Study On Purification Process And Energy Consumption Of Natural Gas Containing High CO₂by Alkanolamine Solutions

Natural gas with high CO2is a kind of unconventional gas, rational development andutilization can effectively reducing environment pollution and increase economic benefits.Purification treatment for natural gas with high CO2is different from sulfurous natural gas, inour country, it is still in early stages of development and utilization. In this paper, according tothe temperament characteristics of natural gas with high CO2, MDEA was chosen for gaspurification process, and the application of this decarbonization technology was studied.In this article, the performance of3kinds of activator which were added into MDEAsolution was discussed through experiments, including MEA、DEA、PZ. With the sameconcentration of amine solution, the CO2absorption properties of activated MDEA solutionswere analyzed; the experimental results showed that in the aspect of absorption capacity andabsorption rate, PZ had better performances than the other two activators, so PZ was chosento be the additive to activate MDEAsolution.Meanwhile, directing at the first integrated developed gas field with high CO2concentration in our country, this paper studied and evaluated the application of MDEAdecarbonization technology, the gas throughput and the circulating amount of amine solutionwas calculated. We also analyzed the gas and MDEA solution samples, the results show thatthe content of CO2in the decarbonized natural gas can meet the National standards, thehighest removing rate of CO2is92.16%, and the lowest is87.79%, and the averageremoving rate can reach90.36%, the decarbonizing effect is good actually. And the analysisresults of MDEA solution shows that the MDEA CO2removal unit runs smoothly andcorrosion occurs. The CO2removal unit was inspected at full load status, the operation indexeswere all in the acceptable range; The efficiency of the main equipments was analyzed too,and the operating efficiency of some of the pumps was found to be relatively low.This paper also focused on the energy consumption of MDEA decarbonizationtechnology, and we came to the conclusion that the energy consumption of CO2removal unitwas effected by several operating conditions, as the gas throughput, the content of CO2in thefeed gas, the pressure of absorption tower, the temperature in regenerator. And ultimately thepractical energy consumption of the MDEA CO2removal unit was analyzed, the results showsthat electricity consumption and the steam consumption respectively accounts for10.03%and89.97%of the total consumption, this indicates that the energy consumption of the MDEACO2removal unit is mainly reflected on the steam consumption during the regeneration ofrich amine solution.