PUREVAP™ Process

PUREVAP™ Process
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Since 2015 HPQ has been developing the PUREVAP™ Quartz Reduction Reactor (QRR) Project. A new process that will allow a One-Step production of High Purity Silicon Metal (4N+ Si), the key to a green and low-cost metallurgical production of Solar Grade Silicon Metal (SoG-Si), the ingredient that allows the conversion of the sun’s energy into electricity via solar cell.

Traditional Manufacturing of Solar Grade Silicon Metal

In order to produce solar cells, quartz must first be refined to Metallurgical grade Silicon Metal (MG-Si) using a traditional smelting process where 6 tonnes of High Purity raw products are reduced to one tonne of Mg-Si. While relatively cheap, this process has upper purity limits between 98.5% and 99.5% Si.

Achieving Purity Needed for Solar

The rapid evolution of the solar industry resulted in the chemical distillation process (Siemens Process), design for the standards of the Electronic and Computer sectors, becoming the leading process used to transform MG-Si into Polysilicium (name given to Electronic Grade Silicon Metal (EG-Si) and Solar Grade Silicon Metal (SoG-Si) produced via chemical distillation).

Because of a lack of alternatives process to produce SoG-Si, this process now controls 98% of the market even though it produces large quantities of toxic by-products and requires a massive amount of energy (72 KWh/Kg) thereby making it the largest contributor to the large environmental footprint involved in the process of solar manufacturing.

Timeline & Milestones

  • 2015 HPQ and Pyrogenesis come together for the development of the PUREVAP™ QRR
  • 2015 design and manufacturing of the GEN 1 reactor
  • 2016 GEN 1 reactor goes operational and results warrant order of a Pilot Plant
  • 2017 design and manufacturing of the GEN 2 reactor
  • 2017 GEN 2 reactor goes operational and results help in design the GEN 3 Pilot Plant
  • 2017 GEN 1 tests indicated that production of 3N+ Si is possible at commercial scale
  • 2017 Apollon Solar joined the project
  • 2018 HPQ closed on $5.2m financing
  • 2019 GEN 1 and GEN 2 test indicated that production of 4N+ Si is now possible at commercial scale
  • 2019 GEN 3 pilot commissioned during Q2
HPQ’s PUREVAP™ QRR Project will lead to the cheaper and greener production of solar-grade silicon and solar cells This will in turn cause disruptions in the status quo on GHG, CAPEX, and OPEX.


The PUREVAP™ Quartz Reduction Reactor (QRR) process, being developed in partnership with Pyrogenesis Canada Inc. (PYR), aims to offer to the world green and low-cost metallurgical approach for transforming Quartz in a Solar Grade Silicon Metal (SoG-Si) with equivalent conversion efficiency than those obtained using Polysilicium.

The PUREVAP™ QRR is a new Carbothermic process (patent pending) that allows the transformation and purification of quartz (SiO2) into high purity silicon metal (4N+ Si) in one step.

Starting in 2016 a series proof-of-concept tests were done using a lab scale PUREVAP™ QRR or GEN 1 machine and from the start, the potential of the process was validated.

Results were so promising that by August 2016 the decision was taken to build a pilot plant to demonstrate the commercial scalability of the process. As part of the process of designing and building the pilot plant, a commercial scalability proof of concept scale PUREVAP™ QRR or GEN 2 machine was build and tests are ongoing since 2017.

Using data from both GEN 1 and GEN 2 tests, PyroGenesis concluded that, even using low purity feedstock (98.84% SiO2), the carbothermic part of the PUREVAP™ QRR process should allow HPQ to produce 4N+ Si (99.99+% Si) at commercial scale.

The next step will be the start of the PUREVAP™ QRR Pilot Plant or GEN 3 schedule for mid-2019.

Reduce GHG emissions significantly disrupting GHG impact of solar manufacturing

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Lowering the CAPEX for the production of Solar Grade Silicon Metal (SoG-Si)

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Lowering operating expenses in the production of Solar-grade Silicon (SoG-Si)

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