Ind. Eng. Chem. Res. 2007, 46, 3465-3485 3465 COMMENTARIES Modern Chemical Engineering in the Framework of Globalization, Sustainability, and Technical Innovation† 1. Introduction: Chemical and Related Process according to technical specifications, but rather according to IndustriessAt the Heart of a Great Number of Scientific quality features, such as size, shape, color, aesthetics, chemical and Technological Challenges and biological stability, degradability, therapeutic activity, solubility, mechanical, rheological, electrical, thermal, optical, Chemical and related industries, including process industries magnetic characteristics for solids and solid particles, touch, such as petroleum, pharmaceutical and health, agriculture and handling, cohesion, friability, rugosity, taste, succulence, and food, environment, textile, iron and steel, bituminous, building sensory properties. This control of the end-use property, materials, glass, surfactants, cosmetics and perfume, and expertise in the design of the process, continual adjustments to electronics, are evolving considerably at the beginning of this meet the changing demands, and speed in reacting to market new century, because of unprecedented market demands and conditions are the dominant elements. Indeed, these high-margin constraints stemming from public concern over environmental products, which involve customer-designed and perceived and safety issues, and sustainable considerations. formulations, require new plants, which are no longer optimized To respond to these demands, the following challenges are to produce one product at good quality and low cost. Actually, faced by the chemical and process industries, involving complex the client buys the product that is the most efficient and the systems both at the process scale and at the product scale. first on the market. He will have to pay high prices and expect (a) For the production of commodity and intermediate a large benefit from these short-lifetime and high-margin products such ammonia, sulfuric acid, calcium carbonate, products. Moreover, the need is for multipurpose systems that ethylene, methanol, and ethanol, patents usually do not concern can be easily cleaned and easily switched over to other recipes the products, but rather the processes. And now, these processes (flexible production, small batches modular setups, etc.). are not selected based on economic exploitation alone. Rather, It is important to note that, today, 60% of all products sold the compensation resulting from the increased selectivity and by chemical companies are crystalline, polymeric, or amorphous savings linked to the process itself must be considered. With solids. These complex materials must have a clearly defined high bulk chemicals, the problem becomes complex, because physical shape to meet the designed and desired quality other factors, such as health, safety, and environmental aspects standards. This also applies to pastelike and emulsified products. (including nonpolluting technologies, reduction of raw materials Actual developments require increasingly specialized materials, and energy losses, and product/byproduct recyclability), must active compounds, and special effect chemicals, which are much be considered. The trend toward global-scale facilities soon will more complex, in terms of molecular structure, than traditional, require a total or partial change of technology: facilities will industrial high-bulk-volume chemicals. no longer be capable of being built “just a bit bigger” if one must handle throughputs never before seen in chemical and The aforementioned considerations must be taken into account related industries. Therefore, we are faced with the need for a in the modern chemical engineering of today. But how? We change in technologies to scale-up the reliability of new shall try to answer this question in presenting, successively, the processes from the current semi-work scale to a vast scale in current complementary approach for chemical engineering, which there is no previous experience. Thus, for such high- which involves the organization of scales and complexity levels, volume bulk chemicals, the client will buy innovative processes then the current tools for the success of this approach, and the that are nonpolluting and perfectly safe, which might involve four parallel tracks met for investigations in the topic. membrane technologies and/or microtechnologies that are concerned with microstructured mixers or reactors. 2. Today’s Chemical and Process Engineering Approach: (b) Progression from traditional intermediate chemistry to new Organizing Scales and Complexity Levels specialities, active material chemistry, and related industries Thus, chemical and process engineering is concerned with involves the chemistry/biology interface of the agriculture, food, understanding and developing systematic procedures for the and health industries. Similarly, it involves the upgrading and design and optimal operation of chemical, pharmaceutical, food, conversion of petroleum feedstocks and intermediates and the cosmetics, and process systems, ranging from nanosystems and conversion of coal-derived chemicals or synthesis gas into fuels, microsystems to industrial-scale continuous and batch processes, hydrocarbons, or oxygenates. This progression is driven by the all within the concept of the chemical supply chain.1 new market objectives, where sales and competitiveness are dominated by the end-use properties of a product, as well as its This chain begins with chemical or other products that quality. Indeed, end consumers generally do not judge products industry must synthesize and characterize at the molecular level. The molecules are then aggregated into clusters, particles, or thin films. These single or multiphase systems form microscopic * Tel.: +33(0)3 83 17 50 77. Fax: +33 (0)3 83 32 73 08. E-mail: [email protected]. mixtures of solid, pastelike, or emulsion products. The transition † This paper was originally scheduled to be part of the special issue, from chemistry and biology to engineering involves the design “Membrane Engineering for Process Intensification” (Vol. 46, No. 8). and analysis of production units, which are integrated into a 10.1021/ie061290g CCC: $37.00 © 2007 American Chemical Society Published on Web 04/26/2007 3466 Ind. Eng. Chem. Res., Vol. 46, No. 11, 2007 Figure 1. Scales and complexity levels in process engineering. (Reprinted with permission from ref 8; copyright Berkeley Electronic Press, 2003.) process and become part of a multiprocess industrial site. Moreover, any progress in the analysis of multiscale structures Finally, this site is part of the commercial enterprise driven by in chemical engineering, not to mention any breakthrough in market considerations and demands the inclusion of the product understanding complex systems, is bound to contribute to the quality, once again, within the framework of sustainability. formation of a new knowledge base for the process industry, In this supply chain, it should be emphasized that product which requires a complex system and multiscale methodology.3 quality is determined at the nanoscale and microscale levels This multiscale approach is also encountered in biotechnology and that a product with a desired property must be investigated and bioprocess engineering, to better understand and control for both structure and function. This will help make the leap biological tools such as enzymes and microorganisms and to from the nanoscale level to the process level. The key to success manufacture products. In such cases, it is necessary to organize is to obtain the desired end-use properties, and then to control the levels of increasing complexity from the gene with known product quality, by controlling the microstructure formation. A properties and structure, up to the product-process couple, by thorough understanding of the structure/property relationship modeling coupled mechanisms and processes that occur on at both the molecular level (e.g., surface physics and chemistry) different scales, as shown in Figure 2. This concerns approaches and the microscopic level (e.g., coupling reaction mechanisms on the nanoscale (molecular and genomic processes, and and fluid mechanics) is of primary importance to be able to metabolic transformations), the microscale (respectively, en- design production processes that ensure the customer quality zymes in integrated enzymatic systems, biocatalyst environment, requirements. Moreover, most of chemical processes are non- and active aggregates), the mesoscale for unit operation (bio- linear and nonequilibrium, belonging to the so-called complex reactors, fermenters, exchangers, separators, etc.), and macro- systems for which multiscale structure is the common nature. scales and megascales (respectively, for units and plants, and This requires an integrated system approach for a multidis- for the interaction with the biosphere). ciplinary and multiscale modeling of complex, simultaneous, For illustration, biology’s catalysts, enzymes, are protein and often coupled momentum-, heat-, and mass-transfer phe- molecules that substantially accelerate the biochemical reaction nomena and kinetic processes that are happening on different in the cell. Understanding an enzyme at the molecular nanolevel scales: means that it may be tailored to produce a particular end-product (1) Different time scales (10-15 to 108 s) are used, from at the product and process mesoscales and macroscales. This femtoseconds