Search results for "Chemical engineering"

Future district heating plant integrated with municipal solid waste (MSW) gasification for hydrogen production

2019

Abstract Characterizing municipal solid waste (MSW) is a critical step in planning, designing, operating, or upgrading solid waste management systems. For a theoretical investigation of hydrogen production by gasification and water-gas shift reaction, we characterized Norwegian MSW and used the data. Three different gasification setups, named as ‘A-1’, ‘A&S-2’, and ‘S-3’ were modeled using Aspen plus simulation software for direct and indirect gasification processes according to the different gasification agents. The MSW characterization result showed a reasonable agreement with existing studies in different countries. The maximum hydrogen yield achieved in setup ‘S-3’ was around 94% of the…

Electricity demand response schemes in China: Pilot study and future outlook

2021

Abstract Electricity demand response (DR) improves the overall energy management efficiency and allows for the integration of large-scale renewable energy into the power grid through interactive management and control of the supply and demand sides. However, in China and other emerging countries (e.g., Japan and Australia) with DR programs, the DR market mechanism is not well-established. This is particularly the situation in countries where the state power system is not freely open to participate in the DR market. Previous research has proven that considerable DR resources are largely existing in the demand side; however, the dearth of a market mechanism hinders the development of DR. Henc…

A novel pressure regulation system based on Banki hydro turbine for energy recovery under in-range and out-range discharge conditions

2021

Abstract Efficiency improvement of water distribution networks needs to be in place to guarantee a long life period under suitable operating conditions. Excessive pressure is among the well-known issues encountered in water distribution networks which can cause strength damages to the piping system. In order to overcome this drawback and to reach a suitable water pressure delivery, the present work suggests a novel pressure regulation system. This regulation system is consisting of a Banki turbine equipped with a mobile flap as a control device. The suggested pressure regulation system was experimentally and numerically investigated under in-range i.e. like actual water distribution network…

Performance evaluation of hybrid RO/MEE systems powered by a WTE plant

2008

Abstract The solid waste management is, in different contexts, a very critical issue. The use of landfills can no longer be considered a satisfactory environmental solution, therefore new methods have to be chosen and waste-to-energy (WTE) plants would provide an answer. Today's WTE plants are a far cry from their polluting predecessors. Using modern combustion and pollution control technology, WTE plants are able to retrieve considerable amounts of energy from waste combustion while minimizing emissions. As we know, is possible to recover thermal energy by combusting municipal solid waste (MSW) for electricity generation and district heating. However, with everincreasing population and rap…

Evaluation of the Economic and Environmental Performance of Low-Temperature Heat to Power Conversion using a Reverse Electrodialysis – Multi-Effect D…

2019

In the examined heat engine, reverse electrodialysis (RED) is used to generate electricity from the salinity difference between two artificial solutions. The salinity gradient is restored through a multi-effect distillation system (MED) powered by low-temperature waste heat at 100 °C. The current work presents the first comprehensive economic and environmental analysis of this advanced concept, when varying the number of MED effects, the system sizing, the salt of the solutions, and other key parameters. The levelized cost of electricity (LCOE) has been calculated, showing that competitive solutions can be reached only when the system is at least medium to large scale. The lowest LCOE, at a…

Fabrication of cobalt and cobalt oxide/graphene composites: towards high-performance anode materials for lithium ion batteries.

2010

Near-infrared emissive bacteriochlorin-diketopyrrolopyrrole triads: Synthesis and photophysical properties

2019

International audience; The synthesis of unprecedented energy transfer triads containing a near-infrared (NIR) emissive bacteriochlorin subunit and two diketopyrrolopyrrole (DPP) moieties linked to each other via ethynyl or zero-carbon spacers is presented. Their optical and fluorescence properties were determined in CHCl3 and toluene. These photophysical measurements highlight the ability of DPP scaffold to act as an effective energy donor, which once excited in the range 450-550 nm resulting nearly exclusively NIR emission of hydroporphyrin (ETE > 96%). Since DPP dyes are valuable structurally tunable fluorophores that may be used in the construction of high-performance multicomponent pho…

Subtractive versus mass conserving metal shaping technologies: an environmental impact comparison

2015

The scientific studies in the domain of environmental sustainability of metal processing technologies predominantly focus on conventional material removal processes, as milling and turning. Despite some exceptions, many other non-machining technologies, such as metal forming processes, are still not well documented in terms of their energy and resource efficiency. Moreover, to properly evaluate the environmental impact of a given process, a standing-alone approach is no longer sufficient. In order to offer a valuable contribution in the domain of metal shaping sustainability, the present paper proposes a thorough methodology entailing to compare, from the environmental point of view, two tr…

Mixing dynamics in uncovered unbaffled stirred tanks

2014

Abstract The present work is aimed at providing experimental information on mixing rates in an unbaffled vessel under free surface vortexing conditions. The planar laser induced fluorescence (PLIF) technique was used for measuring the dispersion dynamics of a passive tracer over a vertical section of the vessel. In agreement with the quite scant literature information available for these systems, results confirm the existence of two well defined, partially segregated, zones that give rise to a double mixing dynamics behavior. A suitable mixing time definition is proposed and applied to a number of experimental runs with different stirrer geometries and agitation speeds. Results confirm that…

CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: H…

2016

Abstract Integrated power plants in “dual purpose” configuration may represent a viable option for energy cost abatement of desalted water produced by MED-TVC (Multiple Effect Distillation along with Thermal Vapour Compression). In this paper an existing large MED-TVC plant with a 36,000 m 3 /day capacity is studied: a plant retrofit is designed, based on a steam power plant with condensation and steam extraction used to drive the steam ejector. As the plant operates in CHP (Combined Heat and Power) mode, the possibility to assess the integrated “CHP + MED-TVC” as high efficiency cogeneration according to Directive 2004/8/EC is discussed. Based on a model developed in Engineering Equation S…