Automatic continuous online monitoring of polymerization reactions

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Automatic continuous online monitoring of polymerization reactions (ACOMP) is a technique developed at Tulane University by W.F. Reed in 1998,^[1], with the first peer-reviewed paper appearing in 1998.^[2]

Introduction

Polymerization reactions are difficult to monitor in real-time, as characteristics and properties of the polymers are often not exactly known, until after the reaction is already complete. This technique, ACOMP. monitors these reactions in real-time by automatically and continuously diluting small streams of polymer out of the reactor and then running the sample though widely accepted detectors to measure such standard parameters as Refractive index, Light scattering, and Intrinsic viscosity, thus characterizing the polymer as the reaction is continuing. " ACOMP can be used as an analytical method during Research and devleopment, as a tool for reaction optimization at the bench and pilot plant level and, even for feedback control of full-scale reactors.^[3][4]

The method can determine in a model-independent fashion the evolution of average molar mass and intrinsic viscosity, monomer conversion kinetics and, in the case of copolymers, the average composition drift and distribution.^[5];it is a direct measurement, not based on the theoretic understanding of the reaction. ACOMP is applicable in the areas of free radical and controlled radical homo- and copolymerization, polyelectrolyte synthesis, heterogeneous phase reactions, including emulsion polymerization, adaptation to batch and continuous reactors, and modifications of polymers.^{[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]}

ACOMP as a tool for efficiency

ACOMP is envisioned as an energy saving and efficiency optimizing technology for the polymer manufacturing industry. Different reaction parameters such as temperature, pressure, and reagent feeds can be adjusted according to what ACOMP analyzes in real-time, maximizing the efficiency of the reaction and reducing the problem of inconsistent product quality and wasted batches.

Applications

The proprietary platform developed by Wayne Reed and coworkers, termed Automatic Continuous Online Monitoring of Polymerization reactions, or ACOMP, has been demonstrated in the laboratory environment since 1998, with over 30 publications in high-impact, peer-reviewed journals.^{[citation needed]} , It has been applied to polycondensation, free radical, controlled radical, other 'living' type reactions, and post-polymerization reactions, such as grafting, etc., and has been applied in solvent, bulk and inhomogeneous phases, such as emulsion and inverse emulsion, and in batch, semi-continuous and continuous reactors.

The ACOMP front-end samples the reactor continuously, producing a dilute sample stream on which yjr multiple analytical measurements are simultaneously and continuously made. These include light scattering, viscosity, refractivity, conductivity, ultra-violet absorption, etc. The types of instruments can be tailored to the specific application. This data yields continuously the derived properties of the amount of reagents converted to polymer, polymer molecular weight, intrinsic viscosity, average composition drift and distribution, and many other properties, and consequently indicates when the reaction is complete, and shows whether there are problems during the reaction, and whether the product is according to specification.

Status

ACOMP is fully proven at the laboratory level, and was commercially available for this use under license from Varian Inc., up until the beginning of 2009. Due to the current financial crisis and massive layoffs, however, Varian Inc. cancelled the license with Tulane for the ACOMP patents, and now PolyRMC is seeking to develop the technology further. Specifically, PolyRMC is looking for potential collaborators for a technology transfer on a non-profit basis through the Center. This would involve preliminary testing to prove the feasibility of adapting the technology to a specific product. It would also involve actual implementation on a larger scale reactor i.e. a pilot reactor or even a full-sized reactor.

The potential for decreasing reaction times by running reactions closer to their thresholds could provide energy savings, and increase output without any further capital investments. Monitoring reactions in real-time can also provide data on the quality of the polymer being produced so that product consistency can be controlled more closely, and finally wasted batches, due to failed polymerizations, can be eliminated. All of these advantages could make ACOMP very cost-advantageous for any end-users of the technology, and help to increase the overall efficiency of the polymer manufacturing sector as a whole. Other potential national or global impact of ACOMP mass-adaptation may include 1) saving petroleum based and other non-renewable resources in polymer production, 2) advances in novel material properties, quality, versatility, yield, and applications which can lead to better energy saving materials, such as light-weight construction and transportation materials, oil recovery polymers, etc., 3) less greenhouse gas emission per pound of product, 4) less chemical contamination of soil, water, air and surrounding communities and 5) enhanced profitability due to efficiency and quality gains, leading to 6) retention and expansion of this manufacturing sector in the US, with its broad spectrum of blue and white collar jobs, and 7) a quantitative basis for evaluating energy efficiency of polymer manufacturing.

References