Abstract: Provided is an unleaded gasoline fuel which is substantially free of oxygenates, i.e., the fuel contains less than 1.0 weight percent oxygen based on the total weight of the fuel composition, and most preferably contains no oxygen containing compounds. The gasoline fuel of the present invention also has a Reid vapor pressure of less than 7.5 psi, a sulfur content of less than 30 ppmw, and more preferably less than 20 ppmw sulfur, and an aromatic hydrocarbon content greater than 30 volume percent and/or a 50% D-86 Distillation Point greater than 220° F. and/or a 90% D-86 Distillation Point greater than 330° F. The gasoline fuel preferably also has an olefin content of no greater than 8 volume percent, and more preferably 5 volume percent or less. It has been found that such a gasoline fuel offers a substantially oxygenate free gasoline which avoids the environmental impact of oxygenates, yet when combusted in an internal combustion automobile provides good performance and good emissions.

Abstract: Provided is an unleaded gasoline fuel which is substantially free of oxygenates, i.e., the fuel contains less than 1.0 weight percent oxygen based on the total weight of the fuel composition, and most preferably contains no oxygen containing compounds. The gasoline fuel of the present invention also has a Reid vapor pressure of less than 7.5 psi, a sulfur content of less than 30 ppmw, and more preferably less than 20 ppmw sulfur, and an aromatic hydrocarbon content greater than 30 volume percent and/or a 50% D-86 Distillation Point greater than 220.degree. F. and/or a 90% D-86 Distillation Point greater than 330.degree. F. The gasoline fuel preferably also has an olefin content of no greater than 8 volume percent, and more preferably 5 volume percent or less. It has been found that such a gasoline fuel offers a substantially oxygenate free gasoline which avoids the environmental impact of oxygenates, yet when combusted in an internal combustion automobile provides good performance and good emissions.

Abstract: Vinyltoluene is separated from close-boiling, olefinically unsaturated alkylaromatic compounds by extractive distillation. For example, vinyltoluene is separated from cis-.beta.-methylstyrene, and from .alpha.-methylstyrene by extractive distillation using .gamma.-butyrolactone as the extracting agent.

Abstract: The present invention provides a multistage process for the removal of tar, water and particulate contaminants from a hot product gas resulting from the in-situ gasification of an underground coal deposit, which comprises passing the hot product gas through a first heat exchange zone in indirect heat exchange relationship with a gasification gas to thereby sufficiently reduce the temperature of the product gas so as to separate the tar present in the product gas and provide a substantially tar-free product gas. Thereafter, the tar-free product gas is withdrawn from the first heat exchange zone and passed through at least one subsequent heat exchange zone in indirect or direct heat exchange relationship with a heat exchange material which has a lower temperature than the product gas. A major portion of the water originally present in the hot product gas is removed in the subsequent heat exchange zone.

Abstract: Indene is separated from close boiling, olefinically unsaturated alkylaromatic compounds by extractive distillation. For example, indene is separated from trans-.beta.-methylstyrene, and from 2-, 3- and 4-methylstyrene by extractive distillation using 1-methyl-2-pyrrolidone as the extracting agent.

Abstract: Provided is an unleaded gasoline fuel which is substantially free of oxygenates, and most preferably contains substantially zero oxygenates. The gasoline fuel also has a Reid vapor pressure less then 7.5 psi, a sulfur content less than 30 ppmw, an aromatic hydrocarbon content between 25 and 30 volume percent, and/or a 50% D-86 Distillation Temperature between 210 and 220° F., and/or a 90% D-86 Distillation Temperature between 300 and 330° F., and the fuel composition fails the California Predictive Model requirements for emissions. Preferably, the olefin content of the fuel is also 8 volume percent or less. Such a gasoline fuel offers a substantially oxygenate free gasoline which avoids the environmental impact of oxygenates, yet when combusted in an internal combustion automobile provides good performance and good emissions, despite failing the California Predictive Model. The gasoline fuel in particular can provide surprisingly lower NOx emissions than that predicted by the California Predictive Model.