Chemical Process Design

Chapter 1: Process Background & Selection
Chapter 2: Site Location
Chapter 3: Mass Balance
Chapter 4: Energy Balance
Chapter 5: Process Simulation
Chapter 6: Environmental and Waste Management
Chapter 7: Process Integration
Chapter 8: Process Control & Instrumentation
Chapter 9: Design of Major Equipment (Chemical & Mechanical)
Chapter 10: Economic Analysis
Chapter 11: Plant Safety & Layout

The conceptual design, modeling, and optimization of a MeOH-to-H 2 processor by an integration of a multi-tube annular membrane methanol reformer (MTAMMR) and the preheating system are presented. The annular membrane methanol reformer (AMMR) is a packed-bed reactor consisting of two concentric cylinders and its surface is covered with the Pd-Cu membranes. When the methanol steam reforming and the preferential oxidation reactions are carried out in the outer and the inner tubes, respectively, the counter-current axial flow in the annular gap can ensure the thermally self-sustaining operation. Under sufficient consideration of the effect of heat integration, three plate-fin heat ex-changers (PFHEs) are taken into account in the preheating system. Through a series of optimization algorithms for maximizing the H 2 permeation rate of each AMMR and minimizing the total energy demand of the preheating system, respectively, the optimal operating conditions and specifications of MeOH-to-H 2 processor are obtained. Finally, it is successfully found that the perfect weight of the optimized MeOH-to-H 2 processor is close to the H 2 tank weight for 2016 Toyota Mirai vehicle if the PFHEs use titanium material.

Levulinic acid (LA), which is one of the top twelve value-added chemicals from biomass feedstock, has been recognized in a large number of applications. Nevertheless, its capability on an industrial scale has been limited by the high-cost of the raw materials and the lack of detailed process design. This paper reports the simulation, detailed design and optimization of an industrial process recovering LA from biomass, a renewable and inexpensive feedstock. The aqueous feed mixture from the acidic hydrolysis of biomass was fed to the separation process to recover LA as the main product, along with furfural and formic acid as valuable byproducts. Furfural was then used as an extracting solvent, resulting a significant decrease in total cost. Detailed analysis was conducted to assess the feasibility of the separation method. The purification process was intensified by applying an innovative top dividing wall column with a decanter configuration (TDWC-D). The response surface methodology (RSM), which allows the interactions between variables to be identified and quantified, was used to optimize the TDWC-D structure. The predictions by the RSM showed satisfactory agreement with the rigorous simulation results. The results showed that the innovative TDWC-D configuration could save up 16.4% and 20.6% of the overall energy requirements and total annual cost, respectively, compared to the conventional sequence.

Although used as an essential utility extensively in process industries especially in oil and gas plants, design methodology for hot oil system is not well documented in the open literature. To meet this gap, a design guideline for this process system is described systematically. Sizing basis of all the equipment in the system is presented with illustrative calculations. Additionally essential considerations required for development of the Process & Instrument diagram, control system along with system protection philosophy and basis for selection of pressure safety valves are outlined in the article.

Ethanolamines are raw materials widely used in industry. Carbon dioxide and hydrogen sulfide absorption and the production of materials such as paint, rubber, adhesive, detergent, soap are the areas where ethanolamines are frequently used. With the formation of new industrial areas, the demand for ethanolamine is increasing every year.
Our design project aimed to produce mono-, di-, tri-ethanolamine of high purity and quality. In aqueous environment, ethanolamines are obtained by the serial reactions carried out by feeding ammonia and ethylene oxide into the plug flow reactor. This process runs on a continuous model. Compared with other alternatives, the selected process has more sensitivity to the environment. Production planning Turkey's industrial structure has been expected to establish a complex system. For this reason, it was decided to establish the facility in İzmir, Aliağa Industrial Zone. We take into account when determining the quality of our process is the most important factor in Turkey's foreign trade deficit ethanolamine field. Accordingly, our annual production capacity has been determined as 4440 tons.
Mass, energy and utility requirements values and some calculations were made using Chemcad® simulation software. The process flow chart and block diagram were drawn using Microsoft Visio 2013, and the process control charts of the equipment were drawn using Draw.io. Capcost 2012 was used in the economic analysis. Other calculations were made by manually.

As the range of feedstocks, process technologies and products expand, biorefineries will become increasingly complex manufacturing systems. This book presents process modelling and integration, and whole system life cycle analysis tools for the synthesis, design, operation and sustainable development of biorefinery and chemical processes.

A hybrid reactive distillation system with high selectivity pervaporation was examined to produce butyl acetate and methanol via transesterification of methyl acetate with butanol. High selectivity pervaporation was combined with reactive distillation to eliminate a hitherto required column for the separation of a methanol and methyl acetate azeotrope. The polyamide-6 membrane was used for this purpose because of its high selectivity for methanol while also allowing sufficient permeate flux. The high purity methyl acetate recovered in the retentate stream leads to high conversion in the reactive distillation column, which enhances the energy savings (up to 71%) of this process. The feasibility of the proposed hybrid processes and several alternative designs were evaluated by rigorous simulation and optimization using the Aspen Plus software package. The effects of several designs and operating variables were also investigated for the proposed design. The high potential of the hybrid reactive distillation and pervaporation system for butyl acetate production is very promising; it may not only reduce the total annual costs relative to conventional systems but may also provide an attractive strategy to address problems associated with methanol and methyl acetate azeotropes in the effluent generated in the polyvinyl alcohol industry.

This paper presents a novel hybrid process combining thermally coupled reactive distillation with membrane-based pervaporation for enhanced production of n-butyl acetate. A conventional reactive distillation process was used as the base case and first optimized for the transesterification of methyl acetate with n-butanol to produce n-butyl acetate. It was observed that methyl acetate recovered in the recycle stream significantly affects the con-version in the reactive distillation column and overall energy efficiency of the whole process. The existing and proposed configurations were evaluated and optimized by simulation in Aspen Plus. The integration of thermally coupled reactive distillation and pervaporation improved the energy efficiency of the reactive distillation process by preventing remixing effect in the reactive distillation column and eliminating the azeotropic nature of the methanol and methyl acetate in the recycle stream, respectively. Finally, integration of the thermally coupled reactive distillation with a commercial pervaporation membrane was explored to take synergistic advantage of the thermally coupled reactive distillation and pervaporation hybrid configuration. As a result, the proposed hybrid design showed remark-ably improved energy efficiency and economics. The total reboiler duty and total annual cost reduced to 63 and 43%, respectively, compared to those of the base case.

Distillation columns are widely used in many chemical process industries, especially in oil and gas processing. Accidents in the distillation columns have resulted in enormous loss of human lives and assets. Inadequate design of distillation columns is one of the vital reason for the failure, which can be enhanced through inherent safety concept. Therefore, this paper introduces a new indexing method for designing inherently safer distillation columns right from the preliminary design stage. Distillation Column Inherent Safety Index (DCISI) is based on three sub-indices; chemical index, process index and distillation index. These sub-indices are estimated through individual scores by considering various parameters in each category. For the unacceptable score, modification of process conditions is used to enhance safety level of the design. DCISI is estimated for all combination of conditions and lowest DCISI value indicates the inherently safer design of the distillation column.

The architectural design studio is the backbone of the education of future architects. It occupies a central position in architectural education. Thus design education in architecture like other kinds of education conserves and transmits the values of the profession & society at large. In recent years, it is widely noted that architectural practice has changed significantly and that several corresponding changes in the Design studio will be needed. The current approach to teaching architectural design follows principles & rules developed in the past and not equipped to confront the environmental needs of contemporary societies to a larger extent. It is suggested that future architects should be socially and ethically responsive, and should be able to function within social contexts.

This paper proposed a novel integrated design of azeotropic mixtures distillation process based on mechanical vapor recompression (MVR). The extractive distillation of acetone – methanol binary system that forms a homogeneous minimum – boiling azeotrope was studied. Based on the simulation result, the total energy consumption of the proposed sequence is 62% less than the existing extractive distillation configuration.

The experimental liquid–liquid equilibrium (LLE) data of the quaternary (acetic acid + water + pxylene + methyl acetate) system was investigated at 313.2 K and atmospheric pressure. This research is aimed to examine the potential of the mixture of methyl acetate and p-xylene, which available as the
remaining substances in terephthalic acid production, to be prospective extracting solvent for the acetic acid dehydration. LLE phase diagrams at different ratio of p-xylene to methyl acetate were presented for this quaternary system. The results showed that an enlargement of the LLE two-phase region occurred with increasing p-xylene to methyl acetate mass ratio in the initial solvent phase. The distribution coefficient and selectivity for the extraction of acetic acid were also obtained to evaluate the capability of solvent. LLE data were sufficiently correlated by Othmer-Tobias and Bachman equations. The experimental results were used to obtain binary interaction parameters as correlated by the nonrandom two liquid (NRTL) and universal quasi-chemical theory (UNIQUAC) equation models. The root mean square deviations (RMSD) values as low as 0.0119 and 0.0128 were calculated for NRTL and UNIQUAC, respectively; indicating excellent results for both models were suitable for the determination of LLE data of this quaternary system.

This work investigates a novel way of retrofitting a side stream column for achieving considerable energy savings by combining the dividing wall column (DWC) and heat pump system. One case study, the acetic acid (AA) purification process was illustrated to demonstrate the proposed methodology. Simulation of the combined configuration showed that energy saving was achieved up to 93.62 and 83.03% in the reboiler and condenser, respectively compared with a conventional column. Various configurations incorporating a heat pump were also analyzed. As a result, the combination of DWC and vapor recompression heat pump provides a promising way to the retrofit of a side stream column for improved energy efficiency.

EPDIP©, a model for enhancing natural intelligence to increase probability of success in any project: Part 1 – Structure, Process, People, Stage Gates, Implementation and Sustainability.
A novel stage gate process, the Enneagram Project Design and Implementation Process © (EPDIP), will be presented and explained.
That the model is closely based on the Dow Chemical Company’s  “Technology Design and Commercialisation Process” (TD&C), gives confidence that it is not an academic speculative theory but describes the actual processes followed by such companies as Dow to minimise risk (and cost) of project failure and increase probability of success at lowest cost.
The presentation will first outline the main features of DOW’s TD&C and then briefly describe the author’s adapted and simplified model for use in Chemin (The South African Chemical Technology Business Incubator). Chemin is one of about 8 Technology Incubators that were established by the DST in 2002/3 (part of DTI’s SEDA since 2005), some of which then also incorporated the Chemin stage gate model into their own incubation process.
The remainder of the presentation will show how DOW’s TD&C fits “The Intelligent Enneagram” model as elaborated in detail in A E Blake’s 1996 book with that title, and how the EPDIP© novel stage gate process developed by the author is a natural outcome.
This is a powerful model for enlarging our natural intelligence in many fields – business, science, arts, personal growth, evolution (biological and cultural), ethics and spirituality – and thus could be particularly useful for trans-disciplinary and cross-cultural collaborative developmental projects.

Keywords: Enneagram, development, project, implementation, sustainable, technology, business, intelligence.

EPDIP©, a model for enhancing natural intelligence to increase probability of success in any project: Part 2 – Application of the model towards integral developmental projects that alleviate rural poverty and violence.
The presentation will firstly illustrate the broad applicability of the novel Enneagram Project Development and Implementation Process© as described in Part 1 in various fields. More specifically the model will be used to show projects that attempt to develop “emerging farmers” along profit driven high energy input industrial farming models have a high risk of failure and are unsustainable. The agro-ecology alternative (in particular Permaculture Design) in contrast have a high rate of success and sustainability. By mapping these two contrasting agricultural approaches onto the EPDIP model is can be easily understood why; Permaculture Design, working with nature and not against it, aligns with and enhances the natural intelligence of rural communities whereas the industrial approach that attempts to control nature is unnatural.
The presentation will end with a brief outline of the author’s current research investigation on the feasibility of establishing a Permaculture Demonstration site at Tsolo College that will be linked to WSU and the local community. How the author is applying the EPDIP© model will be shared.

Key words: Enneagram, development, rural, sustainable, agro-ecology, permaculture, design, nature

The formulation of policies requires the selection and configuration of effective and acceptable courses of action to reach explicit goals. A one-size-fits-all policy is unlikely to achieve the desired goals; as a result, the identification of a suite of alternative policies, together with clear indications of their trade-offs, is crucial to accommodate the diversity of stakeholders’ preferences. At present, the formulation of transport policies is done manually; this fact, together with the size of the space of possible policies, results in a large part of that space being left unexplored. A six-step framework to explore the space of alternative transport policies in order to achieve environmental targets is proposed. The process starts with a user-defined set of specific policy measures, using them as building blocks in the generation of alternative policy packages, clusters and future images according to the user's preferences and goals.The analysis framework is based on the visioning and backcasting approach used in the VIBAT report [Banister, D., & Hickman, R. (2006a). Visioning and backcasting for UK transport policy (VIBAT) project. Department for Transport's Horizons Research Programme 2004/06. The Bartlett school of planning and Halcrow Group Ltd. Retrieved 1/18/2008 http://www.ucl.ac.uk/∼ucft696/vibat2.html]. The framework is being implemented as a prototype decision support system around a case study: the formulation and analysis of policies required to achieve CO2 emission targets for the transport sector in the UK. Important insights on how to develop the framework have also been elicited from engineering design. The goal is to accelerate the task of policy-making and improve the effectiveness of the resulting policies.The proposed method and computer implementation is fundamentally different from the tools commonly used in the transport sector and is intended to assist (not replace) transport policy makers, and complement (not substitute nor compete with) existing mathematical modelling tools. This research constitutes the first step towards the development of a general family of computer-based systems that support the design of policies to achieve environmental targets—not only for transport, but also for other sectors such as energy and water.

This work presents an optimisation framework for the routing and equipment design of main pipelines to be used for fluid transmission. There are many considerations in these design problems, involving various constraints, decisions and the associated costs for the construction, operation, maintenance, etc., of the system. In practice, engineers rely on experience, try out various design alternatives, and use simulators for engineering calculations, cost models, geographical information systems and equipment databases to identify promising options. The present approach proposes a systematic search for optimal and near-optimal solutions. The search is based on stochastic optimisation, and assumes that the same information and simulation tools as in the case of design by trial and error are available. An application example is used to demonstrate the approach and test the robustness of the optimal search using Simulated Annealing.

In this paper theoretical work is performed for the simulation of the model of a Reactive Batch Distillation Column (RBD). In this study first a dynamic model for RBD column is developed. In this model general reversible reaction with distillation is considered. The dynamic continuity equations of mass and energy balance are used for each unit operation in the process with reaction terms for the general reaction of the type
A+B C+D. These MESH equations taken together with reaction are considered as MESHR equations. Here
time varying Distillate and column hold up are chosen in the model which results highly non-linear coupled ordinary differential algebraic equations (DAEs). Raoult’s law and Wilson Model are taken for gas and liquid phase for vapor-liquid equilibrium (VLE) present in the column. These MESHR equations are set of DAEs. For solving these DAEs coding is done in Matlab for obtaining the optimum value of reflux ratio and the operation
batch time. Then the simulation is carried out for the optimum reflux ratio and the total batch time. A case study on esterification reaction is carried out to test the model for the given feed conditions. The results obtained are used to describe the dynamics performance of the RBD column.

This study examined the energy optimal operation of representative natural gas liquefaction cycle processes such as propane precooled mixed refrigerant (C 3 MR) process, dual mixed refrigerant (DMR) process, and modified single mixed refrigerant (MSMR) process. Steady-state optimality analysis in dynamic simulation environment was conducted to explore the operational behavior of each cycle. From this analysis, a steady-state optimality map that describes the relation between cost function and decision variable is obtained. By exploring this map a promising optimizing variable is discovered which further can be used to develop an energy optimizing control structure for the liquefaction process. Despite the same basic working principles, the operational behavior of the three cycles is dissimilar. The DMR has the narrowest optimal operation range while in the MSMR cycle the optimum value of cost function spans in relatively wide range of decision variable. The feasible operation of C 3 MR and DMR is bounded by the suction temperature of mixed refrigerant compressor while in the MSMR cycle this constraint is inactive. Based on the steady-state optimality analysis the temperature difference between the warm-end inlet and outlet MR streams (TD) were proposed to be a promising optimizing variable for the C 3 MR and DMR process while for the MSMR process the optimizing variable is the flow rate ratio of heavy and light mixed refrigerant (HK/LK ratio).

Coal becomes a key component of the energy source worldwide since it is the most abundant fossil fuel. Unfortunately, coal is the dirtiest fossil fuel so its environmental footprint needs to be reduced using a better technology. Integrated Gasification Combined Cycle (IGCC) serves the need of cleaner energy. This technology is developed to improve thermal efficiency and to reduce carbon dioxide emissions. This paper focuses on the dynamic behavior of a syngas treatment process in the IGCC power plant. The failure of the syngas treatment process will lead to performance reduction in the power block process. To avoid the process failure, a sophisticated process operability is needed to ensure the process can cope with inevitable disturbances. A dynamic model of the syngas treatment process was developed using Aspen Hysys ®.

T he use of visualization for heat exchanger network synthesis, both grass-roots and retro t, has a long history. Visualization is appealing to the user because it helps gain insight into the underlying problem. When coupled with user interaction, this insight generation can be enhanced. Furthermore, when the interaction includes access to an optimization procedure, the result is a tool that is appealing and has the potential to generate good results. This paper describes the implementation of an interactive visualization procedure for heat integrated process design. The visualization includes information about the underlying process responsible for the heating and cooling requirements which de ne the heat exchanger network synthesis problem. Furthermore, the data structures which underpin the visualization method provide a natural problem formulation for simulated annealing as an optimizer for the heat exchanger network structure. The combination of visualization, user interaction, and stochastic optimization results in a robust and easy to use tool for heat integrated process design.

In preliminary design, the space of design alternatives can be large. Automated synthesis tools may be used interactively to explore the design space, starting with a broad but coarse search and gradually progressing to more focussed and detailed searches. Recent developments in the search procedure used by the cHiPs process synthesis package enable the generation of partial solutions, solutions which although not feasible can be useful in the analysis of the synthesis problem. This enables one to use the tool as a device for exploration and experimentation. Furthermore, it provides a framework upon which the synthesis procedure can be expanded to provide automatic techniques for identifying suitable recycle structures. This paper briefly describes the approach for generating partial solutions. It demonstrates the use of the resulting tool in preliminary design through the presentation of a case study for the design of a Hydrofluoric acid plant, showing how the synthesis tool can be applied iteratively. The result is a process flowsheet suitable for more rigorous study. S53 $54 PSE '97-ESCAPE-7 Joint Conference m. ,,,.. ~ • m,...,-. ~,._(? t]jmm J glm H --m ol.bm ] J t * ,m

Design of an ammonia reactor was conceived as part of a series of item designs for an ammonia plant in Cyprus. The Chemical and Mechanical aspects of the design were considered. Optimization of these designs was studied, worked on, & discussed. The safety, environmental and legal regulations of relevant reactor regulations were followed in the design concerned.

We have devised a new route toward 2-unsubstituted pyrimidine derivatives from the Biginelli product, dihydropyrimidin-2(1H)-thiones in two steps: Oxidation of dihydropyrimidin-2(1H)thiones using oxone on wet alumina or hydrogen peroxide in the presence of catalytic amount of vanadyl sulfate provided 1,4-dihydropyrimidine, which was further oxidized to 2-unsubstituted pyrimidines by the treatment of KMnO 4 . Oxidation of dihydropyrimidin-2(1H)-ones by KMnO 4 formed 2-hydroxypyrimidine in excellent yield, whereas attempted direct desulfurative aromatization of dihydropyrimidin-2(1H)-thiones by KMnO 4 resulted in the formation of 2-hydroxypyrimidines, the same products obtained in the oxidation of dihydropyrimidin-2(1H)-one.

A pilot-plant process has been developed based on an innovative laboratory-scale method for
the recovery of scandium that exists in economically interesting concentrations in red mud, the
main byproduct of alumina production. This method includes acid leaching of the red mud pulp,
ion-exchange separation of scandium and lanthanides from the co-leached main elements such
as iron, and subsequent liquid-liquid extraction of the eluate for further scandium purification
and enrichment. In this work, experimental and theoretical investigation of the pilot-scale
leaching process was performed. The following parameters were tested: mode of agitation, solidto-
liquid ratio, acidity of the leachate, number of stages in the process, and pretreatment of red
mud with concentrated acids in order to achieve optimum scandium recovery combined with
low iron dissolution. Furthermore, by theoretical interpretation of the experimental data, a
predictive correlation for the scandium leaching efficiency was developed.

Interest in renewable resources, especially biomass has been increasing due to environmental issues from burning fossil fuels. Levulinic acid (LA), one of top twelve value-added chemicals from biomass, has been recognized in many applications. However, the LA industrial process has been limited by expensive feedstock and energy-intensive process. In this work, the process combining extraction and distillation producing levulinic acid (LA), furfural and formic acid (FA) from lignocellulosic biomass was studied. The effective process depends on the choice of the extracting solvent. The complete procedure for evaluating solvent from solvent screening to detailed LA production process was conducted. First, various solvents are evaluated and three promising solvents are selected to study further. Methyl isobutyl ketone (MIBK) solvent showed the most favorable equilibrium to extract LA and octanol solvent presented the most favorable result to extract FA, however furfural solvent showed the best overall performance. The furfural solvent process can recover LA more than octanol process and recover FA more than MIBK process. Second, the processes of three best solvents are designed and optimized by Aspen Plus simulator in terms of total annual cost to further comparison. The rigorous simulation results show that the process using furfural solvent can save 25.3% of energy consumption, 18.3% of total annual costs and reduce up to 17.9% of CO2 emission as compared to the octanol solvent process.

Following a 5 day course on Management of Technology by Prof Rias van Wyk at the University of Cape Town Business School in 1990, I explored how such an approach might be implemented. I was Chemistry R&D manager at the company at the time. In a restructuring process I was retrenched in early 1993 but was requested by one of the Company Directors (who saw the strategic value in this approach) to give a course to a group of senior managers. Later that year I was offered a contract research position 6 months later. See my CV and profile for an idea of my journey till now. Prof Van Wyk is still active and can be found on https://www dot linkedin dot com/in/rias-van-wyk-38ab4145