A method of treating natural gas to remove contaminants is described. An input natural gas is mixed with water causing formation of CO.sub.2 hydrates and CH.sub.4 hydrates. A natural gas having a reduced CO.sub.2 concentration, and a water-hydrate mixture comprising the CO.sub.2 hydrates and CH.sub.4 hydrates, is output. The water-hydrate mixture is exposed to CO.sub.2 gas forming a CO.sub.2CH.sub.4 gas mixture and a residual hydrate mixture. The CO.sub.2CH.sub.4 gas mixture is recycled to remove CH.sub.4. The residual hydrate mixture is treated to produce H.sub.2O which can be recycled for use in forming the water-hydrate mixture, and gaseous CO.sub.2 for use in use in stripping CH.sub.4 from the CH.sub.4 hydrates of the water-hydrate mixture.

To enable long-term continuous operation by preventing blocking of a reaction pipe line disposed in a multi-pipe or double-walled-pipe heat exchanger, provided is a device for producing gas hydrate including a multi-pipe or double-walled-pipe device 1 for generating gas hydrate having a reaction pipe line 2 for flowing raw material water w and raw material gas g and a coolant circulation region 3 for circulating a coolant c and thereby cooling the reaction pipe line 2, wherein a coil spring 4 extending in the longitudinal direction of the reaction pipe line 2 is provided in the reaction pipe line 2.

A method for improving gas storage capacity of a natural gas hydrate based on a crystal regulation and control principle is provided. A II structure was formed on the basis that a thermodynamic additive slightly soluble or insoluble in water was added to a hydrate generation system to compromise the hydrate generation conditions, and a crystal structure of the hydrate generated in the system was then regulated and controlled to be a I-type methane hydrate by controlling temperature and pressure. Therefore, the method for improving gas storage capacity of a natural gas hydrate is provided to creatively and fundamentally solve the problem of low gas storage capacity in the thermodynamic additive system.

A system and method for promoting generation of gas hydrates by a wall-climbing process is provided. The hydrate is induced to grow upward along a wall surface, in this process, the initially generated hydrate will form many capillary channels, a reaction liquid will move upward along these capillary channels under the action of a capillary force until the front end contacts with a gas-rich phase to form the hydrate, and so on until the reaction of all the reaction liquid is finished. In the reaction process, the hydrate needs to be induced to climb the wall upward to be generated, rather than grow into a liquid phase, which can enhance not only a gas-liquid mass transfer, but also a gas-hydrate mass transfer.

A nitrogen-carbon dioxide mixed gas jet apparatus for a horizontal well and an exploitation method is presented. The jet apparatus includes: an offshore platform, a natural gas processing unit, and a pressurizing unit, wherein a portion of the gas exploitation pipe in the hydrate layer is provided with a gas injection horizontal well; a mixed gas jet unit and a nozzle assembly are disposed in the gas injection horizontal well; the mixed gas jet unit is configured to mix nitrogen and carbon dioxide, and then inject the mixed gas into a hydrate deposition layer through the nozzle assembly, so that the mixed gas replaces methane gas in the hydrate deposition layer; the portion of the gas exploitation pipe in the hydrate layer is provided with a gas exploitation horizontal well configured to collect the methane gas and convey the methane gas to the natural gas processing unit.

A system for producing gas hydrate starting from a flow of unpurified water, comprising a multiphase multistage pump which receives at a main inlet, defining a first stage the flow of unpurified water and at a secondary inlet, defining an intermediate stage, a substance in gas state to form the hydrate. The pump is configured to increase the pressure of fluids and deliver pressurized fluids to a reactor which is configured to generate gas hydrate starting from the pressurized fluids. The reactor is configured to deliver fluid comprising gas hydrate, unreacted substance and/or water to a separator which has at least two outlets: a first (main) outlet which outputs gas hydrate and a second (secondary) outlet fluidly coupled to the secondary inlet and which outputs unreacted substance and/or water.

A device for separating and sequestrating carbon dioxide coupled with cold storage in mixed gas via hydrate method, which belongs to the technical field of application of natural gas hydrates includes a gas compression device, a refrigeration cycle device, a hydrate formation/decomposition device, a hydrate cold storage device, a water circulation device and a sensing and monitoring device; taking the separation and sequestration of biogas as an example, the refrigeration cycle device enables the cooling of biogas, decomposition of gas at all levels, hydrate, and circulating water to provide the low-temperature conditions required for hydrate formation; the hydrate cold energy storage device can fully use the latent heat of hydrate phase change to provide the required cooling capacity on the user side; the water circulation device can realize the recycling of decomposition water to ensure the continuous formation of hydrate.

A production and transportation system for natural gas hydrates includes a gas storage reservoir, a plurality of hydrate storage and transportation tanks, a refrigerator, a pressure regulating valve, a liquid storage tank, a living quarter/surrounding user, a hydrate storage reservoir, a plurality of connecting pipes, a plurality of one-way gas valves, one-way liquid valves, and optional liquid pumps. The plurality of hydrate storage and transportation tanks are connected in parallel through the connecting pipes and then connected with an output end of the gas storage reservoir through the pressure regulating valve, the liquid storage tank is connected with the optional liquid pump and then sequentially connected with the plurality of hydrate storage and transportation tanks, and the plurality of hydrate storage and transportation tanks are connected in parallel and then connected with an input end of the living quarter/surrounding user through the optional liquid pump.