Show NATURAL GAS GASOLINE BLENDS by D B dow natural gas gasoline is made by collecting in the liquid state the condensable hydrocarbon vapors that ex exist in different natural gases in varying amounts in the richer type of natural gas the gasoline is generally recovered by compression and cooling if exceedingly high pressure or low temperature is used there is dissolved in the gasoline a large amount of very volatile material which evaporates rapidly at atmospheric ten temperature and pressure in the leaner type of natural gas the gasoline vapors are selectively absorbed from the perin permanent anent gases by passing the natural gas through an absorbing oil the gasoline is recovered by distilling the saturated oil and as compared with compression gasoline is of high baume gravity and low vapor pressure before a volatile gasoline can be transported in tank cars it is necessary to decrease its volatility in order to lessen the risk of fire or explosion as well as to prevent excessive evaporation eva portion in transit this can be accomplished either by weathering the gasoline or by blending it with a more stable material naptha being commonly used in the weathering process the more volatile portions of the gasoline are allowed to evaporate and the losses in volume are very large therefore blending is preferable wherever possible it is very difficult however to produce by blending in gasoline plants a motor fuel which is equal to straight t run refinery gasoline in order to make a blended motor fuel of a grade equal to straight craight b run gasoline only a small percentage of natural gas gasoline can he be blended with the naptha consequently it is customary to blend the gasoline with only enough naphtha to enable it to be shipped to an oil refinery when the material is again blended to form a finished motor fuel the addition of natural gas gasoline to straight run products is often necessary first to balance the large b amount of high boiling material included in the gasoline fraction in modern refineries and second to supply the deficiency of low boiling material in certain brudes in the past blends were frequently made with kerosene and were subsequently distilled the kerosene merely acting as a carrying agent for the natural gas gasoline however this running rerunning re was found to be rather expensive on oil account of distillation losses tue due to the volatility of the natural gas gaso line this particular type of blend was also tried as a motor fuel but proved to be very unsatisfactory the most common blending material now used in the mid continent field is a naphtha ranging in gravity from 50 to with an end point of F or less when this naphtha is blended with natural gas gasoline the vapor pressure and baume gravity of the blend is much lower than in the raw gasoline and there is not enough high boiling material to injure the resultant motor fuel when this blend is added in small amounts to straight run gasoline it is not necessary to use 50 52 naphtha for blending with natural gas gasoline as there are other comparatively volatile petroleum distillates that will accomplish the same purpose it is quite possible to use straight run gasoline of 56 58 B gravity as a blending material when the object of blending is that of bringing down the vapor pressure to conform with shipping regulations it has been found that blends made with either 50 B naphtha or 56 B gasoline blended in the same proportion with natural gas gasoline c ra soline will give almost identical vapor pressures this possibility can be made use of to advantage when 50 B naphtha commands a high petrol pupi chemist bureau of mines er price than 56 B gasoline or when naphtha is temporarily unobtainable the bureau of mines has found that by rerunning kerosene in the bartlesville Bart lesville experimental refinery 20 2070 of 46 B naphtha with an end point of F could be obtained the present price of kerosene is so low that many drefin ers are mixing the unfinished material with fuel oil and gas oil instead of refining it an opportunity therefore exists for the running rerunning re of kerosene distillate and obtaining a naphtha with an end point of F it should be pointed out however that to get yields comparable to those obtained by the bureau efficient fractionating fractionation towers must be used the naphtha produced in in this way is an excellent blending in material and will reduce the vapor pressure of the gasoline to the same extent as 50 B naphtha it would not however however produce a blend which is suitable for motor fuel when used alone as the mixture would contain an excess of both low boiling and high boiling fractions and would be deficient in the hydrocarbons that have medium boiling points this blend can however be advantageously added to straight run gasoline since the natural gas gasoline contained in it will vill furnish the required low boiling bo ailing material |