Gas liquefaction

Biogas treatment: How to upgrade biomethane to natural gas quality

Biogas treatment is an important step in energy production that allows biomethane to be converted to natural gas quality. In this article, we will take a closer look at the biogas treatment process, the technologies used for it and the benefits and challenges of this method. We will also take a look at the future prospects of biogas treatment and the current research and development activities in this field.

What is biogas treatment?

Biogas consists mainly of methane and carbon dioxide. During biogas treatment, the resulting biogas is purified and brought to natural gas quality. This allows the biomethane to be used in conventional natural gas applications such as energy generation, heating or fuel production.

During biogas treatment, the biogas is first cleaned of impurities such as hydrogen sulphide, water vapor and other trace gases. Carbon dioxide is then separated from the methane. This process increases the methane content in the biomethane. This is done in various stages and using technologies that are explained in more detail in the next section.

Biogas treatment plays an important role in sustainable energy production. Biomethane produced from biogas and upgraded to natural gas quality can be used as a renewable energy source. The use of biomethane can reduce fossil fuels and CO2 emissions.

In addition, the processed biomethane can be used in existing natural gas infrastructures. The integration and usage of the biogas methane is facilitated. Biogas treatment also has a positive impact on agriculture. It enables the use of organic waste such as slurry, manure and plant residues to generate energy. As a result, this waste can be recycled efficiently and helps to reduce environmental pollution. The technologies for biogas treatment are diverse and are constantly being further developed. One example is pressurized water scrubbing, in which the biogas is passed through a liquid to remove impurities. Another method is activated carbon filtration, in which the biogas is passed through activated carbon to remove odorous substances and other impurities. Biogas treatment requires careful monitoring and maintenance to ensure efficient and reliable production of biomethane. This includes regular inspections of the plants, checking the process parameters and, if necessary, carrying out cleaning and maintenance work.

The role of biomethane in energy generation

Biomethane is a renewable energy source that plays an important role in reducing the carbon footprint of energy production. It can be used as an alternative to fossil fuels such as natural gas or coal. It therefore helps to reduce greenhouse gas emissions. Biomethane can be used to generate electricity, heat buildings or produce biofuels.Germany is one of the countries that rely on biomethane as a sustainable energy source. There are a large number of biomethane plants in the country that convert organic waste such as agricultural residues, liquid manure or biowaste into biomethane. These plants play an important role in the energy transition and contribute to achieving climate targets.The use of biomethane also has a positive impact on agriculture. The use of agricultural residues not only generates renewable energy, but also produces high-quality fertilizer that helps to improve the soil.

Natural gas tank
Natural gas tank
Biogas treatment has great potential for sustainable energy production and is being intensively researched and further developed worldwide.

The process of treating biomethane to natural gas quality

The process of treating biomethane to natural gas quality also includes the desulphurization of biogas. Desulphurization is obtained from the anaerobic fermentation of organic materials. The biomethane often contains undesirable sulphur compounds such as hydrogen sulphide (H2S). It is necessary to remove these sulphur compounds in order to bring the biomethane to natural gas quality.

There are various technologies that can be used to process biomethane to natural gas quality. In addition to pressurized water scrubbing, the membrane separation process and chemical scrubbing, biological desulphurization is also used.

In pressurized water scrubbing, the biomethane is washed with water under pressure to remove impurities such as hydrogen sulphide and carbon dioxide. This purifies the biomethane and brings it up to natural gas quality by also removing the sulphur compounds.

Plant for the production of liquid gas
Plant for the production of liquid gas

The membrane separation process

The membrane separation process uses special membranes to separate the impurities in the biomethane. The unwanted gases, including sulphur compounds, are separated by selective permeation. The biomethane is converted to natural gas quality.
Chemical scrubbing is another process in which the biomethane is brought into contact with a chemical solution to remove the impurities, including the sulphur compounds. The chemical solution binds the unwanted gases and the purified biomethane can be used as natural gas.
The choice of treatment technology, including biogas desulphurization, depends on various factors, such as the composition of the biomethane and the natural gas quality requirements.
Overall, biogas desulphurization plays a crucial role in the treatment of biomethane. The removal of sulphur compounds purifies the biomethane and optimizes it for feeding into the existing natural gas grid and for versatile use as natural gas quality.
When upgrading biogas to methane using cryogenic refrigeration, moisture is first removed from the biogas in a drying process. Condensation or absorption processes are used to remove water and other volatile compounds from the biogas.
This is followed by the actual treatment of the biogas to methane quality by dehumidification. Residual moisture and volatile organic compounds are further removed through the use of cryogenic cooling in order to obtain high-purity methane gas. This step is particularly important in order to improve the quality of the biogas and make it suitable for various applications such as feeding it into the natural gas grid or using it as a fuel.

Advantages and challenges of biomethane treatment

Biomethane as a renewable energy source contributes to the reduction of greenhouse gas emissions and enables sustainable energy production. Furthermore, biogas treatment offers the possibility of producing biomethane from waste products such as agricultural residues or organic waste, which leads to a more efficient use of resources.

Biogas treatment is associated with technical and regulatory challenges. The selection of suitable technologies and compliance with environmental standards require expertise and investment. In addition, the legal framework and funding programs are crucial for the further development and spread of biogas treatment.

Future perspectives for biogas treatment

Current research activities are focused on improving biogas treatment technologies, increasing efficiency and reducing costs. New methods are being developed to optimize the upgrading process and enable the use of biomethane in various applications.The increasing demand for renewable energies and the need to reduce the carbon footprint open up promising future prospects for biogas treatment. Renewable energy can be used on a large scale by integrating biomethane into existing natural gas infrastructures.Biogas treatment is an important technology for sustainable energy production. The process of upgrading biomethane to natural gas quality allows renewable energies to be used efficiently and CO₂ emissions to be reduced. With further research and development activities, biogas treatment will play an even greater role in energy generation in the future and contribute to a more sustainable energy future.

Maschine engine of a biogas treatment plant
Maschine engine of a biogas treatment plant
Christian Berger

CSL Behring

Christian Berger · Global Director - Process and Technology Owner for Aseptic & Sterility

Refolution supported me in the technical verification of design and dimensioning of a Natural Refrigerant Cooling System for a new Freeze Dryer system.
I was very happy with the immediate support and competence of the Refolution Team. Thanks for your help.

Find suitable products for the realization for solvent recycling

Our services