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The conversion of poly(ethylene terephthalate) (PET) was analyzed in order to define the optimal conditions for the Bis(2‐Hydroxyethyl) terephthalate (BHET) yield as regards catalyst use (zinc acetate), glycol (ethylene glycol), reaction time and temperature. These conditions were optimized so as to decrease the consumption of catalyst and glycolytic agents aiming to extend the analysis to achieve continuous recycling at a greater scale. At the same time, an analysis of the activity of different catalysts (zeolites, acid, and basic resins) was performed; no BHET yields of commercial interest were obtained. The results indicate that a very small catalyst/PET mass ratio and a low glycol/PET ratio are necessary. The reactions were carried out at a temperature of 195°C and a reaction time of 1 h: under these conditions, BHET yield is 30% (starting from pure PET) and up to 88.2% (recycling oligomers plus pure PET). POLYM. ENG. SCI., 58:1500–1507, 2018. © 2017 Society of Plastics Engineers

Basic and acidic ion exchange resins were used as catalysts for the synthesis of biodiesel from soybean oil and methanol. The impact of reaction parameters like molar methanol/oil relationship, catalyst mass and reaction temperature were studied. The catalysts did not show deactivation and the reaction medium remained neutral. The performance of the resins was compared against reference catalysts (NaOH; MgO). A strongly basic macroporous resin was the most active catalyst and it was possible to reach 100 % selectivity to methyl esters. A series reaction mechanism was consistent with the evolutions of the intermediate reaction products.

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