| dc.description.abstract | This study investigated that feasibility of energy yield in co-gasification of sewage sludge (SS) and textile sludge (TS) using a fluidized-bed gasifier under controlled temperature of 850 ℃ and equivalence ratio of 0.2. An integrated hot-gas cleaning system equipped with zeolite, calcined dolomite, and activated carbon was installed and connected with gasifier for removing of trace pollutants produced from co-gasification process. Meanwhile, to further understanding the co-gasification behavior, the thermal degradation kinetic of SS and TS was also discussed using multistep-based determination method.
The kinetic analysis results indicated that the three pseudo reactions occurred in the decomposition of sewage sludge, textile sludge, and their blends using the multistep-based method. Compared to sewage sludge, the activation energy of textile sludge for three consecutive stages varied more widely in the 90-160, 100-190, and 230-320 kJ/mol range, respectively. Although, textile sludge was found harder to decompose, but its presence in a sludge mixture might positively influence sludge co-degradation.
Concerning co-gasification of SS and TS, in the case of TS addition increasing from 15 to 45 wt.%, H2 yield decreased from 2.45 to 2.12 mol/kg as well as CO yield increasing from 2.83 to 3.98 mol/kg. The cold gas efficiency (CGE) of the produced gas in co-gasification was varied in the range of 13.61-14.88 %, whereas the energy yield was found in the range of 2.40-2.63 MJ/kg of dry sludge. However, the energy yield produced from SS gasification was approximately 3.22 MJ/kg. It could observe the higher energy yield generated from SS gasification than that of co-gasification of SS and TS. Regarding tar formation, the TS presence in the feedstock could reduce the relative amount of total tar, especially for the light fraction tar reduction. Therefore, the TS addition increased from 15 to 45 wt.%, it could significantly enhance the gasification performance. A hot-gas cleaning system used in this research presented a considerable performance on tar removal efficiency that reached about 77 % of total tar content as well as removing 90 % heavy fraction tar and 35% ammonia gas in the produced gas.
In summary, co-gasification of sewage and textile sludge was considered as an alternative for simultaneous treating the increasing amount of these sludge and converting sludge-to-energy. Meanwhile, using a hot-gas cleaning system consisting of zeolite, calcined dolomite, and activated carbon would become a good choice for abating the tar and NH3 impurities in producer gas. | en_US |