Cement, Energy and Environment

.. HEAT-CONDUCTING POLYTHENE TO TAKE PLACE OF WIRES? New York: American scientists have developed a new variety of polythene, the most widely used polymer, that can conduct heat like most metals yet remains an electrical insulator. The new form of polythene can be used as a cheap alternative to metals in electric applications like a computer processor chip where it is important to draw heat away from an object. Polymers are materials made of long, chain– like molecules. Researchers at Massachusetts Institute of Technology in US found that by getting all polythene molecules line up the same way, rather than forming a chaotic tangled mass, as they normally do, the polymer can be changed into heat conductor. The team achieved that by slowly drawing a polythene fibre out of a solution, using an atomic force microscope. The fibre was about 300 times more thermally conductive than normal polythene along the direction of the individual fibres, said team leader, Gang Chen of MIT. FUTURISTIC TECHNOLOGY The high thermal conductivity of the new fibre makes it useful for dissipating heat in many applications such as solar hot water collectors, heat exchangers and electronics, said the report published in journal Nature Materials. Chen said that earlier attempts to create a heat– conducting polymer by adding other materials had yielded modest result as the interfaces between the two kinds of material tend to add thermal resistance by scattering heat. If such fibers could be made in large quantities, they could provide a cheaper alternative to metals used for heat transfer in many applications, especially ones here the directional characteristics would come in handy, such as heat exchanger fins and cellphone casings. Other applications might be devised that take advantage of the material's unusual combination of thermal conductivity with light weight, chemical stability and electrical insulation. Courtesy: The Times of India, March 10, 2010. Re'urr- •·g ~ ...... .. Gas1fiCat1on Air seperal!on COAL TO LIQUID Did you know that coal when liquefied can yield upto 68 per cent diesel and 30 per cent naphtha What is coal to liquid Converting coal to a liquid fuel (CTL} is a process in which coal liquefaction is done through a series of processes. Once liquefied, this fuel can be utilized as an alternative to oil. There are two different methods for converting coal into liquid fuels– direct liquefaction and indirect liquefaction. Direct liquefaction works by dissolving coal in a solvent at high temperature and pressure. This process is highly efficient, but the liquid products require further refining to achieve high grade fuel quality. Indirect liquefaction gasifies the coal to form a synthetic gas or syngas (a mixture of hydrogen and carbon monoxide). This gas is then condensed over a catalyst - the Fisher-Tropsch process - to produce high quality, ultra– clean products. An array of products can be made using these processes - ultra-clean petrol and diesel, as well as synthetic waxes, • '"'C.·f+YID.a ""lf' ll.l'l'lo6f • • ·~ ~ICCII~-.<"111CfiCI"'