Transport in the Emilia Romagna Region was noted as being responsible for 90% of total CO emission, 46% of NOx, 41% of primary PM10, and 42% of total non-methane volatile organic compounds (NMVOC). More specifically, CO2 emissions from the road transport sector in this region were the second highest in Italy, representing 30% of total regional emissions.
A hydro-methane gas blend of transportation fuel had been proven to give very positive performance both from an environmental and energy perspective. A study carried out for the Emilia-Romagna Regional Government reported that a mix of 15% hydrogen and 85% natural gas significantly reduced CO2 and atmospheric pollutants emissions. Moreover at these percentages, the overall energy balance of the system – including hydrogen production through a steam reforming process – compared favourably to the same vehicle fuelled with natural gas.
The MHyBus project aimed to reduce negative environmental impacts from the public city passenger transport sector (in terms of CO2 and air pollutants emissions). This would be achieved through the use of a gaseous fuel blend for buses of up to 20% hydrogen and 80% natural gas (in short “hydro-methane”). The project sought to implement the first prototype hydro-methane bus and to support the spread of this technology through regional policy measures. It planned to increase awareness in the Emilia-Romagna region about climate change and air quality topics through the active demonstration of the prototype vehicle.
Expected project results were:
- Optimising the percentage composition of the hydro-methane blend (of up to 20% hydrogen and 80% natural gas);
- Verifying the functioning of the prototype fuel supply system and its components;
- Developing a public transport city bus prototype able to use hydro-methane (developed from an existing bus fuelled by natural gas);
- Developing a standardised procedure for the prototype bus (which may be used to transform the entire bus fleet);
- Experimental results with valuable and important reference for the diffusion of the hydrogen technology in the transport sector (e.g. acting as a starting point for the improvement of air quality and tackling climate change);
- Regional technical guidelines for the conversion of the natural gas fuelled buses currently in circulation to hydro-methane fuelled buses.
MHyBus has performed the necessary steps to put the first hydro-methane prototype bus on urban roads and has monitored its performance.
After testing at the test bench, the validation and the on-board installation of a modified engine, apt to be powered by a hydro-methane blend with 15% of Hydrogen, the prototype bus has circulated on public roads for over one year. In line with the prescriptions of the Experimental Programme required by the Ministry of Transport Motorvehicle Test Centre, the first 5.000 km were accomplished with ballast on-board, and further 41.000 km were run with passengers on-board in the regular public service of Ravenna. The competent authority carried out intermediate and final verifications of the engine and other components subject to wear in the methane-hydrogen environment during the experimental phase: no technical problems were detected and the Ministry of Transport eventually acknowledged the end of the experimental circulation and authorised the bus to run in full service for two additional years after the project end-date.
The project demonstrated the advantages of hydro-methane: reduction of atmospheric pollutants emissions and reduction of fuel consumption. Measurements showed that hydro-methane leads to a reduction of 15% of CO2 emissions and decreases methane consumption by 13% with respect to a methane fuelled vehicle. The project has also demonstrated that the direct use of hydrogen in methane fuelled vehicles is possible without mechanical modifications; that the safety aspects are similar to methane; that the costs for vehicle upgrading are moderate. The limited additional annual fuel costs are feasible especially when considering the environmental benefits linked to the use of hydro-methane. During the 45 000 km road test, MHyBus saved 5.98 tonnes of CO2 emissions, and 1.8 tonnes of methane.
As transport is responsible for 32% of the overall CO2 emissions in Emilia-Romagna (ARPA, 2013), and for 30.8% of total energy consumption, the reduction of emissions and of fuel consumption could have a significant impact at the regional scale. Environmental benefits as proved by MHyBus, if extended to the whole regional fleet, could lead to a saving of 2526 tonnes of CO2 emissions. Considering the latest estimation of external costs of CO2 in the transport section, this leads to a saving of 419 €/year per vehicle on external costs.
Project contributions to public transport policy include the production of new knowhow and tools for promoting hydro-methane technologies at the regional scale. Technical guidelines were produced covering the conversion of a bus fuelled with natural gas for urban circulation into hydro-methane fuelled counterpart. These guidelines contained a technical ‘to-do-list’ for public transport companies intending to replicate the MHyBus hydro-methane experience. The project has also demonstrated that the direct use of hydrogen in methane fuelled vehicles is possible without mechanical modifications; that the safety aspects are similar to methane; that the costs for vehicle upgrading are moderate. The limited additional annual fuel costs are feasible especially when considering the environmental benefits linked to the use of hydro-methane.
Project results also involved a Road Map for converting local public transport fleets to low impact fuel and in particular to the hydro-methane blend. The Road Map contains indications for further research and development activities in the field of sustainable mobility in the Emilia-Romagna region. In the Road Map, the different solutions put in place for sustainable mobility in Emilia-Romagna have been examined, such as the use of hybrid electric vehicles and comparisons were made based on the regional scenario. Because of the significant number of methane fuelled vehicles in the region, and thanks to simplicity of hydro-methane technology and to its relatively low cost, hydro-methane was considered to be a promising solution to reduce negative environmental impacts from regional public transport.
Considering the long-term perspective and the EU2020 targets, the extension of the hydro-methane technology needs to consider the whole life cycle of hydro-methane, and in particular its production considering modern hydrogen production technologies from renewable sources, such as hydrobiomethane. In fact, work has focused mainly on the conversion of the bus and the refuelling operation using the hydrogen production technology available at the experimental site. Further demonstrative projects should be developed focusing on emerging technologies for hydrogen production with nearly zero emission.
New high quality and green employment opportunities were foreseen as positive long-term impacts for the region from an expansion and/or further development of the project’s technology.
The project has raised wide interest as best practice in the Region, and the project consortium is in contact with other public transport companies to explore the possibilities of replicating the experiment (TPER, Bologna).
The project idea could be quite easily replicated in other cities or regions in Italy or the EU in order to reach legislation targets. In Italy, many cities have large methane-fuelled fleets (with up to 400 vehicles in Rome). It does not require the purchasing of new buses, but rather adapting existing vehicles, hence notably reducing the investment costs. Issues noted by the project included the importance of a reliable hydrogen supply chain for such technology. In Ravenna this logistical factor was facilitated by the presence of a hydrogen production plant located very close to the bus depots.
Policy links include complementarity with the Europe 2020 strategy; EU Action Plan on Urban Mobility adopted in 2009; and the European alternative fuels strategy of 2013. A major challenge to the project technology is the lack of a specific regulation on the use of hydrogen and hydro-methane as a fuel (and type-approval of relevant vehicles) at the EU and national level. Although the project's bus is no longer considered on experimental circulation (meaning de facto that the experiment is positively concluded), it is classified as an experimental vehicle and its authorisation is temporary. There are still no regulations ruling the release of a permanent authorisation. Also the fact that the current EU policy trends are towards zero-emissions public transport, may reduce the incentives for R&D of technologies that require the use, although reduced, of conventional fuels.
Yet, according to the project consortium, in a longer time perspective the diffusion of hydro-methane is also to be seen as a first step for the development of a hydrogen supply network starting from a demand of hydrogen. This is a crucial step for the transition of the whole transport sector to innovative low impact vehicles based on hydrogen (e.g. hydrogen fuel cell vehicles and hybrid vehicles).
A vital project legacy relates to the on-going interest in this hydrogen technology by the public transport company involved in the project, as well as the hydrogen producing companies. They have expressed their interest in using the MHyBus vehicle with hydro-methane and also extending the use of hydro-methane to a fleet of 10 vehicles.
Adopting clear legislation in this regard at the Italian or EU level would certainly help associated initiatives to introduce even more sustainable projects. It is worth mentioning that similar conclusions were drawn by another Italian project dealing with experimental hydro-methane powered vehicles, which has submitted its final report in 2014 (LIFE09 ENV/IT/000216 - H2POWER).