International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this paper, a comprehensive analysis of the process of natural gas reform in MIDREX technology was carried out, which was aimed at optimizing this process in order to increase hydrogen yield, reduce the specific consumption of natural gas and minimize the risks of soot formation. The paper also calculates the thermal balance, combined steam-carbon dioxide reforming (SMR + DRM). Based on the conducted studies, optimal reforming modes were determined: gas outlet temperature ~915-920°C; H2O/C ~1.8; increased CO2 fraction. Switching to an optimized reforming mode reduces natural gas consumption by 5.5%, increases H2 output by 6.4%, and reduces CO2 emissions due to better energy efficiency and H2 addition potential. The results obtained in this work are useful for upgrading existing Midrex installations in the direction of decarbonization, including the transition to MIDREX Flex/H2 technologies.

Growing energy and environmental challenges highlight the need for a transition to sustainable supply chains. This paper presents a methodology for assessing a hydrogen supply chain based on steam reforming of biogas (SMR), as a low-carbon alternative to conventional natural gas. The framework covers the entire life cycle, from feedstock to end use. The proposed framework supports strategic planning and provides a basis for future modeling, optimization, and assessment of environmental and socio-economic benefits.

This study proposes a mathematical model for design and optimization of a hydrogen supply chain, covering all stages of the life cycle – feedstocks, production, storage, distribution, end-use in the transport sector. The developed methodology integrates different hydrogen production technologies and takes into account environmental, economic and social impacts in order to identify the most efficient and sustainable configuration. The focus in this work falls on hydrogen production by steam reforming of methane and hydrogen production by electrolysis of water in hydrogen refueling stations. The mathematical model is formulated in terms of MILP programming and can be solved using the GAMS software product. The aim is to find an optimal balance between economic efficiency, environmental sustainability and social impact by using weighted coefficients (weights). The proposed concept provides a decision-making tool for planning hydrogen infrastructure in line with European decarbonization and sustainable transport goals.

The protective coating on a cubic-shaped titanium sample was deposited by the plasma method in an argon atmosphere in several stages, in order to form a continuous barrier on all surfaces of the sample. It was shown that, when the protective coating was deposited by the specified method, partial or complete melting of the powders occurred, and subsequently, when they were deposited on the surface of the substrate, active interaction occurred. This made it possible to form a sufficiently continuous layer on the surface of titanium due to mutual diffusion. It is found out that the deposited protective coating allows titanium to be heated up to 400 ± 10 °C in a hydrogen atmosphere (hydrogen pressure 0.6 ± 0.2 MPa) without interaction with the gas.

We achieved a CT(ozone concentration(ppm) X exposure time(min) )value of 60, which can inactivate coronavirus from 1/10 to 1/100 by operating for 24 h at an appropriate ozone concentration (less than 0.1 ppm) using feedback control in the previous report. In this system, the only way to reduce the ozone concentration is the decomposition reaction of ozone in the natural world, and it was not possible to cope with the rapid increase in ozone. In this study, we investigated the reduction of ozone concentration using hydrogen. As a result, it was clarified that the concentration of ozone rapidly decreased even with about 1/100 of hydrogen’s explosion limit (about 4%).

Low operating temperature, compactness, high efficiency as well as low to zero emissions are features that cause large interest in Proton Exchange Membrane (PEM) fuel cells and are reasons that application of this technology is considered in many areas. However, for a massive deployment of the PEM fuel cell technology to the market, good control and monitoring are mandatory to increase efficiency and durability. For the control and monitoring of PEM fuel cell systems, appropriate system models are required. In this study, a review of modeling approaches to the PEM fuel cell systems is considered

The fossil fuels and the natural gas reserves that have undertaken the role of the locomotive of the industrial period are limited. It is also the biggest factor in environmental problems. All these reasons lead to the need for alternative fuels or resources. Hydrogen is the candidate to be one of these alternatives; is an unlimited clean and efficient fuel. Hydrogen may assume the role of carrier in the process of storage of other alternative energy sources. Today, interest in hydrogen energy is increasing. One of the reasons for this is that hydrogen can be produced from renewable energy sources such as water, biomass, wind and sun as well as hydrogen from primary energy sources. There is no polluting gas emissions when hydrogen is used as fuel. The HHO dry cell is a device that converts water into HHO (oxyhydrogen) gas. In this study, performance of HHO dry cell with 12×12 plate combination was experimentally investigated and modeled with a Rule-Based Mamdani-Type Fuzzy (RBMTF) modeling technique. Input parameters are; plate number, time, current; output parameter is mass flow rate. The coefficient of multiple determination (R2=98.5) for the mass flow rate. RBMTF results indicated that RBMTF can be successfully used in HHO dry cell with 12×12 plate combination.

Building up a low-carbon society has become one of the world’s common challenges. ‘Power to Gas’ efforts – to convert electric power derived from renewable energy into hydrogen – are being actively conducted, mainly in Germany. Similar efforts are

being made in Japan. For example, concerned Japanese cabinet members agreed on a ‘ Hydrogen basic strategy ‘ on Dec. 26 2017. This strategy, with a view to 2050, shows direction and vision toward the realization of a hydrogen society and compiles an action plan to achieve that goal. It aims to scale up hydrogen consumption volume from 0.4 ten thousand t (2020) to 30 ten thousand t (2030) and deduct the unit price of hydrogen from ￥100Nm³ (now) to ￥30Nm³ (2030).We will also try to construct a preliminary autonomous energy system using regenerative energy. In this paper, the operation and function of such a system is described.

This paper presents new methods of thermal processing of the aluminum alloys. It analyses the effects of boiling treatment of alloys Al–Cu and Al–Si in an oxidizing atmosphere on their microstructure, hydrogen content and the coefficient of linear thermal expansion (CLE). An increase of boiling time from 15 to 75 hours results in an initial increase in the hydrogen content in alloys later followed by a decline in the hydrogen content. These changes in the hydrogen content correlate with the dynamics of alloys’ microstructure and their CLE. This study shows that atmosphere with a high oxygen content induces an acceleration of diffusion processes in aluminum alloys. If boiling time does not exceed 30 hours, the hydrogen content in a solid solution and etchability of grain boundaries of α-solid solution decrease and intermediate phases get partially dissolved. We demonstrate that boiling treatment of aluminum alloys in an oxidizing atmosphere leads to a decline of the CLE measured under the temperature 50-450°С which is especially strong when measured under the temperature 250-350°С.