#09 | LIFE NIMBUS: Rolling towards carbon neutrality and energy transition

By Aigües de Barcelona 

In the current context, expressions such as climate emergency, war, energy crisis, globalization, lack of raw materials and inflation become a real and everyday combination of unfavorable events. In view of this situation, projects such as Life Nimbus allow us to move forward towards disarmament and reduction, albeit modest, of these circumstances.

The energy transition urges us. It is necessary to contribute to the decarbonization of the planet. Therefore, it is necessary to drastically reduce the use of fossil fuels by energy sources without carbon emissions based on renewable sources. It is essential to make this transition as fast as possible. The European Union has designed a plan aimed at achieving climate neutrality by 2050, an economy with zero net greenhouse gas emissions. A date too far? The answer seems clear: yes.

LIFE NIMBUS is expected to reduce the carbon footprint of a public bus by more than 85% by using biomethane as fuel.

But, what exactly is carbon neutrality?

When the same amount of CO2 is emitted into the atmosphere as what is captured naturally through the oceans and terrestrial ecosystems, for its transformation into oxygen, we achieve the so-called zero carbon footprint. Today, the balance is clearly negative. The atmosphere naturally absorbs around 11 Gt (Giga tonnes) of CO2 per year compared to the 38 Gt of CO2 emitted.

Achieving carbon neutrality involves accelerating the energy transition. Beyond energies such as wind and solar that help us electrify the grid with green and renewable energies, there are many more vectors that can contribute to achieving this purpose and that must be strengthened and evolved from now on.

Capture and storage of CO2 in geological formations, fire control, energy efficiency and the reduction of consumption, self-consumption, generation of hydrogen and biomethane from the biodegradability of biomass, carbon offsets through certificates of origin, etc. are just part of a list of initiatives that today should be fully evolved and implemented in a global way.

Taking advantage of biogas as an energy source, from the biodegradability of organic matter in urban wastewater generated by people, Life Nimbus, a European-funded project, aims to demonstrate Power-to-Gas (P2G) technology based on biological processes: production of bio-H2 through a bio-electrochemical system (BES) and biomethane production through biological methanation. The project aims to contribute to sustainable mobility through the use of biofuel to promote the circular economy between ecofactories and urban transport in cities.

Specifically, an increase of almost 70% of the energy obtained from biogas is expected due to the storage of renewables through biological methanation; a reduction in the carbon footprint of a public bus by more than 85% by using biomethane as fuel; the production of 4 Nm3/h of biomethane through biogas biological methanation that will be used to power a public bus that will travel 48,000 km with renewable biofuel; and finally a 9% reduction in CO2 emissions on the bus line where the biomethane-powered bus will be tested (with a total fleet of 10 buses).

Life Nimbus, a small-scale demonstration project that should contribute to promoting on a large scale new ways of understanding the global management of our infrastructures from an environmental point of view, favoring the energy transition to find carbon neutrality to be long before 2050.