Comparison of Ca-Based Commercial and Natural Catalysts Performance on Olive Pomace Pyrolysis Process

Abstract

Physicochemical treatment was applied with 20 mg/L alum to the marble processing effluents as 5 minutes 200 rpm mixing, 25 minutes 15 rpm mixing and 60 minutes settling and marble sludge (MS) was produced. Catalytic performance of MS in olive pomace (OP) pyrolysis process was evaluated and compared to commercial Ca(OH)2 since it mainly comprises of different AAEMs (especially Ca and its forms such as CaCO3, CaO) functioned as catalyst. Catalytic pyrolysis was conducted at 600°C and 5°C/min heating rate with 5% and 10% catalyst (MS or Ca(OH)2) dosages. Although both catalysts had important effect on pyrolysis product yields, Ca(OH)2 was found as good alternative for higher gas production and MS was introduced as better option for the higher char production comparing to the conventional OP pyrolysis. Pyrolysis biochars produced with MS were in higher thermal strength than the biochars generated with Ca(OH)2. Moreover, biooils of OP+MS include different organic compounds, such as 9 heptadecanol, 1-eicosanol, ethyl linoleate, ethyl oleate, addition to the compounds observed in pyrolysis liquids of OP and OP+ Ca(OH)2. All detected organic components have diverse usage areas. Ca(OH)2 provided more decrement in the percentages of oxygenated compounds as compared to the MS. Consequently, it can be stated that MS can be used successfully as an alternative to Ca-based commercial catalyst in OP pyrolysis.