Abstract
This thesis describes a process for pretreating bagasse with diethylamine to enhance lignocellulose reactivity. The bagasse was soaked in diethylamine for 1, 3, 6, 12 and 24 hour time intervals, and the pressure was released slowly. The treated material was dried for 12 hours to remove the amine and then hydrolyzed for 72 hours with a mixture of cellulose enzymes. Six specially designed reactor vessels, and a temperature-controlled water bath were built to perform these experiments. This allows six different conditions (besides temperature) to be run simultaneously, thus decreasing the time between each "screening" experiment. The conditions which were screened in the diethylamine pretreatment experiments were: diethylamine loading, residence time, reactor temperature, water loading, and calcium hydroxide loading. Reactor temperature and residence time greatly affected bagasse reactivity, whereas water loading and diethylamine loading had only a minor effect. Adding calcium hydroxide to the diethylamine did not increase reactivity, but it allows the diethylamine to be recovered. In addition to the diethylamine experiments, ammonia was used to pretreat Coastal bermudagrass. This process involves soaking the cellulose fibers in liquid ammonia for several minutes and releasing the pressure explosively. Four different conditions were screened in this pretreatment study: ammonia loading, water loading, reactor temperature, and residence time. Of these four, increasing reactor temperature had the greatest benefit on bermudagrass reactivity. Residence time had the second greatest benefit on bermudagrass reactivity. Residence times between 45 minutes and 1 hour gave the highest sugar yields. Ammonia loading had only a minor influence on reactivity, whereas larger water loadings caused reactivity to decrease.
Holthus, Robert Earl (1993). Diethylamine and ammonia pretreatment of lignocellulose. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -H758.