Study On Salt-bath Pyrolysis Of Plastic For Recovery Of Fuel Oil

Today, on one hand, the increase of people's living standard and development of other industries are promoted by plastic industry, and on the other hand, waste pollution becomes more serious which does great harm to our surroundings. Liquefaction of plastic waste by pyrolysis for recovery of gasoline hydrocarbons can not only reduce the consumption of petroleum materials, but also be helpful for energy saving and environmental protection, which release the increasing pressure of energy shortage.In this paper, pyrolysis of plastic which composed of PE,PP,PVC,PS was carried out in molten ZnCl2. Characteristics of salt-btah and catalytic reforming pyrolysis were studied systematically. Results showed that the optimal conditions for the reaction was temperature between 440℃and 460℃, and mass ratio between ZnCl2 and plastic was 4︰1, temperature of catalytic reforming was 350℃with catalysis of 15 gram. The suitable temperature conditions in temp-programmed pyrolysis was 5～7℃/min of heating-up speed rate.Gas and liquid products were analyzed using GC and GC-MS with internal standard method. Propene content which reached 47.21%was high in gas product. The average mole mass of liquid product was between 90～280g/mol, in which the content of alkene, isoparaffin, cyclanes were high. The RON of gasoline calculated by Lovasic formula exceeded 83, which presented a tendency of fluctuation with the maximum value of 87.2 between 400℃and 500℃, and would reach 91.34 after catalytic reforming.TiO2/A12O3 and BuSnO catalysts were prepared using co-sediment and immersion method. TiO2/A12O3 catalyst had a good dispersibility after dehydration and calcination, and the specific area of it was between 265 and 389 m2·g-1. Both catalysts had week acid and basic active site with the ratios of 3︰1and 9︰1 respectively.Free radical and carboniue ion mechanisms of reaction appeared in salt-bath pyrolysis. After reasonable simplified assumption, a lump-kinetic model was set up including plastic, gas, liquid, wax, coke and intermediate product. The analytic and numerical solutions were put forward. The dependability and accuracy of this model were testified after comparison between experiment and calculated valve. Enzymatic degradation of plastic in organic phase was investigated preliminarily and thermal stability and devitalized kinetic of surfactant-coated enzyme was also studied. Lipase coated with epoxy propane modified surfactant showed definite activity and selectivity for degradation of PS in organic phase. Among four kinds of lipase, Porcine Pancreas lipase had the highest activity. It was found that the didodecanyl glutamate ribitol amide with 4 epoxy propane is the best surfactant. The optimal solvent and reaction temperature were benzene and 35℃respectively.