Pyrolytic Gasification of Polyethylene Pellets in a High Temperature Fluidized Bed with a Conical Distributor

锥形分布器高温流化床中聚乙烯颗粒的热解气化

基本信息

批准号：
06650887
负责人：
AKEHATA Takashi
金额：
$ 0.64万
依托单位：
SCIENCE UNIVERSITY OF TOKYO
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

As one of the promising methods for reusing plastic waster. a pyrolytic gasification in a fluidized bed reactor has been proposed. However, there is little information on the design of conical-distributor-equipped fluidzed bed for plastic waste gasification. In this study, the pyro-lytic gasification of polyethylene (HDPE) pellets by partial combustion method was carried out in a conical distributor equipped fluidized bed, wall temperature of which was mantained mainly at 600ﾟC electrically.Using a cold fluidized bed model, silica sands behavior in the bed was investigated. The conical distributor gave a good fluidization silmilar to a spouted bed. The amount of sands flying over the densely-fluidized bed was measured and expressed by a function of air velocity.The perfoemance of gasification in the present apparatus was found to depend much on the balance between HDPE feed rate and air flow rate. The optimum air ratio to give both a product gas of high lower heat value and a tolerably small amount of oil and char, was found to be 0.2 to 0.3. The influence of the wall temperature of reactor was much less than the former two factors. The effect of silica sand amount was not so significant but the bed height/column diameter ratio of 1.2 to 1.7 was found advisable. Since the heat losses from the reactor system in all runs were found as large as about 90%, in order to suppress heat losses both operations without preheating of fluidizing gas and an operation in which all the electric heatings were cut after partial combustion started were tested. For both tests good results were obtained. For the latter, the operation could be continued for more than 2 hours after shutting off the heater and the heat loss of the run was reduced to 72%.

作为重复塑料废物的承诺方法之一。已经提出了流化床反应器中的热解气化。但是，几乎没有关于临床分布器配备流体床的设计的信息。在这项研究中，通过部分混合方法在临床分配器中进行了聚乙烯（HDPE）颗粒的热解气化，该方法在配备的流化床床中进行了壁温度，主要在600°C上进行了壁式的壁温度。使用冷流利的床模型，研究了床的硅粉行为。锥形分配器给喷出的床提供了良好的流化二氧化硅。测量并通过空气速度的功能测量并表达了飞越纯净的床的沙子量。发现当前设备中气化的渗透在很大程度上取决于HDPE进料速率和空气流量之间的平衡。最佳空气比给出高较低热值的产物气体和可耐受性的小空气比反应堆的壁温度的影响远低于前面的两个因素。二氧化硅砂量的效果并不是那么重要，但是发现床高/柱直径比为1.2至1.7。由于发现所有运行中的反应堆系统的热量损失均高达90％，因此为了抑制两种操作，而无需预热的流化气体，并且在测试了部分混合物后切割所有电加热的操作。对于两种测试，都获得了良好的结果。对于后者，关闭加热器后可以持续2个小时以上的操作，并将运行的热量损失降低至72％。