Study On Rapid Pyrolysis Of Sludge By Mechanochemical Prepared Under Different Conditions

Energy and environmental issues had gradually become the key issues that restricted the progress and development of human society.The development of clean and efficient new energy had become a research hotspot in countries around the world.As a biomass resource,sludge contained a large amount of organic matter that could be recycled and used.For example,bio-fermentation,pyrolysis and gasification could be used to produce high-value,clean and pollution-free hydrogen energy.Among them sludge was carried out by pyrolysis for hydrogen-rich gas production had the advantages of strong operability,short reaction time and thorough disposal.In this paper,the pyrolysis of sludge was studied using a combination of mechanochemical pretreatment and fixed bed pyrolysis.By analyzing the distribution characteristics of the sludge pyrolysis products under different catalysts,different temperatures and different moisture contents,and the FT-IR spectrometer,specific surface area analyzer,integrated thermal analyzer,and X-ray diffractometer were used to characterize the solidification of sludge and pyrolysis coke,exploring the mechanism of sludge pyrolysis gas,coke and tar.The following main conclusions were drawn:?1?The choice of adding catalyst CaO mixture could obviously improve the quality of pyrolysis gas,and make the maximum value of the pyrolysis gas mass,the pyrolysis gas yield of the sludge,the low calorific value of the unit mass sludge and the yield of H₂,respectively,32.1%,0.441m³·kg^-1,68.644kJ·kg^-11 and 7.377mol·Kg^-1,respectively.The number of characteristic absorption peaks in the FTIR spectra of pyrolysis coke added to different catalyst mixtures was small and the intensity was low,and the organics had been fully decomposed;The addition of catalysts CaO and CaO-coke to the sludge increased the rate of weight loss in the third stage of the thermal weight,and the former enhanced the kinetic energy and apparent activation energy of organic molecules?13.39-70.43 kJ·moL-1?,thereby promoting the pyrolysis reaction.?2?With the increase of temperature,the pyrolysis gas production quality of the mixture was improved,the pyrolysis coke mass fraction showed a downward trend,and the pyrolysis tar mass fraction increased significantly at 800°C,while at other temperatures,the mass fraction was based on 40%fluctuations;A large amount of calcite was generated in the pyrolysis reaction,and inhibiting the pyrolysis coke adsorption and pore structure development of the mixture.?3?Appropriate moisture contents was beneficial to improve gas production results.When the moisture contents of the mixture was 45%,the pyrolysis of free and dehydroxylation of the associative and hydroxyl groups produced H₂O to increase the quality of the pyrolysis gas,especially the pyrolysis gases.H₂ mass fraction reached the maximum value of 45.1%.The vitreous bulge was not detected in the ball milled and pyrolyzed minerals under different moisture contents,and the overall crystallinity of the mixture was good.