Recent trends for clean fuel production by deoxygenation of pure palmitic acid using Ni/C catalyst.

Abstract

Deoxygenation of triglycerides is one of key processes making possible a convenient production of high quality automotive fuels components (sulfur-, oxygen- and aromatics-free). This reaction was studied over non noble metal catalysts 20wt%Ni/C and performed in batch reactor system (autoclave) by using pure palmitic acid, n-hexane as a solvent and 200 psi pressure. The effect of different atmospheres (pure hydrogen, pure nitrogen, and mixture of 50 psiH2/150psiN2) and different temperature range (300 oC-350 oC) under a mixed atmosphere (50 psiH2/150psiN2) were studied in this paper. The main product was n-pentadecane (C15) which the catalyst Ni/C has lower cracking selectivity to light hydrocarbons. The total conversion of carboxylic groups of palmitic acid and the selectivity to C15 in case of pure nitrogen are (22.29% and 12.38%) respectively and in case of hydrogen they are (75.16% and 80.07%) respectively. In case of using H2/N2 as a mixture the total conversion and the selectivity are (81.18% and 75.32%) respectively for Ni/C catalyst. The total conversion increases from 81.18% to 99.99% by increase the temperature from 300 oC to 350 oC. The deoxygenation of palmitic acid over 20wt%Ni/C catalyst indicated that the high selectivity for n-alkane (C15) (75.32%) at 300 oC and reach maximum value (98.11%) at 350oC. Analysis of liquid products by gas chromatography (GC) was used to determine n-alkane (C15) yield and other products (isomeres, olefins and dimers). Insights pertaining to the reaction scheme and an assessment of the reaction products as liquid transportation fuels are also provided in this contribution.