Optimal Operation On Wet Air-Oxidizing Device For Treating Refinery Alkaline Residue

Refinery alkaline residue is a kind of spent alkali liquorproduced in refining industry of petroleum. Alkaline residue is darkand stink, containing many contaminants, such as sulphide, volatilizephenol and naphthenic acid, different density neutral oil, anddissociate alkali as well. So alkaline residue is one of the mainpollution sources of the refinery plant. Wet air oxidation is one kindof treatments on refinery alkaline residue, with high efficiency, lowsecondary pollution, and high oxidizing-speed. Years ago, several setsof caustic-sludge wet air oxidizing device, whose dealing capabilityare all above 2m~3/h, have been applied successfully into domesticpetrochemical filed. Recent years, with the development ofhydrofining, with which the alkali-wash refining can be substituted,the amount of alkaline residue produced in refinery plant isdecreasing, so the scale of device for treating alkaline residuebecomes smaller and smaller. In June of 2003, Chang Ling Branch Company of petrochemicalindustry joint-stock company of China invested 65 million RMB, andbuilt up the first domestic set of wet air-oxidizing device for treatingalkaline residue, with a 1m~3/h dealing capability. However, a lot ofproblems on the system were presented at the initial operation stage,such as scale forming-clogging, results unable to reach the designingrequirement, and so on. Therefore, the device is unable to run steadilyon a long cycle. Under this situation, a group leading by the authorhas been established to tackle the principle problems, workingtogether with designing unit of the device. After analyzing and studying the origin cause of scale formation,the principle problems were found out, and correspondingimprovement measures were carried out, the problem of unable to runon a long cycle because of system stock was well solved. Majorinfluencing factors were discussed on this basis, and main optimumoperation parameters of the device were chose by debuggingrepeatedly through the scene. The result showed that the removalefficiency of Sulphide was steadily above 99.9% by adoptingoptimum operation parameters, and result reaches designingrequirement, thus establishing a good foundation for popularizationand application of the wet air-oxidizing device.