REVIEW: TEKNOLOGI PEMBUATAN SORBITOL DARI TEPUNG TAPIOKA

Sugar alcohol or sorbitol is a derivative product of carbohydrates, namely glucose through the hydrogenation process with hydrogen gas. The glucose used comes from flour, because the carbohydrate content in tapioca flour is considered the highest compared to other flour ingredients. Before the hydrogenation process is carried out, tapioca flour is enzymatically hydrolyzed so that the starch is broken down into glucose. The process of making sorbitol can be done in two ways, namely the electrolysis reduction process and the hydrogenation process with the help of a nickel catalyst. This literature study aims to determine the technology for making sorbitol and its advantages and disadvantages, both in terms of product and process, so that it can be used as a reference in selecting processes in sorbitol manufacturing plants. The catalytic hydrogenation process has advantages, namely the resulting yield is greater and the operating costs are relatively cheaper. The catalytic hydrogenation process also has several disadvantages, namely that it requires good safety handling because it requires high pressure in the process.

THE USE OF ULTRASOUND IN THE PREPARATION OF THE CATALYST Ru/HPS MN 100 AND ITS ACTIVITY IN THE PROCESS OF HYDROGENATION OF XYLOSE AND LACTOSE

В работе рассмотрена возможность использование ультразвука при получении рутений содержащей каталитической системы Ru/СПС MN 100. Проведено кинетическое тестирование данного катализатора и сравнение его активности с таким же катализатором, но синтезированным без использования ультразвука, в процессе гидрирования ксилозы и лактозы до соответствующих полиолов - ксилита и лактита. Процесс гидрирования осуществлялся в реакторе периодического и непрерывного действия при оптимальных условиях (температуре, концентрации моно- и дисахарида, парциальном давлении водорода, скорости подачи водного раствора ксилозы и лактозы и скорости подачи водорода). Установлено, что ультразвуковая обработка рутениевого катализатора способствует повышению его активности, что отражается на увеличении конверсии моно- и дисахарида при проведении процесса в периодических условиях, при этом практически не происходит изменения конверсии субстратов при их гидрировании в реакторе проточного типа. The paper considers the possibility of using ultrasound in the production of ruthenium-containing catalytic system Ru/SPS MN 100. Kinetic testing of this catalyst was carried out and its activity was compared with the same catalyst, but synthesized without the use of ultrasound, in the process of hydrogenation of xylose and lactose to the corresponding polyols - xylitol and lactite. The hydrogenation process was carried out in a periodic and continuous reactor under optimal conditions (temperature, concentration of mono - and disaccharide, partial pressure of hydrogen, the rate of supply of an aqueous solution of xylitol and lactite and the rate of supply of hydrogen). It was found that ultrasonic treatment of the ruthenium catalyst contributes to an increase in its activity, which is reflected in an increase in the conversion of mono - and disaccharide during the process under periodic conditions, while there is practically no change in the conversion of substrates during their hydrogenation in a flow-type reactor.

Synthesis of Ni/NiAlOx Catalysts for Hydrogenation Saturation of Phenanthrene

The saturation of octahydrophenanthrene was the rate-determining step in the hydrogenation process from phenanthrene to perhydrophenanthrene, which was due to the steric hindrance and competitive adsorption of octahydrophenanthrene. In this work, a series of Ni/NiAlOx catalysts with a uniform electron-deficient state of Ni derived from the nickel aluminate structure was synthesized to overcome the disadvantage of noble catalyst and the traditional sulfided catalysts in the saturation hydrogenation process of phenanthrene. Results showed that the catalyst calcinated at 650°C possessed more Ni2+ (∼98%) occupying octahedral sites and exhibited the highest robs (1.53 × 10−3 mol kg−1 s−1) and TOF (14.64 × 10−3 s−1) for phenanthrene hydrogenation. Furthermore, its ability to overcome steric hindrance and promote the rate-determining step was proven by octahydrophenanthrene hydrogenation. Comparing the evolution of hydrogenation activity with the change in the electronic structure of surface Ni sites, it was shown that the increase of metallic electron deficiency hindered the π-back bonding between surface Ni and aromatic rings, which was unfavorable for aromatic adsorption. As a result, the phenanthrene hydrogenation saturation performance can be enhanced by stabilizing the electron-deficient state of surface Ni on an optimal degree.