Batch process

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The batch process or batch production or block mode is a batch production for example for the synthesis of chemicals . The process for the control technology is defined by DIN IEC 60050-351 as "the entirety of processes that interact with one another in a system, through which matter, energy or information is transformed, transported or stored".

"Batch process : A process that leads to the production of defined quantities of substances by subjecting quantities of input substances to an orderly sequence of process activities within a defined period of time using one or more facilities."

- ISA, IEC : ANSI / ISA-88 section 3.7

Batch Process ( English batch "stack") is a in the reaction process established term. It is used to describe processes that are processed as a "stack", that is, strictly one after the other. Batch production is a special case of discontinuous production. A quantity of material limited by the capacity of a production vessel (e.g. reactor , mixer ) is fed as a whole to the work system and removed from it as a whole after the production process has been completed. The counterpart to batch handling is a continuous process .

In the chemical industry, batch production means that the product runs through one or more reactors and remains there until the reaction has ended and the next production step can be carried out.

Schedule

Concentration curves in the batch process during the reaction phase

A typical batch process has the following timing:

  • Complete filling of the reaction vessel with the starting materials ( starting materials )
  • Reaction of the starting materials, the concentration of which is continuously falling, to form products , the concentration of which is continuously increasing. (see also stoichiometry )
  • Emptying of the reaction vessel and transferring the products to the downstream process
  • Preparation of the reaction vessel for the next filling (cleaning, maintenance)

Comparison of batch processes and continuous processes

In some applications, the batch process is used to manufacture smaller quantities of product (for example in mini plants). If possible, a continuous process is developed for large systems, as this has a higher productivity due to shorter downtimes, which would result, for example, from the necessary cleaning before the next batch process.

Guide values Batch processes continuous process
capacity low medium to high
Phase state liquid (special cases solid or gaseous) liquid and / or gaseous
temperature low high
pressure low high
product Special products Bulk products
flexibility big small

See also

  • ANSI / ISA-88 (standard for batch-oriented operation)

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