Biomass energy generation integrated with biochar production can provide renewable energy and carbon sequestration.
At peak production California biomass facilities generated 800 MW from 66 power plants across the state. Currently, there are about 30 operational biomass plants generating about 640 MW of electricity. In 2017 biomass energy accounted for 2.82% of the states energy production. In that same year, solar and wind made up about 12% and 6% respectively. In the efforts for California to meet goals of renewable energy, it is most likely that biomass energy will continue to play only a very small portion. But it has an important role to play nonetheless.
Biomass power plants play a critical role in woody biomass management, and can produce power rain or shine. Biomass power is often located alongside industries that require heat energy, thus providing co-generation of heat and electricity (such as at sawmills). And when the biomass used for power is transformed into biochar, it provides a pathway for fixing carbon and sequestering it in soils. This is a form of Biomass Energy with Carbon Capture and Storage (BECCS), listed by the International Panel on Climate Change (IPCC) as a key technology for carbon drawdown 1.
Plants capture energy from the sun, drawing carbon dioxide from the atmosphere into their bodies to build more complex forms of carbon. Carbohydrate fibers like cellulose, hemicellulose, and lignin store carbon in plant biomass. When that plant matter is exposed to high temperatures, the energy from the sun that was used to create their bodies is rapidly released. In this way, plant biomass can be thought of as a battery of solar energy.
This is why biomass energy is often referred to as carbon neutral energy. But the alternative fate of the biomass used (was it a waste material needing a home or a living tree in a healthy forest?) and the transportation involved (is it from within the region or across an ocean?) need to be considered for this to be wholly true.
Biochar production involves the partial burning of plant material. In this partial burning, a portion of the carbon captured by the plant is immediately released. But 50% or more of the carbon can remain in its new form of biochar. Energy is also released from the plant material in this process. The release of energy can be captured and used. The purest and simplest form of energy to capture and use is heat. It is also possible to generate electricity. Most difficult of all, yet still possible, is to create transportable liquid fuels comparable to petroleum products.
There is still energy in biochar, it’s energy value is akin to charcoal or coal. In the vast majority of existing biomass-to-energy facilities the biomass used is burned all the way to ash leaving little if any carbon in the form of biochar. It is only when the value of the biochar is fully recognized as greater in soil than it is a fuel that this will change. (note: this is a key factor.)
Thankfully to all the engineers who have been hard at work, there are a few technologies that exist today which yield energy and produce high quality biochar. While still in it’s infancy in scale and recognition, some technology options are available by producers and adopted by users.
If you are interested in how you might be able to utilize biochar production technologies in your energy production projects, contact our team, we can help make it happen properly.
1 California Energy Commission. “Biomass Energy in California. California Energy Commission, State of California, www.energy.ca.gov/biomass/biomass.html. (and here) https://www.energy.ca.gov/almanac/electricity_data/total_system_power.html