Establishment And Analysis Of Performance Model Of Biofuel Gasifier

In order to study the performance of a biomass-fed gasifier, a gasification model was established based on chemical equilibrium. In this model, sewage sludge with different water content was used as feedstock. Air was introduced into the gasifier as a gasifying agent. The objectives of the model were (a) calculating the equilibrium temperatures in the gasifier; (b) calculating syngas compositions and heating values at corresponding equilibrium temperatures; (c) finding out the effect of moisture content in the sludge and equivalence ratio on the gasification process; and (d) using a mixed feedstock instead of single feedstock to improve syngas yield. The model was built in MATLAB and Cantera. Elements balance, chemical equilibrium, and enthalpy balance were used in the model. For 1 kg sludge, the moisture contents of sludge range from 0.1 to 0.8, and the equivalence ratios range from 0.5 to 4. The results show that (a) when moisture content = 0.1, ER = 2.47, the CO yield reaches maximum value of 17.548 mol/(kg sludge); (b) when moisture content = 0.1, ER = 2.83, the H 2 yield reaches maximum value of 20.756 mol/(kg sludge). Gasification performance can be improved by mixing sludge with lignite. For 1 kg mixture, the results show that (a) the maximum yield of CO increases from 3.04 to 12.3 mol/(kg mixture) with the increase of lignite content from 10% to 40%; (b) the maximum yield of H-2 increases from 13.75 to 21.88 mol/(kg mixture) with the increase of lignite content from 10% to 40%.