What are Hydrocarbons?
Hydrocarbons are organic compounds that are composed of carbon and hydrogen. These have four basic categories that include alkanes, alkenes, alkynes, and aromatics.
- Alkenes are saturated hydrocarbons that have the complete set of hydrogen attached to the carbons. Alkenes have the presence of a double bond (stronger bond, more energy than alkanes). Ethene or what is commonly known as ethylene is the most basic of all alkenes. Acetylene is the first in the series for alkenes.
- Alkynes are recognized by the presence of triple bonds.
- Aromatics are cyclic hydrocarbons.
- Petroleum is a mixture of hydrocarbons and its by-products.
- Alkanes have a single bond, and less energy than alkenes. The simplest of all alkanes is methane which has a chemical formula of CH4.
How are Hydrocarbons produced?
Production of hydrocarbons will only be limited to that of methane, ethylene, and acetylene. Methane can be produced naturally which has landfills, livestock, manure, and coal mining as some of the major sources of human-produced methane.
Ethylene is commercially produced by steam cracking. Groups of hydrocarbons are heated to produce products like olefins, propylene, and ethylene. Gas oil and naphta are the primary hydrocarbons used to manufacture ethylene.
The partial combustion of methane is the main procedure in manufacturing acetylene. It can also be produced from calcium carbide hydrolysis with the chemical reaction of CaC2 + 2H2O → Ca(OH)2 + C2H2.
How are Hydrocarbons stored and distributed?
A convenient and inexpensive way of storing methane is through the use of a mixture of silica and water. Tiny droplets from water are used to increase the surface area which comes in contact with the gas. This dry water powder rapidly soaks up a great quantity of methane.
Ethylene can be stored using a spherical or cylindrical tank. A “bullet” type of tank which could either be cylindrical, horizontal, and with hemiheads can be used for a small capacity of ethylene at around 250 psi at -250F.
Acetylene should be stored in gas cylinders with their valve end up and should be left in closed spaces. A minimum of 20 feet away from oxygen cylinders should separate the acetylene gas cylinders. Acetylene cylinders should not be hoisted using magnets, rope, or chain but by a net or in a box.
Uses of Hydrocarbons
Methane gas is used for fuel and for carbonizing steel. It is stable enough in that it does not react with common chemical reagents except for chlorine and fluorine in the presence of light. This characteristic makes it a good starting material for synthesis of solvents like methylene chloride, chloroform, carbon tetrachloride, and most refrigerants that use Freon.
Ethylene is used for the production of many solvents like polyethylene, ethylene glycol, and styrene.
Cutting and welding metals with the presence of oxygen is the use of acetylene.