Process for producing hydrogen from thermoplastic polymers with electromagnetic radiation
The present invention provides a process for (a) recycling plastic; and/or (b) producing hydrogen; and/or (c) producing syngas; and/or (d) producing carbon nanotubes, wherein the process comprises exposing a solid composition comprising one or more thermoplastic or thermosetting polymers to electromagnetic radiation in the presence of a solid catalyst, wherein the catalyst comprises elemental iron (Fe) or an oxide thereof. Also provided is a solid composition comprising a catalyst in intimate mixture with one or more thermoplastic or thermosetting polymers, wherein the catalyst comprises elemental iron (Fe) or an oxide thereof. Also provided is the use of said solid composition to produce hydrogen, syngas and/or carbon nanotubes, and a microwave reactor comprising said solid composition.
1. A process for producing hydrogen comprising exposing a solid composition comprising one or more thermoplastic polymers to electromagnetic radiation in the presence of a solid catalyst, wherein the solid catalyst comprises an iron oxide, alumina, and carbon, wherein iron is present in about 70 wt. % to about 95 wt. % of the solid catalyst, wherein the one or more thermoplastic polymers is/are polyethylene, polypropylene, or polystyrene, wherein the electromagnetic radiation is microwave radiation, and wherein the process produces about 70 vol. % or more of hydrogen in a total amount of evolved gas.
2. The process according to claim 1 wherein the iron oxide comprises ferric oxide (Fe 2 O 3 ).
3. The process according to claim 1 wherein the iron is present in about 90 wt. % to about 95 wt. % of the total weight of the catalyst.
4. The process according to claim 1 wherein the ratio of the iron to the alumina is about 1:1 to about 100:1.
5. The process according to claim 1 wherein the carbon is present between about 1 wt. % and about 10 wt. % of the total weight of the catalyst.
6. The process according to claim 1 wherein the catalyst comprises particles of the iron oxide which have a mean particle size of between 50 nm and 1 mm.
7. The process according to claim 1 wherein the solid composition comprises the one or more thermoplastic polymers and the catalyst in admixture.
8. The process according to claim 1 wherein the ratio of the polymer(s) to the catalyst is about 5:1 to about 1:5.
9. The process according to claim 1 wherein the solid composition is comprised of at least 40% (w/w) of the one or more thermoplastic polymers.