Process to Produce a Methane Rich Gas Mixture from Gasification Derived Sulphur Containing Synthesis Gases

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention describes a process for converting raw synthesis gases produced from the gasification of coal or biomass—which contain problematic sulfur and nitrogen compounds—into a clean, methane-rich gas. The method involves a series of catalytic and separation steps, including fluidized bed reactors for methanation and hydrodesulphurization, sulfur removal, carbon dioxide removal, and hydrogen separation. The end product is a substitute natural gas (SNG) suitable for injection into natural gas grids or use in high-temperature fuel cells.

Use CasesContent extracted from patent full text and abstract with AI.

• Producing substitute natural gas (SNG) from coal or biomass for energy supply
• Feeding methane-rich gas directly into existing natural gas pipelines
• Providing clean fuel for high-temperature fuel cells
• Supplying synthetic natural gas for power generation, heating, or transportation
• Processing synthesis gas in chemical industries for further conversion

BenefitsContent extracted from patent full text and abstract with AI.

• Enables the use of low-value, sulfur-rich materials like coal or biomass to produce clean methane fuel
• Reduces the number of processing units and temperature variations compared to traditional methods, leading to process efficiency
• Removes harmful sulfur and nitrogen compounds, improving catalyst life and product gas purity
• Produces a product compatible with existing natural gas infrastructure
• Allows for recycling of hydrogen within the process to maximize efficiency and reduce waste
• Potential for internal regeneration of catalysts, reducing maintenance and operational costs

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Patent Abstract

The present invention discloses a method for converting a raw gas into a methane-rich and/or hydrogen-rich gas, comprising the steps of : a) providing the raw gas stemming from a coal and/or biomass gasification process, thereby the raw gas comprising beside a methane and hydrogen content carbon-monoxide, carbon-dioxide, alkanes, alkenes, alkynes, tar, especially benzole and naphthalene, COS, hydrogen sulfide and organic sulfur compounds, especially thiophenes; thereby the ratio of hydrogen to carbon monoxide ranges form 0.3 to 4; b) bringing this raw gas into contact with a catalyst arranged as a fluidized bed reactor at temperatures above 200°C and at pressures equal or larger than 1 bar in order to convert the raw gas into a first product gas, thereby simultaneously convert organic sulfur components into hydrogen sulfide, reform tars, generate water/gas shift reaction and generate methane from the hydrogen/carbonmonoxide content; c) bringing the first product gas into a sulfur absorption process to generate a second product gas, thereby reducing the content of hydrogen sulfur and COS from 100 to 1000 ppm down to 1000 ppb or less; d) optionally bringing the second product gas into a carbon dioxide removal process to generate a third product gas at least almost free of carbon dioxide; e) bringing the third product gas into a 2nd methanation process to generate a forth product gas having a methane content above 5 vol%; f) ) optionally bringing the fourth product gas into a carbon dioxide removal process to generate a fifth product gas at least almost free of carbon dioxide g) bringing the fifth product gas into an hydrogen separation process in order to separate a hydrogen rich gas from a remaining methane-rich gas, called substitute natural gas.