Substitute natural gas

About: Substitute natural gas is a research topic. Over the lifetime, 1216 publications have been published within this topic receiving 23604 citations. The topic is also known as: synthetic natural gas.

Technological method for producing coal-derived synthetic natural gas

Abstract: The invention relates to a technological method for producing coal-derived synthetic natural gas, and the method relates to the two parts of synthetic natural gas production with coal catalyzed by hydrogenation and catalyst recovery. And the two reaction processes can take place respectively in a hydrogenation reaction unit and a catalyst recovery unit. Alkali metals, alkaline earth metals, transition metals or a composite catalyst are employed to produce high quality synthetic natural gas. With the technological method of the invention, coal-derived synthetic natural gas can be obtained flexibly according to different demands. And the technological method has the advantages of easy enlargement, high carbon conversion rate, clean product and the like.

Influence of certain reaction parameters on methanation of coal gas to SNG. [4 refs]

Abstract: Methanation of coal gas to specification grade substitute natural gas (SNG) has been investigated in bench-scale tests and in a semi-commercial pilot plant. The latter plant has been operated with coal gas, which has been generated in a commercial LURGI pressure gasification plant and purified in a commercial Rectisol unit. Thus the overall scheme for SNG from coal has been demonstrated. Besides a long-term test run of 4000 hours, to evaluate a catalyst lifetime of over 16,000 hours (2 years) in a commercial plant, a number of tests have been performed to establish the influence of certain reaction parameters on methanation of CO rich synthesis gas. The influence of feed gas composition, e.g., H/sub 2//CO-ratio, CO/sub 2/-content, trace components, and catalyst poisons, have been investigated and are discussed. Catalyst activity and catalyst deactivation of two different catalysts have been determined under different operating conditions. The effect of steam in the reactor feed gas and of operating temperature on catalyst activity and catalyst deactivation have been evaluated by standard synthesis tests and by measurements of H/sub 2/-adsorption and nickel crystillite size.

Synthetic natural gas prepared from one-step process coal and system thereof

Abstract: The invention discloses a synthetic natural gas prepared from one-step process coal and a system thereof. The synthetic natural gas is prepared by the following steps: H2S and other impurities are removed from normal-temperature crude coal gas to obtain purified gas; the purified gas is preheated, subjected to removal of sulfur and other impurities, and divided into two streams; the first purified gas stream enters a thermal-insulation methanation reactor to perform methanation reaction; the reaction gas from the thermal-insulation methanation reactor is cooled by a steam superheater, and sent into an isothermal methanation reactor together with the second purified gas stream; the reaction gas from the isothermal methanation reactor is divided into two streams; the first reaction gas stream is cooled, pressurized by a recycle gas compressor, and sent into the thermal-insulation methanation reactor together with the first purified gas stream; and the second reaction gas stream is cooled, subjected to condensate separation by a condensate separator, and sent into a second absorption tower of a low-temperature methanol washer to remove CO2 and water, thereby obtaining the synthetic natural gas. The method has the advantages of simple technique, brief process, and low device operation and investment cost, and can centrally recover heat energy and coproduce high-quality steam.

Rapid Gas Hydrate Formation—Evaluation of Three Reactor Concepts and Feasibility Study

Abstract: Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.

Production of hydrogen gas using coke oven gas as raw material

Abstract: PURPOSE:To reduce reproduction cost of hydrogen and synthetic natural gas, by pretreating coke oven gas, subjecting a part of the pretreated gas to steam reforming process and CO conversion process, recovering produced hydrogen and methanating the remaining part of the gas. CONSTITUTION:Coke oven gas COG is sent to a pretreatment stage 5 via a compression stage 3 and subjected to various prescribed treatments. A part of the pretreated gas is successively transferred to a steam reforming stage 11, a CO-conversion stage 13 and a separation stage 15, in which hydrogen is separated and recovered by a pressure swing adsorption method. The produced off gas is used as a fuel for the steam reforming stage 11. Parallel to the above procedure, the remaining part of the gas transferred from the pretreatment stage 5 is sent to a methanation stage 7 and then to a purification stage 9 to obtain a synthetic natural gas SNG, etc. The operation cost for the production of hydrogen gas can be reduced by this process.