Malodorants combustion

Flares are mostly used for the disposal of hydrocarbons. Waste gases composed of natural gas, propane, ethylene, propylene, butadiene, and butane probably constitute over 95 percent of the material flared. Flares have been used successfully to control malodorous gases such as mercaptans and amines, but care must be taken when flaring these gases. Unless the flare is very efficient and gives good combustion, obnoxious fumes can escape unburned and cause a nuisance. 

Elevated Flares See Flares for a general definition. The elevated flare, by the use of steam injection and effective tip design, operates as a smokeless combustion device. Flaring generally is of low luminosity up to about 20 % of maximum flaring load. Steam injection tends to introduce a source of noise to the operation, and a compromise between smoke elimination and noise is usually necessary. When adequately elevated (by means of a stack) this type of flare displays the best dispersion characteristics for malodorous and toxic combustion products. Visual and noise pollution often creates nuisance problems. Capital and operating costs tend to be high, and an appreciable plant area can be rendered unavailable for plant operations and equipment because of excessive radiant heat. 

General choice for total flare load, or as overcapacity flare In coniunction with multi)et flare. Generally the only acceptable flare where producu of combustion or partial combustion are toxic or malodorous. 

Suitable oitly for clean bunting gases, i.e. where products of combustion are not toxic or malodorous. 

Pollution Limitations - (i.e., smoke formation, malodorous or toxic combustion products, noise) which may be based on statutory and/or public relations requirements. 

Polysulphides are combustible, evolving sulphurous fumes, they are also malodorous. 

Some VOCs can be malodorous pollutants, sensory irritants, or hazardous air pollutants. Hazardous VOC air pollutants include acetaldehyde, benzene, carbon tetrachloride, chloroform, ethylbenzene, formaldehyde, hexane, methylene chloride, naphthalene, paradichlorobenzene, pesticides (biocides), styrene, tetrachloroethylene, toluene, trichloroethylene, and xylenes. They are found in essentially all indoor locations, released by off gassing from numerous sources, such as construction and decorating materials, consumer products, paints, paint removers, furnishings, carpets, and from combustion of wood, kerosene, and tobacco. While more than 500 VOCs have... 

The offensive odor of butanol can be removed from stack gases by its complete combustion to carbon dioxide and water. It is of interest that the incomplete combustion of butanol actually results in a more serious odor pollution problem than the original one. Write the equations showing the two intermediate malodorous products formed if butanol undergoes incomplete combustion. 

If the efficiency of destruction of the harmful substance is to be above 90%, then the residence time of the pollutants in the oxidation zone should be approximately 0.5 s and the temperature must not decrease below its limit value (500 to 650°C for the combustion of hydrocarbons and 750 C in the presence of carbon monoxide) and the destruction of malodorous substances require temperature above 800°C. Such thermal combustion can be employed in petroleum refining plants and in the petrochemical industry, for removing hydrocarbons from final gases, for removing vapours of solvents in the chemical and woodworking industry, and in steel works, etc. 

In considering issues related to combustion, malodor, or toxicity or chemical reactions, one generally requires (at least) the one-point probability density function. For example, the probability of ignition (PI) of, say, a methane gas cloud is given by the probability that, at a position located by vector x at time t, concentrations between the lower 0 and upper 0 flammability limits are encountered. That is. 

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