Skip to main content

Reconversions and upgrading

With ASAC Green Gas technology it is possible to reconvert and upgrade your biogasfacility in a simple and greatly improved way. In fact thanks to the patented stripping hydrolysis and CO2 absorption system the plant in addition to be reconverted to biomethane will have a much improved biology, more efficient, more stable, with higher yields and less need for digestate spreading.


Solubilizes organic matter before entering anaerobic digestion by making even that portion of hard-to-digest organic matter available to bacteria

Higher yields (more biogas with the same biomass inputs)

Digestate more stabilized and absent of odor (residual methanigenic potential zeroed)

Increased biological stability (hydrolyzed biomass is more easily digested by anaerobic bacteria)


Converts nitrogenous substances to ammonium sulfate, removing them from the biomass entering the digesters

Possibility of also using nitrogen-rich biomass (poultry manure, FORSU, sludge…)

Improved anaerobic digestion (by removing ammonia within the digesters, anaerobic fermentation occurs better, without risk of acidosis and in a more stable manner)

Ability to adjust the stripping level (In ASAC’s patented system, the ammonia stripping level can be adjusted in a simple and automated way. The degree of nitrogen to be maintained in the digesters and thus in the output digestate can be chosen, optimizing any composting systems placed downstream of the process)


ASAC technology completely sequesters the CO2 in the biogas by converting it to bicarbonate. Consequently there are no CO2 emissions into the atmosphere and the GHG calculation always has optimal values even with input biomass from dedicated crops.


ASAC’s special patented alkaline hydrolysis phase greatly facilitates the anaerobic digestion phase by making the organic matter much easier to be digested, allowing much less retention time, and thus the digesters themselves can handle much more biomass. By using the same plant, biogas production can be increased without building new structures. For example, a 1MW electric plant, which can normally be converted to 250 Sm3/h of biomethane, can be converted to 500 Sm3/h and more with ASAC technology. Our engineers can verify and size the optimal conversion according to the existing facilities.

If the same capacity is to be maintained, it is possible to use one or more existing digesters for digestate storage, in accordance with the new biomethane decree, without having to carry out additional works.

ASAC technology is applicable for:

Plant facility

Find out more

Reconversions and upgrading

Find out more


Find out more

Biogas plants in cogeneration

Find out more