Pilot experiment of oily cuttings thermal desorption and heating characteristics study

Thermal desorption disposal of oily drilling cuttings was tested on the developed medium sized experimental system. The thermal desorption unit adopted electromagnetic induction heating during continuous conveying of materials by double screws, and the handling capability was 250 L/h. Thermal desorption test at different temperatures (300–550 °C) were carried out in conditions of residence times of 7 min and 12 min respectively. Total petroleum hydrocarbon (TPH) content of samples after treatment reduced to less than 1% when heating temperature up to 450 °C, and the oil removal rate was about 95%. The residual content of TPH dropped to 0.3% when heating temperature at 550 °C and residence time reached to 12 min. The temperature distribution of the material in heating bed obtained by numerical simulation based on test operating conditions. A temperature rising lag area of materials in filling section of barrel was found when heating. The material temperature in this area was only about 55–65% of the setting value when residence time reach to 12 min, while the other areas temperatures could up to above 90%, and the deviation between the material temperature and the setting value became obvious when the temperature is higher.