據7月23日Hydrocarbon Engineering報道，2020年3月快速下跌的原油價格和相對平穩(且處于歷史低位)的天然氣價格，這兩個因素將烴類液化氣（HGL）現貨價格壓縮至2020年3月中旬至4月底的狹窄價格區間。

隨著原油價格上漲和天然氣價格保持低位，這一相對狹窄的區間逐漸擴大。一般來說，HGL價格是基于其熱容量，并被括在天然氣價格下限和原油價格上限之間。

燃料的熱含量反映了物理能量的燃燒所釋放的熱量，如每桶或每立方英尺燃燒釋放的熱能量。美國能源信息署(EIA)每月的能源審查提供了各種燃料的熱含量信息，包括乙烷，它是HGL中最輕的，其熱容量約為2.8百萬英熱/桶。

一般來說，乙烷的熱含量與天然氣相當。乙烷有兩個碳原子，比天然氣的主要成分甲烷多一個碳原子。乙烷供應的增長速度超過了石化工業將其作為原料消耗的能力。剩余的供應留在天然氣流中，這往往會略微增加一立方英尺天然氣的熱含量。

丙烷是HGL中第二輕的物質，有3個碳原子。由于它可以很容易地替代其他燃料，如空間取暖、交通運輸或石化原料，因此丙烷與其他石油產品的相似程度越來越高。與其它石油產品和國際丙烷市場相比，美國丙烷的過剩，以及到達出口市場的高昂運輸成本，使美國丙烷大打折扣。

重質HGL的定價通常更接近原油。正丁烷和異丁烷廣泛用于冬季車用汽油調合和生產高辛烷值汽油調合中。天然汽油是HGL中最重的一種，它至少含有五個碳原子，可以混合在汽車汽油中，也可以作為變性劑與乙醇混合。因為天然汽油在環境溫度和壓力下是液體，所以更容易運往海外。按熱容量計算，天然汽油的價格通常接近原油。

王佳晶 摘譯自 Hydrocarbon Engineering

原文如下：

EIA: hydrocarbon gas liquids spot prices are generally bound by crude oil and natural gas

The combination of rapidly declining crude oil prices in March 2020 and relatively flat (and historically low) natural gas prices compressed hydrocarbon gas liquids (HGL) spot prices into a narrow price band from mid-March through the end of April 2020.

This relatively narrow band has since widened as crude oil prices have increased and natural gas prices have remained low. Generally, HGL prices are based on their heat content and are bracketed by the prices of natural gas (the lower bound) and crude oil (the upper bound).

The heat content of a fuel reflects the amount of heat energy released by the combustion of a physical measure of energy, such as a barrel or cubic foot. The US Energy Information Administration’s (EIA) Monthly Energy Review provides information on the heat content of various fuels, including all HGLs. For example, ethane, the lightest HGL, has an approximate heat content of 2.8 million Btu/bbl.

Ethane generally costs about as much as natural gas on a heat-content equivalent basis. Ethane has two carbon atoms, which is one more carbon atom than methane—the primary constituent of natural gas. The supply of ethane has grown more rapidly than the petrochemical industry's ability to consume it as a feedstock. The remaining supply is left in the natural gas stream (a process referred to as ethane rejection), which tends to slightly increase the heat content of a cubic foot of natural gas.

Propane, the second-lightest HGL, which has three carbon atoms, has trended closer to other petroleum products because it can easily be substituted for other fuels for such uses as space heating, transportation, or petrochemical feedstock. A surplus of US propane and high transportation costs to reach export markets have discounted US propane compared with other petroleum products and international propane markets.

Heavier HGLs typically are priced closer to crude oil. Normal butane and isobutane are widely used in motor gasoline blending in the winter and to produce high-octane gasoline blending components. Natural gasoline, the heaviest HGL, has at least five carbon atoms and can be blended into motor gasoline throughout the year or blended with ethanol as a denaturant (which makes the ethanol unfit for human consumption). Because natural gasoline is a liquid at ambient temperature and pressure, it can more easily be shipped overseas. Natural gasoline is often priced close to crude oil on a heat content basis.