April 2021

30 | Plant & Works Engineering www.pwemag.co.uk April 2021 Energy & Environmental Management Focus on: Boilers, Burners & Controls H2 combustion technology is ready for the market I n the public debate, hydrogen (H2) has advanced to become the energy carrier of the future, because its potential availability, especially in those industries that are difficult to decarbonise, is enormous. The same also applies to heat supply, although at present it is mainly H2 from manufacturing processes that is used. A practical example at the specialty chemicals company Nouryon shows which technological hurdles have to be considered: To provide this cost-efficient, safe and low-emission use of the fuel requires specific combustion know-how. The goal is ambitious: To become a climate- neutral continent by 2050. The production of green hydrogen from renewable energies is expected to increase to one million tons by 2024 and to ten million tons by 2030. The infrastructure for transport and storage is already in place - up to 20% vol. H2 could be added to the UK natural gas grid in the future and these pipelines could thus be gradually converted. Infact, this figure of up to 20% is being looked at currently by a HyDeploy project hosted at Keele University. Whilst this initiative is a great step forward, to meet the 2050 target, 100% H2 needs to be looked at. Currently, however, even the capacities permitted up to 10% vol. remain unused because not enough hydrogen is produced. In industrial heat generation, fossil fuels are often even cheaper or biofuels such as wood dust are an alternative. At present in the UK, there are several companies planning to use redundant energy from wind turbines for H2 generation, meaning the generation of energy from renewable forms will be maximised in the near future increasing utilisation and balancing the mix of the various types of H2 produced (grey or green) and also reducing the cost of the H2 production. The political will for a climate-neutral hydrogen revolution is rapidly gaining momentum. This is because hydrogen is eminently suitable for thermal utilisation: In terms of fuel quality (Wobbe index) it is on a par with H2 combustion technology is ready for the market and offers a wide range of advantages - but there are some engineering challenges to overcome. PWE reports. natural gas. Its calorific value, which is three times lower, is offset by its significantly lower density. Flame monitoring is also easily possible with existing standard UV flame sensors. However, despite all the potential in the use of H2 in heating processes, there are also a number of challenges to overcome. As shown below, smart combustion technology can contribute to efficient, safe and comparatively environmentally friendly operation as a piece of the mosaic - and not only as soon as the natural gas pipelines have been converted to hydrogen on a large scale, but also today for very specific applications. Thermal utilisation of hydrogen as a waste product The globally active company Nouryon was formed in 2018 from the chemicals division of the AkzoNobel Group and produces chemicals for everyday products. Max Krausnick, development engineer at SAACKE GmbH, explained that with the help of SAACKE, specialising in thermal processes and plants in the industrial and maritime energy management sector, the company has been converting its processes to H2 compatibility since the 1990s. This is because hydrogen is also produced as a main and surplus by- product in the chlor-alkali electrolysis process at the European market leader for industrial salt, chlorine trading and chloromethanes. With plant upgrades such as the most recent one in 2019, these existing residual materials can be used as a valuable substitute and fed back to the heat demand of the electrolysis process instead of purchasing costly natural gas as the primary fuel. In this way, the operators - Nouryon operates the electrolysis in a joint venture with Evonik - not only anticipate legal regulations, but also use existing synergies and save 577 m3 of natural gas (H) per hour. This is made possible by three hydrogen burners of the SKVGD type, which are based on rotary atomiser technology and are flexibly suitable for liquid and gaseous special fuels. In Ibbenbüren, they are installed with a maximum output of 4.3 to 7.6 MW (depending on the One of the three SAACKE SKVGD hydrogen burners in use at the specialty chemicals company Nouryon in Ibbenbüren.