Production of biogas and biofertilizers from biodigester effluents

Abstract

One of the research and technological innovation processes which are developed within the project “Biomass
as renewable energy source for rural areas” (BIOMAS-CUBA) is related to biogas and biofertilizer production
from biodigester effluents, in agroenergy farms, where food and energy are produced, in an integrated way.
The technologies selected for constructing anaerobic biodigesters have been: fixed dome (Chinese model),
plastic tube or polyethylene with continuous flow (Taiwan type) and anaerobic lagoon covered with a high
density polyethylene geomembrane. From these technologies 69 biodigesters were constructed or repaired –
to a lesser extent-, in farms from the provinces Matanzas, Sancti Spiritus and Las Tunas, at the Experimental
Station “Indio Hatuey”, in the mountain community Magueyal (Santiago de Cuba), in a pig production facility
from Las Tunas and a livestock production farm belonging to the Ministry of Interior, in Jovellanos (Matanzas
province). These 69 biodigesters comprised a total digestion capacity of 1 665 m3 and generated productions
of 600 060 m3 of biogas, which were used for cooking food and feedstuffs, electricity generation and brick
firing; as well as 2 601 t of biofertilizers, used for improving the fertility of 1 830 ha of soils; in addition, they
allow eliminating the contamination produced by cattle and pig dung in the productive scenarios, which
generates a positive environmental impact. The installation was carried out of 52 bioproduct production plants
from biodigester effluents, enriched with native microorganisms, which are used in animal and plant health,
crop nutrition, elimination of bad odors in livestock production facilities, bioremediation of lagoons contaminated
with organic residues and in bioceramic filters.