* CRUDE OIL
Crude oil is a naturally occurring, unrefined product composed of hydrocarbon deposits and other organic materials. A type of fossil fuel, crude oil can be refined to produce usable products such as gasoline, diesel and various forms of petrochemicals.
Crude oil varies greatly in appearance depending on its composition. It is usually black or dark brown (although it may be yellowish, reddish, or even greenish).
Various types of Crude Oil supplied include
– Azeri Light
– ESPO Blend
– Siberian Light
– Saudi Light
– Oman Blend
– Bonny Light
* DIESEL D2
In the refining process, Crude oil is converted into transportation fuels — gasoline, jet fuel, and diesel fuel; and other petroleum products, such as liquefied petroleum gas (LPG), heating fuel, lubricating oil, wax, and asphalt. High-gravity crude oils contain more of the lighter products needed for the production of transportation fuels, and generally have lower sulfur content. Modern refining processes can also convert low-gravity crude oils into lighter products, at an added expense of more complex processing equipment, more processing steps, and more energy.
Diesel or diesel fuel is a specific fractional distillate that is used as fuel in diesel engines.
Diesel is produced from crude oil, and is sometimes called petro-diesel when there is a need to distinguish it from diesel obtained from other sources such as biodiesel. It is a hydrocarbon mixture, obtained in the fractional distillation of crude oil between 200 °C and 350 °C at atmospheric pressure.
Various types of Diesel Fuels available:
– Ultra Low Sulphur Diesel: Includes Euro-5 and Euro-6 Diesel fuels, which have a sulphur content lower than 50ppm
– Low Sulphur Diesel, such as D2
– High Sulphur Diesel
Mazut is a residual fuel oil often derived from Russian Crude Oil sources and is either blended with lighter petroleum fractions or burned directly in specialized boilers and furnaces. It is also used as a petrochemical feedstock.
Bunker Fuels which are also referred to as Marine fuels come in various classifications. The more popular are: – IFO 380 – Intermediate fuel oil with a maximum viscosity of 380 centistokes (<3.5% sulphur)
– IFO 180 – Intermediate fuel oil with a maximum viscosity of 180 centistokes (<3.5% sulphur)
– LS 380 – Low-sulphur (<1.0%) intermediate fuel oil with a maximum viscosity of 380 centistokes
– LS 180 – Low-sulphur (<1.0%) intermediate fuel oil with a maximum viscosity of 180 centistokes
– MDO – Marine diesel: roughly equivalent to No. 2 fuel oil, made from distillate only oil
– MGO – Marine gasoil: this is a blend of heavy gasoil that contains very small amounts of black refinery feedstocks, but has a low viscosity up to 12 cSt so it need not be heated for use in internal combustion engines
– LSMGO – Low-sulphur (<0.1%) Marine Gas Oil - This is the fuel used in EU Ports and Anchorages. In accordance to EU Sulphur directive 2005/33/EC
– ULSMGO – Ultra-Low-Sulphur Marine Gas Oil – referred to as Ultra-Low-Sulfur Diesel (sulphur 0.0015% max) in the US and Auto Gas Oil (sulphur 0.001% max) in the EU. Maximum sulphur allowed in US territories and territorial waters (inland, marine and automotive) and in the EU for inland use.
* LIQUEFIED PETROLEUM GAS (LPG)
Liquefied petroleum gas (also called LPG, LP Gas, or autogas) is a mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles, and increasingly replacing chlorofluorocarbons as an aerosol propellant and a refrigerant to reduce damage to the ozone layer.
LPG mixes may be primarily propane, primarily butane, or the more common mixes including both propane and butane, depending on the season. In winter more propane, in summer more butane. Propylene and butylenes are usually also present in small concentration. A powerful odorant, ethanethiol, is added so that leaks can be detected easily. The international standard is EN 589.
LPG is synthesised by refining petroleum or ‘wet’ natural gas, and is usually derived from fossil fuel sources, being manufactured during the refining of crude oil, or extracted from oil or gas streams as they emerge from the ground. LPG is considered a “clean fuel” as it burns cleanly with no soot and very few sulfur emissions, posing no ground or water pollution hazards. LPG has a typical specific calorific value of 46.1 MJ/kg compared to 42.5 MJ/kg for diesel and 43.5 MJ/kg for premium grade petrol (gasoline). However, its energy density per unit volume is lower than either petrol or diesel.
At normal temperatures and pressures, LPG will evaporate. Because of this, LPG is supplied in pressurised steel bottles. In order to allow for thermal expansion of the contained liquid, these bottles are not filled completely; typically, they are filled to between 80% and 85% of their capacity. The ratio between the volumes of the vaporised gas and the liquefied gas varies depending on composition, pressure and temperature, but is typically around 250:1. The pressure at which LPG becomes liquid, called its vapour pressure, likewise varies depending on composition and temperature.
* AVIATION KEROSENE / JET FUEL
Jet fuel is a hydrocarbon-based aviation fuel for aircraft planes with turbojet engine.
Jet fuels are produced for subsonic aircrafts in accordance with GOST 10227-86 and supersonic aircrafts in accordance with GOST 12308-89. There are five grades of fuel for subsonic aircrafts (ТС-1, Т-1, Т-1С, Т-2 and РТ) and two grades of fuel for supersonic aircrafts (Т-6 and Т-8В). ТС-1 fuels (superior and premium grade) and РТ fuel (superior grade) are currently massively produced.
TC-1 fuel is a product of straight run distillation of sour crude (desired cut — 150—350 °C). If sulfur and RSH contents are significantly high, it is hydrotreated or demercaptanised and used in the mixture with straight run cut. The content of hydrotreated component is limited to 70% concentration to prevent minimization of wear-reducing properties of the fuel. The most popular type of jet fuel is for subsonic aircrafts. It is used both in military and civil aviation. It is also used for enrichment through flotation technique.
Product of distillation of low sulfur content naphthene based oil with boiling range of 130—280 °C. It contains a large volume of naphthenic acids and therefore has a high acidity level. It is leached and washed with water after fractionation. Heterotopic naphthenic compounds in the fuel provide good wear-reducing properties and chemical stability. On the other hand, fuel has very low thermal oxidative stability. Continuous tests have demonstrated that when this type of fuel is used in НК-8 (Tu-154 (А,Б,Б-1,Б-2) and Il-62) engines, this leads to increased resin deposits and reduced life term of the engine. Only premium fuel grades are currently produced with limited volumes.
Product of distillation oil of wide fractional composition — 60-280 °C. It contains up to 40 % gasoline cuts which leads to high pressure of saturated vapours, low viscosity and density. The maximized pressure of saturated vapours will lead to potential formation of vapour locks in the fuel system of the aircraft which limits its flight altitude. It is considered to be a back-up fuel with regard to ТС-1 and РТ.
It is produced by means of hydro-treatment of straight cut distillation of jet fuel with boiling range of 135—280 °C. As a result of hydro-treatment the content of sulfur and RSH gets minimized, but wear-reducing properties and chemical stability deteriorate. Wear-reducing and auto-oxidising additives are added into the fuel in order to prevent deterioration of properties. RT fuel fully corresponds to international norms and even exceeds certain indicators. It has good wear-reducing properties, high chemical and thermal oxidative stability, low sulfur content and almost no RSHs. The fuel can be stored up to 10 years and fully serves engine requirements.
It is produced by means of deep hydration of straight run cuts of 195—315°C, from naphthenic oils. It is used in supersonic aviation mainly in the Air Forces of the Russian Federation.
It represents a hydro-treated cut with boiling range of 165—280 °C. In the event of naphthenic low sulfur oils straight run cut is allowed to be used without hydro-treatment. It is used in supersonic aviation mainly in the Air Forces of the Russian Federation.
* BENZENE A-80, 92, 95
The present day motor and aviation gasoline should meet the different requirements ensuring economic and reliable engine operation, and operating requirements:
– to have good evaporating capacity which allows to get homogeneous air-fuel mixture of tailored composition at any temperatures;
– to have hydrocarbon-type content ensuring the stable non-detonating combustion process at all modes of engine operation;
– not to change its composition and properties on long storage and not to have unfavorable effect on fuel system components, reservoirs, rubber technical goods;
– to have good antiknock properties, etc.
Ecological properties of fuel are significantly highlighted in recent years.
Clean fuel burning process in engine requires to transfer it from liquid state to vaporized state in short term and mix it with air at a certain ratio 1:14, i.e. to create air-fuel mixture. Physico-chemical parameters that influence the evaporating capacity of gasoline, include saturated vapor pressure, fractional composition, latent heat of evaporation, vapor diffusion coefficient, viscosity, surface tension, thermal capacity, density. The most important of the above listed indicators determining the evaporating capacity of gasoline are saturated vapor pressure and fractional composition.
Saturated Vapor Pressure
Saturated vapor pressure depends on temperature and ratio of vapor and liquid states and decreases due to decrease of temperature and increase of the ratio of vapor and liquid states. Saturated vapor pressure is determined at 37.8°С and ratio of vapor and liquid states (3.8-4.2):1 in “Reid Vapour Pressure Bomb” (GOST 1756-52) or mechanical dispersion machine such as “Vihr” (GOST 28781-90) in a laboratory environment.
Fractional composition of gasoline shall be determined on the special device, recording initial boiling point, evaporating temperature of 10, 50, 90 % and end boiling point, or evaporating volume at 70, 100 and 180°С. Requirements for fractional composition and saturated vapor pressure of gasolines are determined by the structure of motor engine and environmental operating conditions.
This indicator characterizes the capacity of motor gasolines to prevent self ignition under compression. High anti-knock value of fuels ensures their normal combustion at all modes of engine operation. Fuel combustion process in engine is of radical character. Under compression of air-fuel mixture, the temperature and pressure are raised and oxidation of hydrocarbons which is intensified after mixture ignition, is occurred. Intensive accumulation of peroxide compounds occurs if hydrocarbons of unburned part of fuel has insufficient resistance to oxidation, after that explosive disintegration is occurred. Thermal explosion which leads to self-ignition of fuel is occurred in the high concentration of peroxide compounds.
Motor gasoline should be neutral and non-corrosive for metals and reservoirs, and its combustion products should be non-corrosive for engine parts. Corrosiveness of gasoline and its combustion products depend on content of total and mercaptan sulphur, acid capacity, content of water-soluble acids and alkali, presence of water. These indicators are described in technical standard documentation for gasoline. Gasoline should stand the copper strip test. The efficient method of corrosion protection is addition of special anti-corrosive or multi-purpose additives to gasoline.
* GREEN SPONGE PETCOKE
Green petroleum coke is generated by delayed coking during the conversion of crude oil into liquid fuels such as gasoline and jet fuels. Green coke quality is derived mainly from the quality of crude oil that a refinery consumes.
The quality of the coke determines its use. High sulfur coke is consumed as a solid fuel for its BTU content, competing with coal, while low sulfur, low impurity coke is upgraded through calcining for consumption as a critical raw material in the aluminum and steel industries.
LIGHT CYCLE OIL
Light Cycle oil is a lubricating oil – a liquid residue produced in the petroleum industry when catalytic cracking is employed to convert heavy hydrocarbon fractions remaining from earlier stages of crude oil refining into more valuable lighter products.
Catalytic cracking produces petrol (gasoline), liquid petroleum gas (LPG), unsaturated olefin compounds, cracked gas oils, cycle oil, light gases and a solid coke residue. Cycle oil may be processed further to break it down into more useful products; in particular it may be mixed with heavier products and put through the refining process again (recycled).