Ex-Situ Catalytic Upgrading of Spirulina Platensis Residue Oil Using Silica Alumina Catalyst

Abstract

This paper discusses the effect of rising temperatures pyrolysis and the use of silica-alumina catalysts located in a dedicated chamber to improve the quality of bio-oil in terms of O/C, H/C, HHV values, oxygenated, and aromatic compounds. Pyrolysis is carried out in a fixed-bed reactor consisting of two reactors in series with an inner diameter of 40 mm (2 mm of thickness) and a total length of 600 mm. The upper reactor (R1) is filled with the SPR sample and the lower reactor (R2) is for silica-alumina catalyst being in placed. Pyrolysis is conducted at a temperature range of 300−600 °C by using a heating rate of 5-35 °C/min produced by controlled electrical heating and in the presence of silica-alumina catalyst (10−40 wt.%). The gas produced from pyrolysis is condensed to obtain a liquid consisting of two layers, the top layer of bio-oil, and the bottom layer of the water phase. From GC-MS, the data on mass percentages of C, H, O, N, and S of each compound in bio-oil is obtained, besides its mass percentages of aromatic and oxygenate compounds. The results shows that the pyrolysis at fairly high temperature (300-600 oC) without or with the catalyst, causes the increased values of H/C, HHV, and aromatic compound content, in contrast to the values of O/C and oxygenated compounds which is found decrease. Those respective increase are by 108.44, 34.20, and 54.32 %, conversely to the decrease value in O/C and compounds oxygenates of 54.98 and 65.86 %. The ex-situ catalytic by the use of silica-alumina catalysts (10-40 wt.%) seems to be an alternative method for obtaining the upgraded quality of bio-oil.