Design parameters for a hydro desulfurization hds unit. In a refinery, the hydrocracker upgrades vgo through cracking while injecting hydrogen. Hydrotreater optimisation with welded plate heat exchangers. The discussion above shows that an important part of the nht unit design is to understand the source of the naphtha feed and makeup hydrogen to be able to adequately quantify the expected contaminant levels, as well as trace elements that may not set the severity of the unit but will. Most facilities include at least three hydrotreating units for upgrading naphtha, middle distillates, gas oils, intermediate. In a petroleum refinery, a catalytic reforming unit cru is set up to increase the octane number of naphtha through reforming reactions. Design capacityof unit was 12000 bpsd, but because of increasing. 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. C, the unit is scheduled for shutdown and catalyst replacement. The naphtha hydrotreating process is also important to pretreat naphtha for downstream units, like paraffin isomerization and catalytic. Coker naphtha hydrotreating technology hydroprocessing. Phes used in reactor feedeffluent fe service significantly reduce project. A method for startingup a naphtha fraction hydrotreating reactor which subjects a naphtha fraction obtained in a fractionator by fractional distillation of hydrocarbon compounds produced by a fischertropsch synthesis reaction to hydrotreating, the method comprising.
Pdf revamp of naphtha hydrotreating process in an iranian refinery. Spivey, in new and future developments in catalysis, 20. As coke deposits on the catalyst, reactor temperature must be raised. Unocal hydrotreating and hydrocracking reactor replacement. The naphtha hydrotreating process is also important to pretreat naphtha for downstream units, like paraffin isomerization and catalytic reforming, where severe.
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. A recent study for a grassroots 30,000bsd hydrotreater that can produce ultralow sulfur diesel ulsd helped assess the critical process design issues for meeting future ulsd requirements. Modeling a catalytic reactor for hydrotreating of straightrun gas oil blended with fluid catalytic cracking naphtha and light cycle oil. At this point, any additional throughput requires the reactor temperature to be reduced and. Demonstration of loading, reaction and unloading in a production scale rotating bed reactor duration. The modelling of reactor, separation and heat recovery system for diesel hydrotreating processes is discussed, and a novel optimisation framework is developed for the design of complex refinery. It has been arts experience that the first course of action by the refining community is to attribute the problem to catalyst performance. Gasoline upgrading purpose increase the quality of feed stocks of the same. General manager, process department, refinery technology. Dynamic modeling and simulation of catalytic hydrotreating.
Hyd ro t r eater optimisation with welded plate heat exc h. Design of laboratory hydrotreating reactors scaling down. Dht will typically perate at around psig reactor pressure and an lhsv of1 to meet ulsd specs. Removal of metals, usually in a separate guard catalytic reactor when the organometallic compounds are hydrogenated and decomposed, resulting in metal deposition on the catalyst pores e. The single reactor and single separator hydrotreater design above is typical. Reactor and reaction engineering play a vital role in petroleum and chemical processing. Using optitrap materials, we can design a topbed grading system. Removal of olefins, sulfur, and other contaminants from naphtha streams to prevent poisoning and degradation of catalysts in. Hydrodesulfurization an overview sciencedirect topics. Among all the available hydrotreating reactor technologies, fixedbed reactors are the most. The old reactor internals had a poor performance with high radial temperature spread. Mbpd straightrun sr naphtha hydrotreater nht complete with a recycle compressor from an adjacent idle reformer.
The reactor replacement work involved installation of three new reactors in a conventional. Klm technology group operating manuals light hydrocarbon kerosene hydrotreater operating manuals page 2 of 87 rev. Metals the metals contained in the naphtha feed are arsenic, lead, and to a lesser degree copper and nickel, which damage the reforming catalyst. In the presence of the metaloxide catalyst, the hydrogen. Effect of reactor inlet temperature in a hydrotreater.
The naptha hydrotreater prepares feedstock for downstream reforming or isomerization. This implies that the coker naphtha hydrotreater needs to be operated at high severity to meet the required product specifications on nitrogen. If the hydrogen pressure is too low for the required duty at any position within the reaction. Regenerative platforming low platinum regeneration once a year made naphtha octane improvement accessible to all refiners. The reactor contains a cobaltmolybdenum or nickelmolybdenum catalyst system that converts. Naphtha hydrotreating is an essential step for refiners to produce cleaner gasoline from different feedstocks.
Require high concentration of hydrogen at reactor outlet. Reactor conditions for naphtha hydrotreating unit are around 400500. What happens to the catalyst if water goes to naphtha or diesel hydrotreater reactor along with feed which is having nickel molybdenum catalyst. Criterion is a worldleading supplier of naphtha hydrotreating catalysts, the key to the effective removal of sulphur and nitrogen. The liquid effluent for the reactor is introduced to a fractionators for product separation. The design of a laboratory reactor for hydrotreating processes i. Design parameters for a hydro desulfurization hds unit for.
Hydrodesulfurization and demetallization occur simultaneously on the active sites within the catalyst pore structure. The expensive platinum based catalyst used in the reformer is sensitive to poisoning by such impurities. Pq optimization services,3418 clear water park drive, katy, tx 77450. This yields a high volume of highquality diesel and kerosene product. Naphtha hydrotreating reactor catalyst bed grading youtube. Metals the metals contained in the naphtha feed are arsenic, lead, and to a lesser degree copper. The purpose of removing the sulfur, and creating products such as ultralowsulfur diesel, is to reduce the sulfur dioxide so 2 emissions that result from using those. Us20110207978a1 method for startingup naphtha fraction. Naphtha hydrotreating to remove the impurities so that the hydrotreated naphtha can be introduced to the catalytic reformer. Are there any differences between a naphtha hydrotreater.
The important effect of hydrogen is the minimization of coking reactions. Hydrocracking processes distillate hydrocracking is a refining process for conversion of heavy gas oils and heavy diesels or similar boilingrange heavy distillates into light distillates naphtha, kerosene, diesel, etc. Reactor selection and design are the basis of economical and safe operation. Avoid mercaptan recombination with naphtha hydrotreating.
Pdf hydrotreating of naphtha hds is one of the important units in crude oil. Nonetheless, the facilitys catalyst vendor should be contacted to help assist in solving the hydrotreater s performance issues. As a result the diesel hydrotreater usually operates at a higher pressure and lower lhsv than a naphtha hydrotreater. The mixed feed is then heated and then fed to the reactor, which contains a cobaltmolybdenum or nickelmolybdenum catalyst to convert contaminants such as sulphur, nitrogen, oxygenates and. Proper design and operation of a naphtha hydrotreater combined. Hydrotreating is applied to a wide range of feedstock, from naphtha to. Unisim design suite hydroprocessing reactors honeywell. Handling the higher content of naphtha in crude, as well as the lower content of. Reactors designed with adequate thermocouple coverage at each bed level provide a more accurate determination of radial temperature spreads. What happens to the catalyst if water goes to naphtha or. Hydrotreating is the reaction of organic compounds in the presence of high pressure hydrogen to remove oxygen deoxygenation along with other heteroatoms nitrogen, sulfur, and chlorine. Even when operating with only two reactors, these three. During normal operation, typically water present is the reactor feed will be vapor phase and which will lower the h2 partial pressure in the reactor.
The sulfur content of coker naphtha can be 20 times higher than in straightrun naphtha. This is in contrast to the fcc, which uses the same feed vgo but produces more and betterquality gasoline the hydrocracker is particularly. The aim of this article is to acquaint the reader with the interaction between reactor design selection and the characteristics of the chemical reaction of interest. The purpose of a hydrotreater unit is primarily to remove sulfur and other contaminants from intermediate streams before blending into a finished refined product or before being fed into another refinery process unit hydrotreaters have become increasingly important as sulfur limits have been lowered in. Speight, in heavy oil recovery and upgrading, 2019. Hydrotreating is carried out in the presence of a catalyst to remove oxygen.
The coker naphtha hydrotreater needs to run under severe operating conditions to meet product specifications. Study outlines optimum ulsd hydrotreater design oil. Catalytic reforming of heavy naphtha, analysis and simulation diyala journal of engineering sciences, vol. Heavy naphtha 230 to 400 of 100 to 200 oc uses feed for catalytic reforming unit feed for aromatics production c5 400 of 200 oc kerosene hydrotreater naphtha splitter gas oil hydrotreater naphtha hydrotreater wild naphtha wild naphtha straightrun naphtha crude atmospheric distiller.
Hydrodesulfurization hds is a catalytic chemical process widely used to remove sulfur s from natural gas and from refined petroleum products, such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils. For proper design and simulation of hdt reactors, kinetic. Cetane improvement by 10 units reactor design based on inhouse. In a mercaptan recombination case study where sr naphtha was processed at 8. The naphtha feed is mixed with hydrogen rich recycle gas.1459 615 520 1006 580 787 1037 410 630 296 1022 478 760 138 1544 262 735 1432 1479 426 52 620 1267 482 404 429 500 699 1360 220 1237 849 944