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 process was developed back in the 1920’s by Eugene Houdry to upgrade and put to better use residue using a process based on cyclic fixed bed configuration, which was later commercialized in the 1930’s.¹ Since then the process has been altered and upgraded into its current form as a fluidized bed catalytic cracking (FCC) process.¹ The feedstock for this process is often light gas oil obtained from a vacuum distillation column.¹ The process takes the feedstock and cracks ow value high molecular weight hydrocarbons to more valuable products of low molecular weight. This includes products such as gasoline, LPG Diesel, petrochemical feedstock’s such as propylene, and C4 gases like isobutylene, Isobutene, and butane.¹ The major reactions is the process are cracking, Isomerization, Dethrogeneration, Hydrogen transfer, Cyclization, Condensation, Alkylation, and Dealkylation.¹

Today Fluid Catalytic Cracking provides 50% of all transportation fuel, and 35% pf total gasoline fuel. In the process there are several specific steps that take place. The first step is the reaction step, in which the feedstock reacts with catalyst and cracks into different hydrocarbons.¹ Secondly the regeneration steps takes place, in which the catalyst is reactivated by burning off cook, and recirculated to reactor.¹ The fractionation step is next, in which the cracked hydrocarbon stream is separated into its various products. ¹

As technology progressed and as feed stocks became heavier with large concentrations sulfur, nitrogen, and heavy metals, a new process was in demand to obtain desirable products. Hydrocracking meet that need by providing a more versatile process which could convert low quality feed stock into high quality products like gasoline, naphtha, kerosene, diesel, and hydro wax used as petrochemical feedstock. ¹ This process uses a wide variety of feedstock’s like naphtha, atmospheric gas oil, vacuum gas oils, coke oils, catalytically cracked light and heavy cycle oil, cracked residue, and deasphalted oil.¹ The end products from this feed are high quality products will excellent product quality, and low sulfur content.¹ The feed in this process goes from straight run gas oil, vacuum gas oils, cycle oils, coker gas oils, thermally cracked stocks, solvent deasphalted residual oil, straight run naphtha, cracked naphtha, into desirable products including liquefied petroleum gas, motor gasoline, reformer feeds, aviation turbine fuel, diesel fuels, heating oils, solvent and thinners, lube oil, and FCC feed.¹

When we compare catalytic cracking to hydrocracking we see two very different processes.¹ Catalytic cracking is defined as a carbon rejection process, where Hydro-cracking is hydrogen addition process. Catalytic also uses riser-regeneration-configuration, where hydro uses down flow packed bed.¹ The products for catalytic are LPG’s and gasoline, and for hydro they are kerosene and diesel.¹ Catalytic cracking produces products which are rich in unsaturated components, where hydro cracking results in products with few aromatics, low sulfur and nitrogen content.¹

References

1. Lecture 5: Catalytic Cracking: Fluid Catalytic Cracking and Hydro-cracking
   1. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&ved=0CF0QFjAH&url=http%3A%2F%2Fnptel.ac.in%2Fcourses%2F103107082%2Fmodule6%2Flecture5%2Flecture5.pdf&ei=AZ25U6TABIqhyASrlICAAg&usg=AFQjCNG_5vWWo1ZoBVsPb_ZcB7lBXi3i3A&sig2=XKP7yFZafdnQw2BTKUpb5A&bvm=bv.70138588,d.b2U

Thermal cracking is a process by which heavy residues under severe thermal conditions are cracks.¹ This process allows for the formation of heavy fractions such as coke, once properly treated and finished.¹ The first refinery opened in 1861, however the first thermal cracking process was not developed until years later in 1913.² The first thermal cracker took heavy fuels and subjected them to both pressure and high heat, physically breaking the molecules into smaller ones, producing additional gasoline and distillate products.² With this additional process added, the yield of products per gallon of gasoline was increased, making petroleum refining more profitable. In the 1930s this process was even further improved to produce more desirable, valuable products.² Until the 1936 thermal cracking remained the method of choice.³ As technology developed, thermal cracking started to phase out because Catalytic cracking became more popular, as the costs for the process were being reduced. Catalytic cracking utilizes carbocation chemistry, utilizing a carbonium ion intermediate.³ Thermal cracking which was advance at its time, then became less utilized since the process produced random cuts in the hydrocarbon chains, yielding random length carbon chains.³ Catalytic cracking was the solution for this problem, whose produced in an organized manner, cutting chains near the middle.³ Thermal cracking remains an important process in petroleum refining today, however improved combined processes of thermal cracking have been developed for various purposes to improve yield and quality of products.³

1. Mohamed A. Fahim, Taher A. Alsahhaf and Amal Elkilani, Fundamentals of Petroleum Refining
2. http://www.ilo.org/oshenc/part-xii/oil-and-natural-gas/item/384-petroleum-refining-process
3. Jennifer Clemons , Brian Senger, Nicholas Filippelli, Fluidized Catalytic Cracking

In a distillation process such as vacuum distillation what forms at room temperatures is a unit contained of quantities of wax. The removal of this wax is necessary for the base stock to have desired low temperature properties. ¹ Two processes to separate the wax from the waxy petroleum fraction is solvent dewaxing and catalytic dewaxing processes. These processes help to prevent corrosion, protect catalyst in subsequent processes and to improve finished products by removing unsaturated, aromatic hydrocarbons from lubricant and grease stocks.² In solvent dewaxing a solvent such as toluene or methyl ethyl ketone are used.² These agents dissolves little wax at low temperatures and acts as a wax predicating agent. When the solvents are mixed with the product stream, the waxy oil and solvent are chilled.² A filter is then used which removes the predicated oil.² This process is much different however to the additional dewaxing method of catalytic dewaxing. This process is completed by selectively hydrodewaxing paraffinic wax contained in liquid petroleum.³ This process starts with a first serial catalyst bed under adiabatic cracking temperatures conditions, while controlling exothermal heat of reation.³ This then produced lighter olefin components, recovering partially hydrodewaxed liquid petroleum from a bottom portion of the first serial catalyst bed.³ The partially hydrocracked liquid petroleum is then further reacted to effect endothermic hydrodewaxing concurrently with exothermic hydrogen transfer causing dewaxing, hydrogenation and cyclization in the presence of hydrogen under adiabatic temperature conditions.³ This finishing process then allows for uniform hydro-dewaxing conditions and the obtaining of a high quality petroleum lubricant product.³ These two processes use very different techniques to finish the product, however complete the same goal of dewaxing the product steam, allows for a more desirable product which can operate under colder temperatures, increasing it usability and range of operation. It also helps to improve a lubricant oil low pour point by decreasing the temperature at which wax forms in the products and by improving its oxidation stability.³

1. http://www.bechtel.com/3868
2. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0CFgQFjAF&url=http%3A%2F%2Fkvbchemicalengg.com%2Fpdf%2FSOLVENT%2520EXTRACTION%2520AND%2520DEWAXING.pdf&ei=SrSlU6e8FISeyATKpoCYCg&usg=AFQjCNHfYhHhEZBls3BktgCc3MynD88vmQ&sig2=d9yAHalTi0rRCLfM9fhFvw&bvm=bv.69411363,d.b2k
3. http://www.google.com/patents/US5246568

Solvent Fractionation is a method of separating petroleum its separate groups of defined liquid, to reach a product of interest, parameters, and need. In a distillation process the incoming feed stock is separated it into different components with respect to defined parameters such as boiling point. ¹ When solvent fractionation is used through deasphalting, the feed is separated into different fractions based on the solubility behavior of the material.¹ This process is often used to separate out vacuum distillation residue or VDR which are present in the feed. This allows for the recovery of asphalt and deasphalted oil from the feed, which then can be catalytically cracked and treated to obtain valuable petroleum products.² This process allows for an improved petroleum treating process, better method for recovery of lubricating oil stocks from petroleum residua, provides a method for the recovery of lubricating oil stocks from a petroleum residuum, and provide a method for improved yield of lubricating oil.² The process behind this technique is solvent extraction. The first step of this process is to have the VDR fed to the deasphalter. The feedstock is then contacted with a solvent in a countercurrent extractor at temperatures and pressures to precipice the asphalt and resin fractions that are not soluble in the solvent.³ This then lead to the final product, with a separated out feed of asphalt. In this process an important concept is the solvent power. This is the ability of the solvent to dissolve asphaltenes.⁴ With non-polar solvents the solvent power can be expressed by the parameter δ which is defined as the ratio between the surface tension and the cubic root of the molar volume.⁴ This parameter allows for the explanation of certain apparent anomalies, such as the insolubility of asphaltenes and complete solubility. ⁵ It also produces an agreement with the derivation of the solubility parameter, for any one series of solvents the relationship between the amount of precipices and the solubility parameter.⁵

1. Course web page
2. http://www.google.com/patents/US3074882
3. http://www.intertek.com/testing/pilot-plants/deasphalting/
4. The Chemistry and Technology of Petroleum  By James G. Speight
5. Petroleum Refining Processes edited by James G. Speight, Baki Ozum

Vacuum Distillation is an important part of Petroleum processing in the United States. According to the EIA, approximately 80% of the refiners operating in the US have a Vacuum distillation unit (VDU).¹ This is a secondary processing unit added to petroleum refineries, consisting of vacuum distillation columns.² This process helps to produce petroleum from that of heavier oils that are left over from traditional atmospheric distillation.¹ In the refining process, the atmospheric distillation unit (ADU) separates the lighter hydrocarbons from heavier oils based on boiling process. The ADU can reach boiling point of crude oil up to 750 F, above which oil would usually thermally crack, or break apart, which hinders the distillation process.² The bottoms left over from the ADU then can be run through a vacuum distillation column to further refine and improve yield.¹ The products from vacuum distillation are slightly heavier than middle distillates, but can be further refined to make products such as gasoline and naptha.¹

To determine the temperature at which vacuum distillation can be used tp further process the petroleum, the Watson Characterization factor can be utilized. The plot of the Watson characterization is information showing the range of temperatures which can be used to avoid cracking, which would slow the refinery process. The Watson Characterization factor defines the upper bound temperature limit for vacuum distillation as a means to avoid cooking of the feed stock. Below the indicated bound, cooking risk would be minimal and above it, cooking could be a potential risk.

1. Vacuum distillation is a key part of the petroleum refining process http://www.eia.gov/todayinenergy/detail.cfm?id=9130

Crude oil is a raw material which is composed of different chemical with varying chain lengths of hydrogen and carbon atoms. To separate the hydrocarbons into their different fractions, distillation techniques can be used. There are commonly three different distillation methods used in petroleum refining. The first of these methods is True Boiling Distillation (TBP). With petroleum processing the boiling rang of the crude gives an indication of the quantities of the various products present.¹ TBP provides a reliable tool for characterizing of crude oil and petroleum in terms of their boiling point distribution.¹ It completes this by separating the individual components of the crude into individual mixtures components in order of boiling point.¹ Refiners use this information to model the crude distillation column.¹ However TBP is costly and takes significant time to analysis so it’s not always the best method or most practical for daily monitoring of crude distillation unit operation.¹

The second method of distillation is ASTM Distillation. In this process atmospheric distillation of petroleum products is performed using batch distillation unit to determine quantitatively the boiling range characteristics of the products.² By performing a simple batch distillation the boiling range can be found.² The information generated then can be used to find composition, properties, and the behavior of the fuel during storage and use. It also creates limits of use of petroleum products in commercial contract agreements, process refinery, control application, and for compliance to regulatory rules.

The last form of distillation is Equilibrium Flash Vaporization (EFV). This process Involved heating a flowing feed and separating of liquid and vapor in a flash drum.³ This process generates information about the vapor-liquid equilibrium, which can then be used for the design of equipment to separate the different components of a crude hydrocarbon mixture.⁴ This type of data is often reported as an isobaric curves on a plot showing vaporization vs. temperature.

References

1. BOILING POINT DISTRIBUTION OF CRUDE OILS BASED ON TBP AND ASTM D-86 DISTILLATION DATA Petroleum & Coal ISSN 1337-7027 Petroleum & Coal 53 (4) 275-290, 2011 Angel Nedelchev, Dicho Stratiev, Atanas Ivanov, Georgy Stoilov Lukoil Neftochim Bourgas

2. Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure

3. 3.FSC 432: Petroleum Processing- Equilibrium Flash Vaportization- Course Webpage

4. D. F. Othmer, E. H. Ten Eyck, S. Tolin Equilbrium Flash Vaporization of Petroleum Crude Oils or Fractions- Method and Apparatus for Determination-

Kyle Tress, krt5109@psu.edu , Tuesday May 20, 2014

The most recent data on the Supply of petroleum products in the United States is from the U.S. Energy Information Administration (eia) from February 2014. When looking at just the field production, the total supplied Crude Oil and Petroleum Products totaled on average 10,717 (Thousand Barrels per day).¹ In the prior months it was at 10,644 in January 2014, and 10,517 in December 2013.¹ In general there has been a trend of increasing supply of petroleum products in recent years, with the last decrease from 10,462 in September 2013, to 10,392 in October of 2013.¹ When looking at the annual data from as far back as 1970’s, the peak recorded supply was around 1973 with 10,975, then in general decreased till around 2006 with 6,860.¹ From that point on there has been an increasing amount supplied to the market with the current data recorded in 2013 with an average of 10,003.¹

When looking at February alone in the U.S. there was an additional 1,109 (Thousand Barrels per day) inputs from Renewable Fuels and Oxygenate Plant Net Production, 18,652 from Refinery and Blender net Production, 9,151 from imports, and 651 from Adjustments, all of which except for imports are up from the prior recorded data in January of 2014.¹ In recent years there has been a decreasing number of inputs from the peak in 2006 at 13,707, to 9,764 (Thousand Barrels per day), based on an average of the annual data.¹

When looking at the disposition of these supplies 14 (Thousand Barrels per day) was Stock Change, 17,572 Refinery and Blender Net Inputs, 3,611 Exports, 18,994 Products Supplied, as recorded from the eia data in February 2014.¹ The number of products supplied is up from 18,921 in January 2014, but down from 19,081 back in December of 2013.¹ The numbers of exports are as well down from 4,021 in January 2014, and down from 4,444 in December of 2013.¹ The trend in recent years have however been an increasing number of exports based on an average of the annual data from a low of 971 in 2001, to the current high of 3,594 in 2013.¹

Examining the types of products supplied to the market in February of 2014, 3,461 (Thousand Barrels per day) was from Natural Gas Plant Liquids and Liquefied Refinery Gases such as Ethane and Propane.¹ An additional 1,927 went to other liquids such as Ethanol and Unfinished oils.¹ There were finally 18,716 to finished petroleum products such as kerosene, finished motor Gasoline, or residual fuel oil.¹ The largest portion of Finished Petroleum Products came mostly from Refinery and Blender Net Production with 18,135 as recorded in February of 2014.¹ This is up from the 18,082 in January of 2014, but down from the 19,193 supplied in December of 2013.¹ When examining the average based on annual data there has been a general upward trend of increasing Finisher Petroleum products Supplied from U.S. Refinery and Blender Production. There was however a decrease in 2012 with 17,934 from the 18,054 in 2011, but quickly increased again to the current high of 18,417 in 2010.¹

With petroleum fuels in internal combustion engines a concern that must be addressed in the environmental impact that will occur, due to the source of anthropogenic pollution. This can include such emissions as NO_x, PM₁₀, PM_2.5, VOCs, SO_x, and CO.² This can be done by making thefuel cleaner as the refinery level. The first method is to reduce the sulfur content. Sulfur can inhibit the effectiveness of catalytic converters, so reducing the sulfur content make the fuel work more effectively and reducing tailpipe emissions.³ The second method is to reduce the benzene content. Benzene is a cancer causing risk to humans, so reducing the content reduces the cancer risks.³ A third method is to reduce the levels of aromatics hydrocarbons and the level of olefins, which react readily with other pollutants to form smog. Another method is to reduce the vapor pressure, which ensures that the fuel evaporates more readily. The final methods are to use an oxygen-containing additive which helps the fuel combust completely and burn cleaner.³

References

1. Supply and Disposition of Petroleum and Other Liquids, Energy Information Administration, From:http://www.eia.gov/dnav/pet/pet_sum_snd_d_nus_mbblpd_m_cur.htm

2. An Assessment of the Environmental Implications of Oil and Gas Production: A Regional Case Study, September 2008, Sector Strategies.

3. Cleaner-Burning Gasoline: An Update, September 25, 2008, California Environmental Protection Agency, From:http://www.arb.ca.gov/fuels/gasoline/cbgupdat.htm