Enhancement Of Reactor For Biomass Continual Carbonization Process

It is an immediate necessity to look for new sources of energy to replace fossilenergy with the deterioration of oil depletion and environmental degradation.Biomassbecomes a major concern as its pyrolysis process is a very old and effective way tosolve the problem and has been agreed by most people.Biomass carbongizationprocess whose target is getting solid carbon has been promoted by the great amountof study.It needs to be investigated continually for most of biomass carbonizationequipments are intermittent and it may lead to the problem of low productivity andimperfect utilization of pyrolysis products.This paper makes natural dried husk as test material.It contains cold conditiontest and pyrolysis test on the basis of continual carbonization equipment whichdesigned on its own.It summarizes the relevant laws on screw conveyor and verifiesadaptability of pyrolysis equipment.It also summarizes the law of power arrangementof pyrolysis equipment by building the relationship between temperature changes andheat changes.It provides some reference for the design of pyrolysis equipment in thefuture.Firstly,the flow mass of rotating segment feeder with seal cavity is50%less thanits theoretical value,besides,its limit rotational speed also has a big drop,The valuemay fall down to1/3of theoretical value.The screw feeder without shaft has a higherfill rate than the screw with shaft which has the same size with,its axial speedbecomes fewer than its theoretical value with the screw-pitch increasing.It hasformulated flow mass of screw with shaft and screw without shaft respectively,andthen got the best ksvalue:1.0for screw with shaft and0.85for screw without shaft.Then,the whole pyrolysis process can be divided into three section along axialdirection base on the husk pyrolysis process:drying section,pyrolysis section andprecipitation of carbon section,and all of the location of the three section almost donot change in the effective pyrolysis time domain.The continue type equipment canaccomplish husk’s continual pyrolysis process well.The pyrolysis time duration canbe as little as6min,unlike pyrolysis temperature which has great influence on pyrolysis products it has limited influence on pyrolysis products.Finally,the heat change of pyrolysis stage can be reflected by its temperaturechange,the whole process has two main heat adoption location,there is one heatadoption location that locating at initial stage, its quantity of heat adoption ismaximum due to most of cellulose and lignin decomposes.The heat release locationthat locates at latter end,but the quantity of heat release is limit and additional heatneeds to be replenished to counteract the heat dissipation caused by radiation.It turnsout the heat quantity of pyrolysis process is711.6kJ·kg-1that is got in the way ofanalyzing temperature change and building the relationship between temperaturechange and heat quantity change,it is the algebraic sum of heat quantity of eachlocation:the main heat adoption location is640.1kJ·kg-1,the secondary heat adoptionlocation is120kJ·kg-1and the main heat release location is48kJ·kg-1.The firsttemperature control point is set at3/4of the main heat adoption location, the secondtemperature control point is set at left of center of the secondary heat adoptionlocation and the third temperature control point is set at middle of spare location.Thedelivery effect of screw without shaft is7.9%stronger than screw with shaft.Sectionalheating mode is24%energy-saving than integral heating mode.