Abstract: With increasingly stringent emission standards and requirements for co-combustion of industrial solid waste, traditional deacidification processes face challenges such as high operational load, low lime utilization efficiency, increased fly ash generation, and tightening emission compliance pressures. This study established a three-stage collaborative acid gas removal system (furnace dry process + semi-dry process + wet process) by integrating a furnace dry process into the existing flue gas treatment process. The coupling performance was systematically investigated by dynamically adjusting the calcium-to-sulfur ratio (Ca/S). Results showed that the removal efficiencies of SO2 and HCl by the furnace dry process increased with rising Ca/S, reaching 89% and 66%, respectively, at Ca/S=1.52. Reasonable control of Ca/S (0.8-1.0) reduced the subsequent semi-dry process slurry volume and wet process alkali solution consumption, while decreasing system fly ash generation (fly ash rate reduced from 2.68% to 2.33%) and total acid gas removal costs. Taking the in-furnace dry process injection volume of 200 kg/h of desulfurizer as an example, the operational cost for acid gas removal per ton of waste decreased by 1.12 yuan, with daily fly ash disposal costs reduced by 9 908 yuan. This study demonstrates that the furnace dry process, as a front-end technology, achieves integrated “waste reduction, cost reduction, and efficiency enhancement” through high-temperature rapid reactions and collaboration with back-end processes,while ensuring compliance with emission standards. It provides an efficient and economical flue gas treatment solution for waste incineration plants co-incinerating industrial solid waste.

Key words: 　waste incineration furnace, in-furnace dry process, ultra-low emission, flue gas treatment