重芳烃参与柴油调合实例分析

Case Study of Introducing Heavy Aromatics in Blending Diesel Fuel

大连石化220×104t/a连续重整装置生产的重整汽油主要以C9以上组分的重芳烃为主,终馏点平均在244℃以上,增加了参与汽油调合的难度,但经分析,重芳烃参与柴油调合的控制点则为闪点。大连石化轻质油品调合主要是管道自动化调合,各组分油品经管道静态混合器后进入成品罐,然后再经过泵循环或者机械搅拌使之充分混合、密度均匀,其调合传质机理主要是涡漩扩散起作用,最终由分子扩散达到完全均匀混合。对重芳烃参与柴油调合的比例数据做初步核算,并据此探讨重芳烃参与柴油调合的可行性与工艺管线设计等问题,项目于2009年7月初施工完毕,投资约30万元。通过实例跟踪和经验公式计算,在大连石化目前柴油生产现状的情况下,重芳烃参与柴油调合的体积分数控制在6%以内,能够保证调合后的成品柴油满足质量指标要求。

C9 or above heavy aromatics were the dominant components in the reformed gasoline produced by PetroChina Dalian Petrochemical Company＇s 220×10^4t/a continuous reformed unit.The end points averages above 244℃.This increased the difficulty of blending these components into gasoline.Analysis showed that the control point for blending heavy aromatics in diesel fuel is the flash point.Light oil products produced by Dalian Petrochemical Company are mainly blended in pipelines automatically.Different components of oil prod- ucts enter oil product tanks after passing through static pipeline mixers and will be further mixed thoroughly to ensure homogeneity of density by means of pump circulation or mechanical mixing.The main blending and mass transfer mechanism involved here is vortex diffusion effect.As a result of molecular diffusion,the blended fuel becomes homogeneous.Technicians estimated the dose of heavy aromatics used in blending diesel fuel and based on their findings ,discussed the feasibility of introducing heavy aromatics in blending diesel fuel as well as process pipeline designs.Construction of the project was completed in July 2009.Investment in it was about 300,000 yuan.Based on case studies and empirical equation calculations,these technicians concluded that the volume fraction for blending heavy aromatics in diesel fuel should not exceed 6% in order to ensure the diesel fuel blended meets quality requirements.