Techno-Economic and Life Cycle Assessment of Pyrolysis of Unsegregated Urban Municipal Solid Waste in India

This work performs detailed techno-economic and life cycle assessment (LCA) of pyrolysis of unsegregated (mixed) municipal solid waste (MSW) in the Indian context. Experimental results of thermal pyrolysis of a representative MSW sample generating char, oil, and gas are used. The proposed process uses gas internally for heating while oil and char are the products. The detailed process flowsheet for a 200 tonnes per day MSW pyrolysis processing plant is developed considering various heat integration and design considerations, and the process is simulated using ASPEN Plus. Experimental results are used to simulate the pyrolysis reactor. The plant is found to be energy sustainable for the moisture content in MSW less than 20% (w/w). The experimental and simulation data are then used to perform economic and LCA. The economic analysis suggests that the process is economically viable with a payback period of 6.17 years and an internal rate of return of 14.33%. However, the economics of the plant is highly sensitive to fluctuation in the installation cost of the reactor, oil collection efficiency, and the selling price of pyrolysis oil. The life cycle climate change impact is 250.4 kg CO2 equiv/tonne of the MSW processed. As compared to open dumping and sanitary landfilling, pyrolysis shows an avoided impact of 989.6 and 593.6 kg CO2 equiv/tonne of MSW, respectively. Based on these results, which are specific to the case study presented, it can be argued that pyrolysis of mixed MSW has potential for scale-up, and must be evaluated for other regions as well.

Automated summary

This study conducts a detailed analysis on the pyrolysis of unsegregated municipal solid waste in India and finds that the process is economically viable and has potential for reducing climate impact compared to traditional waste disposal methods.