The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

Framework Convention on Climate Change

Capture and sequestration of CO2 from fossil fuel power plants is gaining widespread interest as a potential method of controlling greenhouse gas emissions. Performance and cost models of an amine (MEA)-based CO2 absorption system for postcombustion flue gas applications have been developed and integrated with an existing power plant modeling framework that includes multipollutant control technologies for other regulated emissions. The integrated model has been applied to study the feasibility and cost of carbon capture and sequestration at both new and existing coal-burning power plants. The cost of carbon avoidance was shown to depend strongly on assumptions about the reference plant design, details of the CO2 capture system design, interactions with other pollution control systems, and method of CO2 storage. The CO2 avoidance cost for retrofit systems was found to be generally higher than for new plants, mainly because of the higher energy penalty resulting from less efficient heat integration as well ...

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A technical, economic, and environmental assessment of amine-based CO2 capture technology for power plant greenhouse gas control

Solar Engineering Of Thermal Processes

Global environmental concerns and the escalating demand for energy, coupled with steady progress in renewable energy technologies, are opening up new opportunities for utilization of renewable energy resources. Solar energy is the most abundant, inexhaustible and clean of all the renewable energy resources till date. The power from sun intercepted by the earth is about 1.8 × 1011 MW, which is many times larger than the present rate of all the energy consumption. Photovoltaic technology is one of the finest ways to harness the solar power. This paper reviews the photovoltaic technology, its power generating capability, the different existing light absorbing materials used, its environmental aspect coupled with a variety of its applications. The different existing performance and reliability evaluation models, sizing and control, grid connection and distribution have also been discussed. © 2011 Published by Elsevier Ltd.

A review of solar photovoltaic technologies

Accelerated test for MCFC button cells: First findings

Development and application of an energy and environmental certification method for residential buildings

A micro scale electrically heated rotary kiln for slow pyrolysis of biomass and waste was designed and built at the University of Perugia. The reactor is connected to a scrubbing section, for tar removal, and to a monitored combustion chamber to evaluate the LHV of the syngas. The system allows the evaluation of gas, tar and char yields for different pyrolysis temperature and residence time. The feeding screw conveyor and the kiln are rigidly connected; therefore a modification of the flow rate implies a modification of the inside solid motion and of residence time. The paper provides the theoretical and experimental calculation of the relationships between Residence Time and Flow Rate used to determine the working envelope of the reactor as a function of the feedstock bulk density and moisture content, given the actual heat rate of the electric heaters. The methodology is extendable to any rotary kiln reactor with a rigidly connected feeding screw conveyor, given its geometric and energetic specifications. Part 2 of the paper will extend the energy balance introducing also the yields of pyrolysis products.Copyright © 2006 by ASME

Rotary Kiln Slow Pyrolysis for Syngas and Char Production From Biomass and Waste: Part 1 — Working Envelope of the Reactor

Crude vegetable oil energy conversion is addressed as an important issue for the electric energy production without changing the CO2 concentration in atmosphere. The oil is obtained by grinding oily fruits while a high amount of energy rich residues is produced. The present paper evaluates the thermodynamic and environmental performances of a plant that converts the whole fruit into energy through pyrolysis. Vegetable Oil is used to fuel an internal combustion engine while solid residuals of the oil production are used to fuel an Integrated Pyrolysis Regenerated Plant (IPRP) technology based plant. Tars from pyrolysis process are water scrubbed from syngas and then emulsioned with vegetable oil to increase the electric energy production. IPRP concept is based on a gas turbine (GT) fuelled with the syngas produced in a rotary kiln pyrolyzer fed with Biomass or Wastes (BW GT exhaust gases together with combustion of pyrolysis by-products (char), is used to sustain the pyrolysis process. The IPRP concept was modelled through thermodynamic relations, energy balances and data available in the Literature for oil yields and husks pyrolysis products. The analysis was carried out investigating the influence on plant performances of main thermodynamic parameters of the GT and on pyrolysis temperature. Results are collected for typical parameters of different GT sizes, namely the manometric compression ratio and the turbine inlet temperature. The paper discusses best efficiency points of different plant sizes when fuelled with syngas and tar and oil for three important oil fruits namely sunflower, palm and soybean.Copyright © 2010 by ASME

Assessment of the Energy Conversion of Whole Oil Fruits With a Pyrolysis and Gas Turbine Process

Considering the necessity of producing freshwater from seawater, especially in regions with high solar energy potential, this study proposes a novel system for tri-generation application using solar power through which high capability of freshwater production is available together with electricity and cooling. This system comprises a heliostat field and a phase change material storage unit for continuous production, a gas turbine cycle, a Kalina cycle, an absorption chiller, a humidification dehumidification desalination, and reverse osmosis desalination. The prediction of the behavior of the system has been accomplished utilizing a comprehensive parametric study; afterward, the method of grey wolf optimization has been utilized to optimize the simulation in different multi-objective cases. Regarding obtained results, the net power generation is obtained of about 4137 kW and 41.28 kg/s freshwater with 30.63 % exergetic efficiency and 57.55 $/GJ unit product cost. Also, applying the optimization declines the freshwater production rate, but it improves the other performance indexes. Under optimized condition an exergy efficiency of 32.90 % and a unit product cost of 48.98 $/GJ is achieved. • Parametric study and multi-objective grey wolf optimization of a new solar system • Trigeneration of power, cooling, and freshwater based on a heliostat field • Continuous production thanks to a phase change martial storage unit • Energy, exergy, economic, exergoenvironmental, and sustainability analyses • The optimum exergy efficiency and unit products' cost are 32.9 % and 48.98 $/GJ. 

Multi-objective grey wolf optimization and parametric study of a continuous solar-based tri-generation system using a phase change material storage unit

Umberto Desideri

Papers

Accelerated test for MCFC button cells: First findings

Development and application of an energy and environmental certification method for residential buildings

Rotary Kiln Slow Pyrolysis for Syngas and Char Production From Biomass and Waste: Part 1 — Working Envelope of the Reactor

Assessment of the Energy Conversion of Whole Oil Fruits With a Pyrolysis and Gas Turbine Process

Multi-objective grey wolf optimization and parametric study of a continuous solar-based tri-generation system using a phase change material storage unit