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 ...

/pdf/a-technical-economic-and-environmental-assessment-of-amine-x9xfbbw38g.pdf

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

The Ammonia-Water Mixture Rankine Cycle: Considerations on its Applicability as Bottoming Cycle

Feasibility analysis of a biogas-fuelled trigeneration plant operating with a mGT

Impact of wind speed distribution and management strategy on hydrogen production from wind energy

Chicken manure used as a natural fertilizer, given its high Nitrogen content, requires key actions in odor control that are often difficult to carry out resulting in an image loss for the company. Manure land-filling however is costly as well as incineration and this latter does still require odor control. Energy conversion from chicken manure may turn the cost into an earning that could payback both the investment and the image loss for odorous emissions. In this optic the paper analyses the different technologies that are available for energy conversion from chicken manure namely incineration, gasification, pyrolysis and anaerobic digestion with application to a real case. A large scale egg selling company in central Italy, with three production sites, was selected and its mass and energy flow balance assessed with particular reference to manure production and electricity consumption and expense. Five different technologies were then considered for energy conversion from chicken manure both for a single production site (microscale) and for the three (small scale). Grate incineration with steam production from exhaust gases was considered and discarded because of the too small scale. BTG gasification technology and IPRP pyrolysis technology presented by the authors, were evaluated and the techno-economic assessment showed interesting pay back time with medium to high investment costs and medium efficiencies. Pyrolysis technology with gas-steam combined cycle was considered but the economics show a very high pay back for the investment due to the small scale. Finally anaerobic digestion was evaluated showing the lowest investment cost and efficiency but an interesting payback period also considering that no public financing was considered. This latter solution has been presented to the company that will decide whether to finance the project.© 2004 ASME

Evaluation of Available Technologies for Chicken Manure Energy Conversion and Techno-Economic Assessment of a Case Study in Italy

Significant are the potentials of solid oxide fuel cells (SOFCs) for high efficiency energy generation, also through renewable sources exploitation (syngas and biogas). For these reasons, they can represent a promising technology in the transition to a low carbon economy. Nevertheless, critical technological issues affecting their durability and reliability, beyond the high cost, still impede their widespread. To deeply analyze the potentials relative to high efficiency generation, different architectures for system integration of SOFC and their performance are analyzed, whereas a deep analysis is provided relative to degradation mechanisms limiting the durability of cells.


Keywords:

solid oxide fuel cell;
voltage–current density curve;
SOFC degradation mechanisms;
SOFC integration

Umberto Desideri

Papers

The Ammonia-Water Mixture Rankine Cycle: Considerations on its Applicability as Bottoming Cycle

Feasibility analysis of a biogas-fuelled trigeneration plant operating with a mGT

Impact of wind speed distribution and management strategy on hydrogen production from wind energy

Evaluation of Available Technologies for Chicken Manure Energy Conversion and Techno-Economic Assessment of a Case Study in Italy

Solid Oxide Fuel Cell (SOFC)