据路透社4月15日专栏报道——尽管近期的产量和需求数据，加上夏季旅行驾车需求的乐观前景，可能会为玉米生物燃料带来一些乐观情绪，美国玉米预估供应受乙醇产量拖累仍在向多年低点下滑。

　　在截至4月9日的四周内，美国乙醇产量平均日产量为95.1万桶，低于11月和12月的近期高点，较2017-2019年同期平均水平低6.6%。这种背离常态的结果仍是疫情后最好的结果。

　　最新的产量平均值反映出，与3月底的水平相比，产量略有下降，这在一定程度上与今年同期的季节性趋势一致。

　　2020年3月底，由于疫情的爆发，乙醇产量首次出现偏离典型水平，因此不应再进行同比比较。2020年之前的三年为“正?！碧峁┝艘桓隽己玫幕迹蛭馊臧艘桓銮磕瓴?、一个弱年产量和一个平均年产量。

　　由于近期需求超过产量，美国乙醇库存已跌至7年低点。截至4月9日，乙醇库存总计2,050万桶，两个月内减少了近16%。由于几乎所有的美国汽油都与生物燃料混合使用，因此汽油需求趋势与乙醇产量密切相关。上周，向市场供应的成品汽油平均每天为894万桶，是疫情期间情况良好程度排名第二的一周。最近四周，天然气需求仅比疫情爆发前的平均水平低6%，为疫情后的最小利润率。

　　在错过了2020年的假期后，美国人渴望在今夏出行。美国去年的旅游支出预计下降了42%，驾车率下降了13%，为2001年以来的最低水平。美国航空客运量下降了60%，为1984年以来的最低水平。

　　但是疫苗接种的进展和旅游预订的增加已经使夏天变得更加繁忙。美国航空 (American Airlines)周三表示，由于预订数量的增加，预计2021年夏季其国内航班的载客容量将超过90%。

　　根据美国疾病控制与预防中心的数据，截至周三，超过37%的美国人至少接种了一剂新冠疫苗，23%的人已完全接种。疫苗接种的速度一直在加快，按照目前的速度，到6月初，70%的人口可以接种疫苗。

　　上周，美国农业部将2020-21年度玉米乙醇使用量预估上调了2500万蒲式耳，至49.75亿蒲式耳，较2019-20年度的7年低点上涨2.4%。

　　从2016-17年开始，这一预测比前三个连续营销年平均下降了9%。自9月1日本销售年度开始以来，每周乙醇产量比这三年同期平均低了约9.5%。

　　夏季旅行的良好前景增加了乙醇产量和需求在年中进一步接近正常水平的可能性，不过随着经济持续从疫情中复苏，明年的产量将面临更大的争议。

　　美国农业部2月份暂定2021-22年度用于乙醇生产的玉米产量为52亿蒲式耳，较疫情爆发前水平下降约5%，不过该机构将于下月发布一份新的评估报告。这一数字的任何增加都将加大玉米供应的压力，其规模可能会比预计的2020-21年的7年低点还要小。

　　裘寅 编译自 路透社

　　原文如下：

　　U.S. ethanol trends slightly improve ahead of summer travel season

　　Projected U.S. corn supplies are still waning toward multi-year lows despite dragging ethanol output, though recent production and demand figures along with an upbeat outlook for the summer driving season should instill some optimism over the corn-based biofuel.

　　In the four weeks ended April 9, U.S. ethanol output averaged 951,000 barrels per day, off the recent highs observed in November and December and 6.6% below the 2017-2019 average for the same period. That departure from normal is a post-pandemic best.

　　The latest production average reflects a slight downturn from the late March levels, somewhat consistent with seasonal trends for the time of year.

　　Ethanol output first diverged from typical levels in late March 2020 due to the onset of the coronavirus pandemic, so year-on-year comparisons should no longer be made. The three years prior to 2020 provide a good baseline for “normal” since they contain one strong, one weaker and one average year of production.

　　With demand recently outpacing production, U.S. ethanol stocks have fallen to seven-year lows for the date. Stocks totaled 20.5 million barrels as of April 9, down nearly 16% in two months. Trends in gasoline demand track well with ethanol output since almost all U.S. gasoline is blended with the biofuel. Last week, finished motor gasoline supplied to the market averaged 8.94 million barrels per day, the second-best week in the virus era. In the latest four weeks, gas demand was just 6% below the pre-virus average, the smallest post-pandemic margin.

　　Americans are itching to get out this summer after largely missing out on vacations in 2020. Travel spending by Americans last year plunged an estimated 42% and U.S. driving fell by 13% to its lowest level since 2001. U.S. passenger airline traffic dropped 60% to the lightest since 1984.

　　But the vaccination progress and an increase in travel bookings are already setting up a much busier summer. American Airlines said on Wednesday it expects to fly more than 90% of its domestic seat capacity in the summer of 2021 based on a boost in reservations.

　　By Wednesday, more than 37% of Americans had received at least one dose of a coronavirus vaccine and 23% had been fully inoculated, according to the Centers for Disease Control and Prevention. The pace of vaccinations has been increasing, but 70% of the population could be vaccinated by early June at the current rate.

　　Last week, the U.S. Department of Agriculture increased its 2020-21 corn use for ethanol estimate by 25 million bushels to 4.975 billion bushels, up 2.4% from 2019-20’s seven-year low.

　　On average, that forecast is down 9% from the previous three uninterrupted marketing years starting with 2016-17. Since the start of the current marketing year on Sept. 1, weekly ethanol production has averaged about 9.5% below the same period in those three years.

　　Good prospects for summer travel increase the odds for ethanol output and demand to inch even closer to normal levels into mid-year, though next year’s volumes are subject to greater debate as the economy continues to recover from the pandemic.

　　USDA in February tentatively slated 2021-22 corn used for ethanol at 5.2 billion bushels, down about 5% from pre-virus levels, though the agency will issue a fresh assessment next month. Any increase in this number will amplify pressure to new-crop corn supplies, which could be even smaller than the seven-year low predicted for 2020-21.