Processos para realizar uma reação bifásica gás/líquido continua a alta pressão, para produzir mentol opticamente ativo, e, para adaptar o volume de reação

a invenção refere-se a um método para realizar uma reação contínua bifásica gás/líquido a alta pressão, em que um gás e um líquido são introduzidos em uma zona retromisturada de um reator, e o gás é disperso no líquido na zona retromisturada. uma mistura de reação flui através da zona retromisturada e uma zona com restrição de retromistura uma após a outra, e um produto de reação líquido é retirado em uma saída de produto de reação da zona de restrição de retromistura. A process for performing a continuous gas/liquid biphasic high-pressure reaction, wherein a gas and a liquid are introduced into a backmixed zone of a reactor and in the backmixed zone the gas is dispersed in the liquid by stirring, injection of gas and/or a liquid jet, a reaction mixture consecutively traverses the backmixed zone and a zone of limited backmixing, and a liquid reaction product is withdrawn at a reaction product outlet of the zone of limited backmixing, wherein the reactor comprises: an interior formed by a cylindrical vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by means of internals into the backmixed zone, the zone of limited backmixing and a cavity, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a third internal element which in the interior extends in the longitudinal direction of the reactor and is open at the bottom, wherein the third internal element forms the cavity in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume. The reaction volume of the reactor used in the process can be reversibly reduced in simple fashion. The invention further relates to a process for adapting the reaction volume of a reactor suitable for performing a gas/liquid biphasic high-pressure reaction having an outlet for a liquid reaction product in which an internal element is arranged so as to form a cavity open at the bottom in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume.