Energy sources conventional

Item/Technologv Class reaction separation Energy Source conventional... 

Over 80 percent of the world s energy consumption comes from nonrenewable sources that cannot be sustained indefinitely under current practices. If technological advances continue to make conventional energy resources plentiful and affordable for many years to come, the transition to more sustainable energy sources can be smooth and minimally disruptive. 

In Japan Chlorella spp has been produced for food in continuous aseptic systems in conventional bioreactors. The organisms are grown in the dark as heterotrophs using sucrose (in the form of molasses) or glucose as carbon and energy source. Production has been 2,000-3,000 tonnes per year at a selling price of (US)10-22 kg 1 (1990 prices). This product is sold as a high-value health food. 

The preparation of 1,3-dialkylimidazolium halides by conventional heating in solvent under reflux requires several hours to afford reasonable yields and also uses a large excess of alkyl halides and/or organic solvents as the reaction medium. To circumvent these problems Varma and coworkers [106] investigated the preparation of a series of ionic liquids 72 (Scheme 8.74), using microwave irradiation as the energy source, by simple exposure of neat reactants, in open containers, to microwaves by use of an unmodified household MW oven (240 W). 

In a recent study, classical heating, microwave radiation and gamma radiation have been compared as energy sources to perform 1,3-dipolar reactions between unsaturated oximes and conventional dipolarophiles. On using gamma radiation the reactions were clean and yields obtained were similar to those for the thermal reactions. However, microwave radiation reactions were extremely clean, occurred more rapidly and gave higher yields [102],... 

Since the supply of hydrogen in the long term depends on different technical and energy policy developments and frame conditions, such as the expansion of renewable energy sources, the development of clean coal technologies or the required reduction of C02 emissions, hydrogen production is simultaneously closely linked to the conventional energy supply system. 

Both efficiency and environmental impact are important factors to consider when comparing energy sources. In the following ThoughtLab, you will research and compare alternative and conventional energy sources. 

Explain the concept of efficiency, and discuss the efficiency and environmental impact of conventional and alternative energy sources. 

---