Renewable thermal

D. L. Klass, ed., A. Directory of U.S. Renewable Energy Technology Vendors, Biomass, Photovoltaics, Solar Thermal, Wind, Biomass Energy Research Association, Washington, D.C., 1990, for U.S. Agency for International Development, 74 pp. 

The aroma and red color of the spice saffron are partly due to the style-specific accumulation of carotenoid cleavage products produced by both enzymatic and thermal degradation. M. Giaccio reviewed the renewed interest in saffron as a colorant, spice, and nutraceutical. " Crocetin is a C20 apocarotenoid derived from zeaxanthin (Figure 5.3.4B). ... 

Consequently, the net OLR has increased by 0.006 W m-2 since 1880. This means that about one-third of today s thermal pollution (0.02 W m-2) is emitted from Earth. In the long term our use of non-renewable energy will cause a global temperature increase up to a point where the net OLR balances the net heat generation. Meanwhile, nature has some means of delaying global warming. 

At the same time, our major energy supplies (oil, coal, and gas) are finite. They are not renewable, yet we burn through these fuels as if there were no tomorrow. The energy supplies which are renewable (solar, wind, thermal) are not being used as widely or thoughtfully as they should be. 

Paksoy, H.O., et al., 2000. Heating and cooling of a hospital using solar coupled with seasonal thermal energy storage in an aquifer, Renewable Energy, 19, 117-122. 

Wind, solar thermal, and photovoltaic power together accounted in 1998 for only about 1% of U.S. electricity generation from renewable sources and only about 0.1% ofall electricity (DOE/EIA 1999a). 

The first type of model considers the heat transfer surface to be contacted alternately by gas bubbles and packets of closely packed particles. This leads to a surface renewal process whereby heat transfer occurs primarily by transient conduction between the heat transfer surface and the particle packets during their time of residence at the surface. Mickley and Fairbanks (1955) provided the first analysis of this renewal mechanism. Treating the particle packet as a pseudo-homogeneous medium with solid volume fraction, e, and thermal conductivity (kpa), they solved the transient conduction equation to obtain the following expression for the average heat transfer coefficient due to particle packets,... 

This packet renewal model has been widely accepted and in the years since 1955 many researchers have proposed various modifications in attempts to improve the Mickley-Fairbanks representation. Several of these modifications dealt with the details of the thermal transport process between the heat transfer surface and the particle packet. The original Mickley-Fairbanks model treated the packet as a pseudo-homogeneous medium with a constant effective thermal conductivity, suggesting that... 

Bridgwater, A. V., Renewable fuels and chemicals by thermal processing of biomass. Chemical Engineering Journal 2003,19, 87-102. 

---