焦化装置冷切焦水系统运行分析及优化改造

Analysis and Optimization of Performance of Coke Cooling and Cutting Water Systems in DCU

九江石化1.0Mt/a延迟焦化装置冷、切焦水系统采用密闭处理技术,进行除油、除焦粉,并经冷却后循环使用。分析认为,该系统存在安全、环保运行隐患,水中含油、含焦多,油品损失大,新鲜水耗量大。为此,在原有工艺流程优化操作基础上,通过在冷焦水储罐增设氮气气封,放水线增设排放线和过滤器,沉淀池增设隔油设施,循环水场外排污水回用,富余的切焦水补充冷焦水系统,以及放空冷却塔含油污水回收方式改进等工艺流程技术优化改造,解决了冷切焦水系统长周期安全稳定运行的隐患,实现了该系统新鲜水消耗量为零的目标,每年可节约新鲜水8×104t,缓解了外排污水的环保治理压力,促进了装置节水减排工作。优化后的污油回收方式可实现年回收污油1200t,既改善了冷焦水的水质,又减少了油品损失。针对该系统存在的其他问题,提出进一步完善改进的技术建议。

The coke cooling and cutting water systems of Sinopec Jiujiang Company＇s 1.0Mt/a delayed coking unit use closed-type processing technology for removing oil and coke powder,which are then reused after being cooled off.Analysis shows that the unit has some safety and environmental hazards.In addition,as the water contains high contents of oil and coke ,loss of oil products is large and consumption of fresh water is very high.To resolve these problems,this article proposes a series of technical methods to optimize the process of the coke cooling and cutting water systems of the unit based on optimized operations of the existing process.These methods include adding nitrogen gas seal for the coke cooling water storage tank,adding a discharge line and filter for the water drain line ,adding oil trap facilities for the sedimentation tank,recycling the sewage from the circulating water system,replenishing the coke cooling water system with surplus coke cutting water and improving the way of recycling the oily sewage from the vent cooling tower.These methods could help remove the hazards threatening the long-term stable operation of the coke cooling and cutting water systems and reduce the fresh water consumption of the systems to zero.This could save 8×10^4t of fresh water annually and in the meantime alleviates the environmental pressure from sewage discharge,thus contributing to the water saving and discharge reduction efforts of the company.The optimized effluent oil recovery method could recover 1200t of oil annually and would also help improve the quality of water and reduce oil product loss.The article also puts forth some technical proposals to tackle other problems with the systems.