Process of hydrogen gas scrubbing from battery room exhaust gases

Abstract

The hydrogen removal scrubber utilises a catalyst bed and is a specialised system designed to efficiently remove hydrogen from a gas stream. The catalyst bed may be a hydrogen scavenger or hydrogen pu

Description

Inventor: Kantikumar Lakhankar 29, Wallacebrae Drive, Danestone Aberdeen, Scotland, United Kingdom AB22 8YA Company: Kapwell Ltd, Provender House, 37 Waterloo Quay, Aberdeen, Scotland, United Kingdom AB11 5BS The following specification particularly describes the invention Title: Process of Hydrogen Gas scrubbing from Battery Room Exhaust Gases Field of Invention:

[0001] This invention relates to exhaust gases produced from various types of batteries stored in enclosed room which contains hydrogen gas. Background to the invention:

[0002] Hydrogen gas is highly flammable, and its removal from battery room gases can significantly enhance safety. By reducing the presence of hydrogen, the risk of explosions, fires, and other accidents related to hydrogen gas is mitigated. The usage of the present invention can protect employees, equipment, and facilities, leading to a safer working environment.

[0003] Many industrial sectors have specific regulations and safety standards concerning hydrogen gas management. By effectively removing hydrogen gas from battery room gases, a company can ensure compliance with the specific regulations and safety standards. The implementation of the invention the process will help in avoiding potential fines, penalties, or legal issues that may arise from non-compliance of such regulation and safety standards.

[0004] The removal of hydrogen gas using the present invention from battery room gases can lead to improved safety, regulatory compliance, operational reliability, energy efficiency, environmental sustainability, and enhanced reputation. Object of Invention:

[0005] The present invention relates to removal and scrubbing of the hydrogen gas emission from enclosed battery room gases. This is important not only from economic perspective, but is also advantageous to minimize the risk of explosion hazard. This present invention relates to a process for efficiently separating hydrogen gas from battery room gases, specifically in the context of battery energy storage systems (BESS) and similar applications. Statement of Invention:

[0012] Process of Hydrogen Gas scrubbing from Battery Room Exhaust Gases provides most economical and environmentally friendly solution. Summary of Invention: [0013} The invention provides a catalyst bed-based Hydrogen removal plant to efficiently remove hydrogen from a gas stream. The catalyst bed, also known as hydrogen scavenger or hydrogen purifier, is a key component in this type of plant. The catalyst bed consists of a bed of solid material, typically a metal catalyst, which reacts with hydrogen gas to form water. This reaction, known as the catalytic oxidation of hydrogen, allows for the effective removal of hydrogen from the gas stream. The Gas Inlet Compressor in the Hydrogen Plant is from where the Hydrogen enters the Hydrogen Plant. Primary and Air Heater in the Hydrogen removal plant to remove impurities, containments, or moisture to ensure optimal performance and longevity of the catalyst bed. The water separator in the Hydrogen removal plant where the treated gas is passed from and the water is condensed and removed. The Dexo bed in the hydrogen removal plant that operates at low temperature and has high efficiency of hydrogen removal. The proposed hydrogen removal system provides an effective and reliable solution to mitigate the risks associated with hydrogen gas in battery rooms. Its comprehensive approach, combining hydrogen sensing, ventilation, and hydrogen scavenging technologies, ensures a safe environment for battery operation and reduces the potential for catastrophic incidents. Description of Drawings

[0014] Figure 1 shows the brief description of the working of the Hydrogen removal scrubber. A. Gas Inlet from Battery room: The gas stream containing hydrogen enters the hydrogen removal scrubber through an inlet. This gas stream can originate from various sources, such as process off-gases, natural gas, or other gas mixtures. B. Hydrogen Air pump: the gas stream needs to pressurized using air pump. C. Primary &Secondary Air Heater: Prior to entering the catalyst bed, the gas stream undergoes primary air heater to remove impurities, contaminants, or moisture. This ensures optimal performance and longevity of the catalyst bed. D. Contact with catalyst Bed: The gas stream is then directed through the catalyst bed, where the hydrogen removal process takes place. The metal catalyst within the bed facilitates the catalytic oxidation reaction, converting the hydrogen gas to water vapor. E. Condensate water: Some of the Water vapor converts in to condensate water F. Air Cooler: Gas Stream gets cooled off using heat exchanger G. Control valve- Controls the gas and vapor release to the water separator H. Water Separator: The water vapor produced during the catalytic oxidation reaction needs to be separated from the gas stream. This is typically achieved by passing the treated gas through a downstream water separator or condenser, where the water is condensed and removed. I. Condensate water: Remaining Water vapor converts in to condensate water J. Gas Outlet to the battery room: The hydrogen-depleted gas, with the majority of the hydrogen removed, exits the hydrogen removal scrubberthrough a designated outlet. This gas can be further utilized or safely vented depending on the specific application and requirements.

[0015] A hydrogen removal scrubber that utilizes a catalyst bed is a specialized system designed to efficiently remove hydrogen gas from a gas stream. The catalyst bed, also known as a hydrogen scavenger or hydrogen purifier, is a key component in this type of scrubber

[0016] The catalyst bed consists of a bed of solid material, typically a metal catalyst, which reacts with hydrogen gas to form water. This reaction, known as the catalytic oxidation of hydrogen, allows for the effective removal of hydrogen from the gas stream. Detailed Description of Example Embodiments

[0017] The foregoing descriptions outline some pertinent features and objects of the present invention. These may be illustrative of more exhaustive and comprehensive features described later in the application. The technical terms used in this document, are meant with the same meaning as understood by a typical expert of the field which is related to the invention

[0017] Hydrogen gas emission from batteries can be a challenge due to several factors. One of the main reasons is the potential for hydrogen gas to be generated during certain battery chemistries and under specific conditions. Some key points to be considered are enumerated below. 1. Electrolysis reactions: Some types of batteries, such as lead-acid batteries, can undergo electrolysis reactions when overcharged or subjected to high temperatures. Electrolysis occurs when the electrolyte within the battery breaks down into its constituent elements, including hydrogen and oxygen. This process can lead to the release of hydrogen gas. 2. Hydrogen gas buildup: In sealed batteries, such as certain types of rechargeable lithium-ion batteries, the hydrogen gas generated during normal operation can accumulate and potentially lead to increased pressure within the battery. If the pressure builds up excessively, it can cause the battery casing to rupture, posing safety risks such as explosion or fire. 3. Battery damage or degradation: Battery damage or degradation can also contribute to the release of hydrogen gas. For example, physical damage to a battery's casing or components may create pathways for the escape of gases. Additionally, battery aging or deterioration over time can affect the integrity of the cell and increase the likelihood of hydrogen gas emission. 4. Safety concerns: Hydrogen gas is highly flammable and can form explosive mixtures in the presence of air or oxygen. Even a small amount of hydrogen gas, when combined with an ignition source, can lead to hazardous situations. Therefore, controlling the emission and accumulation of hydrogen gas is crucial to ensure the safe operation and handling of batteries. To address these challenges, battery manufacturers and researchers focus on developing safer battery designs, improving battery management systems, and implementing enhanced safety measures. These efforts aim to minimize hydrogen gas emission, mitigate the associated risks, and ensure the safe use of batteries in various applications.

[0018] Need to mention that Hydrogen is difficult to separate from atmospheric gases primarily due to its low concentration and its tendency to form stable molecular bonds with other elements. Some of the key reasons for this difficulty are enumerated below. 1. Low concentration: Hydrogen exists in the Earth's atmosphere at a relatively low concentration, approximately 0.00005% by volume. This means that for every million molecules of air, there are only about 50 molecules of hydrogen. The low concentration makes it challenging to extract enough hydrogen for practical purposes. 2. Molecular bonding: Hydrogen is highly reactive and readily forms molecular bonds with other elements. In the atmosphere, it primarily exists as diatomic molecules (H2), where two hydrogen atoms are chemically bonded together. This molecular bonding makes it difficult to separate hydrogen from other gases, as it requires breaking these stable bonds. 3. Similar properties: Hydrogen shares certain physical and chemical properties with other atmospheric gases, such as nitrogen (N2) and oxygen (02). For instance, hydrogen and nitrogen both have low boiling points and are relatively nonpolar. These similarities make it challenging to selectively separate hydrogen from these gases based solely on their physical properties. 4. Energy-intensive separation processes: To separate hydrogen from atmospheric gases, energy-intensive processes are typically employed, such as steam methane reforming or electrolysis. These processes require significant amounts of energy input and specialized equipmentto breakthe molecular bonds between hydrogen and other gases. These factors contribute to the complexity and cost of separating hydrogen. 5. Diffusion limitations: Due to the low concentration of hydrogen in the atmosphere, diffusion becomes a limiting factor. Diffusion is the process by which gases mix and spread out due to their random molecular motion. Since the concentration of hydrogen is so low, it diffuses slowly and disperses into the atmosphere quickly, making it challenging to capture and concentrate for separation. It is worth noting that while separating hydrogen from atmospheric gases is challenging, there are various methods and technologies under development to improve the efficiency and feasibility of hydrogen extraction. These advancements aim to support the growing interest in hydrogen as a clean and renewable energy source.

[0019] The following are some of the commonly employed equipment and technologies for low concentration hydrogen separation. The choice of equipment depends on factors such as the specific application, required purity levels, scale of operation, and cost considerations. 1. H2 Removal using Palladium Membrane Systems Palladium-based membranes are commonly used for low concentration hydrogen separation. These membranes selectively allow hydrogen molecules to permeate through while blocking other gases. The process typically involves passing the gas mixture over one side of the palladium membrane, allowing hydrogen to passthrough and collecting it on the other side. This method is efficient for separating hydrogen even at low concentrations. This option is very good if plant basic purpose is to recover and hydrogen for further use. 2. H2 Removal using Electrochemical Separators Electrochemical hydrogen separators, such as proton exchange membrane (PEM) cells, utilize a solid electrolyte membrane that selectively conducts protons (H+) while blocking other gas molecules. When a voltage is applied across the membrane, hydrogen molecules dissociate into protons and electrons on one side and then recombine on the other side, resulting in the separation of hydrogen gas. These separators are particularly useful for low concentration hydrogen separation. 3. H2 Removal using Cryogenic Distillation Cryogenic distillation is a process that exploits the differences in boiling points of gases to separate them. In this method, the gas mixture is cooled to extremely low temperatures, typically below the boiling point of hydrogen (-252.87°C or -423.17°F). As the gas mixture is gradually heated, hydrogen vaporizes first, and the resulting vapor is collected separately. Cryogenic distillation is effective for separating hydrogen from gas mixtures even at low concentrations. 4. H2 Removal using Pressure Swing Adsorption (PSA) Pressure Swing Adsorption (PSA) with Catalytic Purification can also be used for low concentration hydrogen separation. However, to enhance their performance, a catalytic purification step is added. After the PSA process, the hydrogen-rich gas stream is passed through a catalyst bed that further removes impurities, such as carbon monoxide (CO) and trace hydrocarbons, to obtain a purer hydrogen product. 5. H2 Removal using Thermal Oxidizers A thermal oxidizer for hydrogen, also known as a hydrogen thermal oxidizer or hydrogen combustion chamber, is a device used to efficiently and safely combust hydrogen gas. It is commonly employed in industrial processes where hydrogen needs to be oxidized or burned to eliminate pollutants and achieve environmental compliance.

[0020] The main purpose of a hydrogen scrubber is to remove the gas and turn in to water. This is important not only economic reasons, but also to minimise the risk of explosion hazard. Hydrogen gas scrubbing does also have challenges, especially when it comes to effectively and efficiently removing hydrogen gas from a specific environment. The reasons why hydrogen gas scrubbing can be challenging are enumerated below: 1. High diffusivity: Hydrogen gas has a very high diffusivity, meaning it can easily spread and disperse throughout a given space. This makes capturing and containing hydrogen gas challenging, as it can quickly escape from the scrubbing system if not properly controlled. 2. Small molecular size: Hydrogen gas molecules are small, which makes them difficult to capture using traditional scrubbing techniques. Many commonly used scrubbing materials and methods are designed for larger molecules or particulate matter and may not be as effective at capturing and removing hydrogen gas. 3. Low concentration and dilution: In certain applications, such as industrial processes or fuel cells, the concentration of hydrogen gas can be relatively low. This makes scrubbing even more challenging, as it requires efficiently extracting and removing trace amounts of hydrogen gas from a larger volume of air or gas mixture. 4. Selectivity: Hydrogen gas scrubbing often needs to be selective, targeting only hydrogen gas while leaving other gases or contaminants unaffected. Achieving this selectivity can be difficult, as hydrogen gas may be present alongside other gases or impurities that also need to be removed. Developing materials or methods that specifically target and capture hydrogen gas without interfering with other components can be a significant challenge. 5. Efficiency and cost-effectiveness: Hydrogen gas scrubbing methods need to be both efficient and cost-effective. They should achieve high removal efficiencies while minimizing energy consumption and operational costs. Developing scrubbing systems that meet these criteria does require significant research and development efforts. Despite the challenges, researchers and engineers are actively exploring and involved in the development of various hydrogen gas scrubbing techniques. These techniques include the use of selective adsorbents, membranes, catalysts, and novel materials to improve hydrogen gas capture and separation processes. These advancements aim to facilitate the safe handling, storage, and utilization of hydrogen gas in different applications while addressing the challenges associated with its scrubbing.

[0021] Based on the design and configuration requirement for the of a hydrogen removal scrubber, it is recommended using a catalyst bed-based hydrogen removal scrubber. The operating conditions, catalyst selection and overall system design are tailored to meet the client unique requirements for the battery room outlet gas. A hydrogen removal scrubber that utilizes a catalyst bed is a specialized system designed to efficiently remove hydrogen gas from a gas stream. The catalyst bed, also known as a hydrogen scavenger or hydrogen purifier, is a key component in this type of plant. The catalyst bed consists of a bed of solid material, typically a metal catalyst, which reacts with hydrogen gas to form water. This reaction, known as the catalytic oxidation of hydrogen, allows for the effective removal of hydrogen from the gas stream. The process of hydrogen removal using a catalyst bed typically involves the following steps: A. Gas Inlet from Battery room: The gas stream containing hydrogen enters the hydrogen removal scrubber through an inlet. This gas stream can originate from various sources, such as process off-gases, natural gas, or other gas mixtures. B. Hydrogen Air pump: the gas stream needs to pressurized using air pump. C. Primary &Secondary Air Heater: Prior to entering the catalyst bed, the gas stream undergoes primary air heater to remove impurities, contaminants, or moisture. This ensures optimal performance and longevity of the catalyst bed. D. Contact with catalyst Bed: The gas stream is then directed through the catalyst bed, where the hydrogen removal process takes place. The metal catalyst within the bed facilitates the catalytic oxidation reaction, converting the hydrogen gas to water vapor. E. Condensate water: Some of the Water vapor converts in to condensate water F. Air Cooler: Gas Stream gets cooled off using heat exchanger G. Control valve- Controls the gas and vapor release to the water separator H. Water Separator: The water vapor produced during the catalytic oxidation reaction needs to be separated from the gas stream. This is typically achieved by passing the treated gas through a downstream water separator or condenser, where the water is condensed and removed. I. Condensate water: Remaining Water vapor converts in to condensate water J. Gas Outlet to the battery room: The hydrogen-depleted gas, with the majority of the hydrogen removed, exits the hydrogen removal scrubberthrough a designated outlet. This gas can be further utilized or safely vented depending on the specific application and requirements.

[0022] The catalyst bed in a hydrogen removal scrubber provides several advantages, including high efficiency in hydrogen removal, low operating temperatures, and a relatively simple and compact design. The catalyst within the catalyst bed is carefully selected to provide optimal performance, longevity and resistance to potential contaminants present in the gas stream.

[0023] For the sizing the hydrogen scrubber, it has been recommended that the inlet to the scrubber should be 10% of the total flow from the battery room, that way, the H2 concentration of 1% would never reach. The feed gas composition of 1% hydrogen and rest is oxygen and air.

[0024] If the Hydrogen scrubber is successfully able to remove hydrogen gas from battery room gases, it can benefit in several ways. Here are some potential advantages: 1. Safety improvement: Hydrogen gas is highly flammable, and its removal from battery room gases can significantly enhance safety. By reducing the presence of hydrogen, the risk of explosions, fires, and other accidents related to hydrogen gas is mitigated. This can protect employees, equipment, and facilities, leading to a safer working environment. 2. Regulatory compliance: Many industrial sectors have specific regulations and safety standards concerning hydrogen gas management. By effectively removing hydrogen gas from battery room gases, a company can ensure compliance with these regulations. This avoids potential fines, penalties, or legal issues that may arise from non-compliance. 3. Enhanced operational reliability: High levels of hydrogen gas in battery room gases can adversely affect the performance and reliability of electrical systems and equipment. Hydrogen gas can lead to corrosion, insulation breakdown, and other issues. By removing hydrogen gas, it can improve the reliability and longevity of the electrical infrastructure, reducing downtime and maintenance costs. 4. Improved energy efficiency: Hydrogen gas, when released into the atmosphere, represents wasted energy. Hydrogen is a valuable fuel source and can be utilized for power generation or other applications. By capturing and utilizing the hydrogen gas instead of allowing it to escape, companies can maximize their energy efficiency and potentially offset energy costs. 5. Environmental benefits: Hydrogen gas is considered a greenhouse gas, and its release into the atmosphere contributes to environmental pollution and climate change. By effectively removing hydrogen gas from battery room gases, it can reduce the environmental impact and demonstrate the commitment to follow sustainable and responsible practices. 6. Reputation and stakeholder confidence: Taking proactive measures to address hydrogen gas emissions demonstrates commitment to safety, compliance, and environmental responsibility. Overall, successfully removing hydrogen gas from battery room gases can lead to improved safety, regulatory compliance, operational reliability, energy efficiency, environmental sustainability.

[0024] These and other features, objects and advantages of the present invention will be readily visible to the persons ordinarily skilled in the art related to this field comprehending in entirety the above characteristics, following descriptions and claims of the present invention.

Claims

We claim1. A Hydrogen removal scrubber that utilizes a catalyst bed and is a specialized system designed to efficiently remove hydrogen from a gas stream.

2. The Catalyst bed in Claim 1, also known as a hydrogen scavenger or hydrogen purifier, is a key component in this type of scrubber.

3. The Catalyst bed in Claim 1 compromising of, a bed of solid material, typically a metal catalyst, which reacts with hydrogen gas to form water. The reaction formed is known as the catalytic oxidation of hydrogen, allows for the effective removal of hydrogen from the gas stream4. The Gas Inlet Compressor in the Hydrogen scrubber from where the Hydrogen enters the Hydrogen scrubber5. Primary and Air Heater in the Hydrogen removal scrubber to remove impurities, containments, or moisture to ensure optimal performance and longevity of the catalyst bed.

6. Metal catalyst within the bed that facilitates the catalytic oxidation reaction, converting the hydrogen gas to water vapor.

7. The water separator in the Hydrogen removal scrubber where the treated gas is passed from and the water is condensed and removed.

8. The catalyst bed in the hydrogen removal scrubber that operates at low temperature and has high efficiency of hydrogen removal.15