Interra Reciprocating Reactor to Produce Low-Cost Renewable Natural Gas

Interra's Reciprocating Reactor is an efficient method for producing RNG from green waste

Interra Energy, Inc.


San Diego, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Result

Researchers completed some hot testing under this project and expect that the testing phase will be completed in early November 2015.

The Issue

A root technical problem associated with all pyrolysis-based biomass conversion technologies is the low heat of reaction of pyrolysis and the resulting inability to create a thermally self-sufficient continuous reaction. Current methods of addressing this all have fatal drawbacks that substantially and negatively affect the overall viability of the technology in the Californian Market. This Project proposed the demonstration of a unique pressurized pyrolysis biomass reactor that overcomes these shortcomings.

Project Innovation

The purpose of this project was to design, build and demonstrate the use of a reciprocating reactor by producing the highest quantity of biochar on an input/output basis and the highest end-quality gas on an energy density basis (btu/scf) of all publicly known continuous feed thermochemical conversion technologies without the use of chemical catalysts, separate gas upgrading processes, external heat input, or air/oxygen injection for combustion heat makeup.

Project Benefits

The Reciprocating Reactor is able to surpass a thermal efficiency threshold in biomass pyrolysis and achieve a continuous and self-sustaining biomass pyrolysis reaction without requiring combustion or oxidization reactions internally or externally by uniquely recovering the heat potential stored within the phase change of steam to liquid water. This will reduce energy usage in the production of RNG. Additionally, this project generates the co-product biochar.

Energy Security

Energy Security

The production of renewable natural gas from green waste through this project will provide California with a viable and low emission fuel option. Increased access to RNG within the state reduces dependency on other imported fuel options with higher carbon footprints.

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