System design and thermo-economic analysis of municipal solid waste power system integrated with steam dryer

High moisture content of municipal solid waste (MSW) decreases the efficiency of power plant firing MSW directly. The MSW power system integrated with an external steam dryer and waste heat recovery system (WHRS) is proposed to enhance the MSW power plant (MSWP) efficiency. A reference case study with a 12 MW MSWP is carried out. The efficiency of MSWP integrated with a steam dryer can be enhanced by 1.07 percentage points (%-pts) and 0.36%-pts with 0.21 and 1.13 MPa steam extraction, respectively, as dryer heating source at a dryness degree of 0.25. Furthermore, when the WHRS is integrated, the power plant efficiency is enhanced by 1.79%-pts and 1.08%-pts. Then, economic analysis is carried out, and results show that the MSWP can bring profits with the integration of a steam dryer with steam 1.13 MPa steam as heat source at rated degree of dryness.