This work discusses results on temperature profile, syngas composition, High Heating Value, and efficiency of a Coffee Husk counter-current fixed-bed gasification process, in which oxygen-steam blends were used as an oxidizing agent. The experimentation was carried out for various Equivalence Ratios (ER) and Steam-Fuel Ratios (SF), whose ranges were [1.6-5.6] and [0.4-0.8], respectively. The results show that increased steam (higher steam fuel ratios) improves the H 2 /CO molar ratio i.e., for a constant ER = 3.7 and SF at 0.4, 0.6, and 0.8, the H 2 /CO ratio was 1.2, 1.4, and 1.8, respectively. Also, the addition of steam tends to increase the syngas Higher Heating Value, which ranged between 7,714 kJ/m 3 at ER = 1.6 and SF = 0.4 and 8,841 kJ/m 3 at ER = 3.2 and SF = 0.8. On the other hand, increased ER (lower oxygen) decreases the Net Cold Gasification Efficiency (CGE NET) which was between 53% at ER = 5.6 and SF = 0.6 and 82% at ER = 1.6 and SF = 0.4. Results were also compared to results published before for gasification of the same biomass but using air-steam mixtures for partial oxidation. This comparison shows that the use of oxygen increases both the temperature profile in the bed and the yield of CO and H 2 contained in the syngas.
The increasing energy consumption, mostly supplied by fossil fuels, has motivated the research and development of alternative fuel technologies to decrease the humanity's dependence on fossil fuels, which leads to pollution of natural sources. Small-scale biomass gasification, using air-steam blends for partial oxidation, is a good alternative since biomass is a neutral carbon feedstock for sustainable energy generation. This research presents results obtained from an experimental study on coffee husk (CH) gasification, using air-steam blends for partial oxidation in a 10 kW fixed-bed gasifier. Parametric studies on equivalence ratio (ER) (1.53 < ER < 6.11) and steam-fuel (SF) ratio (0.23 < SF < 0.89) were carried out. The results show that increasing both SF and ER results in a syngas rich in CH 4 and H 2 but poor in CO. Also, decreased SF and ER decrease the peak temperature ( peak ) at the gasifier combustion zone. The syngas high heating value (HHV) ranged from 3112 kJ/SATPm 3 to 5085 kJ/SATPm 3 and its maximum value was obtained at SF = 0.87 and ER = 4.09. The dry basis molar concentrations of the species, produced under those operating conditions (1.53 < ER < 6.11 and 0.23 < SF < 0.89), were between 1.12 and 4.1% for CH 4 , between 7.77 and 13.49% for CO, and between 7.54 and 19.07% for H 2 . Other species were in trace amount.
Due to the increase of consumption in the world of energy and the pollution caused by fossil fuel combustion processes, it is necessary to generate new technologies for the use of alternative fuels, allowing to reduce the dependence on fossil fuels such as oil, gas and coal. In general, the combustion processes of fossil fuels produce greenhouse gases which increase the temperature of the environment and the deterioration of the ozone layer. Chemical equilibrium was used to estimate the species produced by adiabatic gasification with different air-vapor mixtures. By running the NASA CEA software (chemical equilibrium with applications), a thermochemical simulation was performed under two parameters: the equivalence ratio (ER) defined as stoichiometric air/air supplied to the reactor (1.5-6) and the steam-fuel ratio (0-1). Thus, the syngas composition showed the following ranges: CO (0% -14.7%), H2 (0% -36.7%), CH4 (0% -4.3%), CO2 (17% -22.7%). The calorific value of the gases and the energy conversion power were also calculated with the composition of the gases. Then, The Higher Heating Value (HHV) was calculated whose values aim to conclude that syngas generated can be classified as a poor fuel gas since the HHV ranged between 1992 kJ/SATP m 3 -7537 kJ/SATP m 3 .
Due to the increase of consumption in the world of energy and the pollution caused by fossil fuel combustion processes, it is necessary to generate new technologies for the use of alternative fuels, allowing to reduce the dependence on fossil fuels such as oil, gas and coal. In general, the combustion processes of fossil fuels produce greenhouse gases which increase the temperature of the environment and the deterioration of the ozone layer. Chemical equilibrium was used to estimate the species produced by adiabatic gasification with different air-vapor mixtures. By running the NASA CEA software (chemical equilibrium with applications), a thermochemical simulation was performed under two parameters: the equivalence ratio (ER) defined as stoichiometric air/air supplied to the reactor (1.5-6) and the steam-fuel ratio (0-1). Thus, the syngas composition showed the following ranges: CO (0% -14.7%), H2 (0% -36.7%), CH4 (0% -4.3%), CO2 (17% -22.7%). The calorific value of the gases and the energy conversion power were also calculated with the composition of the gases. Then, The Higher Heating Value (HHV) was calculated whose values aim to conclude that syngas generated can be classified as a poor fuel gas since the HHV ranged between 1992 kJ/SATP m 3 -7537 kJ/SATP m 3 .
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