Study On Co-gasification Characteristics Of Gas Coal In Fuyang And Wheat Straw

Co-gasification of biomass and coal can realize efficient and clean utilization of biomass fuel,make up for the deficiency of biomass gasification alone,and improve energy utilization efficiency.In this paper,gas coal and wheat straw in suburban xuzhou were taken as research objects.Pyrolysis experiment,non-isothermal gasification experiment and semi-coke isothermal gasification experiment were carried out on raw materials of gas coal and wheat straw on a synchronous thermal analyzer in CO₂,and the kinetic model of gasification reaction was established.Gasification characteristics of gasifier coal semi-coke and mixed semi-coke were studied in a?37?60 mm tubular gasifier in CO₂.It mainly includes the following aspects:?1?The pyrolysis experiment of wheat straw and gas coal was carried out on the synchronous thermal analyzer.The pyrolysis of raw materials showed that the pyrolysis activity of wheat straw was higher than that of gas coal.The effects of three heating rates on the pyrolysis of raw materials were investigated,and the results showed that the heating rate had the same trend with the weight loss curve of the pyrolysis of raw materials.At the same heating rate,the increase of wheat straw mixing ratio increases the devolatilization weight loss rate during the co-pyrolysis of raw materials,and the temperature corresponding to the peak value of maximum weight loss decreases.The results show that the synergistic effect of co-pyrolysis of gas coal and wheat straw is not obvious.?2?On the synchronization of thermal analyzer of wheat straw and non-isothermal gas coal for gasification experiment in CO₂,the effect of heating rate on raw material gasification was investigated,the results show that the increase of heating rate start gasification temperature rise correspondingly,coalite gasification stage of rate increases obviously,thermal weightlessness of wider temperature region,the gasification reaction time shortened.Under the same heating rate,the influence of the increase of wheat straw blending ratio on the co-gasification of mixed samples was studied,and the results showed that the mixing ratio played a great role in promoting the gasification of gas coal.TG and DTG curves were made based on the theoretical and experimental values of weightlessness changes of mixed samples,and obvious synergistic effects were explored in the co-gasification process.For gasification process,the fitting correlation coefficient is higher by using the reduced core model?SCM?.As the gasification temperature increases,the reaction activation energy E and preexponential factor A increase correspondingly.?3?Isothermal gasification experiment of semi-coke was carried out on the synchronous thermal analyzer in CO₂,and the influence of gasification temperature and wheat straw blending ratio on the carbon conversion rate and reactivity of semi-coke was studied.The results showed that the increase of gasification temperature and blending ratio increased the carbon conversion rate and reactivity index.The kinetic homogeneous model?HM?and the reduced core model?SCM?were established,which showed that HM model fitted well at high temperature?1000 ^oC?and SCM model fitted well at low temperature?900 ^oC?.?4?Gasification experiment in CO₂ was carried out on the semi-coke in a?37?60mm tubular furnace to explore the influence of gasification temperature and the mixing ratio of wheat straw on the gas component,gas calorific value,effective gas?H₂+CO?component and hydrogen carbon ratio?H₂/CO?produced by mixing semi-coke.The results showed that the increase of gasification temperature and the increase of wheat straw mixture ratio resulted in the increase of CO content in gas components,the decrease of CO₂ content,the change of CH₄ and H₂ was not obvious,the increase of gas calorific value and the decrease of H₂/CO.