Synthesis Of Environmental Friendly Terpolymer Decalcifying Agent And Its Application For Removing Calcium From Crude Oil

Oil is the blood of industry. Since the 21st century, the growing demand for oil has led many oil resources to be over exploited, which makes oil’s calcium content higher and higher and greatly affects the oil processing. The currently decalcification technologies can’t well meet the requirements of industrial decalcification, such as overmuch dosage, not environmental friendly and low efficiency. Thus, the research and development of a efficient and environmental friendly crude oil decalcifying agent has important and practical significance. The purpose of this paper is to explore a new type of environmental friendly crude oil decalcifying agent. Based on the comprehensive reference and research on the related literature, we successfully synthetized two types of economical, environmental friendly, high efficiency chelating decalcifying agents:itaconic acid-sodiumallylsulfonate-hydroxyethylacrylateterpolymer (IA-SAS-HEA) and acrylic acid-itaconic acid-allypolyethoxy maleic carboxylate (APEY-IA-AA) terpolymer. At the same time, the structure of these two kinds of polymers are characterized by fourier-transform infrared (FT-IR), and 1H-NMR, Also, the degree of copolymerization is characterized by bromine number (BV). Then, the synthesis conditions of each polymer and the desalting conditions are changed to investigate their influence on decalcifying performance.For IA-SAS-HEA, according to the free radical copolymerization, we successfully synthesized this polymer and used different kinds of methods to verify the polymerization conditions. Aiming at a higher rate of decalcified, the synthesis conditions and decalcified conditions of the IA-SAS-HEA were explored, the best synthesis condition is:the IA-SAS-HEA monomer mole ratio of 3:1:1, the reaction time is 4 h, the reaction temperature is 80℃, and the dosage of initiator to monomer 10% of the total mass; While the LuNing crude oil was considered as the calcium application sample, the best decalcified application condition is:the dose of calcium quality ratio of 3:1, primary and secondary electric temperature is 130℃ and 125 ℃ respectively, thermal response time to let stand for 15 minutes. The results of the experiments show that the chelating decalcifying agents: IA-SAS-HEA under the best conditions, the efficiency of the removal of the calcium in crude oil is best, the decalcification rate can reach 79.7%.For APEY-IA-AA, we first used maleic anhydride of allylpolyoxyethylene ether (APEG) for sealing and modification, synthesized maleic anhydride modified allyl polyethylene ethoxy ether carboxylic acid monomer (APEY) reaction, then, used the method of free radical copolymerization to successfully synthetize the APEY-IA-AA, finally, the fourier-transform infrared (FT-IR),1H-NMR and other methods were used to verify the polymerization conditions. Aiming at a higher rate of decalcified, we explored the synthetic conditions and decalcified conditions of the APEY-IA-AA. The best synthesis condition is:the APEY-IA-AA monomer molar ratios of 1:2:1, reaction time is 3 h, the reaction temperature is 85℃, and the dosage of initiator to monomer 6% of the total mass. While the LuNing crude oil were considered as calcium application sample, we explored the best decalcified application condition is:the dose of calcium quality ratio of 4:1, primary and secondary electric temperature is 135℃ and 130℃ respectively, insulation static response time for 20 minutes. The results of the experiments show that the crude calcium APEY-IA-AA under the best conditions, the efficiency of the removal of the calcium in crude oil is best, the decalcification rate can reach 78.1%.