Carbon negative options have been studied for years. However, today biomass plantations and biochar can easily be a part of any project aiming to mitigate climate change. 

In California, a new UC Berkeley study shows that if biomass electricity production is combined with carbon capture and sequestration in the western United States, by 2050 power generators could reduce emissions up to 145 percent from 1990 levels, even while retaining gas- or coal-burning plants. Such reductions can occur with as little as 7 percent of the power coming from “Bioenergy combined with Carbon Capture & Sequestration”, also known as BECCS.

BECCS, may be one of the few cost-effective carbon-negative opportunities available to mitigate the worst effects of anthropogenic climate change, said energy expert Daniel Kammen, who directed the research. This strategy will be particularly important should climate change be worse than anticipated, or emissions reductions in other portions of the economy prove particularly difficult to achieve.

The carbon reduction might even offset the emissions from fossil fuel used in transportation, said study leader Daniel Sanchez, a graduate student in UC Berkeley’s Energy and Resources Group.

Sustainable biomass can play a transformative role in the transition to a decarbonized economy, with potential applications in electricity, heat, chemicals and transportation fuels.

Deploying bioenergy with carbon capture and sequestration (BECCS) results in a net reduction in atmospheric carbon. BECCS may be one of the few cost-effective carbon-negative opportunities available should anthropogenic climate change be worse than anticipated or emissions reductions in other sectors prove particularly difficult.

Previous work, primarily using integrated assessment models, has identified the critical role of BECCS in long-term (pre- or post-2100 time frames) climate change mitigation, but has not investigated the role of BECCS in power systems in detail, or in aggressive time frames, even though commercial-scale facilities are starting to be deployed in the transportation sector.

How it works

Generating electricity from biomass, such as urban waste and sustainably-sourced forest and crop residues, is carbon-neutral: it produces as much carbon as the plants suck out of the atmosphere.

Biochar test plot after two passes of biochar spreading. Photo: Dynamotive Energy Systems.

In this case, the emissions generated from the system are aggregated at a single point, the power plant — as opposed to being released at thousands of points as in th case of biofuels used in transportation. This allows the emissions to be captured — and in the case of Carbon Capture and Sequestration, stored. In this way, carbon is essentially brought from the forest, crop or residue source and used to generate energy, but the resulting emission is captured and stored. Then, the next generation of crop or forest would pull its CO2 from atmospheric carbon, accumulating stored carbon with each cycle.

Biomass crops taking 50,000 kilos of dry matter per hectare every year. Some for renewable energy, some will finish in soil. Using biochar, we add much more carbon ad biofertilizer and we don’t spend so much money in urea or other fossil sourced nitrogen fertilizers which are 70% of all our biomass delivered product’s footprint.

Sanchez noted that burning biomass as part of BECCS may have a greater impact on greenhouse gas emissions than using these same feedstocks for biofuels, solely because of the possibility of carbon capture.

Here below we attach a good examples of what we are talking about (Source: biochar.com):

The recent study published explored the economic and deployment implications for BECCS in the electricity system of western North America under aggressive (pre-2050) time frames and carbon emissions limitations, with rich technology representation and physical constraints.

Authors showed that BECCS, combined with aggressive renewable deployment and fossil-fuel emission reductions, can enable a carbon-negative power system in western North America by 2050 with up to 145% emissions reduction from 1990 levels.

Biochar applied to dedicated biomass plantations can improve even more the normal carbon sequestration of biomass and biofuels produced. This means, we can produce electricity, heat, gases or fuels and sequester carbon at the same time we improve soil fertility for food and we reforest degraded or previously deforested lands.

In most scenarios, the offsets produced by BECCS are found to be more valuable to the power system than the electricity it provides. Advanced biomass power generation employs similar system design to advanced coal technology, enabling a transition strategy to low-carbon energy.

The full article is available here.

Read full article on biochar in The Economist “Biochar could enrich soils and cut greenhouse gases as well“

See more on bioenergy crops and carbon negative solutions here.