Picture: DTI
Green methanol is considered an interesting option in heavy-duty transport and shipping, but in northern regions it often fails at cold start. The reason is physical: methanol vapors do not ignite reliably below 11 °C. The Danish companies Heatflow and DTI have now demonstrated, in a “Mission Booster” project funded by Innovation Fund Denmark, a compact, metal additively manufactured gas-to-gas heat exchanger that addresses starting issues.
“These engines run well in the summer, but in winter they just won’t start. This challenge has created a critical bottleneck for methanol adoption across Scandinavia and other cold-climate regions. Methanol vapours cannot ignite below 11°C, which means that a standard methanol engine is impossible to start up at colder ambient temperatures”, explains Simon Brudler, AM specialist and senior consultant at DTI.“The 3D-printed heat exchanger reduced size and weight significantly and, after heat treatment, increased heat transfer efficiency by around 50%, which was key to achieving compact integration”, says Paw V. Mortensen, CEO at Heatflow ApS.
The system combines a methanol burner that can operate down to −10 °C with a specially designed heat exchanger that preheats the intake air, bringing the engine up to starting temperature. Metal 3D printing was chosen because the original, conventionally manufactured assembly was too large for integration in the engine compartment.
“3D printing is needed to make the system compact enough to actually pack into an engine. It is mainly about form factor – achieving the same performance in a much smaller space”, says Simon Brudler.“The project demonstrated that additive manufacturing enables a significantly more compact gas-to-gas heat exchanger, suitable for engine integration”, says Paw Mortensen, CEO, Heatflow ApS.
“We demonstrated the suitability of AM heat exchangers for gas-to-gas applications, highlighting how this opens doors for similar applications across various industries where gas-phase heat exchange is critical”, says Ellen M.J. Hedegaard, AM business manager at DTI.
Design and manufacturing leverage internal geometries that are hardly feasible conventionally. These include gyroid-like structures that maximize surface area per volume and define the flow path. The final prototype was printed in aluminum to save mass while ensuring high thermal conductivity. DTI specialists for green energy systems conducted performance tests and confirmed suitability for cold-start conditions; according to Mortensen, the system showed valid results down to −20 °C.
“The collaboration with DTI was decisive. They combined design-for-AM expertise with practical testing, enabling us to move from concept to validated prototype in less than a year”, says Paw V. Mortsensen.“This solution removes a key barrier for methanol engines in cold regions. With proven performance at -20°C, it enables e-methanol to become a viable fuel in both heavy transport and shipping”, says Paw V. Mortensen.
“This represents an important step toward enabling green methanol operation in cold climates”, says Paw Mortensen, CEO, Heatflow ApS.
Beyond heavy-duty vehicles, maritime applications are coming into focus. For Heatflow, a robust proof of concept is in place; further funded development phases are being evaluated. Partner Alicon contributed system requirements and integration data. The project highlights how metal 3D printing can retrofit thermal management tasks in existing powertrains, expanding the operational limits of methanol-based propulsion systems in cold climates.
