A New Technology Research About Ammonia Removal Of Carbon Oxide From Flue Gas Coupled With Chemical Production

In recent years, global climate change has become a global environmental problem which caused by excessive emissions, such as CO2 gas. It has brought the serious negative impact on social and economic development. Control and reduce CO2 emission to solve the greenhouse effect enhancement has important practical significance. To capture, store or use CO2 in the flue gas from power plant is considered to be more feasible measures to slow down CO2 emission in the near future. Ammonia carbon capture technology has many advantages, such as low investment cost, low corrosive and widely researched, but the existing method is just to use CO2 capture to be in storage, failing to effectively utilize CO2, which leads to the high cost of carbon capture. The road of pure carbon capture and storage is hard to work. To reduce decarburization costs, improve the utilization of CO2 resource is imperative ammonia method carbon capture technology.The mechanism of the experiment is ammonia carbon capture technology, in-depth studies which combining the conditions of the species analysis of ammonia solution absorbing CO2 in absorption tower, experiments of adding Na2SO4 into the solution to investigate the products conversion and output of ammonia absorbing CO2 and adding Na2SO4 to investigate the chemicals production in the carbonation tower, were conducted on the coupled chemical production in the process of ammonia carbon capture using self-designed experimental system. The effect on the species conversion process in absorption tower had been studied in terms of the basic experimental conditions: absorption analysis product species, Na2SO4 additive, carbonation tower technology, etc. And a detailed mechanism analysis and verification had been conducted by means of a variety of characterization methods. Under the condition of atmospheric pressure and using N2 as the carrier, the effect of factors such as temperature, p H on the distribution of product species in the absorption tower had been studied. The results showed that under the experimental conditions, after aqueous ammonia absorbed CO2, the product mainly is NH2COO-, the proportion of which will reach the peak when p H is around 10.5; while the higher of the value of p H, the more favorable for the formation of CO32-, conversely, the more favorable for the formation of HCO3-.Throughout the course of the reaction, the NH2COO- generating speed is significantly greater than the NH2COO- conversion speed, and the percentage of carbon atoms in NH2COO- is significantly greater than that in HCO3-. The absorption rate of ammonia carbon capture throughout the reaction is limited by the second-stage reaction, that is limited by the reaction rate of converting NH2 COOto HCO3-.The mechanism of how the additive Na2SO4 affects the conversion of the product was introduced, and the product conversion rate under the condition of different additives, different temperature, different ratio of R, different reaction time and different p H was studied through experiments. Studies have shown that the NH4HCO3 best conversion rate( η) can reach from 50% to 60% under the conditions of the concentration of NH4HCO3 is 2mol/L in the solution, the reaction temperature is 35℃~40℃, the value of the ratio(R)(NH4HCO3/Na2SO4) is 1/1.7, the value of p H is 7.5 and the reaction time is 40 min ~ 60 min.The carbonation tower technology was introduced, the effects of different temperature, different aqueous ammonia concentrations, different CO2 partial pressure and different liquid to gas ratio(L/G) on the carbon conversion rate and CO2 absorption had been investigated through experiments. The results showed that the carbon conversion rate reached 43.05% under the conditions of the temperature ranges from 30℃ to 40℃, the concentration of the aqueous ammonia reaches 2% in absorption solution, the ammonium carbonate solution concentration is 7.25mol/L, the concentration of sodium sulfate solution is 3.4mol/L, the flue gas CO2 partial pressure ranges from 15 KPa to 20 KPa, the liquid flow is 3L/min and the liquid-gas ratio(L/G) is 0.46.This paper proposes a new technology of the production of the new flue gas decarbonization coupling chemicals which provides the practical application of ammonia carbon capture with technical support.