Solvothermal liquefaction and catalytic hydrothermal processing of plastics

This work examines the effect of catalysts in HTP of PP within the subcritical region; the catalysts tested, zeolite (HZSM-5) and potassium carbonate (K2CO3). Catalytic HTP of PP at 350 °C for 2 hrs with HZSM-5 and K2CO3 gave both gas yield of 95%. The components of the gas products were carbon dioxide, propene, 2-butene and pentane for reaction carried out with K2CO3 and carbon dioxide, propene and butene for reaction done with HZSM-5. Catalytic HTP of PP conversion as high as 99% using K2CO3.
Solvothermal liquefaction of PP was also carried with heptane and toluene to determine the effect of solvents in the liquefaction of PP. Three temperatures were tested (300 °C, 350 °C and 400 °C). The role of solvent was greatest at 400 °C. Another plastic examined in this work is nylon-6. The effect of catalyst (iron (Fe), zeolite (HZSM-5) and potassium carbonate (K2CO3)) in HTL of nylon-6 was tested. Fe and HZSM-5 gave 39% and 40% caprolaclam respectively.