Hydrotreating is a process to reduce sulfur, aromatics, nitrogen, oxygen and metals while enhancing the combustion quality, density and smoke point of distillates. Effect of organic nitrogen compounds on hydrotreating and hydrocracking reactions article in catalysis today 1091. Hydrocracking unit refinery plant petroleum refining. A niche market has developed for mild hydrocracking of lco as it takes a product typically destined for fuel oil and converts it to a more profitable product, lowsulfur 50 ppm or ultralow sulfur diesel product 10 ppm sulfur or less. Tk41 is available in ring shape and has been developed as a firststage guard catalyst for use in grading systems where arsenic pickup is needed. Effect of organic nitrogen compounds on hydrotreater. Hydrocracking is a catalytic cracking process assisted by the presence of an elevated partial pressure of hydrogen gas. Experiments on the hydrocracking of feedstocks containing 0. Am10154 impact of processing heavy coker gas oils in hydrocracking units presented by. Effect of nitrogen compounds on the hydrocracking of heavy. It takes heavy oil and cracks it into gasoline and kerosene jet fuel. Hydrocracking is an important source of diesel and jet fuel source. Nitrogen applications oil and gas exploration and production midstream and transmission. The composite zeolites were used as the acid components of hydrocracking catalyst supports.
Catalyst testing for hydrocracking and hydrotreating. Hydrocracking, processing heavy feedstocks to maximize high quality distillate fuels. Unlike a hydrotreater, hydrocracking uses hydrogen to break cc bonds hydrotreatment is conducted prior to hydrocracking to protect the catalysts in a hydrocracking process. The hydrocracker yields a high volume of kerosene and light gasoil distillate of good quality high cetane and low sulfur.
Chemical processing how oil refining works howstuffworks. During hydrotreatment, hetero atoms sulfur, nitrogen and metals are removed from distilled crude oil fractions and unsaturated hydrocarbons get saturated. These feed blends are processed in hydrocracking units with various objectives and flow schemes. The stacked beds comprising hydrotreating catalyst as the top layer, hydrocracking catalyst based on amorphous silicaalumina as the interlayer and hydrocracking catalyst based on usy zeolite as the bottom layer were tested in hydrocracking of mixed feed containing straightrun vgo, heavy coker gas oil, aromatic extract and petrolatum. Sulphur, metal, polyaromatics and conradson carbon removal from vacuum gas oil vgo to be used as fcc feed. These reactions reduce the sulfur and nitrogen contents of the oil and. The entire output from this reactor is then injected into a second reactor containing a hydrocracking catalyst, which helps the reactions that crack apart the hydrocarbons while saturating them with hydrogen.
The heavier feed components in the blends cover heavy coker gas oil hcgo, heavy vacuum gas oil hvgo, light cycle oil lco and deasphalted oil dao. In other words, the main application is to upgrade vacuum gas oil alone or blended with other. Hydrocracking is a process of catalytic cracking in the presence of hydrogen. Role of catalyst in hydrocracking of heavy oil journal. Us7763163b2 process for removal of nitrogen and poly. The hydrocracking reactor effluent goes through gas liquid separation and then to the fractionator. The process is done for medium distillates like heavy naphtha, kerosene and diesel through hydrodesulfurization hds reactors. The results show that the content of basic nitrogen compounds has influence on hydrocarbons cracking during cgo fcc reaction, but it is not as obvious as reported before. The selective removal of nitrogen containing compounds from oil and oil fractions is of interest because of the. Hydrogen is used to purify the hydrocarbon stream from sulfur and nitrogen. A hydrocracking unit, or hydrocracker, takes gas oil, which is heavier and has a higher boiling range than distillate fuel oil, and cracks the heavy molecules into distillate and gasoline in the presence of hydrogen and a catalyst. Any sulfur and nitrogen present in the hydrocracking feedstock is, to a large extent, hydrogenated to form gaseous hydrogen sulfide h2s and ammonia nh3, which are subsequently removed. The deactivating effect of nitrogen when present to the extent of 0.
Under mild process conditions, gas oil hydrocracking catalysts may also be used. At first feedstock is sent to the 1st hydrocracking reactor where fixedbed catalysts convert sulfur and nitrogen compounds. The hydrocracker is particularly valuable in a refinery that is trying to maximize diesel production and reduce residual fuel oil. Hydrocracking of residual oils mainly increases the production of high quality middle distillates for blending into jet and diesel fuels while reducing the volume of low value, high sulfur residual fuel oil. A hydrocracking process is described wherein heavy hydrocarbon oils having from about 10 to 50% boiling above 1,000sup 0f and containing appreciable amounts of sulfur, nitrogen, and metalcontaining compounds as well as asphaltenes are converted into a minor fraction of low sulfur residual fuel oil and a major fraction of low sulfur gasoline.
The basic nitrogen compounds in coker gas oil cgo narrow fractions were enriched, and their influences on hydrocarbons during fluid catalytic cracking fcc were investigated. Tk41 has very high affinity for arsenic trapping in vgo and gas oil services, where it is also able to trap nivsi. Am10154 impact of processing heavy coker gas oils in. Hydrocracking is an important source of diesel and jet. Using this analytical data, the mass balance was closed based on mass flow rates.
Nitrogen fluid pumping can provide cost, performance, and environmental. Nimousyalumina catalysts with different zeolite content. Mild hydrocracking of vacuum gas oil produces lighter products mainly in the. It uses high pressure, high temperature, a catalyst and hydrogen to crack heavier feedstock into lighter, more valuable products.
Any sulfur and nitrogen present in the hydrocracking feedstock are, to a large extent, also hydrogenated and form gaseous hydrogen sulfide h 2 s and ammonia nh 3, which are subsequently removed. Hydroprocessing comprises of hydrotreating and hydrocracking. Hydrotreating unit refinery plant petroleum refining. This configuration uses recycle for optimization of yield and processing severity. The similarities are that both treat petroleum fluid streams, both generally use some type of catalyst, that both use high partial pressures of hydrogen, and both usually involve some type of hydrogenation op. Nitrogen is used to support oil and gas exploration, extraction, and processing.
Conversion, product yields, and product quality over an industrial hydrocracking catalyst system g. Kinetics of hydrocracking and hydrotreating of coker. A hydrocracking unit, or hydrocracker, takes gas oil, which is heavier and has a higher boiling range than distillate fuel oil, and cracks the heavy. It is used for feedstock that are difficult to process either by catalytic cracking or reforming. Pretreatment of hydrocracking feed to reduce sulphur, nitrogen and. Pdf characterization of nitrogen and sulfur compounds in. These gas oils are heavier than distillate fuel oil, and they have a higher boiling range as well. Hydrocracking is used for feedstock that are difficult to process by either catalytic cracking or reforming, since these feedstock are characterized usually by a high polycyclic aromatic content andor high concentrations of the two principal catalyst poisons, sulfur and nitrogen compounds. During hydrocracking heavier hydrocarbon molecules are.
The flowscheme is designed to assure that high quality product is produced in terms of ulsd with a cetane index over 55. With hydrocracking it is possible to convert an aromatic compound to a paraffinic compounds without any loss of carbon, as shown in figure 7. Kinetics of hydrocracking and hydrotreating of coker and. The removal values of sulfur and total nitrogen, basic nitrogen, and nonbasic nitrogen obtained under optimum.
The conversion of gas oil to middle distillate during hydrotreating was correlated with sulfur content and polyaromatic hydrocarbon content. A hydrocracking unit takes heavy gas oil from the atmospheric tower, the vacuum tower, the fccu, and the coking units as a feedstock. Us6547956b1 hydrocracking of vacuum gas and other oils. Consequently, the flow scheme for a mild hydrocracking unit is virtually identical to that for a vacuum gas oil desulfurizer. Like hydrotreating, hydrogen is used to purify the hydrocarbon stream from sulfur and nitrogen. A major issue encountered in hydrotreating and hydrocracking reactions. This process can also be used to produce low sulfur fuel oil. The hydrocracking hc process is able to remove the undesirable aromatic compounds. The mild hydrocracking process uses operating conditions similar to those of a vacuum gas oil desulfurizer to convert vacuum gas oil to significant yields of lighter products. The product gas streams were analysed on the basis of online gas chromatography and thermal conductivity detection hydrocarbons up to c20, h2 and h2s and the liquid offline samples based on total sulphur nitrogen, densityapi and simulated distillation. Twostage hydrocracking of gas oils involves a complex set of. Citric acidtreated zeolite y cy and zeolite beta were mechanically mixed to obtain composite zeolites cybeta with various zeolite beta contents.
The process includes a first hydrogenation reaction in the presence of multiple hydrogenation catalyst beds which is limited to the hydrogenation level needed for the removal of sulfur and nitrogen and for aromatic. This catalyst accelerates the reactions that remove sulfur and nitrogen from the hydrocarbon and open up and saturate aromatics rings. Its flexibility with respect to production of gasoline and middle distillates, ability to handle a wider range of feedstock like cycle oils from other cracking units does not yield any coke as byproduct better conversion of the gas oil and residues into useful products. Seppro systems builds and designs crude oil topping units that use atmospheric distillation to produce lpg, agd, atmospheric gas diesel, kerosene, avgas, or resid. Hydrocracking increases the degree of saturation of the products which.
The unconverted material is low in sulfur, nitrogen, and other impurities and is used as either feed for fluid catalytic cracking units fccu or a fuel oil blending component. Thus, nimomcm41 catalysts showed higher activity than nimoasa and nimousy for the onestage hydrocracking of a vacuum gas oil feed containing 2. In other words, the main application is to upgrade vacuum gas oil alone or blended with other feedstocks lightcycle oil, deasphalted oil, visbreaker of coker gas oil producing intermediate distillates naphta, jet and diesel fuels, lowsulfur oil and extraquality fcc feed. Therefore the difference of isomerization degree between gasoil and kerosene is. The hydrocracking hc process is able to remove the undesirable aromatic compounds from petroleum stocks producing cleaner fuels and more effective lubricants. The physical and chemical properties of the supports and catalysts were analyzed by n2 adsorptiondesorption, xrd, sem, and nh3tpd. Hydrocracking is done with heat, catalyst and hydrogen. Light naphtha crude oil desalter atmospheric distillation. The purpose of this unit is to reduce the sulphur, nitrogen, and aromatic hydrocarbons to acceptable levels to allow subsequent processing of the gas oil in a conventional refinery catalytic cracker or hydrocracker. Product selectivity during hydrotreating and mild hydrocracking of. Hydrocracking process takes place in a hydrogenrich atmosphere at elevated temperatures of 260 to 425 degrees celsius and pressures of 35 to 200 bars. The result is that the hydrocracking products are essentially free of sulfur and nitrogen impurities and consist mostly of paraffinic hydrocarbons. Effect of organic nitrogen compounds on hydrotreating and.
The typical application of this technology is fcc feed pretreatment. Hydrocracking, gas oil downstream barrels per stream day cat hydrocracking, residual downstream. Hydrocracking, processing heavy feedstocks to maximize. Hydrocracking is a catalytic cracking process assisted by the presence of added hydrogen gas. Hydrocracking of the gas oil in the second stage of reaction followed a langmuirhinshelwood rate expression based on the inlet concentration of total nitrogen. The feeds that can be processed in the vgo unionfining process include straightrun vacuum gas oil, heavy coker gas oil and visbreaker gas oil.
Hydrocracking is a process that breaks down complex hydrocarbon molecules into simpler ones by using a catalyst and an elevated partial pressure of hydrogen gas. Hydrocracking is an important source of diesel and jet fuel today in. In addition to the liquid products hydrocracking yields light gases that can be used as fuel for the refinery or as petrochemical feedstock. This is an established and reliable method for transforming low value heavy oil.
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