Formate gradients as a means for detecting the maximum carbon conversion efficiency of heterotrophic substrates: Correlation between formate utilization and biomass increase

Biomass energy via gasification is an attractive substitute of fossil fuels. The distribution of biomass on the earth is scattered, so transportation and collection of biomass complicates the supply of biomass especially when the gasification rely on one type of biomass. Therefore, cogasification of different biomass is proposed as a potential solution for interruption-free gasification. Beside, unwanted by-products such as tar that cause blockage in downstream equipment can be minimized through the use of catalyst in gasification to accelerate tar reforming process. In this study, catalytic co-gasification of blended feedstock of 70% wood chips and 30% coconut fronds was carried out in a downdraft gasifier using limestone as primary catalyst. The effects of catalyst loading (0%, 30%, 50%, and 70% w/w) on syngas composition, gas yield, carbon conversion efficiency and heating value of syngas were investigated. The results showed that at 50% biomass to catalyst ratio, maximum H2 content of 11.39%, CO of 17.88%, carbon conversion efficiency of 69.49%, gas yield of 1.68 Nm3/kg and higher heating value of syngas 5.11 MJ/Nm3 were achieved. Higher catalyst loading (70%) blocked the air passage, which caused poor gasification. No more than 50% catalyst suggested for stable co-gasification operation.

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Carbon conversion efficiency and central metabolic fluxes in developing sunflower (Helianthus annuus L.) embryos

The Plant Journal ◽

10.1111/j.1365-313x.2007.03235.x ◽

2007 ◽

Vol 52 (2) ◽

pp. 296-308 ◽

Cited By ~ 105

Author(s):

Ana P. Alonso ◽

Fernando D. Goffman ◽

John B. Ohlrogge ◽

Yair Shachar-Hill

Keyword(s):

Helianthus Annuus ◽

Conversion Efficiency ◽

Carbon Conversion ◽

Helianthus Annuus L ◽

Metabolic Fluxes

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Syngas Production from Microwave Gasification of Oil Palm Biochars

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.695.247 ◽

2014 ◽

Vol 695 ◽

pp. 247-250 ◽

Cited By ~ 3

Author(s):

Norasyikin Ismail ◽

Farid Nasir Ani

Keyword(s):

Conversion Efficiency ◽

Oil Palm ◽

Carbon Conversion ◽

Carbonaceous Materials ◽

Test Rig ◽

Heating Value ◽

Syngas Production ◽

Oil Palm Shell ◽

Gas Heating ◽

Gas Volume

Gasification is a reaction process between solid or liquid carbonaceous materials with some gasifying agent to produce gaseous fuel. In this study, a microwave gasification test rig is designed to produce syngas from oil palm biochars. Carbon dioxide is used as the gasifying agent. Oil palm empty fruit bunch (EFB) and oil palm shell (OPS) biochars are used as the carbonaceous materials. The effects of CO2 flow rates on the type of biochars to the syngas produced are investigated. The optimum CO2 flow rate for EFB biochar gasification is 3 lpm where the gas compositions are 0.52% CH4, 50.52% CO2, 26.1% CO, and 22.86% H2. For OPS biochar, the optimum CO2 flowrate is 2 lpm that produce 6.92% CH4, 57.19% CO2, 10.98% CO, and 24.92% H2. For EFB biochar gasification, the specific volume of gas yield is from 1.22 to 1.51 m3/kg while for OPS biochar yields higher specific gas volume, ranging from 2.62 to 7.88 m3/kg. The highest carbon conversion efficiency and gas heating value for EFB biochar is 75.07% and 12.84 MJ/kg at 3 lpm respectively and 66.83%, 13.03 MJ/kg at 2 lpm for OPS biochar respectively . This concludes that EFB biochar produced higher quality syngas than OPS biochar because of the higher volume of CO and H2 content in the syngas produced at the higher carbon conversion efficiency with specific gas volume of 1.22 m3/kg.

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Size-Segregated Particulate Matter from Gasification of Bulgarian Agro-Forest Biomass Residue

Energies ◽

10.3390/en14020385 ◽

2021 ◽

Vol 14 (2) ◽

pp. 385

Author(s):

Ricardo Ferreira ◽

Tsvetelina Petrova ◽

Ana F. Ferreira ◽

Mário Costa ◽

Iliyana Inaydenova ◽

...

Keyword(s):

Particulate Matter ◽

Conversion Efficiency ◽

Forest Biomass ◽

Drop Tube ◽

Xps Analysis ◽

Carbon Conversion ◽

Submicron Size ◽

Gasification Process ◽

Lower Heating Value ◽

Cold Gas

The main purpose of the present work was to evaluate the efficiency of the gasification process of three different types of agro-forest biomass residue (rapeseed, softwood, and sunflower husks) along with the characterization of size-segregated particulates’ emissions. The experiments were carried out in a drop tube furnace (DTF), using two different gasifying agents (O2/N2 and O2/N2/CO2) at atmospheric pressure and a constant temperature of 1000 °C. In focus was the effect of biomass and the gasifying agent on syngas composition (CO, H2, CH4, and CO2), cold gas and carbon conversion efficiency, and on the emissions of by-products, such as particulate matter (PM), known for having negative environmental and health impacts. The collected particulates were characterized by SEM/EDS and XPS analysis. The results reveal that: (i) the introduction of CO2 increased the production of CO and CH4 and syngas’ lower heating value (LHV), thus leading to higher cold gas and carbon conversion efficiency; (ii) CO2 decreased the production of H2, leading to lower H2/CO ratio (between 0.25 and 0.9). Therefore, the generated syngas is suitable for the synthesis of higher hydrocarbons, (iii) CO2 lowered the emissions of char (cyclone) particles but increased the overall PM10–0.3. Submicron size PM was the dominant fraction (PM1–0.3) in O2/N2 and (PM1.6–0.3) in O2/N2/CO2. Unimodal PM size distribution was observed, except for sunflower husks gasification in O2/N2/CO2; (iv) the SEM/EDS and XPS analysis confirmed that submicron-sized PM1–0.3 contain above 80% of carbon associated to soot, due to incomplete oxidation, whereas in cyclone (char) particles, carbon decreased to about 50%. The SEM/EDS results showed that K and Cl are typical constituents of the submicron size PM, whereas the alkaline earth metals were detected mainly in fine and coarse particulates. Detailed analysis of the XPS (C1s) spectra showed that the most common oxygen-containing groups on the PM1 surface were carbonyl and carboxyl.

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