HPLC Analysis Of Water-soluble Products From Hydrothermal Liquefaction Of Bagasse

Biomass is known as a kind of rich and renewable energy with advantages of clean and low cost.The products of biomass hydrothermal liquefaction include oil-phase products and hydrophilic products.Hydrophilic products refer to the byproduct of the generation of biomass oil,and consist of many chemical components that can be used as important raw materials.The utilization efficiency of biomass hydrothermal liquefaction products can be greatly enhanced by development and employment of those chemicals.High performance liquid chromatography(HPLC)has been widely used in recent years as an effective technique to determine the hydrophilic products,thus for we employed the HPLC to analyze the hydrophilic products.The research contents and conclusions are as follows:As the raw material,bagasse was treated in a hydrothermental reactor with high pressure and elevated temperature,and subsequently the hydrophilic products were investigated.The present study optimized the HPLC methods for the determination of furfurals,saccharides,acids and phenols products,investigated the influence of factors(chromatographic column,mobile phase,detector,detection wavelength,column temperature,flow rate,etc)on the separation of desired products,and determined the HPLC analytical conditions.When separated and determined the sugars,the differential refraction detector and Inert Sustain NH2 amino column were used,mobile phases were acetonitrile and water with volume to volume ratio equal to 80: 20,detector and column temperature were 30 ?;When separated and determined the phenols and furfurals,the photodiode array detector and C18 column were used,wavelength was 280 nm,mobile phases were methanol and aqueous solution with acetic acid(1%)gradient eluting,detector and column temperature were 40 ?;When separated and detected the acids,the photodiode array detector and C18 columns were used,detection wavelength was 210 nm,mobile phases were methanol and buffered salt solution with potassium dihydrogen phosphate(0.02 mol/L)gradient eluting,detector and column temperature were 30 ?.The results showed that the hydrophilic products were complex,the sugars consisted of glucose,fructose,xylose,arabinose,cellobiose and sucrose;the furfurals consisted of furfural and 5-hydroxymethylfurfural;the phenols consisted of 2-methoxyphenol,2,6-dimethoxyphenol,phenol,and a small amount of catechol,4-ethylphenol and 4-ethylguaiacol;the acids consisted of formic acid,lactic acid,acetic acid,propionic acid and levulinic acid.Solid phase extraction and ion-exchange resin were employed to treat the hydrothermal liquefaction products and optimize the pretreatment method in the present study.The enrichment and separation effects of C18 column and Oasis HLB solid phase extraction column on the furfurals and phenols were discussed.The results presented that Oasis HLB column had a better separation effect on the furfurals,C18 had a better separation effect on the phenols except catechol and hydroquinone.In order to achieve a better effect,Oasis HLB column was used to separate the phenols and furfurals.Amberlite IR-120 cation exchange resin was used to separate the acids,furfurals and phenolic substances.After water leaching and methanol eluting,the sequence of separation was the acids,furfurals and phenols.Considering the actual working process,the solid phase extraction had a higher consumption of organic reagents,and the ion-exchange resin had a lower recovery rate but more likely to regenerate.With comprehensive consideration,ion exchange resin method was more economical and environmental friendly.