An ammonia pretreatment prior to IL dissolution improved delignification of biomass and enhanced recyclability. The rice straw (particle size 2-5 mm) was first treated with ammonia (10%) at 100°C for 6 h. After filtering and drying steps, it was dissolved in [EMIM][OAc] at 130°C for 24 h. The ammonia pretreatment step reduced the time for complete dissolution in IL from 24 to 6 h. It increased slightly the amount of regenerated cellulose after the IL treatment for <24 h. The major improvement was the significant increase in the glucose conversion rate of 97% (compared to the amount of regenerated cellulose) with the ammonia pretreatment, compared to the 78% rate without ammonia pretreatment. This improvement allowed for a significant reduction in the amount of cellulases necessary for cellulose hydrolysis: despite a reduction of the cellulase concen­tration by a factor 10, the cellulose conversion rate remained at 83% [46].