Novel Tubing Microreactor for Monitoring Chemical Reactions

Abstract

There is an expanding interest in small-scale methods to evaluate catalysts and chemical reactions at a variety of conditions, ranging up to 6.9 MPa (1000 psig) and 300 degrees C. Multiwell parallel batch techniques are most commonly applied in high-throughput screening systems. In contrast, we describe here a rapid, serial, highly controllable method based on LC-type steel tubing rated for high pressures. The tube, containing a variety of flowing ingredients, such as carrier solvents, catalyst formulations, and reactants, is self-heated ohmically using electrical current from a power supply monitored and regulated with a precision of 0.01%. An array of voltage taps arranged along its length serves to sense the real-time temperature profile of the tube. Reactions are seen as temperature pulses progressing through the reactor, in zones of 200 microL each, and tracked with a temperature precision of 0.1 degrees C. A unique pressure controller was devised to maintain constant reactor pressures despite effluent viscosity fluctuations due to polymerization. Several chemical reaction systems have been characterized to date, including decomposition reactions of di-tert-butyl peroxide, polymerizations of styrene, formation of polyethylene from ethylene, and copolymerization of ethylene with 1-octene. For ethylene polymerization, the amount of mass of polymer formed is proportional to the responses observed.

Study of Ethylene Polymerization Under Single Liquid Phase and Vapor‐Liquid Phase Conditions in a Continuous‐Flow Tubular Reactor

“…The construction and operation of the standard non-isothermal reactor has been previously described [1][2][3]. The reactor preheater, catalyst addition tee, and reactor section are shown in Fig.…”

“…This work is a continuation of the effort that had been made at Dow to make use of an electro-thermal microreactor (an ohmically-heated CFTR). The details of the operations and applications of this reactor have been extensively reported in several internal and external publications [1][2][3]. In summary, a tubing electro-thermal micro reactor (ETMR), which was ohmically heated, was developed and used for monitoring polymerization reactions at the milligram scale.…”

“…This is able to display the reaction zone pulses in real time while performing the many control tasks at a lower level. The reactor pressure is set by the active pressure controller [2]. At the onset of this work, it was not obvious that the pressure controller would work with the vapor-liquid phase.…”

Organic Synthesis with Microstructured Reactors

“…In the field of polymerizations, a serial screening approach for monophasic liquid processing of metathesis catalysts for ethylene polymerization was used [60]. The impressive number of one hundred processed volumes per day is above the screening capability of conventional, parallel working apparatus for polymerizations like Parr reactors.…”

Integrated microfluidic reactors

“…Fused glass25,26 and steel27,28 capillary tubes with inherent microscale internal dimensions, provide modular building blocks for assembly of microfluidic reactors on demand. These tube-based microfluidic networks can be applied for reactions with unique properties.…”