Status : Verified
| Personal Name | Valero, Denise Patryzja T. |
|---|---|
| Resource Title | Hydrothermal Liquefaction of Polystyrene Cutleries: The Role of Water-Crude Glycerol Medium in Process Moderation and Liquid Product Yield |
| Date Issued | 4 June 2026 |
| Abstract | Polystyrene (PS) cutlery is a persistent single-use plastic waste with limited recycling value, requiring alternative valorization pathways. This study evaluated the hydrothermal liquefaction (HTL) of PS cutlery using a water–crude glycerol medium under lower subcritical conditions, focusing on the production and quality of the dichloromethane (DCM)-soluble liquid product. The condition parameters were temperature, residence time, and water–crude glycerol ratio at 240–270 ºC, 60–120 min, 1:1–1:5 v/v, respectively. Feedstock characterization confirmed that the feedstock was predominantly PS, with aromatic hydrocarbon functional groups, high volatile matter, negligible ash, and a calorific value of 39.592 MJ kg-1. Results showed that temperature was the primary factor affecting liquid product yield, while residence time and solvent ratio acted in a condition-dependent manner. The highest DCM-soluble liquid product yield of 50.11% was obtained at 270 ºC, 90 min, and 1:3 ratio. In contrast, the highest calorific value of 33.303 MJ kg-1 occurred at 240 ºC, 60 min, and 1:3 ratio, retaining about 84.1% of the feedstock energy content. Fourier transform infrared (FTIR) analysis indicated aromatic, aliphatic, and oxygenated functional groups, suggesting PS-derived liquid products with solvent-related secondary reaction products. Thus, the water–crude glycerol medium supported liquid product formation under moderated HTL conditions, but its effect was not a direct yield-enhancing main effect. The findings also highlight the need for compound-level analysis and control runs to verify solvent-specific effects on product composition and recovery within the present lower-temperature experimental scope and limitations. |
| Degree Course | MS Environmental Engineering |
| Language | English |
| Keyword | subcritical conditions; hydrothermal liquefaction; polystyrene cutlery; crude glycerol |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : I - Has patentable or registrable invention of creation.
Access Permission : Limited Access