Organic compounds dioxide

It must be kept under an atmosphere of nitrogen or carbon dioxide it reduces, for example, Fe(III) to Fe(II) and nitro-organic compounds RNO2 to amines RNH2 (it may be used quantitatively to estimate nitro-compounds). In neutral solution, hydrolysis occurs to give species such as [Ti(0H)(H20)s], and with alkali an insoluble substance formulated as Ti203 aq is produced this is rapidly oxidised in air. 

It will be apparent that this method depends for its success on the fact that all organic compounds, if oxidised under sufficiently vigorous conditions, may be converted quantitatively to water and carbon dioxide. 

Diethylene dioxide is a very useful solvent for a variety of organic compounds its action is similar to that of ether but more pronounced. It is miscible with water in all proportions. Dioxan vapour is poisonous. 

Organic compounds containing sulfur are very important. Calcium sulfur, ammonium sulfate, carbon disulfide, sulfur dioxide, and hydrogen sulfide are but a few of the many important compounds of sulfur. 

The deterrnination of hydrogen content of an organic compound consists of complete combustion of a known quantity of the material to produce water and carbon dioxide, and deterrnination of the amount of water. The amount of hydrogen present in the initial material is calculated from the amount of water produced. This technique can be performed on macro (0.1—0.2 g), micro (2—10 mg), or submicro (0.02—0.2 mg) scale. Micro deterrninations are the most common. There are many variations of the method of combustion and deterrnination of water (221,222). The oldest and probably most reUable technique for water deterrnination is a gravimetric one where the water is absorbed onto a desiccant, such as magnesium perchlorate. In the macro technique, which is the most accurate, hydrogen content of a compound can be routinely deterrnined to within 0.02%. Instmmental methods, such as gas chromatography (qv) (223) and mass spectrometry (qv) (224), can also be used to determine water of combustion. 

In 1990, a test using scrap tires (2x2 in. I DE) to generate steam for electricity was conducted at the Elexsys plant. The I DE replaced 20% of the plant s coal. Results showed that IDE is an environmentally sound fuel. Particulate emissions were reduced by the lower ash content of IDE, volatile organic compounds (VOC) were reduced because of more efficient burning of I DE compared to coal, and carbon dioxide emissions were reduced because I DE contains half the fixed carbon found in coal. Nitrogen oxide, chlorine emissions, and metals were also reduced, and ferrous metals and dioxins were nondetectable (7). 

Rhenium oxides have been studied as catalyst materials in oxidation reactions of sulfur dioxide to sulfur trioxide, sulfite to sulfate, and nitrite to nitrate. There has been no commercial development in this area. These compounds have also been used as catalysts for reductions, but appear not to have exceptional properties. Rhenium sulfide catalysts have been used for hydrogenations of organic compounds, including benzene and styrene, and for dehydrogenation of alcohols to give aldehydes (qv) and ketones (qv). The significant property of these catalyst systems is that they are not poisoned by sulfur compounds. 

Carbon. Most of the Earth s supply of carbon is stored in carbonate rocks in the Hthosphere. Normally the circulation rate for Hthospheric carbon is slow compared with that of carbon between the atmosphere and biosphere. The carbon cycle has received much attention in recent years as a result of research into the possible relation between increased atmospheric carbon dioxide concentration, most of which is produced by combustion of fossil fuel, and the "greenhouse effect," or global warming. Extensive research has been done on the rate at which carbon dioxide might be converted to cellulose and other photosyntheticaHy produced organic compounds by various forms of natural and cultivated plants. Estimates also have been made of the rate at which carbon dioxide is released to soil under optimum conditions by various kinds of plant cover, such as temperature-zone deciduous forests, cultivated farm crops, prairie grassland, and desert vegetation. 

Human-made sources cover a wide spectrum of chemical and physical activities and are the major contributors to urban air pollution. Air pollutants in the United States pour out from over 10 million vehicles, the refuse of over 250 million people, the generation of billions of kilowatts of electricity, and the production of innumerable products demanded by eveiyday living. Hundreds of millions of tons of air pollutants are generated annu ly in the United States alone. The five main classes of pollutants are particulates, sulfur dioxide, nitrogen oxides, volatile organic compounds, and carbon monoxide. Total emissions in the United States are summarized by source categoiy for the year 1993 in Table 25-10. 

Source category Particulate (PM-10) Sulfur dioxide Nitrogen oxides Volatile organic compounds Carbon monoxide... 

Combustion Many organic compounds released from manufacturing operations can be converted to innocuous carbon dioxide and water by rapid oxidation (chemical reaction) combustion. However, combustion of gases containing halides may require the addition of acid gas treatment to the combustor exhaust. 

---