An original simplified mathematical model of the process of tert-butyl alcohol dehydration in a catalytic zone of the reactive distillation unit with the downward concurrent flow of liquid and vapor phases is developed. The system of heat and mass balance equations includes relationships that allow determining changes in temperature as well as gas and liquid compositions caused by a chemical reaction along the catalyst bed height. Results of calculation of the temperature profile along the catalyst bed height, carried out using the developed model, are in good agreement with data from our previous laboratory studies as well as with data obtained during trial operation of an industrial reactor. (C) 2019 Elsevier Ltd. All rights reserved.
The paper deals with experimental studies of cyclopentane synthesis from dicyclopentadiene via reactive distillation. In the reactive distillation column, there are separate zones for the reaction with downward concurrent flow in the catalyst bed and for purification of the reaction products via distillation. The influence of the process pressure and molar ratio H 2 : C 10 H 12 on the conversion was studied. The temperature elevation in the catalyst bed was shown to increase the proportion of dicyclopentadiene in the reaction products. The obtained experimental results demonstrated the high conversion and selectivity of the continuous synthesis of cyclopentane from dicyclopentadiene in reactive distillation units.
The experimental results on tert -butanol dehydration are discussed. The influence of the catalyst bed temperature, water content in the feed flow, and the temperature of the feed flow on the tert -butanol conversion was experimentally studied in the presence of the KU-2FPP and Purolite СТ275 catalysts. The isobutylene yield was established to depend mainly on the heat supply to the reaction zone. The countercurrent flows of the phases through the catalyst bed were shown not to allow the process to be intensified using a more active catalyst. It was experimentally demonstrated that the arrangement of downward concurrent flows in the catalyst bed led to an increase in the efficiency of tert -butanol decomposition over a more active Purolite CT275 catalyst.
A conjugate solution has been obtained for ascending cocurrent turbulent gas flow and laminar liquid wavy film flow in an inclined flat channel without drop entrainment. The waves have been represented as surface roughness features. Experimental studies have been conducted for air-water, air-diethylene glycol, and air-aqueous sucrose systems, and the results have been compared with the calculated data.
Получено сопряженное решение для газового турбулентного потока и жидкой ламинарной волновой пленки при восходящем прямотоке без брызгоуноса в плоском наклонном канале. Использована модель представления волн как шероховатостей. Проведены экспериментальные исследования и сопоставление с ними результатов расчетов для систем воздухвода, воздухдиэтиленгликоль, воздухводный раствор сахарозы.
The paper presents experimental study of possibility of heavy pyrolysis tar refining to get a naphthalene fraction. Authors offer approach of atmospheric distil-lation with direct superheated steam. According experimental data optimal techno-logical parameters of the process are determined: the temperature of feedstock heat-ing is strictly not above 150°С, the temperature of superheated steam is 300÷325°С, mass ratio of feedstock:steam is 1,08:1. It is important to note that value of mass ra-tio feedstock:steam is strongly dependent on potential content of naphthalene in feedstock and defines distillate fraction.
A model of interaction of a gas stream with a film of fluid moving in the laminar wave regime based on representation of waves as roughness is proposed. It allows calculating hydraulic resistance of a pipe, average thickness of a film, shear stress on the boundary separating phases, velocity field and a number of other characteristics. Adequacy of the model is demonstrated by comparison with open literature experimental data in a vertical pipe.
