Sorption Regeneration for Equilibrium-Restricted Reaction Productivity
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Solution Overview
Problem
Equilibrium-restricted reactions, such as ammonia and methanol production, face limitations in single pass conversion and require large recycles due to incomplete separation of reactants and products, leading to reduced efficiency and increased energy consumption.
Innovation Solution
A process involving a sorption step where the product mixture is contacted with a selective sorbent, followed by regeneration using reactor off-gases, enhances single pass conversion and reduces energy costs by allowing less stringent separation conditions, such as operating a condenser at 30°C instead of −5°C, without additional heating or cooling steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large recycle stream is used to increase ammonia yield, then the overall conversion is improved, but the reactor productivity and energy efficiency deteriorate due to incomplete separation and high energy consumption
Solution Approach 1:
The invention extracts the product (ammonia) from the recycle stream using a selective membrane separator before it re-enters the reactor. This removal of product from the recycle loop allows for higher single-pass conversion while reducing the overall recycle ratio, thereby improving energy efficiency while maintaining high ammonia yield.
Solution Approach 2:
The invention changes the separation parameter from conventional condensation (requiring low temperatures and high pressures) to membrane-based selective permeation. This allows separation to occur at milder conditions, reducing energy consumption while achieving the same or better separation efficiency.
2Quantity of substance
If conventional separation methods are used, then product recovery is achieved, but the separation conditions become more stringent and energy consumption increases
Solution Approach 1:
The invention replaces the mechanical/thermal separation system (condensers, heat exchangers requiring temperature and pressure changes) with a membrane-based separation system that utilizes selective permeation. This substitution eliminates the need for stringent thermal conditions while achieving effective product recovery.
Solution Approach 2:
The invention changes the separation mechanism from thermodynamic phase equilibrium (condensation) to kinetic selective permeation through membranes. This parameter change allows separation at ambient or near-ambient conditions, dramatically reducing energy consumption while maintaining high product recovery.
3Quantity of substance
If the recycle contains significant amounts of product, then the separation is incomplete, but the reactor conversion is reduced due to equilibrium limitations
Solution Approach 1:
The invention extracts ammonia selectively from the recycle stream using membrane separation, ensuring more complete removal of product before recycling. This reduces the product concentration in the recycle stream, shifting the equilibrium forward and increasing reactor conversion while maintaining high overall productivity.
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 process increases the productivity of existing reactors, allowing for their retrofitting or the reduction in size of new reactors while maintaining productivity, and reduces energy consumption by optimizing heat management and separation efficiency.
Implementation Method 1
a sorption step, wherein the reactant stream originating from step (d) and/or an intermediate reaction mixture is contacted with a sorbent selective for one or more of the products of the equilibrium reaction
Implementation Method 2
regenerating the loaded sorbent obtained in step (e) by flushing the loaded sorbent with the reactor outlet mixture originating from step (b)
Implementation Method 3
regenerating the loaded sorbent obtained in step (e) by flushing the loaded sorbent with the reactor outlet mixture originating from step (b), to obtain regenerated sorbent and an effluent comprising desorbed product
Data Source
AI summary
A process for increasing the productivity of equilibrium-restricted reactions and for increasing the productivity of a target compound includes the steps of (a) providing a reaction mixture comprising reactants; (b) subjecting the reaction mixture to the equilibrium reaction in a reactor or sequence of reactors, to obtain a reactor outlet mixture comprising the target compound and at least one of the reactants; (c) regenerating the loaded sorbent obtained in step (e), by flushing the loaded sorbent with the reactor outlet mixture originating from step (b), to obtain regenerated sorbent and an effluent comprising desorbed product; (d) separating the effluent originating from step (c) into a product stream and a reactant stream; and (e) a sorption step to obtain a loaded sorbent and a depleted mixture.