Deep eutectic solvents:Green multi-task agents for sustainable super green hydrogen technologies

While reliance on renewable energy resources has become a reality, there is still a need to deploy greener and more sustainable methods in order to achieve sustainable development goals. Indeed, green hydrogen is currently believed to be a reliable solution for global warming and the pollution challenges arising from fossil fuels, making it the resilient fuel of the future. However, the sustainability of green hydrogen technologies is yet to be achieved. In this context, generation of green hydrogen with the aid of deep eutectic solvents(DESs) as green mixtures has been demonstrated as a promising research area. This systematic review article covers green hydrogen generation through water splitting and biomass fermentation when DESs are utilized within the generation process. It also discusses the incorporation of DESs in fuel cell technologies. DESs can play a variety of roles such as solvent, electrolyte, or precursor;colloidal suspension and reaction medium;galvanic replacement, shape-controlling, decoration, or extractive agent;finally oxidant. These roles are relevant to several methods of green hydrogen generation, including electrocatalysis, photocatalysis, and fermentation. As such, it is of utmost importance to screen potential DES formulations and determine how they can function in and contribute throughout the green hydrogen mobility stages. The realization of super green hydrogen generation stands out as a pivotal milestone in our journey towards achieving a more sustainable form of development;DESs have great potential in making this milestone achievable. Overall, incorporating DESs in hydrogen generation constitutes a promising research area and offers potential scalability for green hydrogen production, storage,transport, and utilization.

100 W-class green hydrogen production from ammonia at a dual-layer electrode containing a Pt-Ir catalyst for an alkaline electrolytic process

Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO_(2)-free pure hydrogen.Herein,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs)with a total geometric area of 200 cm~2 on the anode side,which resulted in a hydrogen production rate of 25 L h~(-1).We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia electrolysis.Furthermore,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER).

Advanced Thermochemical Conversion Approaches for Green Hydrogen Production from Crop Residues

The huge volumes of crop residues generated during the production,processing,and consumption of farm products constitute an ecological nuisance when ineffectively managed.The conversion of crop residues to green hydrogen is one of the sustainable management strategies for ubiquitous crop residues.Production of green hydrogen from crop residue sources will contribute to deepening access to clean and affordable energy,mitigating climate change,and ensuring environmental sustainability.However,the deployment of conventional thermochemical technologies for the conversion of crop residues to green hydrogen is costly,requires long residence time,produces low-quality products,and therefore needs to be upgraded.The current review examines the conventional,advanced,and integrated thermochemical conversion technologies for crop residues for green hydrogen production.After a brief overview of the conventional thermochemical techniques,the review delves into the broad narration of advanced thermochemical technologies including catalytic pyrolysis,microwave pyrolysis,co-pyrolysis,hyropyrolysis,and autothermal pyrolysis.The study advocates the deployment of integrated pyrolysis,anaerobic digestion,pyrolysis,and gasification technologies will ensure scalability,decomposition of recalcitrant feedstocks,and generation of high grade green hydrogen.The outlook provides suggestions for future research into cost-saving and sustainable integrated technologies for green hydrogen production towards achieving carbon neutrality and a circular bio-economy.

Green Hydrogen: Perspectives and Challenges in Using the Natural Gas Network in Ceará/Brazil

Climate change, mainly caused by the use of non-renewable fuels, has raised global concerns and led to the search for less polluting energy sources, making hydrogen a promising energy alternative with the potential to contribute to changes in the energy mix of various countries through the use of technologies that enable its production and use with low or zero carbon emissions. In this context, Brazil has aroused great interest from other countries in exploring its renewable resources for the production of hydrogen (green hydrogen). In this sense, the use of natural gas pipelines and the use of hydrogen in mixtures with natural gas have become the subject of studies due to their economically viable alternative for the immediate use of this energy vector. However, there are still technical and regulatory challenges regarding the integration of hydrogen into the existing natural gas pipeline network. In this context, the present study aims to address the effects of hydrogen interaction with the structure of natural gas pipeline steel and the regulatory barriers to the use of this network for the transportation of green hydrogen, particularly in the state of Ceará/Brazil. After extensive analysis of literature and regulatory documents, it was concluded that: 1) Ceará/Brazil has strong potential to meet the demand for green hydrogen through the use of solar and wind energy sources;2) there is feasibility for the adaptation or conversion of natural gas infrastructure for the transportation of green hydrogen;3) discussions regarding the regulatory competence of green hydrogen transportation and distribution through the natural gas network in Brazil are still incipient;4) the current regulation of the natural gas industry can serve as a subsidy for the regulation of green hydrogen and natural gas transportation.

A Solar Energy System Design for Green Hydrogen Production in South-Western Nigeria, Lagos State, Using HOMER & ASPEN

Solar system design for green hydrogen production has become the most prominent renewable energy research area, and this has also actively fueled the desire to achieve net-zero emissions. Hydrogen is a promising energy carrier because it possesses more energy capacity than fossil fuels and the abundant nature of renewable energy systems can be utilized for green hydrogen production. However, the design of an optimized electrical energy system required for hydrogen production is crucial. Solar energy is indeed beneficial for green hydrogen production and this research designed, discussed, and provided high-level research on HOMER design for green hydrogen production and deployed the energy requirement with ASPEN Plus to optimize the energy system, while also incorporating fuzzy logic and PID control approaches. In addition, a promising technology with a high potential for renewable hydrogen energy is the proton exchange membrane (PEM) electrolyzer. Since its cathode (hydrogen electrode) may be operated over a wide range of pressure, a control process must be added to the system in order for it to work dynamically efficiently. This system can be characterized as an analogous circuit that consists of a resistor, capacitor, and reversible voltage. As a result, this research work also explores the Fuzzy-PID control of the PEM electrolysis system. Both the PID and Fuzzy Logic control systems were simulated using the control simulation program Matlab R2018a, which makes use of Matlab script files and the Simulink environment. Based on the circuit diagram, a transfer function that represents the mathematical model of the plant was created, and the PEM electrolysis control system is determined to be highly significant and applicable to the two control systems. The PI controller, however, has a 30.8% overshoot deficit, but when the fuzzy control system is compared to the PID controller, it is found that the fuzzy control system achieves stability more quickly, demonstrating its benefit over PID.

Towards the insights into the deactivation behavior of acetylene hydrogenation catalyst

A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;finally, the deactivation behavior of the commercial catalyst for acetylene hydrogenation were studied. The influence of various possible deactivation factors on the catalytic performance was elucidated via detailed structural characterization, surface composition analysis, and activity evaluation.The results showed that green oil, carbon deposit and sintering of active metal were the main reasons for deactivation, among which green oil and carbon deposit led to rapid deactivation, while the activity could be recovered after regeneration by high-temperature calcination. The sintering of active metal components was attributed to the high-temperature regeneration in hydrothermal conditions, which was slow but irreversible and accounted for permanent deactivation. Thus, optimizing the regeneration is expected to extend the service life of the commercial catalyst.

Hydrogen peroxide and applications in green hydrocarbon nitridation and oxidation

Basic organic chemicals and high value–added products are mainly produced by hydrocarbon nitridation and oxidation.However,several drawbacks limit the application of the traditional oxidation and nitridation technologies in the future,such as complex processes,poor intrinsic safety,low atom utilization,and serious environmental pollution.The green nitridation and oxidation technologies are urgently needed.Hydrogen peroxide,a well–known green oxidant,is widely used in green hydrocarbon oxidation and nitridation.But its industrial production in China adopts fixed–bed technology,which is fall behind slurry–bed technology adopted by advanced foreign chemical companies,limiting the development of hydrogen peroxide industry and green hydrocarbon nitridation or oxidation industry.This article reviews the industrial production technologies of hydrogen peroxide and basic organic chemicals such as caprolactam,aniline,propene oxide,epichlorohydrin,phenol,and benzenediol,especially introduces the green production technologies of basic organic chemicals related with H_(2)O_(2).The article also emphasis on the efforts of Chinese researchers in developing its own slurry–bed technology of hydrogen peroxide production,and corresponding green hydrocarbon nitridation or oxidation technologies with hydrogen peroxide.Compared with traditional nitridation or oxidation technologies,green production technologies of caprolactam,propene oxide,epichlorohydrin,and benzenediol with hydrogen peroxide promote the nitrogen atom utilization from 60%to near 100%and the carbon atom utilization from 80%to near 100%.The waste emissions and environmental investments are reduced dramatically.Technological blockade against the green chemical industry of China are partially broken down,and technological upgrade in the chemical industry of China is guaranteed.

Can Brazil Become a Green Hydrogen Powerhouse?

This paper assesses the feasibility of green hydrogen production in Brazil. By green hydrogen, it is meant the hydrogen produced by the electrolysis of water by consuming electricity produced by renewable sources. The country has large areas with high solar irradiation and favorable wind velocities that help to make wind power and solar PV economical alternatives. Other factors include lower investments and lower grid integration cost with respect to global average, because of the large share of hydropower. As known, hydro plants respond well to the short-term variability of renewable production. Local regulations also incentivize renewable energy. For example, it is possible, according to market rules, for a hydrogen producer to sign a financial Power Purchase Agreement (PPA) contract with a producer or trader to secure a firm, renewable energy supply for the electrolysis process. This market-driven factor, and other key factors, such as low price of electricity, are considered in an economic feasibility model. Results from this model suggest that Brazil could become a green hydrogen powerhouse for the internal market and potential exports to Germany and other European countries.

Potential for Green Hydrogen Production from Biomass, Solar and Wind in Togo

Potential of green hydrogen producing from biomass, solar and wind in Togo has been performed. The availability of these three resources has been depicted with maps showing them per cantons in Togo, thus, by using the datasets from ESA Biomass Climate Change Initiative, the global solar atlas and the global wind atlas. The conversions rates used were: for solar resource, 3% of land was allocated for the analysis after removing the exclusions with a conversion rate of 52.5 kWh/kg of hydrogen;for biomass hydrogen, the conversion rate of 13.4 kg BS/kg H2 was assumed. Wind resources at 50 m above ground were not sufficient to evaluate the potential as it is lower than class 3 winds. QGIS version 3.6.4 and R version 4.0.4 were used. Results showed that biomass is the leading resource for producing green hydrogen from renewable energy resources;with good impact in these two cantons: Bassar, Gobe/ Eketo/Gbadi N’Kugna. However, this resource is still decreasing and in some cantons it is null.

20 ppm Anhydrous Ammonia Odor Agent Proposed for Hydrogen Fuel for Safe Detection of Leaks

Preferably 20 ppm anhydrous ammonia (NH3) is proposed to be added to hydrogen fuel (H) made from renewable energy sources (green hydrogen), so that H leaks may be easily detectable by smell, but not dangerously toxic. Including this odor agent, would allow H to be distributed safely in pipes, as required by law, and it would allow H to be safely stored, transported, and exported for sale, and widely commercialized. Further research is suggested to identify optimum pressure, temperature, and automated technique for injecting NH3 into H, and to chart the minimum concentration needed, as a function of temperature and humidity. An application to make hypersonic H burning aircraft safer for ground maintenance crews is proposed. An ability to make, store and distribute H, made from local sources of renewable energy, would reduce a need for fossil fuels, especially in poor, remote communities, where it could improve their economy by creating an export product for sale, while reducing pollution.

Production of Green Hydrogen by Efficient and Economic Electrolysis of Water with Super-alloy Nanowire Type Electrocatalysts

Green hydrogen production from the electrolysis of water has good appli­cation prospect due to its renewability.The applied voltage of 1.6-2.2V is required in the traditional actual water electrolysis process although the the­oretical decomposition potential of electrolyzing water is 1.23V.The high overpotential in the electrode reaction results in the high energy-consuming for the water electrolysis processes.The overpotentials of the traditional Ru,Ir and Pt based electrocatalysts are respectively 0.3V,0.4V and 0.5V,furthermore use of the Pt,Ir and Ru precious metal catalysts also result in high cost of the water electrolysis process.For minimizing the overpoten­tials in water electrolysis,a novel super-alloy nanowire electrocatalysts have been discovered and developed for water splitting in the present pa­per.It is of significance that the overpotential for the water electrolysis on the super-alloy nanowire electrocatalyst is almost zero.The actual voltage required in the electrolysis process is reduced to 1.3V by using the novel electrocatalyst system with zero overpotential.The utilization of the su­per-alloy nanowire type electrocatalyst instead of the traditional Pt,Ir and Ru precious metal catalysts is the solution to reduce energy consumption and capital cost in water electrolysis to generate hydrogen and oxygen.

氢产业链发展的路径分析

碳达峰、碳中和战略的提出为我国各行业绿色低碳转型指明了方向,绿色氢能源有望在交通、化工、发电等多个领域发挥重要作用,推动氢产业发展可成为我国实现双碳目标的有效途径。本文在对美国、欧盟、日本和中国近年来氢产业发展情况进行比较与分析的前提下,提出了中国氢产业链的发展路径。文中指出,我国需要在借鉴发达国家氢产业发展政策的基础上,立足本国国情,统筹谋划构建从制氢、储运、加氢站建设到多场景应用的产业链。综合考虑我国的资源分布情况,加大绿氢产业布局,依据绿氢的绿色能源、绿色材料以及绿色原料的多元属性,推动氢能在交通、化工、冶金、发电等多场景的高效利用,同时我国要加强国际合作,联合研发相关新型技术与基础设施,制定涉氢国际标准,统筹兼顾氢产业经济发展与应对全球气候变暖的双重目标。

风光制氢合成氨系统的多时段可调度域分析

为直观描述风光发电制氢合成氨(power-to-ammonia,P2A)系统的柔性负荷调节潜力,计及制氢、合成氨化工过程的负载调控特性,基于动态规划思想和计算几何理论,提出其多时段可调度域(multi-stagedispatchableregion,MSDR)的刻画方法。所提方法将多时段间相互耦合的鲁棒约束变换为“氢缓冲罐贮量–合成氨产率”状态空间中的确定性多面体约束,使得对于可调度域内的任意系统状态,均存在满足完整调度过程安全约束的“制氢流量–氨产率爬坡速率”控制序列,从而实现P2A系统可调度能力的可视化。所提MSDR模型可进一步用于构造多时段鲁棒优化调度,在保证可行性的前提下优化P2A系统的经济收益。最后,基于内蒙古自治区某在建示范工程构造算例,验证所提方法的有效性。

适用可再生能源不确定特性的合成氨多稳态柔性工艺技术

双碳背景下,风光可再生能源发电是能源发展的重要方向,“绿氢”由于其长周期存储和零碳特征,可以有效解决风光电力消纳的难题,有望与电能一同成为未来能源体系的两大支柱。但是由于氢气自身特性和氢脆造成的材料瓶颈,“绿氢”发展遇到制储运多环节安全性与经济性挑战。绿电制氢制氨的“电制绿氨”路径被认为是解决“绿电”“绿氢”技术经济困局的重要途径之一。针对风光资源的不确定性,分析了基于合成氨“哈-博”工艺多种解决方案的优劣,提出了多稳态柔性“电制绿氨”工艺模式以解决“源网氢氨”复杂技术特征耦合下的设计、装置和运行问题;研究了多稳态柔性“电制绿氨”工艺的系统性技术架构、整定经济运行负荷与运行周期的最优化方法;开发了电氢氨一体化数字仿真模型,计及电力约束、资源波动、氢氨需求、系统运行效率和可靠性等因素,对全场景、全流程下的“电制绿氨”进行协同优化,形成了一套面向动态运行的绿电耦合化工的设计方法;研究了催化剂结构性能调优与合成塔内件结构的优化方法,开发了复杂变工况条件的催化剂宏观动力学模型,以及电氢氨一体化协同调度与智能控制技术。多稳态柔性“电制绿氨”工艺实现了合成氨经济运行负荷在30%~110%,负荷调节速率在0.5~1.0%/min,支持日、班,及班内多时域负荷调节要求,30%~110%负荷运行下单位合成氨综合能耗均优于GB 21344—2015《合成氨单位产品能源消耗限额》的标杆值。

考虑绿色氢能证书和水电制氢的综合能源系统优化运行

利用清洁能源发电富余电力电解水制氢,绿色氢能实现了生产源头的二氧化碳零排放,在全球能源转型中扮演着重要角色。针对绿色氢能证书市场机制不健全等问题,该文提出一种考虑绿色氢能证书组合双向拍卖和水电制氢的综合能源系统优化运行方法。首先,为解决园区内绿色氢能证书价格和数量匹配不均衡的问题,提出绿色氢能证书组合双向拍卖(combinatorial double auction,CDA)交易机制竞价模型;其次,建立含水电制氢的综合能源系统优化模型,并将绿色氢能证书组合双向拍卖机制引入其中;最后,以某省含水电制氢的综合能源系统为例进行仿真分析,结果表明所提模型不仅能有效提高综合能源系统(integrated energy system,IES)的运行经济性,也能提升可再生能源的消纳量。

双碳目标下的氨燃料航空动力研究进展及展望

为了获得氨燃料航空动力应用潜力评价,本文综述了氨燃料的绿色制取方法、氨燃料燃烧特性的研究成果以及氨航空发动机设计过程中可能存在的技术问题和相应的解决方案。综合已有研究成果,本文认为氨燃料航空发动机具有非常广阔的应用前景,采用氨氢混合燃烧在未来有望成为氨燃料航空动力系统的优选方案。

我国工业领域绿氢发展应用现状与前景分析

以可再生能源制氢替代化石能源制氢是未来工业领域实现绿色低碳转型的主要路径之一,我国水电解制氢技术以碱性电解技术为主,适合波动性新能源的PEM电解技术将有较好的发展前景。从经济性和碳排放两方面对绿氢的竞争力进行了分析,认为目前我国绿氢成本还较高,未来随着新能源电力成本的下降以及碳排放成本的上升,绿氢将逐渐在我国能源体系中发挥重要作用。重点介绍了绿氢发展现状及趋势,分析了绿氢行业存在的主要问题,指出随着我国绿氢化工项目的加速推进,在行业脱碳进程中应重点考虑不要盲目加快绿氢的工业应用进程,需要国家层面在绿氢制备和工业消纳领域出台相应的支持政策,同时建议加快相关标准体系的建设进度。

碳中和目标时代绿色氢能发展技术路线研究

大力发展氢能特别是绿色氢能是推动绿色低碳转型和新能源发展、实现碳中和目标的重要举措。论述了氢能的开发利用途径、氢能在“源网荷储”新型电力系统建设中的重要价值以及“风光氢储”的主要形式及重要载体;重点梳理了碱性电解水制氢技术、质子交换膜电解水制氢技术、固体氧化物电解水制氢技术和阴离子交换膜电解水制氢技术的能耗、成本、碳排放、能源效率、产业化程度、单机规模、技术瓶颈与发展方向;总结了氢能产业面临的技术难题与挑战,并提出了氢能产业的技术路线与发展趋势。

油气行业可再生能源制氢技术进展与前景展望

利用可再生能源制氢,是油气企业推动能源结构优化升级与深度脱碳的重要途径。油气企业近年通过全产业链技术研究与示范应用,积极推动氢能产业高效益、规模化发展。文章研究对比了碱性电解水制氢(ALK)、质子交换膜制氢(PEM)和固体氧化物电解制氢(SOEC)等技术的优势与挑战,分析了国内外代表性油气公司在制氢产业和项目方面的布局规划。中国石油围绕绿氢产业链与制氢技术链,持续攻关符合自身特色应用场景的可再生能源制氢技术及配套系统,涵盖基础研究到项目示范,在高效率电极催化剂材料、电解槽系统优化、氢电耦合系统、大规模大容量制氢装置、固体氧化物电解制氢技术、太阳能光解水制氢技术等领域取得系列创新成果。结合我国油气企业制氢技术特点、场景特色与项目现状,对未来可再生能源制氢领域发展提出建议和展望。

绿氢产业链安全风险与防控技术研究进展

发展大规模绿氢产业是推动我国能源结构转型和实现“双碳”目标的战略选择。利用可再生能源制备绿氢,将规模性替代化石能源制氢,有效降低能源生产消费过程碳排放,支撑构筑新型能源体系。绿氢产业链主要包括上游绿氢制取、中游绿氢储运和下游绿氢应用。通过分析绿氢制取、储存、运输及应用过程的技术发展现状,总结了绿氢生产各环节存在的安全风险;并基于系统安全及保护层安全防护理念,从技术、标准、政策法规、创新平台等方面提出了相应的风险防控建议,为筑牢大规模绿氢利用安全基础,保障绿氢产业安全高质量发展提供参考思路。