Study On Oxidation Modification Of F-T Wax Without Catalytic And Preparation Of Special Wax

Fischer-Tropsch wax is a wax product obtained by reacting CO and H2 as raw materials,hydrofining and cutting.China’s Fischer-Tropsch wax has a large production capacity,but it is still at the primary stage.Its most widely used as an additive to improve the performance of special wax,which limits the application range of Fischer-Tropsch wax to a certain extent.The modified Fischer-Tropsch wax has good emulsifying and oil-soluble properties,which can be widely used in various industries,especially in the development of emulsified wax products with high added value.Therefore,directly using Fischer-Tropsch wax as raw material to produce special wax with high added value will be the only way for the development of Fischer-Tropsch wax industry.In this paper,Fischer-Tropsch wax was modified by non-catalytic oxidation to obtain oxidized wax with excellent performance,and the emulsified wax technology was systematically studied based on self-made oxidized wax.In this paper,acid value and saponification value were taken as the main indexes to evaluate the oxidation effect,and the catalytic oxidation modification of F-T wax was studied around oxygen-containing gas,reaction temperature and reaction time.The results showed that when O2 was used as oxidant,the optimum process conditions were reaction temperature 160℃,reaction time 6 h and O2 flow rate 400 mL/min.Under these conditions,oxidized wax with acid value of 46.02 mgKOH/g and saponification value of 96.58 mgKOH/g can be prepared.The oxidized wax has light color,light smell and high acid value and saponification value.Adding stearic acid with w=2.0%into the system can speed up the reaction to a certain extent and shorten the reaction time to 5 hours,but can not improve the acid value and saponification value of the final product.When O3 is used as oxidant,it is found that the oxidation effect is much stronger than that of O2.The acid value and saponification value of oxidized wax prepared under 3～4 hours are similar to those obtained by reacting O2 for 6～7 hours.The structure of Fischer-Tropsch wax and oxidized wax was characterized by infrared ATR.The results showed that oxygen-containing groups such as-COOH and-COOR were successfully introduced in the oxidation process.The effects of HLB,emulsifier type and dosage,emulsifying time,emulsifying temperature and shear rate on emulsion properties were studied by PIC phase inversion emulsification method.The results showed that the compound emulsifier with HLB of 12.0,w(O-15):w(Span80)=3:1,emulsifier dosage 8%,emulsifying temperature 90℃,shear rate 800rpm and emulsifying time 25 min.Under these conditions,stable emulsion with average particle size of 1.23 μm,viscosity of 58mPa·s and second-order dispersion can be prepared.The experimental results show that when the acid value of oxidized wax is about 30mgKOH/g,oxidized wax is easier to emulsify and the emulsifying effect is better.To sum up,oxidation modification of Fischer-Tropsch wax by non-catalytic oxidation method can obtain oxidized wax with excellent performance,which avoids environmental pollution caused by catalyst waste residue on the one hand and reduces economic cost on the other hand.Then,the formula of emulsified wax was studied with oxidized wax as the basic wax instead of paraffin wax,and a stable O/W emulsion was prepared.