The pyrolysis behavior of Huangling coal (HL) was investigated using KCl, CaO, and Fe2O3 as the catalysts. The catalytic pyrolysis characteristics of coal were studied by thermogravimetry, as well as from the yield of the pyrolysis products and gas and tar composition. The catalytic mechanism was discussed in terms of the changes in gas composition and kinetic analysis. The Doyle integral method was employed for investigating the reaction kinetics of the coal catalyst mixture. The general effect of the additive on the reactivity of coal pyrolysis was evaluated using the pyrolysis characteristic index P. The results show that KCl, CaO, and Fe2O3 exhibit a catalytic effect on the pyrolysis of HL. The char and gas yield increased with the addition of catalysts, and the tar yield first increased and then decreased. With the addition of 1.5% of KCl or Fe2O3 catalyst or 0.5% CaO, the best catalytic effect was observed for the pyrolysis of coal. Coal pyrolysis can be divided into two regions: 472–655 °C and 655–800 °C. With the addition of catalysts, the activation energy and pre-exponential factor decreased. Experiments were conducted using the three catalysts, and the pyrolysis characteristics of P were in the order of Fe2O3 > KCl > CaO.

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Removing CO2 from CH4/CO2 mixture gas is significantly important in natural gas upgrading and greenhouse gas emission control. In order to improve the separation effect, the influence of swing on removing CO2 from offshore natural gas by the adsorption was studied systematically by experiment and simulation. Firstly, the adsorption experiment was carried out under the quiescent condition, single direction swing with a frequency of 0.12Hz, bidirectional coupling swing with a frequency of 0.12 Hz and quiescent condition with a tilting angle of 20° by the swing experiment platform. The results indicated that the swing of the adsorber can reduce the adsorption purification effect, and which is not caused by the decrease of the adsorbent performance. Then, the adsorption purification model was established and the validity of the model was verified by experiments. Finally, the effects of tilting angle and L/D ratio of the porous zone, inlet flow rate of the mixture gas, particle diameter of adsorbent, and gas inlet distribution of the adsorber on adsorption purification under the quiescent and swing conditions were studied in detail. The results showed that decreasing the tilting angle of the porous zone and inlet flow rate of the mixture gas, or increasing the L/D ratio of the porous zone, the particle diameter of the adsorbent and the inlet amounts of the adsorber can reduce the adverse effect of swing on purification of natural gas. It is of great significance to improve the effect of adsorption purification of natural gas under swing condition by changing the adsorption conditions and structure of the adsorber. The research will provide a certain guidance for removing CO2 from offshore natural gas by adsorption.