Production of Gas Oil Components from Waste Fats

Abstract

The modern-minded man has discovered that it is necessary to substitute a part of the fossil-derived energy sources with renewable energy sources to cover the energy demand of mobility, which sustains and accelerates the human society and economy. Nowadays, the transportation sector tries to achieve this through the development and utilisation of bio-derived motor fuels. In terms of Diesel-engines the biodiesel has been utilized in great volumes already, which is made from triglycerides via esterification (fatty-acid-methyl-ester, FAME). The FAME or biodiesel, due to its molecular structure, has some unfavourable properties. Therefore, it was necessary to develop a new generation of bio-derived motor fuel for Diesel-engines. The most promising product of these efforts is the bio gas oil, which is a mixture of n- and i-paraffins and obtained via hydroconversion of triglycerides. These compounds are the best components of conventional gas oils, too. Nowadays, mainly different vegetable oils are used as triglyceride source, but for the hydroconversion any feedstock with high triglyceride content can be used (e.g. brown greases of sewage works, used cooking oils, animal fats, etc.). The waste feedstocks can be especially beneficial. Hence, during the experimental work, our aim was to investigate the possibilities of the production of bio gas oil and bio gas oil containing gas oils on waste fat basis via the hydroconversion of waste rancid lard itself and as a 50% mixture with gas oils. We applied a CoMo/Al2O3 catalyst in sulphide and in nonsulphide state for our experiments. We studied the effects of the process parameters (temperature: 300–380°C, pressure: 40–80 bar, LHSV: 1.0–2.0 h-1, H2/feedstock ratio: 600 Nm3/m3) on the quality and yield of the products. The obtained main product fraction at the process parameters (360–380°C, 60–80 bar, LHSV: 1.0 h-1, H2/feedstock rate: 600 Nm3/m3) found to be favourable by us which were met the valid diesel gas oil standard EN 590:2009 + A1:2010 without additivation, except for its cold flow properties.