Laser pyrolysis of carbonaceous rocks

Flash pyrolysis on carbonaceous rocks is used to determine total carbon contents as well as the state of thermal maturation of specific samples. Short, intense heating greatly accelerates maturation-like processes. A series of radical fragments are generated leaving complex char residue. These volatile fragments quench into stable molecular species, influenced by the pyrolysis environment.Experiments are described that utilize pulsed laser heating on rock samples. This convenient technique requires minimum sample preparation and is readily automated. Intense laser pulses (2–10 J) generate an acetylene-rich plasma that interacts with the normally short-lived radical fragments. During the rapid quenching process, acetylene-tagged stable compounds are formed as a direct result of acetylene-radical combination processes. Analysis of these acetylenic derivatives by gas chromatography—mass spectrometry gives a unique interpretation of both the sediment and the maturation process.