Complete recycling of waste edible oil has recently attracted considerable attention as a worldwide social problem. Production of a biodiesel fuel from used vegetable oil is considered an important step in reducing and recycling waste oil. This technology employs used vegetable oil as a potential renewable alternative resource to fossil diesel fuel, and the transesterification reaction is the usual process to obtain biodiesel. The objective of this work is to study the transesterification of waste oil with methanol in the presence of several Y-type zeolites with different Al 2 O 3 content. In this study, the reaction is carried out in a continuous tubular steel reactor using zeolite Y as catalyst, being tested at atmospheric pressure within a reactor temperature range of 200-476 °C and methanol/oil molar ratio of 6. The results show an important decrease of viscosity of the product obtained until values close to biodiesel specifications.

The use of a heterogeneous catalyst in the transesterification reaction of sunflower oil and waste oil for the production of methyl esters (biodiesel) has been studied. The basic hydrotalcite catalyst used showed a high activity for transesterification reactions in the operation conditions studied. The experiments were performed in a temperature range between 80 and 160 °C, in a batch reactor. The methanol/oil molar ratio in the reaction mixture and catalyst concentration ranges used were from 12:1 to 48:1 (mol/mol) and 3−12 (wt % of the initial vegetable oil mass) respectively. Calcined forms of the catalyst were tested. The catalyst was characterized with SEM, XRD, IR, and DTA-TG methods.

No abstract

No abstract

The transesterification reaction is the most utilized process to obtain biodiesel. Fried oil transesterification reactions with methanol have been studied using several zeolites Y and interchanged with CsCl and KOH. The reaction has been carried out both in a slurry reactor and a fixed bed catalytic reactor. The catalytic effects of zeolites have been tested within a temperature range of 60-476°C, 2.5-5% catalyst/waste oil weight ratio, and 6:1 - 100:1 methanol/oil molar ratio. Cosolvents (THF, n-hexane) in the reaction feedstock effect have also been studied as well as catalyst regeneration effects. Viscosity of both the oil and the transesterification reaction products was determined as an initial guide to investigate the degree of conversion to biodiesel as well as FAME content by GC. When interchanged zeolites are used conversions are improved, getting the best yields (98% FAME) for the Y756 zeolite interchanged with KOH. Viscosities of the reaction product obtained reached values next to diesel standard ones.