179 research outputs found
The impact of transformational leadership on job satisfaction and organizational citizenship behavior: the mediating role of affective trust and emotional intelligence
Διπλωματική εργασία--Πανεπιστήμιο Μακεδονίας, Θεσσαλονίκη, 2019.Though Greece has suffered a severe economic crisis, this study is supposed to prove that employees can be satisfied from their jobs when they have motives other than compensation and reward system. The goal of this study is to prove that some leadership traits such as affective trust and emotional intelligence are vital to the employees’ well-being inside a company
Increased charcoal yield & production of lighter oils from the slow pyrolysis of biomass
In an effort to reduce CO2 emissions from solid fuels, a considerable amount of research is going into how improve the manufacturing processes and product properties of the products from pyrolysis. One aspect that is often overlooked is the production of charcoal for cooking and soil remediation, which is an inefficient conversion process. There is considerable interest into using additives to increase charcoal yields, and based on the observation from fast pyrolysis work that certain catalyst tar cracking pathways can deposit considerable amounts of coke on the surface of the catalyst, there is a potential application to slow pyrolysis processes producing charcoal. Alumino-silicate catalysts have been shown to have a relatively high tendency to do this. This work hypothesises that this catalysation can be applied to slow pyrolysis, with low cost alumino-silicate minerals, specially bentonite clay, which has been added to pine pyrolysis in concentrations up to 60% wt (against input biomass) at temperatures 300–700 °C.
This study has shown that the use of bentonite clay minerals can be beneficial to the process, as there is an increase in the charcoal yield from biomass, whilst the proximate analysis of the charcoal shows little change from levels expected from biomass only pyrolysis. The conversion of oil to charcoal was more effective at high temperatures due to higher levels of oil cracking. At 700 °C with 60% clay loading, charcoal yield increased 16%wt (dry ash free basis) was seen, while at the same time 19% extra gas was produced at the expense of 35% of the oil from raw pine pyrolysis. This indicates fuel properties of the charcoal are predictable, and changes in yield considerable. At the same time, the abundance of lower molecular weight oils is increased (relative to 4-methyl phenol). It is though that pyrolysis oil reacts with the clay, causing the heavier tars to disproportionate into charcoal and gas
The impact of transformational leadership on job satisfaction and organizational citizenship behavior: the mediating role of affective trust and emotional intelligence
Διπλωματική εργασία--Πανεπιστήμιο Μακεδονίας, Θεσσαλονίκη, 2019.Though Greece has suffered a severe economic crisis, this study is supposed to prove that employees can be satisfied from their jobs when they have motives other than compensation and reward system. The goal of this study is to prove that some leadership traits such as affective trust and emotional intelligence are vital to the employees’ well-being inside a company
Different reaction behaviours of the light and heavy components of bio-oil during the hydrotreatment in a continuous pack-bed reactor
This study aims to investigate the hydrotreatment of bio-oil in a continuous packed-bed reactor at around 375°C and 70 bar. The bio-oil was produced from the grinding pyrolysis of mallee wood in a grinding pyrolysis pilot plant. Our results indicate that the lighter and heavier components in the same bio-oil could behave very differently. Their behaviour can be affected very significantly by the overall bio-oil liquid hourly space velocity. While the residence time of the light species that evaporate instantly could be very short, the residence time of heavy species passing through the catalyst bed in the form of liquid could be very long. When a commercial pre-sulphided NiMo/Al2O3 catalyst came into contact with the heavy bio-oil species, significant exothermic reactions would take place, which result in the deactivation of hyperactive sites in the catalyst. The NiMo/Al2O3 catalyst used was less active in hydrotreating the heavier bio-oil species than in hydrotreating the lighter bio-oil species. However, even at very low extents of hydrotreatment, the bio-oil structure and properties, e.g. coking propensity, could be drastically improved
Catalytic pyrolysis of rice husk for bio-oil production
Catalytic pyrolysis experiments have been carried out on Brunei rice husk (BRH) to obtain bio-oil using a fixed-bed pyrolysis rig. ZSM-5, Al-MCM-41, Al-MSU-F and Brunei rice husk ash (BRHA) were used as the catalysts for the catalytic pyrolysis experiments and comparison was done to analyse the changes in the bio-oil properties and yield. Properties of the liquid catalytic and non-catalytic bio-oil were analysed in terms of water content, pH, acid number, viscosity, density and calorific value. The bio-oil chemical composition shows that ZSM-5 increases the production of aromatic hydrocarbons and light phenols, whilst Al-MCM-41 reduces the acetic acid production. The catalytic runs increased the calorific value and water content in the bio-oil, whilst viscosity, density and acid number is decreased
FCC testing at bench scale: New units, new processes, new feeds
As the FCC process has evolved over decades, several laboratory scale equipment have appeared to maintain
a proper assessment of catalysts activity. Several laboratory equipments are available for simulating
the FCC process, from the well known fixed bed, MicroActivity Test to newer, fluid bed or transported
bed units. As well, a number of units have been created to simulate other parts of the process such as
regenerator or stripper, The increased pressure for treating non-conventional feeds, from reprocessing
gasoline to extra-heavy feeds or oils produced from biomass containing large amounts of heteroatoms,
increase the needs to have a laboratory test which is as close as possible to the process so that data
extraction from the laboratory test are simplified, thus less prone to errors or misunderstanding.Financial support by MICINN (Consolider-Ingenio 2010 MULTICAT) and MINECO (Project MAT2011-29020-0O2-02 and Subprogram for excellence Severo Ochoa, SEV 2012 0267) is gratefully acknowledged.Corma Canós, A.; Sauvanaud, LL. (2013). FCC testing at bench scale: New units, new processes, new feeds. Catalysis Today. 218-219:107-114. doi:10.1016/j.cattod.2013.03.038S107114218-21
Opportunities and challenges in sustainable treatment and resource reuse of sewage sludge: A review
Sludge or waste activated sludge (WAS) generated from wastewater treatment plants may be considered a nuisance. It is a key source for secondary environmental contamination on account of the presence of diverse pollutants (polycyclic aromatic hydrocarbons, dioxins, furans, heavy metals, etc.). Innovative and cost-effective sludge treatment pathways are a prerequisite for the safe and environment-friendly disposal of WAS. This article delivers an assessment of the leading disposal (volume reduction) and energy recovery routes such as anaerobic digestion, incineration, pyrolysis, gasification and enhanced digestion using microbial fuel cell along with their comparative evaluation, to measure their suitability for different sludge compositions and resources availability. Furthermore, the authors shed light on the bio-refinery and resource recovery approaches to extract value added products and nutrients from WAS, and control options for metal elements and micro-pollutants in sewage sludge. Recovery of enzymes, bio-plastics, bio-pesticides, proteins and phosphorus are discussed as a means to visualize sludge as a potential opportunity instead of a nuisance
Conventional and microwave induced pyrolysis of coffee hulls for the production of a hydrogen rich fuel gas
Glycothermal Synthesis and Catalytic Properties of Nanosized Zn1−x Co x Al2O4 (x = 0, 0.5, 1.0) Spinels in Phenol Methylation
PRODUCTION OF TRANSPORTATION FUELS BY UPGRADING OF BIOMASS FLASH PYROLYSIS LIQUIDS VIA FCC TECHNOLOGY
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