Experimental Study On Microwave-assisted Bagasse Pyrolysis And Gasification

This paper focuses on the pyrolysis characteristics of bagasse in a microwave digestion furnace and a tube atmosphere furnace,comparing the product characteristics of microwave pyrolysis with those of conventional pyrolysis.The main objective is to improve the quality of the gas product of bagasse microwave cracking,therefore varying different working conditions,changing the gasification agent and examining the effect of home-made Ni/SiC catalyst on the microwave cracking characteristics of bagasse.The paper firstly compares the differences between microwave heating methods and conventional heating methods.Microwave heating is able to create high temperatures in a short period of time,which can promote secondary cracking of tar,and the gas product yield is significantly higher than conventional pyrolysis at the same temperature.The pyrolysis characteristics of the three components of biomass were then studied at 500℃ to 900℃.Lignin showed good carbonisation characteristics,with solid product yields of up to 51.87 wt.%pyrolysed at 500℃.With gas as the target product,cellulose and hemicellulose showed good gasification,with yields of 62.88 wt.%and 61.51 wt.%for cellulose and hemicellulose,respectively,at 900℃.Compared to conventional pyrolysis,microwave pyrolysis gas products have more H2 and CO and less CO2 and CH4,so microwave pyrolysis gas products have higher quality and are more conducive to biomass gasification.In the microwave digestion furnace,the effects of power,catalyst dosage,Ni loading and acid-base pretreatment on pyrolysis products were investigated.It is found that the increase of power and catalyst dosage will promote the secondary cracking of tar and the increase of hydrogen yield under the economic conditions.Acid treatment contributes to the production of CO and CO2 and the improvement of the quality of liquid products.Alkali treatment contributes to the fracture of lignin CO and O-H.After KOH treatment,the hydrogen yield reaches 38.13 g/kg biomass.The comparison of CO2 and water vapor as gasification agent shows that CO2 gasification agent can promote the forward progress of Boudouard reaction and provide more CO for gas products.Water vapor can increase the hydrogen element for bagasse and also increase the microwave absorber of bagasse.The effect of water vapor is better than CO2 gasification agent in hydrogen production.After adding selfmade 8 wt.%Ni/SiC catalyst,when the steam inlet rate is 0.5ml/min,the hydrogen yield is as high as 100.93 g/kg biomass,and the potential hydrogen yield is as high as 116.65 g/kg biomass.