炼化企业中水回用工业应用效果跟踪分析与研究

An Analysis of Results of Wastewater Reclamation and Reuse in Refining Companies

对于炼化企业而言,炼油污水回用存在稳定性差、水质复杂以及容易造成腐蚀、结垢、微生物繁殖等问题。中国石油锦西石化分公司将炼油污水回用二期超滤产水回用于循环水系统,并对中水回用后的循环水水质控制指标和循环水系统运行效果进行了分析。回用水与新水的水质指标数据对比显示,回用水作为循环水补水的工艺方案是可行的,但总碱度持续偏低,有造成循环水系统腐蚀的风险。通过调节新水与回用水比例,循环水总碱度基本达到了100mg/L以上,有效降低了循环水系统的腐蚀风险。小型动态实验结果表明,适当投加缓蚀剂可以较好地控制循环水的腐蚀趋势。循环水现场监测分析结果显示,微生物控制总体上效果较好;现场监测换热器的试管腐蚀率和试管黏附速率均在控制指标范围内;在线探针监测腐蚀率与现场监测换热器试管监测腐蚀率均在控制指标范围内。

Recycling of refinery sewage is often accompanied with problems such as poor stability, complex water quality conditions and ease of corrosion,scaling and microbe propagation.Petro China Jinxi Petrochemical Company recycled refinery sewage for use in the circulating water system and analyzed the indicators of quality of the circulating water recycled from sewage as well as the operation of the circulating water system.A comparison between the indicators of quality of recycled water and fresh water shows that the plan of us-ing recycled water to replenish circulating water is feasible although total alkalinity is consistently low,which may result in corrosion of the circulating water system.After the proportions of fresh water and recycled wa-ter,the total alkalinity of circulating water basically reached 100mg/L or higher,meaning that corrosion risk has dropped considerably.The results of small dynamic experiments show that an appropriate use of corrosion inhibitor can effectively control the corrosion trend for circulating water.Field monitoring and analysis of cir-culating water shows that microbe control is overall effective.The test tube corrosion rate and test tube adhe-sion rate for heat exchangers,monitored in the field,are all within the range of specifications and the corrosion rate monitored with online probes and the test tube corrosion rate for heat exchangers that is monitored in the field are also within the range of specifications.