Single Fluid Heat Transfer Single Fluid Heat Transfer Systems Are Gaining Importance
In API manufacturing, contrary to the traditional use of multiple utilities, single fluid heat transfer systems are advantageous. These systems can be designed even for specific applications, and engineered and built at site.
Active Pharmaceutical Ingredient (API) manufacturing involves batch reaction, work-up, layer separation, filtration, distillation and drying as unit processes. Again, batch reaction involves heating and cooling stages ranging from -40 to +150oC. Conventionally, this was being done with multiple utilities such as chilled brine, chilled water, cooling water, hot water, low pressure steam, high pressure steam etc.
However, this approach has the following major disadvantages:
- More utility header lines required near operating area
- Cross contamination of utility fluids
- Utility changeover by operator
- During change over, utilities are wasted if drained due to mix-up
- Condensate recovery is not feasible
- It may cause thermal shocks due to sudden change in temperature, if gradual change over is not practised
- Accurate temperature control is not possible
- Increases overall cost
Many API processes have temperature as a critical control point, and hence accurate temperature control is essential. This is a significant parameter to be considered while designing multi-product facility or a kilo lab, which is used for carrying out validation batches for the main plant.
While heating to temperature above 150°C and cooling after the reaction is critical – the use of cooling water will lead to formation of steam in the jacket – and thus over pressurisation besides the thermal shock. Due to these factors, single fluid heat transfer systems have gained importance in pharmaceutical and chemical Industries.