AllChemE Report: "Chemistry - Europe & the Future" - Graphical version

Energy and Processing

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• Existing Energy Supplies

• Future Energy Sources

• Chemical Process Engineering

• Analytics

• Process Intensification and Integration

Existing Energy Supplies

Energy consumption in Europe will grow, as in other parts of the world. This growth will be sustained by a combination of primary sources:

• petroleum oil, from our own continent and imported from other parts of the world
• other fossil energy sources - natural gas and coal
• nuclear energy - fission and fusion
• natural renewable resources - wind, water, direct transformation of solar radiation (photo-voltaic cells, photolysis, etc), agricultural energy (biomass in general, atmospheric, oceanographic and earth-crust temperature differences)

Chemistry research in the fossil fuel area is targetted on the search for new efficient heterogeneous (solid) catalysts for the production and refinement of vehicle and aircraft fuels. The chemical industry strives with increasing success to minimise the environmental impact and energy cost of the refining processes while maximising the energy content of the fuels produced. Heterogenous catalysts are also employed with increasing effectiveness in the conversion of exhaust gases from unavoidable combustion processes into relatively benign substances.

Chemists and chemical engineers in the nuclear industry are engaged in the manufacture of nuclear fuels, which is primarily a chemical rather than a metallurgical process. They are also involved in spent fuel reprocessing, the separation and recovery of uranium and plutonium by solution chemistry. The miniaturisation of nuclear reactors through micro-engineering and micro-chemical techniques, particularly exploiting new materials technology, will have substantial advantages for the decommissioning and decontamination of future redundant nuclear power plants. Chemists play a key role in nuclear waste monitoring, management and control.

Future Energy Sources

The development of new energy technologies will occur either because of a major change of primary energy sources which significantly affects existing technology, or because new scientific developments make energy generation or new raw materials economically and environmentally more attractive. The most probable scenario will be that of a combination of these effects causing a shift in the emphasis of the technology mix over time, in part dictated by geopolitical and economic issues. Primary sourcing is certainly not the only focus for energy research and development. Conversion from one form of energy to another will also provide an important part of the supply spectrum.

But what of these new energy sources? There is enough energy to supply society at an acceptable level from the following sources:

• The sun, our unfailing solar generator, drowns us in energy: ca. 100 megawatts per person - equivalent to the power output of a moderate-sized power station. However, the collection, conversion and distribution of this 'free' energy is a massive challenge, requiring a breakthrough in photo-voltaic cell-efficiency which can nevertheless be confidently expected. With fossil-based energy prices expected to increase rapidly due to economic and environmental pressures, these cells will become economic for more than local applications. New materials for solar cells with optimum absorbance characteristics for the solar spectrum are a particular target for chemistry.
• Non-fossil fuel sources will provide a cleaner and practically inexhaustible supply of energy. However, this will require the scientific and engineering communities to develop systems of high reliability and lower risk and the education of the public to accept that the benefits outweigh any remaining minimal risk. The conversion of wind, water, earth-crustal, oceanographic and atmospheric temperature differences to electricity, particularly for local uses, is already in progress and has relatively little direct interaction with chemistry. Farming of agricultural biomass could provide an additional source of carbon-based fuel for the next century, but while its great advantage is that nature assembles the desired carbon skeleton in the organic fuel components, the disadvantage is the low energy conversion efficiency and the low availability of water in arid areas. For such parts of our planet, however, solar radiation is at a maximum. It does not seem likely, however, that bio-derived energy could ever provide a significant proportion of mankind's energy requirements.
• For transportation, conversion to a form of energy with high energy content per unit weight, little risk and easy logistics in distribution, filling and use is essential. At present and in the foreseeable future, this energy will be in liquid form, especially for long-range and heavy-duty traffic, but for local and low-duty traffic the electric vehicle has a bright future (see Caring for our planet). Photolysis of water by catalytic means may well lead to the construction of vast plants for automotive fuel production. The hydrogen-based economy is a possibility, certainly for electricity production, although for automotive purposes the problem of the heavy weight of hydrogen carriers must be overcome. However, the use of metal hydrides as storage media may provide a solution.
• While petroleum may become relatively inaccessible or too precious to be used in energy production, conversion of coal to mixtures of carbon monoxide and hydrogen (Syngas) and thence to liquid fuel for the automotive sector will provide solutions to transportation in the medium term. Hybrid forms of energy such as hydrocarbons from coal liquefied with hydrogen, perhaps under photolytic conditions, may be used as energy sources. While known technology invented by Fischer and Tropsh can provide, with improvements in efficiency, existing transportation gasolines, the preferred and cleaner fuels will be methanol and dimethyl ether consumed to create energy in fuel cells. The tandem use of such fuel cells with low-load batteries may provide a medium-term solution to the needs of short-distance transportation in cities (see Caring for our planet). The storage of energy may also be achieved by chemical means, using simple benign materials such as as methanol (a source of carbon monoxide and/or hydrogen) and methylcyclohexane (a store of hydrogen).

Chemical Process Engineering

Chemical engineers are people who turn chemists' ideas into products. Engineering is an independent science with developed concepts for new process routes.

The operation and management of chemical manufacturing plants and processes have been transformed in the last 30 years by computing technology. Computer power and speed have increased so much that real-time dynamic process simulation has become possible and, in turn, advanced feed-forward control has also become practicable.

The operation of chemical processes generates large amounts of information, only some of which is easily accessible at the moment. However, modern software technology, including large-scale networking (for example via the Internet), is starting to provide techniques for capturing, systematising, relating, accessing and presenting this information in a manageable form. This will have a powerful impact on the design, control and optimisation of chemical processes, in particular through greatly enhanced computer modelling techniques.

Novel mathematical techniques (fuzzy logic, genetic algorithms and neural networks) make possible the development of sophisticated new modelling and process control systems. In neural networks, sensor signals are introduced and weighted in an intricate layered system, more or less as neurones are believed to work in the human brain. Such a system can be made to be self-learning, can be very fast and would not require complex hardware. However, neural networks will not be used where operational safety might be put at risk, but will be used in conjunction with orthodox feed-forward control backed up by emergency shut-down systems.

The combination of process understanding, improved analysis, cheap, powerful computers and advanced software will transform our insights into operating processes with consequent economic and technical benefits. The concept of automatically self-regulating chemical plants is not far from reality.

Analytics

Traditionally, the monitoring of quality and purity control in chemical manufacturing has been achieved by the analysis of samples removed at various points in the process cycle, interpretation of the data obtained and feedback to the plant managers, who can then alter the plant operating conditions. This is time-consuming and inefficient. The in situ analysis of processing conditions in real-time, through incorporation of sensors linked to computers within a neural network, closes the loop in plant management and control procedures and will significantly improve efficiency.

Arrays of sensors can monitor, for example, temperature, pressure, flow rates and residence times in reactors. These sensors will be based on a variety of techniques using various regions of the electromagnetic spectrum. The content of gases and liquids can be monitored by ultra-fast chromatography. The separation techniques necessary to help this may require new porous membrane technology. Electrochemical techniques will be used increasingly to monitor dissolved substances which carry electrical charges.

Process Intensification and Integration

A better understanding of processes will enable us to develop radically new approaches to the manufacture of chemicals, for example by combining several unit operations into one or bringing product manufacture to the point of sale.

Today's chemical plants are easily recognisable. Their architecture is based on distillation columns, reaction vessels, filters and mixers, whose operational principles were already known in the 1950s. However, recent research in chemical engineering has greatly improved understanding of the basic chemistry and physics of processing. This is stimulating the design of new types of equipment which will not only be more efficient but less obtrusive.

For instance, coupling chemical reaction with separation or heat transfer has led to the concept of multi-functional reactors with increased yield. Examples are reactive distillation and reactive extraction, where advantages of the separation techniques are used for the design of the reaction process. In general, process integration leads to savings in energy consumption and raw materials. Conversely, decoupling may be beneficial. Instead of using one single tank to carry out a precipitation where the flow pattern is complex and difficult to control, a precipitator where nucleation is to be decoupled from particle growth and agglomeration could lead to significant improvements in the product's quality. Processes which involve rapid changes in the physical properties of the reactants, for example major changes in viscosity, can benefit from the design of specialised equipment.

A challenging possibility which integration and intensification raises is the movement of the manufacture of certain chemicals from large centralised sites to small manufacturing units at the point of consumption. This approach does not challenge the concept of economy of scale, but rather shifts it from the amount of product manufactured to the number of plants manufacturing it. Full process design will precede plant design, and environmental protection will be an integral part of the production process. Emissions to the environment from both deliberate and accidental sources will be minimised. Processes of the future will generate few leaks and little waste. The amount of water, air and solvents used in chemical processing will be reduced to a minimum. As far as possible, production of hazardous intermediates will be suppressed and effluent recycled. The treatment of wastes will take place in the plant itself, resulting in the necessity to treat smaller amounts of effluent containing higher concentrations of contaminants. Analytics will allow products to be monitored until recycled or destroyed. Intrinsic safety will be improved by handling and storing smaller volumes of materials and using smaller reactors.