Semi-dry Flue Gas Desulfurization (Semi-dry Flue Gas Desulfurization) is a desulfurization technology between wet and dry methods. It mainly uses lime slurry or slaked lime powder to react chemically with SO₂ in flue gas to generate calcium sulfate (CaSO₄) or calcium sulfite (CaSO₃) solid products, thereby achieving flue gas desulfurization. Common process forms include: rotary spray drying (SDA), **circulating fluidized bed method (CFB-FGD)**, etc.
★Product features of semi-dry desulfurization
Moderate desulfurization efficiency
The desulfurization efficiency is generally between 70% and 95%, which can be optimized according to the working conditions and lime usage;
It can meet medium and high-level emission requirements (SO₂ emissions ≤200mg/Nm³, and can be ≤100mg/Nm³ after optimization).
The system is relatively simple
No complex wet supporting facilities such as slurry circulation pumps, dehydration systems, and gypsum yards are required;
Small footprint and compact equipment layout.
Flue gas is unsaturated and does not produce wastewater
There is no need to cool the flue gas to the dew point, and the flue gas outlet temperature is relatively high (110-150℃), avoiding "white smoke" from the chimney;
No wastewater is produced, avoiding the water treatment problem of the wet system, and it is environmentally friendly.
Strong operating flexibility
The Ca/S ratio (calcium-sulfur ratio) can be flexibly adjusted according to the SO₂ concentration and operating load;
The start-up and shutdown speed is fast, and the ability to adapt to operating fluctuations is strong, suitable for small and medium-sized boilers or waste incinerators.
The by-product is dry powder, easy to handle
The by-product is mainly calcium sulfite/calcium sulfate powder, which can be used as a building material additive, reused or directly landfilled;
No supporting requirements such as gypsum yard and water treatment, reducing the later management cost.
★Advantages of semi-dry desulfurization
Category Advantages
Strong environmental compliance, can meet SO₂ emission standards of most industries, especially suitable for "ultra-low emission" transition or transformation projects
Low investment and operating costs, 20% to 40% less investment than wet method, simple operation and maintenance, slightly higher calcium consumption but lower overall cost
Compact equipment structure, small footprint, flexible layout, suitable for tight site or old plant transformation projects
High degree of automation, spray control, reaction tower temperature control, powder delivery, etc. can be realized by automatic joint control, suitable for unattended operation
No wastewater discharge, no water treatment system involved, no wastewater discharge, lower environmental risk
Wide range of application, can be applied to coal-fired boilers, biomass boilers, garbage incineration, chemical flue gas and other small and medium air volume flue gas treatment occasions
★Typical process Model comparison
Process type characteristics Application occasions
SDA (rotary spray drying) uses lime slurry and mixes it with flue gas through a spray dryer. Waste incineration, biomass power generation, small coal-fired power boilers
CFB (circulating fluidized bed desulfurization) Dry lime is mixed with flue gas for reaction, and the reaction products are recycled for medium-sized power plants, chemical flue gas treatment, etc.
Spray drying + bag dust removal combined with bag dust collectors to further capture reaction products to improve the efficiency of dust removal and desulfurization
★Applicable industries
Waste incineration power generation (conventional configuration desulfurization method)
Biomass boiler, waste heat boiler desulfurization system
Small and medium-sized coal-fired power plant boilers
Building materials, glass, ceramics, chemical and other industries, low- and medium-concentration SO₂ flue gas treatment
Preferred solution for areas where wet desulfurization systems cannot be installed or water resources are scarce

★Company Introduction

Yancheng Hongcheng Chaoyu Environmental Protection Co., Ltd. is a national high-tech enterprise specializing in the research and development, production, sales, installation, commissioning and service of environmental protection and energy-saving equipment such as atmospheric environment treatment, waste gas treatment and sewage treatment. It is a well-known domestic manufacturer, system integrator and general contractor of dust removal, desulfurization and denitrification, ultra-low emission, waste gas treatment and sewage treatment equipment. The various types of dust removal equipment, desulfurization and denitrification equipment, sewage treatment and other environmental protection and energy-saving equipment produced by the company are advanced in technology and reliable in quality. They are widely used in thermal power, coking, garbage power generation, chemical industry, papermaking, steel, metallurgy, carbon, glass, cement building materials and other industries. The products are sold to more than 20 provinces and cities across the country and have been widely praised by customers.

★Factory Appearance

★FAQ

Q. How high is the dust removal efficiency of bag filters?
A. The dust removal efficiency can generally reach more than 99%, and can effectively filter fine dust above 0.3 microns.

Q. Can bag filter handle high temperature gas?
A. It can handle high temperature gas up to about 250℃. It needs to use high temperature resistant filter material and control the temperature and humidity of the gas.

Q. How to extend the service life of bag filter?
A. Choose appropriate filter material, clean dust on time, avoid high temperature shock and dust blockage, and perform regular inspection and maintenance.