Research On The Pyrolysis Of Nutshell Biomass And Its Products Analysis

Nut Shell biomass as an important component of biomass resources is always discarded or burned to produce heat, which is not really to achieve its efficient utilization. Therefore, in this study it is hoped that through the research of component analysis, thermal gravimetric analysis, pyrolysis and catalytic pyrolysis of seven kinds of nutshells including Camellia shell, Coconut shell, Tung shell, Walnutshel shell, Chestnut shell, Pistachio shell, Cashew nutshell and Pinus massonianathe, suitable Nutshell biomass and the catalyst that can be used to produce chemicals with higher content can be found preliminarily, which can lay the foundation for the reuse of Nutshell biomass.The major components of the six kinds of nutshell except Cashew nutshell are cellulose, lignin and hemicellulose, and the total content of which is more than 73%, while the total content of which in Cashew nutshell is only 47.41%. There are severe mass loss and large mass loss peak during temperature range from 200℃ to 410℃ during the whole pyrolysis process of nutshells, and there appear more than one pyrolysis peak in the DTG diagrams of six nutshells except Tung shell, and there appear obviously pointed pyrolysis peaks on the left of the maximum pyrolysis peaks of Coconut shell, Camellia shell, Pistachio shell and Cashew nutshell, while there appear acromion pyrolysis peak on the left of the maximum pyrolysis peaks of walnut shell and chestnut shell. The pyrolysis kinetic equations of nutshells meet first-order kinetic equation, and the pyrolysis activation energy is between 40-85 Kj/mol. The correlation between the maximum pyrolysis peak temperature and the total content of lignin and cellulose in nutshells is more significantly positive (R=0.899,P=0.005<0.05). The correlation between the left-side pyrolysis peak temperature and the hemicellulose content of nutshells except Tung shell is significantly positive (R=0.836, P=0.04<0.05).The MWL of seven Nutshells and MWL of Pinus massoniana were used as raw materials for pyrolysis, and the structure and content of pyrolysis products were analysised by Py-GC-Ms under different temperature conditions. The results showed that the main component in the pyrolysis products of all MWL is polyphenols, and the content of 2-Methoxy-4-ethenylphenol is 13.62%, and the total content of polyphenols from the MWL of Camellia shell is about 41%. In the pyrolysis products of Coconut shell MWL the content of 2-Methoxy-4-ethenylphenol is about 9.79%, while the total content of polyphenols is 51.21%. In the pyrolysis products of Pistachio shell MWL, the kinds of pyrolysis products whose structure can be identified are relatively less, and the content of 2,6-Dimethoxy-4-allylphenol is about 18.84%, while the total content of polyphenols is only 29.57%.The Camellia shell MWL was used as raw material, and the silicon dioxide, titanium dioxide and aluminum oxide was used as catalyst respectively for catalytic pyrolysis of Camellia shell MWL at 500℃, then its pyrolysis product was analyzed. Comparing with the pyrolysis products of the Camellia shell MWL without catalyst, the major composition of pyrolysis products including the component kinds and the concentration changes great, and the content of 2-Methoxy-4-ethenylphenol reduced from 13.62% without using catalyst to 8.31%,8.77%,8.58% respectively with catalytic pyrolysis, while the total content of acids and the total content of ketones changed a little after the catalysts were used. The total content of polyphenols in the product of catalytic pyrolysis with silicon dioxide, titanium dioxide and aluminum oxide as catalyst is 41.37%,47.06% and 41.99% respectively, while that without catalyst is 41.56%, which indicates that silicon dioxide and aluminum oxide have little influence on the total content of polyphenols, while the titanium dioxide has certain influence on the total content of polyphenols during the process of catalytic pyrolysis.