The story of biochar is inevitably a story about biomass and how people manage biomass resources. In California, decades of forest management practices that included over-planting and fire suppression have led to forest ecosystems that are overloaded with woody biomass. Drought and climate change have compounded the problems, leading to large areas of unhealthy forest systems that are prone to catastrophic fires.
Across the state forestry efforts are mobilizing to reduce fuel-loads in high fire risk areas, limiting the excessive accumulation of biomass and promoting sustainable forestry practices. Biochar can be a powerful tool; turning a woody biomass problem into an opportunity to build healthy soils, generate renewable energy, and improve the health of our forest ecosystems through effective biomass management.
California has a woody biomass problem. Forests cover ~33,000,000 acres of land in California managed by federal, state, and privately-held forestry organizations and individuals (1). Harvesting timber plays a major role in California biomass resource management generating ~8,000,000 tons of forestry slash and ~6,200,000 tons of mill residues every year (2). “Forestry slashâ€ is biomass left in forests after selective harvesting has removed branches and tree tops from usable timber logs for transport to milling facilities. “Mill residuesâ€ are generated at these milling facilities while processing timber logs into dimensional lumber. These biomass resources are often viewed as a waste or byproduct of the timber industry and it is common practice for residues and slash to be gathered into piles and burned to avoid additional fuel-loads increasing the risk of wildfire.
In total, California generates ~26,800,000 tons of forestry biomass “waste” each year, which includes forest thinnings and shrub-land in addition to forestry slash and mill residues (2). If biochar was solely produced from these abundant biomass resources, at 20% conversion efficiency (i.e. 5 tons biomass becomes 1 ton biochar), California forests could generate over 5,000,000 tons of biochar and generate more than 10,000 MW of renewable energy annually using only the excess woody biomass, i.e. without clear-cutting or over-harvesting in the process.
Looking beyond forestry residues, the total biomass resource base in California is estimated to be over 50 million tons (2). If developed, a biomass market with this capacity would make a significant impact on renewable energy generation and biomass resource management state-wide.
In promoting the production and application of biochar, it is important that we must consider the source and alternative fate of the biomass resources we use to produce biochar and the impact of increased biochar production. When biochar is produced, a portion of the carbon in the biomass is immediately released into the atmosphere. When burned clean, most of that carbon released enters the atmosphere as CO2. The carbon that is not released immediately becomes fixed into a new state that can resist decay for hundreds of years, and that part is pretty cool. Woody biomass that is decomposed on the forest floor will release nearly all of it’s carbon back into the atmosphere in one hundred years. So, in the one hundred year timeline, biochar production can help put a lot of carbon back into soil. But when we move that timeline into a ten year timeframe, it can change the outcome for some situations. We may only have about ten years before the climate moves beyond control, so this is a really important question. In what situations does biochar production reduce greenhouse gas emissions within a ten year timeframe? Where the alternative fate is burning in an open pile, catastrophic wildfire, or complete combustion, then clean burning production of biochar and energy is a clear winner – and at our production sites in California, that is what we do, that is the niche where our biochar production exists. The biochar produced at our CA facilities is from biomass sourced almost exclusively from designated high fire hazard areas, there is extensive emissions controls with constant monitoring, and the energy generated adds to Californias renewable energy profile. At Pacific Biochar Benefit Corporation we are committed to doing our part to improve the ecosystems that we all depend upon.
1 Christensen, Glenn A.; Waddell, Karen L.; Stanton, Sharon M.; Kuegler, Olaf, tech. eds. 2015. California’s forest resources: Forest Inventory and Analysis, 2001â€“2010. Gen. Tech. Rep. PNW-GTR-913. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 293 p.
2 Williams, Robert B., Jenkins, B.M, Kaffka, Steve (California Biomass Collaborative Department of Biological and Agricultural Engineering). 2008. An Assessment of Biomass Resources in California, 2007. California Energy Commission. Publication Number: CECâ€2013â€500â€052.
Biochar from woody biomass