The Use of Biodigesters in the Treatment of Swine Manure …
119
Fig. 9 Frontal and superior view of the concrete biodigester. Source Pictures taken by the authors
of minimum generation operation even if the gas network becomes unavailable at
some point.
13.4 Concrete Biodigester
The concrete biodigester was also designed as an alternative way of building biodigesters, adapted to the Brazilian rural context. However, it was verified, still in the
construction phase, that this project needs to be reassessed in the future. Its assembly
complexity is superior to the other biodigesters of the Biogas Project, especially
with regard to the assembly of its box and hardware (steps prior to concreting). Its
rounded shape and the necessary wall thickness made its assembly more difficult
than planned, once the sliding shape technique could not be used (Fig. 9).
The difficulties identified in the assembly of the concrete biodigester demonstrate
that its reproduction is not a trivial proposal. Especially if considering that the target
audience are small and medium-sized producers, who are generally located in regions
further from large centers and with limited resources. In such a manner that they
would need to improve their production process in order to adapt to the increasingly
complex and challenging Brazilian environmental legislation. As well as having to
meet the growing consumers demands regarding environmental preservation. This
is associated with what they willing to consume and pay a premium price when
perceiving the producer alignment with their values [44].
13.5 Canadian-Type Biodigester or Covered Lagoon
The Canadian biodigester is a horizontal biodigester that has a rectangular base and
a gasometer made of a flexible PVC blanket that surrounds the base. It has greater
width than depth, resulting in a greater area of exposure to the sun, which contributes
to the increase in biogas production (as the heat retention provides greater bacterial
activity). This model is also known as covered lagoon, navy or balloon. It has low
cost of implementation, easy maintenance and cleaning, with the disadvantage of
119
Fig. 9 Frontal and superior view of the concrete biodigester. Source Pictures taken by the authors
of minimum generation operation even if the gas network becomes unavailable at
some point.
13.4 Concrete Biodigester
The concrete biodigester was also designed as an alternative way of building biodigesters, adapted to the Brazilian rural context. However, it was verified, still in the
construction phase, that this project needs to be reassessed in the future. Its assembly
complexity is superior to the other biodigesters of the Biogas Project, especially
with regard to the assembly of its box and hardware (steps prior to concreting). Its
rounded shape and the necessary wall thickness made its assembly more difficult
than planned, once the sliding shape technique could not be used (Fig. 9).
The difficulties identified in the assembly of the concrete biodigester demonstrate
that its reproduction is not a trivial proposal. Especially if considering that the target
audience are small and medium-sized producers, who are generally located in regions
further from large centers and with limited resources. In such a manner that they
would need to improve their production process in order to adapt to the increasingly
complex and challenging Brazilian environmental legislation. As well as having to
meet the growing consumers demands regarding environmental preservation. This
is associated with what they willing to consume and pay a premium price when
perceiving the producer alignment with their values [44].
13.5 Canadian-Type Biodigester or Covered Lagoon
The Canadian biodigester is a horizontal biodigester that has a rectangular base and
a gasometer made of a flexible PVC blanket that surrounds the base. It has greater
width than depth, resulting in a greater area of exposure to the sun, which contributes
to the increase in biogas production (as the heat retention provides greater bacterial
activity). This model is also known as covered lagoon, navy or balloon. It has low
cost of implementation, easy maintenance and cleaning, with the disadvantage of