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US-12623902-B2 - Process for producing hydrogen

US12623902B2US 12623902 B2US12623902 B2US 12623902B2US-12623902-B2

Abstract

The present invention provides a process for producing hydrogen comprising exposing a liquid composition comprising a hydrocarbon to electromagnetic radiation in the presence of a solid catalyst, wherein the catalyst comprises: at least one metal species, comprising one or more elements selected from Fe, Ni and Co; and a non-oxygenated ceramic. Also provided are a heterogeneous mixture comprising a solid catalyst in intimate mixture with a liquid composition comprising a hydrocarbon wherein the catalyst comprises: at least one metal species comprising Fe and/or Ni; and a non-oxygenated ceramic. Also provided are the use of said mixture to produce hydrogen, a microwave reactor comprising said mixture and a vehicle comprising said reactor. Furthermore, the invention provides a fuel cell module comprising a (i) a fuel cell and (ii) a heterogeneous mixture as described herein, and a vehicle or electronic device comprising said fuel cell module.

Inventors

  • Tiancun Xiao
  • Peter P. Edwards
  • Xiangyu JIE

Assignees

  • OXFORD UNIVERSITY INNOVATION LIMITED

Dates

Publication Date
20260512
Application Date
20171204
Priority Date
20161205

Claims (14)

  1. 1 . A process for producing a gas comprising hydrogen, comprising exposing a liquid composition comprising a hydrocarbon to microwave radiation in the presence of a solid catalyst, wherein the catalyst comprises: a binary mixture of elemental metals selected from elemental Fe and elemental Ni (Fe/Ni), elemental Fe and elemental cobalt (Fe/Co), elemental Fe and elemental Ru (Fe/Ru), elemental Fe and elemental Cu (Fe/Cu), elemental Ni and elemental Co (Ni/Co), elemental Ni and elemental Ru (Ni/Ru); or elemental Ni and elemental Cu (Ni/Cu); and a non-oxygenated ceramic; wherein the gas produced comprises about 1 vol. % or less of carbon monoxide and about 1 vol. % or less of carbon dioxide in the total amount of evolved gas; and wherein the liquid composition comprises at least 75 wt. % of C 9 to C 20 hydrocarbons and is substantially free of water.
  2. 2 . A process according to claim 1 , wherein the binary mixture of elemental metals is selected from elemental Fe and elemental Ni (Fe/Ni).
  3. 3 . A process according to claim 1 , wherein the ratio the elemental metals is from about 10:1 to about 1:10.
  4. 4 . A process according to claim 1 , wherein the catalyst has a metal species loading of from about 2 wt. % to about 5 wt. %.
  5. 5 . A process according to claim 1 , wherein the non-oxygenated ceramic is a carbide or a nitride.
  6. 6 . A process according to claim 5 , wherein the non-oxygenated ceramic is selected from silicon carbide, boron carbide, tungsten carbide, zirconium carbide and aluminium carbide.
  7. 7 . A process according to claim 6 , wherein the non-oxygenated ceramic is selected from silicon carbide and silicon nitride.
  8. 8 . A process according to claim 1 , wherein the catalyst essentially consists of elemental Fe and elemental Ni supported on silicon carbide.
  9. 9 . A process according to claim 1 , wherein the liquid composition essentially consists of non-oxygenated petro-diesel or commercial petro-diesel.
  10. 10 . A process according to claim 1 , wherein a binary mixture of elemental metals selected from elemental Fe and elemental Ni (Fe/Ni) or elemental Fe and elemental cobalt (Fe/Co).
  11. 11 . A process according to claim 1 , wherein the binary mixture of elemental metals is selected from elemental Fe and elemental Co (Fe/Co).
  12. 12 . A process according to claim 1 , wherein the catalyst essentially consists of elemental Fe and elemental Co supported on silicon carbide.
  13. 13 . A process according to claim 1 , wherein the ratio the elemental metals is about 1:1.
  14. 14 . A process according to claim 1 , wherein the catalyst has a metal species loading of about 5 wt. %.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the National Stage of International Application No. PCT/GB2017/053645, filed Dec. 4, 2017, which claims the priority to GB 1620667.4, filed Dec. 5, 2016, which are entirely incorporated herein by reference. INTRODUCTION The present invention relates to a process for producing hydrogen from fossil fuels. In particular, the process of the present invention provides a catalytic process for the decomposition of hydrocarbons to provide high purity hydrogen gas, suitably with minimal carbon by-products (such as CO2, CO and small hydrocarbons). BACKGROUND OF THE INVENTION Today, the world's ever-increasing energy demand is still based almost exclusively on fossil fuels, not only because of their unrivalled energy-carrying properties but also because of the demands of the world-wide energy infrastructure which has developed over the past century. Hydrogen is regarded as one of the key energy solutions for the future (1-5), not only because of its intensive energy density per unit-mass, but also because its combustion produces no environmentally harmful carbon dioxide. Hence the problem of capturing this by-product is circumvented (1-5). However, the cost of hydrogen production, delivery, and storage systems is the major barrier that hinders the development of hydrogen-based economy (1, 6-12). The most efficient and widely used process so far for the production of hydrogen in industry is based on fossil fuel, for example by steam reforming or partial oxidation of methane and to a lesser degree by gasification of coal (3, 12-14). However, like combustion of hydrocarbons, all these conventional options of hydrogen production from hydrocarbons involve CO2 production, which is environmentally undesirable. Therefore, technologies like Carbon Capture and Storage (CCS) and Carbon Capture and Utilization (CCU) are needed to control the CO2 level (1,15). Solar energy can be used to yield increasing amounts of hydrogen by the splitting of water, but even if the photocatalytic or electrolytic breakdown of water could be greatly improved to produce large quantities of H2, the question of its safe storage and rapid release for immediate use in applications such as fuel cells, for example, would still be problematic (1, 12). There is a need for an in-situ process for the rapid release of high purity hydrogen from a suitable hydrogen containing material without the generation of environmentally harmful carbon dioxide. Such technologies would accelerate the introduction of widespread use of hydrogen powered vehicles for instance, thus reducing pollution and aiding the environment. A recent development has seen the use of wax as a benign-hydrogen storage material to rapidly release hydrogen-rich gases through a microwave assisted catalytic decomposition (16). The present invention seeks to provide a simple and compact technology for in-situ hydrogen generation from a suitable hydrogen containing material. The present invention aims to provide high purity hydrogen with minimal production of carbon dioxide. SUMMARY OF THE INVENTION The present invention provides a simple and compact process for the production of hydrogen from liquid hydrocarbons using the assistance of electromagnetic radiation. This allows the production of highly pure hydrogen with minimal carbon by-products (such as CO2, CO and small hydrocarbons). This technology has particular application to in situ hydrogen generation, in particular on board hydrogen generation. Accordingly, in a first aspect the present invention provides a process for producing hydrogen comprising exposing a liquid composition comprising a hydrocarbon to electromagnetic radiation in the presence of a solid catalyst, wherein the catalyst comprises: at least one metal species, comprising one or more elements selected from Fe, Ni and Co; anda non-oxygenated ceramic. In a second aspect, the present invention provides a heterogeneous mixture comprising a solid catalyst in intimate mixture with a liquid composition comprising a hydrocarbon wherein the catalyst comprises: at least one metal species, comprising one or more elements selected from Fe, Ni and Co; anda non-oxygenated ceramic. In a third aspect, the present invention provides the use of a heterogeneous mixture of the second aspect for generating hydrogen. In a fourth aspect, the present invention provides a microwave reactor comprising a heterogeneous mixture, said mixture comprising a solid catalyst in intimate mixture with a liquid composition comprising a hydrocarbon wherein the catalyst comprises: at least one metal species, comprising one or more elements selected from Fe, Ni and Co; anda non-oxygenated ceramic. In a fifth aspect, the present invention provides a vehicle comprising a microwave reactor according to the fourth aspect. In a sixth aspect, the present invention provides a fuel cell module comprising (i) a fuel cell and (ii) a heterogeneous mixture comprising a sol