# US 10,870,811 B2 · Method for operating fuel gas manufacturing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,811 B2 - Document ID: US10870811B2 - Status: Granted - Kind: B2 - Application number: 16/494,406 - Filed: 2018-03-23 - Published: 2020-02-13 - Granted: 2020-12-22 - Earliest claimed: 2017-03-23 - Assignees: Osaka Gas Co., Ltd. - Applicants: Osaka Gas Co., Ltd. - Inventors: Hidaka Asonuma; Tsubasa Shimizu; Takaya Kanda - Web page: https://patentgrep.com/patent/US10870811B2 ## CPC - C10L 3/08: Production of synthetic natural gas - C10L 3/12: Liquefied petroleum gas {(liquefying by pressure and cold treatment F25J)} - B01D 53/26: Drying gases or vapours - C10L 3/103: {Sulfur containing contaminants} - C10L 3/106: {of water} - C10L 2290/06: Heat exchange, direct or indirect - C10L 2290/08: Drying or removing water - C10L 2290/10: Recycling of a stream within the process or apparatus to reuse elsewhere therein - C10L 2290/148: of steam - C10L 2290/54: Specific separation steps for separating fractions, components or impurities during preparation or upgrading of a fuel - C10L 2290/542: Adsorption of impurities during preparation or upgrading of a fuel - C10L 2290/58: Control or regulation of the fuel preparation of upgrading process - C10L 2290/60: Measuring or analysing fractions, components or impurities or process conditions during preparation or upgrading of a fuel - Y02E 60/50: Fuel cells - C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Provided is a method for operating a fuel gas manufacturing device for stopping the operation in such a manner that the operation can be immediately resumed, while keeping facilities from becoming complex. When stopping the operation while supply of source gas to a desulfurizing unit is stopped, after supply of source gas to the desulfurizing unit and discharge of fuel gas to the outside are stopped, a standby operation process is performed in which fuel gas is circulated by a circulation driving unit in such a manner that the whole amount of fuel gas passed through a moisture removing unit is circulated through a circulation gas path to return to the desulfurizing unit and the circulated fuel gas is heated by a heating unit to a set standby temperature to heat a reforming unit to a temperature that is equivalent to an operation temperature at which reforming is performed, and supply of water vapor is continued in a state where a supply amount of water vapor is at least an amount with which carbon deposition due to thermal decomposition of fuel gas can be prevented and is smaller than an amount that is supplied when reforming is performed. ## Claims ### Claim 1 A method for operating a fuel gas manufacturing device, wherein the fuel gas manufacturing device comprises: a desulfurizing unit configured to desulfurize a heavy hydrocarbon source gas to produce a desulfurized source gas, a reforming unit configured to reform the desulfurized source gas by using water vapor to produce fuel gas, wherein the fuel gas comprises methane as a main component, a fuel gas return path configured to return a portion of the fuel gas supplied from the reforming unit to the desulfurizing unit, a moisture removing unit configured to remove moisture contained in the fuel gas supplied from the reforming unit to produce a dry fuel gas, and a circulation driving unit configured to route the dry fuel gas upstream of the desulfurization unit; the method further comprises performing a standby operation comprising: a) closing the source gas valve and the product gas valve; b) routing the dry fuel gas in its entirety to a point upstream of the desulfurizing unit and after the source gas valve as a circulated fuel gas, c) heating the circulated fuel gas by a heating unit set to a standby temperature equivalent to a non-standby operation reforming temperature, and d) continuing to supply water from a water vapor supply unit situated between the desulfurizing unit and the reforming unit in an amount sufficient to prevent thermal decomposition of the fuel gas and subsequent carbon deposition, and wherein the amount of supplied water vapor is less than the amount in non-standby reforming. ### Claim 2 (depends on 1) The method for operating a fuel gas manufacturing device according to claim 1, wherein a first heating unit that heats the fuel gas to be returned from the reforming unit to the desulfurizing unit and a second heating unit that heats the fuel gas to be supplied from the desulfurizing unit to the reforming unit are each provided as the heating unit. ### Claim 3 (depends on 2) The method for operating a fuel gas manufacturing device according to claim 2, wherein heating by the first heating unit is controlled to maintain the set standby temperature based on a detection temperature that is detected by a first temperature sensor that detects a temperature of the fuel gas discharged from the desulfurizing unit, and heating by the second heating unit is controlled to maintain the set standby temperature based on a detection temperature that is detected by a second temperature sensor that detects a temperature of the fuel gas discharged from the reforming unit. ### Claim 4 (depends on 1) The method for operating a fuel gas manufacturing device according to claim 1, wherein the fuel gas is supplied from the reforming unit to a gas consuming unit that is installed in a ship.