Under the new rule, by 2015, existing boilers must switch from No. 6 oil to a low-sulfur version of the No. 4 heating oil or to an equivalent cleaner fuel.

按照这项新法规，截止2015年，现存锅炉必须由6号燃料油换成4号低硫型燃料油或与之相当的较为清洁的燃料。

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To clean up the air, California is the only state in the U.S. to require all ships to use low-sulfur fuel when they are within 44 kilometers of the shore.

为了清洁空气，加利福尼亚规定所有船只，在驶进距离岸边44公里范围内时，必须使用低含硫量燃料。美国各州中只有加州是这么规定的。

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Biomass biomass boiler precipitator fuel is a renewable source of carbon, with great production, wide distribution, low sulfur, low nitrogen, fast growth, low carbon dioxide emissions.

生物质锅炉除尘器生物质燃料是可再生的碳源，具产量巨大、分布广泛、低硫、低氮、生长快、二氧化碳排放低的特点。

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With production capacity for high-quality, low-sulfur crude offline in Libya, Yemen and Sudan, the cartel is unable to compensate.

FORBES: Could We See A Summer Oil Shortage? This Economist Says Yes.

Its Green Shipping Initiative offer incentives such as reduced port fees for ships in return for using low-sulfur fuel.

CNN: Shipping looks to clean up its act

In some areas of Europe and the U.S., ships have been required by law for years to use low-sulfur fuel when in port.

CNN: Shipping looks to clean up its act