Chemical engineering process scale

If one draws an analogy of the scale-up from a laboratory chemical engineering process to a chemical plant to the scale-up of a mouse to a human, one finds that both situations are governed by a great number of... 

In only a few cases can theoretical analysis alone provide full description of chemical engineering process units. Normally it is necessary to turn to experimental work, often upon small- or pilot-scale models, to complete such a study. Even if a complete quantitative theory is available, experimental results are still necessary to verify it, since theories are invariably based on assumptions that may not be completely satisfied in the real systems. 

The establishment of a nuclear power industry based on fission reactors involves the production of a number of materials that have only recently acquired commercial importance, notably uranium, thorium, zirconium, and heavy water, and on the operation of a number of novel chemical engineering processes, inciuding isotope separation, separation of metals by solvent extraction, and the separation and purification of intensely radioactive materials on a large scale. This text is concerned primarily with methods for producing the special materials used in nuclear fission reactors and with processes for separating isotopes and reclaiming radioactive fuel discharged from nuclear reactors. 

Ouni, T., Honkela, M., Kolah, A., Aittamaa, J. (2006). Isobutene dimerisation in a miniplant-scale reactor. Chemical Engineering Process Journal, 45, 329—339. 

Most chemical engineering processes involve complex multiphase fluid systems, and their evolution depends on the mechanism by which the inhomogeneous subsystems exchange information at different length scales. Whereas numerous theoretical methods with specific description accuracies have been developed for investigating physicochemical properties of various fluid systems, a unified theory that enables the investigation of mesoscale problems is still needed. Here, we introduce a unified... 

Mechanistic studies provide the fundamental foundation required to develop a comprehension of the critical parameters for an ATRP. ° The studies generated the knowledge required to develop more environmentally benign ATRP procedures ° ° and remain crucial to any future developments in ATRP, since they generate the kinetic data that provide the underpinnings for chemical engineers to scale up the processes to industrial-scale production of specialty materials. 

Specific heat data can be of value in its own right since this information is required by chemists and chemical engineers when scaling up reactions or production processes, it provides information for mathematical models, and is required for accurate kinetic and other advanced calculations. It can also help with curve interpretation since the slope of the curve is fixed and absolute, and small exothermic or endothermic events identified. Overall, it gives more information than the heat flow trace because values are absolute, but it does take more time, something often in short supply in industry. 

The scientific basis of extractive metallurgy is inorganic physical chemistry, mainly chemical thermodynamics and kinetics (see Thermodynamic properties). Metallurgical engineering reties on basic chemical engineering science, material and energy balances, and heat and mass transport. Metallurgical systems, however, are often complex. Scale-up from the bench to the commercial plant is more difficult than for other chemical processes. 

Scale- Up of Electrochemical Reactors. The intermediate scale of the pilot plant is frequendy used in the scale-up of an electrochemical reactor or process to full scale. Dimensional analysis (qv) has been used in chemical engineering scale-up to simplify and generalize a multivariant system, and may be appHed to electrochemical systems, but has shown limitations. It is best used in conjunction with mathematical models. Scale-up often involves seeking a few critical parameters. Eor electrochemical cells, these parameters are generally current distribution and cell resistance. The characteristics of electrolytic process scale-up have been described (63—65). 

Tuma, L. and C. Bagner 1998. Assurance of Safe Pilot Plant Scale-Up of Chemical Processes, in (G. A. Melhem and H. G. Fisher, eds.). International Symposium on Runaway Reactions, Pressure Relief Design, and Effluent Handling, American Institute of Chemical Engineers, New York. 

The principal technological changes in the engineering control of air pollution were the perfection of the motor-driven fan, which allowed large-scale gas-treating systems to be built the invention of the electrostatic precipitator, which made particulate control in many processes feasible and the development of a chemical engineering capability for the design of process equipment, which made the control of gas and vapor effluents feasible. 

The chemical engineer is concerned with the industrial application of processes. This involves the chemical and microbiological conversion of material with the transport of mass, heat and momentum. These processes are scale-dependent (i.e., they may behave differently in small and large-scale systems) and include heterogeneous chemical reactions and most unit operations. Tlie heterogeneous chemical reactions (liquid-liquid, liquid-gas, liquid-solid, gas-solid, solid-solid) generate or consume a considerable amount of heat. However, the course of... 

As the flow of a reacting fluid through a reactor is a very complex process, idealized chemical engineering models are useful in simplifying the interaction of the flow pattern with the chemical reaction. These interactions take place on different scales, ranging from the macroscopic scale (macromixing) to the microscopic scale (micromixing). 

Sie, S.T. and Krishna, R., 1998. Process development and scale-up 1. Process development strategy and methodology. Reviews in Chemical Engineering, 14, 46-87. 

N. Maddison, Explosion Hazards in Large Scale Purification by Metal Dust, Hazards XII—European Advances in Process Safety, Symposium Series No. 134, Institution of Chemical Engineers, Rugby, UK, 1994. 

Nitric acid is one of the three major acids of the modem chemical industiy and has been known as a corrosive solvent for metals since alchemical times in the thirteenth centuiy. " " It is now invariably made by the catalytic oxidation of ammonia under conditions which promote the formation of NO rather than the thermodynamically more favoured products N2 or N2O (p. 423). The NO is then further oxidized to NO2 and the gases absorbed in water to yield a concentrated aqueous solution of the acid. The vast scale of production requires the optimization of all the reaction conditions and present-day operations are based on the intricate interaction of fundamental thermodynamics, modem catalyst technology, advanced reactor design, and chemical engineering aspects of process control (see Panel). Production in the USA alone now exceeds 7 million tonnes annually, of which the greater part is used to produce nitrates for fertilizers, explosives and other purposes (see Panel). 

Oldshue, J. Y, F luid Mixing, Heat Transfer and Scale Up, Chemical and Process Engineering, April 1966, p. 183. 

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