Electrochemical Pretreatment Of Corn Stover

A lot of agricultural straws are produced in the world each year. Seriousenvironmental problems would follow if the straws were treated or disposedimproperly. In recent decades, all the world has spent lots of resources in theproduction of new energy from agricultural straws so that the shortage crisis of foilenergy would be relieved and the agriculture straws could be dealt proper. Before theenergy produced, pretreatment of straws must be taken. The dilute acid pretreatmentand alkaline pretreatment are chosen popularly. However, unfavorable pH for thefermentative microorganisms unless neutralized after the pretreatments.In this study, an electrochemical system was employed with Ti/IrO2-Pt plate asthe anode and Ti plate as the cathode for the treatment of corn stover. NaCl wasconsidered to be the best electrolysis among NaCl, NaNO3and Na2CO3, comparingthe effectiveness of reducing sugars production and the enzymatic hydrolysis of cornstover which was treated in electrochemical system with NaCl, NaNO3and Na2CO3electrolysis, respectively. The optimum conditions using the Taguchi methodologywere electrode spacing, current density, and NaCl addition of10mm,30mA/cm2, and2000mg/l, respectively. The recovery of reducing sugars under optimum conditionsreached0.610mg/ml at180min. The increasing temperature and the variation in pHwere beneficial to the production for the reducing sugars during the electrolysisprocess. The morphologic analysis of corn stover after the pretreatment showed thatthe structure of the lignocelluloses was destroyed, part of cellulose was degraded, anda decrease in the CrI from0.4396to0.3493was found. The electrolysis wasdominated by the indirect oxidation because of HOCl and Cl+formations.Hemicellulose was easier degraded than cellulose. The final formation of hydrocarbonwas carbon dioxide. Compared to ozone pretreatment and sodium hypochloritepretreatment, the electrochemical pretreatment showed it was a high efficientadvanced oxidation process.