Selection And Optimization Of Ethyene Feedstock

The steam thermal cracking technology of American Kellogg Company was adopted. Hydrocarbon types of feedstock were determined by using PIONA special analyzer, the properties of cracking feedstock were analyzed and evaluated, then the cracking feedstock and cracking process for ethylene were optimized. The cracking experimental results showed that Lanzhou Petrochemical Company had increased the ethylene yield by 1.52 % and gain the economic profit of RMB 42 million yuan per year by choosing Kusi (库西) naphtha as the liquid phase feedstock cracking for ethylene. Normal butane was a light cracking feedstock of high quality and suitable for high-temperature cracking. Isobutane contains too much isoparaffin and it is unsuitable for cracking. The volumes of isoparaffin and olefin content being too high, cracking C₄ hydrocarbon mixture alone was inadvisable. However, blending a certain proportion of C₄ hydrocarbon mixture into Kusi (库西) naphtha for cocracking is feasible. The cracking experiments were made by adding C₄ hydrocarbon mixture to naphtha by 5%, 8%, and 13.6% respectively, the suitable amount of C₄ hydrocarbon mixture for blending should be controlled under 10%.The on-line chromatograph could solve the entire analysis problem of gas phase products samples including H₂ , guaranteeing the analytic accuracy of the cracking gas products. The analytic method was improved for the special light samples, and Extend determine range of the instrument.To provide accurate data for the development, selection and evaluation process of C₄ de-acetylene hydrogenation catalysts, the contents of butadiene and alkyne among C₄ hydrocarbon mixture were mensurated by using gas chromatography HP5890A, which could be widely applied in the process of research, development and production. Compared to once used method with the packed columns, the analytic method offered superior advantages of simpleness, rapidness, accuracy, reliableness, satisfied separation efficiency and high reproductability.The experimental results of the extension of coke cleaning period for industrial Furnace showed that the coking of naphtha cracking mainly concentrated in the beginning of feeding; the total coking would reduce by 30% with 200 ppm dimethyl-disulfur was added at this stage, adding dimethyl-disulfur had less impact on the distribution of the product naphtha cracking; the results show the temperature influenced the coking rate of naphtha cracking significantly.