EIA:烃类液化气现货价格受油气市场影响

据7月23日Hydrocarbon Engineering报道，2020年3月快速下跌的原油价格和相对平稳(且处于历史低位)的天然气价格，这两个因素将烃类液化气（HGL）现货价格压缩至2020年3月中旬至4月底的狭窄价格区间。

随着原油价格上涨和天然气价格保持低位，这一相对狭窄的区间逐渐扩大。一般来说，HGL价格是基于其热容量，并被括在天然气价格下限和原油价格上限之间。

燃料的热含量反映了物理能量的燃烧所释放的热量，如每桶或每立方英尺燃烧释放的热能量。美国能源信息署(EIA)每月的能源审查提供了各种燃料的热含量信息，包括乙烷，它是HGL中最轻的，其热容量约为2.8百万英热/桶。

一般来说，乙烷的热含量与天然气相当。乙烷有两个碳原子，比天然气的主要成分甲烷多一个碳原子。乙烷供应的增长速度超过了石化工业将其作为原料消耗的能力。剩余的供应留在天然气流中，这往往会略微增加一立方英尺天然气的热含量。

丙烷是HGL中第二轻的物质，有3个碳原子。由于它可以很容易地替代其他燃料，如空间取暖、交通运输或石化原料，因此丙烷与其他石油产品的相似程度越来越高。与其它石油产品和国际丙烷市场相比，美国丙烷的过剩，以及到达出口市场的高昂运输成本，使美国丙烷大打折扣。

重质HGL的定价通常更接近原油。正丁烷和异丁烷广泛用于冬季车用汽油调合和生产高辛烷值汽油调合中。天然汽油是HGL中最重的一种，它至少含有五个碳原子，可以混合在汽车汽油中，也可以作为变性剂与乙醇混合。因为天然汽油在环境温度和压力下是液体，所以更容易运往海外。按热容量计算，天然汽油的价格通常接近原油。

王佳晶 摘译自 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.