Non-IMpact BUS: Demonstration of a biological methanation plant for sustainable urban transport

PROJECT DESCRIPTION

BACKGROUND

The transport sector accounts for around 33% of the total primary energy consumption in Europe. In recent years, this sector is making progress towards the use of diversified energy sources, but more effort is needed. Within this context biomethane, being a renewable fuel, is starting to play a key role among sustainable road transport solutions. Furthermore, the EU directives 2009/28/EC and 2018/2001/EU on the promotion of the use of energy from renewable sources aim to achieve a share of 20% of energy from renewable sources by 2020 and 32% by 2030. The power sector can easily reach a higher share of renewable sources thanks to wind and solar technologies, but their applications are limited by the storage capacity of the grid. Currently, renewable power plants are often forced to reduce supply to the market during low-demand periods. The power-to-gas concept is a solution to store excess renewable energy when power generation is higher than demand. Thanks to this solution, renewable electricity generation can be used to obtain a renewable biofuel (biomethane), which can then be used for transport and thus contribute to reduce CO2 emissions by up to 88% compared to natural gas. Waste and wastewater treatment plants have a huge potential to produce biomethane from biogas methanation. The biogas produced in these plants is composed of around 60-65% of methane and 35-40% of CO2. Therefore, biogas methanation is a power-to-gas technology that could significantly increase the potential of renewable biofuel production.

OBJECTIVES

The objective of the LIFE NIMBUS project is to demonstrate the technical and economic feasibility of a power-to-gas solution based on biological processes. This will contribute to the increase of renewable energy production, and therefore reduce the carbon footprint. The purpose of the project is to produce biomethane from biogas that is of the quality required for use as a biofuel, therefore storing renewable energy that otherwise would be lost. For this purpose, a biological methanation plant using a mixture of hydrogen(H2) and bio-hydrogen (bio-H2) sources will be designed, built and operated. The biomethane produced will be used to fuel a public bus.

The projects objectives are fully in line with the milestones of the EU Roadmap to a Resource Efficient Europe (COM(2011)571) on increasing the use of renewable energy sources in the transport sector. More specifically, the project will contribute to the implementation of Directive 2009/28/EC and Directive 2018/2001/EU on the promotion of the use of energy from renewable sources.

RESULTS

Expected results:

Storage of 29 toe/year as biomethane using a power-to-gas technology, which means an improvement of 68% in the renewable energy produced in the wastewater treatment plant of Baix Llobregat compared with the current use of biogas in cogeneration motors;

Production of 4 Nm3/h of biomethane through biological biogas methanation that will be used to fuel one public bus, which will run 48 000 km on renewable fuel;

Reduction of 88% of the carbon footprint of one public bus (Well to Wheel footprint of 2.2 kgCO2 eq/km when using compressed natural gas (CNG) versus 0.3 kgCO2eq/km when using biomethane). This corresponds to a reduction of 72 tCO2/year and savings of 22 t/year of natural gas, a fossil fuel;

Reduction of 9% of CO2 emissions on the bus line where the biomethane-fuelled bus is tested (total fleet of 10 buses).

The expected results will be a basis to upscale after the project the developed technology in Barcelona, to increase the figure of biomethane powered buses up to 141, reducing 5940 toe/year. A second replication site in Ste is expected to power with biomethane up to 45 additional buses.