Study On Preparation Of Anionic Surfactant With Heavy Naphthenic Acid By Catalytic Oxidation And Sulfonation

Petroleum sulfonate was widely used as enhanced oil recovery surfactant due to its strong interfacial activity,compatibility with crude oil,low production cost and simple process e.t.c.Xinjiang Karamay refinery outputed paraffin oil by vacuum gas oil 4 by-product massive of heavy naphthenic acids of which molecule contained hydrophilic carboxyl groups regarded as an inexpensive natural precious resource,but they had not been fully unexploited because of their low acid value,high molecular weight and viscosity e.t.c.In this paper,anionic surfactants with carboxyl acid groups and sulfonic acid groups were prepared by using heavy naphthenic acid as raw material from Karamay refinery by-product and evaluated its potential application in enhanced oil recovery.?1?In this paper,the catalytic oxidation reaction and sulfonation reaction were used to modify heavy naphthenic acids to synthetic carboxyl-sulfonate;The reaction condition were carried out in the presence of naphthenic acid salt as catalyst,O₂ as oxidant,low concentration of fuming sulfuric acid as sulfonation agent and 1,2-dichloroethane as sulfonation solvent to explore the influence of oxidation temperature T and oxidation time t on acid number,hydroxyl value and viscosity of raw oil before and after oxidation,and optimize the oxidation condition with the maximum yield of water/oil soluble carboxyl-sulfonate.It was found that the yield of water/oil solubility carboxyl-sulfonate was 76.13%and 37.19%respectively in the optimal oxidation condition,and the total yield of carboxyl-sulfonate was up to 113.32%.?2?In this paper,the composition analysis,basic performance test and the average structure determination of carboxyl-sulfonate were studied;It was concluded that the effective contents of water/oil solubility carboxy-sulfonate were 57%and 43%respectively by the two-phase titration method.This phenomenon was found that water/oil solubility carboxyl-sulfonate had better temperature-resistant properties,and the water solubility carboxyl-sulfonate had better salt tolerance than oil-solubility carboxyl-sulfonate,and carboxyl-sulfonate had a good tolerance to monovalent Na⁺,but had insufficient tolerance to bivalent Ca²⁺.It was showed that the carboxyl-sulfonate had two functional groups:carboxyl group and sulfonic acid group by FT-IR spectroscopy analysis,and calculated that the branching degree of carboxyl-sulfonate molecular structure was low by ¹H-NMR,and proved that the average molecular weight of water/oil solubility carboxyl-sulfonate were ???_W?28?5350.and ???_W?28?6173.respectively.The average structural formula of carboxyl-sulfonate was simulated simultaneously,and the reaction process of heavy naphthenic acids was speculated reasonably.?3?In this paper,the oil-water interfacial tension between kerosene,Kelian T71#oil,Jinzhou 57#oil and the complex system was investigated which contained carboxyl-sulfonate single agent with anionic surfactant PS,cationic surfactant CTAB and nonionic surfactant6501,and carboxyl-sulfonate single agent with alkali,polymer composition of binary?AS,SP complex system?,ternary complex system?ASP complex system?;The test result showed that the oil-water interfacial tension between carboxyl-sulfonate single agent and kerosene,Kelian T71#oil,Jinzhou 57#oil was reduced to the range of 10⁰mN/m,and the system of carboxyl-sulfonate and 6501 or CTAB could reduce the oil-water interfacial tension to the range of 10^-2mN/m¹0^-3mN/m which is ultra low interfacial tension range,the compound effect of KPS could not reach the range,Although binary complex system of alkali or polymer had effectively effect on reducing the oil-water interfacial tension,the compound effect of SP was far less than that of AS,besides the synergistic effect of alkali NaOH was better than that of weak base Na₂CO₃ in the AS complex system,and the complex effect of oil-solubility carboxyl-sulfonate was better than that of water-solubility carboxyl-sulfonate in ht SP complex system.In appropriate proportion,binary complex system AS or ternary complex system ASP could reduce the oil-water interfacial tension to the range of10^-2mN/m¹0^-3mN/m which meet the requirements of enhanced oil recovery on the interfacial tension of surfactant.