Hydrolysis Cassava Residue To Sugar And Coupled To Acetogenic Process

The main components of cassava residue are starch, cellulose, hemicellulose, lignin, and contain a small amount of axunge and protein, the use of space is still quite large. It is suitable for the sustainable development of social demand to use biological technology to converte cassava residue which containing a large amount of organic matter into biological energy and industrial chemicals, for example volatile fatty acid, on the other hand, it also can solve the handling problem of cassava residue, so as it can promote the development of agriculture and other related industries.First, this article studied the effect of13kinds of hydrolisis methods on hydrolysising cassava residue, and studied the effects of different factors on hydrolysising cassava residue to sugar with dilute nitric acid, sodium hydroxide and composite enzyme method. And then coupling process of acetogenesis/homoacetogenesi were used to fermentate the cassava residue after hydrolysising to produce acetic acid, explored the effects of different hydrolysis method, concentration of substrate and vaccination on the production of acid. The experimental results showed:(1) The effect of hydrolisis for cassava residue with diluted acid was better in13different kinds of methods, of0.5%HNO3being the best, at the hydrolisis temperature and time of160℃and10min respectively, the concentration and yield of glucose of22606.55mg/L and27.13%, total sugar of33682.78mg/L and40.4%. The effect of hydrolysis for cassava residue with NaOH and hot water pressure were not obvious, with3%NaOH, at the hydrolisis temperature and time of180℃and3h respectively, the concentration of glucose and total of monosaccharide at2297.13mg/L and3335.34mg/L, and the yield at2.76%and 4.00%respectively; In hydrolysis with enzymes, cellulases and emicellulase with1%H2SO4being the best, the amount of cellulase and hydrolisis time of120U/g and66h respectively, the concentration of glucose and total of monosaccharide at22598.55mg/L and26624.21mg/L, and the yield at27.12%and31.95%.(2) Compared the effect of anaerobic fermentation of coupling process to produce acid by using the cassava residue after hydrolysis with0.5%HNO3,3%NaOH, cellulases and emicellulase with1%H2SO4and untreated. The effect of acid-producing was best, when hydrolisising the cassava residue with0.5%HNO3befor fermentation, the highest concentration of acetic acid and VFA were3.50g/L and6.76g/L respectively in phase A, and they were1.18g/L and2.14g/L respectively in phase H. The yield of acetic acid and total VFA were0.0952g/g and0.1718g/g respectively.(3) Compared the effect of acid-producing between the substrate concentration for (30,40,50,60) gTS/L, the concentrations of acetic acid and total VFA increased first with substrate concentration increasing, and then reduced. when the substrate concentration was50gTS/L, the concentrations of acetic acid and total VFA were highest, the concentration of acetic acid and total VFA were3.50g/L and6.76g/L respectively in phase A, and they were1.18g/L and2.14g/L respectively in phase H.(4) Compared the effect of acid-producing between the vaccination concentration for (6,10,14,18) gTS/L, the concentrations of acetic acid and total VFA increased with substrate concentration increasing. When the vaccination concentration was18gTS/L, the concentrations of acetic acid and total VFA were highest, the concentrations of acetic acid and total VFA were3.74g/L and7.48g/L respectively in phase A, and they were1.25g/L and2.04g/L respectively in phase H. The yield of acetic acid and total VFA were0.1014g/g and0.1867g/g respectively.