Net Present Value Analysis of Modular Chemical Production Plants

Modular plants consist of modules that autonomously operate parts of the plant. These modules are technically and organizationally limited areas of the plant that fulfill defined tasks. Starting with these modules, companies can create capacity either by equaling up modules from general structures or by numbering up equipment. Here, the economics of a modular chemical plant are compared with those of a traditional large‐scale plant by investigating the net present value. The modular plant presents a more efficient concept for fast growing products or products with volatile demands. This is because the market impact during operation is more important than the preceding influence of the investment. In those cases, the effects of flexibility surpass the effects of scale.     

Modular Microstructured Reactors for Pilot‐ and Production Scale Chemistry

In recent years, two strategies in continuous‐flow plant technology attracted strengthened interest: First, the use of microstructured devices as a new tool for process intensification and second, the modularity of interchangeable devices which leads to more flexibility. To take advantage of both, these approaches were combined within the EU‐project CoPIRIDE. Microstructured modular reactors were fabricated by novel manufacturing techniques. Different types of such reactors were characterized in terms of reaction engineering. Residence time distribution, heat transfer performance, pressure drop, and liquid‐liquid mixing performance were investigated.     

Production and purification of glutamic acid: A critical review towards process intensification

Amidst growing environmental awareness and stringent discharge regulations, chemical and allied process industries are now desperately seeking replacement of the conventional, polluting processes by clean and green processes. In this context, production and purification of amino acids like l-glutamic acid assumes significance. Concerned conventional process involves several steps like fermentation, centrifugation, carbon adsorption, evaporation, crystallization, ion-exchange and so on to get glutamic acid in desired concentration and purification. Despite its tremendous potential for large scale use in a wide variety of applications, cost-effective production of high purity glutamic acid has remained a challenge for decades, mainly due to several downstream processing steps and the associated cost factors. With emergence of tailor-made membranes and modules, possibility of using membranes in downstream purification of glutamic acid appears imminent with expectation of a turnaround in amino acid manufacturing industry. The present study through a brief yet comprehensive review of the very critical aspects of glutamic acid production and purification, attempts to direct research efforts towards process intensification encompassing the concepts of green processing, compact and flexible design with promise of more economically attractive production with better quality.     

Calibration-Free Chemical Process and Quality Control Units as Enablers for Modular Production

Modular chemical production is a tangible translation of the digital transformation of the process industry for specialty chemicals. In particular, it enables the speeding-up of process development and, thus, a quicker time to market by flexibly connecting and orchestrating standardized physical modules and bringing them to life (i.e., parameterizing them) with digitally accumulated process knowledge. We focus on the specific challenges of chemical process and quality control, which in its current form is not well suited for modular production and provide possible approaches and examples of the change towards direct analytical methods, analytical model transfer or machine-supported processes.     

A Modular Approach for Surrogate Modeling of Flowsheets

Flowsheet simulation, an important building block in chemical process development and design, generally requires the solution of a nonlinear system of equations. Such a simulation can fail if either no solution exists for the chosen specifications or if the initial values for the solver are chosen unfavorably. In this work, to overcome such convergence failures, AI-based surrogate models are trained for unit operations of a flowsheet and then interconnected. For a pressure swing distillation with recycle, it is shown that such an interconnection of surrogate models yields more accurate results compared to a surrogate model for the whole flowsheet at once, and that adequate starting points for the flowsheet simulation can be obtained from the interconnected surrogates.     

Evaluation of a two-temperature control structure for a two-reactant/two-product type of reactive distillation column

Several different control structures have been proposed for reactive distillation columns. The appropriate control structure depends on the flowsheet and on the type of reactions occurring in the column. If two reactants are involved and if it is desirable to operate the process without any excess of reactant, it is necessary to manage the fresh feed streams so that the stoichiometry is exactly balanced. A composition analyzer that measures an internal composition in the column is often required. However, if two products are produced, it is possible to avoid the use of an analyzer by using two temperatures in the column to adjust the two feed streams. This type of structure was proposed by Roat et al. [Roat, S., Downs. J., Vogel, E., Doss, J., 1986. Integration of rigorous dynamic modeling and control system synthesis for distillation columns. In: Chemical Process Control—CPC III. Elsevier, Amsterdam.] for the ideal reaction A+B↔C+D in one of the earliest papers dealing with reactive distillation control.The purpose of this paper is to explore the effectiveness of this two-temperature control structure for various column designs (number of reactive stages) to quantify the impact of design on controllability. We also discuss the issues of the selection of the trays whose temperatures are to be controlled and the tuning of the two interacting temperature controllers. Disturbances in production rate and fresh feed compositions are made to examine the rangeability of this control structure. Both an ideal reaction system and the methyl acetate system are studied. One of the main conclusions is that the locations of the temperature control trays should be made such that the two temperature controllers both have direct action (an increase in temperature increases feed), which requires negative openloop process gains for both loops.     

Production Rate‐Dependent Key Performance Indicators for a Systematic Design of Biochemical Downstream Processes

Key performance indicators have become a common tool in bioprocess development, as they allow an objective and independent rating and ranking of process alternatives screened. A disadvantage of all key performance indicators developed so far is their strong focus on costs, which makes them neglect the influence of the production rate on the profit of the process. But, since both production costs and production rate have an equally strong impact, both should be considered when decisions have to be made. Therefore, two new key performance indicators are introduced in this work, one for batch and one for continuous processing. They combine product yield, purity performance, variable manufacturing costs, and production rate to one objective. Thereby, misguided trade‐offs between these four individual measures can be replaced by one key performance indicator. This ensures a systematic development of biochemical downstream processes.     

Highly Efficient Enzymatic Synthesis of 2-Monoacylglycerides and Structured Lipids and their Production on a Technical Scale

We report here a two-step process for the high-yield enzymatic synthesis of 2-monoacylglycerides (2-MAG) of saturated as well as unsaturated fatty acids with different chain lengths. The process consists of two steps: first the unselective esterification of fatty acids and glycerol leading to a triacylglyceride followed by an sn1,3-selective alcoholysis reaction yielding 2-monoacylglycerides. Remarkably, both steps can be catalyzed by lipase B from Candida antarctica (CalB). The whole process including esterification and alcoholysis was scaled up in a miniplant to a total volume of 10 l. With this volume, a two-step process catalyzed by CalB for the synthesis of 1,3-oleoyl-2-palmitoylglycerol (OPO) using tripalmitate as starting material was established. On a laboratory scale, we obtained gram quantities of the synthesized 2-monoacylglycerides of polyunsaturated fatty acids such as arachidonic-, docosahexaenoic- and eicosapentaenoic acids and up to 96.4% of the theoretically possible yield with 95% purity. On a technical scale (>100 g of product, >5 l of reaction volume), 97% yield was reached in the esterification and 73% in the alcoholysis and a new promising process for the enzymatic synthesis of OPO was established.     

A Modular Process Modeling Tool for the Analysis of Energy Use and Cost in the Pulp and Paper Industry

A novel process modeling tool to facilitate the study of how various process changes in the paper dryer section affect the mill-wide energy system has been developed. A model library with steady-state block models describing paper dryers, heat recovery equipment, and auxiliary systems on component level have been developed using the software Extend. Process models are then created from these block models using graphical programming. In this article, the characteristics of the developed tool are described and a case study where the tool is shown to be useful for analyzing the energy performance of a hybrid dryer section is presented.     

A Modular Process Modeling Tool for the Analysis of Energy Use and Cost in the Pulp and Paper Industry

A novel process modeling tool to facilitate the study of how various process changes in the paper dryer section affect the mill-wide energy system has been developed. A model library with steady-state block models describing paper dryers, heat recovery equipment, and auxiliary systems on component level have been developed using the software Extend. Process models are then created from these block models using graphical programming. In this article, the characteristics of the developed tool are described and a case study where the tool is shown to be useful for analyzing the energy performance of a hybrid dryer section is presented.     

乙烯生产技术及应用

简要介绍了当前世界乙烯工业的生产技术,说明了当前乙烯工业的主要专利技术公司的特点及其应用情况,主要介绍了我国乙烯工业技术的发展概况,并针对我国乙烯工业存在的问题,提出了若干建议.     

Process systems engineering: From Solvay to modern bio- and nanotechnology.: A history of development, successes and prospects for the future

The term Process Systems Engineering (PSE) is relatively recent. It was coined about 50 years ago at the outset of the modern era of computer-aided engineering. However, the engineering of processing systems is almost as old as the beginning of the chemical industry, around the first half of the 19th century. Initially, the practice of PSE was qualitative and informal, but as time went on it was formalized in progressively increasing degrees. Today, it is solidly founded on engineering sciences and an array of systems-theoretical methodologies and computer-aided tools. This paper is not a review of the theoretical and methodological contributions by various researchers in the area of PSE. Its primary objective is to provide an overview of the history of PSE, i.e. its origin and evolution; a brief illustration of its tremendous impact in the development of modern chemical industry; its state at the turn of the 21st century; and an outline of the role it can play in addressing the societal problems that we face today such as; securing sustainable production of energy, chemicals and materials for the human wellbeing, alternative energy sources, and improving the quality of life and of our living environment. PSE has expanded significantly beyond its original scope, the continuous and batch chemical processes and their associated process engineering problems. Today, PSE activities encompass the creative design, operation, and control of: biological systems (prokaryotic and eukaryotic cells); complex networks of chemical reactions; free or guided self-assembly processes; micro- and nano-scale processes; and systems that integrate engineered processes with processes driven by humans, legal and regulatory institutions. Through its emphasis on synthesis problems, PSE provides the dialectic complement to the analytical bent of chemical engineering science, thus establishing the healthy tension between synthesis and analysis, the foundation of any thriving discipline. As a consequence, throughout this paper PSE emerges as the foundational underpinning of modern chemical engineering; the one that ensures the discipline's cohesiveness in the years to come.     

Modeling of Ethylene Glycol Production from Glucose in a Semi-Continuous Reactor

A numerical study describes the catalytic conversion of glucose into ethylene glycol (EG) in a semi-batch reactor. This analysis couples a set of power law models (homogeneous reactions) and Langmuir-Hinshelwood-Hougen-Watson (LHHW) equations (hydrogenations). For this purpose, the kinetic parameters of the LHHW expressions are estimated for the reaction conditions. Then, the kinetic model evaluates the influence of the H₂ pressure and the catalyst concentrations on the selectivity. The results indicate that the EG yield is increased by setting the temperature and the H₂ pressure. In this manner, the process reduces the hexitols and methane production and increases the EG yield. The originality of the work is based on the influence of the H₂ pressure and the catalyst concentrations in the model.     

Design of a Microstructured System for Homogenization of Dairy Products with High Fat Content

High pressure homogenization of dairy products is today state of the art but limited by the fat content (max 17 vol.‐%). This article describes the development of a novel simultaneous homogenization and mixing (SHM) valve which allows homogenization of dairy products with a fat content of up to 42 vol.‐%. The challenging task of homogenizing dairy products with high fat content is to stabilize disrupted fat droplets especially against extensive aggregation. Aggregation and coalescence rates could be significantly reduced by a new microstructured valve allowing the emulsifier‐containing phase to be injected directly into the zone of droplet disruption.     

Overview of Surrogate Modeling in Chemical Process Engineering

The ability to accurately model and simulate chemical processes has been paramount to the growing success and efficiency in process design and operation. These improvements usually come with increasing complexity of the underlying models leading to substantial computational effort in their use. It may also occur that the structure of the model is sometimes unknown making optimization and study difficult. To circumvent these issues, mathematically simpler models, commonly known as surrogate models, have been designed and used to successfully replace these complex, underlying models with much success. This technique has seen increasing use within the chemical process engineering field and this article summarizes some popular surrogates and their recent use in this area.     

喷雾干燥法制取VAE粉体工艺技术

针对四川维尼纶厂2000t／a VAE粉体中试项目的喷雾干燥过程工艺过程及重要设备进行核算,确保工艺设计达最大优化,工艺设备布局合理,对今后大型VAE粉体装置工艺设计提供基础设计数据。     

35kt/a含硫废液制酸装置设计简介

国内现有石化、化工、钢铁、煤气化等行业在各自生产主要目标产品的过程中,同时会副产大量的富含硫酸盐类的废液,含硫废液直接大量排放会严重污染环境,危害人体健康。简要介绍了含硫废液制硫酸的技术,阐述了其回收原理、工艺流程及主要设备等。     

Syngas Production Process Development and Economic Evaluation for Gas‐to‐Liquid Applications

The range of syngas composition produced by autothermal reforming of natural gas makes it suitable and in compliance with the gas‐to‐liquid technology for subsequent conversion to synthetic crude oil. A modified and improvised design for this reforming technique is proposed in which oxygen consumption is reduced as compared to the conventional process. Simulative optimization helps in optimal designing of the new process subject to a set of constraints applied to both the processes for uniform and homogeneous comparison. Aspen HYSYS is used for simulation and optimization of the process and the economics are evaluated by an Aspen Process Economic Analyzer.