Study On Amine Selection And Mixture Ratio Optimization Of Mixed Amine Solvents Based On TEA For Decarbonization Of Natural Gas

As the natural gas demand is growing,the development and research of carbon dioxide removal technology is more and more important.Decarburization of natural gas is a key link in the process of pretreatment process.Amine decarbonization is widely used in natural gas pretreatment area.This method has attracted broad attention because of its advantages of strong absorption ability,quick reaction rate,wide application range,little gas loss,high purification degree,little solvent corrosion and low regeneration energy consumption.The property of absorbent influences purification effect of natural gas directly.There are many different kinds of distinctive absorbents,so choosing an efficient energy-saving and deep decarburization of amine absorbent formula is very important.Activated MDEA(methyldiethanolamine)amine solvents are widely used as absorbents at home and abroad now.In order to meet the demand of finding new cost-efficient and high-efficient absorbents,the paper selected mixed amine solvents with TEA(triethanolamine),which is also tertiary amine,as the main to study on optimization of amine solvent.Firstly,small-scale experimental research of TEA was performed to analyse absorption and desorption properties of TEA and determine suitable experimental operation parameters.On basis of that,study on mixed amine solvents with TEA as the main for formula optimization.In the research,TEA was the main composition and A,B,C,D,E were additives.Study effects of various additives on mixed amine solvents absorption and desorption properties and select A,C and E as optimum additives.Then,three different concentration of TEA+A,TEA+C and TEA+E mixed amine solvents were studied according to their absorption and desorption properties.Optimzed formulas were elected,which are 2mol/LTEA+1mol/LA,2mol/LTEA+1mol/LC,2.4mol/LTEA+0.6mol/LC and 2mol/LTEA+ 1mol/LE.Next,for these four mixed amine solvents,absorption and desorption experiments under cyclic conditions were conducted to evaluate absorption and desorption and cycling performance of each amine solvent comprehensively.The result showed that the optimal formula is 2mol/LTEA+1mol/LA.Finally,the formula was test by experiment and simulation,using middle-scale experiment device and HYSYS.The result of the verification showed that the formula is ideal.The results of this thesis is of high reliability and practical reference value.