REVISTA DYNA ENERGÍA

Key words:

digestión anaerobia, limpieza del biogás, refinado del biogás, biometano, gas de vertedero, sustituto del gas natural, residuo orgánico, anaerobic digestion, biogas cleaning, biogas upgrading, biomethane, landfill gas, natural gas substitute, organic waste.

Article type:

COLABORACION/COLLABORATION DAMR

Section:

COLLABORATIONS

Biogas production is growing nowadays due to the increasing installation of anaerobic digesters for organic waste treatment, promoted by the current environmental legislation. Depending on the final use, different biogas treatment steps are necessary since the biogas is mainly composed of methane, but also carries carbon dioxide and other minority substances such us hydrogen sulfide, oxygen, nitrogen, water, ammonia, siloxanes and particulates.
In the last years, there is also an increasing demand for methane-rich biogas (biomethane) since the use of this product as vehicle fuel or its injection to the natural gas grid are becoming common practices. This supposes the biogas has to be first cleaned to remove the trace elements and then upgraded to remove CO2 and adjust the calorific value to the foreseen uses. Biogas upgrading is thus a key issue today to enrich biomethane to produce a natural gas substitute.
This paper evaluates not only the biogas upgrading technologies that are commercially available today (as pressure swing adsorption, scrubbing using different types of absorbers, and gas permeation membranes), but also those that are under development trying to achieve lower investment and operational costs and, at the same time, higher methane content in the upgraded biogas (as membrane contactors, cryogenic upgrading, ecological lungs or in situ methane enrichment).