Corn Stover Hydrolysate Hydrogenolysis To Low Carbon Glycols Over Ru/AC Catalyst

Low carbon glycols such as ethylene glycol and proplene glycol from fossil fuel were widely used in various fields as important chemical raw materials.Nowadays,the use of renewable biomass energy instead of fossil energy to produce low-carbon glycols has drawn extensive attention.Although the hydrogenolysis of sugar alcohols into low carbon glycols could achieve high yield,it has not yet been commercialized due to cost issues.In this work,we tried to prepare low carbon glycols from corn stover hydrolysate mainly containing glucose and xylose,which could reduce the cost.The effect of impurities in hydrolysate on hydrogenation process,the deactivation behavior of Ru/AC(Activated carbon)catalyst and the impurity removal have been extensively investigated.The results and conclusions are as follows:1.The impurities in the hydrolysate had different inhibitory effects on the hydrogenation process.The existence of lignin and cellulase significantly inhibited the hydrogenation process while 5-HMF and aromatic impurities showed obvious inhibitory effect only when the contents reached 0.6wt%.Furfural and inorganic salts did not influence the hydrogenation process.There was no obvious interaction between the impurities and the degree of inhibitory effect on hydrogenation process was positively correlated with the impurity content.2.Characterization results proved that the deactivation behavior of Ru/AC catalyst was mainly caused by the impurities deposition.Impurities such as lignin and cellulase would block channels in catalyst particles and cover the active sites,thus resulting catalyst deactivation.3.Activated carbon was used for impurity removal.It was found that acidic environment was conducive to the adsorption of impurities on activated carbon and the adsorption through continuous filtration showed better performance for impurity removal than that in a tank with magnetic stirring.The yield of low carbon glycols produced from the hydrolysate after removing impurity was enhanced,although it still could not meet the industry requirement and needs improving.