Modular process applications

In the following, the concept of micro modular process engineering is introduced together with the backbone interface developed in order to realize this modular approach. The integration of sensors and an electronic bus system is also described, and the physical characterization of the backbone is discussed within a case study of the enantioselective synthesis of organoboranes. Within the second case study, the sulfonation of toluene with gaseous sulfur tri oxide, the backbone system together with the micro structured devices used is finally assessed based on its application to chemical synthesis. 

The process model was built using PETROX, a proprietary sequential-modular process simulator from PETROBRAS. The simulation comprises 53 components and pseudocomponents and 64 unit operation modules, including 7 distillation columns and a recycle stream. All modules are built with rigorous, first-principles models. For optimization applications, PETROX was linked to NPSOL, an SQP optimisation algorithm. 

Application The Borstar polypropylene (PP) process can produce homopolymers, random copolymers, heterophasic copolymers, and very high-rubber-content heterophasic copolymers. It is a modular process consisting of a loop reactor/gas-phase reactor combination. 

Frenkel [5] classifies raw water supplies into several types with different characteristics (Table 12.1). Other authors propose similar classifications and often add hardness to the list of characteristics. Arden and Forrest [6] take a modular proach to treatment. Silted river water, for example, considered suitable only for irrigation, is improved by sedimentation to a quality comparable to that of most other surface waters. The clarified water then becomes suitable for crude industrial applications. Coagulation and filtration then virtually eliminate suspended solids and make the water suitable for general purposes. These include plant utility use without necessarily qualifying the water for process application. Beyond this point, the intended application determines the extent of treatment required. 

With photocatalysis the main problems encountered in the previously examined applications of PVRs are avoided. It is also worth noting that (i) the coupling of photocatalysis with the pervaporation process allows for a complementary exploitation of the solar spectrum. In fact, photocatalysis is normally only able to use its ultraviolet component, while the remaining thermal part of the spectrum can be utilized to heat the fluid and to evaporate the permeate (ii) photocatalysis and pervaporation have common operative conditions liquid solutions (often aqueous solutions), low concentrations of the reactants and consequently of the products, low temperature and atmospheric pressure and (iii) once the type of light source is chosen, photocatalysis is a modular process like pervaporation. Therefore the integration of the two processes is straightforward and advantageous. 

Recently, multistep enzyme-catalyzed reactions have attracted the attention of chemists and biotechnologists, as they can be combined in a modular manner and often lead to high-value compounds. All naturally occurring metabolic pathways are basically cascade reactions. Based on natural principles, synthetic chemists search for universal multistep processes applicable to a vast number of chemical compounds. Multistep enzyme-catalyzed reactions involving nonphysiological substrates and selective enzymes are of particular interest because they may lead to tailor-made complex molecules with desired properties. Moreover, one of the most important advantages of multistep enzyme-catalyzed reaction sequences... 

Raytek (Fluke) CS-100, GS-lOO, TF-100, TIP-450 (all using the MP-50 Thermalert line scanner) Optomechanically scanned each system for a different process application, modular thermoelectrically cooled, high-resolution analog and digital outputs various wavelengths operate with integral control system or host computer. 

Due to the modularity and availability of a number of functional elements, multistep reactions can be set up, studied, optimized, and combined with separation techniques. A number of process applications have been described by industrial and university laboratories, for example, the investigation of organic textbook reactions [27], the Moffatt-Swem oxidation [28], Dibal-H reduction [29], phase transfer catalysis [30], and gas/liquid separation techniques such as desorption [31] as well as liquid/liquid separation by a hydrocyclone [32], Technical details of the MMRS can be found elsewhere and will not be described in more detail here [26]. 

Die Fabrik auf dem Chip, Spektrum der Wissenschafi, October 2002 Miniaturization and modularization of parts of future chemical apparatus general advantages of micro flow expert opinions specialty and fine chemical applications leading position of German technology flexible manufacture large-capacity micro reactors reformers for small-capacity applications compatible and automated micro-reaction systems process-control systems temperature and pressure sensors [209]. 

Applications Membranes create a boundary between different bulk gas or hquid mixtures. Different solutes and solvents flow through membranes at different rates. This enables the use of membranes in separation processes. Membrane processes can be operated at moderate temperatures for sensitive components (e.g., food, pharmaceuticals). Membrane processes also tend to have low relative capital and energy costs. Their modular format permits rehable scale-up and operation. This unit operation has seen widespread commercial adoption since the 1960s for component enrichment, depletion, or equilibration. Estimates of annual membrane module sales in 2005 are shown in Table 20-16. Applications of membranes for diagnostic and bench-scale use are not included. Natural biological systems widely employ membranes to isolate cells, organs, and nuclei. 

Large-scale ultrasonic irradiation is extant technology. Liquid processing rates of 200 liters/minute are routinely accessible from a variety of modular, in-line designs with acoustic power of several kW per unit (83). The industrial uses of these units include (1) degassing of liquids, (2) dispersion of solids into liquids, (3) emulsification of immiscible liquids, and (4) large-scale cell disruption (74). While these units are of limited use for most laboratory research, they are of potential importance in eventual industrial application of sonochemical reactions. 

Stainless steel is the material of choice for process chemistry. Consequently, stainless steel microreactors have been developed that include complete reactor process plants and modular systems. Reactor configurations have been tailored from a set of micromixers, heat exchangers, and tube reactors. The dimensions of these reactor systems are generally larger than those of glass and silicon reactors. These meso-scale reactors are primarily of interest for pilot-plant and fine-chemical applications, but are rather large for synthetic laboratories interested in reaction screening. The commercially available CYTOS Lab system (CPC 2007), offers reactor sizes with an internal volume of 1.1 ml and 0.1 ml, and modular microreactor systems (internal reactor volumes 0.5 ml to... 

The older modular simulation mode, on the other hand, is more common in commerical applications. Here process equations are organized within their particular unit operation. Solution methods that apply to a particular unit operation solve the unit model and pass the resulting stream information to the next unit. Thus, the unit operation represents a procedure or module in the overall flowsheet calculation. These calculations continue from unit to unit, with recycle streams in the process updated and converged with new unit information. Consequently, the flow of information in the simulation systems is often analogous to the flow of material in the actual process. Unlike equation-oriented simulators, modular simulators solve smaller sets of equations, and the solution procedure can be tailored for the particular unit operation. However, because the equations are embedded within procedures, it becomes difficult to provide problem specifications where the information flow does not parallel that of the flowsheet. The earliest modular simulators (the sequential modular type) accommodated these specifications, as well as complex recycle loops, through inefficient iterative procedures. The more recent simultaneous modular simulators now have efficient convergence capabilities for handling multiple recycles and nonconventional problem specifications in a coordinated manner. 

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