Isolation Of Lignin From Bamboo (Phyllostachys Pubescens) And Prepare Biodiesel Antioxidant From Liquefied Mixture Of Bamboo Lignin

Lignin is widespread in the plant kingdom, only less than cellulose in the content. As part of the aromatic compounds, lignin is a very impoatant organic raw material in the industry. Liquefied the lignin to produce valuable chemical materials is an important way in transforming lignin into value-added products. Oxidation stability of biodiesel is short, shelf life is poor, and the current price of biodiesel antioxidants is high. This paper liquefied bamboo Acetic Acid lignin by atmospheric fast liquefaction methods, and then extract the phenolic compounds from the liquefied product to produce biodiesel antioxidants.In order to research the effect of different technological parameters on the separation of bamboo lignin, series of single factor experiments had been done in present investigation. This result showed that the optimum extraction conditions is: 90% aqueous AcOH,3%H2SO4, ratio of liquor to bamboo residue 12, pulping temperature 106℃, and pulping time 2.5h. The UV, FT-IR, and NMR spectra results shows that the functional groups and chemical bond in MWL and Acetic Acid lignin are quite similar, excepting acetic acid lignin has more phenolic hydroxyl groups, so its chemical activity is more stonger, which is an advantage for further utilization.Based on the preliminary results from liquefaction of bamboo Acetic Acid lignin, ethylene glycol was chosen and used as the liquefaction solvent. And the effect of the main parameters on lignin liquefaction of total phenol content had been studied, such as the liquefaction temperature, liquefaction time, catalyst amount, solvent/lignin (w/w) ratio. On this basis, according to Box-Behnken central composite design principle, using three factors and three levels of response surface methods to further optimize the extraction of acetic acid lignin phenols liquefaction process. The optimum conditions were optimized as follows:liquid temperature (A) 170℃, the amount of catalyst (B) 3.53%, liquid to solid ratio (C) 12, verify test shows that the total yield of phenol test values and predicted value is consistent in the optimum conditions and the equation fits better with the actual values. So analyze and predict the total phenolic content of lignin liquefaction products by Response Surface Method was reasonable and feasible.Phenolic extracts on oxidation stability of biodiesel affect experimental results show that phenolic extracts have good anti-oxidant effect on biodiesel, the antioxidant capacity was stronger than VC and BHA, and antioxidant effect of low concentrations was more obvious than TBHQ. The oxidation stability of biodiesel could meet the standard of EN 14112-200 when 0.15% of the phenolic extracts was added into the biodiesel. Phenolic extracts have good antioxidant effect on biodiesel prepared from different raw materials, when the dosage was 0.15%, the oxidation stability of soybean oil biodiesel could meet the standard and when the dosage was up to 0.25%, the oxidation stability of waste oil biodiesel can meet EN14112-2003 standard. Phenolic extracts should be stored under low temperature conditions, and in this condition the quality was more stable. In order to ensure good anti-oxidant effect, the phenolic extracts as an biodiesel antioxidant should be add as soon as possible and minimize the storage time. Phenolic extracts at low temperature have good long-term antioxidant effect.