PRODUCTION OF GASOLINE

Done by:

Naser torKi Al-Enazi

Abdulrahman Sami Alqattan

Mohammed Mahdi Bouftain

Abdullah Abdulaziz Alfahad

Ahmed Haji Al-Mutairi

Abstract

Refinery gases will be taken from the refinery units and mostly these gases are rich with liquids (NGL)

The 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

The waste CO2 stream can be converted – instead of ejecting it to the environment -Satabier reaction to methane

Alkylation

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

Rank

CountryProduction (Thousand barrel per Day )

1United States1738.782Saudi Arabia1427.003Canada685.214Mexico427.41

5Russian Federation416.616Algeria309.937United Arab

Emirates300.00

8Norway286.219Qatar280.00

10Venezuela215.0011United Kingdom142.3012Kuwait130.00

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:

Carbon dioxide:

Hydrogen sulfide:

Methane:

Ethane:

Propane:

I-Butane:

Butane:

I-Pentane:

Pentane:

Hexane:

Octane:

Process Flow Sheets

Process flow diagram 1:

Process flow diagram 2:

Process flow diagram 3:

Major equipments in flow sheets

H2S removal:   To remove H2S 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.

Economical analysis

The feed gases are taken from the waste of the refineries. So It is almost comes from free, instead of get rid of these waste, converting it into a value gasoline. Gasoline price on 17-Feb-2012 was 31.062 $/lb.

Gasoline price is increasing from discovering it until now. At 1990 the value was 9.944 $/lb, at 2000 was 12.633 $/lb and at 2010 the value was 23.914 $/lb. it.

The average increasing per year is 2.5 $/lb, so it is predicting in 2020 the price of Gasoline will be 47.65 $/lb.

Conclusion:

Process flow diagram 3 is the recommended sheet because it maximize the production of the Butane, it is more economical by without using refrigerators and it has many recycle streams. Plant for production of liquid Butane is absolutely profitable because it comes from the waste of the refinery gases that make pollution for the environment. Adding a reactor to convert liquid Butanes into Gasoline will make this plant more profitable that prevent a major source for fusel fuel.

Thank you for listening