Heat Integration in Acid Gas Removal Solvent Regeneration
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Solution Overview
Problem
Existing acid gas removal processes, such as the Selexol® process, face inefficiencies due to low feed temperatures in the hot solvent regeneration loop and energy losses in heat exchangers, leading to increased energy consumption and reduced process efficiency.
Innovation Solution
Utilizing overhead waste process heat to increase the feed temperature of the hot solvent regeneration loop by separating and heating slip streams from rich solvent streams, which are then combined with heated rich solvent streams to enhance the temperature and efficiency of the regeneration process, thereby reducing energy losses and improving heat integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional heat exchange processes are used in the hot solvent regeneration loop, then the process can operate with standard equipment, but energy losses increase and process efficiency decreases
Solution Approach 1:
The patent combines multiple heat exchange functions into an integrated system where the bridge heat exchanger merges the hot solvent stream with the slip stream, and the stripper gas heat exchanger merges heated slip stream with rich solvent stream. This merging of heat exchange pathways eliminates energy losses by ensuring all available heat is utilized in the regeneration process.
Solution Approach 2:
The patent converts the previously wasted overhead process heat into a beneficial resource by routing it through the bridge heat exchanger and stripper gas heat exchanger to preheat solvent streams. The waste heat that would have been lost is now utilized to increase feed temperature and reduce reboiler duty, transforming an energy loss into a process advantage.
2Use of energy by moving object
If the feed temperature to the hot solvent regeneration loop is increased, then energy consumption is reduced, but additional heating equipment and process complexity are required
Solution Approach 1:
The bridge heat exchanger and stripper gas heat exchanger perform multiple functions: they transfer heat from waste streams to solvent streams, preheat feed to the regeneration loop, and utilize overhead waste process heat. This multi-functionality allows the system to achieve higher feed temperatures and reduced energy consumption without requiring separate dedicated heating equipment for each function.
Solution Approach 2:
The system uses its own overhead waste process heat to preheat the solvent streams entering the regeneration loop. The heat exchangers are positioned within the process itself, allowing the process to self-heat using internally generated waste heat, thereby reducing external energy requirements and minimizing the need for additional heating equipment.
3Loss of energy
If overhead waste process heat is utilized to increase feed temperature, then energy savings are achieved, but additional heat exchangers and process steps are required
Solution Approach 1:
The bridge heat exchanger and stripper gas heat exchanger serve as intermediaries that transfer heat from the waste process heat streams to the solvent streams requiring heating. These intermediary heat exchangers enable the utilization of waste heat without requiring direct mixing or complex heat integration, achieving energy savings while maintaining process simplicity through standardized heat exchange equipment.
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 temperature of the hot solvent regeneration loop, enhances the performance of downstream units, reduces the reboiler duty, and achieves energy savings of up to 20% by optimizing heat recovery and reducing stripping gas requirements.
Implementation Method 1
at least one absorber including an absorbent material that absorbs acid gas. Acid gas can be removed from the feed gas by absorption to produce a first rich solvent stream including solvent and acid gas
Implementation Method 2
At least one slip stream can be separated from the first rich solvent stream, and the at least one slip stream can be heated by heat exchange to produce at least one heated slip stream
Implementation Method 3
At least a portion of the first rich solvent stream can be passed to a bridge heat exchanger to produce a heated rich solvent stream
Data Source
AI summary
Systems and processes utilize one or more methods of providing overhead waste process heat to increase the feed temperature of the hot solvent stripping regeneration loop in an acid gas removal process. A heated rich solvent stream can be the primary feed for the hot solvent stripping regeneration loop, and one or more slip streams can be heated and then combined with the heated rich solvent stream to form a combined rich solvent stream prior to further processing in downstream units to remove acid gas from the solvent. A first slip stream can be heated in a stripper gas heat exchanger by heat exchange with a stripped gas stream. A second slip stream can be heated in a regenerator exchanger by heat exchange with an acid gas stream. A third slip stream can be heated in a recycle gas exchanger by heat exchange with a compressed recycle gas stream.