Journal of Advanced Chemical Engineering

Technical Process of Petroleum Refinery

Thanmai Allu^* Department of Chemical Engineering, Andhra University, Visakhapatnam, Andhra Pradesh, India
^*Correspondence: Thanmai Allu, Department of Chemical Engineering, Andhra University, Visakhapatnam, Andhra Pradesh, India, Email:

Received: 02-Mar-2022, Manuscript No. ACE-22-16328; Editor assigned: 04-Mar-2022, Pre QC No. ACE-22-16328(PQ); Reviewed: 18-Mar-2022, QC No. ACE-22-16328; Revised: 21-Mar-2022, Manuscript No. ACE-22-16328(R); Published: 28-Mar-2022, DOI: 10.35248/2090-4568.22.12.217

Description

Petroleum refineries convert crude oil into petroleum products for use as transportation fuels, heating fuels, paving roads, generating power, and as chemical feedstocks.

Refining is the process of breaking down crude oil into its constituent components, which are subsequently reconfigured into new goods. Petroleum refineries are large, complicated, and costly industrial plants. There are three basic phases in every refinery:

• Separation

• Conversion

• Treating

Separation

Crude oil is piped through heated furnaces in modern separation. The liquids and vapors that arise are pumped into distillation units. Atmospheric distillation units are used in all refineries, while vacuum distillation units are found in more complicated refineries.

The liquids and vapors inside the distillation units are separated into petroleum fractions based on their boiling points. On the bottom are heavy fractions; while on the top are light fractions.

Gasoline and liquefied refinery gases, for example, evaporate and climb to the top of the distillation tower, where they condense back to liquids. Medium-weight liquids, such as kerosene and distillates, remain in the distillation tower's midsection. Gas oils, which are heavier liquids, separate towards the bottom of the distillation tower, while the heaviest fractions with the greatest boiling points separate at the top.

Conversion

Heavy, lower-value distillation fractions can be processed further into lighter, higher-value products like gasoline after distillation. This is where fractions from the distillation units are converted into streams, which are then processed into finished products.

Because it employs heat, pressure, catalysts, and sometimes hydrogen to fracture heavy hydrocarbon molecules into lighter ones, cracking is the most extensively utilized conversion process. One or more tall, thick-walled, rocket-shaped reactors, as well as a network of furnaces, heat exchangers, and other vessels, make up a cracking unit. Fluid catalytic cracking units and hydrocracking/hydrocracker units are two types of crackers that may be found in complex refineries.

Cracking isn't the only way to convert crude oil. Rather than breaking molecules, other refining operations rearrange them to add value.

Alkylation, combines some of the g aseous mixtures and by products of cracking to produce gasoline components. The procedure, which is effectively cracking backwards, takes place in a large, horizontal vessel and tall, skinny towers.

Reforming converts naphtha, a light, low-value fraction into high-octane gasoline components using heat, moderate pressure, and catalysts.

Treatment

During the final treatment, the finishing touches are applied. Refinery technicians meticulously blend a variety of streams from the processing units to generate gasoline. The gasoline mix is determined by the octane level, vapor pressure ratings, and other unique considerations.

Treatment entails eliminating or greatly lowering caustic or polluting compounds, particularly sulphur. Sulfur emission limits in the European Union are extremely strict. Since January 1, 2009, sulphur levels in gasoline and diesel sold in Europe have been limited to 10 milligrams per kilogram. These procedures are intended to improve air quality and increase the efficiency of catalytic converters that treat exhaust gas. Desulfurization, or sulphur removal, is carried out on diesel at a temperature of 370°C at a pressure of 60 bars. The hydrogen in the process reacts with the sulphur to generate hydrogen sulphide, which is subsequently processed to remove the sulphur, which is used in industry.

To remove thiols, also known as mercaptans, kerosene, butane, and propane are washed in a caustic soda (sodium hydroxide) solution. Sweetening is the term for this procedure.

The resistance of a fuel to detonation, which causes engine knocking, is measured by its octane rating.

Automobile fuel treatment

Automotive fuels must also be treated to raise their octane rating, which is a scale from 0 to 100 that measures a fuel's resistance to explosion. The engine will eventually be irrevocably damaged if the octane grade isn't high enough. To avoid this, the octane rating must be increased to 95 or 98.

The process of producing high-octane fuels is known as catalytic reforming. The chemical reactions occur at 500°C and a pressure of 10 bar during catalytic reforming, which uses platinum as a catalyst. Some naphthenic hydrocarbons (saturated cyclic hydrocarbons) are converted into aromatic hydrocarbons (unsaturated cyclic hydrocarbons), which have a substantially higher octane value. Alkylation and other chemical processes boost the octane rating as well.

The uses of refined petroleum products

Each refined petroleum product derived from crude oil has a distinct application:

• Liquefied petroleum gas (LPG), commonly known as butane and propane, is a type of gas that can be used as a vehicle fuel or bottled in bottles for use in the home;

• For motor vehicles, gasoline and diesel are utilized as fuels;

• Jet fuel is made from kerosene;

• An important petrochemical feedstock is naphtha;

• Buildings are heated using heating oil;

• Lubricants are made from base oils;

• Roads are paved with asphalt, also known as bitumen.

Storage

Both arriving crude oil and outgoing finished products are temporarily held in massive tanks on a refinery's tank farm. The final products are transported from storage tanks to other locations around the country by pipelines, railroads, and vehicles.