Study On Pyrolysis Characteristics And Products Of Pine Cone

Pinaceae plants are widely distributed in China.Pine seed is the fruit of Pinaceae.Pine cone is the shell of a pine seed.A large number of abandoned pine cone are produced in the process of pine seed processing.At the same time,the contradiction between energy and environment is prominent in China,and the development of biomass energy is one of the effective ways to alleviate this contradiction.In this paper,the pine cone was used as the research object,and the extraction method of phenylalcohol was used to separate the pine cone extract and the extraction residue.Based on the study of the pyrolysis characteristics of pine cone before and after extraction,the tube furnace pyrolysis experiment was carried out to explore the influence of the final temperature and rise rate on the solid,liquid and gas three-phase product yield and product characteristics of pine cone.The main research contents are as follows:（1）The pyrolysis characteristics and activation energy of pine cone are greatly affected by the extract.In the main pyrolysis range,the DTG curve of the raw material of the pine cone has two more shoulder peaks than that of the extraction residue.The two shoulder peaks are at 306℃and 450℃,respectively.Their formation is related to the extract.The change of activation energy of extraction residue is lagged behind that of pine cone material,and the activation energy of extraction residue is higher than that of pine cone material.（2）TG-FTIR analysis showed that,except for carbon dioxide,the maximum absorption peaks of all products in the pyrolysis process of pine cone raw materials are higher than that of extraction residue.There is a sudden drop of volatile product content of pine cone raw materials at about 450℃;When the pyrolysis temperature of extraction residue is higher than 450℃,the content of volatile products increases with the increase of temperature.The pyrolysis and volatilization of the extractives are almost completed at about 450℃,which makes the activation energy of the raw materials increase,and the content of the volatile products in the raw materials of the pine cone drop sharply.（3）The experimental results of pine cone pyrolysis show that,the yield of solid,liquid and gas from pine cone pyrolysis is 28.2%～45.7%,30.8%～44.9%,22.9%～26.8%,respectively.The increase of the final pyrolysis temperature and the heating rate will lead to the decrease of the solid product yield and the increase of the liquid and gas product yield;The lower calorific value of solid products increased with the increase of final pyrolysis temperature,from 28920 kJ·kg^-11 to 30460 kJ·kg^-1;The pH value of the liquid product increases with the increase of the final temperature and the heating rate,and the acidity decreases gradually;When the final pyrolysis temperature is 700℃and the heating rate is 20℃/min,the liquid products mainly contain acids,phenols,nitrogen compounds,aldehydes,alcohols and ketones,and the accumulated gas calorific value reaches the maximum value of 9770 kJ·m³;At the programmed heating rate of 80℃/min,the instantaneous calorific value of gas products rises first and then falls in the process of pine cone pyrolysis;During the experiment,the highest range of gas calorific value is between 638 s and 668 s,their calorific value is higher than 10834kJ·m³;At 668 s,the maximum calorific value of the gas is 11064 kJ·m³;In the pyrolysis process,the calorific value of the gas in the highest calorific value range is higher than that of the accumulated gas.