CO2 capture technology for cement plantDate: 2019-06-21 Views:
CO2 is the gas with the greatest impact on climate change, raising global temperatures.Global climate change has a significant impact on the ecosystem, which threatens the survival and development of human society.According to statistics, more than 30 billion tons of C02 are released into the atmosphere every year, about 90% of which comes from fossil fuel intensive units such as power plants, cement plants, steel mills and refineries.With the development of social economy, the use and consumption of energy will increase, and the emission of C02 will increase. Therefore, all countries in the world are seeking various technologies to reduce the emission of C02.
1. Introduction to CSS technology
CCS is a source of CO2 emissions for collection, transportation and safety storage in somewhere, make the process of long-term isolation and the atmosphere, mainly by the capture, transport and sequestration of three links, and separation technology (large investment, high costs, recovery of CO2 emissions in our fleet) at the same time, the capture and sequestration technologies, with its large storage capacity, underground keep time, environment friendly, and many other advantages, is considered by many countries as one of the effective techniques to optional so far.
2. The application of CCS technology in cement plant
The application of CO2 capture after combustion has been widely studied in coal-fired or gas-fired power stations, but the application of CO2 capture in cement plants is rarely studied.The international energy agency's greenhouse gas research and development programme (GHG) has carried out two CCS studies at cement plants in the UK, including post-combustion CO2 capture and oxygen-rich combustion CO2 capture.The basic principle of CO2 capture after combustion is CO2 absorption by monoethanolamine after combustion.The cement plant can be equipped with such capture equipment by retrofitting existing buildings.
The following questions must be considered when installing the C02 capture system after combustion
The concentration of SO2 is critical for post-combustion capture techniques using amines because amines react with acidic compounds to form salts without dissociating themselves from the amine system.
As NOx in the gas will degrade in solvent in the single ethanolamine absorption system, the NOx content is also an important issue, more attention should be paid to the N02 reaction to form thermally stable salt.However, usually NO more than 10% of N02 is NOx and most of the rest is NO.
There is a large amount of dust in cement plant gas, about 3000mg/Nm3, which can be removed by electrostatic precipitator or bag precipitator.Dust reduces the efficiency of the amine absorption process.It is understood that dust levels must be below 15mg/Nm3 for efficient and economical post-combustion capture
3.4 gas cooling
In order to reach the ideal temperature of amine absorption system, the gas temperature must be cooled to about 50°C.
CCS technology in cement plant application prospects are considerable, continue to carry out in-depth research, the advantages of this technology will gradually reflect, it will be a good way to deal with the greenhouse effect.
However, the economic cost of these capture technologies is relatively high, and it is difficult to promote and apply these technologies in China. How to improve these technologies to reduce their cost is a key problem.