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This paper presents a survey assessing factors contributing to the public acceptance of hydrogen as a fuel for vehicles in Malaysia. For the survey, a set of questionnaires was prepared in Google Forms and distributed to respondents through social media (WhatsApp, Facebook, Messenger, and Telegram). The survey was conducted during the movement order control in Malaysia due to the global pandemic, and the responses were collected from November to December 2021. One hundred seventy-six local respondents voluntarily participated in the survey. The responses were analysed using non-parametric statistical tests in the Statistical Package for the Social Sciences (SPSS). The highest number of respondents from the 18–25 age group is 101 (57.39 per cent), followed by 26–35 (26.7 per cent) and 36–45 (7.95 per cent). The statistical analysis of the survey shows that socio-demographics is a factor influencing public acceptance. The Spearman correlation test shows a positive correlation between Malaysia's environmental awareness and the potential to use a hydrogen-powered car; hence, there is a good chance of Malaysian acceptance of using hydrogen as fuel. Safety and public perception of hydrogen-powered cars also indicate a positive correlation, where the R- values for all questions are more than 0.5, indicating that safety is a factor that shapes public acceptance. Although the number of samples does not represent the population, it provides a reasonable basis to examine the influencing factors of public acceptance of hydrogen as a fuel for vehicles. [ABSTRACT FROM AUTHOR]

Gas explosions in obstructed vessels have been investigated for many years. However, the flame acceleration mechanism of enriched-hydrogen fuels with diluents in the piping system has received little systematic study in the literature. This particular study aimed to analyse the flame front mechanism of hydrogen-diluents/air explosion inside the pipe by considering the influence of tee junction distance from the ignition points. The tests were performed using H 2 /diluents-air at different concentrations and ignition positions, in two different tee junction pipe configurations. From the results, the worst case of explosion severity was found in 95% H 2 –2.5% Ar–2.5% N 2 /air for all ignition positions. In general, if ignition happened at the tee junction, the overpressure and rate of pressure rise profiles showed almost a similar trend on both configurations. Similar trend was also observed for the flame flow characteristic analysis. Overall, it was clearly demonstrated that a shorter distance between ignition point and obstacles resulted in higher explosion severity. [ABSTRACT FROM AUTHOR]

Hydrogen is a promising fuel for the future. In recent years it has been successfully utilised in industries, particularly in refineries and petrochemicals. In previous studies, the effect of inhibitors on hydrogen explosion behaviour has been investigated in different systems, yet only scarce data are available. Therefore, experimental study is carried out to investigate the effects of argon, nitrogen and carbon dioxide on hydrogen/air explosion in a branched pipe configuration. The fuel/air mixtures were ignited at three different ignition positions, A, B and D. The results show that, when ignited at the furthest distance (position A), the tee junction area is most vulnerable to the critical pressure impact of gas explosion. However, no similar trend was observed at the other ignition positions. In addition, mixtures with the compositions 95% H 2 –2.5% Ar–2.5% N 2 /air, 95% H 2 –5% N 2 /air, H 2 /air and 95% H 2 –5% Ar/air showed higher risks due to the higher diffusivity ratio and the associated rate of pressure rise. This phenomenon is highlighted in the discussion part of this paper. The results show that mixtures with CO 2 lead to lower severity than other compositions (∼50% reduction), as the average recorded maximum flame speed for this particular mixture was lower at all of the ignition points. This suggests that the effectiveness of the inhibitors should be in the order of Ar < N 2 < CO 2 . [ABSTRACT FROM AUTHOR]