(21a) Industrial Perspectives in H2 Generation through Short Contact Time - Catalytic Partial Oxidation Technologies

Two research groups in the US (1) and in India (2) reported in 1992, findings showing that the catalytic partial oxidation (CPO) of methane for producing synthesis gas was promoted by reducing the contact time condition at values below few milliseconds. These findings were also under examination in industrial environments (3-4). It was since then discovered that the fast catalytic reactions occurred onto an incandescent solid-gas inter-phase zone; at temperatures that were higher than the equilibrium adiabatic temperatures and higher than the gaseous phase temperatures (5) . This physical chemistry condition was a consequence of a combination between very fast chemical reactions and heat and mass transfer limitations (6) . We also experimented the short contact time CPO (SCT-CPO) continuously since 1992 to nowadays with an industrial perspective perceiving the high potential of the innovation and utilising high pressure reactors (7) experimented at the pilot and the demonstrative scales. The SCT-CPO reactors were also designed and operated for utilising various reactants including some relatively heavy hydrocarbons containing S and aromatic compounds. In this case the high surface catalyst temperatures prevented the poisoning effects of S. These unique characteristics have been extensively examined both theoretically and experimentally and have originated the footsteps of three main production technologies named:

Technology 1 ? Air Blown SCT-CPO of gaseous hydrocarbons

Technology 2 ? Oxygen Blown SCT-CPO of gaseous hydrocarbons

Technology 3 ? Oxygen blown SCT-CPO of liquid hydrocarbons

In this presentation we will discuss their principles, the achievements and the foreseen perspectives. The discussion will be focused on H2 production for Oil up-grading and for other refinery applications and for the Fischer-Tropsch synthesis. However hints will also given concerning issues related to ammonia and methanol synthesis, formic and acetic acid production, reduction of iron ores and distributed H2 sources.

References

(1) H. Hickman and L.D. Schmidt, J.Catal. 267(1992), p.138

(2) V.R. Choudary, A.S. Hamman and S.D. Sansare, Angew.Chem.Int.Ed.Engl. 31(1992), p.1189

(3) K.A. Vonkeman, L.L.G. Jacobs, EP0576096

(4) L. Basini, D. Sanfilippo, M. Marchionna, US 5,856,585

(5) L. Basini, Catal.Today 117(2006), pp. 384 -393

(6) M. Bizzi, L. Basini, G. Saracco and V. Specchia, Ind. Eng.Chem.Res. 42(2003), pp. 62?71

(7) L. Basini, K. Aasberg-Petersen, A. Guarinoni and M. stberg, Catal.Today 64(2001), pp. 9?20