Batch process general recipe

Emulsion Polymerization A typical recipe is give in Table I. Emulsion polymerization was carried out at 60°C under a nitrogen atmosphere using a batch process. Theoretical solids content in all the formulations was 25%, and generally the conversions were better than 98%. A polyvinyl acetate homopolymer and two poly (vinyl acetate-butyl acrylate) copolymers having VA/BA composition of 85/15 and 70/30 were prepared according to the above procedure. 

A particular confectionery industry problem is the long product life. A long-established product, initially made by a batch process, must retain the same qualities when prepared by a more modern continuous plant process, and a great deal of work can go into making the two products exactly the same. In general, however, the continuous plants are more effective at heating the product and produce less sucrose inversion, although, even after the recipe has been adjusted to account for this, textural differences sometimes persist. 

The production of high-value-added products (pharmaceutical active principles, agrochemicals, etc.) has stimulated investigations on batch processes for several decades. Generally, a batch plant can manufacture several products sharing standard equipment in a series of production campaigns, with the ability to adapt itself to variations of raw materials and to rapid market flucmations. A batch process involves discrete tasks embedded in an interconnected predefined sequence from raw materials to final products. The predefined sequence is commonly known as a recipe. The recipe consists of the amount of raw materials that are necessary to be involved in the individual tasks as well as their durations. It also includes the operating conditions of the tasks as well as additional constraints of the process (safety features for instance). 

General and site recipes are non-equipment dependent and describe the technique of the process, or how to do it in principle, they may however, specify when known, data that may be required for the equipment, for example, pressure requirements. The general recipe is defined at the level of the enterprise, whilst the site recipe is specific to a particular site. Master and control recipes describe the task, i.e. how to do it with actual resources. The master recipe is the required recipe as without it no control recipe can be created and therefore no batches can be produced. 

The term recipe has a range of definitions in batch processing, but in general a recipe is a procedure with the set of data, operations, and control steps required to manufacture a particular grade of product. A formula is the list of recipe parameters, which includes the raw materials, processing parameters, and product outputs. A recipe procedure has operations for both normal and abnormal conditions. Each operation contains resource requests for certain ingredients (and their amounts). The operations in the recipe can adjust set points and turn equipment on and off. The complete production run for a specific recipe is called a campaign (multiple batches). 

The next two steps after the development of a mathematical process model and before its implementation to "real life" applications, are to handle the numerical solution of the model s ode s and to estimate some unknown parameters. The computer program which handles the numerical solution of the present model has been written in a very general way. After inputing concentrations, flowrate data and reaction operating conditions, the user has the options to select from a variety of different modes of reactor operation (batch, semi-batch, single continuous, continuous train, CSTR-tube) or reactor startup conditions (seeded, unseeded, full or half-full of water or emulsion recipe and empty). Then, IMSL subroutine DCEAR handles the numerical integration of the ode s. Parameter estimation of the only two unknown parameters e and Dw has been described and is further discussed in (32). 

Most commercicil continuous systems for emulsion polymerization consist of a series of CSTR s in which all the recipe ingredients enter the first reactor and the product latex is removed from the last reactor. The individual reactors in the train are generally quite similar to the reactors employed for batch and semi-batch polymerizations. In fact some of the early continuous processes were constructed by installing piping between batch reactors. 

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