Biogas

Biogas usage options

Biogas is a renewable fuel that can be used in a number of ways. Biogas can be used in boilers to provide heat only, in combined heat and power (CHP) to generate electricity and heat or upgraded to biomethane and then injected into the gas network or used as a vehicle fuel.

Ramboll has extensive experience of advising clients on either method. We also advise on the development of gas networks for biomethane where there is no existing infrastructure.

Biogas upgrade

Biogas consists of methane, carbon dioxide, hydrogen sulphide, water vapour and other minor constituents and particulates. The methane, and hence the energy, content of the biogas can increase by removing the other constituents to a content of 98% or greater. In this form, biomethane is suitable for injection into the gas network or used as a vehicle fuel.

Ramboll has advised a number of clients on biogas upgrade to create high grade renewable fuel and removing the constituents which have the potential to corrode or cause mechanical wear.

There are a number of technologies available to remove CO2, which are continually being improved and new techniques developed. It is important to choose the most appropriate technology based on plant specific parameters.

Biogas as a vehicle fuel

Biomethane can be compressed or liquefied into Compressed BioGas (CBG) or Liquefied BioGas (LBG) and can be used as a vehicle fuel. Natural gas used as a vehicle fuel can provide 20-30% saving on carbon emissions.

For biomethane, greenhouse gas emission reductions can be as much as 100%.

Ramboll has been involved in preconstruction planning, design and inspection of a significant number of vehicle fuelling stations.

Anaerobic digestion of sewage sludge and organic waste

A city with a population of one million has the potential to generate 17,300,000 Nm3/year of raw biogas from sewage sludge. This is equivalent to 110 GWh; enough energy to provide heat and electricity to 4,400 households.

Alternatively, 280,000 homes can be supplied with heat and electricity from biogas generated from 8 million tonnes of organic waste.

Ramboll has vast experience of preparing anaerobic digestion (AD) plant business models.

The underlying analyses investigate appropriate composition and volumes, consider the security of feedstock, evaluate the potential energy production and digestate output, and identify and evaluate end markets. Once a conclusion on feasibility and scale of plant has been reached, Ramboll can select, design and procure the correct reception facilities and waste handling equipment and the AD plant itself.

Our services after the pre-study stage cover the entire project cycle from preliminary design, permit applications and EIAs to final design, tendering, supervision, commissioning and performance tests. We also perform periodical inspections and analysis of risks and operational safety.