Synthesis And Evaluation Of Pour Point Depressant Of Crude Oil

With the rapid development of economy,the demand for petroleum is rapidly increasing.To meet this demand,it is very important to adopt specific and higher technology for both recovery and delievery of crude oil.In fact,the properties of high wax content and high pure point for Chinese crude oil make it very difficult to recover and transport.The pour point depressant(PPD)played an important role in improving fluidity and decreasing viscosity for crude oil.In this paper,novel polymers have been designed,synthesized and evaluated as novel PPDs.First at all.novel polymers as PPDs were synthesized by copolymerized and modification.SMA and NMA copolymers were prepared by solution polymerization using maleic anhydride(MA)and styrene.N-vinylpyrrolidone(NVP)as monomers,with Azobisisobutyronitrile(AIBN)as initiator,toluene as solvent.After two copolymers were modified by stearic alcohol and stearic amine respectively,two novel PPDs were obtained.The pour point depressing efficiencies of the novel PPDs were investigated on Liaohe crude oil.Secondly,the constituent and preparation process of the novel PPDs were further optimized by the orthogonal experiment based on pour point depressant efficiency.The obtained optimal monomer composition of polymer is as follow:NVP:MA = 1:2,with AIBN of 1.0%of the total weight as initiator and the reaction time of six hours,using p-toluenesulfonic acid as catalyst.The optimized polymer was modified by stearic alcohol or stearic amine respectively,to prepare NMO-1 and NMO-2.Thirdly,the pour point depressing efficiencies of NMO-1,NMO-2 were evaluated in Liaohe crude oil.The results indicated that NMO-1 showed a significant superior pour point depressing efficiency compared with other five kinds of PPDs at concentration of 500 ppm,at 55?.Finally,the formulations composed of NMO-1 and other pour depressants(T8088B,SMO-2),surfactant(OP-4,Span-80),additive(toluene)were optimized on the base of pour point depressing efficiencies.The pour point depressing efficiencies can get better results respectively at 4:1 mass ratio of NMO-1 to T8088B,at 3:2 mass ratio of NMO-1 to SMO-2,at 3:2 mass ratio of NMO-1 to OP-4;at 2:3 mass ratio of NMO-1 to span 80;at concentration of 300 ppm NMO-1 added 5%toluene.Among these PPDs investigated,the best efficiencies was obtained at 3:2 mass ratio of NMO-1 to SMO-2 and the pour point of Liaohe crude oil can be decresed for 12?.