6 research outputs found
Recycling of Tire Waste Using Pyrolysis: An Environmental Perspective
End-of-life tires are a common and hazardous type of waste. According to estimates, over 2 billion tires are produced each year, and all of these tires will eventually be discarded as waste. Landfilling waste tires is strictly prohibited by the regulations of the European Union and the Environmental Protection Agency; they should be retreated and reused in an alternative scenario. As a waste-to-energy technology, pyrolysis, can emerge as a useful technique to thermally degrade waste tires and produce useful byproducts in the form of liquid, gas, and char. The derived products can be filtered and used in further industries as biofuel substances. Pyrolytic oil has a high calorific value of 35â45 MJ/kg and can be used as an alternative to diesel to fuel specific vehicles. However, the environmental footprint of the technology has been widely neglected when using waste tires as feedstock. Made from synthetic and natural rubbers, tires contain a high amount of sulfur and styrene, which can cause toxic emissions and negatively affect the environmental sustainability of pyrolysis. This concept paper aims to elaborate the parameters of an operating rotary kiln reactor by reviewing previous life cycle assessment studies and applying the methodology to an industrial-scale pyrolysis plant in Northern Cyprus. Results found a maximum production yield of 45.6% oil at an optimal temperature of 500 °C. Influential parameters such as temperature, residence time, and heating rate are reviewed based on their overall contribution to the production yield and the environment. The outcome of this paper emphasizes the need in the literature to apply environmental analyses to industrial and commercial-scale reactors to test the sustainability of using pyrolysis as a tire waste management strategy. In addition, complex engineering concepts and tasks in waste recycling will be discussed in a broad and accessible manner, with the implications and future work discussed
Alignment of project management with business strategy in construction: evidence from the Turkish contractors
The importance of fit between an organization's implementation of project management (PM), and its business level strategy is emphasized in the literature. However, there are a limited number of studies investigating the relationship between business level strategy and implementation of PM in the construction industry. This paper aligns one of the business strategies, namely differentiation, with the PM process. A framework representing differentiation in the construction industry is proposed in this study. Structural equation modelling (SEM) is used to validate the relationship between differentiation and the PM process. The results show that a relationship between differentiation strategy and PM exists. The two types of differentiation are revealed, namely âproduct variety and speed-related differentiationâ (PSD) and âquality and image-related differentiationâ (QID). The companies trying to differentiate based on PSD should focus on cost, time and quality management. Change management and project planning are identified as important drivers of differentiation based on PSD. On the other hand, the companies trying to differentiate on QID should consider health, safety and environmental issues as well as quality. Companies should also manage their resources effectively to support the PM process that in turn leads to successful differentiation. Companies can utilize the research findings as a guideline while formulating their differentiation strategies
Combining point correlation maps with self-organising maps to compare observed and simulated atmospheric teleconnection patterns
We use a new method based on point correlation maps and self-organising maps (SOMs) to identify teleconnection patterns in 60 yr of National Centres for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR) sea level pressure (SLP) re-analysis data. The most prevalent patterns are the El Nino Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and the Southern Annular Mode (SAM). Asymmetries are found between base points in opposite centres of action of the NAO and the Pacific North America pattern (PNA). The SOM-based method is a powerful tool that allows us to efficiently assess how realistically teleconnections are reproduced in any climate model. The degree of agreement between modelled and re-analysis-based teleconnections (or between different models) can be summarised in a single plot. Here, we illustrate this by assessing the skill of the medium complexity climate model FORTE (Fast Ocean Rapid Troposphere Experiment). FORTE reproduces some realistic teleconnections, such as the Arctic Oscillation (AO), the NAO, the PNA, the SAM, the African Monsoon and ENSO, along with several other teleconnections, which resemble to varying degrees the corresponding NCEP patterns. However, FORTE tends to underestimate the strength of the correlation patterns and the patterns tend to be slightly too zonal. The accuracy of frequency of occurrence is variable between patterns. The Indian Ocean is a region where FORTE performs poorly, as it does not reproduce the teleconnection patterns linked to the Indian Monsoon. In contrast, the North and equatorial Pacific and North Atlantic are reasonably well reproduced