Environmental friendly methods

Addresses conventional production technologies as well as new, environmentally friendly methods... 

The most important progress in the chemistry of nitro compounds is the improvement of their preparations this is discussed in chapter 2. Environmentally friendly methods for nitration are emphasized here. 

Until the use of more environmentally friendly methods of preservation are used as standard throughout the lumber industry, you may prefer to ask a sawmill or fencing supplier to supply untreated wood. You can treat this yourself using eco-friendly products based on natural plant oils, resins, and other less toxic materials. 

A Convenient, Inexpensive, and Environmentally Friendly Method of Measuring the Vapor Pressure of a Liquid as a Function of Temperature 204... 

Viani, Lisa Owens. Don t Flush the Ambien Environmentally-Friendly Prescription Drug Disposal, San Mateo County, Calif. Utne Reader 146 (March/April, 2008) 82. To help protect water supplies and landfills from leakage of disposed prescription drugs, San Mateo has devised some environmentally friendly methods of disposal. According to the article, the country has set up a drop-off system for unused drugs and hopes other counties will adopt similar programs. 

Obviously there is a definite need in the fine chemical and pharmaceutical industry for catalytic systems that are green and scalable and have broad utihty [10]. More recently, oxidations with the inexpensive household bleach (NaOCl) catalyzed by stable nitroxyl radicals, such as TEMPO [17] and PIPO [18], have emerged as more environmentally friendly methods. It is worth noting at this juncture that greenness is a relative description and there are many shades of green. Although the use of NaOCl as the terminal oxidant affords NaCl as the by-product and may lead to the formation of chlorinated impurities, it constitutes a dramatic improvement compared to the use of chromium(VI) and other... 

Gordon, G. Bubnis, B. Environmentally Friendly Methods of Water Disinfection The Chemistry of Alternative Disinfectants, Progr. Nucl. Energy 2000, 37 (1—4) 37-40. 

Supercritical fluid extraction has been applied to extract phenolic acids from a variety of plant samples. It uses high-pressure to force carbon dioxide to be a mixture of liquid and gas phases, which is called a supercritical fluid. The liquid and gas phase mixture of carbon dioxide can more readily permeate the sample matrix than only the gas phase of carbon dioxide. The compounds solublized in the liquid phase of carbon dioxide are extracted from the sample matrix and collected after they elute from the outlet of the system. The biggest advantage of supercritical fluid extraction is that there is no, or less, organic solvent involved in the extraction, due to the use of carbon dioxide supercritical fluid as the major solvent.. The carbon dioxide readily evaporates as gas phase at the system outlet. Thus, unlike other solvent extraction methods, there is no evaporation step for the extraction, making this an environmentally friendly method. However, the system is much more expensive and delicate than the other novel technology extraction... 

PTE was also entrapped in additives for latex coating of biodefensive surfaces. Such PTE-based additives for paints and coatings were shown to retain catalytic parameters and stability of the enzyme (McDaniel et al, 2006). For decontamination of OPs in the environment and remediation, an alternative approach, phytodegradation by transgenic plants (e.g. tobacco) expressing a bacterial PTE, has been considered as a potentially low-cost, effective, and environmentally friendly method (Wang et al, 2008). 

The development and use of environmentally friendly methods for the synthesis of quinolines and dihydroquinolines were represented in variety of publications in 2006. Many of the reports incorporated solvent free conditions. Perumal et al. showed that silica-supported NaHSO as a heterogeneous catalyst for the cyclization of 2-amino-chalcones 71 under solvent free microwave conditions results in a variety of 2,3-dihydroquinolin-4-ones 72 in high yields <06CJC1079>. Lier et al. also utilized a silica supported TaBrs catalyst to cyclize 2-amino-chalcones 71 forming a variety of 2,3-dihydroquinolin-4-ones 72 under solvent free thermal conditions <06TL2725>. The use of silica gel supported TaBrs under solvent free thermal conditions showed considerable improvement in yield for this cyclization compared to the reaction conducted in organic solvents. 

The research that involves the end-of-process treatments to eliminate pollutants is termed green chemistry. As Ronald Breslow (Columbia University) pointed out, concern for the environment is as old as the biblical injunction, hurt not the earth, neither the sea, nor the trees. The following example indicates approaches to the environmentally benign chemistry. The process described is high yielding with water as the by-product. Sato et al. have developed an efficient, environmentally friendly method for oxidizing primary and secondary alcohols (Scheme 8). The Japanese... 

The use of liquid water at a high temperature and pressure provides a promising alternative to other sample pretreatments as this is the ideal solvent for developing environmentally friendly methods. Water at a high pressure and temperature has traditionally been called subcritical water however, the term superheated water is probably more accurate to refer to water heated above 100°C and subjected to the pressure required to keep it in the liquid state as subcritical water can be any water below the critical point... 

Alkene epoxidation is a very useful reaction in industry and organic s)mthesis. The resultant epoxides are essential precursors in the s)mthesis of various important substances like plasticizers, perfumes, and epoxy resins [1]. For example, over 5,000,000 and 70,000 metric tonnes of propylene and butene oxides, respectively, are produced per year [2]. Current commercial production of propylene oxide (PO) usually employs the chlorohydrin process or the Halcon process, which gives rise to disposal problem for the resultant salts or large amounts of coproducts. As a result of increasing stringent enviromnent legislation, there is currently much interest in the research and development of environmentally friendly methods for preparation of PO without any coproduct. 

We have developed an economical and environmentally friendly method of producing TAA with extremely high selectivity using ammonium nitrate, ammonium hydroxide, and acetone in the presence of a calcium containing acid catalyst. 

Researchers are constantly looking for new, more efficient, more environmentally-friendly methods for making acetic acid. In 2003, for example, chemists at the University of Southern California reported on a new method for making acetic acid directly from methane gas (CH4) using a catalyst of palladium and sulfuric acid. Other researchers are looking for ways to oxidize the waste gases produced from industrial processes to acetic acid. 

The science of organic synthesis revolves around the development of newer strategies and methodologies which are more efficient, greener, practical, and safe. Despite the fact that there has been dramatic success in the past few decades in the area of development of newer and environmentally friendly methods, one is not able to synthesize everything that is needed. In fact, in the literature there are more unconquered complex targets than already synthesized targets. There are several complex bioactive and most wanted natural products that are either conquered but not with optimum efficiency or that have never been synthesized. ... 

J. J. H. Edema. Environmentally friendly method for poly(phenylene ether) polymerization and catalyst recycle. US Patent 5 621066, assigned to General Electric Company (Pittsfield, MA), April 15, 1997. 

Novel applications in science and technology require highly efficient and, if possible, environmentally friendly methods and techniques for the generation of functional nanocomposite materials. Serving the environmental aspect, water-based formulation techniques that avoid the use of organic solvents are the focus of attention. Besides the well-known water-based emulsion and mlcroemul-sion polymerization processes, the miniemulsion polymerization technique is a highly versatile heterophase system that is suitable for the preparation of complex nanoparticles. 

Glasovac Z, Troselj P, JuSinski I, Margetic D, Eckert-Maksi6 M. Synthesis of highly basic hexasubstituted biguanides by environmentally friendly methods. S5mlett 2013 24 2540-4. 

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