Environmental problems technology

Due to possible environmental problems with acetone, new technologies are being developed for the production of deoiled lecithins involving treatment of Hpid mixtures with supercritical gases or supercritical gas mixtures (10—12). In this process highly viscous cmde lecithin is fed into a separation column at several levels. The supercritical extraction solvent flows through the column upward at a pressure of 8 MPa (80 bar) and temperature between 40 and 55°C. The soy oil dissolves together with a small amount of lecithin. 

Since the 1970s, technological advances have solved many environmental problems associated with energy production and consumption, and proven that more energy consumption does not necessarily mean more pollution. The fossil fuel industries are producing and distributing more energy less expensive-... 

Martin, D. J., and Michaelis. (1992). Research and Technology Strategy to Help Overcome the Environmental Problems in Relation to Transport Global Pollution Study. Luxembourg EEC. 

The decrease in scientific activity on arylmercury and related arylated metal compounds is probably due to the lack of interest for technological purposes, and to the environmental problems which these compounds cause. 

Change the environment. We are used to solving environmental problems by relatively simple interventions adding fertilisers, pesticides and water. However, it is much more difficult to remove an excess than it is to supplement a deficiency. A technological solution to the salinity problem has many possibilities but all are costly. In the case of staple foods then either their market value (commercial) or the resources of their consumers (subsistence) precludes such a solution. 

Today s society asks for technology that has a minimum impact on the environment. Ideally, chemical processes should be clean in that harmful byproducts or waste are avoided. Moreover, the products, e.g. fuels, should not generate environmental problems when they are used. The hydrogen fuel cell (Chapter 8) and the hydrodesulfurization process (Chapter 9) are good examples of such technologies where catalysts play an essential role. However, harmful emissions cannot always be avoided, e.g. in power generation and automotive traffic, and here catalytic clean-up technology helps to abate environmental pollution. This is the subject of this chapter. 

Photocatalysis is a fundamental feature of life processes on our planet [1] (it provides photosynthesis in plants and bacteria) and of the chemistry of its atmosphere [2]. Work is under way to develop photocatalytic technologies for abatement of environmental problems [3,4]. Photocatalysis is anticipated to become in the coming years important also for selective organic synthesis [4]. In a more distant future thermal catalytic processes induced by heating with solcir radiation, together with photocatalytic processes may become important for environmentally friendly technologies of solar energy utilization [5-9]. 

There is a real opportunity to reduce biodiesel production costs and environmental impact by applying modem catalyst technology, which will allow increased process flexibility to incorporate the use of low-cost high-FFA feedstock, and reduce water and energy requirement. Solid catalysts such as synthetic polymeric catalysts, zeolites and superacids like sulfated zirconia and niobic acid have the strong potential to replace liquid acids, eliminating separation, corrosion and environmental problems. Lotero et al. recently published a review that elaborates the importance of solid acids for biodiesel production. ... 

In contrast to past environmental problems associated with fluorocarbon refrigerants, the exceptional properties of fluorine in polymers have great environmental value. Some fluoropolymers are enabling green technologies such as hydrogen fuel cells for automobiles and oxygen-selective membranes for cleaner diesel combustion. 

CPE X, the 20th anniversary meeting, was held in the city of CPE s birth, Lublin, Poland. Papers and posters on technology transfer novel, innovative and alternative treatment processes and environmental problems facing countries were presented. The meeting was enhanced by the participation of large delegations from both The Peoples Republic of China and the Taiwan Chinese Republic. 

The replacement of the diazonio group by metals and related transition elements was investigated intensively until the mid-20th century, particularly by Nesmeyanov and coworkers (reviews173). Most intensively studied were mercury-de-diazoniations. Since about 1970 there has been very little activity in the whole field of aryl-element chemistry as far as arenediazonium salts are involved. This decrease is probably due to the lack of interest for technological purposes, and to the environmental problem, which the synthesis and the use of the compounds cause. 

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