Tail gas treatment skid
Natural gas tail gas treatment skid is mainly used to deal with the tail gas of sulfur recovery device, as well as the waste gas of liquid sulfur pool and TEG waste gas of dehydration device of sulfur recovery device.
The design and processing capacity of the skid are matched with sulfur recovery device and dehydration device.
Natural gas tail gas treatment skid can be divided into four categories.
1. Reduction and absorption process
The principle of reduction and absorption process is that the tail gas is hydrogenated, the sulfur-containing components in the tail gas are reduced to H2S, the generated H2S is selectively absorbed by amine method, and finally the regeneration or gas is extracted to enter Claus unit for circulating reaction. Hydrogenation process has high investment and high operation cost, but it is widely used in countries and regions with high environmental protection requirements because it can achieve a fairly high sulfur yield, such as more than 99.8%.
2. Oxidation absorption process
Oxidation absorption method is a method that first oxidizes sulfide in tail gas to SO2, then absorbs SO2 with solution (or solvent), and finally recovers it in the form of sulfate, sulfide and SO2.
There are many methods belonging to this type, most of which are used for flue gas desulfurization or treatment of tail gas from smelters and sulfuric acid plants, and Wellman Lord method is used for Claus tail gas treatment.
3. Low temperature Claus process
Low temperature Claus technology is characterized by Claus reaction below sulfur dew point, so it is also called sub dew point sulfur recovery process. Claus reaction is a strong exothermic reaction process. Therefore, low temperature is conducive to the shift of equilibrium to the direction of sulfur generation, which can improve the sulfur recovery. According to the relationship between Claus reaction and unit, low temperature Claus process can be divided into independent low temperature Claus process and combined low temperature Claus process.
4. Liquid phase direct oxidation process
Liquid phase direct oxidation process is a kind of process technology that directly oxidizes H2S to elemental sulfur. The principle of this process is to absorb the H2S in the tail gas with desulfurization solution, and then oxidize it to generate elemental sulfur.
1, SO2 ≤ 400mg/Nm3(dry basis,3vol% O2)
2 ,Annual production time 8000 hours
3 ,Operating flexibility 50%~120%