Performance - Evaluation of Lignite in a downdraft Gasifier
India is a developing country which lacks an adequate supply of electricity. For many of the interior regions of India, gasification is a good way to produce electricity with standalone gasifier. In many regions of India as well as in the world, a large reserve of lignite is available. Lignite could be a fuel for gasification system. This paper presents the result of the experimental investigations carried out using lignite to investigate the effect of fuel size variation on gas generation rate and performance parameter in terms of calorific value of producer gas and gasifier efficiency in downdraft gasifier. Based on the realization, while studying the effect of gas generation rate, the choice of particle size is playing an important role for flowability study and performance of gasifier. The present work investigates the effect of lignite size variation on temperature profile at different zones in gasifier. They were in the range of 16-19 mm, 19-22 mm, 22-25 mm particle sizes of lignite. For comparative studies, experiments were also carried out on uneven size wood and lignite. It was observed from three particle sizes of lignite that better calorific value (629 kcal/m 3 ) and efficiency of gasifier (46.092%)
Hydrogen-rich gas production from biomass air and oxygen/steam gasification in a downdraft gasifier
Biomass gasification is an important method to obtain renewable hydrogen. However, this technology still stagnates in a laboratory scale because of its high-energy consumption. In order to get maximum hydrogen yield and decrease energy consumption, this study applies a self-heated downdraft gasifier as the reactor and uses char as the catalyst to study the characteristics of hydrogen production from biomass gasification. Air and oxygen/steam are utilized as the gasifying agents. The experimental results indicate that compared to biomass air gasification, biomass oxygen/steam gasification improves hydrogen yield depending on the volume of downdraft gasifier, and also nearly doubles the heating value of fuel gas. The maximum lower heating value of fuel gas reaches 11.11MJ/Nm3 for biomass oxygen/steam gasification. Over the ranges of operating conditions examined, the maximum hydrogen yield reaches 45.16gH2/kg biomass. For biomass oxygen/steam gasification, the content of H2 and CO reaches 63.27–72.56%, while the content of H2 and CO gets to 52.19–63.31% for biomass air gasification. The ratio of H2/CO for biomass oxygen/steam gasification reaches 0.70–0.90, which is lower than that of biomass air gasification, 1.06–1.27. The experimental and comparison results prove that biomass oxygen/steam gasification in a downdraft gasifier is an effective, relatively low energy consumption technology for hydrogen-rich gas production.
School Principals and Education Law: What do they know, what do they need to know?
Principals now work in complex and challenging environments where uncertainty and change are the hallmarks of their roles and responsibilities. As such, the knowledge and capability demands on principals have expanded, including those related to education law. While these matters attracted some research interest a number of years ago, there has been little recent work in the area of principals and education law. This article reports on an exploratory study into aspects of the legal knowledge held by Tasmanian government school principals, particularly concerning non-sexual physical contact between teachers and students. The research was undertaken using a small-scale, mixed-methods research design, which required principals to respond to various legal scenarios. Three key findings emerged from the study. First, principals used two different levels of working knowledge about education law  one related to legal problems, and the other to legally-related routine activities. Second, on the particular topic of physical contact, some knowledge held by principals was not legally accurate. Third, for major legal issues, participants indicated that they acquired access to information from legal experts. The situation for routine legal matters was less clear, although in-service training and practical experience were identified as potential sources of knowledge. Participants recognised the importance of a sound knowledge of education law, especially for dealing with security and safety issues and preferred to access further information through in-service training. Notably, the findings of the study are broadly consistent with those from earlier Australian and international research, suggesting that much remains to be done in the area of principals’ education law knowledge.