ABSTRACT
For many years, crude oil has been the cheapest source of liquid fuels in many countries. The balancing between product yield and market demand without manufacturing large quantities of low-commercial-value fractions has long required processes for the conversion of hydrocarbons of one molecular weight range and/or structure into another molecular weight and/or structure. Basic processes for this are the so-called “cracking” processes in which relatively heavy hydrocarbons are broken down (i.e. cracked) into smaller, lower-boiling fractions. In the present market, there is increasingly less high quality crude oil but more bitumen with a very high content of asphaltenes. This is why one has to realize that heavy bitumen and/or vacuum residues from petroleum refineries have value as an alternative feed for the production of liquid fuels. In Canada, for example, 60% of all crude oil sources are in the form of bitumen (tar) sands [1]. But by using almost all the existing cracking processes, coke formation is inevitable. This makes all these processes non-economic; i.e., the present thermal treatment processes cannot completely solve the problem of production of fuel fractions from heavy residues of crude oils.
