scholarly journals Hydrogen and Oxygen Production via Water Splitting in a Solar-Powered Membrane Reactor—A Conceptual Study

Hydrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 18-32
Author(s):  
Silvano Tosti ◽  
Alfonso Pozio ◽  
Luca Farina ◽  
Alessia Santucci
Keyword(s):  
Water Splitting ◽  
Membrane Reactor ◽  
Practical Interest ◽  
Reaction Products ◽  
Critical Data ◽  
A Value ◽  
Reaction Conversion ◽  
Water Feed ◽  
Solar Powered ◽  
Conceptual Study

Among the processes for producing hydrogen and oxygen from water via the use of solar energy, water splitting has the advantage of being carried out in onestep. According to thermodynamics, this process exhibits conversions of practical interest at very high temperatures and needs efficient separation systems in order to separate the reaction products, hydrogen and oxygen. In this conceptual work, the behavior of a membrane reactor that uses two membranes perm-selective to hydrogen and oxygen is investigated in the temperature range 2000–2500 °C of interest for coupling this device with solar receivers. The effect of the reaction pressure has been evaluated at 0.5 and 1 bar while the permeate pressure has been fixed at 100 Pa. As a first result, the use of the membrane perm-selective to oxygen in addition to the hydrogen one has improved significantly the reaction conversion that, for instance, at 0.5 bar and 2000 °C, moves from 9.8% up to 18.8%. Based on these critical data, a preliminary design of a membrane reactor consisting of a Ta tubular membrane separating the hydrogen and a hafnia camera separating the oxygen is presented: optimaloperating temperature of the reactor results in being around 2500 °C, a value making impracticable its coupling with solar receivers even in view of an optimistic development of this technology. The study has verified that at 2000 °C with a water feed flow rate of 1000 kg h−1 about 200 and 100 m3 h−1 of hydrogen and oxygen are produced. In this case, a surface of the hafnia membrane of the order of hundreds m2 is required: the design of such a membrane device may be feasible when considering special reactor configurations.

Novel CO2-Thermic Oxidation Process with Mg-Based Intermetallic Compounds and Its Application to Energy Storage Materials

2018 ◽  
Author(s):  
Younghwan Cha ◽  
Jung-In Lee ◽  
Panpan Dong ◽  
Xiahui Zhang ◽  
Min-Kyu Song
Keyword(s):  
Intermetallic Compounds ◽  
Oxidation Process ◽  
Value Added ◽  
Energy Storage Materials ◽  
Reaction Products ◽  
Materials Synthesis ◽  
Energy Materials ◽  
A Value ◽  
Carbon Coated ◽  
Novel Strategy

A novel strategy for the oxidation of Mg-based intermetallic compounds using CO<sub>2</sub> as an oxidizing agent was realized via simple thermal treatment, called ‘CO2-thermic Oxidation Process (CO-OP)’. Furthermore, as a value-added application, electrochemical properties of one of the reaction products (carbon-coated macroporous silicon) was evaluated. Considering the facile tunability of the chemical/physical properties of Mg-based intermetallics, we believe that this route can provide a simple and versatile platform for functional energy materials synthesis as well as CO<sub>2</sub> chemical utilization in an environment-friendly and sustainable way.

scholarly journals Fully Solar-Powered Uninterrupted Overall Water-Splitting Systems

2019 ◽  
Vol 29 (9) ◽  
pp. 1808889 ◽  
Author(s):  
Qichong Zhang ◽  
Bing He ◽  
Lei Tang ◽  
Zhenyu Zhou ◽  
Lixing Kang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Overall Water Splitting ◽  
Solar Powered

scholarly journals SIMULTANEOUS METHYL ESTER PRODUCTION AND CAROTENE RECOVERY FROM CRUDE PALM OIL USING MEMBRANE REACTOR

2019 ◽  
Vol 81 (2) ◽  
Author(s):  
I Gusti Bagus Ngurah Makertihartha ◽  
Khoiruddin Khoiruddin ◽  
Eryk Bone Pratama Nabu ◽  
Putu Teta Prihartini Aryanti ◽  
I Gede Wenten
Keyword(s):  
Methyl Ester ◽  
Palm Oil ◽  
Membrane Reactor ◽  
Membrane Separation ◽  
Acid Methyl Ester ◽  
Dry Process ◽  
Reaction Conversion ◽  
Biodiesel Quality ◽  
Separation Performances ◽  
Treatment Step

Fatty acid methyl ester (FAME) or biodiesel¸ which is considered as an alternative renewable fuel is usually produced via transesterification reaction of triglyceride from vegetable oil. Generally, there are two major challenges in the production of biodiesel i.e., reversible reaction of transesterification and immiscibility between oil and alcohol. Membrane reactor (MR), which combines reaction and separation, is an alternative process to overcome those challenges. The aim of the integrated reaction-separation process is to shift the equilibrium reaction, and to achieve a higher reaction conversion. The methyl ester that is produced may be separated to meet the biodiesel quality standards. FAME purification using membrane can be conducted without water washing (dry process), and this is interesting as the associated wastewater treatment step is eliminated. Another attractive feature of MR in esterification process is carotenoid recovery which is beneficial to improve the efficiency of the process. Several studies have indicated the efficacy of carotenoids recovery from methyl ester mixture. This paper reviews the use of MR for palm oil esterification. Membrane separation performances in methyl ester purification are also discussed. In addition, the potential of carotene recovery during esterification process is highlighted. 

A novel membrane reactor for separating hydrogen and oxygen in photocatalytic water splitting

2011 ◽  
Vol 382 (1-2) ◽  
pp. 291-299 ◽  
Author(s):  
Szu-Chun Yu ◽  
Chao-Wei Huang ◽  
Chi-Hung Liao ◽  
Jeffrey C.S. Wu ◽  
Sun-Tang Chang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Membrane Reactor ◽  
Photocatalytic Water Splitting

scholarly journals Hydrogenation of Maltose in Catalytic Membrane Reactor for Maltitol Production

2018 ◽  
Vol 156 ◽  
pp. 08008 ◽  
Author(s):  
I.G.B.N. Makertihartha ◽  
Khoiruddin ◽  
Ahmad N. Hakim ◽  
P.T.P. Aryanti ◽  
I.G. Wenten
Keyword(s):  
Membrane Reactor ◽  
Ceramic Membrane ◽  
Operating Pressure ◽  
Catalytic Membrane ◽  
Catalytic Membrane Reactor ◽  
Batch Mode ◽  
Food Industries ◽  
Reaction Conversion ◽  
Preliminary Study ◽  
Sugar Replacement

Maltitol is one of the low-calorie sweeteners which has a major role in food industries. Due to its characteristics of comparable sweetness level to sucrose, maltitol can be a suitable sugar replacement. In this work, catalytic membrane reactor (CMR) was examined in maltitol production through hydrogenation of maltose. Commercial ceramic membrane impregnated with Kalcat 8030 Nickel was used as the CMR. The reaction was conducted at a batch mode operation, 95 to 110°C of temperature, and 5 to 8 bar of pressure. In the range of working conditions used in this study, up to 47% conversion was achieved. The reaction conversion was significantly affected by temperature and pressure. Results of this preliminary study indicated that CMR can be used for hydrogenation of maltose with good performance under a relatively low operating pressure.

scholarly journals Typical Mistakes in Forensic Handwriting Analysis of Copies of Handwritten Entries

2019 ◽  
Vol 14 (1) ◽  
pp. 97-105
Author(s):  
G. V. Cherepenko
Keyword(s):  
Forensic Science ◽  
Peer Review ◽  
Practical Interest ◽  
European Network ◽  
Handwriting Analysis ◽  
Close Attention ◽  
A Value ◽  
Value Judgement

The growing volume of forensic handwriting examinations of handwritten requisites copies entails the need to determine the range of the most typical mistakes made by experts in examination of these objects. The article gives examples of the most common mistakes in expert reports, the origin of some is analyzed. The system of internal and external forms of peer review of the ENFSI (The European Network of Forensic Science Institutes) experts’ conclusions is reviewed. To avoid most of mistakes described in the article the author proposes to follow relevant methodological references, to pay close attention to the quality of the examined object, to adhere strictly to all intermediate stages of examination. Also, to use internal and external peer review of conclusions as a form of control more effectively. The information contained in the article can be of practical interest when both reviewing conclusions in state expert institutions and preparing a value judgement regarding an expert/specialist conclusion.

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