Coal coprocessing with waste petroleum materials achieves the dual purpose of upgrading both the coal and the waste materials economically. The kinetics of coal coprocessing with petroleum waste has been studied experimentally and modeled mathematically. A combined parallel and series reaction scheme was assumed for the coal liquefaction. Experiments were carried out in a tubing bomb microreactor at temperatures of 375 to 425 degrees C, at reaction times of 15-120 min, with 10% coal loading and with 1250 psig pressure. Coal conversions as high as 98% were obtained during coprocessing. More than 70% conversion to oil is achieved at high temperatures and grease loadings. The effect of temperature and grease loading on coal liquefaction were also studied. A rigorous parameter estimation technique was employed to determine the parameters involved in the model. The model predictions are good for experimental conditions other than those used to determine the model parameters. Higher conversion and higher rate of liquefaction obtained during coprocessing were explained from the obtained kinetic rate parameter values.