World War II and Petroleum

Since the beginning of civilization there have been wars. Even though wars are mostly associated with negative ideals, more often than not war gives rise to the creation of new inventions and pushes the creative mind into overdrive. World War II’s effects on the petroleum refinery process were no exception. The military needed better lubricators for their war machines and accessible sources of combustible energy such as gasoline and diesel fuel increased greatly in demand for weapons such as tanks. The world Second World War had the effect of many different countries collaborating in order to fight against their oppositions. This included the collaboration of many different international refinement companies to ultimately find more effective ways to increase the octane number and overall yield of fuels such as diesel and gasoline. They improved upon ionic and catalytic cracking processes and concentrated all their efforts on supplying readily available fuel for deploying soldiers on war fronts as well as energy to fuel their vehicles as mentioned above. War has always had a major impact on the technology sector because at its core nature, war is a last ditch effort to get the upper hand on an opponent. I believe that there will still be many, many large-scale wars to come, along with the technological advancement they bring, before humanity as a whole is united under a singular government.

Wastewater Treatment

Most municipal wastewater refineries are used for the treatment of water from residential houses and areas. The equipment in these plants are not equipped to treat the toxic runoff from hydrocarbons that come from petroleum refineries. These wastewaters are divided into four different types of categories which are: sanitary sewer, storm water, water and steam, and cooling water. These categories contain many harmful pollutants such as dissolved solids, suspended solids, cyanides, and liquid hydrocarbons among a few others. Utilizing a steam process these pollutants must be taken out from the water from the water. After the completion of this process where the toxic chemicals are stripped from the wastewater, they can be brought to municipal wastewater treatment plants and the water can be treated. There is also the option of using biological means to treat the water. The use of microorganisms that eat or dissolve the pollutants can be used as a secondary means of treatment. This process produces bicoke which. Wastewater treatment is a very important part of keeping any urbanized area’s water clean and safe.

Catalytic Reforming

The discovery of the catalytic reforming method was to increase the yield of high octane number gasoline yields form refineries. Because of the large demand of gasoline form automobiles, many refineries today still utilize the method of catalytic reforming to increase the amount of higher quality gasoline from their crude oil feedstock.  Some of the by-products worth mentioning from this process are hydrogen and LPG because of their increasing use in the refining industry. The hydrogen is used for hydrocracking and hydrotreating and LPG has been used increasingly for fuel for vehicles.

The process of catalytic reforming involves taking heavy naphtha straight run fractions that typically have a low-octane number and converting them into high-octane number products. As stated in the lesson, many catalytic reforming processes utilize platinum which means that in many cases the naphtha feedstock needs to be hydrotreated in order to protect the sulfur or nitrogen species from platinum poisoning. Interestingly enough, the most desired product of catalytic reforming is not high octane gasoline, but rather hydrogen. Hydrogen is used in many applications in the refining industry but is most desired in hydrocracking, a cracking process covered in previous lessons.

One limitation of catalytic reforming is the side reaction of hydrocracking. Mainly because this process consumes hydrogen (a greatly desired by product of catalytic reforming) and produces gaseous hydrocarbons which decrease the reformate yield. Although these reactions are exothermic they can still occur when there is a high concentration of hydrogen gas as well as being in a high temperature environment.

Catalytic reforming is a very important part of the refining industry and has become an even more important part when coupled with hydrocracking as the by-products can be very beneficial between processes. The united states and many other countries around the world utilizes the chemical reactions of catalytic reforming to produce higher yield gasoline which can be used for fuels in automobiles s well as the formation of LPG and hydrogen gas.

Catalytic and Hydrocracking

Cracking is the process of breaking straight chain alkanes into smaller straight chains hence the term “cracking.” This process was, and still is, and extremely important process in developing higher quality products such as gasoline that had an ever increasing octane number, something that is very desirable when producing gasoline. The two types of cracking processes are catalytic and thermal. In addition Catalytic cracking can be broken into catalytic cracking and catalytic hydrocracking.

Catalytic hydrocracking uses the same principles of catalytic cracking will also relying heavily on the elevated partial pressure of hydrogen gas. One positive attribute of catalytic hydrocracking is its ability to accept many different feeds that with minor adjustments can have a large effect on desired the product yields. FCC produces high octane gasoline from straight run gas oil. The long chains of n-alkanes in the feedstock are broken up through the process of catalytic cracking into smaller straight chain i-alkanes, or isoalkanes. Other products are cycloalkanes and other aromatic structures. As noted in the lesson, LPG, cycle oils, and olephin-rich light hydrocarbons are very important products of this cracking method as well.

The whole purpose with hydrocracking is the addition of hydrogen to keep the levels of coke productions under control. Without this, it would be much more difficult to introduce heavier crude oil fractions as a feedstock due to the high amounts of coking on the catalysts. So this is why hydrocracking was invented.

Catalytic cracking involves the presence of acid catalysts. This process has the effect of causing asymmetric breakage of bonds. Because of the use of free radicals in many cracking reactions, namely beta bond scission and hydrogen abstraction, the reactions are self-propagating as both free radicals and carbocations are formed. The formation of these two very highly unstable atomic and molecular structures respectively, result in the reaction proceeding until recombination is achieved.

Catalytic and catalytic hydrocracking are two very important processes that dominate the refining industry in their complexity and their yields of production of highly desirable products. These methods are constantly being heavily researched in order to better the products and the methods used in order to obtain them.

Thermal Cracking

The process of thermal cracking has been around for quite some time. Being discovered back in the late 1800’s, it is a very effective way of breaking down longer straight chain paraffin into shorter chian ones through the use of high temperatures and free radical reactions. The most commonly used cracking methods utilizing free radical reactions are hydrogen abstraction and beta bond scission. Hydrogen abstraction is when a free radical “plucks” away hydrogen from the carbon chain causing it to become shorter. Beta bond scission is when the beta bond, in respect to the position of the free radical, becomes “cut” due to the movement of the free radical along the carbon-carbon chain. After doing some quick research it is apparent that the process of more conventional thermal cracking as we recognize it was invented back in 1912 and operated under temperatures between 700-750F and a constant pressure of 90psi. However more modern techniques of thermal cracking involve what we know as vis breaking and coking. Coking has three main types which are flexi, fluid, and delayed coking. Each has a distinctive process that separates itself from the other two. For example delayed coking always utilizes two drums. Vis breaking occurs when the viscosity of the crude oil is reduced while using high temperatures to accomplish this. Overall the thermal cracking process has become an invaluable part of the petroleum, refining industry and is a growing field that is constantly making minor advancements to get the best result out of its feedstock.

Source Wikipedia: http://en.wikipedia.org/wiki/Cracking_(chemistry)

 

 

 

Dewaxing: Chemical and Physical

Desirable by-products are ones that come from lube oil base stocks such as waxes that consist of long chain paraffins. There are two ways of “dewaxing” which removes wax from the feedstocks. These methods are solvent dewaxing and catalytic dewaxing.  They are physical and chemical methods respectively. Solvent dewaxing separates waxes using freezing points. Freezing is done in stages after being mixed with the solvent.  This process then forms wax crystals which is then further modified to produce slack wax. Slack wax is found in many everyday common objects such as candles. This method is done in a deasphalting process separates vacuum distillation residue. After placing the residue into an aromatic solvent, an alkane solvent is added which has the effect of some of the compounds to become insoluble. When this happens they precipitate out.

Catalytic dewaxing ultimately increases the ratio of i-paraffins to n-praffins. It does this through the chemical reactions of long chain n-alkanes which will lower the pour point of the wax. When comparing catalytic dewaxing to solvent dewaxing, catalytic waxing is the better method. It gets more lube oil stock because of the variance in pour point as well as its ability to produce both lube oil base stock and light distillates.