Methanol Synthesis Off-Gas Recovery for Hydrogen Co-Production
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Solution Overview
Problem
Current methods for co-producing hydrogen and methanol are inefficient in terms of energy and cost, with significant hydrogen purge gas containing valuable carbon oxides being wasted, and existing solutions require high capital costs or oxygen supplies.
Innovation Solution
A method involving a hydrocarbon processing reforming or gasification process generating a syngas stream, with a portion introduced to a once-through methanol synthesis reactor, followed by separation into crude methanol and off-gas streams, and further processing to produce pure hydrogen, utilizing a single waste heat recovery/cooling system to minimize capital expenditure and maximize energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a conventional co-production facility is used, then both hydrogen and methanol can be produced, but significant hydrogen purge gas containing valuable carbon oxides is wasted and capital costs are high
Solution Approach 1:
The invention extracts and utilizes the hydrogen-containing purge gas from the methanol synthesis loop by introducing it back into the methanol reactor. This extraction of the problematic purge stream and its constructive reuse eliminates waste while simplifying the overall process by avoiding complex separation and recycling systems.
Solution Approach 2:
The invention merges the hydrogen production and methanol production processes into a single integrated system where the methanol reactor serves dual purposes: producing methanol while also consuming the hydrogen-rich purge gas. This consolidation eliminates the need for separate purge handling systems and reduces capital costs.
2Productivity
If existing co-production methods are implemented, then hydrogen and methanol can be produced together, but additional oxygen supplies and high capital costs are required
Solution Approach 1:
The methanol reactor is designed to perform multiple functions simultaneously: it produces methanol from synthesis gas while also consuming the hydrogen-rich purge gas that would otherwise be wasted. This multi-functionality increases productivity without requiring additional dedicated equipment or oxygen supply systems.
Solution Approach 2:
The system uses its own internal purge gas stream as a feedstock for the methanol reactor, creating a self-sufficient process that eliminates the need for external oxygen supplies or additional fuel inputs. The purge gas that would normally be discarded becomes a valuable resource within the system.
3Loss of energy
If hydrogen is produced at the same location where it is consumed, then transportation costs are eliminated, but methanol transportation emissions are avoided only if co-production is implemented
Solution Approach 1:
The invention combines hydrogen production and methanol production into a single facility, allowing both products to be generated on-site where they are needed. This eliminates the need for separate methanol production, storage, and transportation infrastructure, thereby reducing both emissions and facility complexity.
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 enables cost-effective and energy-efficient co-production of hydrogen and methanol by reducing waste hydrogen purge gas and eliminating the need for additional oxygen supplies, while simplifying the process and reducing capital costs through minimal equipment additions.
Implementation Method 1
A method for the co-production of hydrogen and crude methanol from synthesis gas obtained by reforming light hydrocarbons
Implementation Method 2
a hydrocarbon processing reforming or gasification process generating a syngas stream
Implementation Method 3
The synthesis gas may be produced in a steam reformer, an autothermal reformer, or a partial oxidation reformer containing hydrogen, carbon monoxide, and carbon dioxide
Implementation Method 4
introducing at least a portion of the stream from methanol reactor to a separation device separating this stream into a crude methanol stream and methanol synthesis off gas stream
Data Source
AI summary
A method for the co-production of hydrogen and crude methanol, including; a hydrocarbon processing reforming or gasification process generating a syngas stream comprising hydrogen, carbon monoxide and carbon dioxide; introducing at least a portion of the syngas stream to a once-through methanol synthesis reactor: introducing at least a portion of the stream from methanol reactor to a separation device separating this stream into a crude methanol stream and methanol synthesis off gas stream; introducing at least a portion of the methanol synthesis off gas to a hydrogen separation device, thereby producing a pure hydrogen stream.