Technical and Economic Aspects of Hot Syngas Purification for Power Generation from Gasification of Municipal Solid Waste

Gasification is an advanced thermochemical process, which can convert municipal solid waste (MSW) into gaseous fuel (syngas) for utilization in solid oxide fuel cells (SOFCs), gas engines, combined cycle gas turbines (CCGTs) and/or hybrid systems with potentially higher electrical efficiency and lower emission of pollutants. However, this requires the development of cost-efficient syngas purification technologies that are able to remove particulates, tar, HCl, alkali chlorides and sulphur species at high temperatures. The objective of this study was to investigate the technical feasibility and cost benefit analysis of hot syngas treatment using a multi-stage purification process. To achieve these goals, a syngas purification system (5 L/min syngas treatment capacity) was integrated with a lab-scale downdraft gasifier operating on refuse-derived fuel (RDF). RDF pellets were gasified at 850 °C with equivalence air ratio of 0.3 and 25% moisture content to produce syngas with consistent properties. The technical feasibility of the purification process of the raw syngas was evaluated with the focus on the performance of fluidized bed tar reforming (850 °C) and syngas desulfurization (400 °C). Cost effectiveness and energy efficiency of the developed system were analysed using simulated models (ASPEN Plus^®). Hot syngas purification is demonstrated to be technically feasible based on the experimental results and economically feasible based on the modeling results.