scholarly journals Hydrogen: Technologies, Policies and Challenges

2012 ◽  
Vol 260-261 ◽  
pp. 28-33
Author(s):  
Jun Zhang ◽  
Lu Cheng Ji ◽  
Bo Jin

Hydrogen energy has been considered as a clean alternative energy source substituting fossil fuels. Many countries consider it as the ultimate solution to the energy and environmental problems, even draw up the blueprint of “hydrogen economy” and heavily invest for research and development. However, after decades of research, the hydrogen energy technologies are still being prospective and explored, and haven’t been put into large scale production by now. This article begins with expatiation on the essence of hydrogen energy, makes analysis of various big challenges for hydrogen energy technologies, and reaches the conclusion that we should hold the rational and cautious attitude towards hydrogen energy source because the transition to hydrogen economy of unclear prospect must pay a very high cost, which is unbearable for the social and economic development status of developing countries.

Author(s):  
Yuting Luo ◽  
Zhiyuan Zhang ◽  
Fengning Yang ◽  
Jiong Li ◽  
Zhibo Liu ◽  
...  

Large-scale production of green hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious...


2021 ◽  
Vol 257 ◽  
pp. 03008
Author(s):  
Muxin Hu ◽  
Dichen Zhao ◽  
Qiuchi Jin ◽  
Hanrui Li ◽  
Wenmin Wang

In recognition of the increasing demand of energy and the worsening environmental problems linked with fossil fuels usage, algal biofuel has been proposed as one of the alternative energy sources. It has become one of the hottest topics in renewable energy field in the new century, especially over the past decade. In this review, we summarized the characteristics of different types of algae biofuels. Besides, an in-depth evaluation of the systematic cultivation and practical application of algae have been conducted. Although algal biofuel has a great potential, its unacceptably high cost limits the large-scale industrialization. In order to resolve such restrictions, feasible methods of improving the large scale production and practical application of algal biofuels are proposed. Future efforts should be focused not only on the cost reduction and innovation techniques, but also towards high value by-products to maximize economic benefits. Our results are dedicated to provide valuable references for subsequent research and guidelines on algae biofuels field.


Author(s):  
V. V. Mitin ◽  
A. A. Kokh

The article is devoted to the current state and prospects of production development of main material — polycrystalline silicon (polysilicon) which is used in the manufacture of products for micro and power electronics and photovoltaics. The article includes polycrystalline silicon market dynamics analysis. It is noted that the increase in polysilicon output is primarily connected to the growing needs of photovoltaics and the global trend of transition to renewable, alternative energy. It is assumed that the annual increase in the output of polysilicon will reach a level of 10−15 % or more. There are several facts that are important for the intensive development of photovoltaics. They include level of polycrystalline silicon technology and the availability of this material for large−scale production of highly efficient solar cells. According to forecasts, the main technology used in the industry based on «Siemens Process» will remain dominant in the foreseeable period of time. LLC «Kremniytehnoprom» is developing a modern polysilicon production project based on the original designs and modernization of «Siemens Process». It is planned to be created in Russia with the involvement of leading German specialists and enterprises (SPSC GmbH, GEC GmbH). The project provides maximum safety of production, despite the potential risks inherent in technology. First of all it is ensured by guarantees of hardware−technological schemes performance, reliability of the equipment and design solutions in general, as well as by a set of emergency protections. Toxic production waste will be processed into safe substances — targeted products for sale. The created enterprise will ensure the optimization of key indicators for competitive production: the price of polysilicon, production volumes, specific capital investments and current unit costs.


2021 ◽  
Vol 12 ◽  
Author(s):  
Joshua A. Schultz ◽  
Heather D. Coleman

A potential method by which society's reliance on fossil fuels can be lessened is via the large-scale utilization of biofuels derived from the secondary cell walls of woody plants; however, there remain a number of technical challenges to the large-scale production of biofuels. Many of these challenges emerge from the underlying complexity of the secondary cell wall. The challenges associated with lignin have been well explored elsewhere, but the dicot cell wall components of hemicellulose and pectin also present a number of difficulties. Here, we provide an overview of the research wherein pectin and xylan biosynthesis has been altered, along with investigations on the function of irregular xylem 8 (IRX8) and glycosyltransferase 8D (GT8D), genes putatively involved in xylan and pectin synthesis. Additionally, we provide an analysis of the evidence in support of two hypotheses regarding GT8D and conclude that while there is evidence to lend credence to these hypotheses, there are still questions that require further research and examination.


2005 ◽  
Vol 20 (12) ◽  
pp. 3180-3187 ◽  
Author(s):  
Jim Ohi

This overview will describe briefly key segments of the hydrogen energy cycle from production using various feedstocks to its end use in fuel cells to generate electrical and thermal energy. The paper will also discuss the larger societal context, the so-called “hydrogen economy,” in which such production and use of hydrogen may take place. Although most of the public attention on hydrogen has been focused on its potential as an alternative energy source to petroleum and other fossil fuels, a hydrogen economy will encompass much more than a substitution of one energy source by another. Widespread use of hydrogen as an energy carrier can transform our society in much the same way that personal computing technologies have. This transforming power arises from the unique capability of hydrogen to link renewable energy resources and zero-emission energy conversion technologies. Hydrogen can be produced from locally available renewable resources, such as solar, wind, biomass, and water, and converted to electricity or fuel at or near the point of use with only heat and water vapor as “emissions.” Hydrogen also lies at the confluence of two emerging trends that will shape our energy future during the first quarter of this century: greater reliance on renewable energy sources and the shift from large, centralized power plants to smaller, decentralized facilities located at or near the point of use. This paper describes these emerging trends and the role of hydrogen in linking them in a way that could transform our society.


1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.


2018 ◽  
Vol 15 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Ponnusamy Kannan ◽  
Samuel I.D. Presley ◽  
Pallikondaperumal Shanmugasundaram ◽  
Nagapillai Prakash ◽  
Deivanayagam Easwaramoorthy

Aim and Objective: Itopride is a prokinetic agent used for treating conditions like non-ulcer dyspepsia. Itopride is administered as its hydrochloride salt. Trimethobenzamide is used for treating nausea and vomiting and administered as its hydrochloride salt. The aim is to develop a novel and environmental friendly method for large-scale production of itopride and trimethobenzamide. Materials and Methods: Itopride and trimethobenzamide can be prepared from a common intermediate 4- (dimethylaminoethoxy) benzyl amine. The intermediate is prepared from one pot synthesis using Phyrdroxybenzaldehye and zinc dust and further reaction of the intermediate with substituted methoxy benzoic acid along with boric acid and PEG gives itopride and trimethobenzamide. Results: The intermediate 4-(dimethylaminoethoxy) benzylamine is prepared by treating p-hydroxybenzaldehyde and 2-dimethylaminoethyl chloride. The aldehyde formed is treated with hydroxylamine hydrochloride. The intermediate is confirmed by NMR and the purity is analysed by HPLC. Conclusion: Both itopride and trimethobenzamide were successfully synthesized by this method. The developed method is environmental friendly, economical for large-scale production with good yield and purity.


Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 241
Author(s):  
Shaden A. M. Khalifa ◽  
Eslam S. Shedid ◽  
Essa M. Saied ◽  
Amir Reza Jassbi ◽  
Fatemeh H. Jamebozorgi ◽  
...  

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.


Sign in / Sign up

Export Citation Format

Share Document