Toluene is an aromatic hydrocarbon solvent and natural sources of toluene include crude oil and small quantities it is found in tolu tree.Toluene alternative names include methylbenzene, toluol, anisen, phenyl methane.Toluene is produced during the process of making gasoline and other fuels from crude oil, in making coke from coal, and as a by-product in the manufacture of styrene.
Toluene has numerous commercial and industrial applications and is a solvent in paints, lacquers, thinners, glues, correction fluid and nail polish remover, and is used in the printing and leather tanning processes. Methylbenzene can also be used as a fullerene indicator, and is a raw material for toluene diisocyanate.
Toluene as a solvent used in carbon nanotubes like fullerenes. It is also used as cement for fine polystyrene kits as. Biological usage of toluene includes breaking or disrupting red blood cells in order to extract hemoglobin in biochemistry experiments.
Toluene can be used as an octane booster in gasoline fuels used in internal combustion engines. Absolute toluene can be used as a fuel for both two-stroke and four-stroke engines.
One of the cosmetic and personal care products like nail products containing toluene are applied to the hard, largely impenetrable surface of the nail where a smooth and glossy film is quickly formed upon evaporation of the solvents.
Methylbenzene is used to manufacture benzene, urethane raw materials, and other organic chemicals. It is used in the production of pharmaceuticals, dyes, and cosmetic nail products. It is used in agricultural sector against roundworms and hookworms.
Toluene occurs naturally at low levels from crude oil and is usually produced in the processes of gasoline via a catalytic reformer, in an ethylene cracker or making coke from coal. It is widely used in industry, often as a substitute for benzene.
The methyl group which is present in methylbenzene makes it around 25 times more reactive than benzene in such reactions. Methylbenzene undergoes smooth sulfonation to give p-toluenesulfonic acid, and chlorination by Cl2 in the presence of FeCl3 to give ortho and para isomers of chlorotoluene.
Toluene may have local as well as systemic harmful effects. It may cause irritation of the eyes, respiratory tract, and skin. Repeated or prolonged contact with the liquid may cause removal of natural lipids from the skin resulting in dry, fissured dermatitis. Low-level, chronic exposure as well as acute exposure to toluene may result in central nervous system depression and decreased memory. Other symptoms include headache, dizziness, fatigue, muscular weakness, drowsiness, and incoordination with staggering gait, skin paresthesia, collapse, and coma.
The rate of polluted gases in the atmosphere comprises of dissolved organic compounds which affects the environment apparently. One of the best methods to reduce harmful gases in environment is bioreactors.The bioreactors are abundantly used to degrade those substances depending upon various parameters and suitable materials like packing material, microbes, etc. One such dissolved organic compound which is highly toxic to human beings and also present in the gaseous state is Toluene.
A bioreactor is a vessel in which a chemical process is carried out. This process can conducted either be aerobically or anaerobically. These bioreactors are commonly cylindrical, capacity ranging in size from litres to cubic metres, and are made of stainless steel material.
Bioreactor comprises of an
- Air compressor
- Oxygen tank
- Dehumidifier
- Activated carbon beds
- Dynamic system for the generation of BTX vapours
- Foam columns
- Cell reservoir
- Deformer
- Controlling devices
In the field of biochemical engineering, using various types of reactors, including an airlift loop reactor, a bubble column reactor, a stirred tank reactor, and a jet loop reactor etc.
Various techniques have been used for treating toluene
- Physiochemical treatment methods
- Bio filtration
- Bio degradation
- Thermal oxidation
- Catalytic oxidation
All these biological treatment methods can convert toluene into
- Carbon dioxide
- Water
- Salt
- Biomass
Jet loop reactor widely used bioreactor for Volatile organic compounds (VOCs) degradation.
Jet loop reactor
A jet loop reactor (JLR) contains a central draft tube inside the reactor. A bi fluid (liquid and gas) nozzle is located at the top or bottom of the reactor in a structure of two concentric cylinders. The gas delivered through one cylinder is dispersed by the liquid jet stream, delivered through the other cylinder.
The liquid or gas can be circulated back to the reactor to increase the concentration of the gas species in the liquid phase. In JLR toluene is absorbed by circulating nonionic surfactants which is of polyoxyethylene based (LA5 and LA7) Polyol- based and Surfactants.
The toluene removal efficiency was 70 per cent in Tween 81. The removal efficiency of toluene was not affected by Tween 81 which concentration is observed by effects of liquid flow rate. Dissolving oxygen in the water is found to be superior to other reactors interms of oxygen transfer rate per unit power input.
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