The increasing demand needed for World War 2 aided the development of petroleum refinery processes. The changes were brought about by the demand for higher grade fuels and the transitions and developments in the combustion engines. Environmental regulations also played a role in the innovations of petroleum refining. The introduction of the new processes encompassed the refinery processes that we know as separation, conversion, finishing, and support.

From this world war, thermal cracking refineries were needed for quicker and easier production of petroleum based products. This war brought together a sort of alliance for a combined effort of petroleum refining for more powerful fuels. The new developments brought about by this alliance was able to increase the yield as well as produce a multitude of products. It also aided the finishing processes for stabilizing and purifying the products of thermal cracking. Boosting the octane numbers of the petroleum fuel allowed for more power for the machinery needed for not only war but also for automobiles which were becoming an increasingly demanding notion. There was still a need for kerosene at this time as well because of the slow electrification outside the urban areas. The high demand of the light and medium distillates made this an important task to experiment and develop new ideas of petroleum refining.