Turning turds and trees into beautiful biochar

Alf has just had an encounter of the turd kind with biochar and found it isn’t a form of Chinese cuisine.

Fair enough, had he been paying attention to climate change and what’s being done to beat it, he probably would be well acquainted with biochar and how it can do good things for effluent.

But he hadn’t and he isn’t.

Not until now, when he happened to be browsing through the BBC’s news of the day and found himself being asked whether the hype about biochar is justified.

Because the hype had bypassed him, or somehow he had evaded it, he didn’t know. So he read further and learned:

Green guru James Lovelock claims that the only hope of mitigating catastrophic climate change is through biochar – biomass “cooked” by pyrolysis.

It produces gas for energy generation, and charcoal – a stable form of carbon.

The charcoal is then buried in the ground, making the process “carbon negative”.

Researchers say biochar can also improve farm productivity and cut demand for carbon-intensive fertilisers.

Say no more. Anything that can improve farm productivity, cut demand for carbon-intensive fertilisers and mitigate catastrophic climate change has gotta be good for the good people who farm around Eketahuna. Doesn’ it?

As Alf further learned, during his online voyage of discovery, work is being done on biochar in this country. In Marlborough. But we’ll come to that…

The BBC item focussed on Bingen, Germany, and the conversion of effluent into glittering black granules.

In a flash of eco-alchemy, they are turning sewage into charcoal.

The charcoal is then buried to lock the carbon into the ground and prevent it entering the atmosphere.

Proponents of the technology say it is so effective at storing carbon that it should be included in the next global climate agreement.

Burying the biochar can also improve soil fertility, say experts.

Field trials are about to begin at Rothamsted, south-east England, to assess the benefits to soil structure and water retention.

Experiments in Australia, US and Germany are showing great results, too, apparently, especially on otherwise poor soils where the honeycomb granules of biochar act as a reservoir for moisture and fertilisers.

A growing worldwide movement is now bringing together the soil scientists fascinated by the benefits of biochar, which was first discovered in Pre-Columbian Amazonia, and the engineers devising new ways of making the char.

They are being backed by activists who are concerned about climate change.

One big problem for Alf is getting to grips (as they are doing at the Bingen biochar plant) with “pyrolysis equipment” to overcome the problem of ash from sewage waste choking conventional boilers. His eyes glaze, on hearing words like that, and he is tempted to move on to his favourite on-line comics.

But pyrolysis seems to be a force for good, rather than evil.

Normally, sewage treatment is a significant source of greenhouse gases. The waste is usually incinerated (with more emissions) and the resulting ash is used in the building industry.

At Bingen, 10% of the sewage stream is being diverted to the prototype pyrolysis plant, where it is heated with minimum oxygen.

Carbon monoxide and methane are driven off and burned to heat the pyrolysis process.

The process is said to radically cut the fuel costs and carbon emissions needed to treat the sewage, and an estimated 60% of the carbon from the sewage is locked up in the char.

The buried carbon will be kept from entering the atmosphere for a projected 1,000 years or more.

And as the sewage was originally created from plants, which removed CO2 from the atmosphere, the total process is described as carbon negative.

The pyrolyser at Bingen – like others being developed elsewhere – can transform any carbon-based substance, including some plastics, the BBC says.

That means pyrolysis can get energy from agricultural waste, food waste and biomass.

But the catch is that it creates less energy than burning biomass in a conventional way.

The BBC then drew attention to the substantial barriers to the progress of biochar.

Perfecting and disseminating the technology at an affordable price will be an issue.

Moreover, current financial systems reward energy production from biomass and waste – not carbon storage. Biochar would need clear global incentives.

One key to its progress will be ongoing research into the soil benefits.

The porous biochar attracts worms, apparently. It also captures nutrients that would otherwise run off the land, which reduces the need for carbon-intensive fertilisers.

Alf was somewhat dismayed to find research on biochar began back in 1947 (which means he should have heard about it long before now). But it was forgotten until the 1980s, and only recently– it seems – is there a lot of excitement about what it might achieve.

Wikipedia gave Alf a helping hand. It says

Biochar is a way for carbon to be drawn from the atmosphere and is a solution to reducing the global impact of farming (and in reducing the impact from all agricultural waste). Since biochar can sequester carbon in the soil for hundreds to thousands of years[3], it has received considerable interest as a potential tool to slow global warming.

Oh, and things are bubbling on the biochar front in this country.

About a year back, Rural Delivery pointed out that

New Zealand produces millions of tones of wood waste, which could be converted into biochar, or finely ground charcoal, and incorporated in the soil like lime for a range of benefits. Carbonscape of Picton is developing one of the first portable pyrolysis units for producing charcoal.

The company was founded by Nick Gerritsen, former Christchurch mayor Vicky Buck, olive industry pioneer Hamish Macfarlane, and others.

It had recently hired its first manager, who is overseeing the building of the pilot plant, with chemistry contracted elsewhere.

Six months later, the Herald reported:

A New Zealand company which says it has patented world-first industrial technology to microwave forest waste is planning to offer charcoal to farmers and horticulturists who want to boost the quality of their soils.

The technology can capture significant amounts of carbon dioxide from the atmosphere and hold it for 10,000 years by putting the charcoal into topsoils, and at the same time improve plant growth.

The company, Carbonscape, has begun initial batch scale production of the “biochar” at its Marlborough plant.

Forestry Minister Jim Anderton officially opened the plant today and said the technology “appears to be a huge breakthrough in charcoal development”.

Much more recently, Carbonscape announced that Tim Flannery, Australian of the Year (2007), author of The Weather Makers and international campaigner on climate change, is joining the team as a board director.

“I’m delighted to be joining Carbonscape” says Tim,

“The technology developed by Carbonscape is exciting and promises to make a dent in carbon dioxide levels. We have to get greenhouse gas levels down and fast. Carbonscape offers the possibility of doing that.”

The company statement quoted director Professor Chris Turney as saying Flannery brings enormous expertise in fighting climate change to Carbonscape.

“Climate is changing and we need to do something fast. Tim will help us identify the best way Carbonscape’s technology can be most effectively used internationally. We’re over the Moon he has agreed to come on board.”

MAF has been on the case, too. It is setting up an information network to share knowledge on the application of biochar to New Zealand soil as an opportunity to reduce greenhouse gas emissions.

The objectives of the project are to:

1. Transfer knowledge on NZ biochar research and technology developments and relevant international research to NZ stakeholders with a focus on the application of biochar to reduce GHG emissions.

2. Provide a mechanism to discuss biochar issues and stakeholder needs with regard to the operational application of biochar.

Mind you, this work could fall under the Government chopper. It was instigated when the Government aimed to make New Zealand carbon neutral by 2020.

We aren’t in such a rush now, eh?

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