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[Michaelangelica]

Who is going to tell them that this is not 'NEW' and we have been flogging the idea for ages?
erich?
Bioenergy pact between Europe and Africa

Back to black: hydrothermal carbonisation of biomass to clean up CO2 emissions from the past

Gradually, a new, 'low-tech' geosequestration option is attracting the attention of more and more scientists. It is based on converting biomass into an inert form of bio-coal or charcoal, that can be stored in soils. Earlier we referred to carbon-negative energy systems that rely on gasification and biochar sequestration: biomass is gasified which results in a carbon monoxide and hydrogen rich gas that can be used for energy or transformed into ultra-clean synthetic biofuels via the Fischer-Tropsch process, whereas a fraction becomes bio-char that can be stored in soils (using a technique known as 'terra preta'). Similar techniques can be build around pyrolysis processes (earlier post). In such systems, soil fertility would be gradually enhanced, 'historic' CO2 would be sequestered and clean biofuels could be used to power our societies.

Only biomass can be used for the creation of such carbon-negative energy systems that clean up our emissions from the past. Other renewables are carbon-neutral at best, meaning they can only reduce future CO2 emissions - something many scientists think is not enough to avert dangerous climate change.

Maria-Magdalena Titirici, Arne Thomas and Markus Antonietti of the Department of Colloid Chemistry at the Max Planck Institute of Colloids and Interfaces, now describe a new, highly efficient though 'low-tech' way to use biomass as a tool to clean up past emissions. Their research appears in an open access article in the New Journal of Chemistry, in which they suggest creating "turbo-rainforests" based on fast-growing energy crops that are grown, turned into bio-coal via a process known as hydrothermal carbonization (HTC), and then stored into 'carbon landfills', while deriving energy from the process. The technique can be practised on an ultra-large scale, and can thus be described as a geo-engineering option - one that is actually technically and economically feasible.

Importantly, in contrast to other biomass carbonisation techniques that require dry biomass, the hydrothermal carbonisation process is a highly efficient 'wet' process that avoids complicated drying schemes and costly isolation procedures. The resulting carbonaceous materials also open a new field of chemistry, full of novel possibilities and challenges that may lead to the development of new (nano)materials: