On demand hydrogen from methanol
A reactor system and a process for carrying out the methanol cracking reaction of a feedstock comprising methanol to hydrogen are provided, where the heat for the endothermic methanol cracking reaction is provided by resistance heating.
1. A reactor system for production of hydrogen from a feedstock comprising methanol in the presence of a catalyst under methanol cracking reaction conditions, said reactor system comprising:
a supply of feedstock comprising methanol and water;
a structured catalyst arranged for catalyzing said methanol cracking reaction of said feedstock, said structured catalyst comprising a macroscopic structure of an electrically conductive material, said macroscopic structure supporting a ceramic coating, wherein said ceramic coating supports a catalytically active material;
a pressure shell housing said structured catalyst, said pressure shell comprising an inlet for letting in said feedstock and an outlet for letting out product gas, wherein said inlet is positioned so that said feedstock enters said structured catalyst in a first end of said structured catalyst and said product gas exits said structured catalyst from a second end of said structured catalyst;
a heat insulation layer between said structured catalyst and said pressure shell;
at least two conductors electrically connected to said structured catalyst and to an electrical power supply placed outside said pressure shell, wherein said electrical power supply is dimensioned to heat at least part of said structured catalyst to a temperature of at least 150° C. by passing an electrical current through said macroscopic structure;
an outlet for a product stream comprising hydrogen.
2. The reactor system according to claim 1 , wherein said at least two conductors are connected to the structured catalyst at a position on the structured catalyst closer to said first end of said structured catalyst than to said second end of said structured catalyst, and wherein the structured catalyst is constructed to direct an electrical current to run from one conductor substantially to the second end of the structured catalyst and return to a second of said at least two conductors.
3. The reactor system according to claim 1 , wherein said electrical power supply is dimensioned to heat at least part of said structured catalyst to a temperature of at least 300° C.
4. The reactor system according to claim 1 , wherein the feedstock additionally comprises H 2 , N 2 , or Ar.
5. The reactor system according to claim 1 , wherein the pressure shell has a design pressure of between 2 and 30 bar.
6. The reactor system according to claim 1 , wherein the pressure shell has a design pressure of between 30 and 200 bar.
7. The reactor system according to claim 1 , further comprising electrically insulating parts provided in the structured catalyst and positioned between the at least two conductors.
8. A process for carrying out the methanol cracking reaction of a feedstock comprising methanol and water to hydrogen in the presence of a catalyst under methanol cracking reaction conditions, in a reactor system comprising a pressure shell housing a structured catalyst arranged for catalyzing said methanol cracking reaction of a feedstock, said structured catalyst comprising a macroscopic structure of electrically conductive material, said macroscopic structure supporting a ceramic coating, wherein said ceramic coating supports a catalytically active material; wherein said reactor system is provided with heat insulation between said structured catalyst and said pressure shell; said process comprising the steps of:
pressurizing said feedstock,
supplying said pressurized feedstock to said pressure shell through an inlet positioned so that said feedstock enters said structured catalyst in a first end of said structured catalyst; allowing the feedstock to undergo an methanol cracking reaction over the structured catalyst and outletting a product gas from said pressure shell, wherein said product gas exits said structured catalyst from a second end of said structured catalyst;
supplying electrical power via electrical conductors connecting an electrical power supply placed outside said pressure shell to said structured catalyst, allowing an electrical current to run through said macroscopic structure, thereby heating at least part of the structured catalyst to a temperature of at least 150° C.
outletting a product gas comprising hydrogen from the reactor system.
9. The process according to claim 8 , wherein the process further comprises the step of feeding the product stream comprising hydrogen to an upgrading unit and separating it into an upgraded hydrogen stream and an off-gas stream.
10. The process according to claim 9 , wherein the process further comprises the step of feeding the product gas or upgraded hydrogen stream from said upgrading unit to a downstream plant for electricity production.
11. A method for rapidly switching a metal-catalysed methanol cracking reaction of a feedstock comprising methanol in a reactor system according to claim 1 , from a first steady-state reaction condition (A) to a second steady-state reaction condition (B) or vice-versa; said method comprising the steps of:
in said first steady-state reaction condition (A):
supplying said feedstock to the reactor system in a first total flow, and
supplying a first electrical power via electrical conductors connecting an electrical power supply placed outside said pressure shell to said structured catalyst, thereby allowing a first electrical current to run through said electrically conductive material, thereby heating at least part of the structured catalyst to a first temperature at which said feedstock is converted to a first product gas mixture over said structured catalyst under said first steady-state reaction conditions (A); and said first product gas is outlet from the reactor system;
and, in said second steady-state reaction condition (B):
supplying said feedstock to the reactor system in a second total flow,
supplying a second electrical power via electrical conductors connecting an electrical power supply placed outside said pressure shell to said structured catalyst, thereby allowing a second electrical current to run through said electrically conductive material, thereby heating at least part of the structured catalyst to a second temperature; at which said feedstock is converted to a second product gas mixture over said structured catalyst under said second steady-state reaction conditions (B); and said second product gas is outlet from the reactor system;
wherein said second electrical power is higher than said first electrical power;
and/or said second total flow is higher than said first total flow.