Biogas manufacturing has been not unusual in different EU international locations for years (in keeping with knowledge from the Ecu Biogas Affiliation, EBA). Through the tip of 2020 there have been virtually 19,000 biogas vegetation within the Ecu Union, maximum of them in Germany, with greater than 11,000 vegetation, adopted through Italy (greater than 1,600) and France (greater than 700), whilst Spain handiest had about 300.
Certainly one of which is the co-digestion biogas manufacturing plant discovered at the Capdevila Torrent Ramaders Farm positioned in Alcarràs (Lleida, Spain), run through Josep Capdevila, who lets say was once a visionary in our nation since, on the finish of 2015, he already opted to valorize the manure produced on his 4,000-sow farm and introduced the challenge.
Biogas manufacturing plant by means of co-digestion.
How does a biogas plant paintings?
The farm produces about 28,000 m3 of slurry in line with 12 months. The biogas era plant has a coated reception lagoon with a capability of 180,000 liters. The slurry is channeled from the barns to the lagoon thru pipes. Due to a homogenizing agitator with other positions, the contemporary slurry is blended with the co-substrate, on this case, chopped corn grown at the farm’s 11 hectares.
Each and every two days, 800 to 1000 kg of corn silage is blended with 100 m3 of slurry. The agitator runs for roughly 10-15 min/day. After blending, a pump pumps 60 m3 of recent subject matter day by day to the highest of the digester, the place the anaerobic procedure that may produce biogas will happen.
Left: Pre-lagoon blending of slurry with the co-substrate, on this case corn silage. Proper: corn silo.
This digester, 23 m in diameter and six m top, has a capability of two,400,000 l and has two agitators. It’s crammed to roughly 5.40 m as a security measure. There may be an inner protection internet in order that the tarp by no means falls within the tournament of digester failure or when restore paintings is being executed at the digester.
Biogas manufacturing stays relatively strong right through the 12 months since this sort of biodigester has an inside heating circuit, which is fed through its personal power manufacturing, and which permits the inner temperature to be maintained in order that the micro organism can paintings correctly (the optimal temperature in those instances is round 37ºC).
Some of the issues of this sort of procedure is the manufacturing of hydrogen sulfide, which is very corrosive. The device has an air compressor that serves two functions: to insufflate oxygen to lend a hand precipitate the hydrogen sulfide and to stay a tube positioned within the higher perimeter of the digester inflated that acts as a pressurized belt conserving the tarp.
However, we should no longer put out of your mind the digestate, a product with a top fertilizing capability. It flows down a pipe through gravity and is saved in a lagoon with a capability of two million liters.
Digestate garage lagoon.
Monetary advantages
From the biogas produced, which is 62 to 64% natural, the plant produces electric and thermal power. The co-generation engine has already labored 67,000 h and because its start-up, 3,843,000 kW had been produced. The co-digester produces sufficient fuel to offer 100% of the farm’s electrical energy wishes, with kW left over to be despatched to the ability grid. The fuel boiler, plus the warmth recovered from the co-generator, provides 80% of the farm’s thermal wishes (to warmth the radiant water circuit within the barns, in addition to to handle the inner temperature of the co-digester), whilst the rest 20% of the desires are generated from a biomass boiler.
Ultimate 12 months was once the absolute best manufacturing 12 months to this point, with a complete of 514,000 kW, with engines operating a median of about 23.6 h in line with day (engine upkeep should be taken into consideration).
View of the co-generation apparatus and boiler and sizzling water distribution house.
The funding was once €480,000 and paid for itself in 6.5 years. 8 years in the past, earlier than beginning the challenge, annual electrical energy and heating prices had been round €98,000/12 months. With present electrical energy and fuel costs, some great benefits of biogas manufacturing are top.
The landlord of the farm, Josep Maria Capdevila, controls the environment within the digester.
As for the digestate, along with its use at the farm itself, it’s bought as fertilizer to other farmers, offering any other supply of source of revenue. The landlord says that during fresh months, because of the rise in the cost of chemical fertilizers, the call for for digestate has greater.
Environmental advantages
Anaerobic digestion of slurry and the resultant manufacturing of biogas has a favorable environmental affect because it reduces greenhouse fuel emissions, produces renewable power, power self-sufficiency, stabilized and blank biofertilizer, and decreases odors.