Methane Purification Adsorbent Heat Exchange
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methane purification and liquefaction technologies face high capital and operating costs due to inefficient removal of carbon dioxide and other impurities, particularly in distributed methane sources, which affects the competitiveness of compressed natural gas (CNG) and liquid natural gas (LNG) production.
Innovation Solution
A rapid temperature swing adsorption process using a series of three adsorbent beds with heat exchange between adsorbents, facilitated by a separate heat exchange fluid, to efficiently remove carbon dioxide and other impurities from methane streams, reducing capital and operating costs by reusing heat and increasing purifying capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional purification methods are used to remove carbon dioxide from methane streams, then carbon dioxide removal is achieved, but capital and operating costs increase significantly
Solution Approach 1:
The purification system is divided into multiple adsorber beds (typically three beds) that operate in sequence through different stages of the temperature swing adsorption cycle. Each bed handles a specific function (adsorption, heating, cooling, or purging) at any given time, allowing continuous operation while reducing overall system complexity and cost
Solution Approach 2:
The system employs periodic temperature swings rather than continuous temperature maintenance. Adsorbers are cyclically heated to desorb contaminants and then cooled to adsorb new contaminant loads, creating periodic action that reduces energy consumption and operating costs compared to continuous purification methods
2Manufacturing precision
If carbon dioxide is removed to required concentration levels (100 ppm) to prevent freezing in LNG equipment, then purification quality is improved, but processing time and energy consumption increase
Solution Approach 1:
The adsorber beds are pre-cooled to optimal temperatures before receiving methane streams, and pre-heated to desorption temperatures before contaminant removal. This preliminary preparation ensures that when the adsorption or desorption process begins, the beds are already at the correct temperature, reducing the time required to achieve target purification levels
Solution Approach 2:
The system dynamically changes temperature parameters during operation, switching between low temperatures for adsorption and high temperatures for desorption. This parameter change strategy allows the system to achieve high purification quality (100 ppm CO2 removal) while minimizing processing time by optimizing temperature conditions for each operational stage
3Use of energy by moving object
If heat exchange fluid systems are added to enable heat recovery between adsorbers, then energy efficiency is improved, but system complexity increases
Solution Approach 1:
A heat exchange fluid acts as an intermediary medium between adsorber beds, transferring thermal energy from beds being heated to beds being cooled without requiring direct thermal contact between the beds. This intermediary approach simplifies the overall system design compared to direct heat exchange methods while maintaining high energy efficiency
Solution Approach 2:
The heat exchange fluid system enables the adsorber beds to serve each other's thermal needs - one bed's waste heat becomes another bed's required heat input. This self-service arrangement reduces the need for external heating and cooling utilities, improving energy efficiency while the modular fluid exchange design keeps system complexity manageable
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 enhances the efficiency and cost-effectiveness of methane purification, allowing for the production of competitively priced CNG and LNG, especially in small-scale distributed methane sources, with improved methane retention efficiency and the ability to handle higher concentrations of contaminants.
Implementation Method 1
A rapid temperature swing adsorption process using a series of three adsorbent beds
Implementation Method 2
heat exchange between adsorbents, facilitated by a separate heat exchange fluid
Data Source
AI summary
Systems and methods for processing methane and other gases are disclosed. A representative method in accordance with one embodiment includes directing a first portion of a gas stream through a first adsorbent while exchanging heat between a second adsorbent and a third adsorbent. The method can further include directing a second portion of the gas stream through the third adsorbent while exchanging heat between the first and second adsorbents. The method can still further include directing a third portion of the gas stream through the second adsorbent while exchanging heat between the first and third adsorbents. In further particular aspects, the adsorbent can be used to remove carbon dioxide from a flow of methane. In other particular aspects, a heat exchange fluid that is not in direct contact with the adsorbents is used to transfer heat among the adsorbents.