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Our Breakthrough Technology

oxidises sulphur-containing hydrocarbon molecules (including sulphur-containing polyaromatic hydrocarbon compounds) in hydrocarbons to their respective sulphone, which can then be separated and concentrated using extraction technology, due to the polar nature of the oxidised molecules.


In so doing, the resultant hydrocarbon has a low/ultra-low sulphur content, reduced polyaromatic hydrocarbon content, reduced nitrogen content and increased stability by virtue of the oxidation of reactive hydrocarbon compounds.

Ultrex® Units can be constructed in standard sizes of up to 40,000 barrels per day processing capacity as a single train, with multiple trains suitable for larger capacities.


Ultrex® Units can be located within a refinery precinct or at a tank farm or pipeline terminal.

Ultraclean Technology has developed a solution for the separation of sulphur from hydrocarbons, comprised of a patented chemical process (Ultrex®) and a proprietary liquid phase transfer catalyst (PTC). The Ultrex® solution is a commercial scale oxidative desulphurisation process that


The functional concept of the Ultrex® process is based on the philosophy that the Sulphur bearing hydrocarbons molecules are oxidised to their dioxide equivalent using an oxidation process. 

When these Sulphur species are oxidised to their dioxide equivalent (Sulfones), the sulphur bearing molecules exhibit:

  • Higher boiling point – allowing the sulphur species to be concentrated and removed through distillation

  • Increased Polarity – allowing the sulphur species to be extracted using a polar solvent



The oxidation of sulphur species is difficult due to electron density and sulphur atom position on the parent aromatic ring.   


Due to this, the oxidation process requires a strong oxidant media to transform the sulphur portion of the aromatic molecule to its sulfone equivalent.   


An active source of oxygen is required in the process, such as peroxide.   


Active oxygen needs to be transported from the aqueous oxidant media into the oil phase, which is achieved via a phase transfer catalyst (PTC) plus vigorous mixing.

Following oxidation, the sulphone molecules are highly polar and can be removed from the parent oil using a polar solvent in a liquid-liquid extraction process.


The polar solvent ‘strips’ the sulphones from the oxidised oil in a counter-current extractor column, concentrating these in a high-sulphur residual product. 


A water wash or steam strip is performed on the stripped oil to remove any residual solvent, leaving an ultra-low or low product depending on required specification.  The used solvent is regenerated and reused in a continuous process.


For some heavy residual oils, a distillation step is used in lieu of liquid-liquid solvent extraction; producing a low sulphur fuel oil and concentrating the sulphones and asphaltenes in a bitumen extender by-product.

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Ultraclean ‘Beta’ unit - 1,000 bpd

The Ultrex® solution has been successfully demonstrated at a scale of 1,000 barrels per day in a pilot unit to separate low sulphur diesel into ultra-low sulphur diesel plus a high sulphur residue product suitable for use as off-road non-taxable diesel or as marine fuel (0.5% wt)

Competitive Advantage vs hydrodesulphurisation (HDS)

Simpler, cleaner, and safer….


  • Significantly lower carbon footprint than HDS ~ 80% reduction in CO2 intensity

  • •Ability to electrify the process energy for use of green electricity

  • Higher uplift in cetane than HDS - higher cetane = cleaner fuel burn = lower emissions

  • Larger reduction in aromatics than HDS - lower aromatics = less emissions of a known carcinogen

  • Limited process waste - Minimal wastewater vs HDS waste (catalyst and toxic hydrogen sulphide rich water & gas waste)


  • Significantly lower capital cost than HDS - estimated >75% reduction in Capex

  • Significant sulphur reduction - Up to ~ 99.9%.

  • No use of hydrogen, so no need for access to natural gas to manufacture hydrogen

  • Significantly reduced electricity usage


  • Much simpler than HDS - HDS 5 stage process vs Ultrex® 2 stage process

  • Much safer than HDS - 80% reduction in temperatures / 94% reduction in pressures 

  • Flexible installation - Can be deployed in both refineries and tank farms

  • Modular design simplifies installation

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