Study On Optimization Of Energy Consumption For Natural Gas Purification Station In Changling

A study on current technical status and existing problems in removing CO2 from CO2-rich natural gas was carried out. Then new directions of the research on activator, optimization of operating process and parameters, pressure swing adsorption and membrane separation integrated technology were proposed in order to form a series of matching technology suitable for that natural gas, and boost its development efficiently in China.The active MDEA method is one of the important methods in removing CO2 from CO2-rich natural gas and the technology is mature. However, further optimize the technological process and operation parameters are still need in order to reduce the energy consumption and improve economic efficiency. In this article, the research on decarbonization purification plant for CO2-rich natural gas in Changling gas field was carried out and the economic running index was analyzed. The results showed that the comprehensive energy consumption could be used as the optimization goal. The actual unit comprehensive energy consumption was 1.028×104 MJ/104 natural gas which was higher than the design value. Therefore, the purification plant had much room for energy saving, and the potential of energy efficiency should be tapped according to its own characteristics. Then Aspen HYSYS software was used to simulate the process, and comparison to the plant data and simulated data was done to test the accuracy of two models. The results showed that simulation results by Li-Mather model were much closer to the production data, so Li-Mather model was selected for the simulation. And the influences of the method and technical process to take off CO2 from natural gas on energy consumption was analyzed.At the same time, this paper analysed the impact of operating conditions on energy consumption in aMDEA decarbonization process for CO2-rich natural gas. These operating conditions discussed included feed gas temperature, feed gas processing capacity, lean MDEA flow, number of absorber trays, absorber pressure, absorber temperature and number of stripper trays. Single factor experiments were conducted to select key parameters and the optimal ranges in the process of aMDEA aqueous solution used to remove CO2 from CO2-rich natural gas. Finally, experiment design and analysis of experimental results were carried out by the response surface method. The optimum conditions were determined to be 25℃ feed gas temperature, 82.12% feed gas processing capacity, 16150 kmol/h lean MDEA flow, 4.21 MPa absorber pressure, 54.8℃absorber temperature and 19 number of stripper trays. The total energy consumption was 3.55315×107 kJ/h, and the relative error between experimental value and prediction value was only 0.02%. Compared to the actual energy consumption in the present process, the total energy consumption was reduced by 26.97% after optimization.