Biogas for the future
Over the past decade, production capacity of biogas has more than doubled, as interest in this sustainable solution has spiked in line with global warming alerts and growing emissions targets. Currently, around two-thirds of the world’s biogas is produced in Europe, which is where production technology is currently concentrated.1
Environmental solutions for “Green” energy are one of the 2030 horizon targets in Europe, with up to 27% (and most probably 35% in the EU) renewable energy in the energy mix.
European production of biomethane was around 1.5 billion Nm3 in 2015 and is expected to rise to 150 billion Nm3 in 2030. Asia is also focusing on this energy source — particularly in China, where biogas units have been under development since 2019 to support the installation of largescale cogeneration plants. In North America development has so far been limited compared to other parts of the world. This situation may change in coming years with an increasing interest in agricultural waste as a biogas source.
From biogas to biomethane
Biogas is a raw material derived directly from various waste streams. It forms a feedstock to produce biomethane, with the final purity requirements depending on the biomethane end usage.
The many sources of biogas include landfill gas, sewage sludge, anaerobic digestion and thermochemical processes.2
The challenge for suppliers is to anticipate which biogas sources can become commercially viable for mass production when it comes to downstream uses.
Dealing with such varied source material creates real challenges when it comes to producing biomethane that reaches the same purity specification as natural gas and can therefore be injected into the national gas grid.3 At the moment, biomethane production accounts for around 10% of biogas conversion in total (the other 90% is biogas used directly in co-generation units to produce electricity/heat). And already, 18 countries in Europe are bringing some level of biomethane into their natural gas supply network.4 However, choosing the right biogas purification medium, at the right dosage level, remains a challenge, especially when the source of the biogas is so diverse from one plant to the next, meaning the impurities it generates can be so different.
Solutions to watch out for
Improved activated alumina to selectively remove particles from a hydrocarbon stream. These can include small polar molecules such as CO2, CO, COS and CS2, as well as large molecules with polarity, such as polar oxygenated/sulfurised/nitrogen compounds.
Silica gel to catch heavier hydrocarbon molecules from a natural gas or biogas stream.
Activated bed support via specific activated alumina with high crush strength performance, used to dry hydrocarbon flow before any other purification step.
Defoamers to reduce foam in the digester during the biogas production process.