Pork Industry Aims to Cut Methane

Unison Solutions is proud to supply the pork industry with biogas upgrading systems and components to help them meet their methane reduction goals.

When the workday is over for Wen Murphy, more often than not, he continues to think about his job. A fourth-generation farmer, he constantly keeps top of mind the staff, the animals, the productivity, the supplies, the cash flow and myriad other details that must be attended to. In short, the sustainability of being a hog farmer. But above all, he is preoccupied with what he will leave for his family members and others who will someday walk the path of those who went before him.

According to Frank Mitloehner, that’s not uncommon for people who work the land. An animal agriculture expert and air quality specialist with University of California, Davis, he spends his days teaching, researching and partnering with agriculturalists to help them improve their environmental footprints. It’s not only concern for the environment that spurs them on – although that certainly is critical right now – it’s also about ensuring the viability of their operations.

Based in North Carolina, Murphy is a principal in Murphy Family Ventures, a large and diversified agricultural enterprise and one of the biggest swine producers in the United States. These days, in addition to a wide array of other challenges facing farmers, there’s a desire, some pressure and even legislation aimed at cutting greenhouse gas emissions. People like Murphy and Stewart Leeth, chief sustainability officer for Smithfield – the world’s largest pork producer and America’s No. 1 pork supplier – are finding ways to rise to the occasion.

Where global warming and animal agriculture are concerned, the issue most often is methane, the second-most plentiful greenhouse gas. Methane is a problem because of its short-term warming potential – it traps solar radiation in the atmosphere at a rate roughly 25 times that of carbon dioxide over 100 years, but only for a decade or so after it’s emitted. Ten years in, it’s broken down; its high warming potential is destroyed.

“Methane is a potent greenhouse gas. But methane is an interesting gas because it’s not just produced – by let’s say animal manure – but it’s also naturally destroyed … and it has a short lifespan. And that really is special because what it means is that animal agriculture, which has the main greenhouse gas as methane, can reduce that gas and by doing so, reduce the warming,” he explains.

Yet, pig farms shouldn’t get overlooked. While it’s true pigs’ enteric emissions are relatively small, their manure, when stored in traditional open lagoons, combines with methane-producing microbes to become a significant source of what Mitloehner often refers to as a “fast and furious” greenhouse gas.

Storing manure in sealed systems, called anaerobic digesters, has emerged as one of the best approaches to taking a bite out of farms’ methane emissions, with the EPA naming them the top tool in our arsenal. In addition to putting a literal lid on methane emissions, these closed systems produce biogas, a fuel that can be piped out to replace petroleum-based sources of energy, the primary contributors to global warming and climate change.

“We’ve been looking at ways to get energy out of the manure for many, many years. The old style of dealing with that was really trying to capture the manure biogases produced under the digesters and burning it on the farm through microturbine,” he says. “What’s really neat about these [newer] projects is it’s … a different model. We’re capturing the biogas, pooling it together with other farms and selling it really as a product. And the value of that product is many, many times more valuable than a commodity fossil gas, and it’s a real opportunity for farmers in North Carolina,” says Leeth.

Not only do the digesters offer a double environmental win – that is, reducing methane emissions while producing a climate-friendly fuel – selling off the biogas is a new revenue stream for farmers; one that can help fund the pricey digesters.

“Farmers who say, ‘We want to be part of a solution here, and we do want to use technologies, are financially supported and there’s actually now a carbon-credit system that helps farmers financially benefit from reducing emissions by first and foremost using the technology that we are talking about here – anaerobic digesters,” he says. The resounding message seems to be: “Work with – and not against – farmers if you want to achieve good environmental outcomes.”

“We want to make sure that there is a future in this industry and that we can continue farming,” Murphy says.

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