Steam Reforming Hydrogen Plant CO2 Separation
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Solution Overview
Problem
Current steam reforming processes for producing pure hydrogen face challenges in reducing carbon dioxide emissions, particularly due to high indirect and direct CO2 emissions, and inefficient carbon dioxide separation from synthesis gas and flue gas streams, which are energy-intensive and costly.
Innovation Solution
A process that separates carbon dioxide from both the cooled converted synthesis gas stream and the reformer furnace flue gas using suitable carbon dioxide separation processes, incorporating amine scrubbing and membrane separation methods, with integrated heat recovery and steam utilization to enhance energy efficiency and reduce emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If carbon dioxide is separated from synthesis gas and flue gas using conventional methods, then carbon dioxide removal is achieved, but energy consumption increases and operating costs rise
Solution Approach 1:
The patent divides CO2 separation into two distinct segments: (1) separation from synthesis gas stream, and (2) separation from flue gas stream. This segmentation allows each separation unit to be optimized independently for its specific gas composition and operating conditions, reducing overall energy consumption compared to a single centralized separation system.
Solution Approach 2:
The patent implements preliminary CO2 removal from the synthesis gas stream before the gas is combusted in the reformer furnace. This preliminary action reduces the carbon load entering the furnace, thereby decreasing the amount of CO2 that needs to be separated from the flue gas, which is energetically more favorable than separating CO2 from the larger volume of flue gas after combustion.
2Object-generated harmful factors
If carbon dioxide separation processes are implemented, then carbon dioxide emissions are reduced, but the complexity of the process increases
Solution Approach 1:
The patent extracts CO2 from two different process streams (synthesis gas and flue gas) using separate separation units. This extraction approach allows the use of different separation technologies optimized for each stream's characteristics, managing complexity through functional decomposition rather than attempting a single complex separation system.
Solution Approach 2:
The patent recovers CO2 from both the synthesis gas stream and flue gas stream, treating CO2 as a recoverable component rather than waste. This dual-recovery strategy is implemented through modular separation units that can be independently operated and maintained, managing system complexity through standardization and modularity.
3Object-generated harmful factors
If conventional carbon dioxide separation methods are used, then some carbon dioxide is removed, but the separation rate is insufficient and energy-intensive
Solution Approach 1:
By segmenting CO2 separation into two distinct process stages (synthesis gas stream treatment and flue gas stream treatment), the patent achieves higher overall separation rates. Each segment targets a specific portion of the total CO2 emissions, allowing optimized separation conditions for each stream and improving the efficiency of CO2 removal at each stage.
Solution Approach 2:
The preliminary removal of CO2 from the synthesis gas stream before combustion reduces the total CO2 load that must be handled downstream. This preliminary action increases the effective separation rate by addressing CO2 removal at an earlier, more favorable point in the process where CO2 concentration is higher and separation is more efficient.
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 achieves higher carbon dioxide separation rates with lower energy consumption and operating media usage, improving energy efficiency and reducing overall carbon dioxide emissions while maintaining hydrogen production capacity.
Implementation Method 1
separates carbon dioxide from both the cooled converted synthesis gas stream and the reformer furnace flue gas using suitable carbon dioxide separation processes, incorporating amine scrubbing
Implementation Method 2
incorporating amine scrubbing and membrane separation methods
Implementation Method 3
with integrated heat recovery and steam utilization to enhance energy efficiency
Implementation Method 4
Hydrocarbons can be catalytically reacted with steam to give synthesis gas, i.e. mixtures of hydrogen (H2) and carbon monoxide (CO). As is explained in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition, 1998 Electronic Release, under 'Gas Production', what is called steam reforming is the most commonly employed method for the production of synthesis gas
Implementation Method 5
If the synthesis gas production is primarily directed to the generation of pure hydrogen, the hydrogen content in the synthesis gas generated is increased by the application of CO conversion, also referred to as the water-gas shift reaction (WGS) or CO shift reaction, according to the following conversion equation: CO+H2O=CO2+H2
Data Source
AI summary
A process and a plant for producing pure hydrogen by steam reforming of a feed gas containing hydrocarbons. preferably natural gas or naphtha. with reduced carbon dioxide emissions are proposed. The reduction in carbon dioxide emissions is achieved in accordance with the invention in that carbon dioxide is separated both out of the converted cooled synthesis gas and out of the flue gas from the reformer furnace by means of suit-able measures.