Process Design of Stevia Based Sweetener Manufacturing Plant

Project Synopsis

Project Summary

PROCESS DESIGN FOR STEVIA BASED SWEETENER PRODUCTION PLANT

Process Engineering Associates, LLC (PROCESS) was contracted by the client to provide a Front-End Loading Phase 3 (FEL-3) process design package for a proposed commercial scale production facility to produce a natural sweetener from the stevia plant. The stevia plant is a small, sweet-leaf herb of South American origin. The sweetener naturally occurs in the stevia plant and has received Generally Recognized as Safe (GRAS) status per the U.S. Food and Drug Administration (FDA).  The commercial facility will produce the stevia based natural sweetener with a purity comparable to currently available stevia based sweeteners and with the last steps in the process designed utilizing Current Good Manufacturing Practice (cGMP) guidelines.  The commercial processing facility design was scaled up and optimized from lab/pilot scale data supplied by the client and various process equipment vendors.

PROCESS performed the following project tasks:

• Several extraction technology alternatives were evaluated to optimize extraction efficiency. These were submitted for the client’s consideration.  The pilot process used a tank based batch extractor. The final process design included a semi-continuous extraction technology.

• Heat & material balance (HMB) calculations and a process flow diagram (PFD) were prepared for the final process.  This involved detailed review of existing lab/pilot data as well as actual process data from key technology steps provided from various equipment vendor tests.  PROCESS generated a design case based on the appropriate data.  PROCESS then used its licensed commercial computer process simulation software (Chemstations’ CHEMCAD) to perform sensitivity analyses and generate HMB calculations for the process design.

• Unit operations that were modeled and designed included: Semi-Continuous Extraction, MVR-based Vacuum Evaporation, Purification by Nano and Micro Filtration, Deodorization/Decolorization, Stripping, Spray Drying, Agglomeration, Blending, and Packaging.  Additional design considerations were incorporated into the cGMP governed part of the process including sterilization and Clean in Place (CIP) systems.

• A preliminary overhead view and side view equipment layout drawings were generated.  The ascertained preliminary equipment sizing and space envelope dimensions were represented to scale in the equipment layout drawings.  The build strategy was to modularize the process in design capacity increments that matched the build-up of the planting cycles.

• A preliminary total installed capital cost estimate was prepared using equipment sizing data and applying the appropriate Lang factor.

• A full set of piping and instrumentation diagrams (P&IDs) for the process was produced.  From the P&IDs, instrument and valve lists were generated for all instruments and automated valves associated with the PLC control system.  These lists also provided pertinent information for data sheet specifications.

• Process data sheets were produced for all major equipment including vessels, heat exchangers, chillers, filters, pumps, and relief valves.  Heat demands from the HMB were used to calculate utility requirements for cooling water to heat exchangers and chillers.  The energy balance portion of the HMB was used to calculate utility usage quantities for heating requirements.  System pressures and flow rates from the HMB were used to generate pump and relief valve requirements.

A complete FEL-3 package that included the above-mentioned documentation was issued to the client. The FEL-3 package provides information that is being carried forward to a more detailed mechanical design phase, which the client intends to contract to an EPC firm.

Industry Type

• Food Products

Utilized Skills

• Process scale up
• Process optimization
• Process design package (PDP) development