Industry slow to sell biocharcoal climate merits

LONDON (Reuters) - Industry has struggled to commercialize a charcoal technology which some say could reverse the effect of manmade carbon emissions, as countries fail to implement incentives and technical problems nag.

Biochar is a form of charcoal made from heating solid waste such as rice husks and farm manure, and as a stable substance when put in the soil may lock up the greenhouse gas carbon dioxide (CO2) for hundreds of years.

Supporters say it could dramatically cut carbon emissions, improve soil fertility, boost energy security and combat waste.

But only a handful of companies have sold biochar-making units so far, while firms turn to marketing biochar's secondary benefits as a lightweight fuel or fertilizer.

"To make biochar work you need a credit for carbon storage," said Simon Shackley, a researcher at Britain's Edinburgh University, which has won funding to test its potential.

Biochar is a stable form of carbon, and because it is derived from trees and other plants which originally sucked the carbon dioxide (CO2) from the air, plowing it into soil could reverse emissions from burning fossil fuels.

The International Energy Agency (IEA) said in 2008 that global greenhouse gas emissions were so out of control that avoiding more dangerous levels of climate change depended on driving so-called negative emissions later this century.

An Edinburgh University farm trial had shown yield benefits from applying biochar to the soil, Shackley said, but additional government incentives to reward its climate benefits were needed to make it economic. Some studies have also suggested it could help retain soil moisture.

Slow rollout may reflect wider difficulties in generating distributed energy from waste such as woodchips and manure, which are more expensive to transport than oil and natural gas.

"I'm still fully convinced we need to explore it to the fullest," said Cornell University's Johannes Lehmann, a leading advocate. "We don't dare make predictions of what's possible, we're just probing the technical potential."

MANURE

One possible way to reward farms for turning their manure into biochar may be a carbon offset scheme where polluters pay for projects which cut carbon emissions. A draft U.S. climate bill had proposed just that for biochar, but is stalled in the Senate.

A lack of standards is also a problem.

"It's still a bit of the wild west," said Debbie Reed, executive director of the lobby group the International Biochar Initiative, which wants to compile guidance for the production process and materials, to aid testing and certification.

"We're not ready for a large-scale roll-out. Right now anybody who's creating a product that looks like ash or charcoal can call it biochar," she said. "That's one of the things in the commercial space that will hold up the entire industry."

Making biochar involves heating organic matter without oxygen, called pyrolysis. That process also produces a high-energy gas which can be burned to generate electricity.

Slow pyrolysis creates various acids, tars and other chemicals which suppliers must show they can extract and use or dispose of, said Aston University's Tony Bridgwater.

"The question of what farmers will do with condensed tars from 'charvestors' needs more work," said Timothy Langley at New Zealand-based Carbonscape, referring to their own microwave-based biochar units. "We acknowledge the problem and intend to solve it in the not too distant future."

Texas-based MaxWest Environmental Systems is one of a very few companies worldwide which has sold units to manufacture biochar. A major motive of the buyers was to sanitize poultry manure, saving on tipping fees, and turn this into a saleable fertilizer, said the company's Robert Erwin.

Among other companies with plans to sell pyrolysis units, whether for energy or biochar, is JFBioEnergy Inc. The company's John Flottvik said it can turn dead trees destroyed by the pine beetle in Canada into a useful resource.

(Reporting by Gerard Wynn, Editing by Keiron Henderson)