Esters - alcohol derivatives whose molecules hydrogen atom is substituted with an OH group on the carbon radical.For typical metamerism esters and isomers hydrocarbon chain.
isomerism due to its hydrocarbon chain branching.
Metamerism - view of isomerism in which two or more esters have a similar molecular formula but a different molecular structure, due to different radicals on both sides of the oxygen "bridge".For example, the molecular formula S4N10O meet three ether:
- CH3-O-CH (CH3) 2;
- CH3-O-C3H7;
- C2H5-O-C2H5.
These substances are produced synthetically, including dimethyl ether.The formula of this compound is represented by two methyl radicals, which are linked by oxygen "bridge".
It should be noted that the nature thereof, in the free state are not encountered.Dimethyl ether and methyl ethyl - gases.The next few representatives - liquid while higher esters - solids.They are very poorly soluble in water, well in organic solvents.Average representatives (dipropyl, propiletilovy diethyl) - excellent organic solvents.Physical properties of these organic compounds vary depending on the molecular weight.
Dimethyl ether Preparation of
describes a substance is highly soluble in water, ethanol, diethyl and dipropyl ether.This ester is obtained due to dehydration and methanol as a byproduct of the production of methanol from CO and H2.Used in refrigeration as refrigerant.
In the near future, diesel engines will be transferred no gas, and dimethyl ether.Such a reconstruction of their cost is much cheaper compared to the transition to natural gas.The leading countries in the production of these engines are the US, Russia and Japan.
In the early 21st century, the Russian government made a decision on the use of alternative fuels in road transport.Dimethyl ether is used in trucks.Such a radical decision was made due to the fact that emissions of nitrogen compounds from diesel engines installed in trucks that exceed the established norm in a few times.Dimethyl ether is ideal for this type of engine, they practically do not need to be reconstructed.Only through the use of new alternative fuel new upgraded engine reached the level of Euro-3 ecological.
Governments around the world are confident that the fuel of the future for diesel engines is dimethyl ether.Today this material was prepared essentially by the processing of natural gas.In the first stages of the process lends itself to reforming natural gas, thereby producing a synthesis gas.Thereafter, it is converted into methyl alcohol.Further amenable methanol dehydration, thereby obtaining dimethyl ether.There is another method for the synthesis of this ester - direct conversion of synthesis gas to methanol.
esters compared to diesel fuel have advantages and, of course, disadvantages.The molecules lacking ester "carbon-carbon" bond.Due to a significant oxygen content ensures good atomization in the Ether in an environment with a temperature above the boiling point of t matter.These characteristics improve combustion.Through the application of this alternative fuel engine noise is reduced, thus increasing its reliability.
The main disadvantages of this ester include lower calorific value and lower density.All this leads to an increase in fuel consumption.This matter is very poor lubricating properties.
