Flue Gas Treatment Upgrade | Ultra-Low Emission Retrofit of Lime Kilns Achieves Stable Compliance

Recently, the kiln-tail flue gas environmental purification project for Lines No. 1, No. 2, and No. 3 at Shaanxi Huateng Nanotechnology Co., Ltd., undertaken on a general contracting basis by Jiehua Holdings, was fully completed and successfully put into operation, achieving ultra-low emission targets for dust, SO₂, NOx, and ammonia slip. Following the retrofit, all three production lines now meet the specified indicators set out in the national ecological and environmental standard "Technical Guidelines for Performance-Based Classification of Air Pollution Prevention and Control in Key Industries and Emergency Emission Reduction Measures During Heavy Pollution Weather — Cement Industry (Draft for Comments)", giving the company greater confidence in responding to future heavy pollution weather emergency management requirements.

Kiln-tail exhaust from lime production lines is characterized by high temperatures and a low baseline SO₂ concentration. Taking into account the actual operating conditions at the Huateng Nanotechnology project, our company designed a tailored treatment route combining "high-activity calcium-based dry desulfurization + bag filter dust removal + low-temperature, low-dust SCR denitrification."

First, through highly efficient, coordinated removal of SO₂ and dust in the upstream process stages, the SCR denitrification reactor is able to operate stably at a low temperature of 180°C. Under low-dust conditions, the catalyst requires only an acoustic soot-blowing system, substantially cutting the energy consumption of soot blowing compared with conventional high-dust or medium-dust SCR routes — truly achieving "low-energy-consumption denitrification."

Second, the project was forward-looking in incorporating a catalyst heating and regeneration system, which effectively guards against the risk of ammonium sulfate poisoning caused by process fluctuations, significantly extends catalyst service life, and reduces the customer's operation and maintenance costs over the full equipment lifecycle.

The successful implementation of this project achieves in-depth pollutant treatment while ensuring reliable equipment operation, effectively controlling both energy consumption and O&M costs — delivering environmental and production benefits in tandem. It also offers a highly valuable engineering reference model for flue gas denitrification retrofits on cement clinker lines.