Ecological and Economic Evaluation of Hydrogen Production by Different Water Electrolysis Technologies

The economic and ecological production of green hydrogen by water electrolysis is one of the major challenges within Carbon2Chem® and other power-to-X projects. This paper presents an evaluation of the different water electrolysis technologies with respect to their specific energy demand, carbon footprint and the forecast production costs in 2030. From a current perspective alkaline water electrolysis is evaluated as the most favorable technology for the cost-effective production of low-carbon hydrogen with fluctuating renewables.     

Alkaline Water Electrolysis: Efficient Bridge to CO2-Emission-Free Economy

Water electrolysis is a key technology to realize sector coupling and renewables integration. To establish CO₂-free or -reduced value chains as well as carbon capture and utilization, “green hydrogen” is the essential element, serving as fuel, energy carrier, and feedstock for “green chemicals”. As a well-developed technology, alkaline water electrolysis (AWE) enables industrial scale hydrogen production in high purity. The electrolyzers are highly dynamic in operation and can also serve as primary control reserve, thus further stabilizing the power grid.     

电解水制氢系统安全设计

针对氢气制备及纯化,根据氢气的理化和火灾危险特性,分析电解水制氢系统中的潜在危险因素,提出安全设计思路.     

电解水Ni-S电极合金的研究

采用电沉积法在镍网上制备Ni-S合金,在固定的溶液组成、电镀的电流密度和温度的条件下,研究电沉积时间对电极析氢过电位的影响。试验结果表明,与未镀合金的电极相比,Ni-S合金电极的析氢过电位可降低130mV,具有很好的析氢反应活性。     

Analysis and Study on Polarization during Water Electrolysis Hydrogen Production

During a time of high energy consumption, water electrolysis is currently one of the alternative energy sources. At low voltages and low concentrations where activation and concentration polarizations are most dominant, the polarization effects are most significant and the electrolysis is most inefficient. Whereas at high voltages and high concentrations, the activation and concentration polarizations will quickly diminish, producing better electrolysis results. We can see from the empirical data that when the electrode distance is 2 mm and the electrolyte is 30 wt% KOH, a shorter electrode distance with an appropriate actual electrolysis voltage will produce lower polarization impedance values and hence the best efficiency in electrolysis. This study used electrochemical impedance spectroscopy (EIS) to detect relevant data on resistance. Applying it in the field of water electrolysis can provide another method to detect and clarify the phenomenon of polarization and impedance.     

水电解制氢槽隔膜用聚苯硫醚纤维的耐碱性能

聚苯硫醚(PPS)纤维具有良好的物理和化学性能,将成为最有前景的碱性水电解制氢槽隔膜原料之一。通过对PPS短纤维、长丝的碱减量和强力损失率的测试和分析,表明PPS纤维具有良好的耐碱性能,能够满足碱性水电解槽用隔膜的性能要求。     

电解制氢电极材料的研究进展

氢能是一种高效、洁净的二次能源,电解水是实现大规模制氢的重要手段。镍合金作为碱性电解水阴极有着价格低廉、析氢过电位低的特征。文章就其合成方法、析氢反应催化性能、反应机理做了简要的评叙和分析。     

粉煤气化同水电解制氢合成甲醇工艺技术综述(上)

采用粉煤气化同水电解制取H2／CO摩尔比为2的合成气合成甲醇,CO可全部利用,CO2为零排放,避免了CO2对大气产生温室效应的危害。论述了粉煤加压纯氧气化工艺的特点、工业化过程、生产操作参数和主要设备。介绍了水电解制氢工艺的开发历程、工艺技术和工业化电解槽的设计,阐述了现代水电解技术的改进和研究进展状况。     

Design of a Zero‐Gap Laboratory‐Scale Polymer Electrolyte Membrane Alkaline Water Electrolysis Stack

The development of a zero‐gap alkaline water electrolysis stack based on a heterogeneous anion‐selective polymer electrolyte membrane is reported. A bipolar electrode arrangement was selected as the most appropriate one. The design was targeted to verify the suitability of the membrane electrode assembly design and the functionality of the gas separator system developed together with the purity of the gases produced. The influence of various operational regimes on the purity of the gases was investigated. Last, but not least, a validation of the mathematical model to be used for scale‐up of the cell, foreseen for the next step of the project, was performed.     

Experimental Study of Plasma Under-liquid Electrolysis in Hydrogen Generation

The application and characteristics of relatively big volume plasma produced with cathodic glow discharges taking place across a gaseous envelope over the cathode which was dipped into electrolyte in hydrogen generation were studied. A critical investigation of the influence of methanol concentration and voltage across the circuit on the composition and power consumption per cubic meter of cathode liberating gas was carried out. The course of plasma under-liquid electrolysis has the typical characteristics of glow discharge electrolysis. The cathode liberating gas was in substantial excess of the Faraday law value. When the voltage across the circuit was equal to 550 V, the volume of cathodic gas with sodium carbonate solution was equal to 16.97 times the Faraday law value. The study showed that methanol molecules are more active than water molecules. The methanol molecules were decomposed at the plasma-catholyte interface by the radicals coming out the plasma mantle. Energy consumption per cubic meter of cathodic gases (WV) decreased while methanol concentration of the electrolytes increased. When methanol concentration equaled 5% (j), WV was 10.381′103 kJ/m3, less than the corresponding theoretic value of conventional water electrolysis method. The cathodic liberating gas was a mixture of hydrogen, carbon dioxide and carbon monoxide with over 95% hydrogen, if methanol concentration was more than 15% (j). The present research work revealed an innovative application of glow discharge and a new highly efficient hydrogen generation method, which depleted less resource and energy than normal electrolysis and is environmentally friendly.     

膜电解法在处理酸性含镍废水中的研究

针对人造金刚石厂的含镍废水,在常规电解方法的基础上,采用膜电解法对该含镍废水的处理和金属镍回收进行了研究,通过对不同条件下的阴、阳膜及组合方式的效果和优缺点进行比较。结果表明单阴膜法在处理pH值为0.5～1.0,初始镍的质量浓度为1000～2000mg/L的废水应用中有更好的处理效果。当电解的电流150mA,电压5V时,电解时间控制在8～10h,10h后离子交换富集,循环使用,其平均电流效率为78.4%,金属镍的回收率达到79.3%且纯度较高。     

油脂皂化工业污水电解处理工艺与效果研究

介绍了油脂皂化工业污水的组成、处理目标及其难度,报告了电解处理工艺与效果,探讨了该方法的机理和应用前景。实验表明:该方法可使污水COD降低90％以上。     

Water electrolysis in the presence of an ultrasonic field

The energy efficiency of water electrolysis has been considerably improved in the presence of an ultrasonic field. This was demonstrated by measuring the cell voltage, efficiency and energy consumption of the generated gas from the electrolysis. These measurements were carried out in alkaline solution using linear sweep voltammetry (LSV) and galvanostatic polarization techniques. A large reduction of the cell voltage was achieved under the ultrasonic field, especially at high current density and low electrolyte concentration. With the same current density, the cell voltage difference with and without the ultrasonic field fell as the concentration of the electrolyte was increased. The efficiency of H₂ generation was improved at a range of 5-18% at high current density in the ultrasonic field but the efficiency of O₂ generation fell a little due to the difference in the behavior of the gas bubbles. The energy saving for H₂ production by using the ultrasonic field was about 10-25% for a certain concentration of the electrolyte when a high current density was used. On the other hand, the energy consumption for O₂ production with and without the ultrasonic field was almost the same.     

铁炭内电解法处理染料废水的研究

采用铁屑-活性炭内电解法作为光合细菌处理实际染料废水的预处理方法,考察了3个主要影响因素(铁炭比、停留时间、初始pH值).结果表明,最佳的处理条件为:铁炭比为7∶3,pH值为5,停留时间为60 min.在上述最佳处理条件下,对初始CODCr为6 790 mg/L的染料废水处理效率可以达到66.1%,并且废水经预处理后可生化性得到大大提高,有利于后续生化处理的进行.     

内电解法处理染料生产废水试验研究

利用铁炭在水中发生的内电解过程可以有效地去除染料生产废水的色度,并提高污水的可生化知识性,同时对CODcr也有一定的去除效果。试验结果表明,进水CODcr为1200mg/L的染料废水,经内电解法处理后,脱色率可达75%以上,CODcr去除率也可达到45%左右,该法对CODcr的处理效果比单纯的石灰乳中和混凝沉淀法要高10%以上。     

粉煤气化同水电解制氢合成甲醇工艺技术综述(下)

采用粉煤气化同水电解制取H2／CO摩尔比为2的合成气合成甲醇,CO可全部利用,CO2为零排放,避免了CO2对大气产生温室效应的危害。论述了粉煤加压纯氧气化工艺的特点、工业化过程、生产操作参数和主要设备。介绍了水电解制氢工艺的开发历程、工艺技术和工业化电解槽的设计,阐述了现代水电解技术的改进和研究进展状况。     

电解法制备高纯四甲基氢氧化铵的研究

用电解 电渗析法 ,以四甲基氯化铵为原料 ,石墨为阳极 ,不锈钢为阴极 ,采用 8A/dm2 的电流密度 ,制得高纯度的四甲基氢氧化铵 ,电流效率为 79.4% ,同时研究了影响制备四甲基氢氧化铵纯度和电流效率的因素。     

熔盐电解法制备元素硼粉

介绍了熔盐电解法制备元素硼粉的方法,讨论并比较了各体系的长处与不足.     

三维催化电解法处理丙烯腈废水的探讨

丙烯腈是重要的化工原料,在合成纤维、塑料等领域有着广阔的应用前景。但其生产过程污染严重,污水有毒有害,治理难度高。采用传统污水处理方式处理此类污水效果不佳。以三维催化电解法为主要思路,研究替代传统生化污水处理方式处理丙烯腈废水的可行性及相关技术参数,探索了处理此类石油化工污水的新途径。     

应用存水率与水驱指数评价油田水驱开发效果

对于低渗透油藏,边底水不活跃,天然能量不能得到及时的补充,因此开发难度较大。注水开发能够及时补充地层压力,是目前针对低渗透油藏的主要开发技术。而注水开发油田开发效果的评价对于进一步改善开发效果,提高最终采收率尤为重要。给出了两种评价指标,存水率以及水驱指数的理论计算公式,并分别分析其与含水率的变化关系,指出理论值与实际值产生差异的原因。以X油田为例,应用两种指标进行开发效果分析。