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Forecasting Lubricant Demand
Published in R. David Whitby, Lubricant Marketing, Selling, and Key Account Management, 2023
Hydrogen is currently produced on an industrial scale, for use in petroleum refining and chemical processes by one of two methods. Steam reforming of hydrocarbons (usually natural gas or coal) or carbon dioxide to produce synthesis gas, a mixture of hydrogen and carbon monoxide, is the precursor to making methanol and other chemicals. The hydrogen produced is also used to make ammonia, by reacting it with atmospheric nitrogen. Catalytic reforming converts petroleum refinery naphtha distilled from crude oil (typically having low octane ratings) into high-octane reformates, which are premium blending components for premium gasoline. The process converts n-paraffins into branched chain iso-paraffins and cyclic naphthenes, which are then partially dehydrogenated to produce high-octane aromatic hydrocarbons. The dehydrogenation also produces significant amounts of hydrogen gas as a by-product, which is fed into other refinery processes such as hydrocracking.
Catalytic Conversion Processes
Published in Marcio Wagner da Silva, Crude Oil Refining, 2023
The catalyst generally employed in the catalytic reforming process is based on platinum (Pt) supported by alumina treated with chlorinated compounds to raise the support acidity. This catalyst has bifunctional characteristics once the alumina acid sites are active in molecular restructuring and the metal sites are responsible for hydrogenation and dehydrogenation reactions.
Chemicals from Paraffin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Heavy naphtha from atmospheric distillation units or hydrocracking units has a low-octane rating, and it is used as a feedstock to catalytic reforming units. Catalytic reforming is a process of upgrading low octane naphtha to a high-octane reformate by enriching it with aromatic derivatives and branched paraffin derivatives. The octane rating of gasoline fuels is a property related to the spontaneous ignition of unburned gases before the flame front and causes a high pressure. A fuel with a low-octane rating produces a strong knock, while a fuel with a high-octane rating burns smoothly without detonation. Octane rating is measured by an arbitrary scale in which isooctane (2,2,4-trimethylpentane) is given a value of 100 and n-heptane a value of zero. A fuel’s octane number equals the percentage of isooctane in a blend with n-heptane.
Simulation and energy optimization of a reformate stabilizer unit in a petrochemical plant
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Ali Jalali, Mojtaba Shafiee, Davood Iranshahi, Amir H. Mohammadi
Naphtha is transformed into reformate by catalytic reforming (le Goff et al. 2017; Lok et al. 2018). This process includes rebuilding low octane hydrocarbons in naphtha to high-value gasoline components with high octane without a change in boiling point interval. Naphtha and reformate are complex mixtures that contain paraffins, naphthenes, and aromatics. The main aim of catalytic reforming is to increase the octane number of naphtha feed to a level that produces an appropriate reformate product as gasoline cut. The number of octane shows the resistance of gasoline in the engine’s cylinder at the time of combustion of air and gasoline mixture (Singh et al. 2017). Reformate can be stabilized by removing impurities such as hydrogen, sulfur, light gasses, and liquid gas petroleum (Ladkat and Tiwari 2017; Rastelli et al. 2017). Stabilizing the reformate in naphtha stabilizer will decrease the vapor pressure (Kianfar et al. 2015, Xin et al. 2018). Basically, a stabilizer is a distillation used for removing small amounts of light components from a product. The main goal of distillation is to separate materials with different vapor pressures at a certain temperature. Here, distillation is referred to as a physical separation of a component or several segments with different boiling points (Jiang et al. 2018; King 2013; Yang et al. 2017). Therefore, developing a suitable algorithm for process simulation is very important. Simulation is a key stage in optimization for problems of a distillation tower. Precision, speed, and convergence properties are three important factors for selection of a suitable simulation method (Hashim and Jassim 2014).
Catalysis by nanoscale gold (Au/MOx): A. Rational methods for preparation of small metallic gold particles
Published in Petroleum Science and Technology, 2019
In the catalytic reforming process, the feedstock is first pretreated with hydrogen to remove chlorine, sulfur, and nitrogen compounds (as HCl, H2S, and NH3, respectively), which can poison the catalyst. The desulfurized feedstock is then heated to vapor and passed over a stationary bed of noble metal catalysts, such as Pt, Mo, or Re, onto an acidic-function support. In the reformer-reactor, the dehydrogenation reactions produce primarily high-octane aromatics, and branched paraffins or isoparaffins are formed as another product of dehydrogenation of linear alkanes. Fluidized catalytic cracking is the most important refining process considered here. Crude oil of a defined feedstock composition is cracked with Re catalyst loaded onto a crystalline aluminosilicate matrix. The products consist of light gases (C4, liquefied petroleum gas), C5+ gasoline boiling range hydrocarbons, diesel fuels, aviation turbine fuels, and light and heavy gas oils. The yield pattern is determined by complex interaction of feed characteristics and reactor conditions that determine severity of operation. It appears that the zeolite surface area (Z), and the and the matrix surface area (M), and the Z/M ratio are the important determinants of the product yields and severity of process operation (T, cat to oil ratio). As Z/M ratio decreases, the zeolite surface area decreases while the matrix surface area increases simultaneously, at a given constant total surface area (Ziebarth and Schiller 2009). For all catalysts, as the percentage of synthetic crude in the blend is increased, the feed is more difficult to crack, requiring a higher cat/oil ratio and producing higher coke. In addition to the higher cat/oil and coke yield, the yields show significant increases in wet and dry gas as well as a decrease in gasoline with increasing amounts of synthetic crude in the feed blend. The addition of synthetic crude to the feed blend makes the crude more difficult to crack. The gasoline composition also changes notably with the feed, and the quality shifts to a higher octane number, due to more aromatics.
Operation parameters effect on yield and octane number for monometallic, bimetallic and trimetallic catalysts in naphtha reforming process
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Catalytic reforming is a chemical process utilized in petroleum refineries to convert naphtha, typically having low octane ratings, into high octane liquid products, called reformates, which are components of high octane gasoline. The reformate produced includes high-value aromatics for the petrochemical industry such as benzene, toluene, and xylenes (BTX). (Turaga and Ramanathan 2003). The most commonly used type of the reforming process is the semi-regenerative catalytic reformer where about 60% worldwide is using this process (Al-Saraji, Rahman, and Al-Hassani 2013). Catalytic reforming process will continue to play an important role in meeting the world’s demands for high octane gasoline, petrochemicals and hydrogen hence the need to embark on continued improvement of the process. Okonkwo, Aderemi, and Olori (2017), examined the effect of temperature on the regeneration of Pt/Al2O3 catalyst employed in semi-regenerative fixed bed process. Hydrogen will be a requisite energy source in the upcoming future. In the refineries, Hydrogen as the main byproduct is highly valued for its use in hydrotreating, hydrocracking, and other hydrogen consuming processes in the refinery. Hence, attempts are made to enhance hydrogen production rate and its purity in refineries. Due to the importance of hydrotreating and hydrocracking techniques, studies should be focused on upgrading naphtha reforming processes, which supply a large quantity of required hydrogen for refineries. In the past decade, given its widespread economic importance, researchers have focused to find new ways for upgrading naphtha reforming process (Gupta, Ibrahim, and Al Shoaibi 2016; Rana 2017). Catalytic reforming processes are commonly classified, according to the frequency and mode of catalyst regeneration, into (1) semi-regenerative, (2) cyclic, and (3) continuous. The major difference between the three processes is the requirement to shut down for catalyst regeneration, (Babaqi et al. 2016; Talaghat, Roosta, and Khosrozadeh 2017). The semi-regenerative naphtha reformer is the oldest type where reactions are carried out in three or four adiabatic fixed-bed reactors in series, each of which is equipped with a pre-heater. A large number of reactions occur in catalytic reforming. During catalytic reforming long-chain hydrocarbons are rearranged through isomerization, hydrogenation, dehydrocyclization and dehydrogenation reactions. Some of these reactions are desired because of increasing octane number of gasoline and also the purity of the produced hydrogen, and some of them are undesired due to decreasing them. These reactions occur on acid and/or metal sites and they demand the use of bifunctional catalysts (Seif Mohaddecy and Sadighi 2014; Sukkar, Raouf, and Hamied 2013). The metals used with Pt/Al2O3 catalyst other than Re are Sn, Ge, and Ir. These additives modify the activity, selectivity, and stability of the catalyst. These metals are used as a bimetallic catalyst. This type of bimetallic naphtha reforming catalyst makes a big leap forward in the technology of reforming catalyst and it improves its properties (Carvalho et al. 2004; Silvana et al. 2008).