Renewable Oxygenate Blending Effects on Gasoline Properties
Renewable Oxygenate Blending Effects on Gasoline Properties
复制标题
DOI：
10.1021/ef2010089
复制
发表时间：
2011-10-01
期刊：
影响因子：
5.3
通讯作者：
McCormick, Robert L.
中科院分区：
文献类型：
--
作者：
Christensen, Earl;Yanowitz, Janet;McCormick, Robert L.
将含氧物乙醇、正丙醇、异丙醇、正丁醇、正丁醇、2-甲基-1-丙醇(异丁醇)、1-戊醇、3-甲基-1-丁醇(异戊醇)、乙酰丙酸甲酯、乙酰丙酸乙酯、乙酰丙酸丁酯、2-甲基四氢呋喃(MTHF)、2-甲基呋喃(MF)和2，5-二甲基呋喃(DMF)混合在3种混合汽油中，用于含氧量为3.7wt%的混合汽油调合(BOBS)。将共混物的化学和物理性能与ASTM规范D4814对火花点火发动机燃料的要求进行了比较，以确定其作为汽油填充剂的用途。测量了蒸汽压、汽锁保护、蒸馏、密度、辛烷值、粘度和萃取到水中的潜力。乙醇在3.7%氧气中混合，如预期的那样，蒸汽压增加了5-7千帕。2-丙醇略微提高了挥发度最低的BOB的蒸气压，而所有其他含氧物使蒸气压降低了高达10千帕。威尔逊方程的系数与测量的蒸汽压数据进行了拟合，结果表明，该方程可以很好地预测含氧汽油在不同汽油中对5种单醇和MTHF的蒸气压。高级醇和其他含氧物通常可以改善气阻保护。在2.7%氧气中混合的乙酰丙酸丁酯导致蒸馏终点超过225摄氏度，因此不符合规范。蒸馏参数在测试的其他含氧物的规格范围内。除乙醇、MF和DMF外，当混合到为乙醇混合而设计的低辛烷值混合料中时，所考察的含氧物将不会在这些混合水平上产生令人满意的辛烷值的混合。然而，除1-戊醇和MTHF外，所有被测试的含氧物都产生了辛烷值的增加。对于乙醇、丙醇异构体和乙酰丙酸甲酯，在室温耐水性实验中，20wt%或更多的含氧物可以被提取到水中。丁醇异构体和乙酰丙酸乙酯的萃取率在4%~8%之间。其他含氧物的萃取率为2%或更低。在低于0摄氏度的温度下，乙酰丙酸甲酯以单独的液体相从汽油中分离出来。
The oxygenates ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol (isobutanol), 1-pentanol, 3-methyl-1-butanol (isopentanol), methyl levulinate, ethyl levulinate, butyl levulinate, 2-methyltetrahydrofuran (MTHF), 2-methylfuran (MF), and 2,5-dimethylfuran (DMF) were blended in three gasoline blendstocks for oxygenate blending (BOBs) at levels up to 3.7 wt % oxygen. Chemical and physical properties of the blends were compared to the requirements of ASTM specification D4814 for spark-ignited engine fuels to determine their utility as gasoline extenders. Vapor pressure, vapor lock protection, distillation, density, octane rating, viscosity, and potential for extraction into water were measured. Blending of ethanol at 3.7% oxygen increased vapor pressure by 5-7 kPa as expected. 2-Propanol slightly increased vapor pressure in the lowest-volatility BOB, while all other oxygenates caused a reduction in vapor pressure of up to 10 kPa. Coefficients for the Wilson equation were fitted to the measured vapor pressure data and were shown to adequately predict the vapor pressure of oxygenate gasoline blends for five individual alcohols and MTHF in different gasolines. Higher alcohols and other oxygenates generally improved vapor lock protection. Butyl levulinate blended at 2.7% oxygen caused the distillation end point to exceed 225 degrees C, thus failing the specification. Distillation parameters were within specification limits for the other oxygenates tested. Other than ethanol, MF, and DMF, the oxygenates examined will not produce blends with satisfactory octane ratings at these blend levels when blended into lower-octane blendstocks designed for ethanol blending. However, all oxygenates tested except 1-pentanol and MTHF produced an increase in octane rating. For ethanol, the propanol isomers, and methyl levulinate, 20 wt % or more of the oxygenate could be extracted into water in a room-temperature water tolerance experiment. For the butanol isomers and ethyl levulinate, the percent extracted ranged from about 4% to 8%. Extraction for other oxygenates was 2% or lower. Methyl levulinate separates from gasoline as a separate liquid phase at temperatures below 0 degrees C.