Hydrogen Production by the High Temperature Combination of the Water GasShift
水素発生过电压的英文
水素発生过电压的英文Title: Hydrogen Evolution Overvoltage: An OverviewHydrogen evolution overvoltage, a key concept in electrochemistry, refers to the additional voltage required for the electrolysis of water beyond its theoretical value. This phenomenon plays a critical role in various applications such as hydrogen production for fuel cells and renewable energy storage.The process of water electrolysis involves the dposition of water into hydrogen and oxygen using an electric current. The minimum potential required for this reaction is called the thermodynamic potential or reversible potential. However, in practical scenarios, a higher potential, known as overpotential, is needed to drive the reaction at an appreciable rate. This excess voltage is the hydrogen evolution overvoltage.There are several factors that contribute to the hydrogen evolution overvoltage. These include the nature of the electrode material, the surface condition of the electrode, the concentration of ions in the solution, and the temperature. For instance, a rough electrode surface can increase the overvoltage due to mass transfer limitations, while high ion concentrations can lead to increased ohmic losses.One approach to minimize the hydrogen evolution overvoltage is by using catalysts. Catalysts lower the activation energy barrier for the reaction, thereby reducing the required overpotential. Platinum and its alloys aremonly used as catalysts for hydrogen evolution reactions due to their high efficiency.Understanding and controlling hydrogen evolution overvoltage is crucial for improving the efficiency of water electrolysis and making hydrogen production more economically viable. It also has implications for the development of advanced energy conversion and storage technologies.In conclusion, hydrogen evolution overvoltage is aplex phenomenon influenced by multiple factors. Further research in this area could lead to significant advancements in our ability to produce and utilize hydrogen as a clean and sustainable energy source.。
哈气产生雾气的原理英语作文
哈气产生雾气的原理英语作文英文回答：Exhalation Fog: A Scientific Explanation.Exhalation fog, also known as breath fog or steam breath, is a natural phenomenon that occurs when warm, moist air from the lungs encounters cold air outside the mouth and nose. As the warm air cools, the water vapor it contains condenses into tiny water droplets, creating the visible "fog" or "steam."The process of exhalation fog formation can be explained by the principles of thermodynamics and gas laws. Thermodynamics tells us that heat flows from areas of high temperature to areas of low temperature. When warm air from the lungs meets cold air outside, the heat from the warmair transfers to the cold air, causing the warm air to cool down.Gas laws, specifically Boyle's Law and Charles' Law, explain the behavior of gases as they change in temperature and pressure. Boyle's Law states that the pressure of a gas is inversely proportional to its volume, meaning that as the volume of a gas increases, its pressure decreases. Charles' Law states that the volume of a gas is directly proportional to its temperature, meaning that as the temperature of a gas increases, its volume increases.In the case of exhalation fog, as the warm air from the lungs cools down, its volume decreases according to Boyle's Law. This decrease in volume increases the pressure of the water vapor within the air, forcing it to condense into liquid droplets. These droplets form the visible fog or steam that we see.中文回答：哈气产生雾气的原理。
Hydrogen Production
2.
Hydrogen Production Processes
Steam Methane Reforming Coal Gasification Partial Oxidation of Hydrocarbons Biomass Gasification Biomass Pyrolysis Electrolysis Thermochemical Photochemical Photobiological
CH4 + H2O → CO + 3 H2
Additional hydrogen can be recovered by a lower-temperature gas-shift reaction with the carbon monoxide produced. The reaction is summarized by:
Current global hydrogen production
48%
from natural gas
30%
18% 4%
from oil
from coal
from electrolysis of water
Primary Uses for Hydrogen Today
1.
Hydrogen Production
Hocking College Nelsonville, Ohio
One Advantage of using hydrogen
1.
One advantage is that it stores approximately 2.6 times the energy per unit mass as gasoline, and the disadvantage is that it needs about 4 times the volume for a given amount of energy. A 15 gallon automobile gasoline tank contains 90 pounds of gasoline. The corresponding hydrogen tank would be 60 gallons, but the hydrogen would weigh only 34 pounds.
生物制氢原理英语作文
生物制氢原理英语作文The Principles of Biological Hydrogen ProductionBiological hydrogen production, a sustainable and environmentally friendly technology, has emerged as a promising alternative to traditional hydrogen generation methods. At its core, this process harnesses the natural abilities of microorganisms to convert organic matter into hydrogen gas.The principle behind biological hydrogen production is based on the metabolism of these microorganisms, specifically their ability to engage in anaerobic respiration. Under anaerobic conditions, these microbes consume organic substrates such as carbohydrates, fats, or proteins and convert them into hydrogen gas and carbon dioxide as by-products. This reaction is catalyzed by specific enzymes and occurs within the microbial cells.The process begins with the fermentation of organic matter by anaerobic bacteria. During this fermentation, the organic matter is broken down into simpler compounds, releasing electrons and protons. These electrons and protons are then used by the bacteria to reduce protons to hydrogengas. The overall reaction is exothermic, meaning it releases heat, and does not require external energy input.The key to efficient biological hydrogen production lies in the selection of appropriate microbial cultures and optimizing the fermentation conditions. Certain bacteria, known as hydrogen-producing bacteria, are particularly efficient at converting organic matter into hydrogen. Additionally, factors like temperature, pH, and the type and concentration of organic substrate can significantly affect the rate and yield of hydrogen production.In conclusion, biological hydrogen production offers a sustainable and renewable route to obtaining this valuable energy carrier.。
阳极蒸发 阴极粉化 英语
阳极蒸发阴极粉化英语英文回答：The evaporation of the anode and the sputtering of the cathode are two important phenomena that occur during the process of electrical discharge machining (EDM).Anode evaporation is the process in which the material of the anode is vaporized due to the high temperature generated by the electrical discharge. The vaporized material then condenses on the surface of the cathode, forming a thin layer of material. The thickness of the layer depends on the discharge conditions, such as the discharge current, the discharge voltage, and the duration of the discharge.Cathode sputtering is the process in which the material of the cathode is ejected from the surface due to the impact of high-energy ions. The ions are generated in the plasma that is formed between the anode and the cathode.The sputtered material can then redeposit on the surface of the anode, or it can be ejected from the discharge zone.The rate of sputtering depends on the discharge conditions, as well as the material of the cathode.中文回答：阳极蒸发是在放电加工 (EDM) 过程中发生的两个重要现象之一，阳极材料由于电火花产生的高温而蒸发。
美国能源部制氢
Hydrogen ProductionHydrogen is an energy carrier, not an energysource — it stores and delivers energy in a usable form, but it must be produced from compoundsthat contain it.Hydrogen can be produced using diverse,domestic resources including fossil fuels, such ascoal (with carbon sequestration) and natural gas; nuclear; and biomass and other renewable energy technologies, such as wind, solar, geothermal,and hydroelectric power. This great potential fordiversity of supply is an important reason why hydrogen is such a promising energy carrier.Hydrogen can be produced at large central plants as far as several hundred miles from the point of end-use; semi-centrally, 25 to 100 miles from the point of end-use; or in small distributed units located at or very near the point of end-use, such as at refueling stations or stationary power sites.How Is Hydrogen Produced? Researchers are developing a wide range of technologies to produce hydrogen economically from a variety of resources in environmentally friendly ways.Natural Gas ReformingHydrogen can be produced from methane in natural gas using high-temperature steam. This process, called steam methane reforming, accounts for about 95 percent of the hydrogen used today in the United States. Another method, called partial oxidation, produces hydrogen by burning methane in air. Both steam reforming and partial oxidation produce a “synthesis gas,” which is reacted with water to produce more hydrogen.Renewable ElectrolysisElectrolysis uses an electric current to split water into hydrogen and oxygen. The electricity required can be generated using renewable energy technologies, such as wind, solar, geothermal, and hydroelectric power.GasificationGasification is a process in which coal orbiomass is converted into gaseous components by applying heat under pressure and in the presenceof steam. A subsequent series of chemical reactions produces a synthesis gas, which isreacted with steam to produce more hydrogenthat then can be separated and purified.④Producing hydrogen directly from coal bygasification and reforming processes is muchmore efficient than burning coal to makeelectricity that is then used to makehydrogen. Researchers are developing carboncapture and sequestration technologies toseparate and store the carbon dioxide (CO2)produced in this process. With carboncapture and sequestration, hydrogen can beproduced directly from coal with near-zerogreenhouse gas emissions.④Like coal, biomass can be gasified using hightemperatures and steam to produce hydrogen.Because biomass resources consume CO2 inthe atmosphere as part of their natural growthprocess, producing hydrogen throughbiomass gasification releases near-zero netgreenhouse gases.Renewable Liquid ReformingBiomass can also be processed to make renewable liquid fuels, such as ethanol or bio-oil,that are relatively convenient to transport and canbe reacted with high-temperature steam toproduce hydrogen at or near the point of end-use. Hydrogen can be produced using a variety of resources. This diversity of sources makes hydrogen a promising energy carrier and enableshydrogen production almost anywhere in the world.Nuclear High-Temperature ElectrolysisHeat from a nuclear reactor can be used to improve the efficiency of water electrolysis to produce hydrogen. By increasing the temperature of the water, less electricity is required to split it into hydrogen and oxygen, which reduces the total energy required.High-Temperature Thermochemical Water-SplittingAnother water-splitting method uses high temperatures generated by solar concentrators (special lenses that focus and intensify sunlight) or nuclear reactors to drive a series of chemical reactions that split water. All of the chemicals used are recycled within the process.Photobiological and PhotoelectrochemicalWhen certain microbes, such as green algae and cyanobacteria, consume water in the presence of sunlight, they produce hydrogen as a byproduct of their natural metabolic processes. Similarly, photoelectrochemical systems produce hydrogen from water using special semiconductors and energy from sunlight.What Are the Challenges?The greatest technical challenge to hydrogen production is cost reduction. For transportation, a key driver for energy independence, hydrogen must be cost-competitive with conventional fuels and technologies on a per-mile basis. This means that the cost of hydrogen — regardless of the production technology, and including the cost of delivery — must be in the range of $2.00 to $3.00 per gallon gasoline equivalent (untaxed). Note: Transportation fuels are often compared based on their equivalency to gasoline. The amount of fuel with the energy content of one gallon of gasoline is referred to as a gallon gasoline equivalent (gge).Research DirectionsHydrogen production technologies are in various stages of development. Some technologies, such as steam methane reforming, are becoming well-developed and can be used in the near term. Others, such as high-temperature thermochemical water-splitting, photobiological, and photoelectrochemical, are in the very early stages of laboratory development and considered potential pathways for the long-term.In general, research is focused on reducing capital equipment, operations, and maintenance costs, as well as improving the efficiency of hydrogen production technologies. Related research includes developing carbon sequestration technology to ensure that coal-based hydrogen production releases almost no greenhouse gas emissions and improving agricultural handling practices and breeding efforts to reduce the cost of biomass resources used in hydrogen production.For print copies of this fact sheet, please call the DOE Energy Efficiency and Renewable Energy Information Center at 877-EERE-INF(O)/877-337-3463. D i d y o u k n o w…Hydrogen is an energy carrier, not an energy source, meaning that it stores and delivers energy in a usable form.Hydrogen can be produced using abundant and diverse domestic energy resources, including fossil fuels, such as natural gas and coal; renewable energy resources, such as solar, wind, and biomass; and nuclear energy.Using hydrogen as a form of energy can not only reduce our dependence on imported oil, but also benefit the environment by reducing emissions of greenhouse gases and criteria pollutants that affect our air quality.The DOE Hydrogen Program supports research and development of fuel cell and hydrogen production, storage, and delivery infrastructure technologies needed to support hydrogen fuel cells for use in transportation and electricity generation.The DOE Hydrogen Program works with industry, academia, national laboratories, and other federal and international agencies to overcome critical technology barriers, facilitate the development of model codes and standards, validate hydrogen fuel cell technologies in real world conditions, and educate key stakeholders who can facilitate the use of hydrogen and fuel cell technologies.Increase Your H2IQ! Visit November 2008Hydrogen Production。
电解制氢英文书籍
电解制氢英文书籍Electrolytic Hydrogen Production: A Comprehensive Guide in EnglishIntroduction:The field of electrolytic hydrogen production is rapidly gaining attention due to its potential as a clean and sustainable energy source. Understanding the principles and techniques involved in this process is crucial for researchers, engineers, and policymakers. In this article, we will explore some highly recommended English books that delve into the various aspects of electrolytic hydrogen production.1. "Electrochemical Hydrogen Production" by Craig Grimes, Elizabeth Taylor, and Sudhir KaleThis book provides a comprehensive overview of the electrochemical methods employed in hydrogen production. It covers the fundamental principles, various types of electrolyzers, and strategies to improve efficiency and reduce costs. The authors also discuss the current status and future prospects of electrochemical hydrogen production technologies.2. "Hydrogen Production: Fundamentals and Processes" by Anoop Singh, Subash C. Bhatia, and P.S. GhoshdastidarThis book offers a comprehensive account of hydrogen production techniques, including electrolysis. It covers both traditional and advanced methods of hydrogen production, providing a thorough understanding of their principles, advantages, and limitations. The authors also discuss the integration of renewable energy sources and the role of electrolytic hydrogen in the context of the energy transition.3. "Hydrogen Economy: Supply Chain, Life Cycle Analysis and Energy Transition for Sustainability" by Yang Zhang and Sankar BhattacharyaThis book explores the broader concept of the hydrogen economy and its potential impact on achieving sustainability. While covering various aspects of hydrogenproduction, it also addresses topics such as hydrogen storage, transportation, and utilization. The authors emphasize the importance of electrolytic hydrogen production in driving the energy transition towards a low-carbon future.4. "Renewable Hydrogen Technologies: Production, Purification, Storage, Applications and Safety" edited by Luis M. Gandia and Gurutze ArzamediThis book focuses on the technical aspects of renewable hydrogen technologies, including electrolytic production. It provides insights into the latest advancements in hydrogen purification, storage, and applications. Additionally, it discusses safety aspects associated with the large-scale production and utilization of hydrogen as an energy carrier.Conclusion:The books listed above offer a comprehensive understanding of electrolytic hydrogen production and its role in the transition towards a sustainable future. They cover various aspects, from fundamental principles to advanced techniques, ensuring readers gain a holistic view of this emerging field. Whether you are a researcher, engineer, or policymaker, these resources will be invaluable in expanding your knowledge and contributing to the advancement of electrolytic hydrogen production technologies.。
海草产氧的工作原理英语解释
海草产氧的工作原理英语解释The Working Principle of Oxygen Production by Seagrass.Seagrass, an integral part of the marine ecosystem, performs a crucial role in oxygen production through photosynthesis. This process converts sunlight, carbon dioxide, and water into glucose and oxygen, providing avital source of oxygen for marine life. Unlike terrestrial plants, seagrass relies on carbon dioxide dissolved in the water for photosynthesis, releasing oxygen through itsroots and stomata into the surrounding water.The photosynthesis carried out by seagrass occurs in a similar manner to that of terrestrial plants, but with some unique adaptations to the aquatic environment. The chloroplasts, the organelles responsible for photosynthesis, are optimized for low-light conditions, enabling seagrassto thrive in environments with limited sunlight penetration. This adaptation allows seagrass to be a significant contributor to oxygen production even in shallow, turbid,or deepwater habitats.During photosynthesis, seagrass absorbs photons of sunlight, exciting the electrons in the chlorophyll pigments. These excited electrons are then passed through a series of electron transport chains, ultimately resulting in the formation of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). These energy-rich molecules are used to convert carbon dioxide and water into glucose, a process known as carbon fixation. Oxygen is released as a by-product of this reaction, enriching the surrounding water with dissolved oxygen.The oxygen produced by seagrass is crucial for maintaining the health and vitality of marine ecosystems. It not only supports the respiratory needs of aquatic organisms but also contributes to maintaining water quality and clarity. By releasing oxygen, seagrass helps to counterbalance the oxygen depletion caused by organic matter decomposition and other biological processes.Moreover, seagrass meadows are known as "the lungs ofthe sea" due to their significant role in oxygen production. These meadows are also essential for carbon sequestration, storing carbon dioxide in their tissues and sediments. This carbon sequestration process helps to mitigate the effectsof climate change by reducing the concentration of carbon dioxide in the atmosphere.Beyond its role in oxygen production and carbon sequestration, seagrass also plays a vital role in ecosystem services. It provides habitat and nursery grounds for many marine species, including fish, invertebrates, and turtles. The dense root systems of seagrass stabilize sediments, protecting coastlines from erosion and storm surges. Additionally, seagrass meadows filter pollutantsand nutrients, improving water quality and maintaining the health of adjacent coral reefs and other marine habitats.In summary, the working principle of oxygen production by seagrass is based on the photosynthetic process that converts sunlight, carbon dioxide, and water into glucose and oxygen. This process not only supports the respiratory needs of marine life but also contributes to maintainingwater quality, carbon sequestration, and the overall health and stability of marine ecosystems. The significance of seagrass meadows in oxygen production and carbon sequestration makes them crucial for addressing climate change and safeguarding the integrity of marine ecosystems.。
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CO + H2O = CO2 + H2
(1)
*To whom correspondence should be addressed: Email: virginia.collins@.mx* , alejandro.lopez@.mx†
Phone: +52-614-439-1129, +52-614-439-4815; Fax: +52-614-439-1130
Keywords: Hydrogen Production, Water Gas Shift, CO2 Absorption.
1. INTRODUCTION
Hydrogen is an important raw material for today chemical and
petroleum industry [1]. Recently, an important research field has
regeneration of the carbonated metal (MeCO3) with pure CO2 can produce a high purity stream of this gas through the reverse reac-
catalyst for this to proceed. Additionally, as a result of the CO2
removal during the WGS reaction the system reaches the thermo-
dynamic equilibrium, thus producing a higher hydrogen content in
Miguel A. Escobedo Bretado, Manuel D. Delgado Vigil, Jesus Salinas Gutiérrez, Alejandro López Ortiz† and Virginia Collins-Martínez*
Departamento de Química de Materiales, Centro de Investigación en Materiales Avanzados, S. C. Miguel de Cervantes 120, Chihuahua, Chih., México 31109.
The hydrogen production through the Absorption Enhanced Water Was Shift (AEWGS) has the great flexibility of using different sources of syngas to produce a gas with high hydrogen content. In this process the reaction between CO and water vapor (equation 1) is combined with the simultaneous removal of CO2 in
and carbon monoxide [5]. Then this syngas is sent to another reac-
tor aimed to increase its hydrogen concentration through the water
gas shift reaction (WGS), equation (1), where CO and H2O are converted to H2 and CO2 by:
tures in the order of 250°C < T < 800°C and thermodynamically
the WGS reaction is favored [7]. In theory at this temperature range
the reaction is homogeneous and therefore it would not require a
the product gas, saving energy by avoiding the inefficient heat
exchangers present in the conventional WGS process and conse-
quently increasing the overall process efficiency. Furthermore,
23
24
Miguel A. Escobedo Bretado et al. / J. New Mat. Electrochem. Systems
one step through the following reaction:
MeO + CO2 = MeCO3
(2)
where MeO is a metal oxide capable to be carbonated at tempera-
emerged, which deals with the production of high purity hydrogen
for power generation purposes through fuel cells [2].
Today, industrial technologies for hydrogen production are
Conventionally, carbon dioxide is removed through liquid absorption by amines or via physical adsorption by means of pressure swing adsorption (PSA) when the amine-absorption process is used, water is removed and the final product consists of high purity hydrogen (99%) [6]. Recently, new processes are being developed that combine the solid CO2 capture and hydrogen production. Among all these processes the sorption enhanced water gas shift (SEWGS) [7] and sorption enhanced steam reforming (SER) [8, 9] are expected to improve energy efficiencies from their basic conventional processes (SMR and WGS), making the hydrogen production through these routes an important technological advance towards the coming hydrogen economy [9]. From these two concepts, perhaps the one that has received less attention by the scientific community is the AEWGS, since hydrogen production and specifically using solid CO2 capture plays an important role in the coming “mobile” hydrogen generation technologiesand the integrated combined coal gasification
cycle (IGCC) [4]. These processes partially oxide the fuel generat-
ing synthesis gas (syngas), which is composed of mainly hydrogen
Journal of New Materials for Electrochemical Systems 12, 023-028 (2009) © J. New Mat. Electrochem. Systems
Hydrogen Production by the High Temperature Combination of the Water Gas Shift and CO2 Absorption Reactions
Received: January 20, 2009, Accepted: February 24, 2009
Abstract: Hydrogen production through the water gas shift (WGS) reaction requires two consecutive catalytic steps followed by CO2 separation. However, combination of the WGS reaction and CO2 capture by a solid absorbent opens the opportunity to produce high purity H2 in one single step (Absorption Enhanced WGS, AEWGS). This process in theory would not require a catalyst. Therefore, the AEWGS was experimentally studied using a quartz-made fixed bed reactor. CO2 absorbents tested were calcined dolomite, (CaO*MgO) and sodium zirconate (Na2ZrO3). Experimental conditions were: 1 cm3 of absorbent with feed at 50 cm3/min, 5% CO, 20% H2O and balance He and N2. Employing a space velocity of SV = 3000h-1 at 600°C and atmospheric pressure. Dry-basis and inert-free composition using CaO*MgO resulted in a product gas content of 85% H2, 7% CO2, and 8% CO, while with the use of Na2ZrO3, a concentration of 50% H2, 30% CO and 20% CO2 was obtained. Results suggest that the WGS and CaO*MgO carbonation reaction rates are similar enough to reach 97% of the equilibrium H2 composition. WGS was determined to be a catalytic reaction in the range of 600-950°C.