PTA装置溶剂脱水塔D1—601腐蚀与控制

Corrosion in D1-601 Solvent Dehydration Column in PTA Plant

针对PTA装置溶剂脱水塔D1-601的腐蚀状况,通过镀钯实践及研究温度与Br^-质量浓度对腐蚀的影响,对该设备的腐蚀机理及镀钯后的耐蚀机理进行了分析。经研究表明:在还原性醋酸介质中,镀钯可以有效地提高不锈钢的耐腐蚀性能,不锈钢表面镀钯可以解决其在PTA装置中含Br^-醋酸环境下的腐蚀问题;工艺参数的控制直接影响着设备的耐腐蚀性能,在能满足醋酸溶剂回收的前提下,应尽量降低操作温度并严格控制Br^-含量;镀钯与控制工艺参数相结合是解决D1—601及PTA装置中其它类似环境下不锈钢腐蚀的有效途径。

The corrosion in PTA plant was becoming increasingly acute. To find a cost - effective corrosion control method, Palladium- plating and the effect of temperature and Br - concentration on corrosion were investigated, and the corrosion mechanisms and anti - corrosion mechanisms after application of Palladium - plating were analyzed. The investigation has shown that Palladium - plating on stainless steel surface can effectively improve its resistance to corrosion in acetic acid medium and solve the corrosion problem in Br - environment of PTA plant. The control of process parameters has a direct impact on the corrosion - resistance performance of equipment and a good unit operation is critical for extending the operating cycle of equipment. In operation of the D1 -601 solvent dehydration column, the operating temperature should be possibly lowered and Br- should be controlled. The combination of Palladium - plating with proper control of process parameters provides an effective means to minimize the corrosion of stainless steel in D1 - 601 solvent dehydration colmnn and other equipment with similar environment in PTA plant.