IMS Solvent Recovery with Azeotropic Distillation

Bristol, UK

An international multinational pharmaceutical and biotechnology company came to Koch Modular for the design and manufacture of a system that recovers IMS alcohols (ethanol and methanol) from a mixed stream containing IMS alcohols, toluene, fumaric acid, API, IEE, CEE and water. The manufacturing process for pharmaceuticals relies heavily on the use of these organic solvents, though their disposal is costly and environmentally detrimental. Thus, the recovery of these solvents provides an opportunity to reduce these costs and meet increasing environmental and commercial pressures being put on the pharmaceutical industry.

Koch Modular engineers are experts in designing mass transfer and distillation processes, understanding exactly what the client is looking for and needs.

Challenge

Solvent recovery projects are not a unique challenge to Koch Modular engineers. The client wanted a system that recovers IMS alcohols (ethanol and methanol) from a mixed stream containing IMS alcohols, toluene, fumaric acid, API, IEE, CEE (proprietary compounds) and water. Toluene, in particular, is higher boiling point and forms an azeotrope, making for a difficult separation. Trace high-boiling impurities also posed separate challenges due to plugging of the distillation column. Special attention was needed to ensure that these process challenges are overcome and that industrial solvent regulations are met.

SOLUTION

In this system, the distillation process was designed to separate a minimum boiling azeotrope aromatic and heavy impurities from an alcohol solvent. Koch Modular Process Systems performed a proof of concept pilot test in advance of the modular system design. During this test, a representative purified alcohol solvent was generated, allowing the client to test and verify the solvent performance in their manufacturing process. The modular system was constructed in accordance with European CE/PED and ATEX directives.

To fix the problem of trace impurities plugging the column, the sump column temperature was decreased to prevent the impurities to build up to the point that liquid in sump no longer flowed freely. Additionally, the steam condensate was collected in a tank and vented back to a reboiler to avoid a steam plume that often viewed as pollutants even though it is only water vapor.

RESULTS

Koch Modular provided a IMS Solvent Recovery Unit designed to recover IMS alcohols (ethanol and methanol) from a mixed stream containing IMS alcohols, toluene, fumaric acid, API, IEE, CEE (proprietary compounds) and water. The system includes two distillation columns, including their condensers, reboilers, reflux tanks, and pumps.

Koch Modular also provided a control system using a Siemens PLC and Wonderware HMI software. All pressure equipment was designed to meet CE/PED standards. The electrical system was designed to ATEX requirements. The module was export packaged, and shipped by ocean freight to the client for installation.

With waste solvent disposal costs constituting one of the primary concerns in the industry, this pharmaceutical solvent recovery system provides tremendous cost-saving and environmental benefits.