新型热耦合反应精馏应用于乙酸甲酯水解的研究

A different pressure thermally coupled reactive distillation column(DPT-RD) for the hydrolysis of methyl acetate(Me Ac) is developed, and its design and optimization procedures are investigated. The sensitivity analysis is carried out to minimize the energy consumption, which is associated with the total annual cost(TAC). The influence of the proposed DPTRD scheme on energy consumption and economic efficiency are evaluated in comparison with the conventional reactive distillation column(CRD). Both the DPT-RD and CRD are simulated with the Aspen Plus?, and it can be observed that for the DPT-RD the energy consumption and the TAC are reduced, and the thermodynamic efficiency is increased as compared with the CRD process.     

Heat Exchanger Network Retrofit for Optimization of Crude Distillation Unit Using Pinch Analysis

Crude distillation unit(CDU)is regarded as the main energy consumer in the entire refinery process.In this paper,the process simulation software and the energy management software are used to simulate the flowsheet and analyze the energy consumption,respectively.Stream data obtained from an existing CDU are applicable in the pinch analysis.To reduce the amount of cross-pinch heat transfer,three approaches of resequencing,repiping,and adding heat exchangers are adopted.Compared with the existing CDU,the results demonstrate that the inlet temperature of the furnace can be increased by 25.4℃,the amount of hot and cold utilities can be reduced by 15.1%and 19.6%,respectively.The economic evaluation indicates that the operating cost is saved by 8×106$/a,and the payback period is about 9 months.     

Synthesis and Design of Distillation Columns for Wide-Boiling Binary Mixtures with Vapor Recompression Heat Pumps

The vapor recompression heat pump(VRHP) distillation technology offers significant improvements in energy efficiency for distillation systems with small temperature differences between the top and bottom of the column. However, the separation of wide-boiling binary mixtures leads to substantial temperature differences between the top and bottom of the column. This limits the applicability of conventional VRHP due to high capital costs and strict performance requirements of the compressor. To ove...     

Heat Exchanger Network Retrofit of Diesel Hydrotreating Unit Using Pinch Analysis

Diesel hydrotreating unit(DHT) is an integral part of the refinery, and its energy-saving optimization is of great significance to the enterprise. In this paper, process simulation software and energy management software are used to simulate the flowsheet and analyze the energy consumption, respectively. Stream data obtained from an existing DHT are applied in the pinch analysis for retrofitting the heat exchanger network(HEN) to achieve maximum energy utilization by using pinch analysis. Since DHT is constrained by pressure, the pressure factor is considered in the process of retrofitting. The results show that the amount of cross-pinch heat transfer is reduced, the inlet temperature of the furnace is increased by 55 ℃, and the amount of hot and cold utilities can be reduced by 70.25% and 50.16%, respectively. The economic evaluation indicates that the operating cost is saved by 4.39×10~6 $/a, and the payback period is about 2 months.     

An alternative treatment process for upgrade of petroleum refinery wastewater using electrocoagulation

An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and produce larger amounts of sludge. The effect of the operation parameters, such as current density, initial pH, anode material, anode dissolution, energy consumption and electrolysis time, on treatment efficiency was investigated. The experimental results showed that the effluent can be effectively treated under optimal conditions. Fourier transform infrared （FTIR） analysis of the effluent, and scanning electron microscopy （SEM） coupled with energy dispersive analysis of X-rays （EDAX） of the sludge produced, revealed that the unwanted pollutants can be eliminated. The electrocoagulation treatment process was assessed by using the removal efficiency of chemical oxygen demand （COD）, total suspended solids （TSS）, and the general physicochemical characteristics of wastewater, and the results showed that the electrocoagulation is an efficient process for recycling of petroleum wastewater; it is faster and provides better quality of treated water than the conventional methods.     

Striving for an Energy and Resources Saving Refinery with Harmonious Development

The operating circumstances of refinery industry in China in 2005 were referred to in this paper, along with the processes for development of petrochemical industry aimed at regionalization, concentrated disposition of enterprises and construction of industrial bases. The pressure faced currently by the oil refining industry in terms of resources avalibility and environmental regulations was analyzed. The key elements associated with the refining industry restructuring to economize on all kinds of resources were discussed and presented. It is stated that the key for building an energy and materials saving oil refining industry should rely on the adoption of advanced process and engineering technology, adjustment of refinery configuration, improving the energy and resources utilization efficiency, deep processing of crude oils, optimizing all kinds of resources, reducing effluents by saving water, as well as boosting the integration of oil refining with chemical production, concentrated disposition and realization of large scale of process units.     

热集成水网络优化设计的最新进展

It is well known that the process industry is an energy-intense and water-consuming industry and is the main source of industrial water consumption and energy in China. Energy integration and mass integration are important approaches to achieve energy saving and emission reduction in the process industry. Generally, the methods can be classified into two groups: conceptual design methods and mathematical programming methods. The former includes mainly graphical methods based on pinch technology that is operated easily. A feasible solution can be quickly obtained. Conceptual design methods are sequential in nature including targeting and design two steps. The latter is based on superstructure optimization and corresponding algorithm is adopted to solve the model. The trade-offs and connections among the entire network can be established and explored. Multiple factors can be considered and optimized simultaneously by mathematical programming methods. This paper describes the synthesis of heat integrated water allocation networks (HIWAN) based on both conceptual design methods and mathematical programming methods systematically. In addition, the characteristics and shortcomings of the existing research methods are summarized, and the future research direction is prospected.     

Study on Regeneration of MDEA Solution Using Membrane Distillation

Treating acid gases contained in natural gas by MDEA is used widely. But the efficiency of regeneration of the MDEA solution limited the development of this technology. An optimal temperature is necessary for regeneration of the MDEA solution using membrane distillation. The experiment results showed that the regeneration rate of MDEA rose with an increasing temperature. But the rate increased slowly after the regeneration temperature arrived at a certain value. This study can confirm that regeneration of the MDEA solution using membrane distillation is feasible. This technology provides more advantages as compared to conventional regeneration process.     

Post-riser Regeneration Technology in FCC Unit

In our present work, a post-riser regeneration technology (PRRT) for fluid catalytic cracking (FCC) units was developed to deal with increasingly heavier feedstock and hereby the larger amount of coke deposited on the catalyst particles during reaction. This technology can make full use of the advantages of riser regenerator, such as high coke-burning efficiency and low residual carbon, and at the same time overcome its disadvantages, such as difficulty in starting combustion. The average particles concentration on the cross section of the system was studied on a large scale cold model experimental set-up. Also a necessary software was developed by combining the hydrodynamics research results in our work with the coke-burning kinetics model and the heat and mass transfer model developed by previous researchers. The simulation results showed that the PRRT could increase regeneration capability by 16.28%-26.24% over the conventional turbulent fluidized bed regenerator under the similar operation conditions, and that the residual carbon could be kept below 0.1 wt %.     

Butylene Concentrating Technology Developed by Yantai University with Independent Intellectual Property Right

The Haiji Chloroalkali Chemical Company, Ltd. in Inner Mongolia has created the technology for clean production of PVC/vinyl chloride with independent intellectual property rights. The clean production process for bulk polymerization of vinyl chloride independently developed by this company is characterized by simple process flow diagram, low consumption of additives, low energy cost, absence of wastewater discharge, good product quality and good product processability. According to relevant experts of China Chloroalkali Industry Society, compared to the existing production equipment in China this technology has apparentadvantage in terms of energy conservation,     

基于异丁烯提纯反应精馏的热泵流程模拟及分析

基于异丁烯提纯反应精馏的特点，设计了塔顶蒸汽压缩式的热泵节能流程。利用Aspen Plus软件对全流程进行模拟，并提出了针对部分冷凝流程的热泵精馏模拟策略。从火用分析和技术经济的角度，全面对其进行能耗和经济性分析评价。案例研究结果表明：采用热泵节能技术的反应精馏过程，当压缩比为1.6时，能耗及总费用最低；且与常规反应精馏过程相比，采用热泵节能技术后单位产品能耗降低约87.5%，热力学效率提高32.7百分点，年操作费用下降64.4%，热泵投资回收期为1.5年。     

变压精馏分离丙酸甲酯-甲醇的节能设计

基于丙酸甲酯-甲醇二元体系的压力敏感特性,以最小年总费用(TAC)作为经济评价指标,对变压精馏分离工艺进行了模拟与优化,并在常规工艺基础上进行了改造,以实现节能的目的。结果表明:常规分离工艺高压进料时,高压塔塔板数为41、回流比为1.5和进料位置为第33块板以及低压塔塔板数为39、回流比为2.0和进料位置为第17块板时TAC最低,为593.00万元/年。将热集成技术应用于常规工艺中,优化后的分离工艺均能实现物系的高效分离。相比于常规变压精馏,部分热集成变压精馏与全热集成变压精馏分别可以节约44.57%与41.94%的能耗,同时可以节约23.84%与32.59%的TAC,主要原因是热量集成使得蒸汽费用与换热器费用降低。优化后的两种工艺分离效果显著,且能耗与TAC均较低,可为工业设计提供理论参考。     

合成乙酸丁酯的热泵技术的分隔壁反应精馏流程模拟与优化

在合成乙酸丁酯的工艺中，将热泵技术用于其分隔壁反应精馏流程。针对这种塔顶、塔釜流股温差较大的体系，基于热泵技术提出了3种不同的分隔壁反应精馏流程，分别为：塔底换热的热泵分隔壁反应精馏流程、带中间换热的热泵分隔壁反应精馏流程和带预热器及中间换热的热泵分隔壁反应精馏流程。优化分析这3种精馏流程的能耗和年总费用(TAC)，并与常规分隔壁反应精馏流程进行对比。结果表明，热泵技术的应用使分隔壁反应精馏流程的能耗和费用都显著地降低；带预热器和中间换热的热泵分隔壁反应精馏流程是该合成工艺中反应精馏流程的优化选择；与常规分隔壁反应精馏流程相比，在回收期为8 a时带预热器和中间换热的热泵分隔壁反应精馏流程可以使能耗、CO2排放和年总费用分别降低35.18%、71.53%和35.35%。     

基于离子液体的乙腈-乙醇-水共沸体系节能分离

乙腈生产过程中产生的乙腈-乙醇-水物系,由于在常压下产生了3种二元共沸物和1种三元共沸物,采取常规精馏无法对物系进行有效分离,因此基于COSMO-SAC理论对具有应用潜力的4种离子液体进行筛选,选定1,3-二甲基咪唑磷酸二甲酯([DMIM][DMP])作为分离乙腈-乙醇-水物系的适宜萃取剂,并利用σ-谱图对离子液体与该物系的作用机理进行分析;采用Aspen Plus软件建立了基于离子液体分离乙腈-乙醇-水物系的萃取精馏流程。以年度总费用(TAC)最低为优化目标,并将CO₂排放成本计入目标函数中进行流程优化。在此基础上,为了更有效节能,进一步设计优化了热泵精馏萃取分离流程。最终热泵精馏流程TAC比常规流程降低16.82%,CO₂排放费用减少了23.35%。     

基于中间换热器-吸收式热泵精馏节能系统的优化

为提升精馏环节的能源利用效率,基于高效回收换热器余热和梯级用能的理念,提出了设置中间换热器与吸收式热泵相结合的精馏节能系统;以某石化企业180 kt/a气体精馏“三塔”(脱丙烷塔、脱乙烷塔、丙烯精制塔)系统中的脱丙烷塔为研究对象,采用Aspen Plus建立数学模型,对中间换热-吸收式热泵精馏节能系统的中间再沸器、中间冷凝器以及热泵的操作参数进行优化,并对“三塔”精馏流程的节能效果进行分析。结果表明,采用中间换热-吸收式热泵精馏节能系统可将脱丙烷塔的蒸汽消耗量降低25%;对于完整“三塔”精馏流程,蒸汽消耗量可降低38.8%,循环冷却水用量节约42.5%,新增利润约530.8万元/a,项目静态投资的回收期为3 a。     

中间再沸式热泵反应精馏生产乙酸异丁酯的设计与控制

基于传统反应精馏(CRD)合成乙酸异丁酯(IBAC)塔顶塔底温差较大的特点,提出中间再沸式热泵反应精馏(IR-HPRD-1)以及带预热器的中间再沸式热泵反应精馏(IR-HPRD-2)流程。采用Aspen软件对其进行优化,得到最优工艺操作参数。在稳态模拟基础上,采用奇异值分解法(SVD)找出温度灵敏板,对IR-HPRD-2流程设计了可行的控制方案。结果表明：与CRD工艺相比,IR-HPRD-1和IR-HPRD-2的年总能耗(TUC)分别降低44.33%和47.55%,年总费用(TAC)分别降低16.92%和19.13%,IR-HPRD-2在节能与降低TAC方面更优于IR-HPRD-1;在±20%进料流率与5%进料组分扰动下,该可行性控制方案能在短时间内有效控制产品质量。     

分壁塔替代两塔分离芳烃流程改造的研究

分壁精馏塔以其特有的结构和分离方法,在能耗和投资上较常规多塔串联分离多组分混合物有明显优势。本研究以芳烃抽提装置中精馏单元分离苯、甲苯、二甲苯的常规两塔分离序列为研究对象,提出和对比了3种分壁精馏塔的就地改造方案。建立了常规两塔分离及3种改造方案的稳态严格精馏模型,分析和对比了3种改造方案的节能效果。结果表明,3种分壁精馏塔的改造方案的节能效果分别为11.5%,32.4%,34.0%,其中将原两塔流程中苯塔改为分壁精馏塔的精馏段、甲苯塔改为预分馏段和提馏段的方案更易在工程与实施。     

偏三甲苯多效热集成分离工艺的模拟研究

采用化工流程模拟软件Aspen Plus、选取PR-BM热力学模型对从C9芳烃分离精制偏三甲苯的工艺进行模拟研究。通过对不同工艺流程的比较和分析,发现在精馏分离流程中,采用双效热集成技术可以明显降低精馏分离工艺的能耗,与传统精馏工艺流程相比,其节能率可以达到64.79%;偏三甲苯产品的纯度达到98.51%,收率为90.54%。     

气体分馏装置的节能优化

随着节能工作进一步开展,各种新节能设备和技术日趋完善。化工过程系统也陆续提出解决炼油等行业生产过程中如何更有效地回收能量提高能量利用率的问题,这一问题的解决对于生产中的节能降耗具有重要意义。通过对多套气体分馏装置的研究,利用过程能量集成技术对其换热网络进行节能优化,提出了热泵精馏的工艺。该工艺可靠,节能效果显著,且可行,并具有十分重要的意义。