ABSTRACT
This study uses three data envelopment analysis models to determine the production efficiency of biohydrogen which is produced from macroalgae and other sources by dark fermentation. The efficiency of macroalgae is greatest in batch mode for S. Japonica using a sDFMEC process at pH 5.3, 35 degrees C, 1 g COD/L and a hydrogen production rate (HPR) of 0.34 L/L/h. The highest efficiency is using an internal circulation batch reactor in continuous mode for beverage waste water. The HPR and substrate concentration are the most important factor of biohydrogen efficiency, and efficiency and temperature are the most important factors of HPR. Malaysia and India are the two economies that most benefit from increased production efficiency due to the use of macroalgae. Increasing biohydrogen yield efficiency will improve macroeconomic growth and establish a renewable hydrogen and biohydrogen industry, which is especially efficient related to the economic recovery during the COVID-19 pandemic. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
ABSTRACT
This is an exclusively prepared special issue containing selected papers from well-established events, namely, International Conference on Emerging Nuclear Energy Systems (ICENES) and some invited papers to enrich and broaden the novelty of nuclear energy technologies and its applications. The 19th International Conference on Emerging Nuclear Energy Systems (ICENES 2019) is one of the international conference on scientific, engineering, education and other technical aspects of innovative nuclear reactor design, advanced nuclear technology, energy related technology and its applications.The conference was held in Holiday Inn, Bali, Indonesia (6-9 October 2019), organized by the Bandung Institute of Technology (ITB) and in cooperation with the International Atomic Energy Agency (IAEA). The participants come from several 14 countries and from many institutions from universities, governments, companies, society and some other organizations that shared their ideas and research results on emerging nuclear energy technologies and applications, which covered by keynote speakers, invited and contributed oral talks and poster presentations. Some selected presented paper in the conference have been elected as selected papers after reviewing process to be submitted to the Institute of Physics (IoP), Journal of Physics: Conference Series.Nuclear energy recently is recognized as secure, sustain and green energy source as an ultimate energy resource to secure the future of the mankind and its civilization. Hence, considerable research activities and international collaboration are continuing on innovative nuclear energy systems, reactor physics, radiations and its application, nuclear computational system, including fusion energy technology, fusion-fission hybrids systems, GEN-IV reactors technology, small and modular reactor (MSR) technology, space nuclear reactors, and power systems and accelerator-driven systems technologies. Some related topics are also covered related to nuclear power production;nuclear hydrogen production;hydrogen energy, energy efficiency, and management;solar energy;wind energy;hydrogen production and storage;renewable energy;fuel cells;bio-energy, etc.Finally, on behalf of the organizer and advisory board, we would like to express my sincere appreciation and gratitude to all of authors during the conference and publication processes for their valuable contributions and to the members of the committee, reviewers, and advisors for their excellent works in preparing and finalizing this document. We apologize for any inconveniences for this long process of publication due to our conditions and some restrictions as well as some difficulties during COVID19 pandemicList of Organizer, Editorial Board are available in this Pdf.
ABSTRACT
Carbon dioxide capture and utilization (CCU) technology is a significant means by which China can achieve its ambitious carbon neutrality goal. It is necessary to explore the behavioral strategies of relevant companies in adopting CCU technology. In this paper, an evolutionary game model is established in order to analyze the interaction process and evolution direction of local governments and coal-fired power plants. We develop a replicator dynamic system and analyze the stability of the system under different conditions. Based on numerical simulation, we analyze the impact of key parameters on the strategies of stakeholders. The simulation results show that the unit prices of hydrogen and carbon dioxide derivatives have the most significant impact: when the unit price of hydrogen decreases to 15.9 RMB/kg or the unit price of carbon dioxide derivatives increases to 3.4 RMB/kg, the evolutionary stabilization strategy of the system changes and power plants shift to adopt CCU technology. The results of this paper suggest that local governments should provide relevant support policies and incentives for CCU technology deployment, as well as focusing on the synergistic development of CCU technology and renewable energy hydrogen production technology.
ABSTRACT
An increase in human activities and population growth have significantly increased the world's energy demands. The major source of energy for the world today is from fossil fuels, which are polluting and degrading the environment due to the emission of greenhouse gases. Hydrogen is an identified efficient energy carrier and can be obtained through renewable and non-renewable sources. An overview of renewable sources of hydrogen production which focuses on water splitting (electrolysis, thermolysis, and photolysis) and biomass (biological and thermochemical) mechanisms is presented in this study. The limitations associated with these mechanisms are discussed. The study also looks at some critical factors that hinders the scaling up of the hydrogen economy globally. Key among these factors are issues relating to the absence of a value chain for clean hydrogen, storage and transportation of hydrogen, high cost of production, lack of international standards, and risks in investment. The study ends with some future research recommendations for researchers to help enhance the technical efficiencies of some production mechanisms, and policy direction to governments to reduce investment risks in the sector to scale the hydrogen economy up.
ABSTRACT
Usage of plastics in the form of personal protective equipment, medical devices, and common packages has increased alarmingly during these pandemic times. Though they have served as an excellent protection source in minimizing the coronavirus disease (COVID-19) spreading, they have still emerged as major environmental pollutants nowadays. These non-degradable COVID-19 plastic wastes (CPW) were treated through incineration and landfilling process, which may lead to either the release of harmful gases or contaminating the surrounding environment. Further, they can cause numerous health hazards to the human and animal populations. These plastic wastes can be efficiently managed through thermochemical processes like pyrolysis or gasification, which assist in degrading the plastic waste and also effectively convert them into useful energy-yielding products. The pyrolysis process promotes the formation of liquid fuels and chemicals, whereas gasification leads to syngas and hydrogen fuel production. These energy-yielding products can help to compensate for the fossil fuels depletion in the near future. There are many insights explained in terms of the types of reactors and influential factors that can be adopted for the pyrolysis and gasification process, to produce high efficient energy products from the wastes. In addition, advanced technologies including co-gasification and two-stage gasification were also reviewed.
ABSTRACT
In terms of infection control in hospitals, especially the Covid-19 pandemic that we are living in, it has revealed the necessity of proper disposal of medical waste. The increasing amount of medical waste with the pandemic is straining the capacity of incineration facilities or storage areas. Converting this waste to energy with gasification technologies instead of incineration is also important for sustainability. This study investigates the gasification characteristics of the medical waste in a novel updraft plasma gasifier with numerical simulations in the presence of the plasma reactions. Three different medical waste samples, chosen according to the carbon content and five different equivalence ratios (ER) ranging from 0.1 to 0.5 are considered in the simulations to compare the effects of different chemical compositions and waste feeding rates on hydrogen (H2) content and syngas production. The outlet properties of a 10 kW microwave air plasma generator are used to define the plasma inlet in the numerical model and the air flow rate is held constant for all cases. Results showed that the maximum H2 production can be obtained with ER = 0.1 for all waste samples.