What are natural gas liquids and how are they used?

Posted on February 17, 2015

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NGL-2

IEA demand

When the International Energy Agency, IEA, presents its future scenarios, Natural Gas Liquids, NGL, are present as an important component. The IEA’s most recent graph describing its New Policies Scenario was presented in its World Energy Outlook 2012 (WEO 2012) report. In that graph we can see that the production component volume that is currently increasing most rapidly is NGL. It is a little difficult to think of NGL (a heavy gas) as resembling crude oil, the type of oil one normally associate with the word “oil”. But when the media reports on daily oil production they are usually describing the sum total of the list of liquid products counted as oil by the IEA and that includes NGL. The list also includes “processing gains” that is simply the increase in the total volume of oil products as crude oil is separated into various fractions in a refinery. The latest addition to the IEA’s list of oil contributors is “Light Tight Oil” (LTO). This has the same chemical characteristics as conventional crude oil and was first classed as conventional oil but in WEO 2013 LTO landed in the unconventional class.

Liquide support WEO 2011 fig 3

In the diagram above you can see that “refinery processing gains” are not regarded as oil production, the substance I usually discuss and research into. In the diagram, conventional oil includes only crude oil and NGL. It is important not to confuse NGL with LNG (liquid natural gas) that is natural gas (methane) that has been cooled to a very low temperature so that it condenses from a gas into a liquid. The USA’s energy authority, the Energy Information Administration (EIA) produced an information page on NGL in 2012, NGL – What are natural gas liquids and how are they used? The following table is from that information page and I have also copied some of the text from that page below:

NGL
Source: U.S. Energy Information Administration, Bentek Energy LLC.

“Natural gas liquids (NGLs) are hydrocarbons—in the same family of molecules as natural gas and crude oil, composed exclusively of carbon and hydrogen. Ethane, propane, butane, isobutane, and pentane are all NGLs (see table above). There are many uses for NGLs, spanning nearly all sectors of the economy. NGLs are used as inputs for petrochemical plants, burned for space heat and cooking, and blended into vehicle fuel.
The chemical composition of these hydrocarbons is similar, yet their applications vary widely. Ethane occupies the largest share of NGL field production. It is used almost exclusively to produce ethylene, which is then turned into plastics. Much of the propane, by contrast, is burned for heating, although a substantial amount is used as petrochemical feedstock. A blend of propane and butane, sometimes referred to as “autogas,” is a popular fuel in some parts of Europe, Turkey, and Australia. Natural gasoline (pentanes plus) can be blended into various kinds of fuel for combustion engines, and is useful in energy recovery from wells and oil sands.”

The text above indicates that the largest part of NGL is used in the petrochemical industry. The NGL component propane is said to be used in “Commercial Heating” and one important such use is to heat up oil in refineries. An important use for the heavier NGL components is to blend them into the very viscous oil from the oil sands in Canada so that it can flow more easily and be transported through pipelines. Some heavier NGL components are also used as vehicle fuel. When one sees how NGL and crude oil are blended and used to make finished products for the transport sector it is easier to accept NGL production as part of conventional oil production. But ethane, that is the largest component of NGL, is mostly not used in transport.

Any future increase in transport fuel volumes is completely dependent on unconventional oil, LTO, discovery of new oilfields and large investments in oilfields already discovered. In recent weeks the oil industry has indicated that it will reduce investment in all four of these sectors.

The IEA has also released a report on NGL:
Natural Gas Liquids – Supply Outlook 2008-2015

(Parts with Swedish text)

IEA demand

Då IEA (International Energy Agency) presenterar sina framtidsscenarier finns NGL (Natural Gas Liquides) med som en viktig komponent. Den senaste grafen som IEA presenterar på sitt New Policies Scenario visades i WEO 2012 (World Energy Outlook 2012). Vi ser att den del som ökar mest är just NGL. Det är lite svårt att ta till sig att NGL är olja då vi vanligen tänker på råolja (crude oil) då någon nämner eller skriver ordet olja. Då media rapporterar om dagens oljeproduktion är det oftast just IEA:s sammanlagde lista av flytande produkter som kallas olja. Man har också med ”processing gains” som är den volymsökning som produkterna ut från ett raffinaderi har jämfört med volymen in. Senaste tillskottet på listan är ”Light Tight Oil” (LTO). LTO har samma kemiska egenskaper som Crude Oil (konventionell olja) och klassades först som konventionell olja, men i WEO 2013 hamnade LTO som okonventionell olja.

Liquide support WEO 2011 fig 3

I grafen ser vi att ”refinery processing gains” inte betraktas som produktion av olja, den volym som jag normalt diskuterar och forskar om. Kvar som konventionell olja har vi nu råolja (crude oil) och just naturligt flytande gas (NGL). Det är viktigt att inte förväxla NGL med LNG (Liquefied natural gas) som är naturgas som kyls ner till en temperatur där den har en fasövergång från gas till flytande vätska.

USA:s energimyndighet EIA (Energy Information Administration) gjorde 2012 en informationssida om NGL – What are natural gas liquids and how are they used? Följande tabell är från deras informationssida och jag har också kopierat en del av texten.

NGL
Source: U.S. Energy Information Administration, Bentek Energy LLC.

“Natural gas liquids (NGLs) are hydrocarbons—in the same family of molecules as natural gas and crude oil, composed exclusively of carbon and hydrogen. Ethane, propane, butane, isobutane, and pentane are all NGLs (see table above). There are many uses for NGLs, spanning nearly all sectors of the economy. NGLs are used as inputs for petrochemical plants, burned for space heat and cooking, and blended into vehicle fuel.
The chemical composition of these hydrocarbons is similar, yet their applications vary widely. Ethane occupies the largest share of NGL field production. It is used almost exclusively to produce ethylene, which is then turned into plastics. Much of the propane, by contrast, is burned for heating, although a substantial amount is used as petrochemical feedstock. A blend of propane and butane, sometimes referred to as “autogas,” is a popular fuel in some parts of Europe, Turkey, and Australia. Natural gasoline (pentanes plus) can be blended into various kinds of fuel for combustion engines, and is useful in energy recovery from wells and oil sands.”

Av texten här ovan framgår det att större delen av NGL används inom den petrokemiska industrin. För propan nämns ”Commersial Heating” och en viktig användning är att värma upp oljan i ett raffinaderi. En viktig användning för de tyngre flytande gaserna är som nämns att man blandar dem med den tunga oljan från oljesanden i Kanada så att man får en flytande vätska som kan transporteras i en pipeline. En del används också direkt som bilbränsle. Då man ser hur användningen av råolja och NGL blandas och används för att få slutprodukter för transportsektorn är det lättare att acceptera att NGL är konventionell olja. Men etan, som är större delen av NGL kommer inte att användas för bränsle för transporter.

Ökning av fransportbränsle är helt beroende av okonventionellolja, light tight oil, att man hittar nya oljefält och att man investerar stort i de fält som man redan hittat. De senaste veckorna har oljeindustrin signalerat att man kommer att minska sina investeringar inom samtliga fyra sektorer.

IEA har också gjort en rapport om NGL,

Natural Gas Liquids – Supply Outlook 2008-2015

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