Preparation And Application Of Biodiesel And Its Derivatives Alkanolamide

Biodiesel was synthesized by cottonseed oil, and the optimum condition was obtained for synthesis. The non-ion surfactant alkanoamide with the ultra low oil-water interfacial tension was synthesized by biodesel, and the optimal synthetic condition of alkanoamide was obtained too. The properties of the obtained alkanoamide, such as foamy ability, foam stability, wetting ability and emulsification ability were characterized. The ability of lowering oil-water interfacial tension was studied, surfactant flooding for the background of application.The biodesel was prepared by the reaction of cottonseed oil and methanol, with NaOH as catalyst. The results indicated that the suitable reaction condition was as the following: the molar ratio of methanol to oil was about 6 to1, the reaction time was 40~60min, reaction temperation was 50~60℃, the content of NaOH was 0.8wt% of oil. The yield of fatty acid methyl ester was over 93% under the above reaction condition. The refining methods of biodiesel and glycerol were obtained, and the composition of biodiesel was identified by GC/MS.Alkanolamide was synthesized by the reaction of biodiesel and diethanolamine, with NaOH as catalyst. The two-steps synthetic process was adopted. The appropriate condition in the first reaction step was as follows: the reaction was carried out at 140℃for 4hrs, and the molar ratio of biodiesel to diethanolamine was 1 to 0.8. After 4hrs reaction, the reaction temperature should fall to 70°C from 140°C. When the reaction temperature was 70°C, reaction got into the second step. In the second step, 0.9wt% KOH of biodiesel and diethanolamine which molar ratio to biodiesel was 0.3 to1 were added into the reactor for reacting 3hrs. The active content of alkanolamide could be over 92wt%. Alkanoamide which was synthesized in the above condition had good foam stability, wetting ability, emulsification ability and enhancing viscosity ability, but foamy ability was poor.The performance of alkanolamide for lowering oil-water interfacial tension was studied. The different systems were investigated, such as alkanolamide, alkanolamide/alkali, alkanolamide/SPS, alkanolamide and SPS/alkali. The results indicated that the oil-water interfacial tension could reach to 10-3mN/m level when the total ammount of alkanolamide and SPS was 0.5wt%, their mass ratio was 1 to 4, and the content of Na2CO3 was 0.7~1.5wt%. The ultra low oil-water interfacial tension of 8.2×10-5mN/m was obtained when the content of Na2CO3 was 1.0wt%.