化学脱硫（干法脱硫）
Chemical desulphurization (dry desulphurization)
化学脱硫反应基本原理是：H2S与脱硫剂（氧化铁）接触，被氧化成硫或硫氧化物的一种方法，也可称为干式氧化法。干法脱硫设备的基本构成是：在特制的脱硫罐中放入填料（填料为氧化铁），气体以低流速从一端经过脱硫塔内填料层，把H2S吸附或吸收反应成硫化物或多硫化物后，余留在填料层中，净化后气体从脱硫塔另一端排出，实现脱硫处理的目的。H2S与罐内脱硫剂发生以下化学反应：
The basic principle of chemical desulfurization is that H2S is contacted with desulfurizer (ferric oxide) and oxidized to sulfur or sulfur oxide. It can also be called dry type oxidation. The basic composition of dry desulfurization equipment is put into packing in the desulfurization tank in the special (filler for iron oxide), with low gas flow rate from the end after desulfurization tower packing layer, the H2S adsorption or absorption reaction of sulfide or sulfide, remaining in the filler layer, the purified gas is discharged from the other end of the desulfurization tower. To achieve the purpose of desulfurization treatment. H2S has the following chemical reaction with the desulfurizer in the tank:
Fe2O3·H2O+3H2S→Fe2S3·H2O+3H2O
Fe2O3. H2O+3H2S - Fe2S3. H2O+3H2O
罐内脱硫剂定期晾晒再生，循环使用数次后更换。脱硫剂再生反应如下：
The desulphurizer in the tank is regularly regenerated and recycled for several times. The regenerating reaction of the desulfurizer is as follows:
2Fe2S3·H2O+3O2→2Fe2O3·H2O+6S
2Fe2S3. H2O+3O2 - 2Fe2O3. H2O+6S
脱硫剂脱硫及再生过程中，H2S与Fe2O3反应生成Fe2S3，Fe2S3与空气接触后又生成单质硫和Fe2O3。如此H2S被氧化成单质硫除去，同时脱硫剂得以再生。
In the process of desulphurization and regeneration, H2S reacts with Fe2O3 to produce Fe2S3. After Fe2S3 contact with air, it generates sulfur and Fe2O3. So the H2S is oxidized to the removal of the elemental sulfur, and the desulfurizer is regenerated.
优势：一次性投资低，运行稳定，结构简单，使用方便。
Advantages: low one-time investment, stable operation, simple structure, easy to use.
劣势：运行成本较高，脱硫剂失效快，需定期更换脱硫剂。
Disadvantages: high operating cost, fast desulphurizer, and regular replacement of desulfurizer.