# Making Hydrogen Gas from Sulfur Dioxide and Water at Low Temperatures > 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. - **Patent:** US 9574276 - **Original title:** Production of low temperature electrolytic hydrogen - **Owner:** University of South Carolina - **Granted:** 2017 - **Status:** Active - **Times cited:** 2 - **Field:** energy, chemical_manufacturing, sustainable_technology, materials ## What it does This patent details a process for making hydrogen gas using an electrochemical cell. The cell has an anode, a cathode, and a membrane separating them. A voltage is applied across the anode and cathode. Gaseous sulfur dioxide (SO2) is fed to the anode, and water (H2O) is fed to the cathode. A portion of the water travels through the membrane to the anode. At the anode, the SO2 reacts with the H2O in the gas phase, with the H2O being the limiting reactant, to produce sulfuric acid (H2SO4) and hydrogen protons (H+). These protons then pass through the membrane to the cathode, where they are reduced to form hydrogen gas. For instance, this process could be used to convert sulfur dioxide, a common industrial emission, into valuable hydrogen fuel. ## What it does NOT cover - Does not cover hydrogen production methods that do not use an electrochemical cell with a membrane separating the anode and cathode. - Does not cover processes where gaseous sulfur dioxide (SO2) is not fed to the anode as a reactant. - Does not cover hydrogen production where water (H2O) is not the limiting reactant in the anode reaction. - Does not cover methods where the specific reaction SO2 + 2H2O → H2SO4 + 2H+ + 2e− does not occur at the anode. - Does not cover high-temperature hydrogen production, as the claims specify operation at 80° Celsius or below. ## The clever bit The novelty lies in the specific electrochemical reaction at the anode, where gaseous sulfur dioxide reacts with water (which is the limiting reactant) to efficiently produce protons for hydrogen generation, all while operating at a comparatively low temperature. ## Real-world examples 1. Industrial hydrogen production 2. Fuel cell applications 3. Chemical manufacturing processes requiring hydrogen 4. Energy storage systems ## Why it matters Hydrogen is a clean energy carrier, and finding efficient, low-cost ways to produce it is crucial for a sustainable future. This patent focuses on a method that operates at a relatively low temperature (around 80° Celsius, as per claim 3), which could reduce the energy input and cost compared to high-temperature electrolysis methods. This could make hydrogen production more economically viable for various industrial and energy applications. ## Frequently asked questions ### What does Making Hydrogen Gas from Sulfur Dioxide and Water at Low Temperatures cover? 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. ### Who owns patent US 9574276? University of South Carolina owns this patent, granted in 2017. ### When does this patent expire? This patent is expected to expire on May 12, 2035, when the invention enters the public domain. ### What is patent US 9574276 cited by? This patent has been cited by 2 later patents that build on its ideas. ### What problem does this patent solve? Hydrogen is a clean energy carrier, and finding efficient, low-cost ways to produce it is crucial for a sustainable future. This patent focuses on a method that operates at a relatively low temperature (around 80° Celsius, as per claim 3), which could reduce the energy input and cost compared to high-temperature electrolysis methods. This could make hydrogen production more economically viable for various industrial and energy applications. ### What does this patent NOT cover? Does not cover hydrogen production methods that do not use an electrochemical cell with a membrane separating the anode and cathode. **Full plain-English explainer:** https://patentbrief.org/patent/us/9574276/production-of-low-temperature-electrolytic-hydrogen **Original patent:** https://patents.google.com/patent/US9574276 --- _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: - [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. - [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. - [Dome-Shaped Plates for Efficient Hydrogen Production in Electrolyzers](https://patentbrief.org/patent/us/20250027216/electrolyzer) — This patent describes an electrolyzer that uses uniquely dome-shaped plates to improve how water is split into hydrogen and oxygen, enhancing efficiency and product separation. - [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 a Special Reactor Makes Methane Fuel Without Constant Electricity](https://patentbrief.org/patent/us/10145018/method-for-operating-an-soec-type-stack-reactor-for-producing-methane-in-the-abs) — 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.