Research On Pyrolysis And Gasification In Fluidized Bed And Ash Fusion Characteristics Of Herb Residue

Rational utilization of herb residue related to the sustainable development of Chinese medicines industry. Pyrolysis and gasification as a transformation form for the treatment of biomass can be applied to medicine residue, which can not only reduce the environmental pollution, but also produce valuable feedstock for synthesis gas. In this paper, after paralysis and carbonization of herb residue with fast pyrolysis device, we did gasification experiments of carbonized product of residue in the micro fluidized bed reaction analyzer(MFBRA) and researched on gasification reaction kinetics of char with CO2,at the same time, we studied the composition and melting characteristics of herb residue ash with SEM?XRD and XRF.The results show that:(1)Under N2 atmosphere, with the increase of pyrolysis temperature, yield of the solid product char of herb residue pyrolysis reduced, semi-coke gasification activity increased, the gas yield increased, and H2 among the product gas is significantly increased, tar yield and content of light components in the tar first increased and then decreased.(2)Under air atmosphere and constant temperature, with the excess air ratio(ER)increasing, yield of the solid product char of herb residue pyrolysis and tar decreased,gas yield increased significantly, and CO2 among the product gas significantly increased, CO, CH4 and H2 decreased slightly; Semi-coke gasification activity is higher than N2 atmosphere, the content of light components in the tar is less than N2 gas.(3)Under steam-containing atmosphere, with the increasing of steam, yield of tar,gas and char of the herb residue pyrolysis did not change significantly, wherein the gas yield increased slightly, and the gasification activity of semi-coke increased, light components in the tar increased. Experimental results show that the suitable pyrolysis conditions of herb residue: 600?, ER=0.1, S/B= 0.15.(4)With the gasification temperature, the semi-coke gasification reaction time was significantly shortened; The reaction rate decreases with the increasing of conversion rate. Based on condensation model, activation energy in the gasification reaction of semi-coke from the herb residue pyrolysis and CO2 is 120.3k J / mol.(5)Herb residue ash in air atmosphere sintered at 1200?, but other atmosphere including CO2, H2 O and CO sintered at 1150?; under four kinds of atmosphere ash sintering occurred in the degree of shrinkage over 50%; the composition of residue ash is mainly quartz and silicon eutectic, together with alkali metal or alkaline earth metal oxide, then magnesium eutectic with silicon or other substances formed after1100?; the mix ash sample added quartz sand was not found shrinkage within1300?.