1) Cracking 
(from the article `petroleum refining`) ...products. Catalytic reforming of naphtha replaced the earlier thermal reforming process and became the leading process for upgrading fuel ... One of the most far-reaching developments of the refining industry in the 1950s was the use of hydrogen, made possible in part by the availability of ......
[n] - the process whereby hydrocarbon molecules of petroleum are broken down into kerosene and gasolene by the addition of hydrogen under high pressure in the presence of a catalyst
the cracking of petroleum or the like in the presence of hydrogen.