(26d) Dynamic Kinetic Test Unit for Determination of Kinetic Parameters Under Prototype Conditions

The Dynamic kinetic test unit (DKTUnit) is an innovative approach for conducting catalytic reaction tests to determine kinetic parameters in a prototype environment of single-phase and two-phase flow reactors that are typical of reactive distillation (RD) and other heterogeneous catalytic reactors.  DKTUnit focuses on a kinetic test unit in which process conditions can be closely simulated, thereby reducing the uncertainty associated with scaling laboratory test data to a pilot plant RD column and other catalytic flow reactors.  Once validated using the pilot plant, this kinetic test unit can even bypass further pilot plant testing by applying the data, with appropriate design tools, to commercial units with high degree of certainty. 

Currently, batch kinetic experiments are typically carried out using a stirred reactor in which catalyst particles are allowed to move freely within the reactive liquid media.  The rate of reaction as a function of time is monitored by taking and analyzing liquid samples using Gas Chromatography (GC) or other analytical methods.  The major problems with this approach are that the fluid dynamics associated with catalyst loading in side reactors and structured packed columns – the porosity and catalyst effectiveness – cannot be simulated.  As a result, there is unknown degree of uncertainty in applying kinetic parameters obtained with batch experiments to performance prediction of flow reactors with heterogeneous catalysts.  Employing test data from a pilot-scale RD system, an adjusting parameter for catalyst effectiveness is commonly used for validating the performance prediction models or simulation codes, such as ASPENPlus.

DKTUnit is based on a patented High Temperature Fouling Unit (HTFU) for petroleum fouling that has been validated in refinery service.  The unit consists of an autoclave with internals designed for simulating prototype flow conditions of catalytic reactors.  DKTUnit consists of four configurations: a) flow tube equipped with impeller to induce flow across catalyst bag mounted in the flow tube; b) a similar configuration with structured catalyst packing mounted in the flow tube; c) catalyst bags mounted on a rotating frame for simulating liquid cross-flow across catalyst bag; and d) catalysts bags mounted on a rotating frame for simulating parallel-flow of catalyst bags.  DKTUnit uses a variable speed impeller and frame mounted on a shaft with variable liquid flow across catalyst so that kinetic data can be determined.         

A preliminary analysis is carried out for developing a methodology for applying the kinetic parameters determined by the DKTUnit to flow reactors as well as RD.  The results from this design study will be presented and plans for applying the DKTUnit to RD processes will be discussed.