NATURAL GAS Mostly Methane Natural gas is a

NATURAL GAS Mostly Methane • Natural gas is a fossil energy source that formed deep beneath the earth's surface. • Natural gas contains many different compounds. The largest component of natural gas is methane (CH 4). • It is composed principally of methane, but its composition varies greatly. Natural gas typically contains 60 to 80% methane, 5 to 9% ethane, 3 to 18% propane, and 2 to 14 % butane and pentane. 1

Where is natural gas found? In some places, natural gas moved into large cracks and spaces between layers of overlying rock. The natural gas found in these types of formations is sometimes called conventional natural gas 2

Where is natural gas found? In other places, natural gas occurs in the tiny pores (spaces) within some formations of shale, sandstone, and other types of sedimentary rock. This natural gas is referred to as shale gas or tight gas, and it is sometimes called unconventional natural gas. 3

Where is natural gas found? Natural gas also occurs with deposits of crude oil, and this natural gas is called associated natural gas. Natural gas deposits are found on land some are offshore and deep under the ocean floor. A type of natural gas found in coal deposits is called coalbed methane 4

How do natural gas find ? • Geologists often use seismic surveys on land in the ocean to find the right places to drill natural gas and oil wells. • Seismic surveys create and measure seismic waves in the earth to get information on the geology of rock formations. 5

Natural Gas Reserves Russia Ø Ø Ø Ø Ø Iran Oatar Turkmenistan United States of America Saudi Arabia United Arab Emirates Venezuela Nigeria Algeria 6

Movement of natural gas • There are three major types of pipelines along the transportation route: the gathering system, the transmission pipelines, and the distribution lines. • The gathering system includes low pressure, small diameter pipelines that transport raw natural gas from the production site to the processing plant, where it is purified and prepared for the end-use consumption. 7

Movement of natural gas • Transmission pipelines are large diameter, highpressure lines carrying large volumes of natural gas over long distances to consumption, or export hubs. • Distribution line system is the smaller diameter distance network that delivers natural gas to final consumers, including homes and business, but excluding large industrial users who are connected directly to the transmission system. 8

LNG - Liquefied Natural Gas • Natural gas can also be shipped over long distances as a liquid, known as liquefied natural gas, or LNG. • In order to transform natural gas into liquid phase, it has to be chilled to -160 C at atmospheric pressure. • This reduces the gas volume by 600 times and makes it possible to transport very large energy content over short and very long distances in specially-designed ocean tankers and trucks. 9

Uses of natural gas • Most natural gas is used as fuel, but it is also an important raw material. • Ethane and propane are cracked - decomposed by heat in the absence of air - to form ethylene and propylene. These alkenes are intermediates in the synthesis of plastics and many other useful commodities. • Natural gas is also the raw material from which methanol and many other one carbon compounds are made. 10

What is the equation for natural gas combustion? Ø Composed mainly of methane, natural gas burns with a relatively clean flame, and its products are mainly carbon dioxide and water. CH 4 + 2 O 2 CO 2 + 2 H 2 O Ø When natural gas is burned in limited amounts of air, carbon monoxide and even elemental carbon (soot) can be major products. 2 CH 4 + 3 O 2 2 CO + 4 H 2 O CH 4 + O 2 C + 2 H 2 O 11