Biomass to Coal

Low-cost biochar for gigaton-scale carbon sequestration.

About the Technology

Crop residues primarily from wheat, rice, corn, and sugarcane production amount to 5-10 billion metric tons annually, sequestering 10-15 gigatons of carbon dioxide through photosynthesis. However, this carbon is released back into the atmosphere when the residue decomposes or is burned. Converting this biomass into stable biochar through carbonization offers a solution for permanently storing the carbon for hundreds of years. Moreover, this biochar can replace most of the coal used for energy generation, boasting comparable scale and calorific value, effectively creating ""net-zero coal"" with net-zero emissions.

Traditional carbonization requires high temperatures and inert environments, making the process energy-intensive and costly. In contrast, our novel low-temperature process eliminates these requirements, significantly reducing the energy input and the reactor costs. Techno-economic analysis reveals that our biochar production costs are 4-10 times lower than traditional torrefaction methods and undercut the cost of bituminous coal. This breakthrough presents an unprecedented opportunity for gigaton-scale carbon sequestration and coal replacement at under $50 per ton.

Through the HIT Fund program, we aim to scale up this technology and demonstrate a pilot reactor capable of processing one ton of biomass into biochar per day, paving the way for further scale-up in the future.

Team Members

Arun Majumdar

Dean, Stanford Doerr School of Sustainability, Jay Precourt Professor, Professor of Mechanical Eng, of Energy Science & Eng, of Photon Science, Senior Fellow at Woods and Professor, by courtesy, of Materials Science & Eng

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