The goal of Catalytic reforming process is to convert heavy naphtha, which contains high levels of naphthenes, into a high-octane reformate. This reformate is very low in sulfur and is an important product for blending in gasoline. This process produces hydrogen that can be used for hydro treating and hydro cracking processes. This hydrogen is used to hydrotreat the naptha feedstock. This needs to be done to protect the platinum catalyst from poisoning by sulfur or nitrogen species. Even with the hydrogen usage catalysts are still deactivated by coke deposition. The commercial catalytic processes are identified based on the type of catalyst regeneration that is used. The first type of reforming process that was used commercially is called semi-regenerative. This process was first used in 1949. These reactors need to be shut down every 3 to 24 months because the catalysts need to be regenerated because the catalysts are deactivated by coke deposition. The second type of catalytic reforming process is called cyclic. It was first introduced in 1960 and involves a swing reactor. Three of the four are in operation at one time. They use the extra reactor when one is offline for catalyst regeneration. The third type of catalytic reforming process is called continuous. This type of process was introduced in 1971. The catalyst is removed and replaced without stopping the process. This allows the catalysts to maintain a high level of activity, although this process is very expensive. There are three types of processes within catalytic reforming are Alkylation, polymerization, and isomerization. Alkylation combines light iso-paraffins with olefins to produce very high molecular weight iso-paraffins to blend with gasoline. Polymerization combines propenes and butenes to also produce higher olefins with high octane numbers to blend with gasoline. Isomerization has been used since the need for lead free gasoline has been relevant. This process isomerizes n-butane to iso-butane. Then also uses alkylation to produce high octane gasoline stocks.

The catalytic reforming process was somewhat of a “late addition” to the whole petroleum-refining scene. The 1940’s and 1950’s opened up a new world of high compression engines (automobiles & aircraft) and families with multiple automobiles, so naturally the demand for high octane number gasoline skyrocketed. Catalytic reforming solved this issue by taking the heavy straight run naphtha fractions from the atmospheric distillation tower and converting it into a high octane product that proved to be the main fraction of the gasoline blending pool. Beyond the production of high octane number reformates, this process also yields high amounts of hydrogen, which can be separated out and transferred to other processes in the refinery such as hydrocracking and hydrotreating.

This process is fairly complex, in terms of the chemistry, compared to other refining processes. Since this process uses catalysts that contain platinum, the feedstock must first be hydrotreated to eliminate the probability of poisoning. There are desired reactions and undesired reactions that could take place all depending on four variables such as temperature, pressure, H₂/hydrocarbon ratio, and space velocity. The overall reactions that should take place are naphthenes converted to aromatics and n-paraffins converted to i-paraffins, but the four specific reactions are dehydrogenation, dehydroisomerization, dehydrocyclination, and isomerization. Each has their own range of octane number increases but the conditions in which these reactions are favored are all similar. A reactor with high temperature, low pressure, and low H₂/hydrocarbon ratio favors these reactions against undesired hydrocracking. The main problem with controlling conditions is that hydrocracking AND the desired reactions both thrive in a reactor with low space velocity; this aspect of the process is where the refinery has to control the activity of the catalysts and the balance of acidic versus metal sites to have high yield and high quality results. Despite the specifics of these reactions and refinery’s firm grasp of the chemistry of each particular process, regulations on limiting benzene and aromatics in automobile gasoline have limited the catalytic reforming process in the United States.

Catalytic reforming is a process which is born out the the necessity for high octane fuels which are used in transportation such as gasoline and aviation fuel.. This process takes the low octane straight run naphtha that is rich in naphthenes into high octane and low sulfur fuel which is used heavily in gasoline. Using this process a higher yield of gasoline can be achieved. In order to do this a few chemical reactions which increase the octane number of naphtha, convert the naphthenes to aromatics, and insomerize n-paraffins to i-paraffins must be completed. The catalysts used to bring these reactions to completion are generally platinum, palladium, or bimetallic formulation of platinum with Iridium or Rhenium with alumina. The process creates a large volume of hydrogen, which is a very valuable bi-product because it is in high demand for hydro-treating and hydro-cracking processes. The catalytic reformer is fed by the heavy naphtha line from the naphtha splitter. The naphtha splitter is fed by the straight run naphtha. The most desirable chemical reactions in the catalytic reforming process is dehydrogenation of naphthenes to aromatics, dehydroisomerization of alkyl-c5-naphthenes, Dehydrocyclization of n-paraffins to aromatics, and isomerization of n-alkanes to i-alkanes. These reactions increase the Research Octane Number (RON) from 75 to 110, 83 to 100, 0 to 110, and -19 to 90 respectively. 
All of these reactions except for the isomerization of n-alkanes produces hydrogen. If sufficient hydrogen is not produced coking my begin.

The catalytic reforming process is not without its limits. The United States and Europe limits the amount of benzene and other aromatics which can be found in gasoline. Because these compounds are carcinogenic and are harmful to the environment in many cases, catalytic reforming is limited. The high demand for high octane fuels and the hydrogen by product makes the process very valuable to refineries despite the production of aromatics.

Catalytic reforming is a necessary chemical process used in the petroleum refining industry which takes in straight run naphtha or partially treated light straight run naphtha, depending on the process, as a feedstock and converts it into high octane reformate and gasoline products. The earliest catalytic conversion processes date back as far as the 1930’s, however they have been continually improved upon since then with advances in techniques, catalysts, and yields to meet governmental product requirements. There are several different processes that are designated into classifications based on how their individual catalyst regeneration systems work. Those classifications are: semi-regeneration, cyclic regeneration, and continuous regeneration. Older catalytic reforming processes are typically semi-regenerative while cyclic and continuous regeneration processes are newer more advanced strategies.

Semi-regenerative methods, while useful, can be problematic because they must be turned off on a scheduled basis for the regeneration process to take place. These scheduled outages mean that the refineries cannot generate products and are therefore losing money while the units are offline. Cyclic units sought to resolve some of these issues by introducing another reactor to a two or three reactor system so that while one is turned off for regeneration the others could continue running and producing high octane fuels. The most up-to-date practices use continuous regeneration which requires no shutdown time because catalysts are momentarily removed from the reaction process, regenerated, and then introduced back in to continue the transformation of low octane feedstocks to high octane products. Continuous processes appear to be the best way to go except that they are the most expensive and most technically involved of the three methods.

Besides the regeneration methods, catalytic reforming processes, such as alkylation, dealkylation, polymerization, isomerization, and disproportionation¹, have their own advantages and disadvantages as well. Sulfur is a major issue for catalysts because it will poison the catalysts causing them to be unable to function so hydrogenation must occur prior to any of these catalytic reforming processes taking place to remove sulfur. Dehydrogenation and dehydrocylcinization as overall processes can also be problematic because they can create aromatic compounds which are regulated by the U.S. government due to their nature as carcinogens. The procedure of alkylation has an advantage over other practices in this respect because it does not produce any aromatic compounds which is why it is favored in use over other reforming types.² Alkylation is not without its drawbacks though, while it yields no aromatics alkylation does require the use of highly concentrated acids, such as hydrofluoric or sulfuric acid¹. Acids such as these can be dangerous to human health as well as the environment ^{3 4}.

1. “CIEC Promoting Science at the University of York, York, UK.” Cracking and related refinery processes. N.p., n.d. Web. 10 July 2014. <http://www.essentialchemicalindustry.org/processes/cracking-isomerisation-and-reforming.html>.
2. Eser, Semih. “Alkylation.” FSC 432: Petroleum Processing. N.p., n.d. Web. 12 July 2014. <https://cms.psu.edu/section/content/default.asp?WCI=pgDisplay&WCU=CRSCNT&ENTRY_ID=F20C6357261A4AE2A750C141B
3. “Hydrogen Fluoride (Hydrofluoric Acid).” CDC. N.p., n.d. Web. 11 July 2014. <http://www.bt.cdc.gov/agent/hydrofluoricacid/basics/facts.asp>.
4. “Sulfuric acid .” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 18 Nov. 2010. Web. 12 July 2014. <http://www.cdc.gov/niosh/npg/npgd0577.html>.

Catalytic reforming is a conversion process present in petroleum refinery and petrochemical industries. In this reforming process, low octane naphtha is converted into a higher octane reformate products for gasoline blending and aromatic rich reformate for aromatic production.¹ To accomplish this reformation, the hydrogen molecules are re-arranged and re-structured in a naphtha feedstock, while breaking some of the molecules down into smaller ones.¹ The Naphtha feeds to the catalytic reforming are heavy straight run naphtha.¹ it transforms low octane naphtha into high-octane motor gasoline blending stock, and aromatics rich in benzene, toluene, and xylene with hydrogen and liquefied petroleum gas as a byproduct. ¹ Due to the valuable nature and demand of these products, the catalytic reforming process is one of the most important processes in petroleum and the petrochemical industry.

In United States refineries we had limits on catalytic reforming capacity. For any given refineries can and do change operations of their refineries to respond to the continual changes in crude oil and product markets, but only within physical limits defined by the performance characteristics of their refineries and the prosperities of the crude oil they process.² Currently in the US, the refinery Catalytic Reforming Capacity as of January 1^st is 2,541,250 (Barrels per stream Day).³ This production is limited due current environmental regulations set by the government for the amount of aromatics gasoline can contain.³ This is because when reformed the benzene content becomes carcinogenic, which lead to the environmental regulations limiting its use and what further processing is needed. The economics of the process all plays a key role in the capacity produced.³ Where as this process may result in a desirable product that the public wants, and producing more would lower the price in the market, the environmental impact is the limiting factor. A cheaper made product could have adverse effects on the environmental, so there needs to be limits on production and quality. This result in less production and higher costs of production and sale; however it’s a more sustainable option as a result of the added costs.

1. Lapinski, M.L., Baird L., James, “Handbook Petroleum refining”, Ed. Meyers, R.A., The McGraw Hill Companies , R. 4.32004.

2.  ICCT- AN INTRODUCTION TO PETROLEUM REFINING AND THE PRODUCTION OF ULTRA LOW SULFUR GASOLINE AND DIESEL FUEL, October 24, 2011

3. http://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=8_NA_8CRL_NUS_5&f=A

Catalytic cracking has been widely used since the early 1900’s for production of a range of fuels, predominantly light distillates, gasoline. Three types of Catalytic cracking exist, Houdry Catalytic Cracking, Thermafor Catalytic Cracking, and Fluid Catalytic Cracking. Fluid Catalytic Cracking has been widely adopted because of its thermal efficiency compared to the other two processes as well as its little to no down time during running. Catalytic cracking generally uses gas oil as a feed for the cracking processes. The gas oil is run through a column where steam is introduced and uses catalysts such as a zeolite or aluminum/silica catalysts for the separation process. The catalysts tend to build coke an inherently become deactivated requiring activation by heated air and/or steam. The products that come from these processes are Gas, Gasoline, Light Cycle Oil, and Heavy Cycle Oil. For the Fluid Catalytic Cracker, a product is also Decant Oil which can be used for fuel oil or for feedstock to produce needle coke or carbon black. Light Cycle Oil can be processed to produce diesel fuel. The Fluid Catalytic Cracker is used not only for its efficiencies but also because of its use of better catalysts and reactivation of the catalysts. These processes have a downfall in handling a wide range of feedstocks, primarily the heavier factions.

Hydrocracking has begun to be used in the late 50’s because of this growing demand for middle and light distillates as well as its flexibility to handle wide range of feedstocks. The hydrocracking plants have the ability to crack aromatics to produce paraffinic compounds without losing carbon, which increases the yields of the desired distillates without producing low-grade byproducts, such as coking. This is a major issue that wasted time and energy in the catalytic cracking plants. The catalyst used were typically metals such as nickel and copper as well as silica/alumina as in catalytic cracking. Since the process is bi-functional it also required highly active noble metals such as platinum and palladium. This process sheds the unwanted heteroatoms and increasing the H/C ratio. Hydrocracking can be used to treat the products that were resistive to cracking from the Fluid Catalytic Cracking plant such as Light Cycle Oil.

Hydrocracking costs more to perform which leads to the reasoning of performing both the Fluidized Catalytic Cracking for what it can do and using the Hydrocracking for what the FCC cannot do to supply the necessary amounts of fuels in demand. Although Hydrocracking is more flexible with feed, produces less coke, and gives use to the byproduct produced hydrogen, Fluidized Catalytic Cracking still serves its purpose for a cost effective way to produce light distillates such as gasoline, as well as coke that can be used for heating in plants and other purposes.