Bitumenous paints from refinery sludge

This paper reports the data obtained on an attempt at the utilisation of th e oily sludge, which is a dumped waste of petroleum refineries. Growing pub lic concern over the health and environmental implications of these wastes has forced the regulatory agencies to make it mandatory for these industrie s to undertake the disposal of these wastes in an effective and environment ally safe manner. In the present work, the above sludge after purification was subjected to vacuum distillation to recover approximately 17% of lighte r oils. The residue was subjected to heat treatment at 225 degreesC for 2.5 h with '2.5% w/w AlCl3' to obtain industrial bitumen 90/15 grade (Industri al bitumen are of different types depending on the softening point-penetrat ion relationship. The first figure 90 represents the softening point while the second figure 15, represents the penetration. Both penetration and soft ening points are a measure of consistency for bitumen). The usefulness of t he above industrial bitumen was tried in the preparation of bituminous pain ts. All three formulations investigated were found to be homogeneous showin g no separation of solvent. There was no coagulation of the asphalt base no r settling or packing in the container. These samples were found to meet th e requirements of drying time, consistency, finish, stripping, flexibility and adhesion, keeping properties, etc. It was also seen that the heat resis tance of these bituminous paints can be increased considerably by including cashew nut shell liquid-formaldehyde resin in the formulation. Cashew nut shell liquid (CNSL) is a cheap by-product of the cashew industry, and its u tilisation can also help to reduce production costs of bituminous paints. T his study also showed that incorporation of chlorinated rubber in the formu lation would enhance the acid resistance considerably without affecting hea t resistance and other desirable properties. This method of using sludge as bituminous paints can be a simple, eco-friendly and useful means of dispos al in petroleum refining industries. (C) 2001 Elsevier Science B.V. All rig hts reserved.