©EWE/C3 Visual LabQuelle: Atron

By converting to hydrogen operation, combined heat and power plants can be operated in an environmentally and climate-friendly manner. ©A-TRON Combined Heat and Power Units GmbH

Adaptation of a CHP unit using additively manufactured components for future hydrogen operation

Combined heat and power plants (CHP) offer an efficient heating option, especially for medium-sized to large properties such as hotels, apartment buildings, care facilities or similar buildings. This is because, unlike central gas or coal-fired power plants, CHP units can use almost all of the heat energy generated for heating. Although this can achieve efficiencies of over 90 percent, the combustion of conventional fuels such as natural gas or diesel produces pollutants such asCO2 or particulate matter. In order to make operation climate-friendly, A-TRON Blockheizkraftwerke GmbH and the two institutes ITV and IPeG of Leibniz University want to enable the use of hydrogen in CHP units in a project funded by the state of Lower Saxony - in the long term and in a climate-friendly way.

A CHP unit offers a form of decentralized energy generation that is particularly suitable for medium-sized and large buildings. It has a combustion engine in which a fuel is burned. The resulting thermal energy can be used almost entirely for heating, allowing high efficiencies of over 90% to be achieved. However, since fossil fuels such as natural gas or diesel are generally used at present, the combustion process still produces pollutants that are harmful to the climate, such asCO2 or particulate matter. In order to be able to use this efficient technology in a climate- and environmentally friendly way in the future, the project partners A-TRON and the Institute for Technical Combustion (ITV) and the Institute for Product Development and Device Construction (IPeG) at Leibniz Universität Hannover are investigating how hydrogen can be used as a fuel in CHP units as part of the project "Adaptation of a CHP unit using additively manufactured components for future hydrogen operation". The focus is not only on the basic feasibility, but in particular on developing hydrogen CHP units that can be used in the long term.

Innovative approach to enable hydrogen operation

To this end, two goals are being pursued within the framework of the project: In the first sub-goal, the operation of a CHP with hydrogen is to be made possible in principle. "The first objective is to demonstrate the feasibility of hydrogen use in CHP units. Since this requires changes to the technology, the project will take a highly innovative approach that improves not only the combustion technology but also the thermal boundary conditions." Professor Dinkelacker, managing director of the ITV, explains the project's objectives.

Since hydrogen is very ignitable, the components used must not become too hot. The aim is therefore to retrofit the combustion engine with suitable components and parts that can be cooled well. Particularly critical here is the engine's cylinder head, which can have locally hot areas - increasing the risk of unintentional ignition. To achieve high efficiency, heat recovery from the exhaust gas must also be improved. The temperature of the exhaust gas is lower than in natural gas engines, which is why a heat exchanger is to be developed to transfer the heat efficiently to the heating circuit.

Quelle: Atron

©A-TRON Combined Heat and Power Plants Ltd.

Durability of the components is to be increased

In the second sub-goal, the durability of the hydrogen CHP units is also to be increased. Since not inconsiderable emissions are already produced during the manufacture of the CHP units, they should be used for as long as possible. To this end, the durability of the individual components must be increased - but especially that of the liner, whose service life is the most limited. Wear is to be countered in particular by additive manufacturing (3D printing) of modern components. In addition, wear will be made measurable during operation as part of the project. This can replace the cost-intensive removal of the entire engine, which is currently still necessary for wear measurement (and liner replacement). In addition, more efficient thermal management is made possible.

Professor Lachmayer, managing director of IPeG, emphasizes the importance of the project for a successful heat transition: "Both hydrogen combustion in CHP units and the integration of additive manufacturing into engine technology are novel. If CHP units can be operated with hydrogen without greenhouse gas emissions, this is a central building block for the heat turnaround."

State of Lower Saxony supports the project

The project partners include A-TRON Blockheizkraftwerke GmbH as well as the Institute for Technical Combustion and the Institute for Product Development and Device Construction, two institutes of Leibniz Universität Hannover. The project is being funded by the state of Lower Saxony with just under €800,000 and is scheduled to run until October 2024.

"As a ministry, we expressly support the project. After all, we need to explore what effective ways there are of converting hydrogen back into electricity and how the heat generated in the process can be used. We also want to get away from fossil fuels as quickly as possible. Hydrogen offers many possibilities for this, and we are also intensively pursuing this in pilot and demonstration projects."

Christian Meyer, Lower Saxony Minister for Energy and Climate Protection

While the institutes of Leibniz Universität Hannover want to transfer the knowledge gained to other fields of research following the project, A-TRON GmbH plans to use the new CHP units to supply its current customer base and open up other markets. In this context, Daniel Steck, head of development at A-TRON Blockheizkraftwerke GmbH, emphasizes the opportunities that arise when the hydrogen economy takes off: "Currently, we are already selling environmentally friendly CHP units - e.g. in the form of biogas or sewage gas plants. With this project, however, we want to strategically expand our portfolio. By successfully adapting a CHP to run on hydrogen, we can invest in an important future market and contribute to the development of a greenhouse gas-neutral hydrogen infrastructure."


©Ahrens Roof Technology
©DLR Institute for Networked Energy Systems
©DLR Institute for Networked Energy Systems

The A-TRON Combined Heat and Power Plants Ltd. is an internationally active developer and manufacturer of mini CHP units. Environmentally friendly CHP units are already being sold in the form of biogas or sewage gas plants - the hydrogen CHP unit adds another climate-friendly offering. 

Logo: © A-TRON Combined Heat and Power Plants Ltd.



At the Institute for Product Development and Device Engineering (IPeG), the topics the topics of development methodology, systems engineering, additive manufacturing and optomechatronics are dealt with. The institute realizes integrated product development from the idea to the prototype in their workshops and laboratories.

Logo: © Institute for Product Development & Device Engineering

The Institute for Technical Combustion (ITV) conducts research and teaches in the areas of turbulent combustion, spray injection processes, diesel and gas engine combustion processes, and engine tribology. New topics are "sustainable combustion". 

Logo: © Institute for Technical Combustion