分子筛催化汽油烷基化降苯技术研究进展

随着世界各国环保意识的提高,对汽油中苯含量的要求也越来越严苛。汽油降苯技术主要包括加氢饱和、精馏分离、醚化以及烷基化等技术,其中烷基化技术无论从提高辛烷值还是增加汽油收率方面都具有明显优势。本文综述了目前应用最为广泛的甲醇和轻烃作为烷基化试剂的工艺路线和反应机理,对典型分子筛ZSM-5、MCM-22以及Beta的结构及特点、催化烷基化特性进行了具体分析。并指出:甲醇作为烷基化试剂相比于碳数较高的轻烃,需要更高的反应温度,但对汽油的馏程影响更小。轻烃作为烷基化试剂随着碳数的增加活化温度相应降低,但对汽油的馏程影响较大,且低温条件下促进烯烃的聚合引起分子筛的失活。3种分子筛的应用目前很难兼顾苯转化率、汽油馏程以及能耗,孔道大小适中分子筛的开发、复合分子筛和多级孔分子筛的制备有望成为解决该问题的重要方式。

基于成本核算的加氢精制分离过程分析

加氢精制是炼化企业的重要组成部分,主要包括汽油加氢、航煤加氢以及柴油加氢精制单元。本文借助Aspen流程模拟软件及其相关组件,对比不同产品在一定生产规模条件下采用冷高分和热高分工艺下的成本核算,研究结果可为企业进行相关分离过程设计提供理论基础。

Rheological Properties of Waxy Crude at a Low Temperature in the Presence of Pour Point Depressants

Pour point depressants （PPD） are used to improve the theology of waxy crude. The affect of various factors on the theological properties, and the thermal characteristics of waxy crude treated by PPD have been investigated. The conclusions are as follows： PPD can reduce the pour point and abnormal point of waxy crude, broaden the temperature range of Newtonian fluid of waxy crude, and lower greatly the viscosity of non-Newtonian fluid of waxy crude. The influence of reheating and high-rate shear on the effect of PPD mainly depends on their temperature. When the reheating temperature is more than the abnormal point of crude by 10℃, the reheating process has little effect on the modification effect of PPD. However, when the reheating temperature is below the abnormal point of crude, the reheating process will reduce the modification effect of PPD. When temperature is above the abnormal point of crude, the high-rate shear has little effect on the modification effect of PPD. At a temperature range where a lot of wax is precipitating, high-rate shear will greatly reduce the modification effect of PPD.

SWOT-AHP hybrid model for vehicle lubricants from CNPCLC,China

In recent years, owing to the strong increase in demand for lubricants, China is ranked second in the global lubricant market. With the rapid development of China＇s automobile industry, there is an increasing demand for vehicle lubricants and an increasing requirement for higher quality lubricants. While the demands for vehicle lubricants are increasing year by year in China, the quality grade of vehicle lubricant will be improved by leaps and bounds, and the high standard lubricant for automobile will be directly brought in line with international practice. At present, the market share of most high-end vehicle lubricant has been occupied by foreign lubricant brands. So for China National Petroleum Corporation Lubricant Company （CNPCLC）, the urgent issue is that strategies must be made to respond to the stern challenges and to occupy more market share. In this paper, by using the analytic hierarchy process （AHP） technique that has the advantage of combining quantitative with qualitative analysis, a SWOT-AHP model for CNPCLC vehicle lubricants is developed, presenting a good tool for studying the competitive factors domestic and overseas for vehicle lubricants. Finally a strategic plan for CNPCLC vehicle lubricants is suggested.

Analysis and calculation model of energy consumption and product yields of delayed coking units

Delayed coking is an important process consumption and light oil yield are important factors used to convert heavy oils to light products. Energy for evaluating the delayed coking process. This paper analyzes the energy consumption and product yields of delayed coking units in China. The average energy consumption shows a decreasing trend in recent years. The energy consumption of different refineries varies greatly, with the average value of the highest energy consumption approximately twice that of the lowest energy consumption. The factors affecting both energy consumption and product yields were analyzed, and correlation models of energy consumption and product yields were established using a quadratic polynomial. The model coefficients were calculated through least square regression of collected industrial data of delayed coking units. Both models showed good calculation accuracy. The average absolute error of the energy consumption model was approximately 85 MJ/t, and that of the product yield model ranged from 1 wt% to 2.3 wt%. The model prediction showed that a large annual processing capacity and high load rate will result in a reduction in energy consumption.

不同负荷工况对污泥桨叶干化工程运行效果的影响

利用桨叶干化工艺对城市脱水污泥进行处理,依托某污泥干化项目开展不同负荷工况干化运行效果的影响研究,考察了含水率、蒸汽耗量、循环载气和性质变化,并进行系统运行经济性分析。结果表明:桨叶干化是一种适于污泥处理的技术,出泥效果稳定,含水率低于30%且可调节,蒸发速率在10~20 kg H_(2)O/(m^(2)·h),具有自清洁功能能有效防止污泥粘结;蒸汽消耗系数为1.045~1.397,理论设计值可设定为1.4;循环载气量约为蒸发水量的0.78~1.27 kg/(kg H_(2)O·h);在干燥机内部干化过程中循环载气量适当增大可增加空气与污泥直接的对流换热系数,提高干化速率和减少蒸汽耗量。蒸汽成本占直接运行成本的89%,在项目实际运行过程中,在满足目标处理含水率的条件下,可根据实际项目情况通过降低运行负荷比例和增加循环载气量降低蒸汽耗量,通过设备运行参数精细化管理降低运行成本,检修时应关注干燥机中前段设备磨损和粘壁情况,以减少因污泥粘膜造成的换热损失。

AEA在常减压装置换热网络优化中的应用分析

常减压装置换热网络优化作为降低公用工程使用量的重要方式而被学者们广泛关注。炼化企业现有常减压装置因设备及空间限制,进行换热网络调整的空间较为有限。以某炼化企业3#常减压装置为例,借助Aspen Energy Analysis模块,确定了最优夹点温差10℃下的夹点温度为247.9℃/237.9℃。在不改变原换热流程的基础上,以年度总成本为优化目标,通过改变换热器的热负荷和物流分流比,不仅降低了10.6 GJ/h热工程和10.6 GJ/h冷工程的使用量,而且将跨夹点换热量从42.7 GJ/h降低到32.1 GJ/h。新增设备投资106.2万美元,效益为48.6万美元/年,投资回收期约为2.2年,具有良好的经济效益,为企业进行相关设备优化提供理论基础。

Selection of Sinopec Lubricating Oil Producing Bases by Using the AHP Model

The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process （AHP） model for selecting lubricating-oil producing bases was developed. By using this model, nine lubricating oil producing companies under Sinopec were comprehensively evaluated. The evaluation result showed that the Maoming Lubricating Oil Company （Guangdong province）, Jingmen Lubricating Oil Company （Hubei province） and Changcheng Lube Oil Company （Beijing） are top three choices, and should be developed preferentially for the development of Sinopec producing bases of lubricating oil in the future. The conclusions provide the theoretical basis for selecting lubricating oil producing bases for decision makers.

Investigation of scale inhibition mechanisms based on the effect of scale inhibitor on calcium carbonate crystal forms

To probe the scale inhibition mechanisms,calcium carbonate scale occurring before and after the ad- dition of scale inhibitors was collected.The results from scale SEM confirm that,without scale inhibitor, calcium carbonate scale shows rhombohedron and hexagon,which are the characteristic feathers of calcite.After addition of inhibitors,morphology of scale is changed,and the more efficient the scale inhibitor is,the more greatly the morphology is modified.To elucidate the scale constitute,they were further analyzed by FT-IR,XRD.Besides calcite,vaterite and aragonite occur in calcium carbonate scale after addition of inhibitors,and the higher scale inhibition efficiency is,the more vaterite presents in scale.It can be concluded that the alteration of morphology is ascribed to the change of crystal form. There are three stages in the crystallizing process including occurrence and disappearing of unstable phase,occurrence and disappearing of metastable phase,development of stable phase.Without scale inhibitors,metastable phases usually transform into stable phase,thus the main constitute of formed scale is calcite.When scale inhibitors are added,both formation and transformation of metastable phases are inhibited,which results in the occurrence of aragonite and vaterite.From the fact that more vaterite presents in scale with a more efficient scale inhibitor added,we can see that the function of scale inhibitor is realized mainly by controlling the crystallizing process at the second stage.