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In this work, pyrolysis experiments were conducted on Indonesia oil sands in a Cracking device at different pyrolysis temperatures. The effects of pyrolysis temperature on total hydrocarbon yield, liquid hydrocarbon production rate and gas production rate were investigated. Below 300 °C, the pyrolysis products were mainly gaseous. However, the proportions of liquid and gas products were identical above the temperature of 300 °C. The relationship between the volume fraction of gaseous products and temperature was analyzed using gas chromatography. The presence of functional groups of methyl, methylene, aldehyde, ketone, acid, fat, alkene and aromatic hydrocarbons in liquid pyrolysis products was investigated at different pyrolysis temperatures. The pore structure, electron microscope and fractal dimension of the chars were also analyzed. The result showed that the amount of adsorbed nitrogen reached the maximum value at 450 °C. The adsorption loop of char was close to the B-type loop, and the pore was mainly the slit hole. In addition, the pore structure was very well developed. The BET specific surface area and pore volume presented their peak values at 450 °C and the fractal dimension was obtained using FHH equation, which peaked at the temperature of 450 °C. The pore structure was loose and there was no obvious connection between the particles. Finally, the overall fractal value was slightly lower than the nitrogen adsorption fractal value.

TGA/DSC1 thermogravimetric analyzer and Fourier infrared spectrometric analyzer (FTIR) were used to conduct a series of combustion experiments using oil shale semi-coke, corn straw, and blends of the two. The results showed that the volatile initial precipitation temperature and ignition temperature of mixed samples are much lower than oil shale semi-coke, but it slightly higher than corn straw. The volatile initial precipitation temperature and ignition temperature of the mixed sample are increased with the increase in heating rate. When the heating rate is constant, the combustion process presents the trend to the low temperature; the peak value of the low-temperature section is high and intense release of volatile, thus improved combustion characteristics of the mixtures. Infrared spectral results are that: with increasing proportion of corn straw, A CO/ $$A_{\text{CO}_2}$$ decreases gradually; the utilization rate of mixtures is improved. The value of A CO/ $$A_{\text{CO}_2}$$ is minimum at the heating rate of 20 K min−1, combustion effect of mixtures is best, and the burnout rate is highest. RMS and MR values are used to evaluate the mutual influence of the co-combustion process and the study showed that main effects of the interaction occurred in second, third and fourth stages, the second and third stages are the favorable effects, and the fourth stage is the adverse effect and when the mass ratio of the semi-coke and the corn straw is 7:3, the mutual influence is the largest and the beneficial effects. The model of distributed activation energy is applied to analyze co-combustion kinetics of the blends. The results show that activation energy presents a rising tendency during the impelling of reaction, which is unanimous to the change law of DTG and FTIR curves. The results can provide reference for efficient combustion of oil shale semi-coke and corn straw.