The Research Of Green Recovery Technology Of Gasoline And Diesel Alkaline Residue

Alkaline residue which has high concentration and toxicity was a special organic waste water with deep color, smell and strong corrosion. Alkaline residue was one of the main pollution sources of oil refineries. The process of treating with alkaline redidue also has some problems now, such as incomplete treatment of wastewater and complex process. The technology of electrodialysis and diffusion dialysis was widely used as green recovery in last years. For green treatment of alkaline residue, electrodialysis and diffusion dialysis were used for recycling NaOH from alkaline residue in the study.The selection of ion exchange membrane would decide the recovery effect when the alkaline residue was recovered by electrodialysis. In the study, we compared the recovery effect of AK cation membrane, Shanghua cation membrane, Shanghua anion membrane and Tianwei anion membrane. Among those choosed membranes, performance parameters of AK cation membrane were the best, so the recovery effect by using AK cation membrane was better than the others. The recovery rate of NaOH can be more than 70%. The application was limited, because the AK cation membrane was very expensive. When the electrodialysis was used to reclaim NaOH from alkaline residue, the higher the voltage was, the higher the recovery rate was, and the shorter the time of recovery was. But if the current was too high, it would shorten the life of the electrode and the ion exchange membrane. The voltage 25V～30V was appropriate through thinking about the effect of reclaiming and the durability of the electrode and the ion exchange. The recovery rate of NaOH was increased by improving flow and increasing pressure. But the enduring ability of the device should be considered, when selected the flow and pressure.When diffusion dialysis was used for recovery of alkaline residue, the ion differential concentration was the main driving force of diffusion. All of the factors which can change the differential concentration would influence the recovery effect. Because the ion migration depends on differential concentration diffusion, the maximum recovery rate of NaOH was 50%. Alkaline residue and water circularly flowed in the device of forced-diffusion, so the recovery effect of forced-diffusion was better than the recovery effect of free-diffusion. The recovery effect of electrodialysis was better than the recovery effect of diffusion dialysis, but diffusion dialysis was low energy consumption and simple device. When alkaline residue contained low organic compounds, the diffusion dialysis to recover NaOH should be selected. When alkaline residue contained high organic compounds, recycling NaOH by electrodialysis could get better recovery effect in the short time than the diffusion dialysis.The nature of raw alkaline residue decided the recovery effect no matter which methods were used to recover alkaline residue. The alkaline residue of high NaOH content and low organic compounds content was easier recovered and could get high quality recovered alkaline. In the study, the alkali resistance and organic resistance of ion exchange membrane were the main factors that influenced the recovery effect. Only to develop new ion exchange membrane which used in the recovery of alkaline residue, the recovery of alkaline residue by electrodialysis and diffusion dialysis can be widely used.