CRUDE DISTILLATION UNIT:
Crude oil is sent to the atmospheric distillation unit after desalting and heating processes. The main purpose of atmospheric distillation is primarily separation of various ‘cuts’ of hydrocarbons namely; fuel gases, LPG, naphtha, kerosene, diesel and fuel oil. The heavy hydrocarbon residue left a the bottom of the atmospheric distillation unit is sent to vacuum distillation column for further separation of hydrocarbon under reduced pressure.
The pressure profile in the atmospheric distillation unit is close to atmospheric pressure with highest pressure at the bottom stage which gradually drops down till the top stage of the column. The temperature is highest at the bottom of the column which is constantly fed with
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The gradual variation of temperature and pressure from one stage to another and considerable residence time for vapors and liquid at the tray help to create near equilibrium conditions at each tray. So ideally we can have a number of different vapor-liquid equilibriums at different stages of this column with varying temperature and pressure conditions. This means that the hydrocarbon composition also varies for different trays with the variation in temperature and …show more content…
PROCESSES IN THE CRUDE DISTILLATION UNIT:
There is only one process that takes place in the crude distillation unit, which is distillation, as the name suggests.
DISTILLATION
Modern crude distillation towers can be of up to 50 meters tall and contain 20 to 40 fractional trays spaced at regular intervals. Before crude enters the distillation tower, desalted oil goes through a network of preheat exchangers to a fixed heater which brings the temperature up to 350 degrees Celsius. Caution is taken so that the crude oil does not exceed 350 degrees Celsius because it starts to crack and deposit carbon inside the pipes and equipment through which it flows.
The hot crude enters the distillation tower just above the bottom. Steam is added to enhance separation which is achieved by decreasing vapor pressure in the column. Most of the hot oil vaporizes as soon as it enters the tower. Unvaporized heavy oil and or asphalt residue drops to the bottom of the tower, where it is drawn off. The vapor then rises through the distillation trays, which contains perforations and bubble cups. Each tray permits vapors from below the bubble through the cooler, condensed liquid on top of the tray providing excellent vapor/liquid contact. Condensed liquid flows down through a pipe to the hotter tray below, where the higher temperatures cause re-evaporation. A given molecule evaporates and condenses many times before finally leaving the
Normally, emulsified water is generally present in crude oil as a result of the mixing occurring during production operations and referred to as oil field emulsion. This emulsion can be encountered at numerous stages include during drilling, producing, transporting and processing of crude oil. However, the formation of emulsion creates problems in oil field industry. They might increase the cost of production and also transportation; accumulate in the refinery tank age, pipeline corrosion, equipment failure, plugged pipeline. For economic and operational reasons, it is necessary to remove water completely from the crude oil emulsion before refining and transporting those. In order to separate the water content of the produced crude oils, the emulsions have to be broken through demulsification process.
The comparison between the vapour compression and vapour absorption systems are given in Table 1
After the oil/gas mixture is drawn from the ground, it is then stored into a storage tank and allowed to rest for a while. Then the gas is piped off to a set of distillation columns to clean up the ethane. In order to activate the chemical reaction necessary to separate the ethane, a thermal cracking unit (a sort of long heated tube) i.e. a plug flow reactor is used. After a series of distillations, ethylene exits the tube.
Norbert Rillieux invented the triple effect vacuum evaporator. The "triple effect" is for the multiple things that the system does all at the same time. The "vacuum" is for the vacuum of air that is used in the system, and the "evaporator" is for the sugarcane liquid syrup that is heated and evaporated into regular sugar. The actual system is somewhat complicated, so please see the picture that is provided.
The Olefins II Unit makes hydrocarbons from naphtha or natural gas using furnaces. After distillation, the p...
" Oil is the life blood of our modern industrial society. It fuels the machines and lubricates the wheels of the world’s production. But when that vital resource is out of control, it can destroy marine life and devastate the environment and economy of an entire region…. The plain facts are that the technology of oil-- its extraction, its transport, its refinery and use-- has outpaced laws to control that technology and prevent oil from polluting the environment…" (Max, 1969). Oil in its many forms has become one of the necessities of modern industrial life. Under control, and serving its intended purpose, oil is efficient, versatile, and productive. On the other hand, when oil becomes out of control, it can be one of the most devastating substances in the environment. When spilled in water, it spreads for miles around leaving a black memory behind (Stanley, 1969).
...into fresh water through a distillation process. The distillation plant on submarines can produce 10,000 to 40,000 gallons of water per day. The water is mainly used for cooling equipment and for the crews’ personal use.
For the generation of electricity, hot water, at temperatures ranging from about 700 degrees F, is brought from the underground reservoir to the surface through production wells, and is flashed to steam in special vessels by release of pressure. The steam is separated from the liquid and fed to a turbine engine, which turns a generator. In turn, the generator produces electricity. Spent geothermal fluid is injected back into peripheral parts of the reservoir to help maintain reservoir pressure. If the reservoir is to be used for direct-heat application, the geothermal water is usually fed to a heat exchanger before being injected back into the earth. Heated domestic water from the output side of the heat exchanger is used for home heating, greenhouse heating, vegetable drying and a wide variety of other uses.
From the graph 2, it is seen clearly that the relationship between purity and boil-up rate is inversely proportional to each other. In order to achieve a good separation and high purity between the liquid and the vapour must be brought to an intimate contact by counter-current flow. Increasing the vapour flow actually means decreasing the interaction time between the down flowing liquid and up flowing vapour inside the column. Hence, if ...
» Downstream: significant refineries incorporate unrefined petroleum preparing and transport of items to retail outlets.
The catalytic process occurs at lower temperature anf offers higher selectivity but requires frequent regeneration of the catalyst. Then, the products are cooled and introduced into a pair of separators which separate the unreacted hydrogen. The unreacted hydrogen is compressed and recycle back to the feed and reactor. The products that leaving the separators are heated before introduced into a distillation column which the toluene is separated from the stream and recycle back to the...
Process cd : This liquid refrigerant is collected in the liquid storage tank and later on it is expanded to low pressure and temperature by passing it through the throttle valve. At point d we have low temperature liquid refrigerant with small amounts of vapour .
... In an industrial production, the water and fat and forced through a narrow slit at high pressure, breaking the fat droplets and dispersing them. The size is usually less than one thousandth of a millimeter. The mixed is pumped into the tank room, which is at 36 degrees and is there for four to eight hours. Afterwards the mix is pumped to the flavor tank, where a tank holding 500 gallons of ice cream is transformed into ice cream with different flavors.
turbine via interceptor valves and control valves and after expanding enters the L.P. turbine stage via 2 numbers of cross over pipes. In the L.P. stage the steam expands in axially opposite direction to counteract the trust and enters the condenser placed directly below the L.P. turbine. The cooling water flowing throughout the condenser tubes condenses the steam and the condensate collected in the hot well of the condenser. The condensate collected is pumped by means of 3*50% duty condensate pumps through L.P. heaters to deaerator from where the boiler feed pump delivers the water to boiler through H.P. heaters thus forming a closed
The oil refinery converts crude oil into valuable products and supplies. These products are made and sent to many countries abroad, in which are transported on land or along rivers and canals. Crude oil is then arranged and categorized into segments by fractional distillation. Raw crude oil, or unprocessed crude oil, is not normally beneficial in most industrial applications. Low sulfur crude oil has been valuable as a burner fuel to construct steam for the force of seagoing vessels. The lighter elements have the ability to construct explosive and dangerous vapors in the gas tanks. There are extremely hazardous, and are often used in war ships. The remaining hydrocarbon molecules are filtered from crude oil and used towards lubricants, feedstock, plastics, and fuels.