Applied Petrochemical Research (v.8, #3)
New trends in improving gasoline quality and octane through naphtha isomerization: a short review by Salman Raza Naqvi; Ayesha Bibi; Muhammad Naqvi; Tayyaba Noor; Abdul-Sattar Nizami; Mohammad Rehan; Muhammad Ayoub (131-139).
The octane enhancement of light straight run naphtha is one of the significant solid acid catalyzed processes in the modern oil refineries due to limitations of benzene, aromatics, and olefin content in gasoline. This paper aims to examine the role of various catalysts that are being utilized for the isomerization of light naphtha with an ambition to give an insight into the reaction mechanism at the active catalyst sites, and the effect of various contaminants on catalyst activity. In addition, different technologies used for isomerization process are evaluated and compared by different process parameters.
Keywords: Catalyst; Isomerization; Light naphtha; Octane number; Oil refineries
Two-step sol–gel synthesis of mesoporous aluminosilicates: highly efficient catalysts for the preparation of 3,5-dialkylpyridines by Marat R. Agliullin; Valentin P. Talzi; Nadezhda A. Filippova; Vera R. Bikbaeva; Sergey V. Bubennov; Tatyana R. Prosochkina; Nellya G. Grigorieva; Nama Narender; Boris I. Kutepov (141-151).
The microstructure, acid properties and characteristics of the porous structure of sol–gel-synthesized mesoporous aluminosilicates with Si/Al ratios of 40, 80, and 120 have been investigated. It was illustrated that the main reason for the formation of a narrow mesopore size distribution in the investigated aluminosilicates is related to the close size of the secondary particles of the prepared xerogels. The research revealed that an increase in the Si/A1 ratio leads to a slight decrease in the specific surface and mesopore volume. An increase in the Si/Al ratio from 40 to 120 has proved to reduce the total acidity in ammonia from 554 to 324 μmol/g. It is shown that mesoporous aluminosilicates prepared by two-step sol–gel synthesis show high activity and selectivity in the synthesis of 3,5-dialkylpyridines.
Keywords: Heterogeneous catalysis; Mesoporous aluminosilicates; Multicomponent reactions; 3,5-dialkylpyridines
Hydrogenation of levulinic acid with and without external hydrogen over Ni/SBA-15 catalyst by Mohan Varkolu; Hari Babu Bathula; Young-Woong Suh; David Raju Burri; Seetha Rama Rao Kamaraju (153-162).
A series of Ni/SBA-15 catalysts were prepared by impregnation method for the hydrogenation of levulinic acid (LA) to γ-valerolactone in a fixed bed reactor at atmospheric pressure. The catalysts were characterized by XRD, TPR, AAS, Pulse chemisorption, SEM-EDAX, TEM, BET Surface area and XPS. The catalyst 30 wt% Ni/SBA-15 exhibited excellent catalytic performance (97% yield) at 250 °C due to the presence of superior number of active surface Ni species. While 30 wt% Ni/SiO2 catalyst showed lower catalytic activity (87% yield) at about similar conversion. The co-feeding of formic acid (FA) and water (impurities) with levulinic acid was also evaluated over 30 wt% Ni/SBA-15 which yielded excellent levulinic acid conversion. The noteworthy results were obtained at a molar ratio of FA/LA = 5. The constant catalytic activity during 10 h experiment with an external H2 flow has showed the sturdiness of the Ni/SBA-15 catalyst. On the other hand, a slight decrease in conversion as well as yield during the time-on-stream in the absence of external H2 flow was attributed to the accumulation of carbon species on the catalyst surface.
Keywords: Hydrogenation; Levulinic acid; γ-Valerolactone; With external H2 ; Without external H2 ; 30 wt% Ni/SBA-15
Study of dual-phase drive synchronization method and temperature measurement algorithm for measuring external surface temperatures of ethylene cracking furnace tubes by Zhiping Peng; Jieguang He; Yun Tan; Delong Cui; Qirui Li; Jingbo Qiu (163-172).
Currently, the manual method using hand-held infrared temperature measurement instruments for measuring temperatures on the external surfaces of ethylene cracking furnace tubes is highly subjective and is affected by a number of prominent issues, such as the high temperature working environments, which leads to low efficiency and poor measurement accuracy. Hence, an automatic temperature measurement system based on infrared light is designed and realized. In the system, a dual-phase drive synchronization method is proposed to rotate the thermodetector during horizontal movements, thus realizing automatic batch temperature measurements of the furnace tubes. Moreover, a temperature processing algorithm is developed to automatically identify furnace wall and tube surface temperatures, filter out abnormal temperatures and select only high-quality temperature measurements prior to calculating the final result. Real temperature measurement experiments demonstrated that the dual-phase drive temperature measurement system and temperature processing method are effective and efficient. Compared with the traditional manual way, temperatures obtained using the proposed system are more stable and accurate.
Keywords: Cracking furnace tube; Surface temperature measurement; Dual-phase drive synchronization; Temperature processing algorithm
CO2 Adsorption by Several Types of Pillared Montmorillonite Clays by Ke Wang; Xinlong Yan; Sridhar Komarneni (173-177).
CO2 has been found to be the main anthropogenic contributor to the greenhouse gas effect, thus, the development of carbon capture and storage (CCS) technology is extremely urgent. In this work, two kinds of Al2O3 pillared montmorillonite, one ZrO2-pillared montmorillonite and one TiO2 + SiO2 pillared montmorillonite were prepared and characterized by X-ray diffraction (XRD) for phase formation and N2 adsorption–desorption isotherms for surface area and pore-size distribution. Equilibrium adsorption of CO2 gas was measured at 273 K. CO2 adsorption capacities of pillared clays increased with the increase of their pore volume. The uptakes of CO2 by pillared clays were in the range of 0.53–1.18 mmol/g.
Keywords: Montmorillonite; Pillared clays; CO2 adsorption