聚丙烯粉料异味产生的原因分析及对策

Cause analysis and countermeasures for the odour diffused from polypropylene powders

分析了聚丙烯(PP)粉料异味的产生原因,并提出了相应对策。结果表明,PP发生降解,PP粉料中夹带烃类化合物、硫化物等杂质是导致PP粉料产生异味的原因。通过采取提高闪蒸罐顶部气体温度,提高汽蒸蒸汽流量,增加汽蒸罐洗涤塔和干燥器洗涤塔的水洗频次等措施改善汽蒸及干燥效果,降低了PP粉料中烃类化合物及挥发分的含量;及时更换丙烯精制单元的脱硫剂,以去除丙烯中的一些硫化物杂质;严格控制PP粉料包装时的料位和温度,尽量缩短存放周期。

The causes of odour diffused from polypropylene （PP） powders were analyzed and the corresponding countermeasures were put forward.The results showed that the odour was attributed to the degradation of PP and the impurities of hydrocarbons and sulfides contained in PP powders.The efficiency of steaming and the drying operations was improved by increasing the temperature at the top of flash tank and the steam flow in steamer as well as the the washing cycles of scrubber in steamer and dryer systems,thus decreasing hydrocarbons and volatile contents in PP powders.Desulfurizing agent in propylene refining unit was replaced in time in order to effectively remove the sulfides in propylene.The material level of PP powder tank and the temperature of PP powders which needed to be strictly controlled and the storage period should be shortened as far as possible while PP powders were packed.