# How a Special Reactor Makes Methane Fuel Without Constant Electricity > This patent describes a method for a Solid Oxide Electrolyser Cell (SOEC) reactor to produce methane, even when electricity is scarce, by switching from electrolysis to a heat-generating chemical reaction. - **Patent:** US 10145018 - **Original title:** Method for operating an SOEC-type stack reactor for producing methane in the absence of available electricity - **Owner:** Commissariat a lEnergie Atomique et aux Energies Alternatives CEA - **Granted:** 2018 - **Status:** Active - **Times cited:** 0 - **Field:** energy, chemical_manufacturing, materials, telecommunications ## What it does This patent details a two-step process for operating a Solid Oxide Electrolyser Cell (SOEC) stack reactor, where the cathodes are made of catalytic material. First, when electricity is available (step a/ of claim 1), the reactor performs high-temperature electrolysis, splitting steam or a mix of steam and carbon dioxide to produce hydrogen or a mix of hydrogen and carbon monoxide. Second, when the electricity supply becomes insufficient for electrolysis (step b/ of claim 1), the reactor switches modes. It is then supplied with a mixture of hydrogen and carbon monoxide (synthesis gas) or hydrogen and carbon dioxide. This mixture undergoes a methanation reaction at the same cathodes, producing methane. This methanation reaction is exothermic, meaning it releases heat, which helps keep the reactor at its operating temperature without needing continuous electricity. For example, a reactor powered by solar panels could produce hydrogen during the day and then use that hydrogen to make methane at night, keeping itself warm. ## What it does NOT cover - Does not cover methanation processes that do not occur within an SOEC-type stack reactor where the cathodes are specifically made of methanation catalyst material(s). - Does not cover systems where the reactor is only used for electrolysis or only for methanation, without the ability to switch between these two modes based on electricity availability. - Does not cover methanation reactions that are not performed by 'heterogeneous catalysis' at the cathode. - Does not cover producing methane when electricity is fully available for electrolysis, as the patent specifically addresses operating when the electric current is 'insufficient' for electrolysis. - Does not cover reactors that lack the specific arrangement of electrical and fluid interconnectors between adjacent elemental cells as described in claim 1. ## The clever bit The core innovation is using the *same* SOEC reactor, with its catalyst-embedded cathodes, to perform *both* high-temperature electrolysis (when electricity is available) and exothermic methanation (when electricity is not), using the heat from the methanation reaction to keep the reactor at operating temperature. ## Real-world examples 1. Power-to-gas energy storage systems 2. Synthetic natural gas production from renewable electricity 3. Industrial processes for carbon dioxide utilization 4. Chemical energy storage for grid balancing ## Why it matters This patent addresses a significant challenge in renewable energy: its intermittent nature. By allowing a single reactor to both produce hydrogen/syngas when electricity is abundant and then convert it to methane when electricity is scarce, it offers a way to store excess renewable energy in a chemical form. Methane is easier to store and transport than hydrogen and can be integrated into existing gas infrastructure, making renewable energy more reliable and usable on demand. ## Frequently asked questions ### What does How a Special Reactor Makes Methane Fuel Without Constant Electricity cover? This patent describes a method for a Solid Oxide Electrolyser Cell (SOEC) reactor to produce methane, even when electricity is scarce, by switching from electrolysis to a heat-generating chemical reaction. ### Who owns patent US 10145018? Commissariat a lEnergie Atomique et aux Energies Alternatives CEA owns this patent, granted in 2018. ### When does this patent expire? This patent is expected to expire on November 19, 2034, when the invention enters the public domain. ### What problem does this patent solve? This patent addresses a significant challenge in renewable energy: its intermittent nature. By allowing a single reactor to both produce hydrogen/syngas when electricity is abundant and then convert it to methane when electricity is scarce, it offers a way to store excess renewable energy in a chemical form. Methane is easier to store and transport than hydrogen and can be integrated into existing gas infrastructure, making renewable energy more reliable and usable on demand. ### What does this patent NOT cover? Does not cover methanation processes that do not occur within an SOEC-type stack reactor where the cathodes are specifically made of methanation catalyst material(s). **Full plain-English explainer:** https://patentbrief.org/patent/us/10145018/method-for-operating-an-soec-type-stack-reactor-for-producing-methane-in-the-abs **Original patent:** https://patents.google.com/patent/US10145018 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [Making Chemicals from Carbon Dioxide and Steam Using Electricity](https://patentbrief.org/patent/us/20110132770/process-for-producing-compounds-of-the-cxhyoz-type-by-reduction-of-carbon-dioxid) — This patent describes a process that uses electricity to split steam and then reacts the resulting hydrogen with carbon dioxide or carbon monoxide to create various carbon-based compounds, like fuels or plastics. - [How to Make Hydrogen Gas Using Sulfur Dioxide and Electricity](https://patentbrief.org/patent/us/20090045073/electrolysis-cell-comprising-sulfur-dioxide-depolarized-anode-and-method-of-usin) — This patent describes a special kind of electrolysis cell that uses sulfur dioxide gas at one electrode to help produce hydrogen gas more efficiently. - [Making Hydrogen Gas from Sulfur Dioxide and Water at Low Temperatures](https://patentbrief.org/patent/us/9574276/production-of-low-temperature-electrolytic-hydrogen) — This patent describes a method for producing hydrogen gas using an electrochemical cell that reacts gaseous sulfur dioxide and water at a relatively low temperature, generating protons that become hydrogen. - [How to Make Hydrogen Gas and Cupric Chloride Using an Electrolysis Cell](https://patentbrief.org/patent/us/8636880/electrolysis-cell-for-the-conversion-of-cuprous-chloride-in-hydrochloric-acid-to) — This patent describes an electrochemical cell that uses cuprous chloride in hydrochloric acid to produce hydrogen gas and cupric chloride, separated by a special membrane. - [How to Make Big Electrodes for Splitting Water](https://patentbrief.org/patent/us/20210123152/method-for-preparing-large-area-catalyst-electrode) — This patent describes a simple, energy-saving way to create large, efficient catalyst electrodes using a mix of iron, cobalt, and nickel compounds through an electrical plating process.