The influence of reaction conditions in the transformation of methanol into gasoline (temperature, time on stream, and contact time) on the deposition and nature of coke (composition, H/C ratio) and on its location in the porous structure of a H-ZSM5 zeolite-based catalyst has been studied in an isothermal fixed-bed integral reactor. The distribution of the coke within the porous structure of the catalyst is similar to that proposed for other reactions on H-ZSM5 zeolites, and the highly hydrogenated character of coke and its instability is noteworthy. Coke deposition has been related to catalyst acidic site deterioration and to a kinetic model for catalyst deactivation in an integral reactor.

Deposition and Characteristics of Coke over a H-ZSM5 Zeolite-Based Catalyst in the MTG Process

A study has been made of the activity recovery of H-ZSM5 zeolite based catalysts, which have been used in reaction-regeneration cycles in the transformation of methanol into gasoline. Catalyst stability is sensitive to catalyst calcination conditions (temperature and time) and to zeolite Si/Al ratio. From experiments carried out on automated reaction-regeneration equipment provided with an isothermal fixed-bed reactor, optimum catalyst equilibration conditions have been determined, in order to minimize the irreversible deactivation in the regeneration step. The effect of this step on the catalyst acid structure has been studied.

Catalyst Equilibration for Transformation of Methanol into Hydrocarbons by Reaction−Regeneration Cycles

From experimental results obtained in a wide range of operating conditions (temperature and contact time) in an isothermal fixed-bed integral reactor, the usefulness of the model of Schipper and Krambeck (Chem. Eng. Sci. 1986, 41, 1013−1019) for simulating the operation has been proven in the 300−375 °C range. The validity of a deactivation kinetic model dependent on the composition of the three lumps for the MTG process (oxygenates, light olefins, and the rest of the products) has been proven, for a wide interval of compositions of the lumps. These compositions correspond to different states of catalyst deactivation. The use of this model in the simulation of the integral reactor avoids noticeable errors inherent to the nonconsideration of the effect of composition on the deactivation.

Concentration-Dependent Kinetic Model for Catalyst Deactivation in the MTG Process

https://escholarship.org/content/qt83k4x50r/qt83k4x50r.pdf?t=p0lo1o

A model-free method for calculating vapor-liquid equilibria for multicomponent systems from total-pressure or boiling-point data

A rigorous method for calculating thermodynamically consistent vapor composition data in isothermal binary systems is fully developed. The method does not require the simplifying assumptions of ideal gas and negligible liquid volume and the result is a first-order differential equation for

David B. Manley

Papers

Direct Solution of the Isothermal Gibbs-Duhem Equation for Multicomponent Systems

Direct solution of the isothermal gibbs‐duhem equation by an iterative method for binary systems