How biogas from human waste will lead to energy independence

by Victoria Corless | Apr 14, 2022

"While not necessarily a topic to discuss in polite company, many experts believe that the future of sustainable energy lies in biogas generated from our own waste — and we’re not necessarily talking garbage or food scraps here.

"In recent years, research around biogas — a biofuel mixture composed mainly of carbon dioxide and methane produced from the bacterial decomposition of organic waste — has been gaining traction, and technology in this field has been advancing.

“'The cost of [photovoltaic] devices is comparatively high based on the poverty index of developing countries,' wrote a team of researchers from University of Johannesburg, South Africa, Covenant University Canaan land and Afe Babalola University in Nigeria. '60% of the world’s energy demand is required in developing countries whose current power generating capacity is unbelievably dismal.'

"Nigeria, for example, is one of the most underpowered countries in the world, with projections indicating that current supply (in the range of 12,000 MW) falls 80% below the required production based on the current population. The largest hydropower station in Nigeria has a capacity of roughly 7,876 MW, but the working capacity is only 3,000 MW, or sometimes less. Power generation is hindered by a number of compounding factors, including obsolete or inadequate equipment, corruption, poor government funding, outdated grids, and lack of advanced technologies.

"'Unfortunately, this scenario is replicated in many parts of the globe; hence, the immediate solution to the energy crisis globally is the empowering of standalone users,' wrote the team in their paper. 'The dismal performance of energy generation programs in some developing countries has exacerbated their population’s poverty rate because small and medium businesses are tied directly to energy.'

Accessible and affordable biogas

"The solution they propose centers around the production of biogas, conventional sources of which include food scraps, wastewater, and animal manure. But human waste could provide a viable, renewable source of energy, especially in regions of the world where energy supplies are unstable.

“'The shift into animal waste such as poultry droppings and cattle dung has huge prospects, but it is not sustainable in the long term as rural farmers depend on it,' said the researchers. 'The use of human excreta is the most available and sustainable due to the human population.'

"One challenge, however, is the ammonia naturally found in human waste, which inhibits the growth of methane-producing bacteria and results in impure biogas with high levels of nitrogen. Chemical and microbial pretreatments are an option, but the team wanted to develop a truly sustainable and accessible solution to meet energy demands in impoverished regions.

"The trick, according to the study published recently in Global Challenges, is to combine the waste with powdered chicken feathers. The feathers are themselves useful in generating biogas, but only when pretreated to make them amenable to anaerobic digestion. Instead of adding an additional treatment step, the scientists let the microbes found naturally in human waste do all the work for them.

"In a laboratory-scale biodigestor, the team mixed together powdered chicken feathers and human waste in a 1:5 ratio and allowed the solution to incubate, measuring the quantity and quality of biogas produced over roughly two months. Compared to controls that contained no powdered chicken feathers, the biogas produced when the feathers were co-digested with the human waste contained, at minimum, 68% less nitrogen and 73% more methane.

"'This experimentation means that there could be minimum nitrogen content with more microbes in the human excreta acting on the chicken feather as biotreatment,' said the authors. “The extensive effect of the microbes can be seen in the improved carbon dioxide and carbon monoxide content [of the biogas].'"

Read more:
https://www.advancedsciencenews.com/how-biogas-from-human-waste-will-lead-to-energy-independence/
#SolarPunkSunday #BioGas #Humanure #Sustainability #Energy

How Humanure Could Change The World (If We Don’t Turn Up Our Noses!)

"What problems does humanure solve?

Food Security & Food Prices

"2021 was not a good year for farmers buying fertilizer, with prices rocketing by 80%.

"Any hopes of relief would soon be dashed when the Ukraine war started. Russia, a key fertilizer manufacturer, restricted exports and global shipping companies veered away from the country, leading to fertilizer prices reaching an all-time high.

"These problems have helped contribute to sky-high food prices and a cost of living crisis for millions of people. Yet at the same time, on average each of us produces 145 kg a year of excrement.

"(Total annual world poop has been valued at 9.5 billion dollars, albeit as an energy source rather than as fertilizer.)

"Some countries do attempt to reclaim the nutrients while treating wastewater. Unfortunately, it’s an inefficient process, with around 90% of phosphorus lost in the process.

"Turn that excrement into compost, and we could reduce our reliance on other, sometimes unstable, countries.

"At the same time, and especially in the poorer areas of the world which are less able to afford fertilizer, humanure could help to improve the quality of poor agricultural land, improving soil structure and reducing the impact of drought.
Reduce water waste

What happens to all that food waste?

"In those of us lucky enough to live in rich countries, it is flushed down the loo with water clean and pure enough to drink out of.

"Each flush uses about 6 liters of water, and on average we go to the toilet 6-7 times a day. In total, we use about 36-42 liters of treated water to get rid of valuable organic waste.

Reduce #WaterPollution

"And what happens to that water once we have defecated? In rich countries and in poor, it can often end up in rivers and seas.

"Water pollution doesn’t just come from our waste, either. The nutrients in artificial fertilizers are often readily available to plants, but that also means it is easily washed out by rain into our rivers and water courses.

"That all means our water has huge amounts of nitrogen in it. This causes algae blooms which throw off toxins that can cause brain and liver damage.

"As the #AlgaeBloom dies, they suck the oxygen out of the water creating dead zones where nothing can live.

In contrast, many of the nutrients in compost are fixed in organic materials and are not easily washed out by rain.

"Instead, they are steadily taken up by microorganisms, some of which work in a symbiotic relationship with plants.

Reduce emissions

"A lot of blame gets put on farting cows, but human waste also releases damaging greenhouse gasses – especially in our current waste management systems.

"In fact, it’s estimated that human sanitation accounts for between 2 and 6% of methane emissions alone.

"Proper composting has the potential to vastly reduce that number. In fact, one study in Haiti found that composted human waste released 0.5% methane – compared to between 20-80% for the pit latrines and lagoon methods often used in third-world countries.

"And that’s even before we start to count the cost of shipping fertilizer around the world!

Solve sanitation problems in poor countries

"3.6 billion people still don’t have access to proper sanitation – and 494 million people still have to defecate outside. That leads to diseases almost eliminated in the West – diseases which kill over 485,000 people every single year.

"Yet the work of charities in these countries shows what can be achieved. In Haiti, for example, SOIL has provided sanitary toilets for 6000 people while turning 510 tons of excrement into agricultural-grade fertilizer.

What about human disease?

"It is, of course, natural to worry about disease. After all, we have just been talking about the diseases caused by human excrement which has not been treated.

"Science tells us, though, that if the right composting conditions are used there’s little risk to the process. As compost gets hot, #ThermophilicBacteria destroy many pathogens.

"More get killed in the maturing process, aided by the ability of worms to destroy antibiotic-resistant genes.

Challenges…

"While humanure is popular with #permaculture fans, it’s unlikely to gain mass traction in the richer parts of the world.

"Trained by convenience and ease, it’s hard to see how people will transition from flushing down poop with water in pristine toilets to collecting excrement and lumping it to a compost pile.

"Even for those who are fans, its application is likely just not viable for the many people who live in high-rise apartments and dense city blocks with little or no gardens.

"There is also the problem of our legacy sanitation systems.

"These are designed to flush all down in one with water. Replacing every pipe and toilet with a system designed to collect waste and somehow funnel it to a compost facility is likely to be hugely expensive.

And opportunities…

"A more intriguing possibility lies in the poorer parts of the world. In stark contrast to the white porcelain that greets and graces our bottoms, a huge amount of people don’t have access to good sanitation.

"With little to lose in terms of comfort and more to gain both in terms of sanitation, reduced disease and increased fertility for often poor soil, compost toilets have proved an easier ask in third-world countries.

"Scaling current efforts, though, is another thing. Perhaps when countries do come to building infrastructure in their poorer regions, systems will be designed which capture the value of our waste, rather than flush it down expensive toilets and into our rivers and seas."

https://www.compostmagazine.com/humanure/
#Humanure #SolarPunkSunday #Sustainability #WaterIsLife #Agriculture #Phosphorus