A Mixed Integer Linear Programming (MILP) Model for Optimal Design of Water Network

This work presents the development of a new systematic technique to target fresh water consumption and wastewater generation for systems involving multiple contaminants when all options of water minimization including source elimination, reduction, reuse/recycle, outsourcing and regeneration are considered simultaneously. This problem is formulated as mixed integer linear programming (MILP) and implemented in Generalized Algebraic Modeling System (GAMS). The consideration of process changes will lead to optimal design of minimum water utilization network. The MILP model proposed in this work can be used to simultaneously generate the minimum water targets and design the minimum water network for global water-using operations for buildings and industry. The approach is illustrated by using an industrial involving a chlor-alkali plant. Significant water savings for the industrial case study is achieved, illustrating the effectiveness of the proposed approach

1st Process systems engineering & safety (ProSES) symposium 2019 preface

The special issue of 1st ProSES Symposium is a collection of invited contributions from the presenters of the inaugural Process Systems Engineering & Safety (ProSES) Symposium, organized by Process Systems Engineering & Safety (ProSES) Research Group, Faculty of Chemical and Process Engineering Technology, formally known as the Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, on 4th September 2019 in Kuantan, Pahang, Malaysia. The theme for the 1st ProSES Symposium 2019 is The Role of Modelling and Simulation Towards IR 4.0, since the emergence of IR4.0 technology provides the opportunity for dramatically increasing the reliability and efficiency in production operations of many industrial sectors including chemical-based processing. Hence, it is the aim of this conference to provide the platform for intellectual discourse for the application of computer aided tools for modelling and simulation in the area of process systems engineering and safety particularly in the era of IR4.0, and related topics. 1st ProSES Symposium 2019 attracted more than 60 extended abstracts submissions. Two keynote speakers delivered their particularly interesting topics – Professor Ir Dr Haslenda Hashim from Universiti Teknologi Malaysia with a talk on "Process Modelling and Simulation Toward IR4.0"; and Professor Dr Azmi Mohd Shariff from Universiti Teknologi Petronas on "Process Safety in IR4.0"

Optimal design of water networks involving single contaminant

This work presents the development of a systematic technique to target freshwater consumption and wastewater generation to achieve the maximum water recovery for systems involving single contaminant. A generic linear programming (LP) model has been developed based on water network superstructure to simultaneously generate the maximum water recovery targets and design minimum water network, for both mass transfer-based and non-mass transfer-based problems (i.e., global water-using operations). The approach is illustrated by using an urban case study involving a mosque and an industrial case study involving an acrylonitrile process. The results show the potential maximum freshwater and wastewater reduction are 43.4% and 49.3% respectively for Sultan Ismail Mosque, and 70.6% and 37.7% for acrylonitrile process, which agree with the previous study performed using water cascade analysis techniqu

Superstructure optimization of bioethanol production from corn stover

Bioethanol is a liquid fuel that can be produced from various raw materials. The first generation of bioethanol which are starch and sugar has begun to decline as these materials are considered to be the food sources for human as well as animals. However, the rise of production of bioethanol from the second generation which are the lignocellulosic materials has been proven to give a lot of benefits to mankind instead. Various technologies were studied in order to develop a systematic approach for designing an optimal processing route for bioethanol production from lignocellulosic biomass. A superstructure on the available process technologies which include the three main technologies, the pretreatment, sugar conversion, separation and purification was first developed before screening it down to a final superstructure. All of the data to be used in this study were collected from open literature and followed by the selection and development of the models required in order to solve the generic models and problems by using an optimization software, the Generic Algebraic Modelling System (GAMS). The results of software GAMS indicate that the optimal processing route in producing bioethanol from lignocellulosic biomass include the technologies of steam explosion, dilute acid followed by fermentation, beer and dehydration of ethanol on zeolite for each process interva

Synthesis of inter-plant water network involving multiple contaminants

Minimization of freshwater consumption and wastewater generation are being critical concerns in the process industry due to the increase scarcity in freshwater supply, the rise of freshwater and effluent treatment costs and more stringent regulations. One of the efficient ways to reduce freshwater consumption in the process is by recycling and/or reusing wastewater that is generated by the process or utility after being treated to acceptable limits. Traditional industrial water conservation practices mainly focused on the 3R strategy (reduce, reuse and recycle) within an individual plant and this strategy can be implemented by using water system integration technique. In order to improve the water recovery, Chew et al. [1] extends the single plant water network into integration of inter-plant water network via cross-plant pipelines or centralized utility hub. This work presents the development of a systematic approach for synthesizing indirect inter-plant water network integration with centralized regeneration system involving multiple contaminants. In this approach, water reuse prospects were analysed within individual plants and between different plants via inter-plant water integration possibilities. The water network problem is formulated as mixed integer nonlinear programming (MINLP) solved based on the water network superstructure. The applicability of the proposed approach is illustrated using an industrial case study. At the end of this study, significant reductions of freshwater consumption and wastewater generation have been achieved, showing the effectiveness of the proposed approach. The results obtained give higher percentage reduction of the freshwater consumption and wastewater generation is 47.61% and 53.48% respectively

Kinetic study of asymmetric synthesis of chiral amine with immobilized transaminase

Biocatalysis is a powerful tool for organic synthesis, especially for the synthesis of high value products such as chiral molecules and intermediates. Chiral amines can be synthesized by kinetic resolution of racemic amines or by the asymmetric synthesis from prochiral ketones. Kinetic parameter estimation of such biocatalytic reaction is useful to evaluate process and technology options. In this research, the Michaelis–Menten kinetic parameters from the asymmetric synthesis of (R)-1-phenylethylamine from acetophenone and alanine with immobilized ω-transaminase were estimated. The immobilized ω-transaminase was prepared by entrapment with diaion beads. The kinetic parameters such as, Michaelis-Menten constant (Km) and maximum rate of reaction (Vmax) were measured using initial rate experiments by varying the substrate acetophenone concentrations (2 mM to 10 mM) at 100 mM of amino donor. The kinetic parameters were then estimated by Lineweaver-burk analysis. The Vmax and Km was estimated at 6.33 mM/min and 0.382 mM, respectively