Conceptual design and comprehensive analysis for novel municipal sludge gasification-based hydrogen production via plasma gasifier

Abstract Aiming to solve the problems of the environment and land occupied by municipal sludge incineration and landfill technology, novel processes of municipal sludge-to-H2 by plasma gasification and municipal sludge-to-H2 by plasma gasification coupled with synthetic chemical looping processes are proposed to convert municipal sludge into H2 and achieve carbon capture. On the basis of the simulation results, the performance of the two processes was explored through a comprehensive analysis of the process exergy efficiency, economic benefits, and environmental impact. The results show that the novel processes have higher energy conversion and utilization efficiencies. Municipal sludge-to-H2 by the plasma gasification process has notable advantages in production capacity, which is 21.22% higher than that of municipal sludge-to-H2 by plasma gasification coupled with synthetic chemical looping process. However, its exergy efficiency and financial internal rate of return are 6.98% and 4.59%, respectively, which is lower than those of municipal sludge-to-H2 by plasma gasification coupled with synthetic chemical looping. In addition, its total capital investment, global warming potential, and acidification potential are 5.73%, 58.14%, and 16.59% higher than municipal sludge-to-H2 by plasma gasification coupled with synthetic chemical looping. The proposed processes provide promising methods for solving the problems of municipal sludge treatment and the profitable and environmentally sustainable development of municipal sludge into H2.