Sustainable Process Integration and Intensification

Jiří Jaromír Klemeš, Petar Sabev Varbanov, Sharifah Rafidah Wan Alwi, Zainuddin Abdul Manan, Yee Van Fan, Hon Huin Chin

• Publisher: De Gruyter
• Year: 2018
• eBook ISBN: 9783110535549
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Environmental Science

1Process Integration and Intensification: An Introduction

Numerous studies are being performed on improving the efficiencies of the supply and utilization of energy, water, and other resources while simultaneously reducing pollutant emissions. This vital task is the focus of this textbook. It has been estimated that the majority of industrial plants throughout the world use up to 50 %more energy than necessary (Alfa Laval, 2011).

Usually, reducing resource consumption is achieved by increasing the internal recycling and re-use of energy and material streams. Projects for improving resource efficiencies can be very beneficial and also potentially improve the public perceptions of companies. Motivating, launching, and carrying out such projects, however, involve proper optimization, based on adequate process models.

As a response to these industrial and societal requirements, considerable research effort has been targeted towards Process Integration (PI) and Process Intensification (PIs). After a short assessment of these advanced engineering approaches, this handbook makes an attempt to describe the methodology that can lead a potential user through the introductory steps. This introduction provides a short overview of the historical development, achievements, and future challenges. After the introduction, the text focuses on Process Integration as an important engineering tool that can be exploited to achieve the goals of Process Intensification.

1.1Process Intensification

There have been several initiatives supporting development in this area. One of them is the Process Intensification Network – PIN (PINET, 2013). This network declared that Process Intensification (PIs) was originally conceived in ICI (at that time, the Imperial Chemical Industries plc) as “the reduction of process plant volumes by two to three orders of magnitude”. PIs targeted at that time the reduction of capital cost, primarily by minimizing equipment installation factors, which involve piping, support structures, etc. It has since become apparent that a rigorously pursued strategy of PIs has far wider benefits than mere CAPEX (Capital Expenditure funds used by a company to acquire or upgrade physical assets such as property, industrial buildings, or equipment) reduction, and its definition has accordingly been softened to include very significant plant size reductions based upon revolutionary or “step-out” new technology. PIs is not a mere evolutionary “apple-polishing” exercise of incremental development.

The benefits of PIs have extended far beyond the CAPEX reductions envisaged years ago. The iron grip, which can now be imposed upon the fluid dynamic environment within a reactor, means that improved selectivities and conversions can usually be achieved.

However, the former ICI head of manufacturing technology Roger Benson said that after years of false starts, the time has come for Process Intensification (PIs) technologies to make a major breakthrough in the chemical and process industries (IChemE, 2011).

The PIN web site (PINET, 2013) summarises the advantages as

1. Better product quality;
2. Just-in-time manufacture becomes feasible with ultra-short residence times;
3. Distributed (rather than centralized) manufacture may become economical;
4. Lower waste levels reduce downstream purification cost and are conducive to “Green” manufacture;
5. Smaller inventories lead to improved intrinsic safety;
6. Better control of process irreversibilities can lead to lower energy use.

PIs can help companies and others meet all of these demands in the process industries and in other sectors. The PIN network ahelps companies to compete, and helps researchers target successful research goals. HEXAG is an international association of organisations involved in the manufacture and use of heat exchangers. PIN and HEXAG (HEXAG and PIN, 2013) help students to gain an awareness of PIs for future use in their employment.

A kind of a bible of PIs has been published by Reay et al. (2008) and a very recent updated version (Reay et al., 2013). It covers main issues such as PIs as compact and micro-heat exchangers; reactors; intensification of separation processes; mixing; application areas in petrochemicals and fine chemicals; off-shore processing; miscellaneous process industries; the built environment, electronics and the home; specifying, manufacturing and operating PI plants.

Reay et al. (2013) correctly stated that the heat transfer engineer notes that “intensification” is analogous to “enhancement”, and intensification is based to a substantial degree on active and, to a lesser extent, passive enhancement methods that are used widely in heat and mass transfer.

There has been also a Working Party on Process Intensification (2013). Their mission statement declares:

Process Intensification presents one of the most significant developments in chemical and process engineering of the past decennia. It attracts more and more attention of the chemical engineering community. Several international conferences, smaller symposia/workshops every year, books and a number of dedicated issues of professional journals are a clear proof of it. Process Intensification with its ambition and ability to make chemical processing plants substantially smaller, simpler, more controllable, more selective and more energy-efficient, addresses the fundamental sustainability issues in process industry and presents the core element of Green Chemical Engineering. In many research centres throughout Europe and the world numerous PIsoriented research programs are carried out. Process Intensification is taught at various courses and gradually enters the regular university curricula. In the UK and in the Netherlands national PIs networks have been operated for a number of years. A similar network is being formed in Germany (DECHEMA, 2013). Process Intensification plays an important role in the CEFIC’s Technology Platform on Sustainable Chemistry (CEFIC, 2013). Process Intensification has now established its organisational position within the European Federation of Chemical Engineering.

The PIs WP has been organizing annual conferences under the title European Process Intensification Conference (EPIC, 2013) and the sucessful story continues. The previous EPIC conferences were held in Copenhagen in 2007, Venice in 2009 and Manchester in 2011.

1.2Process Systems Engineering and Process Integration

PIs have been very much targeted at processing units. On the other hand, Process Integration (PI) has developed a methodology by which PIs can be very beneficial at the system level. PI has been an important part of Process Systems Engineering, which is handled by the Working Party of Computer Aided Process Engineering of the European Federation of Chemical Engineering (CAPE-WP, 2017). It has been one of the longest-serving working parties. Its definition is as follows:

Computer Aided Process Engineering (CAPE) concerns the management of complexity in systems involving physical and chemical change. These systems usually involve many time and scale lengths and their characteristics, and the influences on them are uncertain. CAPE involves the study of approaches to the analysis, synthesis, and design of complex and uncertain process engineering systems and the development tools and techniques required for this. The tools enable process engineers to systematically develop products and processes across a wide range of domains involving chemical and physical change: from molecular, thermodynamic and genetic phenomena to manufacturing processes and to related business processes. The Working Party promotes the development, study, and use of CAPE tools and techniques.
The main characteristics are: Multiple scales, uncertainty, multidisciplinary, complexity.
Core competencies: Modelling, synthesis, design, control, optimisation, problem-solving. Domains: manufacturing products and processes involving molecular change, sustainability, business processes, biological systems, energy, water.

The CAPE Working Party (CAPE-WP, 2017) main venue has been ESCAPE – European Symposium of Computer Aided Process Engineering, whose first venue was already organized in 1992 in Helsingør, Denmark. The 2014 ESCAPE conferences were in Budapest (ESCAPE 24, 2014), Copenhagen in 2015, Portoroz in Slovenia in 2016, Barcelona in 2017 (CACE, 2017) and Graz in 2018 (CACE, 2018). The CAPE WP has also collaborated with EURECHA to organize the the CAPE Forum.

PI roots as deep as 1972 and has been pioneered by several research centers, originally in the UK (UMIST Manchester), Japan, and the US. However, over the years the methodology and research spread out over the world. In most recent years especially Asian researchers have become very active and are more and more leading the effort. There have been numerous publications devoted to PI for more than 40 years of development covering methodology, and industrial implementations, providing valuable feedback to researchers (Chew et al., 2013). A number of excellent reviews has also been presented. The most recent is the Handbook of Process Integration (Klemeš (ed.), 2013). The vast majority of leading PI researchers contributed to that handbook with their unique expertise.

PI has been holding conferences for two decades: PRES – Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction. The 20-year Jubilee Conference was PRES’17 (2017), organized by Tianjin University and Hebei University of Technology, in Tianjin, China, 21–24 August 2017 and in 2018 in Prague, Czech Republic, where the number of submitted abstract reached 550.

1.3Contributions to PIs and PI to energy and water saving

To save energy on a large scale and on a global basis, companies taking ownership and responsibility for new plants clearly need to question the energy efficiency of the equipment and layout recommended to them by the proposing contractors. Historically, designers and builders of process plants have not been asked or been paid to critically review the energy-efficiency options available to their clients, preferring to offer low risk, easy-to-replicate and therefore easy-to-guarantee generic designs. For existing plants, reducing energy consumption can be more challenging than is the case for grassroots developments.

PI supporting Process Design, Integration, and Optimization has been around for more than 40 years (Klemeš and Kravanja, 2013) and at present the history has reached 45 years (Lee et al., 2018). Its on-going development has been closely related to the development of Chemical, Power, and Environmental Engineering, the implementation of mathematical modelling, and the application of information technology. Its development has accelerated over the years, as its methodology has been able to provide answers and support on important issues regarding economic development – better utilisation and savings regarding energy, water, and other resources.

1.4What is Process Integration?

Process Integration (PI) is a family of methodologies for combining several parts of processes or whole processes to reduce consumption of resources and prevent release of harmful emissions to the environment. PI began mainly as Heat Integration (HI) stimulated by the energy crises of the 1970s. HI has been extensively used in the processing and power-generating industries 45 years now. PI examines the potential for improving and optimising the Heat Exchange between heat sources and sinks, aimed at reducing the amount of external heating and cooling, together with the related cost and emissions. It provides a systematic design procedure for energy recovery networks.

HI (using Pinch Technology) has several definitions, almost invariably referring to the thermal combination of steady-state process streams or batch operations for achieving Heat Recovery via Heat Exchange. More broadly, the definition of PI, as adopted by the International Energy Agency (Gundersen, 2000) reads as follows:

Systematic and General Methods for Designing Integrated Production Systems ranging from Individual Processes to Total Sites, with special emphasis on the Efficient Use of Energy and reducing Environmental Effects.

Reducing an external heating utility is usually accompanied by an equivalent reduction in the cooling utility demand (Linnhoff and Flower, 1978). This also tends to reduce the CO2 emissions from the corresponding sites. Reduction of wastewater effluents based on Water (Mass) Integration can also lead to reduced freshwater intake (Wang and Smith, 1994), as demonstrated in industrial implementations elsewhere (Thevendiraraj et al., 2003).

1.5A short history of the development of Process Integration

Several methodologies emerged in late 1970s in response to these industrial and societal challenges. One of them was Process System Engineering (PSE) (Sargent, 1979) and later extended again by Sargent (1983). Another methodology that received world prominence was Process Integration” (PI) (Linnhoff and Flower, 1978). PI was first formulated in the first PI book by Linnhoff et al. (1982). Its development was further contributed to by a number of works from UMIST, Manchester, UK and other research groups.

It is remarkable that researchers have never lost interest in PI during the last 40 years and it has even been recently flourishing. HI has proved itself to have a considerable potential for reducing the overall energy demand and emissions across a site, leading to a more effective and efficient site utility system. One of the first related works was by Hohmann (1971) in his PhD thesis at the University of Southern California. This work was the first to introduce systematic thermodynamics-based reasoning for evaluating the minimum energy requirements of a Heat Exchanger Network (HEN) synthesis problem. Various approaches dealing with the optimum HEN synthesis have since been published. Some of them have become ver...

Table of contents

• Cover
• Title Page
• Copyright
• Preface to the 2nd edition
• Preface
• Contents
• 1 Process Integration and Intensification: An Introduction
• 2 Setting energy targets and Heat Integration
• 3 Synthesis of Heat Exchanger Networks
• 4 Total Site Integration
• 5 An Integrated Pinch Analysis Framework for Low CO2 Industrial Site Planning
• 6 Introduction to Water Pinch Analysis
• 7 Setting the maximum water recovery targets
• 8 Water network design/retrofit
• 9 Design of Cost-Effective Minimum Water Network (CEMWN)
• 10 Conclusions and sources of further information
• Index