liquid hourly space velocity
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Author(s):  
Eli H. Olmos-Cerda ◽  
Georgina C. Laredo ◽  
Patricia Pérez-Romo ◽  
Ricardo Águeda-Rangel ◽  
Alfonso García-López

Abstract The study of the best experimental conditions and catalyst for the hydrogenation (HYD) of light cycle oil (LCO) for upgrading purposes was carried out. The objective was to examine the ability of two commercial hydrotreatment (HDT) catalysts for selective aromatic saturation. The effect of the hydrotreatment operation parameters (temperature, pressure, liquid hourly space velocity, H2/HC ratio) on the sulfur and nitrogen contents and in the saturation of aromatic hydrocarbons was also investigated. The goal was to obtain the highest conversion to mono-aromatic hydrocarbons from this di-aromatic (naphthalene derivatives) type feedstock, and at the same time to get reasonable hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) performance to avoid contaminant hydrocarbons for the next step (usually hydrocracking, HCK). An appropriate hydrotreated product with the highest concentration of mono-aromatic derivatives, a minimum reduction on the total aromatic content, and suitable decrements of sulfur and nitrogen compounds, was achieved using a cobalt-molybdenum supported on alumina catalyst, at 330 °C, 5.5 MPa, and a liquid hourly space velocity of 1.1 h−1. Additionally, the kinetics of the HDA was studied, assuming a lump characterization into tri-, di- and mono-aromatic and aliphatic hydrocarbons, pseudo-first-order reaction rates between these conversions, and thermal losses and diffusional resistances to be undetectable.


Author(s):  
Toshio Shinoki ◽  
Masaaki Kamizono ◽  
Koshi Katagiri ◽  
Masaki Kusumi ◽  
Yasuyoshi Takeda ◽  
...  

Abstract The authors develop a small and simple steam-reforming reactor in a home-use size for such various heavy-hydrocarbons fuels as n-octane, n-decane, n-tetradecane, and n-hexadecane in addition to n-dodecane and measure the inside-temperature profile and the molar fractions of main-gas components such as H2, CH4, CO, and CO2. This reactor is designed only for laboratory-test use, not for a commercial product. As a result, the authors successfully achieve suitable inside-temperature profiles, namely, temperature almost linearly increases in the downstream direction along a reactor, under two conditions such as 600–950 K at the upstream end of the catalyst-layer bed in the reactor and less than 1070 K everywhere in the reactor. And, the authors reveal the effects of the liquid-hourly space velocity (LHSV) upon the molar fractions, a conversion ratio and reforming efficiencies for various heavy-hydrocarbons fuels. All the molar fractions, which agree well with thermochemical-equilibrium theory, are approximately independent of LHSV. The conversion ratio is about 90% for LHSV ≤ 0.6 h−1 and monotonically decreases with increasing LHSV for LHSV > 0.6 h−1. Then, each reforming efficiency always attains the maximum for LHSV ≈ 0.6 h−1 being independent of fuels. This suggests the common upper limit of LHSV for practically suitable operation.


2019 ◽  
Vol 20 (4) ◽  
pp. 61-66
Author(s):  
Halah M. Hussain ◽  
Abdulhaleem A.K. Mohammed

Hydroisomerization of Iraqi light naphtha was studied on prepared Ni-Pt/H-mordenite catalyst at a temperature range of 220-300°C, hydrogen to hydrocarbon molar ratio of 3.7, liquid hourly space velocity (LHSV) 1 hr-1 and at atmospheric pressure. The result shows that the hydrisomerization of light naphtha increases with the increase in reaction temperature at constant LHSV. However, above 270 0C the isomers formation decreases and the reaction is shifted towards the hydrocracking reaction, a higher octane number of naphtha was formed at 270 °C.


Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3196 ◽  
Author(s):  
Praepilas Dujjanutat ◽  
Arthit Neramittagapong ◽  
Pakawadee Kaewkannetra

In this work, hydro-processing was used as an alternative route for producing bio-hydrogenated kerosene (BHK) from refined bleached deodorized palm oil (RPO) in the presence of a 0.5 wt% Pd/Al2O3 catalyst. The Box-Behnken Design was used to determine the effects of reaction temperature, H2 pressure, and reaction time in terms of liquid hourly space velocity (LHSV) on BHK production. The kerosene selectivity was used as the response for staticial interpretation. The results show that both temperature and LHSV produced significant effects, whereas H2 pressure did not. The optimal conditions were found to be 483 °C, 5.0 MPa, and 1.4 h−1 LHSV; these conditions provided approximately 57.30% kerosene selectivity and a 47.46% yield. The BHK product had a good heating value and flash point. However, the mass percentage of carbon and hydrogen was 99.1%, which is just below the minimum standard (99.5%), according to the carbon loss by the reaction pathway to form as CO and CO2. Water can be produced from the reaction induced by oxygen removal, which results in a high freezing point.


2019 ◽  
Vol 70 (7) ◽  
pp. 2481-2484
Author(s):  
Rami Doukeh ◽  
Mihaela Bombos ◽  
Ion Bolocan

The kinetic study of the thiophene hydrodesulphurisation process was carried out for CoMo/gama-Al2O3 catalyst, at temperatures between 175 and 275 �C, pressure ranged from 30bar to 60 bar and the liquid hourly space velocity from 1h-1 to 4 h-1. For the reaction mechanism, the Langmuir-Hinshelwood-Hougen-Watson model (LHHW) was used and two kinetic models were proposed: the first model, that considered that H2 is adsorbed on a different type of active center than thiophene and the second model, that considered that the two reactants are adsorbed on the same type of active sites. The values obtained for the average relative error (ARE) and the correlation coefficient between the experimental and the calculated data (R2) indicate that the Langmuir-Hinshelwood model, describing the adsorption on two active sites, best describes the kinetics of the thiophene hydrodesulfurization reaction over CoMo/gama-Al2O3 tested catalyst.


2017 ◽  
Vol 68 (7) ◽  
pp. 1496-1500
Author(s):  
Rami Doukeh ◽  
Mihaela Bombos ◽  
Ancuta Trifoi ◽  
Minodora Pasare ◽  
Ionut Banu ◽  
...  

Hydrodesulphurization of dimethyldisulphide was performed on Ni-Co-Mo /�-Al2O3 catalyst. The catalyst was characterized by determining the adsorption isotherms, the pore size distribution and the acid strength. Experiments were carried out on a laboratory echipament in continuous system using a fixed bed catalytic reactor at 50-100�C, pressure from 10 barr to 50 barr, the liquid hourly space velocity from 1h-1 to 4h-1 and the molar ratio H2 / dimethyldisulphide 60/1. A simplified kinetic model based on the Langmuir�Hinshelwood theory, for the dimethyldisulphide hydrodesulfurization process of dimethyldisulphide has been proposed. The results show the good accuracy of the model.


Author(s):  
Yasuyoshi Takeda ◽  
Masaki Kusumi ◽  
Masaaki Kamizono ◽  
Toshio Shinoki ◽  
Hirochika Tanigawa ◽  
...  

The authors develop a small and simple steam-reforming reactor in a home-use size for such various heavy-hydrocarbons fuels as n-octane, n-decane, n-tetradecane and n-hexadecane in addition to n-dodecane, and measure the inside-temperature profile and the molar fractions of main gas components such as H2, CH4, CO and CO2. As a result, the authors successfully achieve suitable inside-temperature profiles. Namely, temperature almost-linearly increases in the downstream direction along a reactor, under such two conditions as 600–950 K at the upstream end of the catalyst-layer bed in the reactor and as less-than 1,070 K everywhere in the reactor. And, the authors reveal the effects of the liquid-hourly space velocity (LHSV) upon the molar fractions, a conversion ratio and reforming efficiencies for various heavy-hydrocarbons fuels. All the molar fractions, which agree well with thermochemical-equilibrium theory, are approximately independent of LHSV. The conversion ratio is about 90 % for LHSV ≤ 0.6 h−1, and monotonically decreases with increasing LHSV for LHSV > 0.6 h−1. Then, each reforming efficiency always attains the maximum for LHSV ≈ 0.6 h−1 being independent of fuels. This suggests the common upper limit of LHSV for practically-suitable operation.


2017 ◽  
Vol 68 (1) ◽  
pp. 35-39
Author(s):  
Raluca Elena Dragomir ◽  
Paul Rosca ◽  
Traian Juganaru

This paper presents options for increasing production of diesel fuel in a refinery by FCC light cycle oil (LCO) hydrotreating together with the straight run gas oil (SRGO). The experiments consist of hydrotreating mixtures of 10, 20% LCO and 90% and respectively 80% SRGO at 360, 380�C, two liquid hourly space velocity 0.9 h-1, 1.2 h-1, pressure 50 bar in the presence of two industrial catalyst type Co/Mo and NiMo. The research has focused on the influence of LCO/SRGO ratio, type of catalyst and hydrotreating conditions on diesel fuel quality compared with characteristics required by standard EN 590.


2014 ◽  
Vol 997 ◽  
pp. 16-19
Author(s):  
Xi Chao Chen ◽  
Yan Yang ◽  
Fang Hua Yin ◽  
Ran Xu ◽  
Long Yao Wang

The paper is about synthesizing the 2-ethylhexyl nitrate (2-EHN) with nitric acid and 2-Ethyl hexanol as raw materials and sulfuric acid as catalyst in a micro-channel reactor. The best synthetic conditions were determined under experiments: 1:2 for the mole ratio of nitric acid and sulfuric acid; 1:1 for the mole ratio of nitric acid and 2-Ethyl hexanol, the optimal liquid hourly space velocity is obtain as 4000h-1. In this condition, The yield and purity of EHN are Relatively high. This method is simple in process, mild conditions, safe, reliable and low energy consumption, providing the theory basis for industrialized production.


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