Pyrolysis and catalytic steam gasification of olive oil waste in two stages

Abstract

A study of the pyrolysis and catalytic gasification of a waste from the extraction of olive oil has been carried out. The work objective was to characterize the solid and gaseous phases generated in the process for their possible utilization in energy generation. The experimental system consists of two cylindrical stainless steel reactors connected in series. A conventional pyrolysis is produced in the first reactor. In the second reactor, the gases and liquids generated in the first one pass through a dolomite catalytic bed where the cracking of the heavier components is produced. Also, in this second reactor, a steam stream is continuously introduced. The influence of temperature (500-700 oC), quantity of catalyst (25-100 g) and steam flow rate (0-1.40 mL/min) has been determined. Also, the dolomite effectiveness as catalyst was evaluated For this motive, experiments, without reactivating dolomite, were carried out (0-6 runs), and the yields of solids, liquids and gases were determined. An increase in reaction temperature leads to a decrease in solid and liquid yield and to an increase in the gas phase yield. The presence of catalyst and the quantity of the same, originate an important decrease in the liquid phase yield and a high increase in the gas phase yield, especially important in the case of hydrogen. On the other hand, the catalyst is very stable and does not lose activity during at least six cycles of reaction. The presence of steam, increase the yield of hydrogen, but the increase of the steam flow rate, do not generate significant changes in the products distribution.