A PROCESS invented thousands of years ago by Amazonian Indians could play a key role in defeating global warming, experts in Wales claim today.
The scientists from Swansea University have established a research group to develop the little-known but potentially planet-saving product Biochar.
Biochar is made when vegetable waste is burned in the absence of oxygen, a process called pyrolysis.
The substance was first discovered in the Amazon where Indians used it to fertilise the rainforest’s nutrient-poor soil, between 2,500 and 6,000 years ago. It is an extremely good fertiliser, because it contains high levels of nutrients vital for plant growth, like nitrogen, phosphate, and calcium.
It is also highly porous, which helps soil retain water, and provides a solid environment for various microbes that are beneficial for plant growth. Plus it locks carbon dioxide away, possibly for thousands of years.
Any biomass can yield biochar, including wood, as well as agricultural waste like hulls and stems.
To make the process even more environmentally friendly, pyrolysis also yields hydrocarbons, which can be made into bio-fuel.
The university’s new multidisciplinary Biochar Research Team is now playing a major part in the substance’s modern development.
The Sustainable Development Commission (SDC) has already dubbed biochar a “breakthrough technology” in tackling climate change.
Biochar Research Team member Dominic Woolf, an associate lecturer in sustainable development at Swansea University, said yesterday: “Biochar is a technology that can remove greenhouse gases from the atmosphere at the same time as providing useful energy, improving soil fertility and reducing our reliance on fossil fuel-derived fertilisers.
“Plant products that currently go to waste, such as agricultural and forestry residues, can be converted to charcoal with negligible harmful emissions, using a variety of well-established pyrolysis technologies.
“If the resulting biochar is added to soil, it not only locks up carbon for centuries to millennia, but also improves soil fertility, moisture availability and crop growth.
“The energy released during pyrolysis can be used for anything from providing heat for houses to electricity production.
“In such a system, the more energy you produce, the more you reduce atmospheric greenhouse gas concentrations. In effect, ‘plant power’ can be used to capture carbon dioxide from the atmosphere and store it in a stable solid form for years to come.
“We are investigating how biochar can be integrated sustainably into a variety of different situations around the world – from domestic and community systems suited to less-developed countries to horticultural and municipal scale systems that may be useful closer to home.”
The team is constructing a global model of the potential for reducing atmospheric levels of greenhouse gases by producing biochar sustainably.
It is also providing assistance to a recycling company that hopes to establish a pyrolysis plant in South Wales and conducting a pilot study into the physical and chemical changes that take place through time as biochar is weathered within the soil.
Jonathon Porritt, chairman of the Sustainable Development Commission, said: “Biochar could be such an important technology in our fight against climate change that we’ve included it in our list of breakthroughs for the 21st century.
“It’s great to hear of the exciting work being done in Swansea and it’s yet another example of Wales taking an important role in securing a more sustainable future.”
Alayne Street-Perrot, research professor of physical geography at Swansea and a member of the Biochar Research Team said: “One particularly attractive feature is that biochar production can be carried out in both developed and developing countries, at all scales, from individual households to large modern plants that produce significant amounts of useful energy and heat.”