The nht unit prepares feedstock for downstream reforming or isomerization units that have sensitive noble metal catalyst. David krenzke, regional manager of hydrotreating technical services for. It is mixed with hydrogen gas coming from a cat reforming unit or hydrogen plant. Pretreatment of hydrocracking feed to reduce sulphur, nitrogen and aromatics. Design parameters for a hydro desulfurization hds unit. Visbreaker gas oil blend stocks for diesel, fuel oil naphtha, middle distillates. After the naphtha hydrotreating unit, naphtha is sent to an isomerisation unit or a catalytic reformer unit, which often use reforming catalysts. Petroleum naphtha naphtha is a complex mixture of liquid hydrocarbons, with boiling ranges of about 40 to 140 c and with vapor pressures of about 0. Process work of a naphtha hydrotreating unit proses industri. Crude distillation, catalytic cracking, delayed coking and visbreaking units produce naphtha with low octane number and contain deferent types of contaminants at the same time. Nht naphtha hydrotreating unit is a functional to perform the decomposition components of sulfur, oxygen, nitrogen, and metal compounds. Proper design and operation of a naphtha hydrotreater combined.
Feed to a distillate hydrotreating unit may be any blend or combination of straight run distillate. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Network of dividing wall columns in complex process units. The naphtha hydrotreating process is also important to pretreat naphtha for downstream units, like paraffin isomerization and catalytic reforming, where severe specifications are required and catalysts used are very sensitive to impurities. A commonly used hdscatalyst is molybdenumnickel on alumina support. Improvement of the operation cycle time of a naphtha hydrotreating. The chemical composition of a gasoline blend consists of hydrocarbon chains. Dividing wall columns in naphtha hydrotreating nht units as shown in figure 2 and figure 3, the stabilizer can be replaced with a proprietary top dividing wall column. Pdf hydrotreating of naphtha hds is one of the important units in crude oil refineries in whichcompounds such as sulfur, nitrogen, oxygen. Revamp of naphtha hydrotreating process in an iranian refinery. The naphtha feed enters the unit through charge pump piol.
Conventional naphtha hydrotreating and isomerization process scheme. Purpose of the naphtha hydrotreating unit is to remove sulphur and nitrogen compounds. Naphtha hydrotreating is an essential step for refiners to produce cleaner gasoline from different feedstocks. It contains many different compounds such as paraffins, isoparaffins, olefins. The feed of the naphtha hydrotreating unit is a blend of different raw naphtha feeds. Hydrotreating of naphtha hds is one of the important units in crude oil refineries in whichcompounds such as sulfur, nitrogen, oxygen and metal are removed.
The heated feed hydrogen mix next enters the desulfurization reactor viol at the top. An equivalent naphtha is obtained as a product, requiring conventional refining. Naphtha cut which is obtained from crude is typically defined, as c5140 in a refiners lingo but the end point of naphtha that is found in modern refineries can be as high as 180 degc. Sulfur and nitrogen compounds present in naphtha cut from atmospheric distillation column can deactivate the catalyst and must be removed prior to catalytic reforming. Sulphur, metal, polyaromatics and conradson carbon removal from vacuum gas oil vgo to be used as fcc feed. Naphtha is hydrotreated for removal of metal and sulphur. Naphtha hydrotreating reactor catalyst bed grading youtube. Most reforming catalysts contain platinum as the active material. Pdf revamp of naphtha hydrotreating process in an iranian refinery.