All compositions in this question are by mass. 75% of a straight-run refinery gasoline stream is mixed with 15 te/h of a 60:40 mixture of pentane and hexane to produce a blended gasoline with an improved octane rating. The composition of the straight-run stream is: butane (C4) 5%, pentane (C5) 10%, hexane (C6) 25%, heptane (C7) 60%. The blended gasoline contains 20% pentane. Calculate :

a) the flow rate of the straight-run gasoline stream which is not blended (i.e. stream 4) Answer te/h

b) the composition of the blended gasoline in mass % for: butane %, pentane %, hexane %, heptane %