The evaluation of coal derived naphthas as gasoline-fueled automobile fuels by exhaust emissions.

In order to evaluate the feasibility of coal derived naphthas as gasoline-fueled automobile fuels, mass emissions of several substances in exhaust gas from a test automobile were measured by operating the automobile under 10 mode driving cycle and constant speed conditions at 20, 40 and 60km/h, three kinds of test fuels were prepared by mixing three kinds of coal derived naphtha and iso-octane for setting research octane for numbers at around 90. Two naphthas out of three were produced from Wandoan coal (sub-bituminous coal) by a solvent extraction liquefaction and Victoria coal (brown coal) by a direct coal liquefaction, and the rest was a hydrotreated oil of the latter naphtha.Mass emissions of carbon monoxide, hydrocarbons and nitrogen oxides from the test fuels containing 25 vol% of the coal derived naphtha from sub-bituminous coal and 28 vol% of the hydrotreated oil of the naphtha from brown coal were below permissible limits of 10 mode emission standard, but emissions of carbon monoxide and hydrocarbons from the test fuel containing 70 vol% of the naphtha from brown coal were over the permissible limits. These considerable increases resulted from the large content of naphtha, not the variation in the chemical or physical property.