The HEX reactors technology developed by the LACRE is based on planar milli-structured reactors. They consist of layers of reactive channels which alternate with cross flow cooling or heating channels. The advantage of this architecture are a higher mass and heat transfers, more flexible, higher compactness and safer than adiabatic reactors and shell-and-tube reactors technologies. The concept of the reactors is characterized by reduced hydraulic diameter of reactive channels in a range from a few millimeters to centimeter. The concept ensures a good heat exchange and limiting hot spots and it promotes high conversion rates and an accurate control of the reaction temperature by the temperature of the mineral oil circulating in channels.
Principle of heat exchanger reactor
Methanation heat exchanger reactor of 0,8 Nm3/h of CH4
The manufacturing of HEX reactor is made by diffusion bonding. The assembling process is implemented by Hot Isostatic Pressure process. This technology allows to obtain assembling in solid state by combination of the application of high pressure and temperature for a controlled time on elements to be bonded. Pressure allows surfaces to be in contact and the removal of the residual porosity in the interfaces between the parts to be welded by diffusion creep. The high temperature allows to activate the atomic diffusion and growth of grains at the interface, allowing them to cross these interfaces.
The upscaling is done by numbering up modules at constant design. The figure depicts a methanation unit of a capacity of 20-40 Nm3/h of methane production by CO2 hydrogenation. This unit includes gas preheating, the methanation HEX reactors, the cooling system, the steam condensation and the control command. This unit could be integrated into a Power to Gas system from 400 to 800 kWe.
Example of methanation unit of 20-40Nm3/h of CH4