Efficient and Environmentally-Friendly Production of Biomethane

The biogas upgrading process from Carbotech is a simple procedure: The raw biogas is first compressed, following the condensation of water content through a temperature exchange system and finally trace elements, such as hydrogen sulfide (H2S), will be removed with activated carbon.

The conditioned biogas is finally channelled through the PSA filter which is filled with carbon molecular sieves, especially designed for adsorbing the typical elements found in biogas. CO2, H2O, residual H2S, siloxane, NH3 and odours are then removed. Furhtermore through the patented Carbotech system, oxygen and nitrogen are partially removed. The result is a highly enriched methane gas referred to as biomethane.

The production of biomethane in each vessel runs through specific intervals and the plant switches to another filter while the first one is fully regenerated by means of vacuum. The programmable logic control (PLC) and the online gas analysis ensure an automated, safte and reliable operation.

Economical treatment process

The pressure swing adsorption (PSA) process from Carbotech is a dry biogas upgrading process with low operational costs. The means:

  • No process water, no process water conditioning
  • No waste water, no waste water treatment
  • No chemicals
  • No off gas with toxic contaminants

As an option, the ZETECH4® system can be implemented. It represents a unique and patented process for upgrading biogas, free from emissions, that meets international environmental regulations. In addition, it increases the methane gas yield and improves the overall efficiency through the patented heat recover technology.


Biogas production, upgrading and gas to grid injection plants from a single source


Economical planning and future proof investment in sustainable energy

Carbotech makes a vital contribution to the development of sustainable energy systems with its operationally reliable and environmentally responsible plants for the upgrading and gas to grid injection of biomethane gas.

For 2020, the Federal Government (of Germany) set a target of six billion cubic meters of biomethane to be fed into the natural gas grid. According to the latest survey, Germany consumed around 100 billion standard cubic meters of natural gas.
According to a calculation by the Federal Department for Food, Agriculture and Consumer Protection (BMELV), every year approximately 100 industrial biomethane gas to grid injection systems should be built to achieve this target.

An ambitious goal, to which Carbotech makes a vital contribution with its durable and efficient technology. The know-how of Carbotech includes every step, from project planning support, through engineering and building as well as commissioning of biogas upgrading plants and gas to grid injection systems.

For this it makes no difference whether the investor or the user decides in favour of producing raw biogas for use in a dry or wet fermenter.


How much gas can be produced?

The amount of gas which can be produced is primarily defined by the type and amount of feedstock is available. The use of different feedstocks such as manure, silage, sewage or mixtures will define the amount and quality of the raw biogas which is in the following upgraded in Carbotech Biogas Upgrading Plants to biomethane/Bio-CNG.

Schmack Carbotech is a supplier of turn-key Biogas Upgrading Plants (BUP) in the range of a few hundred up to a few thousand cubic meters. With our optimized container modules in the range of 200-3000 Nm³/h we can ensure best technology, clear battery limits and easy erection process. Due to our vast experience we are capable to adjust our units according to your specific needs.

The upgrading of biogas via pressure swing adsorption (PSA) is state of the art and possesses the following advantages:

  • single stage removal of CO2 & H2O & NH3 & CxHy, Siloxanes, N2/O2
  • high product quality, up to 99 % CH4 
  • high methane recovery, > 99%
  • no dilution of biomethane with O2/N2 
  • dry process, no process water or liquids
  • no chemicals, no waste materials
  • automatic part load adjustment 30 to 110%
  • very power efficient 0,16 to 0,24 kW/m3
  • no plant performance degradation over time

Biogas upgrading plants (BUP)

The BUP standard series includes all of the features already described: safety, economy, reliability and a compact design as well as easy operation and maintenance. The turn-key containerised design ensures low installation cost and rapid commissioning: only power and gas needs to be connected to be able to produce from biomethane of high purity biogas.

Biomethane Gas to Grid Injection Plants (BtG)

The entire gas to grid injection plants is designed, built and tested in accordance with the German Gas Regulations and Standards (DVGW). The complete conainerised system is pre-assembled and fully tested at the factory. As a result, installation and commissioning on site take little time.

Subject to local requirements, the gas to grid injection plant can compromise the following system components:

  • Gas pressure control equipment
  • Biomethane booster station 1-/2-/3-stage compression systems subject to pressure grid type. The constellation redundancy can be offered 2 x 50 %, 3 x 50 %, 2 x 100% capacity
  • Oxygen extraction module (EASEE gas requirement)
  • LPG or air enrichment system
  • Air admixing system
  • Odorising station
  • Gas quality and flow instrumentation


Because of the highly efficient process with well-developed reliable and durable systems that meet international standards, the exceptional low consumption will be reflected in the specific operating costs, as well as the life cycle costs. In industrial plants, average costs are less than €0.01/kWh.

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