Crude oil atmospheric and vacuum distillation plant

Brief Description of Crude Oil Refining

Crude oil refining is an industrial process that transforms raw, unprocessed crude oil into useful products like gasoline, diesel, jet fuel, heating oil, lubricants, asphalt, and petrochemical feedstocks. The core process typically involves three main stages:

1. Separation (Distillation): Crude oil is heated in a furnace and fed into a tall distillation column. Components separate based on their boiling points:

* Lighter fractions (like gases, naphtha for gasoline) rise to the top.

* Medium fractions (like kerosene/jet fuel, diesel) condense in the middle.

* Heavier fractions (like gas oil, lubricating oil base stocks) condense lower down.

• The heaviest residues (asphalt, tar) collect at the bottom.

2. Conversion: Heavier, less valuable fractions from distillation are transformed into lighter, higher-value products using chemical processes:

Cracking: Breaking large hydrocarbon molecules into smaller ones (e.g., Fluid Catalytic Cracking - FCC, Hydrocracking).

Uniting/Combining: Combining smaller molecules into larger ones (e.g., Alkylation).

Rearranging: Changing molecular structure to improve quality (e.g., Reforming to create high-octane gasoline components).

3. Treating: Refining intermediate and final products to remove impurities (like sulfur, nitrogen, metals) and improve stability and performance. Common methods include:

Hydrotreating: Using hydrogen and catalysts to remove sulfur (desulfurization), nitrogen, and saturate molecules.

Sweetening: Removing foul-smelling sulfur compounds (mercaptans).

The refined products are then blended according to specifications and sent for distribution and sale. Modern refineries are complex, integrated facilities continuously optimizing these processes to meet market demands and environmental regulations.

Plant production process index control (the following data is the approximate range, not accurate data)

Description

The unit is composed of heat exchange part, electric desalting part, initial distillation part, atmospheric distillation part, vacuum distillation part.

Product scheme

Unit product plan is reforming material(naphtha)—Aviation kerosene—diesel—Wax oil hydrocracking/refining program.

The main products are as follows：

Naphtha——as a catalytic reforming raw material.

First side oil line of atmospheric column——As a raw material for aviation kerosene hydrogenation.

second side oil line of atmospheric column——As a raw material for diesel hydrogenation.

Third side oil line of atmospheric column——As a raw material for diesel hydrogenation.

Vacuum column top line oil——As a raw material for diesel hydrogenation.

Vacuum column first line oil——As a raw material for diesel hydrogenation.

Vacuum column second line oil——As wax oil hydrogenation/cracking raw material.

Vacuum column third line oil——As wax oil hydrogenation/cracking raw material

Vacuum column fourth line oil——As wax oil hydrogenation/cracking raw material

Vacuum residual oil——As a raw material of heavy oil catalytic/coking/dissolving/oxidizing asphalt

Frequently Asked Questions (FAQ) About Crude Oil Refining Equipment

1. What is a crude oil refinery ?

A refinery is an industrial facility where crude oil is processed and refined into useful products (e.g., gasoline, diesel, jet fuel, chemicals) through physical separation, chemical conversion, and purification.

2. What are the key units in a refinery ?

Core units include:

- Atmospheric Distillation Unit (ADU): Separates crude oil into fractions (naphtha, kerosene, diesel, etc.) based on boiling points.

- Vacuum Distillation Unit (VDU): Further processes heavy residues from ADU under reduced pressure.

- Fluid Catalytic Cracking Unit (FCCU): Breaks down heavy hydrocarbons into lighter fuels (e.g., gasoline) using a catalyst.

- Hydrotreater: Removes sulfur, nitrogen, and metals using hydrogen to meet environmental standards.

- Reformer: Converts low-octane naphtha into high-octane gasoline blendstock.

• Coker: Thermally cracks heavy residues into lighter products and petroleum coke.

3. Why is distillation the first step?

Crude oil is a mixture of hydrocarbons with varying boiling points. Distillation separates it into fractions ("cuts") for targeted processing downstream.

4. How does an FCC unit work?

Heavy gas oil is mixed with hot catalyst powder, cracking it into lighter molecules. Spent catalyst is regenerated by burning off coke deposits, then recycled.

5. What is the purpose of hydrotreating?

Hydrotreating removes impurities (sulfur, nitrogen) to:

- Meet environmental regulations (e.g., ultra-low-sulfur diesel).

- Protect catalysts in downstream units from poisoning.

• Improve product stability.

6. What causes corrosion in refinery equipment?

Corrosion results from:

- Sulfur compounds (e.g., H₂S in sour crude).

- Organic acids (naphthenic acids).

- Chlorides in crude or cooling water.

Materials like stainless steel/cladding and corrosion inhibitors are used to mitigate damage.

7. What is "coking," and when is it used?

Coking is a severe thermal cracking process that converts heavy residues into lighter products and solid petroleum coke. It’s used when residues cannot be economically processed elsewhere.

8. What are heat exchangers used for?

Heat exchangers recover heat between process streams (e.g., heating crude oil before distillation using hot product streams), significantly improving energy efficiency.

9. Why are compressors critical?

Compressors handle gases (e.g., hydrogen for hydrotreaters, refinery fuel gas). Failure can shut down entire units. Reliability is ensured via redundancy and rigorous maintenance.

10. What safety systems protect refineries?

Pressure Relief Valves (PSVs): Prevent overpressure in vessels/pipes.

Flare Systems: Safely burn emergency hydrocarbon releases.

Gas Detectors: Monitor leaks of H₂S, hydrocarbons, or combustibles.

Firewater Systems: Suppress fires via deluge sprinklers/foam.

11. How is refinery equipment maintained?

Turnarounds: Full plant shutdowns every 3–6 years for inspection, cleaning, and repairs.

Predictive Maintenance**: Uses vibration analysis, thermography, and corrosion monitoring to prevent failures.

12. What environmental controls are used?

Scrubbers: Remove SO₂ from flue gas (e.g., FCC regenerator off-gas).

Wastewater Treatment: Removes oil, chemicals, and solids before discharge/reuse.

Carbon Capture: Emerging technology to reduce CO₂ emissions (e.g., from hydrogen plants).

13. Why do refineries need hydrogen?

Hydrogen is essential for:

- Hydrotreating (to desulfurize fuels).

- Hydrocracking (to upgrade heavy oils into light fuels).

It’s produced onsite via steam methane reforming (SMR).

14. Can refineries process all types of crude oil?

No. Refineries are optimized for specific crude grades (e.g., light sweet, heavy sour). Switching crude types may require adjustments or equipment upgrades.

15. Where can I learn more about refinery technology?

- Industry guides: API (American Petroleum Institute), UOP (Honeywell).

- Organizations: AFPM (American Fuel & Petrochemical Manufacturers).

- Publications: Hydrocarbon Processing，Oil & Gas Journal.