Biogas compression and oxygen generation in biogas plants

Biogas plants are transforming the energy scenery, similar to how lithium-ion batteries are powering the electric vehicle revolution. By efficiently converting organic waste into valuable biogas, these plants significantly reduce CO2 emissions and lower the environmental impact.

Optimize your biogas production process with the correct combination of the most sustainable equipment, including air and gas compressors, dryers, filters, and gas generators. With a focus on low life cycle costs, our installations ensure a constant supply of high-quality, dry, and unpolluted air.

No matter where biogas comes from, like digesters in sewage plants, landfills, or farms, biogas requires transportation for compression, purification, and separation.

 
For this application, you need a powerful gas blower. It should be able to handle raw gas without any pretreatment or purification. Additionally, it should be highly reliable and long-lasting. Our ZM blowers can handle raw biogas, transport it for purification, and produce methane and CO2 with low maintenance.

We all know by now that CO2 – when released into the atmosphere – triggers unwanted climate effects. Therefore, it’s a major concern for biogas stations to capture this CO2 and prepare it for re-use, injection into a CO2 pipeline, or underground storage.

You typically need to compress the CO2 to a pressure of around 20 bar for re-use.

Our oil-free CO2 compressors bring the CO2 gas to these desired pressures. You need an oil-free solution to maintain high-quality CO2 for reuse in industries like Food & Beverage, ensuring its purity. The capturing and re-use of CO2 play a major role in the transition to a low-carbon economy. Atlas Copco has a whole portfolio of CO2 products that will help you in this challenging journey.

Different processes like water scrubbing, amines scrubbing, membranes, Pressure Swing Adsorption (PSA), and cryogenic distillation upgrade biogas into biomethane. All these methods of upgrading require a biogas compressor to push and increase the pressure of the biogas from the digester to the upgrading process from usually atmospheric pressure up to 15 barg. 

You can do this by using the Atlas Copco GG screw compressor. Once you upgrade it, you can reinject the biomethane into the gas grid by using an additional compressor, depending on the gas grid pressure. Biomethane can fill vehicles on a CNG refuelling station by taking them from the grid and using compressors with outlet pressure up to 250 barg, using the same accounting principles of green electricity. Our CU or BBR CNG piston compressors can accomplish this. 

Oxygen (O2) has several applications in biogas production.

One of the harmful byproducts of biogas production is hydrogen sulphide (H2S), which must be removed from the biogas flow across the plant as it is corrosive and can damage downstream equipment.

Oxygen dosing is the most sustainable and cost-effective method of removing hydrogen sulphide. The oxygen is microdosed into the headspace of the digester where it removes the sulphur. As a result, on-site oxygen generation is the ideal solution for biogas plants.

The OGP & OGP+ ranges supply oxygen concentrations from 90% to 95%. If your application only requires 93% purity for example, this is what the oxygen generator will supply at the touch of a button - there is no need to pay for a higher purity than is necessary. This means that on-site generated oxygen comes at a lower cost per unit than bottled or liquid oxygen.

Our advanced monitoring, control, and connectivity features allow you to optimize performance and efficiency.

The central controller Optimizer 4.0 is the ideal solution to manage the complexities of controlling multiple compressors. The central controller monitors the fluctuating air demand 24/7. It automatically selects the most optimal configuration of multiple compressors to run at the lowest possible energy consumption.