Experimental Study On Pyrolysis of Rice Straw Catalyzed By CaO/Al2O3-Phosphate Mixture

Abstract This paper studied the synergistic effects of CaO or Al2O3 and three potassium phosphates (e.g., KH2PO4, K2HPO4·3H2O and K3PO4·3H2O) in the rice stalk pyrolysis through pyrolysis-gas chromatography-mass spectrometer (Py-GC/MS) experiments. The results show that after co-catalyzed by CaO/Al2O3 and potassium phosphates, the total contents of phenols, aldehydes, acids, LG from most samples decrease and those of ketones increase compared with those catalyzed by potassium phosphates alone. CaO/Al2O3 and potassium phosphates show synergistic effects in the regulation of the types or contents of phenols, ketones, aldehydes, etc. and are suitable for the production of ketone-rich bio-oil. Dehydration reactions, etc. are further promoted under the co-catalysis of the two catalysts, and some phenols can be converted to benzene products, etc. The contents of acetic acid can decrease to 0. For 50% K3PO4.3H2O impregnated sample, the yields of furans reduce sharply after CaO addition. For most impregnated samples except 50% K2HPO4·3H2O sample and 30%, 50% K3PO4.3H2O, the contents of total furans and furfural increase after Al2O3 addition.