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Many new chemical, particularly batch operations, can be scaled up directly from the bench to the plant by developing the process and performing lab testing with the scaleup in mind.
MANY COSTLY AND TIME-CONSUMING startup problems can be avoided if key scaleup issues are understood and resolved during the development of a new chemical process. Processes are often scaled up in stages from the lab to the pilot plant or semi-works scale to obtain engineering data for commercial plant design. However, this staged scaleup strategy is not always practical for specialty chemicals, which are often characterized by multi-step batch syntheses and relatively low volume, and where speed to market and rapid ramp-up are essential for commercial success.
This article explains how a direct scaleup strategy can be used to successfully move a new process directly from the bench to the commercial scale without demonstration in a pilot plant. This approach involves conducting process development research in 1-8-L, geometrically similar miniplants, with a focus on simulating expected manufacturing conditions and testing the operating boundaries. It emphasizes understanding particle processing, heat management, agitation, trace chemistry and other scale-sensitive issues.
Choosing a scaleup strategy
Scaleup is defined as "The successful startup and operation of a commercial size unit whose design and operating procedures are in part based upon experimentation and demonstration at a smaller scale of operation" (1). Many factors must be considered when selecting the scaleup strategy. Answering a few process-specific and business-related questions early is key to a successful startup.
Process factors
* What are the critical factors of the new chemistry and process? Are extreme temperatures, pressures or other conditions required? Are operating instructions complicated?
* Does the process involve a single reaction, or is it a multi-step synthesis? If the last step in a multi-step process will be piloted, will it be necessary to also make intermediates at the pilot-plant scale, or are they commercially available?
* Are new chemical technologies, unit operations or equipment being considered?
* How novel is the new process? Have similar reactions or processing steps been successfully scaled up?
* Will the new process be run in batch, semi-batch or continuous mode?
Business factors
* Does the commercial success of the project depend on a flawless initial production...