Carbon deposition characteristics of oil shale retorting gas

In order to further research the carbon deposition characteristics of oil shale retorting gas in the metal pipe, an experimental study on the carbon deposition characteristics of retorting gas was carried out under different conditions including temperatures (600, 650, 700, 750 ℃), reaction times (30, 60 min) and gas flow (10, 20 mL/min). A home-made continuous flow reactor system and a stainless steel tube reactor of 06Cr25Ni20 were used. The results show that the initial carbon deposition temperature range is 450-470 ℃. The carbon deposition morphology was analyzed through temperature programmed oxidation methods (TPO) and the scanning electron microscope. It shows that there are two different species of coke in the carbon deposition including amorphous carbon and filamentous coke. By means of EDS, 15.574% (mass fraction) of Chromium and 4.463%, 17.283% (mass fraction) of Nickel and Iron were detected and founded in coke layer stripped from tube inner surface, which proved that carburation of alloy. Meteorological chromatograph was used for analyzing the gas composition before and after different experiments. The results of the analysis show that the main material for carbon deposition is small molecule olefins. ©, 2014, Meitan Xuebao/Journal of the China Coal Society. All right reserved.