WASHINGTON (CN) – “Knock, knock.” “Who’s there?” “Benzene reduction.” Benzene alkylation is added to the Environmental Protection Agency’s list of approved technologies oil refineries may use to collect early credits when they produce gasoline with an annual average benzene content of 0.62 percent.
One percent benzene has been permitted, but since benzene is known to be toxic the percentage allowed in gasoline is being reduced by 2011. Last year’s rule requiring the drop by 2011 skipped alkylation because it was thought to be less cost effective than other methods. The same new rule also includes the process by which a control technology or operational change not listed in the EPA rule may be considered for early credits. Once the actual amount of benzene in a refinery’s gasoline drops to 1.3 percent, credits may be used to bring it down further. Benzene is added to gasoline to keep it from igniting in a car engine more often than when the spark plug sparks, causing the engine to “knock” from the extra explosions. Click here for details and other new rules and notices.