Question

does non - sooty flame give high temperature

Answer 1

Yes for sure! By saying non -sooty flame you mean the the flame which burns with blue colour. In fact the highest temperature from burning a certain object can be obtained from a non-sooty flame. The most common example is the fire in the gas stove.
A non-sooty flame can be obtained by supplying enough oxygen and this type of flame does not leave black deposits and utilises the fuel completely