The research and experiments conducted in recent times on cogeneration by a genuine specialist in the field open up scenarios of the highest potential interest also for paper industry players, to whom they promise efficient and effective solutions that are naturally sustainable
“Given its notoriously energy-intensive nature, the paper production and converting sector is extremely interesting for suppliers of cogeneration technologies and solutions. The latter can contribute significantly to a reduction of up to 30% in energy expenditure, and the widespread and massive use of hydrogen should open up even more fascinating prospects. The obstacle is cost, which is still too high but is likely to fall within the next two years”. Speaking in these terms in an interview with Industria della Carta was Christian Manca, chief executive officer of the Italian subsidiary of 2G Energy AG headquartered in Heek in the North Rhine-Westphalia region of Germany and with around 8,000 cogeneration plants installed in 68 countries.
Rapid transition
300 of these are in Italy, where the supplier has been present with its headquarters in Vago di Lavagno (Verona) since 2011 and has a fruitful dialogue with companies in manufacturing, agriculture and services, to which it offers engines alternatively fuelled by natural gas, biogas or biomethane. If the CEO alluded to hydrogen, however, it is also because of the recent experience that the multinational company – more than 900 employees in total and a turnover of EUR 365 million in 2023 – has gained in the motherland. In cooperation with the University of Amberg-Weiden – Ostbayerische Technische Hochschule or OTH, in Bavaria – it has recently converted an existing cogeneration plant from traditional gas to hydrogen. This was a typical applied research project, thanks to which 2G Energy AG was able to further demonstrate how the transition to hydrogen is a viable path and, above all, how the transition can be successfully managed quickly and with low investment. In effect, the star of the initiative was a natural gas-powered cogenerator with an electrical capacity of 250 kilowatts, which will be fully operational as early as 2019 for teaching and research purposes.
The secret is modularity
The machines manufactured and marketed by 2G are distinguished by their modular design, which for upgrade operations such as the one described here has proved to be an undoubted and important advantage. “Our solutions,” noted Christian Manca, “are distinguished by their modularity: in order to be able to change the power supply, it is enough to replace or modify certain parts such as pistons and heads or other components that would have had to be replaced over time anyway. The idea is that currently companies or entities that are considering adopting a cogeneration plant should opt for a hydrogen-powered facility from the outset. There is nothing to prevent them from starting with natural gas and switching to hydrogen at a later stage, but facing an investment equivalent to only 17% of the initial investment. Regardless of the sources used, 2G Energy AG’s systems are proving to be competitive: from 38 per cent efficiency of the 250 kilowatt biogas machines, we have now reached 42.5 per cent”.
The blend of success
The aforementioned modular design of the Rhine manufacturer’s solutions was optimised in Amberg for the new fuel. The geometry of the combustion chamber was readjusted ad hoc and, in addition to the change in compression ratio brought about by the use of different pistons, the mixture formation process also had to be modified during the conversion. The latter, with the switch to hydrogen, must in fact take place directly in the combustion chamber. For this to occur, hydrogen must be introduced into the intake duct via a special gas injector, before the mixture – ready for ignition – can be fed into the combustion chamber. In addition to being easier to ignite than conventional gases, hydrogen also has a higher laminar flame velocity, which requires compressed air to be mixed with hydrogen only shortly before combustion to avoid uncontrolled ignition. According to the company, a further crucial aspect is the need to link maintenance and retrofit programmes to hydrogen conversion plans from the outset. Both the pistons and the 2G gas injectors, as well as the hydrogen-friendly turbo-compressor, have long since been standardised, so that they can be replaced or upgraded – as is already the case with regular overhauls – at a later stage, in which case the cost of the conversion can be reduced to 10-15% of the initial investment.
The role of software
Hardware is not the only decisive driver in the transition to hydrogen, quite the contrary. “With machines between 50 kilowatts and 1 megawatt,” argued the Italian CEO, “2G Energy AG can already manage it easily. However, applications developed to oversee the mixing and balancing of natural gas and hydrogen, which is already at the heart of 32 of our plants in Canada, Germany, Japan, and the Emirates, are indispensable to complete the whole process”.
2G first ventured into on-site electricity and heat generation using hydrogen in 2014. One of the first fully hydrogen-based CHP plants was realised as part of a multi-handed and multi-voiced project orchestrated by the Bavarian electricity supplier Stadtwerk Hassfurt GmBH and, also on that occasion, the OTH in Amber- Weiden through its Institute of Energy Technology. The R&D activities then continued with the subsequent Project CH2P, a scientific-technical research initiative funded by the Federal Ministry for Economic Affairs and Climate Protection. The stated aim was to increase the power density of hydrogen generators. The expertise gained from the subsequent installation of other plants undoubtedly proved decisive, not least in facilitating the conversion process of the Amberg-Weiden gas-fired combined heat and power plant. As tricolour chief executive officer Christian Manca himself pointed out, one of the knots to be unravelled, when it comes to hydrogen, remains that of storage.
A bridge between Italy and Germany
This is also being worked on in Amberg, through the development of a dedicated complementary plant. That operations of this tenor and development plans aimed at industry could also take off in our peninsula is suggested by Manca, who emphasised 2G’s commitment in several regions and segments – from the horeca to education and from waste treatment to healthcare – with traditional cogeneration. But there were also other events that recently came to a close: in Germany, the parent company hosted associates from the Hydrogen JRP project (an acronym for Joint research platform) to present the hydrogen cogenerator at Stadtwerk Haßfurt. The mission was attended by some lecturers from the Milan Polytechnic, who, together with the Milan Polytechnic Foundation and some industrial partners, are the promoters and founders of the platform. The goal is to stimulate the most innovative studies and research in the field of clean (i.e., green and low carbon) hydrogen production and novel solutions for transport and related advanced storage systems; electrochemical and thermal uses in cutting-edge residential, industrial and transport applications; and the development of best practices for the design and construction of infrastructures for hydrogen transport and storage.
Cogeneration from the front page
German publisher and printer Axel Springer SE is among the users of the g-box 50 cogeneration system from 2G Energy AG, in the broader context of its commitment to resource efficiency and environmental sustainability. The solution was installed following a thorough analysis phase that began in 2012 at the Kettwig offset printing plant in Essen, North Rhine-Westphalia. It boasts an electrical output of 50 kilowatts and a thermal output of 100 kilowatts, and is a truly clean technology for the combined production of heat and power, requiring 40% less primary energy than conventional plants. It is equipped with a catalytic converter and converter that contributes to a further reduction in harmful emissions; and it is also used as a heating support.