Estudo do processo de craqueamento térmico catalítico do sebo bovino para produção de biocombustível

Abstract

This work aims to study the use of beef tallow as raw material for the production of bio fuel through the process of catalytic thermal cracking reaction. Three catalytic thermal cracking experiments were carried out in a 143 liters reactor, operating in discontinuous mode at 450 °C at atmospheric pressure, using sodium carbonate (Na2CO3) as the catalyst. Two experiments were carried out with crude beef tallow (5 and 10 % Na2CO3 - mass/mass) and one with bovine tallow soap (5 % Na2CO3 - mass/mass). The organic liquid products obtained from the reactions were analyzed through physicochemical analysis and chemical composition. Fractional distillation was also realized in order to obtain fractions of petrol, kerosene and light diesel similar to petroleum. In order to follow the reactions over time, aliquots were withdrawn every 10 minutes up to a total of 10 samples with the first point collected within 30 minutes of reaction. For the collected samples physicochemical analysis and identification of the chemical compounds were realized. The results showed a tendency to obtain higher yields in organic liquid product (OLP) using the catalyst in larger quantities with the crude sample. The chemical identification showed the amount of hydrocarbons present (paraffins and olefins) ranging from 89.28 to 92.23 % and oxygenates (ketones) from 7.77 to 10.72 %. After the distillations, a predominance was observed in the diesel fraction (235-305 °C) while the petrol and kerosene fractions were lower, this behavior was repeated in all experiments. Regarding the samples collected over the time of the reactions it is possible to verify an increase in the acidity index and formation of oxygenates up to 60/70 minutes indicating the occurrence of the primary cracking and then, until the end of the reaction, a decrease in these values evidencing the secondary cracking.