Membrane separation and hydrate combined gas desulfuration and deacidifying device and method

Abstract

The invention belongs to the field of oil and gas storage and transportation technology engineering, and particularly relates to a membrane separation and hydrate combined gas desulfuration and deacidifying device and method. According to the device, hydrate reactors are adopted for processing feed gas under appropriate pressure before the feed gas enters a membrane assembly, and nearly all hydrogen sulfide and most of carbon dioxide can be removed; meanwhile, the dust removal function is achieved, the load of the follow-up membrane assembly is reduced greatly, and the replacement frequency of membranes is reduced. By the adoption of the method that acid gas is fixed in a hydrate mode and unreacted gas is used as net gas to be circulated, loss of light hydrocarbon can be reduced, and gas can be directly used as net gas to be transported out through a gas outlet of the second hydrate reactor after being up to the standard. The hydrogen sulfide and the carbon dioxide which exist in a solid hydrate form can be conveniently transported to a centralized processing device to be processed, and acid gas processing independence is enhanced.

Description

technical field [0001] The invention belongs to the technical engineering field of oil and gas storage and transportation, and particularly refers to a method for desulfurization and deacidification of natural gas by combining membrane separation and hydrate method, which is applied to the purification and separation of natural gas in onshore and offshore oil and gas fields, especially Natural gas processing in remote areas and some small gas fields. Can effectively remove H from natural gas 2 S and CO 2 Wait for the acid gas to make it meet the pipeline transportation standard. Background technique [0002] Natural gas extracted from oil and gas fields is composed of hydrocarbons and various impurity gases, the main component of which is methane, and also contains H 2 S, organic sulfur, CO 2 The existence of these acidic substances will not only corrode pipelines and equipment, but also cause serious pollution to the environment. Therefore, the country has strict regula...

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Problems solved by technology

Chemical absorption was earlier used to remove H from natural gas 2 S and CO 2 The literature (Wang Lanzhi, Li Guiming, Yang Hongjian, etc. Research Progress in Natural Gas Purification Technology [J]. Henan Chemical Industry, 2006, 23:11-13.) introduced in detail the removal of sulfur in natural gas by various absorbents The hydrogen method, but this method generally has relatively large equipment, high investment costs, and problems such as regeneration and environmental pollution; the membrane absorption method has more advantages than the chemical absorption method, and the patent "Membrane Absorption Natural Gas Desulfurization Method" (200510095472.0, published (Announcement) No. CN 1785480A) pointed out that the investment cost of membrane absorption method is about 30%-40% less than that of pure chemical absorption, and it can effectively remove H in natural gas. 2 S to make it meet the national standard, but this method is essentially developed on the basis of the membrane separation method. It is a method that combines membrane separation and chemical absorption. There are still relatively high operating costs and the existence of Due to problems such as regeneration pollution, the simple membrane separation method cannot make H 2 S and CO 2 It is effectively removed, but the efficiency is not high, but the membrane separation method is easy to operate, low in investment, and has great development prospects; literature (Yu Haojie. Industrial experiments on unconventional purification methods for natural gas in Changqing Gas Field[J]. Inner Mongolia Petrochemical, 1997, 23 (SI): 54-64.) specifically elaborated on this aspect. The use of hydrates for desulfurization is a new method, and the patent "method for removing hydrogen sulfide from natural gas" (201010274051.5, published ( Announcement) No. CN 101955828A) proposed a specific method of using hydrate method for desulfurization. However, as the partial pressure of hydrogen sulfide gradually decreases during the hydrate reaction process, the formation becomes more and more difficult, and it is difficult to make hydrogen sulfide in natural gas The content reaches the national standard. In addition, the literature (Xi Wang, Shen Jie. Research progress in natural gas desulfurization technology [J]. Gas and Thermal Power, 2010,30(11):31-33.) also pointed out that microbial desulfurization, high gravity oxidation Reduction desulfurization and other methods, but there is still a long way to go for industrial application of these technologies

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