Study On Thermodynamics And Kinetics Of Oxygen Carrier For CLAS

Oxygen plays a very important role in our daily life and industrial applications. Oxygen is the second largest volume chemical produced in the world, with an annual growth rate of about6%. Industrial applications in great demand for oxygen, however, the cost of oxygen production is still very high for existing oxygen production technology. The CLAS is based on the chemical-looping concept and is inherently simple and cost-effective. The specific power of the CLAS process just26%of an advanced cryogenic air-separation system. This method is suitable for most occasions with oxygen, has a very broad application prospects.CLAS is relying on the cyclic oxidation and reduction of a oxygen carrier as a means of separating oxygen from air. Oxygen carrier directly determines oxygen production system is good or bad. Selecting the appropriate oxygen carrier for Chemical-looping air separation is very important. The most important challenge for CLAS is the development of effective and robust metal oxide oxygen carriers. This paper selected some suitable oxygen carriers from thermodynamic properties, and to study their reactivity. Then established the deoxygenation kinetic mechanism model of oxygen carrier. The main contents are as follows:(1) Selected the appropriate metal oxides as the oxygen-carrying agent according to the physical and thermodynamic properties of metals from the periodic table. Then selected the appropriate inert carrier. Rusults showed that Cu-based, Co-based and Cu/Co-based oxygen carriers quite suited for CLAS.(2) The reactivity of oxygen carriers under different conditions were studied using the isothermal and non-isothermal thermogravimetry. The results showed that the reaction temperature of Oxygen carrier increases and the reaction time is shortened with increasing heating rate. The higher reaction temperature and the smaller particle diameter, the faster reaction rate for Oxygen carrier. Oxygen carriers have different reactivity with different inert carriers. The reaction activity is:CuO/ZrO2> CuO/TiO2> CuO/SiO2. (3) According to the experimental data obtained from STA409PC thermal analyzer, combined with FWO and Malek method, based on the popular gas-solid reaction mechanism functions to obtain the kinetic parameters of Cu-based, Co-based and Cu/Co-based oxygen carriers. Then established the kinetics mechanism models of reduction reaction of oxygen carriers and provided theoretical basis for industrial applications and further research.