The Green Leaf HCCO® (Homogeneous Charged Continuous Oxidation) Process applies to oil shale, oil sands, coal, and other carbon-rich ores.
Key Elements of the Process
  • Direct, down-flow zone heating in steel drum retorts, with the capture of heat in successive beds for high thermodynamic efficiency
  • Controlled, low-temperature oxidation of hydrogen-rich produced gas supplies heat and power for internal use and generates concentrated CO2 for sequestration and enhanced oil recovery (EOR) in nearby oil fields
  • Energy self-sufficient, resulting in no demand for imported fuel or electricity
  • Density beneficiation increases the effective grade (30+% in the Uinta Basin) of the processed organic-rich ore for improved economics
  • Creates lighter oil than traditional retorts but heavier than in-situ
  • The process requires no water to produce oil and allows for the collection of produced water
  • Primary water use is for dust control in the mining process
Intellectual Property
  • 30+ U.S. patents and associated foreign patents


HCCO® Process

  • Selective mining and beneficiation separate strategic materials / rare earth elements from the oil shale and provide a rich feedstock for the retorting process
  • Organic-rich ore is heated to pyrolysis by controlled low-temperature oxidation of the produced hydrogen-rich gas
  • Heat is transferred from the gas to the rubblized shale bed
  • Retort drums are ganged together so the ‘batch’ process of a single drum is made ‘continuous’ in heat and fluid movement, gaining the advantages of both types of processes
  • Cool ore beds downstream act as condensers and for heat recovery, adding to the efficiency of the process
  • High yield, good quality oil (~24° API) with significant middle distillate content
  • Concentrated CO2 is sequestered or used for enhanced oil recovery in nearby oil fields
  • Spent ore (post retorting) is re-deposited in the mined pit for immediate reclamation