Study On The Purification Technology Treating The High Sour Natural Gas Of The North-east Sichuan

Aimed to the problems in the high sour gas containing organic sulfur of the North-east Sichuan Gas Fields, this item has collected the information and data in domestic and abroad. On the basis of investigations, systematic research work has been carried out. According to the idea that adding solvent and additives into MDEA solvent could increase the desulfurization, on the pilot test unit of amine process in the laboratory, filtration and assessment of the solvent formulations had been carried out by sweetening the sour gas containing high concentrations of H₂S, CO₂ and organic sulfur. A series of experiments, such as different solvent loading, different packing height of the tower, different temperature and pressure etc, have been studied by researching the purification effect of desulfurization and decarbonization from the high sour gas. Furthermore, the regeneration and anti-foaming properties of selected solvent have been studied. The lateral-line test on the laboratory studies has been carried out, and further research of the properties has been also studied. Laboratory tests showed that the chosen solvent has a good removal capacity to the organic sulfur of the sour natural gas. In absorbing the pressure of 6.0MPa and the component of the raw gas, regardless of the acid gas loading which was 0.53mol acid gas / mol or 0.59mol acid gas / mol amine, the organic sulfur content of the sweetening gas was under 100mg/m³. When the acid gas loading was 0.59mol acid gas / mol Amine, H₂S content of the sweetening gas was under 20mg/m³, CO₂ content of the sweetening gas was under 3 percent, and the organic sulfur removal rate was beyond 85 percent. The sweetening gas measured up the second category of GB17820-1999. And when the acid gas loading was 0.53mol acid gas / mol Amine, H₂S content of the purification gas was under 6mg/m³, CO₂ content of the sweetening gas was under 3 percent, and the organic sulfur removal rate was beyond 89 percent. The sweetening gas measured up the first category of GB17820-1999. The lateral-line Tests showed the absorption pressure of 3.3MPa and raw gas conditions, the chosen solvent has also good removal effect to H₂S and the organic sulfur of the high sour natural gas. When the gas-liquid ratio was 440, organic sulfur removal rate was beyond 70 percent, the purification gas measured up the second category of GB17820-1999. When the gas-liquid ratio was 300, desulfurization rate was beyond 80 percent, the purification gas measured up the first category of GB17820-1999. This solvent has good regeneration property, low foaming tendency in the sweetening process and anti-foaming ability. The report also recommended the process operation conditions when applying the chosen solvent to the purification devices in future.