Text of PRODUCTION OF GASOLINE Done by: Naser torKi Al-Enazi Abdulrahman Sami Alqattan Mohammed Mahdi...
PRODUCTION OF GASOLINE Done by: Naser torKi Al-Enazi Abdulrahman Sami Alqattan Mohammed Mahdi Bouftain Abdullah Abdulaziz Alfahad Ahmed Haji Al-Mutairi
Abstract RRefinery gases will be taken from the refinery units and mostly these gases are rich with liquids (NGL) TThe C2, C3 and C4 are types of the (NGL),and this project is concerned in C4 so the C3 and C2 even the gas C1- will be converted to C4 TThe waste CO 2 stream can be converted instead of ejecting it to the environment -Satabier reaction to methane AAlkylation
Introduction Refinery gas Natural gas liquids recovery processes Especially if the gas is very rich- a source of revenue- The specific processing needed depends on percentage of heavier hydrocarbons, efficiency to recover them, impurities to be removed.etc Liquids can be sold separately or as feedstock for petrochemicals or further refining to preduce high octane number gasoline (which is our project)
History Can be related with the ancient time related to the discovery of the natural gas. The Chinese were the first people to discover the value of natural gas But the recovery of its liquids especially when it is rich was not recognized The natural gas was first commercialized in 1790, until 1900s In 1910, Dr.Walter Snelling, the U.S. Bureau of Mines, who investigated gasoline Why it evaporated so fast and discovered light HC
History The evaporating gases were propane, butane, and other light hydrocarbons. Prepared a still that could separate the gasoline into its liquid (C5+) and gaseous components (NGL) Clearly these gaseous components can be liquefied and then can be called NGL Since they are in vapor phase at the ambient temperature and pressure. the second important source of NGL, which are the refining gas emitted from different units of refineries plants
History Arabs have been producing large quantities of refinery separator off-gases to stabilize petroleum fractions Most are flared and are not utilized in the recovering Lean oil absorption process was developed in the 1920s but has low efficiency in separating C2 Refrigerated lean oil absorption was developed in the 1950s to increase the yield of C2 Recently developed and most widely used nowadays cryogenic refrigeration.
History Alkylation is a twentieth century refinery innovation (in the late 1930s)
World Production and Consumption Production (Thousand barrel per Day ) Country Ran k 1738.78United States1 1427.00Saudi Arabia2 685.21Canada3 427.41Mexico4 416.61Russian Federation5 309.93Algeria6 300.00 United Arab Emirates 7 286.21Norway8 280.00Qatar9 215.00Venezuela10 142.30United Kingdom11 130.00Kuwait12
Uses Uses for the butane: It is used as lighter fuel, cooking and camping. And the pure butane like isobutene can be used as refrigerants, and it can be mixed with propane and other hydrocarbon to make Liquefied petroleum gas as fuel for vehicles. Uses for the gasoline: It is used as a solvent, and it is used as fuel for cars and can be used to produce rubber, dyeand is used in the production of other chemical such as polymers, plastic and phenol. Uses for the NGL: NGL is cleanest burning fossil fuel, it produces less emissions than oil and because of it used in many things that need energy specially that need burring, it is used as fuel for cars, cooking, camping and heating.
Feed stock and product description Hydrogen:
Process Flow Sheets Process flow diagram 1:
Process flow diagram 2:
Process flow diagram 3:
Major equipments in flow sheets H 2 S removal: To remove H 2 S from a gas of light hydrocarbons, various methods are used like chemical adsorption and physical adsorption. Chemical adsorption is chosen because the gas feed is very rich with heavier hydrocarbons so that they will not be dissolved.
Demethanizer Demethanizers used as a stripping columns to remove methane from the NGL Demethanizers also act as the final cold separator, a collector of cold NGL liquids, and source of recovering some refrigeration by cooling warm inlet streams. Demethanizer usually operates at a conditions of (-115 to -110 C) and (200 to 400 psig).
Deethanizer: A distillation process used to separate ethane as overhead vapor product from the propane and traces of heavier hydrocarbons. Due to purity specifications of butane, it recommended to recover ethane highly from the feed (may reach >90%), and this is done through external refrigeration and expansion although it will cost much.
Depropanizer: Its diameter is smaller than the debutanizer, also taller because of larger number of trays required to make a sharp cut between the butane and propane fractions. The operating pressure is (16-19bars), reflux ratio is (1.8-3.5), Number of trays is (30-40) and tray efficiency (80-90%).
Debutanizer: Curtain temperature and pressure at feed equilibrium conditions are selected to ensure that the product meets the volatility and products purity specifications.
Fischer-Tropsch Reactor: C1 C3 can be converted to Butane by using Fischer- Tropsch reactor. The hydrocarbons are fed to dehydrogenation process which convert it to carbon monoxide and hydrogen at a conditions of 300-700 C and 2-4 bar, Then the rich carbon monoxide is sends to Fischer-Tropsch reactor which preferred operates at 200- 270 C and 500-3000 Kpa using a supported catalyst comprising a metal oxide or sulfide of Mo, W, Re, Ru, Ni plus an alkali earth metal.
Ethane to Butane: Ethane is converted to LPG in a combination process which comprises directly passing olefin effluent from thermal cracking of Ethane over a special Crystalline aluminosilicate zeolite of the ZSM-5 type and recovering C3+ Hydrocarbons.
Carbon dioxide to Methane: Carbon dioxide can be converted to Methane by adding Hydrogen in stoichiometric ratio to the CO2 feed and then fed to the reactor at 400 C and 1 atm with a catalyst Rhoduim-alumina according to the reaction: CO2 + 4H CH4 + 2H2O
process convert methane to ethane: there are invention to relates methane to producing ethane with catalyst that selected from metal hydride or metal organic compounds.It is single step process with non-oxidition catalyst this reaction in tempreture range preferred at 20 C to 500 C at total absolute pressure 0.1 Mpa to 50 Mpa to product ethane with high selectivity.
Alkylation: alylation is the process to produce gasoline range materials such as octane and iso-octane from reacting isobutane with olifins such as butene, propelene. using the AlkyClean process which employs a zeolite acid catalyst. the reaction takes place in two step reactors, first nC4 is converted to butene (olefin). then preheated and fed to the second reactor (in the presence of iC4) in liquid phase reaction, the reaction is operated at temperature (122-194C)
Comparison between the process flow sheets Process flow diagram 1: 6 distillations are used in Process flow diagram 1 and 5 reactors. Using a lot of distillations means more cost. To maximize production of butane 3 Fischer-Tropsch reactor are used. The advantage of this diagram is that it needs a lot of energies to refrigerate the feed for separate C1 and C2.
Process flow diagram 2: 6 distillations are used in Process flow diagram 2. C1, C2 and C3 are fed to a series of reactors to maximized Butane production instead of separating them. Many recycled stream are used in this Flow diagram. Recycled exit Hydrogen and the unreacted (C1,C2,C3) from the series of reactors. Separating C3+ from C4-C5 from the first is more preferred because it easier and more economical. The advantages of this sheet are it is fed into a series of reactors that reduce the conversions of product in each reactor and has a side product.
Process flow diagram 3: 6 distillations are used in Process flow diagram 3. This flow sheet is preferred because it is using the famous Fischer-Tropsch reactor that maximized the production of liquid butane. Also the recycled (C1, C2, C3) and Hydrogen are increases the production of liquid Butane (C4). The disadvantages of this sheet is Fischer-Tropsch reactor does not convert all feed into C4 and it is produce water that cause freezing in the plant.