Overview:

The produc­tion of ammonia from rene­wable ener­gies is one of the main tasks of the CAMPFIRE alli­ance. The aim of this sub-project is to expand and opti­mize a reactor concept for the synthesis of ammonia. 

The power density of the Haber-Bosch reactor will be improved by hybri­di­zing two opera­ting approa­ches to further develop the exis­ting reactor concept based on flow control elements. The reactor with flow control elements deve­loped as part of the project CF06_1 will be further deve­loped into a hybrid packed-bed/­fixed-bed reactor with inte­grated active cooling and the active cata­lyst surface will be increased. Further­more the heat inte­gra­tion of the solid oxide elec­tro­lyzer is improved by an inno­va­tive approach. For cooling the reac­tants and thermal oils are used, which are also used in the available plants for steam gene­ra­tion for high-tempe­ra­ture elec­tro­lysis. In addi­tion, a scree­ning of cata­lysts for the new hybrid Haber-Bosch process is being carried out. 

These opti­miza­tions enable dynamic opera­tion of the Haber-Bosch reactor, which is neces­sary for opera­tion with rene­wable ener­gies. The func­tional model of the plant imple­mented in COIL will have an output of 200 kWel with a produc­tion rate of 3–5 kg H2. A control system for hybrid process manage­ment is being deve­loped for this purpose. The aim is also to develop a guide­line for the appr­oval of decen­tra­lized ammonia syntheses for energy storage and certi­fi­ca­tion of decar­bo­nized energy storage systems. 

Figures: Left — Sche­matic of a Haber-Bosch plant with reactor, gas sepa­ra­tion and cooler; Right — Depen­dence of the ammonia yield on the process window in the Haber-Bosch process.