Let's move away little from Oil to Natural Gas. Natural Gas is a naturally occurring hydrocarbon coming from fossils, just like Oil and Coal. The main components of Natural Gas as it comes from the reservoir are Methane (C1) and Ethane (C2) with varying amounts of heavier hydrocarbons that can include Propane (C3), Butane (C4), and Pentane (C5). Also, sometimes have small percentage of Carbon Dioxide, Nitrogen, Hydrogen Sulfide, or Helium.

Combustion of Natural Gas releases tiny amounts of Sulfur Dioxide and Nitrogen Oxides, and virtually no ash or particulate matter. The main products of the combustion of natural gas are Carbon Dioxide and Water Vapor, the same compounds we exhale when we breathe.

Here is a list of the several types of Natural Gas (Listed Alphabetically)

Coal Bed Methane (CBM): Natural gas extracted from coal beds.

Dry gas: Almost pure methane, occurring in the absence of liquid hydrocarbons or by processing natural gas to remove liquid hydrocarbons.

Liquefied Natural Gas (LNG): Natural gas that is converted into a liquid by refrigerating it to -160°C and reducing its volume by 600 times, enabling it to be shipped from producing areas to markets. LNG is destined to become a massively significant part of the Global Energy equation over the coming years.

Natural Gas: Naturally occurring Hydrocarbon Gases found in porous rock formations.

Natural Gas Liquids (NGLs): A general term for highly volatile liquid products separated from Natural Gas in a gas processing plant. NGLs include Ethane, Propane, Butane and Condensate.

Sour Gas: A Natural Gas containing significant amounts of Hydrogen Sulfide.

Sweet Gas: Natural gas that contains little or no Hydrogen Sulfide.

Tight Gas: Natural gas produced from impermeable rock. Getting tight gas out usually requires enhanced technology applications like Hydraulic Fracturing. The term is generally used for reservoirs other than shale.

Wet Gas: Produced Gas that contains Natural Gas Liquids.

Natural Gas has the cleanest combustion profile of all the fossil fuels.