THE ROLE OF PROCESS INTENSIFICATION IN CUTTING GREENHOUSE GAS EMISSIONS
Between 1900 and 1955 the average rate of global energy use rose from about 1 TW to 2 TW. Between 1955 and 1999 energy use rose from 2 TW to about 12 TW, and to 2006 a further 16% growth in primary energy use was recorded world-wide. There are recommendations by the UK Royal Commission on Environmental Pollution, subsequently supported by others in the UK, that we need to reduce CO2 emissions by over 50% in order to stabilise their impact on global warming, (CO2 being the principal gas believed to be contributing to this phenomenon). One way in which we can address this is by judicious use of process intensification technology.
Process intensification may be defined as: "Any engineering development that leads to a substantially smaller, cleaner, safer and more energy efficient technology." It is most often characterised by a huge reduction in plant volume - orders of magnitude - but its contribution to reducing greenhouse gas emissions is also substantial.
Potential energy savings due to investment in process intensification were studied by a leading process integration company in the mid 1990s, to assist the UK Government in formulating a strategy on intensification. Overall plant intensification was been identified as having a technical potential of 40 PJ/year, (about 1 million tonnes of oil equivalent/a). The total potential energy savings due to investment in process intensification in a range of process unit operations were estimated to be over 74 PJ/year, (1 PJ = 1015J).
Process intensification offers a number of opportunities to improve energy efficiency and reduce environmental impact. Many chemical reactions which are currently carried out as batch processes in stirred tanks, could be carried out in continuously operated, intensified reactors such as spinning disc or oscillatory baffle types. The plant used for separations can be made highly compact, while terms such as the 'pocket-sized nitric acid plant' are becoming the norm.
This paper will relate by example process intensification to the main themes of the Conference, and identify the challenges that process intensification is meeting across a range of sectors of industry and commerce.
Professor David Reay, M.Sc., C.Eng., M.R.Ae.S.
A Visiting Professor at Brunel University (School of Engineering & Design), a Special Professor at Nottingham University, England (School of the Built Environment) and Visiting Professor at Heriot-Watt University. Edinburgh, Scotland (School of Engineering & Physical Sciences) where he teaches process intensification. A Consulting Engineer in energy-related fields. He graduated in Aeronautical Engineering from Bristol University. As Principal Consultant of David Reay & Associates, he specialises in compact heat exchangers, process intensification, and novel unit operations. He is also active in heat recovery and heat pump technology, and has an interest in human thermoregulation and 'local' thermal management.
He is currently managing the IEA Heat Pump Annex 33 on compact heat exchangers, and has recently completed, with AEA Energy & Environment a strategy document for the Carbon Trust to target process heat recovery, intensification and integration for carbon emission reductions. He has written or edited 7 energy-related books and is Editor-in-Chief and European Editor of Applied Thermal Engineering, which has regularly featured Special Issues on PRES Conferences. For 12 years he advised the European Commission on energy R&D, introducing process intensification into the JOULE programme, and is Past President of the UK Heat Transfer Society and Honorary Life Member of the Heat Pump Association.