With the increasing popularity of energy conservation and emission reduction policies, biogas purification is in line with the general trend of energy conservation and emission reduction. Many enterprises plan to use biogas from sewage treatment stations to replace natural gas, and then enter boilers for combustion or power generation. Then, the hydrogen sulfide removal process (desulfurization) before biogas utilization becomes a difficult choice for plant and power plant owners. At present, the commonly used processes are dry desulfurization, wet desulfurization and biological desulfurization.
1.干法脱硫
1. Dry desulfurization
干法，湿法和生物脱硫工艺的比较
Comparison of dry, wet and biological desulfurization processes
After being purified by packing layer (mainly composed of activated carbon and iron oxide), biogas flows from one end of desulfurization tower to the other. Hydrogen sulfide reacts with iron oxide in the packing layer to form iron sulfide, which can be regenerated after reaction.
Biogas purification and wet desulfurization is to send biogas into washing tower. After washing and being absorbed by alkaline solution, the washing solution will flow into rich solution tank and regeneration tank. Through chemical method, the intoxicated mouth is changed into elemental sulfur (foam foam), and the absorption liquid can be recycled.
Biological desulfurization is also a kind of wet desulfurization. Compared with the catalytic oxidation process of wet desulfurization, the difference is that Thiobacillus is used instead of chemical catalyst to directly oxidize sulfide to sulfur.
1) Dry desulfurization is usually used under the condition of low load or high demand for desulfurization effect. In this case, after wet desulfurization or biological desulfurization, dry desulfurization is usually used for further desulfurization.
2) It is suggested to formulate reasonable desulfurization effect according to the limitation of hydrogen sulfide concentration and consumption ratio of biogas and natural gas by follow-up equipment (boiler or generator). We usually recommend that the hydrogen sulfide content be controlled at 25-100ppm.
沼气提纯脱水方法：
Purification and dehydration method of biogas:
来自发酵厂的沼气包含饱和水蒸气，可以通过三种方法将其除去。
Biogas from the fermentation plant contains saturated water vapor, which can be removed in three ways.
（1）冷分离法。
(1) Cold separation method.
冷分离法是利用压力能的变化引起温度的变化并使水蒸气从气相中冷凝的方法。
The cold separation method is a method which uses the change of pressure energy to cause the change of temperature and condense the water vapor from the gas phase.
（2）溶剂吸收法。脱水溶剂是氯化钙，氯化锂和乙二醇。
(2) Solvent absorption method. The dehydration solvent is calcium chloride, lithium chloride and ethylene glycol.
(3) Solid physical water absorption method. Adsorption occurs under the action of solid surface force. According to the nature of surface force, it can be divided into chemical adsorption and physical adsorption (regeneration after dehydration).
企业二维码
2021-04-12
鲁公网安备37011202000764号号