Urgently need technical information on the conversion of fibers into sugars

The method of first glycosylating cellulose using cellulase and then fermenting it into alcohol through yeast is known as the separate hydrolysis and fermentation (SHF) approach. This method can utilize the optimal conditions for hydrolysis and fermentation separately (50°C and 30°C respectively), but the products generated by enzymatic hydrolysis (fiberdextrin and glucose) will feedback inhibit the hydrolysis reaction. As the glucose concentration increases during the hydrolysis process, the enzymatic reaction quickly slows down due to product inhibition, resulting in incomplete reaction. Adding β-glucosidase can prevent the accumulation of cellobiose and thereby inhibit the activity of exocellulases. Ghose et al. concentrated the cellulase from the high-yielding strain Trichoderma viride QM9123 by 5–8 times, added it to a 30% suspended slurry of ground lignocellulose, and carried out continuous saccharification in a reactor. The glucose produced was separated using an ultrafiltration membrane, thereby eliminating product inhibition and increasing the reaction rate; the glucose concentration in the effluent reached over 10%. However, the industrialization of membrane technology presents certain difficulties. Synchronous saccharification fermentation (SSF), which involves inoculating yeast for alcohol fermentation along with cellulase, allows the glucose produced to be immediately fermented into alcohol by the yeast. By eliminating product inhibition, the continuation of cellulose saccharification is not hindered, and the alcohol yield can be significantly increased. This is what is known as simultaneous saccharification and fermentation technology (SSF). The key to SSF technology is selecting the most suitable yeast. The optimal temperature for enzymatic hydrolysis is around 50°C, whereas the optimal fermentation temperature for conventional winemaking is usually around 30°C. Choosing heat-resistant yeast is beneficial for the application of SSF technology. The best results obtained by the U.S. **National Renewable Energy Laboratory (NREL)** using Saccharomyces cerevisiae for fermentation were achieved at 38°C. Under optimal enzyme, yeast, and reaction conditions, over 80% of cellulose can be converted into ethanol. To increase the fermentation concentration of cellulosic ethanol and reduce the inhibitory effect of ethanol on the fermentation process. Chen Hongzhang and others from the Institute of Process Engineering, Chinese Academy of Sciences, proposed a technical system combining solid-state enzymatic hydrolysis of cellulose with liquid fermentation for ethanol production, which was granted a Chinese invention patent in 2003 (ZL 0249484.3). New technologies reduce the excess free cellulase in liquids, thereby lowering the amount of cellulase needed and its associated costs ； Reduced the amount of wastewater in the residues resulting from cellulose solid-state enzymatic hydrolysis fermentation ； Saccharification and fermentation take place in different sections of a reactor at distinct intervals, which facilitates the optimization of the optimal operating temperatures for each process ； Overcame the drawback that the solid state is unfavorable for rapid ethanol fermentation ； A triple coupling process of enzymatic saccharification – liquid fermentation of ethanol – adsorption separation was implemented, reducing the production cost of ethanol.

Sure, generally there are the following methods: strong acids, dilute acids at high temperatures, dilute acids with enzymes, and steam explosion； However, the costs are all very high, and the sugar concentration is relatively low, making it impossible to achieve the effects of sugar production from starch. Various types of sugars are obtained through hydrolysis, and if sugar is to be produced solely, separation becomes difficult ； In short, cellulose technology is still a long way away from being put into industrial use. Although researchers claim that it can be commercialized in just 5 years, it seems that there will always be another 5 years of progress needed before that happens.

This isn’t just hearsay; it’s been done quite a lot both domestically and internationally. Upstairs, they might have mixed up pretreatment and saccharification a bit.

There are many preprocessing methods, including physical, chemical, and biological ones. . Hydrolysis is basically acid hydrolysis and enzyme hydrolysis. Enzymatic hydrolysis is probably best done by Cargill and Novozymes.