Green Chemistry

Green Chemistry
Green chemistry refers to the intentional use of tools developed from chemical interactions to protect the environment and reduce carbon emissions through the development of energy efficient systems. This is seen in Carnot’s theory on entropy, which intones that energy must flow in a particular direction for work to be done. For instance, at the top of a waterfall, the water has high potential energy, but low kinetic energy. As the water drops down the waterfall, its kinetic energy increases even as the potential energy reduces. As a result, potential energy is turned into kinetic energy. The transition from low-kinetic energy and high-potential energy to high-kinetic energy and low-potential energy can be explained using the molecular bombardment theory – entropy. If the water has high-potential energy, the molecular bombardment is low with the reverse equally being true such that low-potential energy matched by high molecular bombardment.
If to take another example, let us consider an ice cube placed in a glass half-full of warm water. The ice will gain heat energy from the warm water and hence melt, while the warm water will lose heat energy to the ice and thus become cold. In other words, the heat exchange causes the fast moving molecules of the warm water to lose energy and thus the particles vibrate less vigorously. Conversely, the ice molecules gain heat energy and thus become more active with their particles vibrating at a faster rate. As a result, the ice cube melts, to imply that the molecules are able to move freely.

Eventually, the two systems balance in terms of energy content and hence the melted ice is indistinguishable from the cold water. This proves the theory of energy entropy, which asserts that energy exists as disordered molecules. The second law of thermodynamics, which concedes that energy the entropy of a closed system can never be decreased, best explains the concept. In other words, as long as no energy is lost, then the entropy energy of the earth’s system will remain constant or rise. This means that it is possible to develop efficient fuels capable of producing the required energy while minimizing waste and emission.
An example of green chemistry can be seen in the petroleum industry where chemists are leading research on fuel development. Low sulfur and lead fuels present a good illustration of one of the more visible products of green chemistry. Unlike other fuels derived from petroleum, low sulfur and lead fuels are accompanied by a guarantee that their combustion will produce lower amounts of sulfur and lead, with the result that pollution levels are lowered. Another example of green chemistry can be seen the development of biofuels from organic material and presented as either first-, second- or third-generation biofuel. The organic material is subjected to biochemical, chemical, or thermal conversion and the resultant energy may be in gaseous, liquid, or solid state. The first-generation biofuels are extracted from food crops – such as vegetables, sugar cane, and grains. The second-generation biofuels are extracted from plants with high cellulose content including timber, wheat straw, willow, and miscanthus. The third-generation biofuels are extracted from algae that are grown to produce oil with ethanol, butanol, gasoline, and diesel acting as by products. The developments noted in the petroleum industry will not only reduce environmental pollution, but also reduce dependence of non-renewable energy thereby improving energy security. As a result, green chemistry has made significant strides in protecting the environment by reducing pollution.