主题:【讨论】现代战国策---美国的乙醇战略zt -- 泡菜
下面文章是真正的乙醇专家在SCIENCE上发的文章,你看看他怎么联系乙醇和石油的。你发文到SCINCE去指责他误导吧。可惜现在乙醇界都这样比较的,因为你不明白现在的乙醇就是这么生产的。在乙醇生产过程中,蒸发提纯耗掉了60%的能量,现在这些能量不是烧乙醇得来的,而是烧天然气得来的。在你那篇文章<生产生物乙醇的消耗>中对这一最大的能量消耗完全不提,也可见你这专家的水平了。
In their Report "Ethanol can contribute to energy and environmental goals" (27 Jan., p. 506), A. E. Farrell and colleagues offer hopeful opinions about corn-based ethanol. Their analysis suggests that, since the ratio of ethanol produced to fossil fuel used is positive, ethanol should be further developed. If replacing oil is our goal, we must look
at two parameters of this approach: (i) energy return on investment (EROI) including environmental impacts on soil, water, climate change, ecosystem services, etc.; and (ii) scalability and timing. Farrell and colleagues' most optimistic EROI of 1.2:1 (which does not include tractors, labor, or environmental impacts) implies that we need to produce 6 MJ of ethanol to net 1 MJ of energy for other endeavors.
Thus,the yield of ethanol would not be 360 gallons per acre gross yield, but rather a mere 60 gallons per acre net yield, not even two fill-ups for an SUV. The entire state of Iowa, if planted in corn, would yield approximately five days of gasoline alternative. To devote half the nation's corn crop to ethanol would require an input of 3.42 billion barrels of oil (almost half our current national use)
to net 684 million barrels of "new" ethanol energy. We would also lose food and soil nutrients, suffer ecosystem damage, and use massive amounts of water for irrigation.
We need alternative energy. But ethanol from corn is neither scalable nor sustainable. Let's pursue better options.
In their Report "Ethanol can contribute to energy and environmental
goals" (27 Jan., p. 506), A. E. Farrell and colleagues offer hopeful
opinions about corn-based ethanol. Their analysis suggests that, since
the ratio of ethanol produced to fossil fuel used is positive, ethanol
should be further developed. If replacing oil is our goal, we must look
at two parameters of this approach: (i) energy return on investment
(EROI) including environmental impacts on soil, water, climate change,
ecosystem services, etc.; and (ii) scalability and timing. Farrell and
colleagues' most optimistic EROI of 1.2:1 (which does not include
tractors, labor, or environmental impacts) implies that we need to
produce 6 MJ of ethanol to net 1 MJ of energy for other endeavors.
Thus,
the yield of ethanol would not be 360 gallons per acre gross yield, but
rather a mere 60 gallons per acre net yield, not even two fill-ups for
an SUV. The entire state of Iowa, if planted in corn, would yield
approximately five days of gasoline alternative.
To devote half the nation's corn crop to ethanol would require an input
of 3.42 billion barrels of oil (almost half our current national use)
to
net 684 million barrels of "new" ethanol energy. We would also lose
food
and soil nutrients, suffer ecosystem damage, and use massive amounts of
water for irrigation.
We need alternative energy. But ethanol from corn is neither scalable
nor sustainable. Let's pursue better options.
Nathan Hagens
Gund Institute for Ecological Economics
University of Vermont
Burlington, VT 05405,
Gund Institute for Ecological Economics
University of Vermont
Burlington, VT 05405,
- 相关回复 上下关系8
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🙂实际情况可能更糟 1 橡树村 字640 2008-02-15 03:52:42
🙂我倒觉得该文作者相当内行 可怜的土豆 字3002 2008-02-15 09:59:29
🙂错就错在这句把化石能源转化成乙醇能源 橡树村 字352 2008-02-15 11:02:13
🙂你看看真正的专家在SCIENCE上是怎么讨论乙醇问题的
🙂你还是仔细看看我怎么讲的吧 1 橡树村 字1104 2008-02-15 12:34:57
🙂OK,你的下两篇续里是说了蒸发能量损耗,是我没往下翻 可怜的土豆 字799 2008-02-15 14:19:59
🙂你终于肯好好看帖子了 橡树村 字108 2008-02-15 18:16:37
🙂村长真是专家 中国陈 字54 2008-02-15 04:12:10