Coprocessing waste plastics with coal and petroleum resid into liquid chemical feedstock as a tertiary recycling

Coprocessing of waste plastics with coal and petroleum resid was investigated to determine the effect of resid on reactivity and conversion. This study includes five experimental chapters: (1) use of petroleum resid as a solvent in coprocessing waste plastics with coal and its feasibility and synergistic effect; (2) details of the effect of varying the reaction time on systems including LDPE; (3) factorial design to determine the significance of the factors such as catalyst type, time, and temperature on the product distribution and boiling point distribution of hexane solubles from reactions; (4) use of a two-stage process to which fractional factorial design was applied, and consists of two sets of experiments, which include the selection of reaction temperature and time and reactant loading sequence and a detailed study of the effect of coal content and H{dollar}sb2{dollar} pressure on the conversion of coal and LDPE; (5) fractional factorial design of two-stage coprocessing using different kinds of reactants. Summaries of these five experimental chapters follow.; First of all, the feasibility of using resid as a solvent in coprocessing waste plastics with coal was determined using the defined coprocessing effect factor {dollar}(fsb{lcub}i{rcub}).{dollar} Increasing LDPE reaction times from 60 to 300 min resulted in an increase of conversion from 39.5% to 90.2%. After 360 min the conversion declined to 70.9%. Similar results were obtained with the LDPE and coal reactions; increased reaction time resulted in increased LDPE conversion as well as increased overall conversion. The results from the catalyst study showed that catalytic coprocessing of LDPE, coal, and resid was affected by the type of catalyst used. Introduction of 10 wt% hydrocracking catalyst to NiMo/Al{dollar}rmsb2Osb3{dollar} increased conversion and improved the overall product slate. The hydrocracking catalysts themselves were most effective for converting the solid reactants to THF soluble material and producing lower boiling point products. By contrast, the different types of catalysts gave very similar results in LDPE/coal reactions and did not produce substantial improvements in conversion.; From an analysis of the variance of the first set of experiments of fractional factorial design of two-stage coprocessing for reaction parameter selection, extraction after the first stage turned out to be significant for all gas, hexane solubles (KXs), and conversion, with a confidence level of 97.5 {dollar}sim{dollar} 99%, while no two-factor interactions investigated in this study had a significant effect on the response variables.; The weight percent of coal present in the reaction had an effect on the amount of hexane solubles with a 99% confidence level. Hydrogen pressure in the second stage affected the amount of gas produced, while hydrogen pressure in the first stage affected the amount of hexane solubles produced with 90% confidence. Interactions of weight percent and hydrogen pressure at the second stage did not affect the response variables. Low H{dollar}sb2{dollar} pressure at the second stage with a high coal weight percent was the worst case for producing HXs. The effect of catalyst sequence and types of reactants turned out to be significant for HXs and conversion.