A novel integration of plasma gasification melting process with direct carbon fuel cell

Abstract

As municipal solid waste (MSW) is a low-cost, available, and basically renewable source, energy recovery from MSW is a beneficial technique for reducing fossil fuel usage while also lowering MSW disposal challenges. The current study proposes a novel scheme consisting of plasma gasification melting (PGM) process and direct carbon fuel cell (DCFC) system for converting MSW into high-quality syngas and power. Plasma air and high-temperature steam are employed in the process as gasification agents. The DCFC runs on the pyrolysis char, which is a carbon-rich source and is extracted during the PGM process and sent to the DCFC. The process is simulated in Aspen Plus, and a computational model for estimating the DCFC's output voltage and power is developed in MATLAB. Effects of main operating parameters, including equivalence ratio, steam to biomass ratio, plasma energy ratio, char separation fraction, and fuel cell operating temperature on the system's performance indicators, namely syngas composition, syngas lower heating value, syngas yield, gasification temperature, overall efficiency, and DCFC power output were investigated. By increasing the char separation fraction, more pyrolysis char was extracted and forwarded to the DCFC, which leads to less amount of char entering the gasification section and higher power output through the DCFC. Keeping other parameters constant, at a fuel cell operating temperature of 923 K, the optimal value for char extraction fraction was 0.15, resulting in a 79.5% overall efficiency.