The TSR A Kinetics Instrument B.W.Wojciechowski President SE Reactors Inc.

What Is a TSR A TSR is a kinetics instrument built around any of the established reactor configurations - PFR, CSTR or BR - but operated in an unconventional way: the temperature of the input stream and of the reactor is ramped in a prescribed way, rather than being maintained at isothermal conditions.

The Advantage of a TSR By ramping the temperature, one quickly obtains data over a range of temperatures rather than at one isothermal condition. TSR operation requires a number of such rampings, at different feed rates, and therefore always yields data over a range of reaction temperatures and conversions.

Interpreting TSR Data The raw data from the TSR is uninterpretable by conventional means. It is made interpretable by the use of algorithms patented by SE Reactors. The algorithms are based on fundamental equations for the mass and heat balances present during temperature scanning, and do not involve any ad hoc assumptions.

How Efficient Is Temperature Scanning? A TSR experiment can be completed in as little as 5 hours. The raw data is then processed to yield an unlimited number of rates within the range of temperatures and conversions observed. The masses of data generated allow us to see rate expressions as 3D surfaces in (X, T, t) or (X, T, r) or another space.

Kinetic Runs Seen As Surveying TSR results make it clear that kinetic studies involve a survey of such a “kinetic surface”. Its shape is surveyed by measuring the (X, T, t) co-ordinates at several points. An algebraic expression is fitted to the “rate surface” derived from these points. Because of the laborious nature of the experimental work involved in this surveying method, conventional kinetic studies collect a sparse and error-prone set of survey points.

Kinetic Surface Defined by a TSR

Kinetic Survey by TSR TSR surveying methods are quite different. TSR methods can be compared to surveying of a surface by satellite. Continuous traverses of the surface are taken along several correlated paths. Both the paths and the traverses are governed by internal consistencies. This allows us to apply powerful mathematical procedures designed to eliminate “noise”.

A Systematic Survey by TSR

What is the Final Result? The TSR supplies enough well-conditioned data so that complex mechanistic rate expressions can be fitted to the data with confidence. A TSR can perform as many as three experiments per day, each yielding a complete surface in the range of variables investigated, offering a thorough understanding of the kinetics involved.

Mechanism of MeOH Reforming The Steam Reforming of Methanol presents a complicated reaction system studied using the TSR. Two types of sites, many surface intermediates, and highly coupled reaction rates are connected by equilibria and common intermediates. This results in three coupled, complex rate expressions, making parameter estimation difficult. The overall reaction chemistry can be envisaged as a combination of three equilibria:

Equilibria in MeOH Reforming Steam Reforming: Decomposition: Water Shift:

The Kinetics of the Reaction The Steam Reforming Rate: Decomposition Rate: The Water Shift Rate:

Confirming the Validity of the Parameters CH3OH

vs Isothermal Operation Temperature Scanning vs Isothermal Operation The TSR yields all the necessary kinetic data in a matter of hours, not months; TSR data is reliably purged of random experimental error by the use of advanced mathematical methods; The quantity and quality of data available from the TSR makes the fitting of complex or mechanistic rate expressions believable; The TSR allows a deeper understanding of the reaction kinetics, with or without the fitting of a mechanistic rate expression. The hardware, analysis and system calibration procedures are similar to those commonly used;

The Temperature-Scanning Plug-Flow Reactor A Kinetics Instrument