(240a) Agro-, Bio-, Chemical- and Energy Conversion - Process Intensifications and Their Applications in Intensified Integrated Plants and Engineered Ecosystems

Process Intensification (PI) initially emerged as a novel process design philosophy in which the processing volume was deliberately reduced while the processing fields were enhanced in order to achieve the same levels of production rate. The resulting processes have lower capital and operating costs and in some cases novel products are obtained. PI is principally driven by the enhancement and control of momentum, heat and mass transfer and catalytic processes which in turn imply dependence on advances in materials science and fabrication technology for reactors. Further enhancement in PI is achieved through the synergistic superimposition of several processing fields within a reactor, integration of intensified unit processes within a production platform (plant), facilitating multi-component interactions especially in biological systems and sensing and controlling of the processes. This incorporation of these process conditions within a reactor require a new approach to reactor and process design philosophy which, nevertheless, also provides novel processes with a smaller number of steps, higher energy and conversion efficiencies and high selectivity as well as novel products.

We can assume that such intensified integrated plants which have been well analysed, already exist in the form of the human body. The mimicking of the human body in vitro (tissue engineering and biomedical engineering) does also help to understand the biological processes of the human body while providing a model for intensified reactors through which generic BioProcesses Intensification has been recently achieved, with intensification levels of ca. 10-100 fold compared with present technology. Furthermore, in chemical processes, the inherent restrictions of bioprocesses do not apply and hence the human body model of chemical plants will have higher degrees of freedom, only restricted by the availability of support technologies such as materials, sensors and control systems.

The human body can also be used for Energy (conversion)-PI deviating significantly from the well established conversion processes. Here the principle target is the establishment of Intensified Integrated Bio-refineries (IIBR) based on the conversion of biomass to power and chemicals where the process is integrated with agriculture. Such generators need to be distributed plants due to the distributed nature of the biomass feedstock. Intensified unit processes in IIBR include combustion, separation, syngas-to-power/fuel conversion and gas and process water clean-up.

Although we propose that the human body and vital organs can be a model for intensified integrated Biochemical or Chemical plants and unit processes, nature's processing strategy is not always intensified. This is particularly true and equally very important in agriculture. Hence the application of the PI- principles, now commonly accepted in Chemical-PI, can enhance output from ecosystems in terms of plant/crop growth and maintenance. This is particularly important in cultivation in marginal land under water and nutrient stress. It is also possible to intensify plant nitrogen fixation from air thus reducing fertilizer demand. Such methods can be deemed to be Agro-Process Intensification which can open new fields for main stream chemical engineering leading to engineered ecosystems. Observed current level of intensification is ca. 3 fold, far in excess of that achieved by genetic modification.

In this review, after a summary of nature's processing strategy in the human body and plant/crop growth, recent examples of Agro- Bio- Chemical and Energy-Process Intensifications will be given. Advances in materials science (especially in nano-structured macro-porous materials and catalysts) relevant to PI will be summarised with examples. Performance and cost data of a recent integrated intensified energy plant will be provided to illustrate the benefits of intensified-integrated plants.