Font Size: a A A

Study On The Synergy In Co-combustion Of Oil Shale Semi-coke With Torrefied Cornstalk

Posted on:2018-09-27Degree:MasterType:Thesis
Country:ChinaCandidate:W X LiangFull Text:PDF
GTID:2322330512481623Subject:Power engineering
Abstract/Summary:PDF Full Text Request
Oil shale semi-coke is a hazardous waste product formed during thermal processing of the oil shale,which dispensing is difficult.This is actually an environmental concern because the retorting waste contains toxic environmental compounds.Combustion experiments with oil shale semi-coke from Huadian retorts,torrefied cornstalk as well as their blends were conducted using a thermogravimetric analyzer under air atmosphere in this paper.Based on the previous research,TG-FTIR and tube furnace were used to study the influence of mixing ratio and heating rate,and the parameters of co-firing were obtained.The kinetic parameters of the samples were calculated and the activation energy of the mixed samples was obtained to determine the co-firing mechanism.The interaction index MR and the average activation energy were used to analyze the synergy of the co-firing process.The mixed sample was predicted in a circulating fluidized bed by the AKTS software.The gas release characteristics of the combustion process were analyzed by FTIR data.The co-firing characteristics of oil shale semi-coke and torrefied cornstalk were studied by TG-FTIR in terms of mixing ratio and heating rate.Three main stages were distinguished during the co-firing process of the samples.With the heating rate increasing,each peak widened and deepened while shifting towards higher temperature values.With the increase of the torreficated cornstalk content,the sample mass loss in the first stage increases and combustible indexes,the devolatilization index and the general combustion parameter increases,this indicates that the combustion characteristics of oil shale semi-coke improved.Combustion kinetic parameters were calculated by the method of Friedman equation and Vyazovkin equation.The results show that the two results show the same rule,to ensure the accuracy of activation energy.The calculated average activation energy curve is always greater than the average activation energy experimental curve,which indicates that synergy existed in the co-firing process.The interaction index MR was used to analyze the synergy of the co-firing process.The results showed that the main process occurring in the combustion of the fixed carbon.The reaction progress in a CFB can be predicted using the AKTS-Thermokinetics Software and the shortest burnout time was estimated.Based on the synergistic effect in the co-firing process and AKTS prediction,the gas release characteristics of the mixed samples were analyzed.The main combustion gases is CO2,along with a small amount of CO,SO2,NO and NO2.According to the gas release characteristics under the mixing ratio,the optimal proportion in the circulating fluidized bed combustion condition is selected,which will provide important theoretical basis for future engineering application.
Keywords/Search Tags:Oil shale semi-coke, Torrefied cornstalk, Synergy, Kinetic analysis, Prediction of Circulating Fluidized Bed Combustion
PDF Full Text Request
Related items