Co-pyrolysis and catalytic co-pyrolysis of Enteromorpha clathrata and rice husk

Catalytic co-pyrolysis process of Enteromorpha clathrata (EN) and rice husk (HU) was studied in a fixed bed reactor with ZSM-5 and MCM-41 catalysts at 550 °C. The yields and product distribution were compared when EN, HU and different mass ratios of EN and HU were pyrolyzed with or without catalysts. Bio-oil products were analyzed by Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry (GC–MS) and bio-char products were analyzed by X-ray photoelectron spectroscopy. Under co-pyrolysis conditions without catalysts, the experimental yield of bio-gas was higher than the theoretical. In contrast, the yield of bio-oil was lower than the theoretical. In the catalytic pyrolysis, ZSM-5 significantly improved the yield of bio-oil and reduced the bio-gas product. However, the effect of MCM-41 on the yield of the pyrolysis products was weaker than that of ZSM-5. In the GC–MS analysis of bio-oil with catalysts, ZSM-5 showed a catalytic effect on the decomposition of hemicellulose and protein. The protein was further cracked, and the relative content of hydrocarbon component also increased. With MCM-41 catalyst, there was significant catalytic effect on lignin and lipid, and the result showed that MCM-41 had a further catalytic influence in the synergetic effect of co-pyrolysis.