fluidized Sand Bed

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): Influence of Internal Baffles on Mixing Characteristics of Biomass in a Fluidized Sand Bed. Manuscript EE 06 016. Vol. IX. April, 2007

Fluidization Characteristics of Sand and Chopped Switchgrass-Sand Mixtures

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 7 (2005): Fluidization Characteristics of Sand and Chopped Switchgrass-Sand Mixtures by K. N. Patil, T. J. Bowser, D. D. Bellmer, R. L. Huhnk

Effects of Syngas Cooling and Biomass Filter Medium on Tar Removal

Biomass gasification is a proven technology; however, one of the major obstacles in using product syngas for electric power generation and biofuels is the removal of tar. The purpose of this research was to develop and evaluate effectiveness of tar removal methods by cooling the syngas and using wood shavings as filtering media. The performance of the wood shavings filter equipped with an oil bubbler and heat exchanger as cooling systems was tested using tar-laden syngas generated from a 20-kW downdraft gasifier. The tar reduction efficiencies of wood shavings filter, wood shavings filter with heat exchanger, and wood shavings filter with oil bubbler were 10%, 61%, and 97%, respectively

Mobile Power Generation From Co-Gasification of Municipal Solid Waste (MSW) and Switchgrass

This presentation was given during the Syngas Technologies Conference

Tar Reduction in Biomass Syngas Using Heat Exchanger and Vegetable Oil Bubbler

A heat exchanger and vegetable oil bubbling system was designed and tested for biomass-generated syngas cooling and cleaning. The fully enclosed heat exchanger contained water at 15 °C, with syngas having to travel 35 m3/s. Using canola oil, the bubbler was tested at 70 and 100 mm oil depths and 5 and 10 mm syngas bubble sizes to determine the effect of tar removal. The results showed that tar removal efficiency was significantly affected by oil depth and bubble size; however, the interaction between bubble size and oil depth was not significant. About 60% of tars was removed by the heat exchanger alone and 96% of the remaining tars was removed by the oil bubbler when used in series with the heat exchanger. Overall, tar reduction efficiency of 98.5% was achieved with the heat exchanger plus oil bubbler having oil depth of 100 mm and syngas bubble size of 5 mm. Heat exchanger removed most of the tars by cooling the syngas below its dew point but syngas tars with low dew point was absorbed in the oil bubbler

Engine Power Generation and Emission Performance of Syngas Generated From Low-Density Biomass

The power production from renewable sources must increase to meet the growing demand of power across the globe on a sustainable basis. Unlike most of gasification works that use high density biomass (e.g. wood chips) to generate a high quality syngas, here we introduce a novel gasification system that can use underutilized low density biomass resources to produce power and electricity with high efficiency yet minimum set-up requirement and low emissions. Switchgrass, one of locally abundant and low density biomass, was used as the biomass feedstock. A unique pilot-scale patented gasifier with a cyclonic combustion chamber having a capacity of 60 kW was used. A commercial natural gas – based, spark-ignition (SI) engine with capacity of 10 kW was modified to measure and control air-fuel ratio and fed with the syngas produced directly from the gasifier. The engine load was regulated by an electric load bank to evaluate the engine operational characteristics. The natural gas was used as the reference feed to evaluate the engine and emissions performance. Gas composition and flowrate, output power, electrical efficiency, and exhaust emissions such as CO2, CO, NOx, SO2, and hydrocarbons were measured. Net electrical efficiency of 21.3% and specific fuel consumption (SFC) of 1.9 kg/kWh were achieved while producing 5 kW at the maximum load using syngas, while 22.7% of electrical efficiency and 0.3 kg/kWh of SFC were achieved using natural gas at the equivalent load. NOx and HC emission produced from the engine was significantly affected by the gas fed and the load applied. CO2 emission varied moderately yet significantly with the increasing load, while CO and SO2 emissions did not strongly influenced by the load variation. NOx emission was 21.5 ppm that complies with the California emission standard limit (25.9 ppm). The study results showed that with minimum set-up, the downdraft gasification system coupled with existing commercial natural gas-based spark-ignited (SI) engine can satisfactorily generate sustainable power supply with high efficiency and minimum emissions to support off-grid power application

Critical factors affecting the integration of biomass gasification and syngas fermentation technology

Gasification-fermentation is a thermochemical-biological platform for the production of fuels and chemicals. Biomass is gasified at high temperatures to make syngas, a gas composed of CO, CO2, H2, N2 and other minor components. Syngas is then fed to anaerobic microorganisms that convert CO, CO2 and H2 to alcohols by fermentation. This platform offers numerous advantages such as flexibility of feedstock and syngas composition and lower operating temperature and pressure compared to other catalytic syngas conversion processes. In comparison to hydrolysis-fermentation, gasification-fermentation has a major advantage of utilizing all organic components of biomass, including lignin, to yield higher fuel production. Furthermore, syngas fermentation microorganisms do not require strict CO:H2:CO2 ratios, hence gas reforming is not required. However, several issues must be addressed for successful deployment of gasification-fermentation, particularly those that involve the integration of gasification and fermentation. Most previous reviews have focused only on either biomass gasification or syngas fermentation. In this review, the critical factors that affect the integration of biomass gasification with syngas fermentation, such as carbon conversion efficiency, effect of trace gaseous species, H2 to CO ratio requirements, and microbial preference of carbon substrate, are thoroughly discussed

Critical factors affecting the integration of biomass gasification and syngas fermentation technology

Gasification-fermentation is a thermochemical-biological platform for the production of fuels and chemicals. Biomass is gasified at high temperatures to make syngas, a gas composed of CO, CO2, H2, N2 and other minor components. Syngas is then fed to anaerobic microorganisms that convert CO, CO2 and H2 to alcohols by fermentation. This platform offers numerous advantages such as flexibility of feedstock and syngas composition and lower operating temperature and pressure compared to other catalytic syngas conversion processes. In comparison to hydrolysis-fermentation, gasification-fermentation has a major advantage of utilizing all organic components of biomass, including lignin, to yield higher fuel production. Furthermore, syngas fermentation microorganisms do not require strict CO:H2:CO2 ratios, hence gas reforming is not required. However, several issues must be addressed for successful deployment of gasification-fermentation, particularly those that involve the integration of gasification and fermentation. Most previous reviews have focused only on either biomass gasification or syngas fermentation. In this review, the critical factors that affect the integration of biomass gasification with syngas fermentation, such as carbon conversion efficiency, effect of trace gaseous species, H2 to CO ratio requirements, and microbial preference of carbon substrate, are thoroughly discussed

Critical factors affecting the integration of biomass gasification and syngas fermentation technology

Gasification-fermentation is a thermochemical-biological platform for the production of fuels and chemicals. Biomass is gasified at high temperatures to make syngas, a gas composed of CO, CO2, H2, N2 and other minor components. Syngas is then fed to anaerobic microorganisms that convert CO, CO2 and H2 to alcohols by fermentation. This platform offers numerous advantages such as flexibility of feedstock and syngas composition and lower operating temperature and pressure compared to other catalytic syngas conversion processes. In comparison to hydrolysis-fermentation, gasification-fermentation has a major advantage of utilizing all organic components of biomass, including lignin, to yield higher fuel production. Furthermore, syngas fermentation microorganisms do not require strict CO:H2:CO2 ratios, hence gas reforming is not required. However, several issues must be addressed for successful deployment of gasification-fermentation, particularly those that involve the integration of gasification and fermentation. Most previous reviews have focused only on either biomass gasification or syngas fermentation. In this review, the critical factors that affect the integration of biomass gasification with syngas fermentation, such as carbon conversion efficiency, effect of trace gaseous species, H2 to CO ratio requirements, and microbial preference of carbon substrate, are thoroughly discussed