8-04: Shock pretreatment

In shock pretreatment, an aqueous slurry of lignocellulosic biomass is placed in a cylindrical shock tube.  In the gas space above the aqueous slurry, an explosive is detonated.  The resulting high-pressure shock wave travels through the biomass and disrupts its physical structure at the microscopic level.  As a consequence, the enzymatic digestibility improves substantially.  Interestingly, by itself, shock treatment is not effective.  However, when combined with a chemical treatment, it is extremely effective and approaches enzymatic digestibilities achieved with ball milling, a very expensive mechanical pretreatment.  Because shock treatment is rapid and consumes very little energy, preliminary economic evaluations estimate that it is very inexpensive (~$5/ton).