This monograph provides foundations, methods, guidelines and examples for monitoring and improving resource efficiency during the operation of processing plants and for improving their design. The measures taken to improve their energy and resource efficiency are strongly influenced by regulations and standards which are covered in Part I of this book. Without changing the actual processing equipment, the way how the processes are operated can have a strong influence on the resource efficiency of the plants and this potential can be exploited with much smaller investments than needed for the introduction of new process technologies. This aspect is the focus of Part II. In Part III we discuss physical changes of the process technology such as heat integration, synthesis and realization of optimal processes, and industrial symbiosis. The last part deals with the people that are needed to make these changes possible and discusses the path towards a resource efficiency culture. Written with industrial solutions in mind, this text will benefit practitioners as well as the academic community.
Part I Resource Efficiency Metrics and Standardised Management Systems
Chapter 1 Energy and Resource Efficiency in the Process Industries
Stefan KrÀmer1 and Sebastian Engell2
1INEOS Köln GmbH, Alte Str. 201, 50769 Köln, Germany
2Technische UniversitÀt Dortmund, Department of Biochemical and Chemical Engineering, Emil Figge-Str. 70, 44221 Dortmund
1.1 Introduction
Climate change, reduced access to fresh water, loss of biodiversity and pollution are possible downsides of industrial production. Among the different sectors of industrial production, the sector of the chemical and process industry has a relatively large impact on resources and on the environment as most production units in this sector use natural, often non-renewable resources directly or via their supply chains. One main goal of current environmental policies is to slow down global warming by decreasing CO
emissions. The most significant measure in this direction is to switch to renewable resources in the generation of electric power, heating of buildings and industrial production. When the source of raw materials cannot be changed in the short or medium term, an important intermediate step is to increase the overall resource efficiency, in power generation as well as in industrial production.
Energy efficiency has been a prominent topic of public discussion, scientific research and engineering; it is covered in many books and publications as well as by legislation. Resource efficiency has been on the research agenda for a while; and although many large companies have started to embrace the concept of resource efficiency [1â5], it is not as visible as energy efficiency to the general public. For this reason, the countries of the European Union recently started extensive studies (e.g. âResource efficiency as a challenge for the basic chemical industry in Germanyâ [6]) and research and innovation projects and support actions within FP7 and Horizon 2020 on a European level or ProGress I and II in Germany. Still, resource efficiency remains less clear as an overall concept supporting the efficient utilization of resources, as it is not as easily grasped as the concept of energy efficiency which concerns one single physical variable and leads to one indicator. Resources, in contrast, encompass a large spectrum of inputs that are used in production, including many resources that people do not think of immediately, such as fresh water, natural gas as a raw material for chemicals, precious metals, land use or biodiversity.
This chapter intends to provide an understanding of what is meant by resources and resource efficiency specifically in relation to the chemical and process industry. It summarizes the major measures towards a more resource-efficient process industry and relates them to the subsequent chapters of the book.
In many industries, energy such as heat and electrical power can be treated separately from raw materials; raw materials are converted into products using energy. The general term resources is not even used in those industries, or raw materials and indirect indicators such as land use are treated as resources, but energy is not included. In the process industry, especially the chemical industry, energy and raw materials need to be treated together as resources; the focus on energy alone is not enough. While many production processes in the manufacturing industries, e.g. the automotive industry, shape and assemble pieces of material, processes with chemical reactions convert materials from one to another, convert materials into energy and sometimes also carriers of energy into materials â for example, in the case of ammonia production where natural gas and air are converted to ammonia. The plants often use raw materials that in other industries would be considered as (carriers of) energy such as natural gas or oil.
The process industry, especially the chemical industry combines chemical reactions often with energy-intense separation processes. This is, on the one hand, resource- and energy-intensive; on the other hand, chemical plants convert resources into products with little waste heat and emissions. The overall resource usage is therefore often much higher than in other industries, but much of the resources, especially the carbon, is bound in long-life products. With cost being the main driver, efficient use of resources and waste minimization have been a key concern of the process industry since the first plants were built. Linnhoff developed heat integration before any environmental legislation existed [7]. Nonetheless, further efforts for resource-efficient production are needed for a sustainable industry in the future.
1.2 Energy and Resources
1.2.1 What Do We Mean by Energy and Resources?
Physically, the term energy is well defined. It can appear in a number of different forms such as potential, kinetic, chemical energy and many others. It is fundamental in the domain of thermodynamics, as the first law of thermodynamics states that energy is always conserved and, in contrast to common language, is not consumed but only converted from one form to another. When engineers and plant managers talk about energy, they typically have in mind the energy inputs that they need to operate their plants â normally, steam, electric power, natural gas or other fuels. So the concept is similar to that of exergy, which is the energy that is available to be used for the given purpose and can be utilized and transformed, for example, into mechanical work.
The term resource is more broadly defined: âNatural resources are materials and energy in nature that are essential or useful to humansâ [8, p. 9].
Resources needed to make products in the process industry can be defined in a more limited manner. In the context of this book, our understanding is:
Resources are the environment, land, air and water, and all materials and the energy required to make the desired products.
Human labour and human creativity without doubt are also precious resources, but when we speak of resource efficiency in this book, we leave this element out of the discussion.
1.2.2 Classification of Energy and Resources
The energy required for process operation can be classified into primary energy and secondary energy. Primary energy is defined as the energy that is directly provided by nature, for example, sun and wind, or contained in materials that are found in nature and that has not been converted into a different form of energy. Primary energy can be subdivided into non-renewable sources such as natural gas, oil or uranium and renewable sources such as solar and w...
