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The reaction kinetics for the liquid phase synthesis of a racemic mixture of the secondary butyl alcohols (SBA) from linear butene isomers (1-butene (1B); cis -2-butene ( c 2B); trans -2-butene ( t 2B)) and water (W) using a macroporous sulfonic acid ion exchange resin as catalyst were determined experimentally in a multiphase CSTR in the temperature range 39–433 K at 6–8 MPa. This range of pressures is necessary to dissolve butenes in the aqueous phase and to ensure a liquid state of all components. For temperatures higher than 423 K the reaction kinetics for the used catalyst size are influenced by mass transfer resistances within the catalyst matrix. The reaction takes place in the water swollen gel phase of the catalysts microspheres. Due to the large excess of water in the gel phase the compositions in the gel phase, in the macropore fluid, and in the catalyst surrounding aqueous phase are assumed to be identical. According to the literature the reaction is rather catalyzed by hydrated acid protons ( specific catalysis ) than by polymer-bonded-SO 3 H groups ( general catalysis ). The experimental results can therefore be described sufficiently by a pseudo-homogeneous 3-parameter rate expression in aqueous phase activities. The forward reaction is first-order in butene. The reverse reaction is first-order in secondary butyl alcohol. The activation energy was determined to be 108 kJ/mol. Practically no pressure dependence could be observed for pressures exceeding 6 MPa. The ever-present isomerization of the linear butenes on acid catalysts was found to be remarkably faster than the hydration of butenes to SBA. Therefore, the isomerization is considered to be always in equilibrium during the olefin hydration. The formation of the possible by-product di- sec -butyl ether (DSBE) was never observed to a measurable extent. Simultaneous chemical and phase equilibria were investigated theoretically using the volume translated Peng–Robinson equation of state (VTPR-EoS) in combination with a g E -mixing rule. Parameters of the used g E -model were adjusted to experimental ternary liquid–liquid equilibrium (LLE) data.

The intrinsic kinetics for the liquid-phase cyclisation etherification of 1,4-butanediol (BD) to tetrahydrofuran (THF) and water were determined in a stirred batch reactor in the temperature range from 373 to 393 K . A sulphonic acid ion exchange resin powder with a particle size of 3–7 μm was manufactured and used as catalyst. The reaction can be regarded as irreversible and proceeds without diffusion limitations inside the catalytic microspheres. The formation of an intermediate containing 1,4-butanediol (BD) on an active site was determined to be the rate-determining step. The reaction product water acts as a strong inhibitor for the intermediate formation. The experimental results can be described by a three-parameter model based on Michaelis–Menten kinetics extended by an inhibition term for water. Within the developed rate equation, concentrations are expressed in liquid-phase activities from the UNIQUAC method in order to consider the nonidealities. The developed rate equation is valid in the whole range of possible concentrations and independent of the solvents used. During the experiments no formation of by-products was observed.

Reactions of solids with liquid reactants can be accelerated in ultrasound fields. Transient bubbles create liquid microjets and increase the amount of dislocations on metallic surfaces. Dynamic experiments and models for the activation of magnesium turnings in the Grignard reaction of chlorobutane and phenylchloride show a relation between the degree of activation and the local energy distribution in the ultrasound field. The local action of transient bubbles and microjets in cavitating sound fields was measured and calculated. This allows the prediction of reaction rates, optimum process parameters and the behavior of different metals in noncatalytic as well as catalytic solid–fluid reactions. A further optimization of reaction rates and safer production of organometallic compounds was reached by applying mixtures of calcium donated magnesium. These alloys are very brittle and can be cleaved under ultrasound. High reaction rates with a variety of organic chlorides and phenyl fluoride are observed with sonicated magnesium calcium alloys.

We constructed a novel sonochemical reactor for heterogeneous solid fluid reactions which uses high intensity ultrasound from a concentrator horn. It can be shown that the concept of a conical funnel fits the demands for a nearly perfect radiation effectiveness and a good reaction management. Theoretical investigations concerning the sound field in both the sonotrode and the reactor for different cases give some insight in the fundamental relationship between consumed electrical power, converted mechanical energy in the transducer and radiated sound energy. The main energy conversion paths in the liquid are presented as well. A Grignard reaction was investigated in the reactor and showed extreme reaction rate enhancements which are due to a mechano chemical reaction kinetic caused by imploding bubbles and the thereby generated shock waves and microjets. A simulation of the particle size distribution during simultaneous reaction the fragmentation in an ultrasonic loop reactor was developed to correlate measured size distributions with model equations.