Study On Plasma Electrolysis Degradation Of Biomass And Plastics

When the biomass is liquefied by the technology combining the plasma electrolysis with traditional biomass liquefaction technology,the solution resistance power and the plasma in the acidic electrolyte solution can efficiently heat the solution.Meanwhile,the active particles produced by the plasma and the H+ ions can quickly degrade biomass and plastics,providing a new method to crack high polymer macromolecules.In this paper,the heating mechanism and spectral characteristics of plasma electrolysis liquefaction of biomass were studied first,and then the waste polyethylene plastic was degraded by the plasma electrolysis.In the experiment of plasma electrolysis liquefaction of biomass,we chose polyethylene glycol 200 and glycerol as a mixed solvent,98%concentrated sulfuric acid as a catalyst,and pine wood chips as biomass to be tested under the power supply of DC pulse power.Through the single factor experiment,the optimal parameter of plasma electrolysis liquefaction of biomass was obtained while the liquefaction rate was maximum:biomass 5 g,polyethylene glycol 200 24 mL,glycerol 7 mL,and catalyst 250 uL.Then the change trend of the electrolyte solution resistance was measured while changing the solvent ratio,catalyst content,DC pulse power supply duty cycle and frequency.It is known that,as the reaction time increases,the solution res:istance decreases first and the solution temperature increases,corresponding to the degradation of the biomass macromolecule;as the reaction time continuously increases,the liquefaction rate of biomass and the solution temperature reach the maximum,and the solution resistance reaches minimum;as the reaction time increases again,the solution resistance begins to increase,and the solution temperature and the liquefaction rate keep highest,corresponding to the polymerization reaction,such as polycondensation,cyclization and so on.Through the trend of solution resistance change,we also obtained the optimal parameters of the power supply:DC pulse power supply amplitude 710 V,duty cycle 30%,frequency 200 Hz.Under the optimal parameters of the power supply and the optimal parameters of the electrolyte solution of liquefaction,the solution resistance can be as small as 500 ? at a reaction time of 150 s.In addition,through the measurement and the calculation of the resistance heating power and the output power of the power supply,it is found that the resistance heating power is dominant in the early stage and the discharge plasma power gradually increases while the solution temperature increased.The experiment result shows that the process of plasma electrolysis liquefaction of biomass is a synergistic process between solution resistance heating and plasma heating.Through the analysis of liquefaction products,it is known that biomass macromolecule including cellulose,hemicellulose,and lignin are decomposed into liquid products of high calorific value of 22.27MJ/kg including aldehydes,ketones,acids,esters and into some gases such as H2,CO,and CH4In the study of plasma electrolytic degradation of polyethylene waste plastics,we chose bubble film as the degradation material,liquid paraffin and octanol as mixed solvents,98%concentrated sulfuric acid and glycerol as mixed catalysts to carry out the degradation experiment under the power supply of DC pulse power.In the experiment,the bubble film interacts with the co-solvent to eventually produce three products:a waxy product,a liquid product,and a gaseous product.Adjustment of the solvent ratio and catalyst content to analyze the distribution of the three major products,we obtained the optimal reaction parameters:0.6 g of bubble membrane raw material,20 mL of liquid paraffin,7 mL of octanol,3 mL of glycerol,and 150 ?L of sulfuric acid.Under the optimal conditions,the mass of the wax yield can be almost completely lost by heating at a temperature of less than 300 ?.However,the mass of the bubble film material has no loss at a temperature exceeding 400 ?,it is sufficient to show that the bubble film is well degraded.Compared to the bubble film,the wax yield obtained by degradation has a larger number average molecular weight of 23143 and a larger weight average molecular weight of 102049.The amount of hydrogen in the liquid product obtained by degradation is significantly reduced,and the majority of the hydrogen in the solvent has been transferred to the wax production,which further indicates that the wax production is the result of the interaction of the bubble film and the solvent under the action of the plasma.In summary,the application of plasma electrolysis technology in acidic electrolyte solution can be used to crack polymer macromolecules,providing a new way to deal with discarded macromolecules material.