Tag Archives: biochar

Creating a carbon vacuum: turn MSW into charcoal and bury it

During a recent round-table session I attended with British scientist and Gaia author James Lovelock, it was easy to walk away feeling helpless about the climate problems humanity faces. But when pressed, Lovelock said he does believe there’s potential in “biochar” — that is, converting some of the world’s biomass (e.g. forest slash, agricultural residues, fast-growing grasses grown on depleted soils, farmed algae) into charcoal and sequestering the black mass in soil or under the ocean. This is done through a process called pyrolysis, which when creating the charcoal locks in about 60 per cent of the biomass’s carbon. Charcoal stays inert and chemically stable for hundreds of years. Best to turn some of the world’s biomass into charcoal instead of letting the biomass rot and release methane into the atmosphere. At least that’s the thinking.

In the end, it’s the rough equivalent of making coal, but doing it in a few hours instead of a million or so years. It’s considered better — and likely cheaper — than the capture and sequestering of fossil-fuel CO2 emissions because it doesn’t just avoid the release of emissions; so-called charcoal sequestration can lead to the extraction of CO2 from the atmosphere. This makes it carbon negative. Turning some of the biomass into charcoal prevents new emissions, but the new generation of biomass that grows also absorbs CO2 from the atmosphere. Over time, the cycle of charring biomass and growing new biomass can act like a big global carbon vacuum.

The trick is doing it on a large enough scale to matter. EnCana researcher Subodh Gupta, a big believer in charcoal sequestration, recently argued at the Canadian International Petroleum Conference in Calgary that the best way to demonstrate that the approach works is to start with the organics and even some plastics collected from municipal solid waste. It solves many problems. Continue reading Creating a carbon vacuum: turn MSW into charcoal and bury it

Biochar gets some attention at Poznan as a measurable way of sequestering carbon

What’s a promising way of removing carbon from the atmosphere? Scientists attending climate talks in Poznan, Poland, are trying to sell the idea of biochar, a type of charcoal produced when biomass like agricultural and forest residue is “baked” in the absense of oxygen. This process, called pyrolysis, also produces syngas and bio-oil that can be used as a renewable fuel. But it’s the char or “black carbon” that’s capturing scientists’ imagination. The pyrolysis process locks carbon into the char, which remains stable for hundreds, potentially thousands of years. Continue reading Biochar gets some attention at Poznan as a measurable way of sequestering carbon