185Refining Processes for Used Oil Recycling to Base Oils or Fuels
The hot, ltered oil can be withdrawn as an intermediate product which is suitable
for various industrial applications, or it can be preferably taken to a hydrogenation
process. In this case, it is mixed with hydrogen, heated to a temperature between
200°C and 480°C (390°F and 895°F), and the sulfonates react as in the rst embodi-
ment of the patent process. The fourth contactor contains, preferably, bauxite or an
activated carbon adsorbent bed, but other adsorbents are also considered. The adsor-
bent causes the ammonium salts of sulfonic acids and the ashless detergents in the
oil to break down and decompose. It also binds some of the resulting products and
prevents them from ...