(389a) A Suitable Disengagement: Adventures In a Multi-Phase Reaction System

A
Suitable Disengagement:  Adventures in a Multi-phase Reaction System

Cheryl
Teich

The Dow Chemical Company, Spring House, PA
Core R&D/Process Chemistry and Development

In the early business development of a niche specialty
product, a small-scale CSTR provided adequate volumes.  The product is generated as a gas that forms through
a complex reaction pathway and must disengage from a mixture containing two
distinct solids and multi-component liquid and gas phases.  Extended product
holdup can lead to yield loss via byproduct and mer formation, and even to a
potentially hazardous condition.  Safe and successful operation of the process
relies on balancing the reaction pathway with adequate reactor mixing and gas
disengagement.  This had been achieved with the existing process through
extensive operating experience.

The potential for step growth in the business led to an
examination of reactor options to supply the larger volumes.  A concern was
that a larger CSTR might not provide adequate gas disengagement and that the
process would suffer as a result.  The first step in generating the next
generation reactor design was to capture process understanding in the process
scheme shown below.

Development of the process scheme led to an examination of the
scale-independent chemistry and its interaction with equipment-specific
agitation configurations.  The development program used various laboratory
reactors and modeling tools such as DynoChem® and Aspen Plus® to deliver volume-specific
recommendations on reactor type and designs to meet the growing business needs.