In many US chemical engineering departments there is virtually no research in engineering or chemical engineering science. In such departments, most work would fit comfortably within a chemistry, biology or physics departments, except that the chemical engineer holds onto the idea of producing a product as a result of the research. This is the major distinguishing feature between chemical engineering and the sciences. By seeking to produce a product, rather than pursuing knowledge for its own sake, chemical engineers will use all the tools and knowledge of the sciences and may pursue similar projects, but have quite different research objectives. The key approach is the acquisition of new techniques from science as rapidly as they develop, and using them to create new entities rather than to study the nature of matter.

There are still some departments with strong programmes in PSE and chemical engineering science. Process systems programmes exist at Carnegie Mellon, Purdue, and the University of Massachusetts for example (with a few scattered individuals elsewhere). In the past, work was restricted to large continuous petrochemical processes, but now deals with batch systems, advanced computer technology, and non-linear development of chemical process modelling. Topics covered include non-linear analysis of bifurcation theories, process design of polymer processes and batch processes, integration of plant design and control, robust design of control systems, plant wide control, and separation synthesis systems. Process systems engineers also study process synthesis, large-scale non-linear and mixed-integer optimisation, modelling and simulation, scheduling and planning of multiproduct plants.

Berkeley however, has moved away from process systems engineering. They regard PSE as necessary for the industry, but as a member of staff explained

Other traditional areas continue to be of considerable interest in the US. However, there is a strong shift to considering the problems on the molecular scale, and not the macro-scale, as has been traditionally the case. Again, as new analytical and microscopic techniques have been developed in pure science arenas, US chemical engineers have been quick to exploit these new tools, and to develop their further understanding. Princeton, for example, carries out CES in the following areas:

• interfacial phenomena at the molecular level,
• linking polymer synthesis to novel molecular structure and resultant properties,
• the hydrodynamic and electrical forces intrinsic to complex fluids,
• the non-linear dynamics of fluidised bed transport, and the
• non-linear optimisation of process systems,.

These are difficult problems to make headway in, simply because most of the easy approaches have already been investigated. The areas require an understanding of molecular level and intermediate level forces. They could readily be carried out by physicists, chemists or material scientists who had the inclination to do so. Their faith in chemical engineering science remains strong;

The major broad areas of research now active in the departments which we visited are all following major trends probably driven in part by the funding agencies. There are a number of fields which are very active in the USA, but which do not seem to have much activity in the UK, and discussion of some of these important areas follows. These include:

• biochemical and biomedical engineering - focusing on metabolic engineering and cellular processes rather than bioprocess engineering
• materials - covering polymer design and self-assembly, microelectronic materials, complex fluids, colloids and interfacial engineering
• environmental problems - atmospheric chemistry, bioremediation and atmospheric modelling
• catalyst synthesis
• molecular modelling

The table below indicates how popular the broad areas of chemical engineering are in the US, and sets out some examples of the type of projects currently underway. For comparison, figures are drawn together for the UK. The data was gathered from departmental web sites, and personal web pages in both cases. As can be seen, there are some stark differences in not only the type of work being carried out, but also in ethos and approach. The UK trumpets immediately how industrially relevant their work is and tends to be solving the problems which industry currently is experiencing. Whereas the US approach can be summed up by:

Some of these differences are discussed below, but it should be remembered that US chemical engineers are still doing ChE, though with a new set of problems. They are taking the core chemical engineering tools and adding one or two others taken from the sciences and applying them to solve the problems of a different range of industries. The essential quantitative problem solving approach and core tools remain common. It should be emphasised that the examples are simply that, examples. There are of course people working on a wide range of topics in both countries, but we believe that this represents a general perception of the current state.

Many good chemical engineering departments now have substantial materials interests. For example, Minnesota is a joint department (Chemical Engineering and Materials Science) where most of the research could be classified as material science or biochemical/biomedical engineering. Even the biomedical engineering has a materials emphasis (the development of new tissues and organs). The success of the chemical engineering approach in the US has been put succinctly:

An area now entrenched in chemical engineering is electronic materials and the preparation of advanced materials in general. Techniques such as chemical vapour deposition, modelling and control, plasma processing, electrochemical processes, solid state chemistry, and surface science are considered to be the realm of pure science in the UK – not so in the US. There is manufacturing sector in electronic materials, and therefore it is fair game for chemical engineers and the chemical engineering community. In addition to the experimental tools for characterising these materials, numerical methods for simulations are also embraced by chemical engineers. Clearly, applications associated with the strong microelectronic industries in California and Texas have been highly influential in attracting/driving chemical engineers. However, in spite of considerable activity , it is still considered that chemical engineering has been missing opportunities in semiconductor growth and electronic materials in general.

This area includes: colloids, microstructured fluids, and self assembled molecular arrays. There are many fields of research here which require skills in Computational Chemistry and Physics such as: nanoscopically confined fluids, molecular theory of fluids contained in porous media, molecular theory of solid fluid phase equilibria, and surface diffusion. Also of increasing interest in the US are subjects requiring skills in Interfaces and Colloidal Engineering: self assembled structures, and microstructured fluids as separation materials, complex fluid systems which include "colloidal dispersions" of two immiscible phases (oil-water emulsions or dispersions of solid particles in water) or "association colloids" formed by self-assembly of soluble surfactants or polymers.

Furthermore, basic studies of polymers from the atomic and thermodynamic standpoint (polymer blends, block copolymers, thin films, polymer interfaces, polymer melt dynamics, relaxation processes in inorganic glasses) are very widely studied. Also receiving considerable funding is the statistical thermodynamics of bulk and surface properties of polymer liquids and supramolecular liquids.

The UK has a lot of work in environmental chemical engineering, and covers most of the fields active in the USA (air pollution, combustion, pollution prevention, waste minimisation etc). Though there is possibly not so much on atmospheric modelling carried out by UK chemical engineers. In the US this includes researching complex atmospheric chemistry models for air pollution (smog, acid rain, global), studying the formation and properties of aerosols, heterogeneous atmospheric chemistry, and bioremediation of soils and solutions. Such work is being carried out in the UK, just not usually by chemical engineers.

Whilst roughly the same proportion of UK and US chemical engineers work in biochemical engineering, the UK is much more concerned with industrial bioprocesses, food technology. The US has moved on from this into new areas, and is particularly expanding into biomedical engineering. For example, the Centre for Bioprocess Engineering at MIT used to work on downstream processing and cell culture, but now the emphasis has shifted to cellular processes and nucleic acid technology, protein design and production (protein engineering, gene expression), cell migration, and neural and vascular tissue engineering. These fields represent a great deal of the current activity in biochemical engineering across the USA. Some other interesting current areas include metabolic engineering, directed biosynthesis, signal transduction, metabolic modelling, drug design, biological membranes, bio-sensors, and biocatalysis.

A considerable, and growing amount of biomedical engineering work is now being carried out in the USA. As far as chemical engineers are concerned, their main interests are in tissue engineering, artificial organs, and drug delivery. These are carried out in collaboration with biologists and also medics who were thought to be more sympathetic to an engineering approach.

The US has a large number of bioengineering departments, training students even at the undergraduate level. However, this was not thought to be a useful degree by several senior chemical engineers with whom we talked. They considered that the prospects of employment were weak. They thought it much better to have post-graduate training in the area, and depending on whether the applications were devices, instrumentation or cell based, the mechanical, electronic or chemical engineering departments should lead the work and the training.

When asked where chemical engineers might apply their skills in the future, a senior biochemical engineer suggested some of the following:

• therapeutic proteins using rDNA
• biomaterials - tissue engineering, skin - replacements (ulcers, burns). Cartilage is thought to be the next big area. The key role for chemical engineering is in getting the design parameters worked out
• drug delivery - this is an engineering problem, there is need to design to enter the human body in the right place, and not just the preparation of a chemical. Cytosine activity, say, depends on rates of synthesis and not just concentrations
• smart materials for recognition using peptides; and the quantification of cellular biological processes
• genomics: the problem of development of high throughput screening using nanolitre volumes, and ligand/receptor models
• directed evolution and metabolic engineering offer possibilities for reactor network models to be used in cell physiology and microbial physiology. Also multiple gene manipulation.

In all of the above, the strength of chemical engineers is their quantitative approach which is directly suited to the complex and complicated interactions characteristic of biological systems.

Even in departments which have wholly embraced the new science-based chemical engineering, caution is expressed about not losing touch completely with core competencies. As we have seen above, whilst traditional chemical engineering research is tending towards either systems or molecular ideas, the undergraduates are still taught process engineering. This gives them a broader viewpoint of manufacture, but over specialisation, with its narrow view, is not good for application. The broad view of chemical engineers gives them an advantage over chemists.

This then, is at the heart of the new philosophy in the USA - a belief that chemical engineers can tackle some of the really difficult problems and move easily into areas requiring multidisciplinary skills. This belief is readily translated into research action:

What were the driving forces which brought about this shift? It was presaged in the Amundson report, which saw a move to molecular scales as essential for chemical engineering. Since then, there has been more chemistry put back into the chemical engineering curriculum after it was beginning to be lost in the early 1970's. Some think that the funding agencies may also have had a role:

Current comments about the chemical engineering community in the UK are strongly reminiscent of this statement above. Here there is considerable disquiet about the finding that UK chemical engineers have their research work cited more rarely than those in many other countries. The journals in which the US chemical engineers publish tend to have much higher impact factors (measured by standard bibliographic techniques) than do the conventional process engineering journals. It would appear that the US community has become sensitive to such bibliographic methods much earlier than the UK. By contrast, in the UK, there was some disquiet amongst heads of department at the time of the Research Assessment Exercise (RAE) about the publications of some staff in what were considered to be "fringe journals" (to chemical engineering). These fringe journals were not easily recognised as having the same importance as conventional chemical engineering journals, yet on the RAE survey they would have fared much better. Thus, in the UK, it would appear that we have had a tendency to be too conventional and conservative out of a fear of being seen to be unorthodox and weak. Ironically, we have found ourselves stigmatised as weak for following this trend.

The evidence for this is abundant: new areas of research being developed, new areas to chemical engineers being opened up, new industries not previously considered by chemical engineers became staple employment for graduates, to name a few. The benefits have not only been for chemical engineers, but also their collaborators (and employers) – the skills of scaling-up are very strong in chemical engineering, and this has helped other disciplines and industries immensely. Once the shift had been made, many considered that the benefits became obvious:

Now the groups which steered to the more applied science approach found that the move was almost autocatalytic. In one department they were able to say:

For the recruitment of staff, most departments now state that they always take the best candidate regardless of the candidates’ research field. We are forced to conclude that either there is a prejudice towards the newer product-oriented materials/molecular research, or it is difficult to recognise quality in applicants working in the more traditional chemical engineering areas. This could be due to a genuinely poorer quality or due to ‘cultural differences’ from the groups now dominating most departments. Once it became possible to get money to fund interdisciplinary research, and to persuade funding agencies that chemical engineering departments could be good at science, it became a very attractive field for new staff. This had the added benefit of generating many challenging problems, and it transpired that a chemical engineering training was highly suited to working in such areas.

There is an emphasis on building new areas of research. One way to develop new areas is to observe the general trends, and to latch onto these evolving disciplines (e.g. microelectronics, biomedical engineering, polymer physics) using the ‘toolbox’ provided by core chemical engineering. The concept of the toolbox was taken up by a biologist:

A biochemical engineer of distinction commented that he had in fact taken this concept further as the basis of his career:

Another biochemical engineer we interviewed was using genetic engineering, but didn’t see the need for collaboration with molecular biologists i.e. it was possible for a chemical engineer to learn techniques required.