The advantages of ASAC's patented
technology in 10 points 1. The system is extremely quiet, with a noise level of just 45 dB(A)

The patented ASAC technology captures the CO₂ present in biogas and transforms it into calcium bicarbonate, thus eliminating CO₂ gas emissions.

  1. Since it does not emit CO₂, the ASAC system does not require the recovery of CO₂ gas, which is generally a complex and costly operation, as well as difficult to manage. In fact, recovered CO₂ is not generally suitable for food use without further investment.
  2. No off-gas post-combustion required
  3. High-quality biomethane, CO₂-free in compliance with UNI 11537-2019

The patented ASAC hydrolysis section allows difficult biomasses, such as poultry manure, FORSU, civil or industrial sludge, to be easily used even without the addition of further organic matrices, reaching advanced biomethane standards.

The patented ASAC technology involves an innovative first hydrolysis phase, which allows for the complete volatilization of nitrogenous substances in the form of ammonia, which is converted into ammonium sulfate that can be used in agriculture. As a result, the solid digestate is nitrogen-free.

  1. Solid digestate does not require composting and can be used as a soil improver outside the scope of the Nitrates Directive.
  2. Thanks to hydrolysis treatment, both liquid and solid digestate is nitrogen-free and well digested, and therefore has no unpleasant odor.
  3. Nitrogen is recovered in the form of ammonium sulfate, a fertilizer that is easy to store, manage, and sell.

Reducing the volume of anaerobic fermentation not only means less space is required, but also lower thermal and electrical requirements for pumping and mixing. Furthermore, energy-intensive downstream treatments such as composting and nitro-denitro are not necessary. Throughout the process, the biogas remains at atmospheric pressure, avoiding the energy costs of compression that are necessary in membrane or PSA systems.

  1. Overall electricity and heat consumption is minimized and easily covered by the installation of a small biogas-powered cogenerator.
  2. Heat recovery from the hydrolysis phase with preheating of the initial sludge
  3. Biogas is always kept at atmospheric pressure.

The ASAC system is suitable for small and large plants, without any operational or management difficulties, as it is a simple chemical-physical process that is easy to implement. Furthermore, as it requires half the anaerobic digestion volumes, it is possible to double production capacity in the case of conversions and upgrades from biogas to biomethane. For example, a 1MW electrical plant currently operating to produce electricity from biogas can be converted and upgraded to 500 Sm3h of biomethane while retaining the same fermenters.

The patented ASAC technology saves money in terms of both investment and operating costs:

  1. Civil structures (digesters, storage facilities, post-treatment facilities) reduced to a minimum
  2. No storage or spreading costs for liquid digestate, which is disposed of in the sewer system
  3. Minimum costs for spreading solid digestate as a soil conditioner
  4. Maximum yield from anaerobic fermentation means making the most of the available biomass.
  5. Minimal self-consumption means minimal operating costs
  6. The sale of ammonium sulfate as fertilizer recovers most of the operating costs.
  7. A simple and reliable system means less downtime, easier maintenance with standardized components, and, above all, no costs for special components (membranes, PSA regeneration, steam boiler management and operation, etc.).

The patented ASAC hydrolysis system significantly reduces fermentation times:

  1. Small size with much smaller anaerobic digestion volumes compared to traditional technologies

Thanks to the special hydrolysis system developed and patented by ASAC, organic matrices are much easier to digest, facilitating the anaerobic fermentation process and allowing nitrogen stripping upstream of the system, completely avoiding the risk of ammonia formation in the digesters.

  1. Maximum efficiency (hydrolysis ensures maximum biogas production, with negligible unfermented residue)
  2. Biological stability (hydrolyzed sludge enters the digester completely free of ammonia, which is toxic to methanogenic bacteria, thus providing perfect conditions for anaerobic digestion, which occurs in a very stable manner).

The patented ASAC technology allows for very compact dimensions compared to traditional technologies:

  1. Reduced digester volume
  2. Absence of composting
  3. Absence of nitro-denitro treatments
  4. No digestate storage

The patented ASAC technology allows for the intensive stripping of nitrogen and the complete degradation of organic substances during anaerobic fermentation; as a result, the liquid digestate output is suitable for disposal into the sewer system (Wastewater – Emission limit values
Annex 5, Part Three, Legislative Decree No. 152/06 – Table 3 "discharge into the sewer system") through simple separation of solids and possible passage through a small oxygenation tank.

  1. No nitro-denitro treatment plants required
  2. No need to spread digestate (digestate can be discharged into the sewer system)

ASAC GREEN GAS is not simply an upgrade from biogas to biomethane, but a complete and innovative anaerobic fermentation process, in which organic matrices are better digested, produce more, and leave no residue.

Choose ASAC GREEN GAS for a zero-emission system: the only system with completeCO2 capture.

See our pilot plant

BIOMETHANE PLANT WITHCO2 SEQUESTRATION

After hydrolysis, the sludge is sent to a mesophilic anaerobic digestion phase. Compared to a traditional system,the sludge is much easier to digestbecause, on the one hand, ASAC hydrolysis has solubilized the COD, making it easily available to methanogenic bacteria, and, on the other hand, it has also eliminated all the ammonia, a toxic substance that inhibits anaerobic bacteria. Ultimately, the anaerobic digestion process under these conditions takes place in less time and with greater efficiency, producing a digestate with very low COD, BOD, and nitrogen values that is suitable for direct discharge into the sewer system, after separation of the dry matter by thickening and/or centrifugation or filter pressing. The reduction in the time required for the entire anaerobic digestion process for the greatest possible recovery of biogas can be significantly reduced, especially for difficult biomasses such as poultry manure and FORSU. In addition, the methane residue is reduced to a minimum and, in fact, more gas is produced than with traditional technologies.

Any type of organic matrix, even biomass that is difficult to treat, such as: poultry manure, FORSU, sewage sludge, industrial sludge, waste with a high ammonia content.

Recirculation system for minimizing water requirements

With this technology, anaerobic digestion volumes are extremely low compared to other technologies. This means, in addition to taking up less space, it reduces the thermal and electrical requirements for pumping and mixing. Furthermore, energy-intensive downstream treatments such as composting and nitro-denitro are not necessary. Throughout the process, the biogas remains at atmospheric pressure, avoiding the energy costs of compression, which are necessary in membrane or PSA systems. Self-consumption is easily covered by a small cogenerator, possibly supplemented by a small biogas boiler.

In this section, organic matrices are dosed and prepared by fine grinding, preheating with heat recovered from the process, and mixing to obtain a pumpable slurry to be sent to the subsequent sections.

The patented ASAC technology allows for the intensive stripping of nitrogen and the complete degradation of organic substances during anaerobic fermentation. As a result, the liquid digestate output is suitable for disposal in the sewer system (Legislative Decree 152/06) through the simple separation of solids and possible passage through a small oxygenation tank. No nitro-denitro treatment sections are required. No spreading of digestate is necessary (the digestate can be discharged into the sewer system).

The patented ASAC technology allows for the production of high-purity biomethane suitable for injection into the grid in compliance with current regulations.

In this section, the sludge is treated using an innovative hydrolysis process developed and patented by ASAC, in which organic substances are solubilized and made more digestible. In addition, nitrogen compounds are converted into gaseous ammonia, which is then recovered in the form of ammonium sulfate through a sulfuric acid scrubber. What is carried out in this phase is not a simple hydrolysis as is usually the case in normal pre-treatment plants, but a hydrolysis specially optimized for ammonia stripping and the solubilization of organic substances, with very high efficiency. In this phase, an initial upgrading step takes place, where a portion ofthe CO2 present in the biogas is absorbed and converted into calcium bicarbonate. At this stage, the process also allows for the complete purificationof H2Sand other unwanted components in the biogas. The final step of the ASAC process is the upgrading and final purification of the biogas into biomethane, which takes place through a second step of convertingCO2 into calcium bicarbonate.

1
After hydrolysis, the sludge is sent to a mesophilic anaerobic digestion phase. Compared to a traditional system, the sludge is much easier to digest because, on the one hand, ASAC hydrolysis has solubilized the COD, making it easily available to methanogenic bacteria, and, on the other hand, it has also eliminated all the ammonia, a toxic substance that inhibits anaerobic bacteria. Ultimately, the anaerobic digestion process under these conditions takes place in less time and with greater efficiency, producing a digestate with very low COD, BOD, and nitrogen values that is suitable for direct discharge into the sewer system, after separation of the dry matter by thickening and/or centrifugation or filter pressing. The reduction in the time required for the entire anaerobic digestion process for the greatest possible recovery of biogas can be significantly reduced, especially for difficult biomasses such as poultry manure and FORSU. In addition, the methane residue is reduced to a minimum and, in fact, more gas is produced than with traditional technologies.
2
Any type of organic matrix, even biomass that is difficult to treat, such as: poultry manure, FORSU, sewage sludge, industrial sludge, waste with a high ammonia content.
3
Recirculation system for minimizing water requirements
4
With this technology, anaerobic digestion volumes are extremely low compared to other technologies. This means, in addition to taking up less space, it reduces the thermal and electrical requirements for pumping and mixing. Furthermore, energy-intensive downstream treatments such as composting and nitro-denitro are not necessary. Throughout the process, the biogas remains at atmospheric pressure, avoiding the energy costs of compression, which are necessary in membrane or PSA systems. Self-consumption is easily covered by a small cogenerator, possibly supplemented by a small biogas boiler.
5
In this section, organic matrices are dosed and prepared by fine grinding, preheating with heat recovered from the process, and mixing to obtain a pumpable slurry to be sent to the subsequent sections.
6
The patented ASAC technology allows for the intensive stripping of nitrogen and the complete degradation of organic substances during anaerobic fermentation. As a result, the liquid digestate output is suitable for disposal in the sewer system (Legislative Decree 152/06) through the simple separation of solids and possible passage through a small oxygenation tank. No nitro-denitro treatment sections are required. No spreading of digestate is necessary (the digestate can be discharged into the sewer system).
7
The patented ASAC technology allows for the production of high-purity biomethane suitable for injection into the grid in compliance with current regulations.
8
In this section, the sludge is treated using an innovative hydrolysis process developed and patented by ASAC, in which organic substances are solubilized and made more digestible. In addition, nitrogen compounds are converted into gaseous ammonia, which is then recovered in the form of ammonium sulfate through a sulfuric acid scrubber. What is carried out in this phase is not a simple hydrolysis as is usually the case in normal pre-treatment plants, but a hydrolysis specially optimized for ammonia stripping and the solubilization of organic substances, with very high efficiency. In this phase, an initial upgrading step takes place, where a portion ofthe CO2 present in the biogas is absorbed and converted into calcium bicarbonate. At this stage, the process also allows for the complete purificationof H2Sand other unwanted components in the biogas. The final step of the ASAC process is the upgrading and final purification of the biogas into biomethane, which takes place through a second step of convertingCO2 into calcium bicarbonate.


plant turnkey


conversion service .


maintenance service

REQUEST FOR INFORMATION