Amine Emission Control in CO2 Capture via Washing Liquid Circulation
Solution Overview
Problem
Carbon dioxide capture systems using amine-based solutions release amine compounds into the atmosphere along with decarbonated combustion exhaust gases, posing environmental concerns due to the large amounts of amino group-containing compounds being emitted from thermal power plants.
Innovation Solution
A carbon dioxide capture system that incorporates a first washer to wash the combustion exhaust gas with a mist of a cleaning liquid, capturing the amine accompanying the gas, and a cleaning liquid mist capturer to further capture any mist of the cleaning liquid, thereby reducing the amount of amine released into the atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a carbon dioxide capture system uses an amine-based absorbing liquid to separate carbon dioxide from combustion exhaust gas, then carbon dioxide capture efficiency is improved, but amine compounds are released into the atmosphere causing environmental pollution
Solution Approach 1:
A washing liquid circulation system is introduced as an intermediary between the absorption column and atmosphere. The washing liquid (water or weak acid solution) absorbs amine compounds from the decarbonated combustion exhaust gas through gas-liquid contact in a washing section, preventing amine emission while maintaining carbon dioxide capture efficiency
Solution Approach 2:
The system recovers amine compounds by circulating the washing liquid through a regenerator. The washing liquid that has absorbed amine is heated to release the amine, which returns to the absorbing liquid system, while the cleaned washing liquid is reused. This closes the amine material loop and prevents atmospheric emission
2Object-generated harmful factors
If a washing section is added to remove amine from combustion exhaust gas, then amine emission is reduced, but pressure loss increases
Solution Approach 1:
The system uses hydraulic principles by circulating washing liquid through pumps and using gravity-driven flow in the washing section. The washing liquid is sprayed into fine droplets to maximize gas-liquid contact area, efficiently removing amine with minimal pressure drop across the washing section
Solution Approach 2:
The system changes the physical state of the washing liquid by spraying it as fine droplets rather than continuous flow, increasing surface area for mass transfer. The temperature and flow rate of the washing liquid are optimized to achieve effective amine removal while minimizing pressure loss
3Object-generated harmful factors
If a washing liquid circulation system is introduced to capture amine, then amine removal efficiency is improved, but device complexity increases
Solution Approach 1:
The washing liquid circulation system serves multiple functions: it removes amine from exhaust gas, provides a heat exchange medium, and acts as a transport vehicle for recovered amine. The regenerator performs both amine release and washing liquid cooling functions, reducing the need for separate systems
Solution Approach 2:
The washing section is integrated with the existing carbon dioxide capture system architecture. The regenerator combines amine recovery from washing liquid with cooling of the washing liquid for reuse. The washing liquid circulation system merges mass transfer (amine removal) with heat transfer functions
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
The system effectively captures and reduces the release of amine compounds into the atmosphere, improving the environmental impact of carbon dioxide capture processes by enhancing the removal efficiency of mist-like amines and minimizing pressure loss and operational costs.
Implementation Method 1
an absorption column that causes carbon dioxide contained in a combustion exhaust gas to be absorbed into an amine-based absorbing liquid
Implementation Method 2
a regeneration column that heats the absorbing liquid (rich liquid) absorbing the carbon dioxide supplied from the absorption column to release the carbon dioxide from the rich liquid
Implementation Method 3
a first washer configured to wash the combustion exhaust gas discharged from the carbon dioxide capturer with a mist of a first cleaning liquid sprayed by a spray to capture the amine accompanying the combustion exhaust gas
Data Source
AI summary
A carbon dioxide capture system according to the embodiment includes: a carbon dioxide capturer configured to cause a carbon dioxide contained in a combustion exhaust gas into an absorbing liquid containing an amine; a first washer configured to wash the combustion exhaust gas from the carbon dioxide capturer with a mist of a first cleaning liquid sprayed by a spray to capture the amine contained in the combustion exhaust gas; and a cleaning liquid mist capturer configured to capture the mist of the first cleaning liquid contained in the combustion exhaust gas from the first washer. The first washer has a receiver arranged below the spray, and a washing-capturing space arranged between the spray and the receiver. In the washing-capturing space, the mist of the first cleaning liquid comes into gas-liquid contact with the combustion exhaust gas while freely dropping.