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科学家发现直接从海水中制造氢气的新方法时间：2023-03-31 目前世界上几乎所有的氢气都来自化石燃料，生产过程中每年产生大约8.3亿吨二氧化碳 绿色制氢工艺既昂贵又依赖新淡水或淡化水 电解槽目前使用昂贵的催化剂，消耗大量的能源和水——生产一公斤氢气大约需要9升淡水 中国石化新闻网讯 据油价网2023年3月26日报道，皇家墨尔本理工大学（RMIT）的研究人员已经开发出一种更便宜、更节能的方法，直接从海水中制造氢气。这是迈向真正可行的绿色氢气工业的关键一步，这种新方法将海水直接分解为氢气和氧气。 新工艺跳过了海水淡化及其相关成本、能源消耗和二氧化碳排放。 这种新方法已经在威利出版社的《Small》杂志上发表的一项实验室规模的研究中得到了详细介绍。 长期以来，氢气一直被誉为一种清洁的未来燃料，是解决关键能源挑战的潜在解决方案，特别是对于制造业、航空业和航运业等更难脱碳的行业。 目前，世界上几乎所有的氢气都来自化石燃料，其生产每年产生大约8.3亿吨二氧化碳，相当于英国和印度尼西亚年二氧化碳排放量的总和。 但是，通过水解来制造的零排放的“绿色”氢气非常昂贵，在商业上基本上不可行，而且仅占全球氢气总产量的1%。 首席研究员、皇家墨尔本理工大学副校长高级研究员纳西尔·马哈茂德博士说，绿色制氢过程既昂贵，又依赖于新淡水或淡化水。 马哈茂德博士解释说：“我们知道氢气作为一种清洁能源具有巨大的潜力，特别是对于许多不能轻易转换为可再生能源的行业。但要实现真正的可持续发展，我们使用的氢气必须在整个生产周期中100%无碳，而且不能破坏世界宝贵的淡水资源。” 马哈茂德博士说：“我们直接从海水中生产氢气的方法简单、可扩展，比目前市场上的任何生产绿色氢气方法都更具成本效益。随着进一步的发展，我们希望这可以推动澳大利亚建立一个蓬勃发展的绿色氢气工业。” 为了制造绿色氢气，利用电解槽通过电流将水分解成氢气和氧气的组成元素。 这些电解槽目前使用昂贵的催化剂，消耗大量的能源和水——大约需要9升淡水才能生产出1公斤氢气。它们还会产生有毒物质：不是二氧化碳，而是氯气。 马哈茂德继续说道：“使用海水的最大障碍是氯气，它可以作为副产品产生。如果我们要在不解决这个问题的情况下满足世界对氢气的需求，我们每年将生产2.4亿吨氯气——这是世界氯气总需求量的3到4倍。用制氢来取代化石燃料生产的氢气是没有意义的，因为它可能会以不同的方式破坏我们的环境。” “我们的工艺不仅不产生二氧化碳，也不产生氯气。”马哈茂德补充说。 皇家墨尔本理工大学清洁能源与环境多学科材料(MC2E)研究小组的一个团队设计的新方法使用了一种特殊类型的催化剂，专门用于海水。 这个与博士候选人Suraj Loomba一起的研究专注于生产高效、稳定的催化剂，这种催化剂的制造具有成本效益。 “我们的方法专注于通过一种简单的方法改变催化剂的内部化学成分，这使得它们相对容易大规模生产，因此它们可以很容易地在工业规模上合成。”Loomba指出。 马哈茂德补充说：“这些新型催化剂运行消耗的能量非常少，并且可以在室温下使用。虽然已经开发了其他用于海水拆分的实验催化剂，但它们很复杂，难以规模化。” 马哈茂德解释说，这项技术有望显著降低电解槽的成本，足以满足澳大利亚政府的绿色氢气生产目标，即每公斤2澳元，使其与化石燃料来源的氢气具有竞争力。 皇家墨尔本理工大学的研究人员正在与行业伙伴合作开发这项技术的各个方面。研究的下一阶段将是开发一个原型电解槽，它结合一系列催化剂来生产大量的氢气。 这种新方法已经提交了临时专利申请。 这种制氢新方法对于那些阳光充足、风电充沛、容易获得海水的地区来说真的很不错。这种情况可能会与化石生产资源形成竞争。对电力和过程系统的投资是相当可观的。但它能否持续数十年，实现良好的利润，这是一个严重的问题。 皇家墨尔本理工大学团队的工作看起来是迄今为止我们见过的最成功的高度创新的制氢系统和工艺。低温和相对较低的功率，似乎不需要水的准备，这无疑是向前迈出的一大步。 “一系列催化剂”可能如何影响生产成本，这将是一件有趣的事情。 李峻 编译自 油价网 原文如下： Scientists Find New Way To Make Hydrogen Directly From Seawater · Almost all the world’s hydrogen currently comes from fossil fuels and its production is responsible for around 830 million metric tons of carbon dioxide a year. · green hydrogen production processes were both costly and relied on fresh or desalinated water. · electrolysers currently use expensive catalysts and consume a lot of energy and water – it can take about nine liters to make one kilogram of hydrogen. RMIT University researchers have developed a cheaper and more energy-efficient way to make hydrogen directly from seawater. In a critical step towards a truly viable green hydrogen industry the new method splits the seawater directly into hydrogen and oxygen. The new process skips the need for desalination and its associated cost, energy consumption and carbon emissions. The new method has been detailed in a lab-scale study published in the Wiley journal, Small. Hydrogen has long been touted as a clean future fuel and a potential solution to critical energy challenges, especially for industries that are harder to decarbonise like manufacturing, aviation and shipping. Almost all the world’s hydrogen currently comes from fossil fuels and its production is responsible for around 830 million metric tons of carbon dioxide a year*, equivalent to the annual emissions of the United Kingdom and Indonesia combined. But emissions-free ‘green’ hydrogen, made by splitting water, is so expensive that it is largely commercially unviable and accounts for just 1% of total hydrogen production globally. Lead researcher Dr Nasir Mahmood, a Vice-Chancellor’s Senior Research Fellow at RMIT, said green hydrogen production processes were both costly and relied on fresh or desalinated water. Mahmood elaborated, “We know hydrogen has immense potential as a clean energy source, particularly for the many industries that can’t easily switch over to be powered by renewables. But to be truly sustainable, the hydrogen we use must be 100% carbon-free across the entire production life cycle and must not cut into the world’s precious freshwater reserves. “Our method to produce hydrogen straight from seawater is simple, scaleable and far more cost-effective than any green hydrogen approach currently in the market. With further development, we hope this could advance the establishment of a thriving green hydrogen industry in Australia.” Splitting the difference: a catalyst for seawater To make green hydrogen, an electrolyser is used to send an electric current through water to split it into its component elements of hydrogen and oxygen. These electrolysers currently use expensive catalysts and consume a lot of energy and water – it can take about nine liters to make one kilogram of hydrogen. They also have a toxic output: not carbon dioxide, but chlorine. Mahmood continued, “The biggest hurdle with using seawater is the chlorine, which can be produced as a by-product. If we were to meet the world’s hydrogen needs without solving this issue first, we’d produce 240 million tons per year of chlorine each year – which is three to four times what the world needs in chlorine. There’s no point replacing hydrogen made by fossil fuels with hydrogen production that could be damaging our environment in a different way.” “Our process not only omits carbon dioxide, but also has no chlorine production,” he added. The new approach devised by a team in the multidisciplinary Materials for Clean Energy and Environment (MC2E) research group at RMIT uses a special type of catalyst developed to work specifically with seawater. The study, with PhD candidate Suraj Loomba, focused on producing highly efficient, stable catalysts that can be manufactured cost-effectively. “Our approach focused on changing the internal chemistry of the catalysts through a simple method, which makes them relatively easy to produce at large-scale so they can be readily synthesized at industrial scales,” noted Loomba. Mahmood added, “These new catalysts (Nitrogen-Doped Porous Nickel Molybdenum Phosphide) take very little energy to run and could be used at room temperature. While other experimental catalysts have been developed for seawater splitting, they are complex and hard to scale.” Mahmood explained the technology has the promise to significantly bring down the cost of electrolysers – enough to meet the Australian Government’s goal for green hydrogen production of $2 AU/kilogram, to make it competitive with fossil fuel-sourced hydrogen. The researchers at RMIT are working with industry partners to develop aspects of this technology. The next stage in the research is the development of a prototype electrolyzer that combines a series of catalysts to produce large quantities of hydrogen. A provisional patent application has been filed for the new method. This looks really good for areas where there is lots of sunshine or wind power with easy access to seawater. That situation just might be competitive to the fossil production sources. There would be quite an impressive investment for the power and the process system. But would it last for the decades needed to drive to good profits is a serious question. The RMIT group’s work looks like the most successful highly innovative hydrogen production system and process we’ve seen so far. Low temp and relatively low power with seemingly no water prep involved is surely a big step forward. It will be interesting to see how a “series of catalysts” might impact the production costs. |
