Milled WS (124.2 g/L, dry basis) was
slurried in 0.75% (v/v) H2SO4and pretreated in the tube reactors
at 160C for 20 min holding time. The heating and cooling times
of the reactors were around 15 min each. The reactors were cooled
using chilled tap water. One set of pretreatment generated 20 L of
pretreated material.