The bales were opened and the corn straw was chopped into 3- to 10-cm particles designated as untreated corn straw (U-CS). The U-CS (680 kg) was mixed for 15 min in a mixing wagon with 60 kg of concentrated NaOH solution (48% wt/wt) and
260 kg of water to create 1 t of 5% NaOH T-CS.