In the refinery process, as we already know, crude oil is fed into the fracturing tower and will yields petroleum by-products depending on the type or quality of the crude oil feeds – lighter feeds will yield industrial fuel oil, heating oil, diesel fuel, kerosene, jet fuel and gasoline. Although the latter three products require additional steps in the refinery process, these yields all come from the lighter crude oil feeds. Towards beneath the fracturing tower, where the heavier crude oil feeds settle, yields waxes for candles and shines, lubricating oils, greases, petroleum coke and asphalts.
Petroleum products after the refining process measured on average barrels of crude oil.
Successful petroleum retailing industry faces significant challenges; with low product differentiation, customer loyalty, intense competition, regulation and all. This requires operators to adopt new and innovative strategies to ensure sustainable and optimal business performance.
This book is designed for individuals that are in or are serving in the oil and gas downstream industry looking for a comprehensive understanding on the retail business. The book examines the entire industry value chain from the customer through the gasoline nozzle. across traditional oil company perspective to grocery stores and convenience food store chains. Readers will gain knowledge and understanding of the retail petroleum consumers and how retailers cater to their specific target customers, the various business operations, technology and methodologies used across the industry.
Let’s focus on Gasoline and Diesel (Fuels) and Lubricant Oils which include engine oils, greases and additives (Lubes) as these are close to our hearts being motorists or owner of sorts of vehicles which are generally found in every gasoline station we see in our daily lives. We basically travel every day, and reaching our destinations and home safely and efficiently depending on our vehicle and the products we use into our vehicles, basically the fuels and lubes, not withstanding on how we drive safely.
Vehicles have so many parts but the main part of every vehicle – motor cycles, cars, jeeps, trucks and buses is its engine essentially. In the car industry, the engine is normally called the heart of the vehicle. It is responsible in making the vehicle run from one point to another. Other parts of the vehicle functions basically as support and safety. However, the overall efficiency of the vehicle is based on the performance of its engine. Engines may vary from sizes and type of fuel and lubes used. But basically, engines providing the power for the vehicle to move from one point to another follow a four-stroke cycles: 1st) Fuel Intake, 2nd) Compression of the Fuel, 3rd) Power which forces the piston down, and 4th) Exhausting of burned fuels. The only difference is on the 3rd cycle, the fuel is powered via spark in gasoline engines and compressed to explode in diesel engines. Repeat this cycle enough times per minute, and it has the ability to make any gear-head grin. Whether diesel or gasoline powered, the four engine strokes are the same, but there are key differences as to how the strokes are executed. Graphical representations of the four-stroke engines cycle are best shown below:
For gasoline engines, the intake stroke generally involves pulling air and fuel into the combustion chamber. At this point, a diesel engine is only pulling in air. Second is compression, where both engine types squeeze down the air into a small pocket. Third is Ignition, it is controlled separately for each fuel type. Gasoline engines use a spark plug to time and start the power stroke. This small arc of electricity ignites the air fuel mixture and the powerful blast forces the piston down, churning out that highly craved horsepower. A diesel engine, on the other hand, only has a pocket full of hot air before the power stroke. As the piston approaches the top of its compression stroke, the air is hot enough from being squeezed down so small that when diesel fuel is injected, it immediately ignites. Thus, the timing of ignition for diesel engines is driven by the fuel injectors. And the fourthly, the last cycle, both engines function similarly for the exhaust stroke, where a valve opens up and the piston forces the spent fumes out of the cylinder.
Gasoline and diesel fuel are the two main sources of energy for today’s vehicles. Although they are both derived from the same source of petroleum they certainly aren’t interchangeable and have different chemical properties and are burned in two different ways. Vehicles that use gasoline have to use spark plugs in order to ignite the fuel, that’s why gasoline engines have a relatively low compression ratio. Because diesel engines have much higher compression ratios, a diesel engine doesn’t utilize spark plugs. As gases are compressed, their temperature will increase, and diesel engines have such a high compression ratio that the heat produced by the compression is enough to ignite the fuel/air mixture.
Of the two fuels, diesel tends to get better gas mileage than gasoline because it has a higher density, which leads more energy per each explosion within the cylinder. Also, diesel engines tend to be more efficient by nature. Despite the better fuel economy from diesel fuel, gasoline is the cleaner burning of the two, and is one of the main reasons why diesel cars aren’t as popular in the United States. In fact, diesel prices are more expensive in the United States because of environmental issues.
Milestone and breakthroughs in research now allows electric and hydrogen fueled cell vehicles the norm specially when we consider the environment as the issue. But until then, its sustainability and price in the market becomes a reality, we will have to contend driving vehicles that run on fossil fuels. Basically, the characteristic of gasoline is the octane rating and the ethanol content, and that of diesel is cetane rating and sulfur content.
A quick explanation of octane ratings would be that they refer to a fuel’s ability to resist knock or pinging. The higher the score, the greater the resistance to that phenomenon that can happen in an engine’s combustion chamber. Knocking occurs because of many reasons, but with gasoline, it is all about preventing the fuel from igniting because of the level of heat in a combustion chamber. Another specification of gasoline these days is the Ethanol content, which varies from one continent to another. In the United States, it even varies from one state to another, but laws dictate that most of the gasoline sold in the country should not exceed 10% of ethanol content. That happens because vehicles sold before 2001 cannot run with more than 10% ethanol.
If your vehicle runs on diesel, you have probably noticed that no octane figures are advertised. Instead, diesel fuel is rated with a “cetane number,” which ranges from 40 to 55 around the world. Just like with gasoline, the higher number, the better the fuel. In Europe, diesel fuel must have a minimum cetane number of 51, while North America mandates a minimum of 40. Diesel fuel usually receives additives like detergents, water dispersants, and other substances that are meant to improve lubricity. The detergents are not like those used in your washing machine, but are supposed to clean the fuel injectors as it is sprayed through them, while water dispersants are substances that prevent the accumulation of water.
Diesel fuel has another important specification besides its cetane number, and it is the quantity of sulfur. In the USA, all diesel fuel sold after December 1, 2010, must be “Ultra-Low Sulfur,” which holds a maximum of 15 ppm of Sulfur. Sulfur used to be a lubricant in diesel fuel when it was combined with nickel, but oil makers have managed to replace it with alternatives to help it perform as well as the previous standard, Low Sulfur Diesel fuel.
- Each type of gasoline fuel has it’s own formulation of ADDITIVES;
- ADDITIVES provide for the specific OCTANE rating of each type of fuel and price that the customer wants to buy at the service station;
- Additives provide for a cleaner and more efficient burn of gasoline inside the fuel intake system of gasoline fed vehicles;
- All gasoline fuels are unleaded in nature because it is environmental friendly.
- All gasoline fuels have a specific OCTANE rating to classify it from each other. There is a sticker on the pump to show the OCTANE rating of the type of gasoline fuel;
- Diesel fuel has no octane rating. It has a cetane rating. Check with your company on its cetane rating;
- Remember – Always ask the customer what type of fuel they require & confirm this and check what type of fuel and its octane(if gasoline) rating on the FLAP of the vehicle that covers the fuel cap.
Lubricants and Greases:
Lubricants (lubes) are the next thing you’ll probably look for in gasoline service stations. And likely, they are branded and shelved according to usage and prices. Lubes are liquid-filmed substances, usually organic and are applied to reduce friction between surfaces that come into contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces.
Greases are semisolid lubricants consisting of soap emulsifiers formulated with mineral or vegetable oils. The characteristic feature of greases is that they possess a high initial viscosity, which upon the application of shear, drops to give the effect of an oil-lubricated bearing of approximately the same viscosity as the base oil used in the grease. Greases are applied to mechanisms that can only be lubricated infrequently and where a lubricating oil would not stay in position. They also act as sealants to prevent ingress of water and incompressible materials. Grease-lubricated bearings have greater frictional characteristics due to their high viscosity.
As we all know by now, lubes and greases are petroleum by-products of crude oil in the refining process and fall under the heavier refined crude oil. The basic components of lubes are base oil and additives whereas greases are base oils, additives and thickeners. Lubes and grease are classified based on physical properties and performances to aid in the selection of the proper lubricant for an application and to provide some standard basis for comparison on usage. Their classifications provide a baseline to meet certain set of needs or objectives and most often these targets are established to keep pace with new engine or equipment designs.
The classifications are most often developed by the technical societies that represent the manufacturers of the equipment or the oil industry. Sometimes Original Engine Manufacturers (OEMs) establish their own classification systems especially when their needs are not well represented by the industry as a whole. The classification of lubes and greases depend and vary on the products’ purpose and scope of usages and their classifications evolve keeping pace with technology and the environment.
SAE (Society of Automotive Engineers) was established to classify engine oils used in automobiles and has also been extended to classify lubricants for transmissions and final drives. The classifications for engine oils are split into two sections. Those with a “W” are for low temperature applications. “W” = Winter. Those without the “W” are for all other warmer applications. The classifications are defined based on both viscosity and shear properties such as multi-grade lubes SAE 5W-40 formulated to meet both low temperature environments and higher temperatures through the use of additives like viscosity index Improvers.
The SAE Grades are set by measuring the maximum temperature at which the lubricant reaches a viscosity of 150,000 cP (centipoise). Viscosity limits are then established on the minimum side to be sure sufficient viscosity is available for effective lubrication. It is the responsibility of the gear manufacturer to specify the SAE Grades that will provide effective lubrication under differing ambient conditions.
Axle and Transmission SAE Grades are not linearly related to Engine Oil SAE Grades. For instance the viscosity range covered by SAE 40 & 50 Engine Oil is about the same as SAE 90 Gear Oil. The viscosity range covered by SAE 10W & 20W is about the same as SAE 75W Gear Oil. Multi-grade axle and transmission oils such as SAE 85W-140 are formulated to meet the broader viscosity range using additives like viscosity improvers.