| Since the 21 st century,the depletion of fossil fuels,environmental pollution and global warming have made it necessary for us to greatly increase the use of renewable energy.At present,China is gradually reducing coal consumption to improve environmental quality,and biomass solid molding fuel is one of the most widely used biofuels in the Chinese market.However,due to the lack of research on its quality,the existing biomass solid molding fuel quality evaluation system is complex and time-consuming,requires very expensive equipment and trained analysts,and lacks efficient testing methods.it has seriously restricted the development of biomass molded fuel industry in China.Therefore,it is necessary to study the test methods of solid biomass fuel characteristics and establish relevant standards to lay the foundation for the utilization of biomass solid molding fuel.In this study,taking straw biomass solid molding fuel as the research object,through 35 test data of straw biomass solid molding fuel,the qualitative relationship between moisture,ash,volatile and fixed carbon content and low calorific value,high calorific value and carbon content in industrial analysis and Pearson correlation were analyzed,and based on the correlation between the known physicochemical properties of fuel,the qualitative relationship between moisture,ash,volatile,fixed carbon content and low calorific value,high calorific value and carbon content and Pearson correlation were analyzed.Taking the four indexes of industrial analysis(moisture,ash,volatile and fixed carbon)as independent variables,using 35 groups of experimental data as training set,three sets of mathematical correlations about high calorific value,low calorific value and carbon content are derived,and then the model is tested based on 7 groups of experimental data.Finally,on the basis of the model,the necessary detection equipment and technology for the large-scale application of biomass solid fuel in China are established.The research results are as follows:(1)The low and high calorific values of biomass solid fuel are directly proportional to the content of volatile matter,and negatively related to the content of ash.The content of carbon in air-dried base is proportional to the content of volatile matter and negatively related to the content of ash.Overall,the calorific value and carbon content of biomass solid fuel are greatly affected by its volatile matter and ash composition.(2)The multivariate linear regression prediction model was established by multivariate linear regression(MLR)method.The internal and external tests show that the three models have ideal prediction ability,and the error range is significantly reduced.The R2 and R2 prep values of the high calorific value prediction model are 0.900 and 0.730 respectively.Compared with the existing research results,the range of relative residue is reduced to-2.59%-2.26%,which can provide a strong basis for the calorific value and carbon element analysis of industrial biomass solid fuel.finally,the application domain of the model is defined by Williams diagram.(3)The traditional hammer crusher is modified to make it more suitable for the crushing of biomass raw materials.(4)Compared with the published national standard for the determination of calorific value of biomass solid fuel,the detection conditions of biomass solid molding fuel were optimized by orthogonal experiment,and the disposal measures of acid waste liquid produced by the experiment were put forward.In this study,a set of convenient and fast calculation methods and techniques are established,which can be used to quickly detect the calorific value and carbon content of industrial biomass solid fuel,and to improve the sample preparation equipment and calorific value determination method of biomass solid fuel.it provides a theoretical basis for the full and efficient use of biomass energy. |
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