Development Of Alkali-free Alkyl Naphthalene Sulfonate Flooding Agent

In this paper,methyl naphthalene and 1-deceneareused as raw materials,and the mesoporous silica supported aluminum chloride is used as solid catalyst to synthesize long-chain alkyl methyl naphthalenes.It is sulfonated with chlorosuflonic acid to synthesize alkali-free long-chain alky methyl naphthalene sulfonate.A series of performance investigations were conducted on the long-chain alkyl methyl naphthalene sulfonates and polymer in binary system.The aluminum chloride solid catalyst was prepared by impregnation method with silica as carrier and nitromethane as solvent.The conversion of 1-decene was used as an index to investigate the effects of carrier type,carrier particle size and carrier pretreatment temperature on the loading of aluminum chloride and the life of the catalyst.The optimum conditions for its synthesis were as follows: pretreatment temperature 200 ?,catalyst particle size 40-60 mesh.The conversion rate of 1-decene was used as the main index,and single-factor analysis was used to explore the molar ratio of 1-decene and methyl naphthalene,the amount of catalyst,reaction temperature,dropping time and reaction time on the alkylation reaction of1-decene and methylnaphthalene was investigated using the single factor analysis.The optimal alkylation conditions: the molar ratio of 1-decene and methyl naphthalene was 2.2:1,the amount of catalyst was 8 wt%,reaction temperature was 50 ?,dropping time was 60 min,reaction time was 30 min.The equilibrium interfacial tension as the evaluation index,the long-chain alky methyl naphthalene sulfonate was synthesized by sulofonation of long-chain alky methyl naphthalene with chlorosuflonic acid.Single factor analysis was used to determine the optimum sulfonation conditions: acid-oil ratio 1.7,sulfonation temperature 60 ?,sulfonation time 60 min,and aging time 40 min.The optimal sulfonation process conditions were determined using orthogonal experiments: acid-oil ratio 1.6,sulfonation temperature50 ?,sulfonation time 70 min,and aging time 45 min.Under the optimal sulfonation conditions,the equilibrium interfacial tension can reach 1.5×10-3 m N/m?In the alkali-free binary system where the concentration of long-chain alkyl methyl napthalene sulfonateconcentration is 0.1-0.3 wt%,and the polymer concentration is 2000mg/L.The hydrophilic lipophilic balance of the surfactant was adjusted with sodium chloride at a concentration of 0.6-1.2 wt%.Interfacial tension can reach 10-3 m N/m orde of magnitude in this concentration range.The binary system with the concentration of sodium chloride of0.6 wt% is more stable than the binary system with the concentration of sodium chloride of1.2 wt%.When the concentration of sodium chloride is 0.6 wt%,the water-out rate was low,and the total proportion of the particle size is less than 2 ?m is 68%.