Batch process campaign

Campaign processes have also variable production time. Different to continuous production, campaign production is related to multi-purpose assets, where different processes and products can run on the same production resource and change-over decisions between campaigns need to be taken. Finally, batch processes have a defined lot size, start and end time of production as well as throughput. 

Mujtaba and Macchietto (1994) presented an industrial case study in which dynamic optimisation method of Mujtaba and Macchietto (1993) is utilised for the development of the optimal operation of an entire batch distillation campaign where 100 batches of fresh charge have to be processed with secondary reprocessing of intermediate off-cuts. The process involved a complex separation of a five-component mixture of industrial interest, described using non-ideal thermodynamic models. In addition, the operation of the whole production campaign was subject to a number of resource constraints, for example -... 

Evaporators can be designed to operate batchwise, continuously or in a semi-batch or campaign fashion, but once an evaporator system is designed to operate in one of these modes, it is not easy to change from one type of operation to another from the standpoint of available hardware and process instrumentation. 

Grunow, M., Gunther, H.-O., and Lehmann, M. Campaign planning for multi-stage batch processes in the chemical industry. OR Spectrum, 24(3) 281-314, 2002. 

Contamination of steam condensate can occur by leaks in heat exchangers. When steam is shut off at the end of a batch or campaign, a vacuum forms in the steam space. This vacuum can suck solvent through a leak from the process side of the exchanger. When next steam is turned on, solvent is pushed through the steam trap to the hot well. 

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). 

As discussed earlier, productions in the FCPI are commonly managed in so-called production campaigns that rely mainly on batch or semi-batch processes 13]. Roberge et al. of Lonza Visp (Switzerland) 5] investigated the benefits and drawbacks of microreaction technology in the FCPI to learn more about this alternative technique. Their results are discussed in the following section. 

The continuous process developed in the laboratory proved to be a scalable process in the pilot plant. The trickle bed oxidation reactor was scaled by numbering up. Laboratory operating parameters were replicated for each oxidation column operated in parallel. Heat and mass transfer characteristics were identical in each oxidation column. Steady-state operation was demonstrated in the pilot plant for over 50 h. Three continuous reactors were operated in succession for production of a stable quenched product solution. Over 100 kg of API was produced during the pilot plant campaign using this setup. Also, the quality of the product produced by the continuous process was comparable to that of the batch process. 

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). 

Subcase bl This case is encountered, for example, when batch records from different production campaigns are compared and the same number of samples was analyzed in each campaign. (Note under GMP, trend analysis has to be performed regularly to stop a process from slowly, over many batches, drifting into a situation where each parameter on its own is within specifications, but collectively there is the risk of sudden, global loss of control. Catastrophe theory has gained a foothold in physical and biological literature to describe such situations cf. Section 4.14.)... 

Three different batch sizes were used, namely =400, =800, respectively =1200 kg in the chemical industry it is standard practice to validate a process for the available kettles and then adjust the particular batch size (minimum filling so the stirrer bar remains covered, maximum filling so no overpressure occurs and vents stay free) to achieve the requested tonnage often, campaigns of batches are run before the equipment is cleaned and refitted for the next product, see batch numbers 19. .. 23, followed by 1,. ... ... 

Finally, in multipurpose plants compounds, which can be deposited in various places (e.g. corners, zones near sealings) in equipment, can contaminate products of the subsequent batch. Therefore, all equipment must be thoroughly cleaned before the next production campaign starts. Contaminants can be formed in the process, sometimes at ppm level, and be recycled with streams of solvents and/or reactants. Hence, the influence of recycling on process performance indices must be included in the program of laboratory studies, at least in their final stage. 

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