Gas evolution during oil shale pyrolysis. 1. Nonisothermal rate measurements

✍ Scribed by John H. Campbell; George J. Koskinas; G. Gallegos; M. Gregg

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 898 KB
• Volume: 59
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(80)90027-7

✦ Synopsis

The rate of evolution of CH4, CO, CO2, Hz, C2 hydrocarbons, and C3 hydrocarbons during pyrolysis of Colorado oil shale between 25 and 900°C is reported. All experiments were performed nonisothermally using linear heating rates varying from 0.5 to 4.0°C min-'.

Hydrogen is the major noncondensable gas produced by kerogen pyrolysis. The amount of H2 released is influenced, via the shift and Boudouard reactions, by the CO2 evolved from mineral carbonates. Lesser amounts of Cl, C2, and C3 hydrocarbons are produced. On the basis of heat content, however, the combined Cl to C3 hydrocarbons contribute twice as much as H2 to the heating value of the pyrolysis gas. The evolution of H2 and CH4 involves processes that are interpreted as a 'primary' pyrolysis of the kerogen to generate oil, and a higher temperature 'secondary' pyrolysis of the carbonaceous residue. The CO formed is a product of the Boudouard reaction; nearly complete conversion of the carbon residue to CO via this reaction is observed.