基于利润核算的常减压装置中段取热优化

常减压装置是炼化企业最重要的组成部分之一,不仅其用能情况关乎全套工艺流程的总能耗,而且其侧线产品收率和品质对下游工艺具有举足轻重的影响。目前常减压装置取热比例对净利润影响的研究相对较少,本文借助Aspen流程模拟软件及其相关组件对塔设备和换热网络进行模拟,在其他工艺参数优化的基础上,分析了常压塔和减压塔的高温位中段取热比例对侧线产品收率、换热器维护及折旧费用、循环水费用以及燃料油费用的影响。结果表明高温位中段取热比例与换热器维护和折旧费用呈正相关,而与轻油拔出率、循环水费用以及燃料油费用呈负相关。通过以上分析结果确定了将常二中取热比例从33.1%提高到38.1%,减三中取热比例从40%降低到35.4%,可以使得炼化企业的净利润进一步提高1.46亿元/年,为企业进一步提高生产效益提供了理论基础。     

原油常减压蒸馏装置的流程模拟及参数优化

根据某原油常减压蒸馏装置的工艺流程,采用Aspen Plus软件对装置的初馏塔、常压塔和减压塔进行流程模拟计算,获得了各产品的温度、流量等关键参数及减压塔侧线产品的馏程曲线,并与实际数据对比,二者吻合良好. 分析了塔板温度和气液相流量沿塔板的分布,运用灵敏度分析工具对相关参数进行优化,优化后常压塔柴油收率可增加0.22 t/h,常压塔热负荷降低6.3%,减压塔轻油收率上升0.18%,减压塔热负荷降低11.2%.     

提高装置工业燃料油初馏点和闪点的研究

某石化公司常压装置原油加工能力为150万t/a，采用“初馏+常压塔”工艺技术。在装置实际生产过程中，初馏塔侧线油和常压侧线油作为工业燃料外送至罐区，因初馏塔侧线油含有较多的石脑油组分，此举不仅造成石脑油浪费，且也使工业燃料油组分偏轻，初馏点和闪点偏低，不利于罐区油品的安全储存。针对该情况，通过生产参数调整优化、流程改造等措施实施，不仅提高了工业燃料油初馏点和闪点，同时也提高了装置石脑油收率。     

350万t/a常减压装置扩能及轻质化改造

为适应轻质化原油及装置扩能的需要,对某石化公司350万t/a常减压装置进行改造设计,通过建立全流程的模拟和换热网络计算,分析装置主要存在的瓶颈,通过优化换热网络、调整各中段取热、增加塔顶冷却、改造初馏塔和部分常压塔塔板等措施将设计处理能力提高到420万t/a,同时适应加工轻质原油需要,提高换热终温,降低装置能耗。     

原油蒸馏过程的模拟与分析

采用ASPENPLUS软件的PetroFRAC模块对原油蒸馏过程进行模拟,模拟得到的总物料平衡、操作条件和产品质量等结果与工厂生产装置数据较为一致。通过灵敏度分析发现初馏塔和常压塔塔顶馏出量、常压塔塔底蒸汽量和侧线汽提蒸汽量这几个显著影响拔出率的因素,为原油蒸馏操作优化方案的制定奠定基础。     

低碳经济下常压塔蒸汽汽提优化

蒸汽汽提作为调节蒸馏塔油气分压的重要手段,目前更多地考虑到对侧线产品收率和品质的影响。通过Aspen Plus流程模拟软件对某炼化企业3#常减压装置进行全流程模拟,并对常压塔蒸汽汽提进行碳排放和成本两方面分析,结果表明:当常压塔汽提蒸汽量从5.5 t/h提高到5.9 t/h时增加了约14.6万/年的经济效益的同时碳排放量仅增加40.0吨/年。该结果不仅为企业进行相关优化提供理论指导,而且奠定了未来炼化企业在保证经济效益的同时限制碳排放在合理范围内的优化原则。     

初馏塔提压操作的适用性和经济性分析

利用Aspen Plus流程模拟软件建立初馏塔提压操作模型,结合模型分析了初馏塔提压操作对常减压装置能耗、液化气收益和操作经济性的影响。同时,详细阐述了初馏塔提压对原料和操作的适用性。结果表明,初馏塔提压可以提高整个常减压装置的经济性,对于原油加工量为800万t/a的常减压装置,每年能增加收益5 000万元左右。     

常减压装置三塔组焊安装施工方法

以某石化公司千万吨常减压装置为例,简述三塔(常压塔、减压塔、初馏塔)的组焊施工方法。     

利用Petro-SIM优化常减压装置汽提蒸汽量

利用英国KBC公司开发的Petro-SIM软件对常减压蒸馏装置操作进行模拟。通过对模型操作参数的调整,分别模拟初馏塔汽提蒸汽量和常压塔汽提蒸汽量对常减压蒸馏装置侧线产品质量、轻油收率和装置能耗的影响,以选择合适的汽提蒸汽量,达到优化汽提蒸汽量、指导装置节能的目的。     

降低常压蒸馏塔渣油350℃馏出量的控制措施

针对中石化西安石化分公司常压蒸馏装置渣油350℃馏出量长期较高的问题,通过提高产品拔出量、提高常压塔底汽提蒸汽流量、提高加热炉出口温度、合理调节常压塔二中回流量等措施使常压蒸馏塔渣油350℃馏出量明显降低:抽出常一线产品后渣油流量降低了9 t/h,渣油350℃馏出量下降了3%;对石脑油、常三线质量靠指标上限控制,渣油350℃馏出量平均下降约1%;在常三线95%质量指标和加热炉出口温度不变的条件下,提高常压塔底汽提蒸汽流量,常压塔底渣油350℃馏出量也会降低;在加工量相同时,适当调节常压塔二中回流量,常压渣油350℃馏出量也会降低。通过以上调整措施,常压蒸馏装置2013渣油350℃馏出量较2012年平均下降2.82%,减少催化加工费用约为389.10万元,综合收益为761.82万元。     

3~#常减压蒸馏装置换热网络的操作优化

利用英国Process Integration Ltd.(PIL)公司最新的原油精馏系统优化技术,对茂名分公司3#常减压蒸馏装置换热网络进行建模及优化操作。结果表明,通过优化常压塔中段取热分配,将常顶冷回流量降到几乎为零,原油换热后温度提高了7℃,实现了能量回收最大化。     

常减压蒸馏与汽柴油加氢精制工艺组合增产航空煤油

中国石油辽阳石化分公司炼油厂为增产航空煤油,采用5.50 Mt/a常减压蒸馏与2.00 Mt/a汽柴油加氢精制工艺组合,通过调整两套装置工艺流程和主要设备的操作参数,于2015年3月5日成功生产出满足3号喷气燃料质量指标的航空煤油,为企业带来了可观的经济效益。主要的操作参数为:常压塔常二线抽出温度205℃、常二线抽出量60 t/h、加氢精制反应器入口温度320℃、出口温度335℃、高分压力6.0 MPa、循环氢流量72 000 Nm3/h、氢油体积比327。     

A novel process integrating vacuum distillation with atmospheric chlorination reaction for flexible production of tetrachloroethane and pentachloroethane

In this paper,we developed a novel process integrating vacuum distillation with atmospheric chlorination reaction (VD-ACR) to realize the flexible production of tetrachloroethane (TeCA) and pentachloroethane (PCA)from 1,2-dichloroethane (DCA).During the simulation,the distillation column and reactors were operated for separation and chlorination respectively under variable pressures and temperatures.It is interesting to note that VD-ACR processes producing pure TeCA or PCA can exhibit the similar configuration parameters after optimization,which enables the flexible production of TeCA and PCA with different molar ratios via changing operating parameters.The molar ratio of TeCA/PCA can be fine-tuned within the range of 0.9∶0.1-0.1∶0.9 through adjusting the amount of chlorine pumped into side reactors,giving rise to the increase of the heat duty of reboiler by five times.A pilot-scale experiment was then operated based-upon this VD-ACR process and the result matched well with the simulation.Therefore,the VD-ACR model presented in this study will be beneficial for the industrial-scale flexible production of TeCA and PCA from DCA.     

常减压蒸馏装置减压深拔技术设计

依据常减压蒸馏装置减压深拔现状及研究动态,结合8.0 Mt/a常减压蒸馏装置设计实例,分析了为实现减压深拔目标减压系统所采用的工艺技术,包括较高的加热炉出口温度、减压炉防结焦、减压塔塔顶高真空度和全塔低压降、微湿式带汽提操作、减压塔塔底防结焦等工艺,并重点讨论了过气化油流程设置对减压深拔的影响。     

原油常减压蒸馏塔的流程模拟

常减压蒸馏装置是炼油加工的第一道工序,它的运行状况对后续装置乃至全厂都有着重要影响。针对初馏塔、常压蒸馏塔和减压蒸馏塔的稳态流程模拟,选取适合的蒸馏塔中段循环设定变量和减压塔模拟方法,最终流程模拟结果与实际工艺参数相似度极高,说明常减压蒸馏塔的流程模拟能够如实体现实际工艺状态,可以作为指导工艺生产、操作优化的有效方法。     

Modeling and simulation of a nitric acid recovery process

A nitric acid recovery process using composite distillation columns was modeled and simulated. The composite distillation columns consist of a multistage vacuum tower and an atmospheric pressure tower half of which consists of packed bed. The vacuum tower and the atmospheric pressure tower were modeled by using equilibrium stage method and non-equilibrium stage method respectively. The required thermodynamic properties for nitric acid solution were obtained from correlations based on experimental data. Results of simulations showed good agreement with actual plant data. From the results of simulations it was found that the upper half of the atmospheric pressure column and the vacuum column, consisting of plate column, can be modeled using equilibrium model, but the lower half of the atmospheric pressure column, which are packed parts, can be modeled effectively using non-equilibrium model. The non-equilibrium model developed in the present study showed good agreement with actual operaton data.     

基于EGO算法的常压塔能量优化

常减压装置能量消耗约占炼厂总用能的25%～30%,在保证产品产量与质量的条件下,优化常减压蒸馏塔操作条件,可有效降低能耗.为了避免随机优化算法对常压塔机理模型进行操作优化时,存在计算资源消耗大、效率低的问题,文中采用基于代理模型的全局优化方法优化常压塔的余热回收过程,在优化迭代过程中用Kriging代理模型来代替耗时的精确模型评估.实验表明模型调用次数相较于粒子群优化算法减少了90%,优化时间减少了85%,实现了能量优化并且保证了侧线产品之间的分离精度.     

Soft-sensing modeling and intelligent optimal control strategy for distillation yield rate of atmospheric distillation oil refining process

It is a challenge to conserve energy for the large-scale petrochemical enterprises due to complex production process and energy diversification. As critical energy consumption equipment of atmospheric distillation oil refining process, the atmospheric distillation column is paid more attention to save energy. In this paper, the optimal problem of energy utilization efficiency of the atmospheric distillation column is solved by defining a new energy efficiency indicator — the distillation yield rate of unit energy consumption from the perspective of material flow and energy flow, and a soft-sensing model for this new energy efficiency indicator with respect to the multiple working conditions and intelligent optimizing control strategy are suggested for both increasing distillation yield and decreasing energy consumption in oil refining process. It is found that the energy utilization efficiency level of the atmospheric distillation column depends closely on the typical working conditions of the oil refining process, which result by changing the outlet temperature, the overhead temperature, and the bottom liquid level of the atmospheric pressure tower. The fuzzy C-means algorithm is used to classify the typical operation conditions of atmospheric distillation in oil refining process. Furthermore, the LSSVM method optimized with the improved particle swarm optimization is used to model the distillation rate of unit energy consumption. Then online optimization of oil refining process is realized by optimizing the outlet temperature, the overhead temperature with IPSO again. Simulation comparative analyses are made by empirical data to verify the effectiveness of the proposed solution.     

加工进口劣质原油常减压腐蚀原因分析及防护措施

原油蒸馏塔腐蚀是造成炼油厂常减压装置非计划停工和发生事故的重要原因之一,结合潍坊弘润石化助剂有限公司1.2Mt/a和2.5Mt/a两套蒸馏装置实际运行情况,分析了加工劣质进口原油后常减压塔腐蚀的机理,提出了减小常减压塔腐蚀的措施,延长了开车周期。