Ethanol production from various agricultural and forest residues has been widely researched, but there is limited information available on the use of mixed hardwood for ethanol production. The main objective of this study is to assess the impact of time on the steam explosion pretreatment of waste wood (mixed hardwood) and to determine the convenience of a delignification step with respect to the susceptibility to enzymatic hydrolysis of the cellulose residue and the recoveries of both cellulose and hemicellulosic sugars. Delignification did enhance enzymatic hydrolysis yields of steam exploded waste wood. For steam explosion pretreatment times of 3 and 5 min, the recovery yield of hemicellulosic-derived sugars decreased. The effective hemicellulose solubilization does not always result in high recoveries of hemicellulose-derived sugars in the liquid fractions due to sugar degradation. In the steam explosion pretreatment times of 3 and 5 min, where hemicellulose solubilization exceeded 95%, but sugar recoveries in the liquid fraction remained below 30%. Cellulose to glucose yield losses were less significant than hemicellulosic-sugar losses, with a maximum loss of 24% at 5 min. Up to 80% of the lignin in the original wood was solubilized, leaving a cellulose-rich residue that led to a concentrated cellulose to glucose yield solution (about 50 g/L after 72 h enzymatic hydrolysis in the best case). The maximum overall process yield, taking into account both sugars present in the liquid from steam explosion pretreatment and cellulose to glucose yield from the steam exploded, delignified and hydrolyzed solid was obtained at the lowest steam explosion pretreatment time assayed.

The alkaline hydrolysis of alkyl alkylphosphinate and alkyl phenylphosphinates have been studied at room temperature. The hydrolysis proceeded as an one-stage reaction(SN 2) and involved a nucleophilic attack of the hydroxyl ion on the phosphorus atom. And the length of the alkoxy group in the phosphinate esters affected on hydrolysis. Therefore, the alkaline hydrolysis may be used as a method to decompose the chemical agents.