Rigorous algorithmic targeting methods for hydrogen networks—Part II: Systems with one hydrogen purification unit

A new systematic targeting methodology has been developed to minimize the use of hydrogen utility in hydrogen networks that also feature purification of hydrogen. Sufficient and necessary conditions of optimality have been proved to extend the pinch based approach to this nonlinear problem. The proposed targeting procedure involves two steps: identification of purifier location and calculation of minimum hydrogen consumption. Examples from the literature are discussed.     

硫化氢的提纯及应用

概括了介绍了硫化氢的应用及提纯工艺。     

膜分离-变压吸附联合工艺生产燃料电池氢气

将膜分离技术和变压吸附两种气体分离与净化技术相结合．充分发挥了两种工艺模式的优点．使得装置整体性能指标在稳定性、产品品质和氧气回收率上均有优异的表现,最终使得单位原料气的获利大幅挺高。另外,联合工艺具有广泛的适应性,能够灵活采用各种运行模式以适用于各种不同的气源。     

High throughput screening techniques in downstream processing: Preparation, characterization and optimization of aqueous two-phase systems

Merging aqueous two-phase systems (ATPS) with high throughput screening techniques is a promising approach which will certainly lead to a more frequent use of ATPS both in industry and in research. Despite the diverse possible applications of polymer-polymer or polymer-salt based extraction systems for biotechnological downstream processes the use of these systems has so far been limited. This is mostly due to the poor predictability and the large number of parameters influencing the partitioning result. Especially the large number of possible parameter combinations makes robotic high throughput screening an interesting alternative to manual experiments. Methods using the robotic pipetting station Tecan Freedom Evo 200 for the development of ATPS processes are described in this paper. Characteristic values such as tie lines, binodal curve and volumetric measurement are essential for the characterization of this kind of systems and can successfully be determined by the robotic system. Most important, the measurement of protein concentrations, partition coefficients and yields could also be automated and parallelized offering the possibility to design ATPS processes while screening a broad range of parameters with a high sample throughput.     

Industrial application of an extended fully thermally coupled distillation column to BTX separation in a naphtha reforming plant

Aromatic compounds are yielded from naphtha reforming in a petrochemical plant, and the products are separated with binary distillation columns for benzene, toluene, xylene and heavy components in sequence. In this study, the first three columns of the fractionation process in the naphtha reforming unit are replaced with an extended fully thermally coupled distillation column (EFTCDC) also known as the extended Petlyuk column. An industrial-sized application of the EFTCDC is examined to compare the performance of the column with a conventional system. From a structural design giving the optimum structure of the column, a practical column structure is derived and used in the HYSYS simulation to find the optimal operation condition for a given set of product specifications. The EFTCDC gives an energy saving of 9.7% over a conventional three-column process. In addition, it is proved that the design procedure is good for an industrial process of 18 components.     

PROCESS OPTIMIZATION IN ULTRAFILTRATION: FLUX-TIME CONSIDERATIONS IN THE PURIFICATION OF MACROMOLECULES

An empirical model was developed to describe the flux of a complex milk protein suspension under ultrafiltration and diafiltration conditions. Flux decreased during ultrafiltration, but increased during diafiltration as the permeable solids concentration decreased. The “gel” model based on film theory was modified to describe the flux in terms of both retained and permeable solutes. The least-time processing strategy for a given end product concentration was also modelled and identified for this protein system. In general, ultrafiltration followed by diafiltration is best if protein purification is the goal.     

乙炔气体湿法净化及改造

针对50万米~3/年乙炔站清净工序的生产性质及要求,采用了以次氯酸钠液湿法净化乙炔气的方法,并阐述了清净工序的改造设计。净化后的乙炔气中硫化氢、磷化氢含量总和小于10ppm,净化效果好,安全可靠,成本低,效益好,值得乙炔站推广。     

化工设备设计部门网络系统的建立与实施

针对目前化工设备设计人员使用单机工作,给设计带来诸多不便,笔者根据自己的实际建网经验,提出了适合化工设备设计部门使用的廉价局域网,并给出了具体建立方法与实施步骤。     

Application of a thermally coupled distillation column with separated main columns to gas concentration process

A modified fully thermally coupled distillation column (FTCDC) for operability improvement is utilized in a gas concentration process. The column consists of a prefractionator and two separated main columns having high distillation efficiency and flexible control structure. The operability of the proposed column is evaluated by examining the open-loop dynamic responses of step input variations with the HYSYS simulation. The simulation result indicates that the modified system can give better control than the original FTCDC. The energy saving and reduction of construction cost are discussed, and the ease of vapor flow manipulation and the elimination of a compressor in the vapor transfer are also evaluated as possible improvements.     

Exergy analysis in ProSimPlus® simulation software: A focus on exergy efficiency evaluation

On industrial sites, the promotion of best practices to enable an efficient utilization of energy has emerged as one of the major point of focus. Among the different approaches existing to improve industrial processes, the exergy analysis, although limited to the academic world, has been shown to be a powerful tool for improving energy efficiency of thermal and chemical systems. The purpose of this paper is then to present the use of the ProSimPlus^® modelling and simulation environment as an exergy analysis computer-aided tool. Expressions implemented in the simulator for computing exergies in its various forms are presented. The adopted approach for calculating exergy efficiency in a systematic way is also exposed; it combines the fuel-product concepts to the transit exergy concept. ProsimPlus^® exergy module's capabilities are illustrated through the example of an ammonia production plant.     

清洁燃料升级中炼厂氢气系统优化运行与探讨

介绍了长庆石化公司清洁燃料升级进程中,通过建设制氢装置和扩大重整副产氢能力,采取有效的技术和管理手段,围绕氢气系统运行过程中的突出问题和难点,优化氢气系统运行,达到了以最低氢气成本生产清洁燃料和提高企业经济效益,特别是提升企业竞争力的目的。     

Model-based risk assessment on dynamic control of twin-column continuous capture under feedstock variations

Dynamic control is essential to guarantee the stable performance of continuous chromatography.AutoMAb dynamic control strategy has been developed to ensure a consistent protein load in twin-column CaptureSMB continuous capture by integrating the UV signal of breakthrough.In this study,the process risk of CaptureSMB continuous capture under AutoMAb control towards the feedstock var-iations was assessed by a mechanistic model developed by us.The effects of target protein and impurities under the variation range of±10 mAU·min-1 on load amount,protein loss,process productivity,and resin capacity utilization were investigated.The results showed that the CaptureSMB process could be successfully controlled by AutoMAb towards increased or slightly decreased concentration of feedstock.However,the load process would be out of control with drastically decreased target protein or impu-rities,and the decreased impurities would lead to protein loss.It was found that AutoMAb control would cause 44.7％non-operational areas and 18.3％protein loss areas in the variation range of±10 mAU·min-1.To improve the stability of the CaptureSMB process,a modified AutoMAb control that would stop the load procedure when the absolute value of the integral area reached the preset value,was proposed to reduce the risk of protein loss and the non-operational area.     

A variational approach to the control of electrochemical hydrogen reactions

Optimal control problems for the hydrogen evolution reaction (HER) system are solved for different cost objectives and admissible control strategies. The solution for the set-point-change process is given in analytical terms when the admissible controls are continuous functions of time. For piecewise-continuous controls the problem admits a solution as a feedback law. In both cases the cost functional penalizes the electrochemical power spent in the process, which translates into a Lagrangian more involved than classical quadratic. The theoretical framework remains into the Calculus of Variations for infinite-horizon problems. The Hamiltonian control formalism is adapted to treat the problem when the final time is bounded.     

Design of a fully thermally coupled distillation column for hexane process using a semi-rigorous model

An industrial scale hexane process is designed for the implementation of a fully thermally coupled distillation column (FTCDC). A semi-rigorous material balance and Peng-Robinson equilibrium relation are utilized in the structural design. The operational design is conducted with a commercial design program, the HYSYS. The design outcome of the structural design indicates it to be comparable with the practical system of a conventional two-column arrangement in field operation, which shows the effectiveness of the design procedure implemented here. The procedure is good for the system of many components found from actual field applications. In addition, an investigation of the energy requirement of the FTCDC and a conventional system shows that an energy saving of 34.1% is available with the FTCDC.     

Design of a fully thermally coupled distillation column based on dynamic simulations

A dynamic simulation of a fully thermally coupled distillation column is conducted for the design of a possible operation scheme, and its performance is examined with an example process of butanol isomer ternary system. The outcome of the dynamic simulation indicates that the column can be operated by using a 3 × 3 control structure. The structure consists of three controlled variables of the compositions of overhead, bottom and side products and three manipulated variables of the flow rates of reflux and steam and liquid split ratio between a main column and a prefractionator. This paper was presented at The 5th International Symposium on Separation Technology-Korea and Japan held at Seoul between August 19 and 21, 1999.