Selective Extraction of Asphaltenes

About SELEX-Asp

SELEX-Asp is a patented, low-complexity, cost effective, and commercially proven technology that is backed by over 30 years of research. It is a solvent-based separation process that operates under the principles of supercritical fluid extraction and fractionation.


Globally, there is 36,500 bpd of installed, operating SELEX-Asp processing capacity. The largest single unit has a capacity of 20,000 bpd.


An additional 35,000 bpd of SELEX-Asp processing capacity has been licensed in North America.

Why license SELEX-Asp?

SELEX-Asp is a transformative technology that is more environmentally friendly and economical than conventional residue treatment processes. Through a proprietary vapor-solid separation system, SELEX-Asp is used to produce asphaltene-free premium feedstocks without the need for expensive thermal or catalytic processes, such as coking and ebullated bed hydrocracking.


It is the only commercial technology that can cleanly and selectively remove virgin asphaltenes as solid granules from petroleum residues, which can be safely and easily handled. SELEX-Asp also maximizes the yield of deasphalted oil that can be subsequently processed using low-cost packed bed hydroprocessing.

SELEX-Asp in a Refinery

Yuan, B., Tang, Z., Chung, K.H., Wei, Q., Sun, X., Zhao, S. and Xu, C., “Asphaltenes Extraction Treatment Yields Advantaged Hydroprocessing Feedstock”, Oil & Gas J., June 6, 2016, 70-77.

Midstream Deployment

SELEX-Asp can be implemented near the production source, serving as a key process in an upgrading or partial upgrading facility. Removal of asphaltenes using SELEX-Asp drastically reduces the viscosity and increases the value of heavy crude. This allows for pipeline transportation with significantly reduced diluent requirements, which reduces pipeline transportation costs of heavy oil while liberating additional pipeline capacity in existing infrastructure. SELEX-Asp improves the netback value and increases the market share of heavy crude.

Expands a Refiner's Flexibility to Process Heavy Crudes

Asphaltenes are the only refractory oil constituent to refinery processing. Once asphaltenes are removed, the remaining oil can be processed in conventional refining processes. SELEX-Asp expands the refiner's flexibility by turning low-value, difficult-to-process heavy crude fractions and derivatives into generic refining feedstocks. SELEX-Asp allows a refiner to economically produce a product slate that is compliant with upcoming IMO 2020 low-sulfur regulations.

While SELEX-Asp increases the yield of fungible oil and reduces the environmental footprint of an existing refinery, it also reduces hydrogen and catalyst consumption, which are major operating costs for processing heavy feedstock. SELEX-Asp can be retrofitted into existing refineries by replacing conventional solvent deasphalting, visbreaking, and similar processes. SELEX-Asp can also be used to simplify and debottleneck your current residue treatment operations.

Competitive Advantage

SELEX-Asp offers the following advantages over conventional alternatives:


  • Maximize liquid yield from petroleum residue

  • Reduce capital and operating costs

  • Smaller and simpler extractor design

  • Higher energy efficiency

  • Lower solvent requirements

  • Deeper and cleaner separation

  • Enhanced mass transfer in extractor

  • Asphaltenes removed as dry granules and easy to handle

  • Creates feedstock suitable for the production of low sulfur consumer products

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SELEX-Asp Projects


Well is actively engaged in licensing the SELEX-Asp process to the greater market. Commercially operating and licensed SELEX-Asp units currently exist in Asia-Pacific and North America.

SELEX-Asp for

Canadian Stakeholders

  • Increased Product Value

  • Increased Effective Pipeline Capacity

  • Expanded Markets

SELEX-Asp for

Global Stakeholders

  • Increase Refining Margins

  • Add Processing Flexibility

  • Lower Carbon Footprint

Interested in licensing SELEX-Asp?

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