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Jorge Daza's marvellous biogas machine

Wednesday, 4 December 2013 14:51 GMT

Biodigesters could provide numerous benefits to Colombian farmers and the climate, but there are many obstacles to their adoption. Photo: C. Peterson/CIAT-CCAFS

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* Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.

A Colombian farmer talks about how he installed a biodigester on his land to produce his cooking gas, but is the technology too expensive for most?

The small plot of cassava and fruit trees behind Jorge Daza’s house in the Colombian village of Macaregua in Santander looks something like the scene of a UFO crash. Strange cement tanks dot the hillside, tubes and pipes running haphazardly alongside them – the debris of the wreck. A great black bottle-shaped cylinder lies buried up to its neck in the orange clay soil – the mother ship.

It may not be extraterrestrial, but it is still unusual: a fully functioning biodigester that converts livestock manure into gas for Jorge’s kitchen.

One of the main culprits for agriculture’s contribution to climate change is livestock production, in large part due to greenhouse gases released from manure and animal digestive tracts. From 2005 to 2030, emissions of methane and nitrous oxide from manure management alone are projected to rise by 17 percent.

What would happen if we could prevent the release of these gases and at the same time use them for something practical?

Ongoing research from the CGIAR Research Programme on Climate Change, Agriculture and Food Security (CCAFS) is taking a look at what farmers in Colombia can do - and are doing - to adapt to the effects of climate change while being mindful of mitigation.

For those on the front lines, climate-smart technologies and practices such as biodigesters can boost food security and resilience to climate change impacts.

MITIGATION BY DESIGN

Anaerobic methane digesters are not a new idea, but models as impressive as Jorge Daza’s are usually reserved for industrial-sized operations.

“The design comes from a business called FEDETABACO, which is the company that buys our tobacco and also sets aside some money for these types of projects,” says Jorge. “I saw the design and made modifications to it for some parts that I knew were not working.”

FEDETABACO agreed to give the improved model a try, supplying the materials (over 7 million pesos’ or more than $3,500 worth) while Jorge provided the time, location and manpower.

Obviously proud of his marvellous machine, Jorge relishes explaining the construction process. A small canal carries the manure from his three pigs downhill to a collecting tank. From there it passes to the fermenting tank - the mother ship from our UFO crash.

“I built this myself out of concrete blocks,” he says, gesturing to the fermenting tank. “This is where the methane gas is produced,” he continues, giving the tank a friendly knock. “We’ve sealed everything perfectly so that nothing cracks and none of the gas escapes.”

An insignificant-looking metal pipe carries the precious methane gas straight to the camp stove in Jorge’s kitchen. The spent manure, now free of methane, is propelled by pressure into another tank to be used later as a rich fertiliser.

Jorge’s design goes far beyond the structure itself – the entire investment has been thought out from beginning to end.

“I want to buy a few more pigs – maybe 10 in total – to keep the tank full all the time,” he says. “The residue manure I’m trying out as fertiliser, and if it works I want to start an orchard. I could fit in maybe 50 avocado trees here, which would be more than enough to sustain my family!”

FINANCIAL REALITIES

With such an entrepreneurial spirit, Jorge’s vision seems remarkably feasible. But when asked whether such a scheme could be extended so that more farmers in Macaregua could take advantage of its benefits, he pauses.

“It’s an enormous investment for people out here,” Jorge admits. “It’s safe to say that nobody in this village has 7 million pesos to put into such a project. Plus you have to think about the cost of acquiring the pigs and feeding them. It won’t happen without support from the outside, like happed for me.”

 What’s more, Jorge remarks, “the thing is complicated to build. You have to have someone who knows construction. This took me and two other guys three weeks to do - a long time for a couple of cement tanks.”

Jorge has the gift of foresight and the knowledge of an experienced contractor. Other farmers in Macaregua with similar resources are few to none. However, there are biodigester projects in nearby villages that have been successful too. “We’ll have to see if the support shows up for Macaregua,” Jorge concludes.

If he is an exception, just how feasible are biodigesters as a climate-smart tool for the average Colombian farmer?

For starters, many small-scale farmers lack the financial capital to invest in one. Acquiring and maintaining livestock can be a big change and an additional cost for farmers who don’t already raise them. Poorly constructed biodigesters often break or stop working, with little follow-up from the implementing organisations.

For all that, their benefits are considerable: improved human health from reduced reliance on smoky wood-burning stoves; lower costs for fuel and fertiliser inputs; and additional sources of income from raising livestock.

They are also a win for the climate as well, in terms of lower emissions from manure and fertiliser use, and reduced deforestation from wood fuel consumption. Latin America is a world leader in the adoption of biodigester technologies, although most countries in the region lag well behind Brazil. Nevertheless, knowledge and practical experience on the matter exist here in abundance.

One option for overcoming the hurdles to biodigester adoption is leadership by farmer-driven organisations, which can provide access to the technical and financial requirements and coordinate with both the public and private sector to bring needed services to their areas.

Low-cost options like biodigesters made with polyurethane bags are simpler to build and can be used by small farmers with few livestock, as long as demand from farmers themselves is forthcoming.

A biodigester would be an out-of-this-world improvement on most farmers’ current fuel sources, but it is earthly partnerships and organisations that are needed to make them a reality.

Caity Peterson is a visiting researcher and science writer based at the Center for International Tropical Agriculture (CIAT) in Cali, Colombia, working on CCAFS Theme 1: Adaptation to Progressive Climate Change.

A Spanish-language version of this article was published in the Colombian newspaper El Espectador in October: La maravillosa maquina de Jorge Daza

This blog is part of a series on Colombia – the second one will be out next week.

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