Aluminium-steam reaction in a swirled stabilized flame: a new way for decarbonized combined heat and hydrogen production

The present contribution aims to demonstrate experimentally the feasibility of continuous H 2 production through the Al–H 2 O reaction. The experiment involves stabilizing an aluminum-air flame with swirl flow in a combustion chamber, then injecting steam downstream of the flame. Aluminum powder (60 μm diameter) is fed at mass flow rate up to 3.25 kg/h, with an air flow of 7.7 (n)m 3 /h and a swirl number of 28. Steam is generated with an evaporator, reaching up to 6% H 2 O mole fraction. The global equivalence ratio ranges from 0.7 to 1.2. Oxygen, hydrogen and steam mole fractions at the chamber outlet are measured with on-line analyzers, while temperatures are characterized by thermocouples and a pyrometer. Results show complete consumption of injected oxygen and up to 100% conversion of steam into hydrogen, occurring via direct aluminum oxidation with H 2 O or through thermolysis of H 2 O followed by aluminum oxidation. • Aluminum is an efficient energy carrier releasing heat through combustion. • An aluminum-air flame with continuous steam injection successfully produced hydrogen. • Up to 100% conversion of injected steam into hydrogen is observed. • Direct oxidation of aluminum with water seems the main mechanism for hydrogen formation.