CFD Simulation Of Carbon Dioxide Capture Reactors For Architectural Materials Application

In recent years, research has shown that in the field of civil engineering, carbon dioxide becomes a new pattern additive material to reform cement-based materials performance such as concrete, cement tile and cement brick. Combination building material has excellent performance, and usage of carbon dioxide can significantly reduce greenhouse gas emission. Carbon dioxide in atmosphere is difficult to obtain, laboratory pr oduction will increase the carbon dioxide distribution to pollute the environment. However, how to capture carbon dioxide effectively from emission sources will directly affect the usage of new combination building materials in civil engineering. The fossil fuel consumption is the main stationary source of the carbon dioxide emission. We can capture carbon dioxide from coal-fired flue gas to reform cement-based building materials performance. It also effectively control emission o f carbon dioxide in the atmosphere and mitigate greenhouse effect. The present study does some research on carbon dioxide capture from coal-fired flue gas and uses CFD to simulate the carbon capture process. T his research lays the foundation for the widely use of carbon dioxide in c onstruction industry.Three different approaches exist to mitigate carbon dioxide emissions: pre-combustion, oxy-fuel technology and post-combustion carbon capture. The most commercially viable approach to be fitted in fossil fuel power plants is the post-combustion capture which absorbs carbon dioxide from the flue gas using chemical reaction technology.The present study uses CFD to deal with numerical modeling and simulation of carbon dioxide capture from flue gases by aqueous ammonia as an absorbent. This method belongs to chemical reaction absorption. A representative elementary unit is created to study the absorption process. The simulations include single-phase gas flow, gas-liquid multiphase flow and gas-liquid absorption process within chemical reaction. We can get pressure drop data from single-phase gas flow simulations, which can aid the optimization of future structured packing designs. From gas-liquid multiphase flow simulations, we can find liquid phase flow distribution on wall surface, from film flow, rivulet flow to droplet. T his is helpful to gas-liquid simulations with chemical reaction and results are found to be consistent with the reported experiment study. Gas-liquid absorption process within chemical reaction is a complex process. Combine species transport model, general finite-rate model with chemical reaction kinetics, we establish the chemical reaction model and get CO2 absorption rate from mole fraction of production NH4HCO3. On the basis of previous model, we consider the mass transfer from gas phase to liquid phase in carbon dioxide capture. Programs are compiled to simulate mass transfer process. At last, a preliminary analysis is made for these two model results. On the basis of previous simulations, various operating conditions including liquid inlet flow, gas inlet flow, CO2 inlet mass fraction, ammonia concentration and pressure on CO2 capture process are examined. T he modeling results are found to be consistent with the reported experiment on CO2 absorption rate at different operating parameters.