A princh of this and a good measure of that...

• Pinch analysis reveals where energy inefficiencies were costing the company
• One measure introduced cut steam use by 30 kW
• Up to 20 % energy savings were reached thanks to all measures implemented  

Pharmaceuticals are typically produced in recorded batches. In general, large amounts of heat and cooling energy are needed, particularly for extraction processes. Good manufacturing practice (GMP) is a critical factor, and it places severe restrictions on changes to material processing.

As a result, one pharmaceutical company used pinch-analysis models focused on detecting and remedying sources of thermodynamic loss (excess energy consumption) in chemical processes.

To compare the effect of different energy-saving measures, a model of the steam system (heat and mass balance, thermodynamic properties) was essential. The model was used to evaluate the following configurations:

• Use of an oil-heated reservoir
• Modification of the gas turbine and the waste-heat boiler
• Installation of a new steam turbine to reduce imported electricity
• Assessment of future steam consumers

Key benefits

Based on the results of the pinch analysis, the company decided to increase heat recovery from the boiler flue gas, and to use it for warm-water treatment. Furthermore, it planned to install an additional buffer tank to the refrigeration cycle.

Another suggested modification was to insert a vertical baffle plate into the buffer tank so the warm water could then be reused. A third project proposal, based on the analysis of composite curves, was to use the existing cooling water exchanger to transfer heat between recycled liquid and waste steam. This would keep the cooling water capacity at the existing level, but the steam demand would decrease by 30 kW, generating valuable energy savings.

Measures implemented during the efficiency drive led to around 20 % less energy use and reported cost savings of some € 310 000, with a payback on investment of 1-2 years.