Wood and agricultural materials were delignified in either glycerol or alkaline glycerol in aqueous or non-aqueous media, in an autoclave or at atmospheric pressure, for the production of pulps. In a typical run, increasing the reaction temperature from 438 to 498 K raised the lignin loss from 55.5 to 88.0%, but decreased the yield of the remaining cellulose from 91.8 to 82.3%, while using 10% sodium hydroxide catalyst for 8 h reaction time for Ailanthus wood chips. In a non-catalytic run, the results were 47.9-76.8% for lignin loss, 96.2-93.3% for remaining cellulose, in the same range of temperature and reaction time.