Design and Performance Evaluation of Integrating the Waste Heat Recovery System (WHRS) for a Silicon Arc Furnace with Plasma Gasification for Medical Waste

Abstract

A hybrid scheme integrating the current waste heat recovery system (WHRS) for a silicon arc furnace with plasma gasification for medical waste is proposed. Combustible syngas converted from medical waste is used to drive the gas turbine for power generation, and waste heat is recovered from the raw syngas and exhaust gas from the gas turbine for auxiliary heating of steam and feed water in the WHRS. Meanwhile, the plasma gasifier can also achieve a harmless disposal of the hazardous fine silica particles generated in polysilicon production. The performance of the proposed design is investigated by energy, exergy, and economic analysis. The results indicate that after the integration, medical waste gave rise to 4.17 MW net power at an efficiency of up to 33.99%. Meanwhile, 4320 t of the silica powder can be disposed conveniently by the plasma gasifier every year, as well as 23,040 t of medical waste. The proposed design of upgrading the current WHRS to the hybrid system requires an initial investment of 18,843.65 K$ and has a short dynamic payback period of 3.94 years. Therefore, the hybrid scheme is feasible and promising for commercial application.

Thermal Destruction of Waste and the Impact of the Presence of Cl and S in Waste on the Emissions of Cu, Ni, and Pb and Their Immobilisation in the Ash Residue

“…Many types of waste, e.g., some hazardous waste, including medical waste, animal waste, fuels from waste, and some industrial waste must be neutralised in high-temperature thermal processes-e.g., incineration, plasma processes. The thermal transformation of waste includes waste incineration, alternative technologies to waste incineration and coincineration of waste with conventional fuels [1][2][3][4][5]. Waste incineration is by far the most widely method used in the world.…”