The goal of the Interra project was to develop a low-cost, pyrolysis-based biomass conversion technology, known as the Reciprocating Reactor, to produce renewable natural gas and biochar. The Reciprocating Reactor is designed to convert biomass into renewable natural gas at higher efficiencies compared to other thermal conversion technologies. However, the project encountered major technical challenges including in maintaining the required operating pressure in the first prototype version of the technology and the effect of significant nitrogen dilution on pyrolysis producer gas. While mechanical testing confirmed that, under ambient conditions, the material handling system was able to push the maximum designed rate of biomass through the reactor, operational testing revealed significant issues with multiple systems, including the auger design, biomass intake system, and combustion flare. The design failures detected during operation testing drove the need for iterative experimental testing and ongoing repairs to address the technological challenges of effectively operating at the desired system temperature and throughput rate. Further research, component development and refinement, and small-scale testing is needed to validate full performance and stability of the system prior to pilot-scale testing and renewable natural gas production.
