Oxygen-Blown Gasifier Eliminates Methane Recycle Loops
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Solution Overview
Problem
Current methane production methods via catalytic gasification of carbonaceous feedstocks require complex gas recycle loops, increasing engineering complexity and costs due to the need for recycling carbon monoxide and hydrogen.
Innovation Solution
A process that eliminates gas recycle loops by using an oxygen-blown gasifier to generate a steam-rich gas stream, which is then used in a catalytic gasifier with a gasification catalyst, followed by heat recovery and methanation to produce a methane-enriched stream, reducing the reliance on recycling carbon monoxide and hydrogen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If gas recycle loops are used to maintain thermal neutrality in methane production, then the reaction can be kept thermally neutral, but the engineering complexity and overall cost are greatly increased
Solution Approach 1:
The patent extracts and eliminates the gas recycle loop from the conventional gasification process. By using an oxygen-blown gasifier instead of an air-blown gasifier, the process generates a syngas stream with sufficient heating value without requiring recycling of CO and H2, thereby removing the complex recycle infrastructure while maintaining thermal neutrality through the exothermic combustion reactions in the oxygen-blown gasifier
Solution Approach 2:
The patent applies strong oxidation by using pure oxygen instead of air in the gasifier. This accelerated oxidation enables complete combustion of the carbonaceous feedstock, generating high-temperature syngas with sufficient heating value to sustain the reforming reactions without recycle, thereby simplifying the process while maintaining energy balance
2Loss of energy
If gas recycle loops are implemented, then thermal neutrality can be maintained, but additional heating elements and pressurization elements are required
Solution Approach 1:
The patent removes the need for additional heating elements and pressurization elements by eliminating the recycle loop. The oxygen-blown gasifier generates syngas at high temperature and pressure directly, providing the necessary thermal and mechanical energy without requiring separate heating and pressurization equipment for recycle streams
Solution Approach 2:
The patent combines multiple functions into the oxygen-blown gasifier: it performs combustion, generates syngas, provides thermal heating, and maintains system pressure. This consolidation eliminates the need for separate heating elements and pressurization elements that would be required in a conventional recycle-based process
3Quantity of substance
If methane is separated from recycle gases by cryogenic distillation, then methane can be recovered, but the engineering complexity and overall cost of producing methane is greatly increased
Solution Approach 1:
The patent extracts and eliminates the cryogenic distillation unit from the process. By using an oxygen-blown gasifier, the syngas stream contains sufficient methane and has appropriate composition without requiring complex separation and recycling infrastructure, thereby simplifying the overall process while maintaining effective methane recovery
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the production process, reduces costs, and achieves high thermal efficiency by utilizing the oxygen-blown gasifier as both a syngas generator and superheater, eliminating the need for separate recycling and superheating steps.
Implementation Method 1
at least partially combusting the first carbonaceous feedstock with the oxygen-rich gas stream in the oxygen-blown gasifier
Implementation Method 2
reacting the second carbonaceous feedstock and the first gas stream in the catalytic gasifier in the presence of the gasification catalyst
Implementation Method 3
recovering a portion of the heat energy from the second gas stream, wherein at least a portion of the recovered heat energy is utilized to generate a first steam recycle stream
Data Source
AI summary
The present invention relates to processes and continuous processes for preparing gaseous products, and in particular, methane via the catalytic gasification of carbonaceous feedstocks in the presence of steam. In one aspect of the invention, the processes comprise at least partially combusting a first carbonaceous feedstock with an oxygen-rich gas stream, a recycle steam stream, and an aqueous make-up stream in an oxygen-blown gasifier, under suitable temperature and pressure, to generate a first gas stream comprising hydrogen, carbon monoxide and superheated steam; and reacting a second carbonaceous feedstock and the first gas stream in a catalytic gasifier in the presence of a gasification catalyst under suitable temperature and pressure to form a second gas stream comprising a plurality of gaseous products comprising methane, carbon dioxide, hydrogen, carbon monoxide and hydrogen sulfide. The processes can comprise using at least one catalytic methanator to convert carbon monoxide and hydrogen in the gaseous products to methane and in certain embodiments do not recycle carbon monoxide or hydrogen to the gasifier. Heat energy recovered from the catalytic gasification can be used to generate the recycle steam stream.