Sewage and textile sludge co-gasification using a lab-scale fluidized bed gasifier

This research aims to evaluate the hydrogen production and removal ability of impurity (e.g. tar and NH₃) generated from sewage and textile sludge co-gasification using lab-scale fluidized-bed gasifier with an integrated hot-gas cleaning system. The gasification temperature and equivalence ratio (ER) were controlled at 850 °C and 0.2, as well as the hot gas cleaning system operated at 250 °C with the combination of zeolite, calcined dolomite, and activated carbon. Experimental results indicated that the H₂ and CO yield in co-gasification of the tested sludge ranged from 2.12 to 2.45 mol/kg and from 2.83 to 3.98 mol/kg, respectively. The overall energy content of produced gas ranged between 2.40 and 2.63 MJ/kg, and cold gas efficiency (CGE) was nearly 15%. The impurities of produced gas were effectively mitigated by the hot-gas cleaning system, which could remove approximately 90% of the heavy fraction tar, up to 77% of total tar, and about 35% of ammonia. In summary, the combination of the fluidized-bed gasifier and the hot-gas cleaning system had been well developed for purifying the syngas produced from the tested sludge, and it could be applied to other organic wastes in the future.