Search results for "WASTE"
showing 10 items of 2580 documents
Energy saving with MSF-RO series desalination plants
2003
Two major techniques are commercially used in different parts of the world: distillation and membrane processes. The dominant distillation process is multi-stage flash (MSF), and the main membrane process is reverse osmosis (RO). Although cost factors vary by site, the total cost of producing potable water from seawater with the RO process is today usually less than thermal desalting processes and the economic advantages of RO vs. evaporation process, such as MSF, are responsible for the rapid increase in use of seawater RO. In many countries both RO and MSF processes are operating. Reduction in product water cost could be achieved when a hybrid MSF-RO system is used, instead of a parallel …
Cost modelling for wastewater treatment processes
2011
Abstract The aim of this paper is to provide a methodology for a better understanding of the cost structure of wastewater treatment processes. This methodology may be useful in the planning of new facilities. The existing models in the literature are focused on the influence of the capacity of plant, expressed as inhabitants or flow rate, on the cost of treatment. We propose a new approach for the operating cost function that includes the most representative variables in the process. The idea is that the modelling of treatment costs enables us to understand the key role of the economies of scale in this context; and also the influence of other variables such as contaminants removed, or the …
Octane Rating of Natural Gas-Gasoline Mixtures on CFR Engine
2014
In the last years new and stricter pollutant emission regulations together with raised cost of conventional fuels resulted in an increased use of gaseous fuels, such as Natural Gas (NG) or Liquefied Petroleum Gas (LPG), for passenger vehicles. Bi-fuel engines represent a transition phase product, allowing to run either with gasoline or with gas, and for this reason are equipped with two separate injection systems. When operating at high loads with gasoline, however, these engines require rich mixtures and retarded combustions in order to prevent from dangerous knocking phenomena: this causes high hydrocarbon (HC) and carbon monoxide (CO) emissions together with high fuel consumption. With t…
Recycled Tyre Rubber Modified Bitumens for road asphalt mixtures: A literature review
2013
AbstractNowadays, only a small percentage of waste tyres are being land-filled. The Recycled Tyre Rubber is being used in new tyres, in tyre-derived fuel, in civil engineering applications and products, in moulded rubber products, in agricultural uses, recreational and sports applications and in rubber modified asphalt applications. The benefits of using rubber modified asphalts are being more widely experienced and recognized, and the incorporation of tyres into asphalt is likely to increase. The technology with much different evidence of success demonstrated by roads built in the last 40years is the rubberised asphalt mixture obtained through the so-called “wet process” which involves the…
Advanced refrigerating plants based on transcritical cycles working with carbon dioxide for commercial refrigeration
2012
Supermarkets and hypermarkets require a huge amount of energy to maintain chilled and frozen food in product display cases and cold storage rooms and thermal comfort in the whole building. Systems exploited require very large refrigerant charges for operation and suffer significant leakages. The challenge for advanced systems, based on equipment which reduce TEWI, suggests the proposal of carbon dioxide: a natural working fluid. This paper deals with a feasibility study of a refrigerating system for a big hypermarket in Sicily based on a three-stage transcritical cycle working with carbon dioxide which is compared with an alternative system composed of two cycles operating as a binary refri…
Modeling and simulation of dense cloud dispersion in urban areas by means of computational fluid dynamics
2011
Abstract The formation of toxic heavy clouds as a result of sudden accidental releases from mobile containers, such as road tankers or railway tank cars, may occur inside urban areas so the problem arises of their consequences evaluation. Due to the semi-confined nature of the dispersion site simplified models may often be inappropriate. As an alternative, computational fluid dynamics (CFD) has the potential to provide realistic simulations even for geometrically complex scenarios since the heavy gas dispersion process is described by basic conservation equations with a reduced number of approximations. In the present work a commercial general purpose CFD code (CFX 4.4 by Ansys®) is employe…
OPTIMIZATION OF GREEN-BUILDING DESIGN PROCESSES - CASE STUDY
2016
The development of a green-building project following a specific reference standard such as LEED, brings new conditions and restrains for all subjects involved in the process. Such changes affect technicians, owners, bureaucracy and also the management tasks either during design or construction phases. Within this scope, project management plays a key role for the optimization of the design-project development. This research analyzes the design process of a single case-study project from the project management perspective, taking into consideration all the activities that negatively affected the project design development. The project selected for the scope of the research is a new school …
The Bioshale Project: Search for a Sustainable Way of Exploiting Black Shale Ores Using Biotechnology
2007
The Bioshale project, involving 13 partners throughout Europe, is co-funded by the European Commission under the FP6 program. The main objective of this project (which started in October 2004) is to identify and develop innovative biotechnological processes for ‘’eco-efficient’’ exploitation of metal-rich, black shale ores. Three extensive deposits have been selected for R&D actions. These are: (i) a site (in Talvivaara, Finland) that, at the outset of the project, had not been exploited; (ii) a deposit (in Lubin, Poland) that is currently being actively mined, and (iii) a third site (in Mansfeld, Germany) where the ore had been actively mined in the past, but which is no longer exploit…
Application of Pulsed Electric Field Treatment for Food Waste Recovery Operations
2016
International audience; Food industry is generating annually huge quantities of by-products and waste, which are generally considered as problem, as their disposal is associated with environmental and health related issues. During the last decade, numerous research groups and industries have been interested in valorizing these by-products by extracting valuable compounds and incorporating them generally in food and/or cosmetic products, which enhances the profitability of the process. Conventional extraction methods (i.e., maceration, thermal extraction) are exten- sively used for such purposes and showed high yields in many cases. However, the need to replace toxic organic solvents, shorte…
A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors
2017
The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability ev…