Thermodynamic analysis of a plasma co-gasification process for hydrogen production using sludge and food waste as mixed raw materials

To solve the problem that sludge and food waste are easy to putrefy and cause secondary pollution to air and groundwater, this work proposes a plasma co-gasification for hydrogen model of sludge and food waste and uses experimental data to verify the model. Based on the simulation results, the effects of plasma gasification temperature and steam to feedstock ratio on the performance of sludge + food waste plasma co-gasification process are discussed by sensitivity analysis. The syngas component characteristics, energy upgrade factor and thermodynamic efficiency of each unit of the two processes are studied. The results show that the hydrogen production capacity of co-gasification process of municipal sludge + food waste is 57.43 % higher than that of the industrial sludge + food waste. The H element content in the raw material is a key factor affecting the hydrogen production in the plasma co-gasification process, while the relative balance of H2 and CO content in crude syngas is conducive to improving the hydrogen production capacity in the entire process. The exergy efficiencies of the two processes are 56.57 % and 56.77 % respectively. This study can provide a new concept for both resource utilization and harmlessness of sludge and food waste treatment.