Study On The Desulfurizing And Dehydration Technology Of Compress Natural Gas For Vehicles In Northeast China

H₂S is a harmful impurity in the natural gas. It can not only cause the pipeline and equipment to be corroded so as to influence the follow up processing(as leading to catalyst poisoning)but also seriously threaten the personal safety, belonging to one of the environmental pollution sources which must be controlled. The key that whether the compressed natural gas (CNG) used as vehicle fuel could meet the requirements of a vehicle in use is dehydration on the promise that sulfur content and heating value of the natural gas accord with the set indexes of commercial natural gas. If the water content in CNG is not up to the standard, the CNG filling station and CNG vehicle are disable to run, even extremely dangerous accidents will be caused. Thus, how dehydration way will be adopted to enable the water content to be up to the standard is extremely important. Owing to the reasons that the territory of China is vast, the oil and gas distribution is wide, the count ry2wide pipe network is not formed and the processing ways are different in different oil and gas fields, etc. the water content in the commercial natural gas supplied to fuel market is different with the difference of regions and the variation of seasons. For this reason, in designing a CNG filling station, the dehydration system for CNG must be correctly and rationally designed in the light of the concrete conditions. The desulfurizing technology is mostly composed of the dry process and wet process, which is mostly used for the treatment of high or low H2S content of the natural gas. The necessity for dehydration of CNG, the determination of dehydration degree, the directions of the low, medium and high pressure dehydration methods, the technological process, the characteristics of the main equipments and the selection of optimum dehydration plan ,etc. are introduced in this paper. Finally, it is pointed out that the key to success or failure for CNG dehydration system depends on the design, because only a correct design can guarantee the CNG dehydration system to run safely and normally, and so do the CNG filling station and NG vehicle. Meanwhile, this paper made a comparison of the methods of desulfurizing and dehydration in the CNG filling station which using the Honggang gas field in Daqing in Northeast China, and then made an economical and effective scheme.