Technoeconomic and emissions evaluation of mobile in-woods biochar production (vol 223, 113305, 2020)

The respective net GHG emissions for two systems with and without dryer are 5.43 and 7.94 ton CO2 eq/ton biochar-C. However, when the emissions from natural decay or burning of slash (if left unprocessed) are accounted as avoided emissions, the systems with and without dryer result in the respective GHG emission benefits of 2.94 and 1.18 ton CO2 eq/ton biochar-C. The systems reach their break-even point when CO2 emission benefits are valued at a minimum of 193-486 USD/ton CO2. Highlights Proposed systems breakeven between 567 and 573 USD/ton biochar-C with no CO2 benefits. Oxidative torrefaction makes reactor auto-thermal and avoids a separate dryer. Systems with and without dryer give benefits of 2.94 and 1.18 ton CO(2)eq/ton biochar-C. CO2 emission benefits value range between 193 and 486 USD/ton CO2 for breakeven. For entire forest, proposed approach results in benefit of 0.41 ton CO2/ton of slash.

Automated summary

The net GHG emissions for two systems with and without dryer are 5.43 and 7.94 ton CO2 eq/ton biochar-C, but when accounting for avoided emissions from natural decay or burning of slash, the systems result in emission benefits of 2.94 and 1.18 ton CO2 eq/ton biochar-C respectively. The proposed systems break even between 567 and 573 USD/ton biochar-C without CO2 benefits, and oxidative torrefaction makes the reactor auto-thermal while avoiding the need for a separate dryer.