A synthetic liquid-phase heat transfer fluid is helping pharmaceutical systems meet lower-than-ever temperature demands.

Cambridge uses the low-temperature heat transfer fluid to control the temperature of its cryogenic vessel, which reaches temperatures as low as -150°F (-100°C).

Trends in the pharmaceutical industry continue to demand systems that can operate at lower-than-ever temperatures. Cambridge Major Laboratories, a Germantown, Wis.-based chemistry outsourcing partner to some of the world’s leading pharmaceutical and biotechnology companies, was one such company seeking a low-temperature solution. The company, which specializes in chemical process development and advanced multi-step organic synthesis, operates two facilities near Milwaukee, Wis., that comprise process chemistry laboratories, kilo labs, pilot plants and analytical laboratories. Its products include pharmaceutical intermediates, active pharmaceutical ingredients (APIs) and other fine organic chemicals.

When the company expanded into cryogenic synthesis a couple of years ago, it needed a high-performance heat transfer fluid for the process.

“We were looking for a low-temperature fluid with the capability of going below -150°F [-100°C],” says Robert Petersen, pilot plant manager at Cambridge Major.

Precise temperature control is essential for ensuring the high degree of product quality necessary in the pharmaceutical industry. For more than ten years, Cambridge Major has used a synthetic liquid-phase fluid, Therminol D-12 supplied by Solutia, to transfer heat and control temperatures in its pilot plant operations. Approximately 3,000 gal of the fluid circulate continuously through three loops - one of which operates at 320°F (160°C), another at ambient, and one at -13°F (-25°C) - in each facility to heat or cool the 20 vessels used for various projects. A sophisticated balancing system ensures that the appropriate fluids are automatically transferred from tank to tank as needed to keep all of the loops at a constant volume.

Cambridge had selected the synthetic liquid-phase fluid those years ago because of its ability to handle wide temperature ranges as well as for its inertness. “We’re using glass-lined vessels,” explains Petersen. “Other fluids such as glycol would turn acidic in our process and cause proton-penetration through the metal, which can adversely affect the integrity of the glass.”

The D-12 provided a safe, effective solution, and the company continued to specify the fluid as it expanded its operations. When Cambridge Major decided to scale up process capabilities by installing a cryogenic vessel, a different fluid capable of handling the vessel’s extremely low temperatures, was necessary.

“D-12 is designed for temperatures as low as -50°F [-45°C], and it starts to crystallize below -126°F [-88°C]. With temperatures in the cryogenic vessel reaching to -150°F, we knew we would need a different fluid for this application” says Petersen.

Petersen discussed the new cryogenic application with engineers at Solutia, and they recommended Therminol VLT. Designed for single-fluid heating and cooling systems operating between -175 and 350°F (-115°C and 175°C), the fluid can be used in many general-purpose processes where both cooling and heating are required. It also allows low-temperature operation with normal centrifugal pumps. And, because it has low-temperature capabilities, it can help increase product yield and reduce production time.

The VLT fluid provided the process flexibility required for the cryogenic synthesis process. “We could have gone with a different type of system for this vessel, such as alcohol. But alcohol has a higher flammability rating and a much higher pressure differential when it heats up. The VLT seemed to be a better choice for our application,” says Petersen.

According to Petersen, the VLT fluid has performed as expected since the company began using it two years ago.

“The cooling transfer of the fluid is efficient, and we haven’t had any problems since we started using it. It’s a high-end, specialized product, but it does the job and we’re happy with it,” he says.

For more information about Cambridge Major Laboratories, visit www.c-mlabs.com.
For more information about Solutia Inc. and its low temperature heat transfer fluids, call (800) 433-6997; visit www.therminol.com; or e-mail team.therminol@solutia.com.