EP-4741337-A1 - AMMONIA-HYDROGEN MIXED FUEL PRODUCTION APPARATUS, FUEL SUPPLY SYSTEM, AND HYDROGEN PRODUCTION METHOD

EP4741337A1EP 4741337 A1EP4741337 A1EP 4741337A1EP-4741337-A1

Abstract

[Problem] Provided are an ammonia-hydrogen mixed fuel production apparatus and a fuel supply system, which are capable of stably acquiring hydrogen from ammonia even when a required ratio of a fuel is changed. [Solution] An ammonia-hydrogen mixed fuel production apparatus 1010A includes an oxygen separator 13 that separates oxygen (O 2 ) 12 from air 11 at a desired concentration, a reforming reactor 15 that converts ammonia (NH 3 ) supplied from a raw material supply portion 14 into hydrogen (H 2 ) by using the oxygen of the desired concentration from the oxygen separator 13, and a gas component analyzer 17 that measures a concentration of one or both of the hydrogen and the ammonia in a reformed gas 16 from the reforming reactor 15.

Inventors

MORI, YOH
OKEYA, HISASHI
INOMATA, MAKOTO
YUMURA, TAKUO
WANG, YUFEI

Assignees

Mitsubishi Kakoki Kaisha, Ltd

Dates

Publication Date: 20260513
Application Date: 20240719

Claims (13)

An ammonia-hydrogen mixed fuel production apparatus, comprising: an oxygen supply portion configured to supply oxygen of a desired concentration; a reforming reactor configured to convert ammonia into hydrogen by using the oxygen of the desired concentration supplied from the oxygen supply portion, and to use an acquired mixture as a reformed gas; and a gas component analyzer configured to measure a concentration of one or both of the hydrogen and the ammonia in the reformed gas from the reforming reactor.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1, wherein the oxygen supply portion is an oxygen separator that separates oxygen from air at a desired concentration.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1, wherein the oxygen supply portion is an air dryer that removes moisture in supplied air.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1, wherein the oxygen supply portion adds 3 vol% to 20 vol% of oxygen with respect to a supply amount of the ammonia.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1 or 2, wherein a supply amount of the oxygen from the oxygen supply portion is controlled based on the concentration of one or both of the hydrogen and the ammonia from the gas component analyzer.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1 or 2, wherein a bypass line for supplying the ammonia from the raw material supply portion is provided between the reforming reactor and a measurement point of the gas component analyzer on a downstream side of the reforming reactor.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1 or 2, further comprising: a bypass line configured to supply the ammonia from a raw material supply portion between the reforming reactor and a measurement point of the gas component analyzer on a downstream side of the reforming reactor; and a storage tank provided between an ammonia introduction position of the bypass line and the reforming reactor, in which a gas composition of the reformed gas and the ammonia is adjusted according to a composition ratio of the ammonia and the hydrogen in the gas component analyzer and a required fuel composition ratio.
The ammonia-hydrogen mixed fuel production apparatus according to claim 1, wherein the reforming reactor includes: a housing that includes an introduction port through which the ammonia and a combustible gas other than the ammonia are introduced, and an outlet port through which a produced gas flows out, a first catalyst portion disposed inside the housing and including a first catalyst that generates heat by combusting the combustible gas introduced from the introduction port, and a second catalyst portion disposed between the first catalyst portion and the outlet port and including a second catalyst that is heated by the heat generated in the first catalyst portion and generates hydrogen from ammonia.
The ammonia-hydrogen mixed fuel production apparatus according to claim 8, wherein the first catalyst portion is disposed between the introduction port and the second catalyst portion.
The ammonia-hydrogen mixed fuel production apparatus according to claim 8, wherein the reactor includes, between the first catalyst portion and the second catalyst portion, a dispersion portion that disperses a gas flowing out from the first catalyst portion toward the second catalyst portion.
The ammonia-hydrogen mixed fuel production apparatus according to claim 8, further comprising: an outflow channel through which the hydrogen flows out from the outlet port; a tank provided in the outflow channel and configured to store the hydrogen flowing out; and a return channel branched from a branch portion of the outflow channel and configured to return the hydrogen to the introduction port.
A fuel supply system using an ammonia-hydrogen mixed fuel production apparatus according to claim 1 or 2 to supply an ammonia-reformed fuel to a fuel demand portion side.
A hydrogen production method, comprising: an introduction step of introducing an introduction gas containing ammonia and a combustible gas other than the ammonia into a reactor; a combustion step of selectively combusting the combustible gas in the introduced introduction gas with a first catalyst; a second catalyst heating step of heating a second catalyst, which generates hydrogen from the ammonia, by heat generated in the combustion step; and a reforming step of stopping the introduction of the combustible gas after a temperature of the second catalyst reaches a predetermined temperature, and generating the hydrogen from the ammonia by using the second catalyst.

Description

TECHNICAL FIELD The present invention relates to an ammonia-hydrogen mixed fuel production apparatus, a fuel supply system, and a hydrogen production method. BACKGROUND ART In recent years, techniques for using ammonia to achieve carbon neutral have attracted attention. As an example of producing hydrogen (H2) from ammonia (NH3), there is an ammonia decomposition method (see Patent Literature 1). CITATION LIST NON-PATENT LITERATURE Patent Literature 1: JP2022-144912APatent Literature 2: JP2023-83706A SUMMARY OF INVENTION TECHNICAL PROBLEM However, in the proposal of the decomposition method of acquiring hydrogen from ammonia, which is disclosed in Patent Literature 1, it is necessary to use an ammonia decomposition device that heats from the outside of a reactor to supply heat. This ammonia decomposition device performing external heating uses a method of mixing air (oxygen) with a mixed gas of ammonia (NH3) and H2/N2 as an off-gas from a pressure swing adsorption (PSA) device and then combusting the mixed gas by using, for example, a burner or the like, but the ammonia as a main fuel has a lower combustion speed than a fuel such as methane, and has problems not only in reliable ignition and combustion stabilization but also in generation inhibition of a nitrogen oxide. However, a composition (a hydrogen/ammonia composition ratio) and a flow rate of the fuel may vary depending on requirements of a boiler, a gas engine, an industrial furnace, and the like on a downstream side. When such turndown is large (for example, a turndown ratio varies from 100% to 20%, and a hydrogen ratio varies from 100% to 20%), it is difficult to stably combust the fuel by the external heating or quickly cope with the variation at the time of converting the ammonia into the hydrogen in the ammonia decomposition device. Further, in an autothermal reformer (ATR) device that oxidatively decomposes ammonia, the ammonia is oxidized by oxygen in an oxidative decomposition catalyst portion. Due to self-heating by oxidation, the ammonia is subjected to oxidative decomposition and a decomposition reaction in the catalyst portion of the ATR device, and is reformed into hydrogen. . According to the technique described in Patent Literature 2 in the related art, ammonia as a raw material for ammonia reforming is oxidized on a catalyst. Therefore, it is necessary to heat the catalyst or a raw material gas in advance because the catalyst is not oxidized unless the catalyst is heated to 200°C or higher. In addition, in a small-to-medium-scale system capable of generating hydrogen of 100 m3 to 2,000 m3 per hour, which is an object of the present invention, it is necessary to quickly cope with a load variation and a daily start and stop (DSS) operation in order to produce a fuel to be used in a heating furnace, a gas engine, or a boiler in which the load variation is large and the DSS operation is frequently performed. Further, since the system has a small and medium scale, the size of a reactor is small, when heat dissipation from the reactor increases, it is necessary to increase an oxidation amount of the ammonia in order to compensate for heat required for the decomposition reaction of the ammonia, and as a result, the yield of the hydrogen and thermal efficiency decrease. In order to package the device, it is necessary to reduce the number of units and make the reactor compact. Further, when a boiler, an industrial furnace, or the like is used as a supply destination of the hydrogen, since the boiler, the industrial furnace, or the like frequently repeats turndown, shutdown, and startup, a self-supporting type boiler, industrial furnace, or the like that can easily and quickly cope with the above is desirable. In the case of a unit in the related art, since it is necessary to perform an operation of heating to 200°C or higher at which an oxidative decomposition reaction can be started at the time of startup, a heating facility needs to be separately provided, the facility is complicated, and it is difficult to provide quick countermeasures. In view of the above problems, the present invention provides an ammonia-hydrogen mixed fuel production apparatus, a fuel supply system, and a hydrogen production method, which are capable of stably and quickly acquiring hydrogen from ammonia even when a required composition ratio or an amount of a fuel is changed. SOLUTION TO PROBLEM (1) An ammonia-hydrogen mixed fuel production apparatus according to one aspect of the present invention includes: an oxygen supply portion configured to supply oxygen of a desired concentration;a reforming reactor configured to convert ammonia into hydrogen by using the oxygen of the desired concentration supplied from the oxygen supply portion, and use an acquired mixture as a reformed gas; anda gas component analyzer configured to measure a concentration of one or both of the hydrogen and the ammonia in the reformed gas from the reforming reactor.(2) In the ammonia-hydrogen