• HOLL-REACTORS® are flow-through and make tank-reactors obsolete
  • HOLL-REACTORS® can accelerate chemical reactions by orders of magnitude
  • Reactor mixing surfaces can be catalyst coated with Pd (Palladium), Pt (Platinum), etc. eliminating the need to mix in catalytic agents and then recollect those agents afterward.
  • HOLL-REACTORS® can achieve highest selectivities and yields, unattainable with any other reactor
  • HOLL-REACTORS® are highly resistant to plugging and are continuously self-scouring
  • HOLL-REACTORS® are protected by US Patents 7,780,927 and 6,752,529
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Holl-Reactors® are used in
  • ultra-fast synthetic chemical processes, as well as oxidative petroleum desulfurization reaching below 5 ppmimg-13
  • ultra-fast emulsifications
  • and planetary paste-mixing

Visualizing Micromixing and -reacting
of highly viscous liquids in a Holl-Reactor®


Holl-Reactors® can be used autoclaved under controlled atmosphere


The Holl Desulfurization of Petroleum Fuel
- A Novel Oxidative Desulfurization Method

Removal of sulfur from motor fuels to 5 ppm is planned to be legislated in the US, EU and Japan but achieving it economically is still an elusive target. Recently, an initial breakthrough has been reached using the Holl-Reactors® technology at the Oregon State University labs, where desulfurization of dibenzothiophene (DBT) and thiophene was selected for testing because it is known to be very time consuming, difficult and expensive to carry out conventionally. Surprisingly, unprecedented DBT conversion rates (see Figure on the right) were achieved. The rate of DBT conversion accomplished in the Holl-Reactors® was several orders of magnitudes faster into the 5 ppm range – without using any catalysts - than any similar reaction reported in the open literature. The desulfurization of dibenzothiophene in the Holl-Reactors® used H2O2 as the oxygen source in a two-phase reaction process at room temperature (H2O2 in an aqueous phase and hexane containing various amounts of sulfur in DBT as the oily phase).


This breakthrough experiment in Holl-Reactors® in the chemical reaction engineering laboratory of Oregon State University (OSU) under the supervision of Prof. Goran Jovanovic and recently retired Dr. Octave Levenspiel demonstrated that the removal of sulfur from motor fuels by oxidation is particularly attractive when carried out in the Holl-Reactors® in contrast to the expensive classical hydrodesulfurization processes. Sulfur compounds in motor fuels occur predominantly in three different forms: dibenzothiophene, thiophene and H2S. While H2S removal from fuels is a somewhat easier process, the sulfur in thiophene based compounds is much more difficult to remove in standard refinery processes. Therefore most of the sulfur found in commercial motor fuels is thiophene- and dibenzothiophene based sulfur. The state of the art hydrodesulfurization process of today’s typical refineries is incapable of removing sulfur from motor fuels to the required 5 ppm level. Hydrodesulfurization using the Holl-Reactors® can be the most efficient and most cost reducing method of modern petroleum fuel desulfurization.

How does it work?

Holl-Reactors® features:
  • Continuously self-cleaning
  • Highly resistant to plugging
  • Absolutely free of product contamination
  • Reactor surfaces are chemically inert
  • The reactor design disables any potential reagent contamination
  • Patented heat transfer technology ensures best possible thermal control
In the Holl-Reactors® there are:
  • No seals
  • No bearings
  • No product contamination
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For additional information, please contact Richard Holl directly at

Richard Holl, CEO
Holl Partners LLC
Oxnard, CA 93036