8-26: Magnesium chloride pretreatment for enzymatic hydrolysis of cattails

It has been discovered that chloride salts as Lewis acids can react with cellulosic biomass directly, in aqueous phase or in ionic liquid with excellent selectivity, and chloride salts promote a few reactions while suppressing most of the other reactions. For this study, magnesium chloride pretreatment of aquatic plant cattails was studied using a Dionex accelerated solvent extractor (ASE) varying salt concentration (0.1 M and 0.4 M), treatment temperature (140-180 °C) and residence time (5-15 min). The use of aquatic plant cattails to produce biofuel will add value to land and reduce emissions of greenhouse gases by replacing petroleum products. Up to 33% of the cattails was dissolved during pretreatment over the temperature range of (140°C-180°C) and times intervals of (5-15 minutes). The yield of extractable products obtained from the pretreatment process increased as the final temperature and treatment time. The xylan fraction of cattails can be completely removed when cattails were pretreated above 180 °C, and approximately 35% of total xylan was directly hydrolyzed to the xylose monomer. When cattails was pretreated with 0.4M MgCl₂ solution at 180 °C for 15 min, then hydrolyzed for 48 h with a cellulase loading of 15 FPU/g glucan, the highest glucose yield of 55.5% were reached. The advantages of the magnesium chloride pretreatment are lower corrosion to equipment and lower xylanase demand. The current magnesium chloride pretreatment process of cattails will be further optimized to improve its efficiency, and makes the process more economically sound.