Heat-treatment of two heavy petroleum products containing vanadium and nickel

✍ Scribed by S. Bonnamy; A. Oberlin

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 867 KB
• Volume: 20
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(82)90086-0

✦ Synopsis

A raw coke very rich in vanadium (Z-3%) and an asphaltene with a high content in nickel were studied by means of a high resolution transmission electron microscope, a scanning transmission electron microscope equipped with X-ray energy dispersive analyser and by X-ray diffraction. Vanadium diffuses out from the raw-coke during heat-treatment and forms small crystals of VzO, trapped inside of carbon pores. After further heat-treatment vanadium carbide is formed which causes a catalytic transformation of the coke into a thermally stable partially graphitized carbon. In the asphaltene, nickel forms cubic crystals of metal at about 400°C. In both cases the metallic impurities are not uniformly distributed throughout the solid. All metallic matter becomes concentrated in a few particles. whereas most of the carbon is metal free. This appears to be common for samples of a low metallic content.