Steam Reforming Plant Dual-Mode Recycle Compressor
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Solution Overview
Problem
There is a need to improve the production of hydrogen-rich synthesis gas in steam reforming reactors without significant increases in capital costs, as existing methods often require additional equipment or energy to achieve higher hydrogen/carbon monoxide ratios.
Innovation Solution
The steam reforming plant operates in two modes: one where carbon dioxide is recycled using a compressor to the hydrocarbon feed, and another where residual gas from pressure-swing adsorption is added to the hydrogen-rich stream upstream of the pressure-swing adsorption plant, allowing for increased hydrogen yield without additional capital expenditures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If carbon dioxide is recycled to the hydrocarbon feed to control hydrogen/carbon monoxide ratio, then the hydrogen/carbon monoxide ratio can be adjusted, but the hydrogen yield is limited and plant size must be increased to achieve higher hydrogen production
Solution Approach 1:
The system dynamically switches between two operational modes: Mode 1 recycles carbon dioxide to the reformer to control the hydrogen/carbon monoxide ratio, while Mode 2 recycles residual gas to the hydrogen-rich fraction to maximize hydrogen yield. This dynamic switching allows the plant to adapt to varying product requirements without physical expansion.
Solution Approach 2:
The invention changes the operational parameters by switching between different recycle stream configurations. In Mode 1, the recycle stream is carbon dioxide from the separation unit to the reformer feed. In Mode 2, the recycle stream is residual gas from pressure-swing adsorption to the hydrogen-rich fraction. This parameter change enables flexible adjustment of hydrogen production levels.
2Productivity
If plant size is increased to achieve higher hydrogen production, then hydrogen yield increases, but capital costs increase significantly
Solution Approach 1:
The existing recycle compressor is made multi-functional by enabling it to serve two different purposes: recycling carbon dioxide in Mode 1 for ratio control, and recycling residual gas in Mode 2 for hydrogen yield enhancement. This eliminates the need for additional compression equipment and avoids capital expenditure for plant expansion.
Solution Approach 2:
The system uses its own internal residual gas stream to enhance hydrogen production without requiring external resources or additional equipment. The residual gas from pressure-swing adsorption is recycled back to the hydrogen-rich fraction, allowing the plant to self-enhance its hydrogen yield using already-present materials.
3Productivity
If residual gas is recycled to hydrogen-rich fraction, then hydrogen yield increases by 5-10%, but the operational mode must be changed from carbon dioxide recycling
Solution Approach 1:
The control system dynamically switches between operational modes based on production requirements. The ability to quickly transition between Mode 1 (carbon dioxide recycling) and Mode 2 (residual gas recycling) minimizes operational complexity while maximizing flexibility. The system adapts its configuration rather than requiring complex manual reconfiguration.
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 increases the hydrogen/carbon monoxide ratio up to 4.8, enhancing hydrogen yield by 5-10% without enlarging the plant, allowing for either increased hydrogen production or reduced plant load, and is adaptable to meet varying product requirements.
Implementation Method 1
a hydrocarbon feed such as natural gas, liquid gas or naphtha is endothermically reacted with steam in a catalytic tubular reactor
Implementation Method 2
reacted with steam in a catalytic tubular reactor
Implementation Method 3
These impurities are separated in a pressure-swing adsorption plant
Data Source
AI summary
A method for operating a steam reforming plant wherein a hydrocarbon-rich feed is reacted with steam to form synthesis gas. The plant includes a steam reforming reactor and processing units to obtain a hydrogen-rich fraction after separation of carbon dioxide and carbon monoxide. The plant also includes a pressure-swing adsorption plant to separate the hydrogen-rich fraction into product and residual gas. A recycle compressor is included and allows the plant to operate is two different modes. In the first mode, carbon dioxide separated from the synthesis gas is compressed and added to the hydrocarbon-rich feed. In the second mode, the recycle compressor is used to recycle residual gas from the pressure-swing adsorption plant to the hydrogen-rich fraction upstream of the pressure-swing adsorption plant.