Refining-Petrochemicals Integration to Maximize Chemicals Production

Introduction

• Crude oil refineries primarily produce transportation fuels.
• They also produce building blocks for the petrochemical industry like light olefins and BTX (Benzene, Toluene, Xylene).
• Due to declining demand for refined products and the growth of the petrochemical industry, refineries are under pressure to change configurations or operating conditions to produce more aromatics and light olefins.
• Integration with petrochemicals enables refiners to improve margins and sustain profitability.

Refining Configurations and Complexity

• Refinery configurations vary based on:
  • Economics.
  • Type of crude processed.
  • Quantity and type of products.
  • Quality of fuel produced.
  • Environmental regulations.
• Classes of Refinery Configurations:
  1. Topping Refinery
  2. Hydro-skimming Refinery
  3. Conversion Refinery
  4. Full Conversion Refinery
  5. Petrochemical Refinery
• Refinery Size (U.S. Department of Energy):
  • Large: $100,000$ bpd and up
  • Medium: $30,000-100,000$ bpd
  • Small: Less than $30,000$ bpd

Topping Refinery

• Includes only Atmospheric Distillation Unit (ADU).
• Produces naphtha but no gasoline.
• Designed to prepare feedstocks for petrochemical manufacture.
• Simplest refinery configuration.

Hydro-skimming Refinery

• Equipped with hydrotreating and Naphtha Reforming units.
• Hydro-skimming = Topping + Reformer.

Conversion Refinery

• Equipped with Vacuum Distillation Unit (VDU) + Catalytic Cracking Units, producing light and middle distillates.
• Cracking = Hydro-skimming + VDU + (FCC / Hydrocracking Unit).

Full Conversion Refinery

• Equipped to process vacuum residue into high-value products using Delayed Coking Process, converting fuel oil into distillates and petroleum coke.
• Coking = Cracking + Delayed Coker.

Integrated Refineries

• Equipped to upgrade LPG or Naphtha into basic petrochemicals using steam crackers and aromatics complexes.
• Integrated Refineries include: ADU, NHT, CCR, Gas FCC, VDU and DCU

Refinery Product Yield

• Product yield depends on technology.
• Hydrocrackers yield more distillate.

Worldwide Refineries

• There are 660 refineries worldwide.
• Located in 115 countries.
• Combined daily capacity of 92 million barrels per day.

Refinery-Petrochemicals Integration

Drivers of Integration

• Maximizing margins and improving competitiveness are primary drivers.
  • Cost reduction.
    • Reduced transportation costs.
    • Reduced OPEX.
    • Working capital/inventory.
    • Resourcing synergies.
  • Product revenues maximization.
    • LPG and naphtha as chemical feedstocks.
    • Aromatics-rich stream to BTX extraction.
    • Pygas, pyoil to refinery as product blend stocks.
    • Surplus hydrogen to refinery. Feed flexibility and security.
    • Feedstock optimization to meet refinery and petrochemical needs (crude vs condensate vs naphtha).
    • Choice of feed streams to petrochemical.
• New technologies and catalysts create opportunities for integration (e.g., H-Oil, LC Max, HS-FCC, DCC).

Feedstock Flexibility

• A steam cracker integrated with a refinery allows the flexibility to vary its feedstock and optimize production.
• Optimization Considerations:
  • LPG vs naphtha feed.
  • Cracker feed vs fuel sales vs refinery fuel optimization.
  • Naphtha imports vs condensate/crude processing.
  • Hydrocracker conversion optimization.
  • HCU bottoms to FCCU or steam cracker.
  • Crude C4s: Butadiene vs gasoline.
  • Pygas: Aromatics extraction vs gasoline.
  • Pyoil: Upgrade, fuel oil blending or ULSFO (IMO).
• Global ethylene production by feedstock (2017):
  • ~60% is based on liquid feedstocks (LPG, naphtha, gasoil) from refinery streams.

Integration Options

• Integration increases complexity, capital requirement, and interdependency.
• Potential exchanged streams include: Reformate, Heavy aromatics, Pygas, C5-7 raffinate, Off-gas, LPG, naphtha, gasoil, propylene, waxy bottoms, Pyoil, Hydrogen, Mixed C4’s

Evolution of Integration

• Constant evolution with significant chemical yield increase in the recent period.
  • Stage 1: Single recovery (<15% chemical yield).
  • Stage 2: Forward integration (15-25%).
  • Stage 3: Scale & portfolio complexity (25-40%).
  • Stage 4: Crude Oil-to-Chemicals (40-80%).

Common Integration Methods

• Refinery integrated with steam cracker.
• Refinery integrated with aromatics complex.
• Refinery integrated with steam cracker and aromatics complex.

Refinery Integrated with Steam Cracker

• Provides feedstock for light olefin production with valuable co-products.
• Co-products (H2, pygas) can be used for fuels production.

Refinery Integrated with Aromatics Complex

• Heavy naphtha from the refinery produces reformate (rich in aromatics) and other byproducts with refinery uses.

Refinery Integrated with Steam Cracker and Aromatics Complex

• Results in a large number of potential exchanged streams, creating higher interdependency and complexity.

Benefits of Integrated Facilities

• Joint operations and maintenance.
• Shared supporting services.
• Common safety, environmental, logistics systems.
• Varying levels of complexity depending on business models, product slate, project design, and other factors.
• Sharing includes: sites, facilities and infrastructure, joint planning & coordination, joint planning & optimization.
• Interchange includes: Key feedstock and streams, low volume streams, fuel and utilities

Regional Analysis

• Industry integration globally (Ethylene, Propylene, Para-xylene).
• Regional trends for feedstock availability, process economics, product demand, and ownership issues play a role.
• The extent of refinery petrochemical integration is not uniform across regions.
• Ethylene integration by region (%):
  • North America: Refinery integrated 51%, Non-integrated 49%.
  • Western Europe: Refinery integrated 57%, Non-integrated 44%.
  • Middle East: Refinery integrated 85%, Non-integrated 16%.
  • East Asia: Refinery integrated 79%, Non-integrated 21%.

The Refinery of the Future

Challenges Facing Refining Industry

• Variation in the character and properties of the feedstocks (i.e. heavy oils with decreasing quality).
• Stricter environmental constraints (e.g. emission control).
• Stringent product specifications.
• Expected decline in demand for oil-derived fuels.
• Increasing global demand for petrochemicals.

Requirements for Future Refineries

• Increasingly flexible in processing crudes of variable quality and new feedstocks.
• Tightly controlled to produce fuels meeting end-user and environmental legislation requirements.
• Reduce $CO_2$ emission with greater opportunity to integrate renewable energy sources.
• Integration with petrochemicals to meet the growing demand for petrochemicals.

Key Areas for Development

1. $CO_2$ neutrality (green footprint).
2. Maximal production of chemicals.
3. Zero waste generation.
4. Renewable energy integration.
5. Enhanced process efficiency.
6. Multifunctional catalyst development.

Achieving the Refinery of The Future

• Versatility to process wider range of crude oil.
• Development of economically efficient processes.
• Development of new processes enabling >80 wt.% yield to chemicals from crude oil.
• Integration of new intelligent process.
• Upgrading and cracking crude oil.
• Reduction of physical footprint.
• Reduced emissions.
• Use of renewable energy.
• Integrated carbon capture and utilization.
• Max. Chemicals Process intensification.
• Multi-functional catalysts

Key Concepts

• One of the key concepts is the direct conversion of crude oil into chemicals.
• Optimizes or eliminates energy-intensive refinery processes, generating fewer emissions.
• Results in cost savings and increased operational efficiency for the production of highly valued chemicals.
• Provides a valuable opportunity for future growth and long-term value creation to petrochemical industry.