Toluene flammability limit

Air stripping is used to remove 90% of the toluene (molecular weight = 92) dissolved in a 10 kg/s (159 gpm) wastewater stream. The inlet composition of toluene in the wastewater is 500 ppm. Air (essentially free of toluene) is compressed to 202.6 kPa (2 atm) and bubbled through a stripper which contains sieve trays. In order to avoid fire hazards, the concentration of toluene in the air leaving the stripper is taken as 50% of the lower flammability limit (LFL) of toluene in air. The toluene-laden air exiting the stripper is fed to a condenser which recovers almost all the toluene. A schematic representation of the process is shown in Fig. 2.11. Calculate the annual operating cost and the fixed capital investment for the system. The following physical and economic data are available ... 

Lower flammability limit for toluene in air is 12,000 ppm (Growl and Louvar, 1990). 

Propargyl Bromide (3-Bromo-l-propyne). HC=CCH2Br mw 118.97 colorl to faintly brownish liq mp 24.4° bp 88—90° d 1.52 g/cc RI 1.4320 at 20°. Sol in ale, eth, benz chlf. Flammable flash pt 10° (closed), 18° (open) ignition temp 328° lower flammable limit 3.0%. It can be decompd by mild shock. When heated under confinement, it decomps with expl violence and may detonate. When suitably diluted, as with 20—30% by wt of toluene, its expl properties are practically eliminated (Ref 4)... 

Example Estimate the lower and upper flammability limits of toluene. 

The temperature at which the vapor in equilibrium with the standard atmosphere above a pool of that liquid is at the lower flammability limit. Reported as open-cup or closed-cup. For materials that vaporize rapidly, the two values are about the same. For materials that vaporize slowly the closed-cup temperatures are always less than open-cup data because of the conditions of the test. Benzene -11.15°C toluene 4.0°C. 

Flammable permanent gases and vapours have well-defined flammability limits in air, usually in the range l-35 5F v/v" "2. Many hydrocarbons such as toluene and xylene can also bum in atmospheres such as chlorine. ... 

This indicates that crude oils (meeting the criteria outlined in paragraph 6) and toluene also have the potential to form a large vapour cloud in the event of an overfill. For toluene, the cloud concentration at the base of a tank has been shown by research to be just above its lower flammable limit. However, there is a degree of uncertainty over whether its subsequent movement and dilution would lead to the formation of a large flammable vapour cloud. Taking a precautionary approach it would seem sensible to consider that it would. 

Tables 16 and 17 Hst tke analytical test methods for different properties of interest. The Manufacturing Chemists Association, Inc. (MCA) has pubUshed the Chemical Safety Data Sheet SD 63, which describes in detail procedures for safe handling of use of toluene (46). The Interstate Commerce Commission classifies toluene as a flammable Hquid. Accordingly, it must be packaged in authorized containers, and shipping must comply with ICC regulations. Properties related to safe handling are autoignition temperature, 536°C explosive limits, 1.27—7.0 vol % in air and flash point 4.4°C, closed cup.

The xylenes are flammable and are shipped under the same regulations and using the same methods as benzene and toluene rank cars, trucks, barges, and tankers. Pipeline movements are limited. Toxicological problems dictate handling in closed systems like benzene and toluene. 

Polyalumophenylsiloxane varnish is a solution of polyalumophenylsiloxane in a mixture of toluene and butanol. Its flammability, boiling point and inflammation point, as well as explosive limits of varnish vapours mixed with air, mostly depend on the properties of the solvents used. 

METHACIDE (108-88-3) see toluene. METHYLACRYLALDEHYDE or a-METHYLACRYLALDEHYDE (78-85-3) C4HSO CH2=C(CH3)CH0 Highly flammable, polymerizable hquid. Forms explosive mixture with air [explosion limits in air (vol %) 2.6 to uel unknown flash point... 

Xylene (mixture of a-, m-, jg-dimethylbenzenes [CAS 1330-20-7]) Vapors irritating to eyes and respiratory tract. A CNS depressant. By analogy to toluene and benzene, may cause cardiac arrhythmias. May Injure kidneys. Limited evidence for adverse effects on fetal development in test animals at very high doses. See also p 357. too ppm 900 ppm 2 3 0 Colodess llguid or solid. Weak, somewhat sweet, aromatic odor. Irritant effects are adeguate warning properties. Vapor pressure is approximately 8 mm Hg at 20 C (68°F). Flammable. 

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