Biogas, clean energy transforming guinea pig manure
Graciela Ramirez Ramirez 2/12/2017
Project has been transforming guinea pig manure into biogas and organic fertilizer with improved properties for 23 years now.
Small in size, but big in benefits, the cuy or guinea pig, is a species from the South American Andes, where it was domesticated, and has been an important food source in Peru since pre-Inca times. This small rodent gains recognition not only for the high nutritional and medicinal properties of its meat, but also for the excellent properties of its manure in agriculture.
The use of its manure took an innovative turn 23 years ago when Agricultural Engineer Carmen Felipe-Morales Basurto, a professor at the National Agrarian University-La Molina, in Lima, carried out with her students a technological project that made possible the use of cuy manure to turn it into bio-energy, while at the same time obtaining better performance organic manure.
So Felipe-Morales, along with her husband Ulises Moreno, who is also an Agricultural Engineer, started encouraging the development of technologies that are environmentally friendly and promoting the principle of trophic recycling — the reuse of organic waste —, with the hope that this low cost energy project would also be implemented in rural areas of the country where much of the need for heat and electricity generating energy would be satisfied.
This all started when Felipe-Morales and Moreno set off in the adventure of their lives, not only as a couple, but also by putting in practice all their knowledge in agriculture, and developing ecological agriculture in a small farm located in the warm district of Pachacámac, settled on the basin of the Lurín River, south of Lima.
And this is how they made their farm, at the time just a barren plot of land, succeed by turning it into a small field of diversified crops. And in order to not be dependent on chemical supplies as fertilizers and pesticides, they developed their own technologies to produce organic fertilizers based on livestock manure, maximizing the use of all organic matter generated at their farm, specially cuy manure.
Their tireless research led them to work with Chinese model biodigestors — hermetic containers that allow for the decomposition of organic matter in anaerobic conditions, or without air, and facilitates the extraction of the resulting gas for its use as energy —, a technology that as of today only a few seem to recall that it allows to process cuy dung. The results were three highly beneficial products.
“On the one hand, the biodigestor produces biogas, which represents a savings in energy for the kitchen, but it also produces biol, a biofertilizer, for us, which is an activator for growth and outcropping — a natural hormone —, that we use to apply to the crops and is something we get every week. A muddy consistency solid is also obtained, which is the biosol, with properties that are even better than compost,” points out Felipe-Morales. The generation of biogas is made possible thanks to the Chinese model biodigestors, a technology that arrived in the country in the 70s through the Renewable Energy Program encouraged by the military government (1968-80).
Thanks to an agreement, the farm built a 10m3 capacity biodigestor to conduct research. It was built underground with bricks and mortar. On the surface can be observed three openings aligned horizontally; the organic matter, made up of cuy manure mixed with leftover partially decomposed corn stalks and husks (pre-compost) is placed in the first opening. Water and rumen, a very important component, is added to this mixture; rumen is the digestive organ of bovines which contains the anaerobic bacteria that will aid in the decomposition of the matter in the biodigestor and which is later transformed into methane gas and organic fertilizer.
In the middle opening, which is where the biogas is collected through a piping system, the hatch is tightly secured to contain the pressure of the gas produced there. The resulting liquid, called biol, is deposited in the last opening, which in turn is connected to a storage tank. This biol is very useful and beneficial for crop production.
“Every week we collect 200 liters of biol and replace it with 200 liters of pre-compost and water in order to have a continuous weekly supply of biogas and biol. This model allows for a semi-continuous loading. So, if people wish to have it just for the gas, they could load it daily. After one year of feeding it weekly, we have to empty it of the slurry that accumulates; this is another form of fertilizer,” says the agricultural engineer.
Sustainable experience and quality of life
Felipe-Morales comments that when she began to work with this technology with his students at the Agrarian University-La Molina, they discovered that cuy manure provided a larger amount of gas, compared with manure from other livestock.
“An interesting fact we found is that cuy manure has an energetic power that is more than three times that of cow manure and this is a great potential for families raising cuys. For example, a 10m3 capacity biodigestor fed with cow manure, and this is something that has been proven with research, should produce 1m3 of gas. The cuy manure produces up to 3m3 of gas on a daily basis, that is three times more. This is enough for example for four or five hours of use in the kitchen, and it can also be stored.”
Each year in March, Felipe-Morales and Moreno conduct a theoretical and practical course in which they teach the mechanisms of the biodigestor so that this experience is copied in other places.
“Cattle manure is still used in many rural areas for cooking, it is dried and burned, and this does generate a lot of toxic gasses and leads to many respiratory illnesses as well. They are contaminating and the manure that should return to the ground is not being used properly. But with a biodigestor, the population could have a clean and cheap source of energy and could have their organic fertilizer and they could sell the excess,” states Felipe-Morales.
At the moment, the couple — along with their two sons Miguel and Enrique — has transformed their knowledge into quality of life in their small 1 hectare farm, with fruit trees and different crops where they are putting all their effort on a self-sustainable system with the ecological agriculture practice and by generating their own clean energy source.
“We ask them to transform their scientific and technological knowledge into quality of life, not monetary,” Moreno says. “We, moving from the speech to fact, have transformed this farm into a paradise to live in, and instead of hiding all this, we open our doors, our minds, and our hearts, to share what we know, motivating people to promote a sustainable practice of livelihood, and we motivate the Peruvian farming families not to abandon their farms.”
The dream of Felipe-Morales and Moreno is that many more people decide to follow their example and their life philosophy, by sharing all their knowledge at their “Bioagricultura Casa Blanca” farm, now also converted into a research and training center on ecological agriculture and eco-tourism, where they show how possible the good living is by applying scientific and technological knowledge in harmony and respect with the environment. —Latinamerica Press. Compartir