据Gas Processing & LNG网站5月10日休斯顿报道，强劲的天然气产量以及快速增长的需求导致了美国天然气厂液化气（NGPL）产量再创历史新高，今年2月平均日产470万桶。作为烃气液(HGL )子集的液化气产量增长由产量也创下新纪录的乙烷引领，环比日增近13万桶。
由于原天然气在进入州际管道系统之前进行加工处理，液化气在天然气加工厂回收，并作为石油液体销售，与干天然气分离。虽然其他液化气完全从原天然气中回收以满足管道规格，乙烷在一定程度上仍可能存在于加工过的天然气中。丙烷、正丁烷、异丁烷和天然汽油的产量与天然气加工厂加工的原天然气产量密切相关；然而，从天然气中回收乙烷受到天然气产量和质量以及乙烷供需基本面因素的影响。
从2010年到2015年年中，以乙烷为原料的工业产能保持相当稳定。因此，即使天然气加工厂的丙烷和丁烷的产量和回收有所增长，乙烷的回收仍然相对持平。在此期间，液化气中乙烷的份额从40%以上下降到33%。
近年来，石油化工行业消费乙烷作为原料的能力有所提高，这导致美国国内乙烷市场扩大，乙烷出口支持了进一步的需求增长。因此，乙烷产量和乙烷在液化气中的份额都有所增加，以满足这一不断增长的需求。
EIA估计，由于新的乙烯裂解装置和现有设施的扩建，过去两年乙烷的国内需求每天增加36万桶。自美国西方化学公司(Occidental Chemicals) /墨西哥化工公司(Mexichem)在德克萨斯州英格尔塞德(Ingleside)的乙烯裂解装置于2017年投产以来，已有四家新的乙烯工厂投入运营。预计2019年将有四种新型裂解装置和一种主要的扩能装置投入使用，这意味着乙烷日需求量将再增加26万桶。此外，乙烷出口有望增加。
在《能源展望》(AEO 2019)年度报告中，EIA预测，由于美国天然气产量的增加和对液化气需求的增加，液化气产量将继续增长。2019年AEO预测液化气产量将在2030年超过600万桶/天(参照案例)，比2018年的水平高出40%，然后在预测期结束时逐渐下降到575万桶/天。EIA预计，由于石化行业的进一步增长，乙烷对未来液化气产量增长的贡献最大，占液化气总产量的比重将从2018年的40%提高到2050年的43%。东部地区包括阿巴拉契亚盆地，预计到2050年将占美国液化气产量的最大份额，占全国天然气总产量的30%，占美国所有乙烷产量的35%。
郝芬 编译自 Gas Processing & LNG
原文如下:
U.S. natural gas plant liquids production hits new record
Strong natural gas production, as well as rapidly-rising demand, resulted in record-high production of natural gas plant liquids (NGPL), which reached 4.7 million barrels per day (b/d) in February 2019. Growth in NGPL production, a subset of hydrocarbon gas liquids (HGL), was led by ethane, which also set a new record, which was nearly 130,000 barrels per day (b/d) higher than in the previous month.
Because raw natural gas is processed before it is introduced into the interstate pipeline system, NGPL are recovered at natural gas processing plants and marketed as petroleum liquids, separate from dry natural gas. Although other NGPL are recovered fully from raw natural gas to meet pipeline specifications, ethane may, to some degree, remain in processed natural gas. Propane, normal butane, isobutane, and natural gasoline production is closely tied to volumes of raw natural gas processed at gas processing plants; however, ethane recovery from natural gas is influenced by both the volume and quality of natural gas processed and ethane supply/demand fundamentals.
Between 2010 and mid-2015, industrial capacity to consume ethane as a feedstock remained fairly static. As a result, even as natural gas production and recovery of propane and butanes at natural gas processing plants grew, ethane recovery remained relatively flat. During this period, the ethane share of the NGPL barrel decreased from more than 40% to 33%. Recent growth in the petrochemical industry’s ability to consume more ethane as a feedstock has caused the domestic ethane market to expand, and ethane exports have supported further demand growth. Consequently, ethane production and ethane’s share of the NGPL barrel have increased to meet this rising demand.
EIA estimates domestic demand for ethane expanded by 360,000 b/d in the past two years as a result of new ethylene crackers and expansions of existing facilities. Since the Occidental Chemicals/Mexichem ethylene cracker at Ingleside, Texas, was commissioned in 2017, four new ethylene plants have entered service. Four new crackers and In the Annual Energy Outlook (AEO 2019), EIA projects this growth in NGPL production to continue as a result of increasing U.S. natural gas production and rising NGPL demand. The AEO 2019 projects NGPL production to exceed 6 million b/d in 2030 in the Reference Case—40% higher than the 2018 level—before gradually dropping to 5.75 million b/d at the end of the projection period. As a result of further growth in the petrochemical industry, EIA expects ethane to contribute the most to future NGPL production growth, increasing its share of total NGPL production from 40% in 2018 to 43% of all NGPL produced in 2050. The East region, encompassing the Appalachian Basin, is projected to account for the largest share of U.S. NGPL output―30% of the national total―and for 35% of all ethane produced in the United States in 2050.