Vocabulary of Modern Process Engineering

This vocabulary is a list of terms and words used by professionals in the field of (process) engineering. Current sections include Process Scale-up, INtensification and Process and Product Design. Useful for those working in these fields. More vocabulary sections will be added to this page.

Vocabulary of Process Scale-up

I give courses on process scale-up. In these courses always questions arise about the meaning of terms. Here are some definitions of terms and also alternative definitions. The general advice is always to ask further explanation if terms  below are used.

Scale-up is generating knowledge to transfer ideas into successful commercial implementations [1]. An alternative definition. Scale-up is a larger production scale [2].

Scale-up factor is the capacity increase from one innovation stage to the next stage [3].

Micro-flow reactor (or process) is a continuously operated reactor (or process) at laboratory scale [1]. An alternative definition. “Microreactor technology is concerned with chemical reactions and unit operations in components and systems whose characteristic dimensions range from sub-milli-meter down to sub-micro-meter region” [3].

Mini-plant is a down-scaled version of the commercial scale design made in the feasibility stage [1]. An alternative definition. A mini-plant is a continuous complete laboratory plant containing reactors separators and recycle streams producing up to 100 gram/h. [3]

Pilot-plant is a down-scale version of the industrial scale process design to clarify all design and operating issues [1,3].

Demonstration plant (Demo-plant) is the first of its kind radically novel commercial scale plant with a 1-10 % capacity scale of the full commercial scale plant [4].


  • [1] Harmsen J, 2019, Industrial Process Scale-up – A Practical Innovation Guide from Idea to Commercial Implementation, DE GRUYTER, Berlin.
  • [2] Haan AB de 2015, Process Technology – An Introduction DE GRUYTER, Berlin
  • [3] Vogel GH 2005, Process Development – From the Initial Idea to the Chemical Production Plant, Wiley-VCH, Weinheim. [4] Harmsen J. 2018, Product and Process Design – Driving Innovation, DE GRUYTER, Berlin.

Vocabulary of Process Intensification Field

I review papers on the subject of Process Intensification (PI). Often the researchers struggle with the proper use of terms. I also give a course on PI for industrial chemical engineering practitioners. In some cases, participants struggle with the meaning of terms used. I therefore made a brief list of terms misunderstood or misused in the Process Intensification field. For each term I give a definition and for some terms also a reference.

Process Intensification is a set of radically innovative process design principles which can bring significant benefits in terms of efficiency, cost, product quality, safety, and health [1] over conventional process designs based on unit operations [2].

Modular design is a detailed process engineering design of modules, which can be easily connected to each other (plug in principle), The modules are detailed process engineered and constructed by an Engineering Procurement Construction (EPC) company [3]. Each module can be constructed many times using the same detailed design [3].

Skid mounted means that the process plant or modules are constructed inside a skid frame. The process plant is constructed at the EPC company, dry tested and then transported to the manufacturing site [3]. Most modular designed processes are skid mounted.

Distributed process plants means that many small capacity process plants are distributed over various locations. To keep the investment cost per ton of product at acceptable levels often the process concept design is based on process intensification methods, while the detailed process engineering is based on modular design and the construction is skid mounted.

Conventional Stick Built is the conventional constructing the process plants at the manufacturing site. It is the opposite of modular design with skid mounted construction.

Building Blocks are the process intensified versions of unit operations of a process design. [3].

Functional process design is conceptual process design based on functions and function integration [2,3] rather than on established unit operations.

Numbering up is a term used my many people and often each mean something different. The presenter may mean having many of the same equipment pieces parallel to each other but connected to the same input and output device. The presenter may mean having process trains in parallel to each other on the same manufacturing site. The presenter may mean a linear investment cost curve with production capacity. Often the last meaning is wrongly connected to the other meanings. Even with parallel process trains the total investment cost correlates in most case with the capacity to a power less than 1. As a lot of construction cost, such as buildings, concrete floors, pillars, and others are still shared. So, ask for clarification when “numbering up” is used.


  • [1] Stankiewicz. A, Gerven, van T. Stefanides, G, The fundamentals of process intensification, Wiley-VCH, Weinheim, 2019.
  • [2] Harmsen, J, Verkerk, M, Process Intensification, De Gruyter, Berlin, 2020.
  • [3] Harmsen J, Verkerk M, A New Approach to Industrial Innovation. CHEMICAL ENGINEERING PROGRESS. 2021 Mar 1;117(3):50-3.

Vocabulary Sustainable Design of Processes and Products

Here is a shortlist of terms relevant to Sustainable Design of Products and Processes.

Sustainable development is not a fixed state of harmony, but a process of change in which the exploitation of resources, the direction of investments, the orientation of technological development and institutional change are made consistent with future as well as present needs. Sustainable development is development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs” [1].

Sustainable Development Goals are the main part of the United Nations Sustainable Development Agenda 2030[2].

Life Cycle Analysis concerns all environmental impacts attributable to the functioning of a product over its life cycle, cradle to grave (abbreviated) [3].

Industrial ecology is the study of the flows of materials and energy in industrial and consumer activities, of the effects of these flows on the environment, and of the influences of economic, political, regulatory, and social factors on the flow, use and transformation of resources [4].

Industrial Symbiosis is a subset of industrial ecology. It is concerned with transferring the biology analogy of the eco-system to the industrial system [5].

A circular economy is one that is restorative and regenerative by design, and which aims to keep products, components and materials at their highest utility and value at all times, distinguishing between technical and biological cycles [6].


[1] Brundtland GH, 1987, Our Common Future, report World Commission on Environment and Development of the UN.
[2] UN 2015, Transforming our world: The 2030 Agenda for Sustainable Development, Resolution General Assembly U.N.
[3] Schaschke C, 2014, Oxford Dictionary of Chemical Engineering, Oxford U. Press, Oxford (UK).
[4]Ayres RU, 2002. Ayres LW, A handbook of Industrial ecology, Cheltenham USA: Edward Elgar Publ. Ltd, 2002.
[5] Chertow, MR 2007, Uncovering industrial symbiosis, Journal of Industrial Ecology 11.1, 11-30.
[6] Ellen MacArthur Foundation, circular economy scheme. resourced from; https://www.ellenmacarthurfoundation.org/circular-economy/interactive-diagram

Vocabulary Innovation Steps Products and Processes

Here is a shortlist of terms used for product and process innovation stages in industries [1].

In the Discovery stage new ideas are generated and proof of principle experiments are carried out. This stage is also called Ideation stage.

In the Concept stage ideas are defined to a concept and proof of concept experiments are carried out.

In the Feasibility stage the commercial feasibility of the new product and or process is defined.

In the Development stage the new product and or process is tested in a mini-plant or pilot plant. The stage ends with a Front-End-Engineering Loading (FEED) document.

The Engineering-Procurement-Construction (EPC) stage results in the commercial scale process.

In the Start-up stage the new product and or new process is produced for market sales.


[1] Harmsen J 2018, de Haan AB, Schwinkels PLJ, Product and Process Design – Driving Innovation, DE GRUYTER, Berlin.