A continuous and modular process converts lignocellulosic materials for the production of
ethanol principally and / or chemicals such as
methanol,
butanediol,
propanediol,
hydrocarbon fuel, etc. Renewable
lignocellulosic biomass such as but not all inclusive hardwoods (gum,
beech, oak, sweet gum, poplar,
eucalyptus, etc.), soft woods (pines, firs, spruce, etc.), corn stovers, straws, grasses, recycled papers, waste products from pulp and paper mills, etc can be used as feedstock. The process is designed to be modular and the feed
entry point can be selected to adapt to different
biomass feedstock.
Lignocellulosic biomass such as
hardwood and
softwood are subjected to chemical / pressure treatment stages using potent and selective chemicals such as
sodium chlorite /
acetic acid (
anhydrous) and
chlorine /
chlorine dioxide to separate the main components—
lignin,
cellulose (glucose) and hemicelluloses (
xylose,
arabinose,
galactose)—into three process streams. The separated carbohydrates are further subjected to washing, cleaning,
neutralization, and / or mild
hydrolysis and subsequently fermented to produce
ethanol.
Residual lignin and extractives remained with the
cellulose are removed by
chemical treatment steps to enhance the fermentations of
cellulose. Pre-
hydrolysate after
neutralization to neutralize and remove toxic components such as
acetic acid,
furfural, phenolics, etc. containing (
xylose,
arabinose,
galactose) and hexoses (glucose) can be either separately or together with the purified cellulosic fraction fermented to produce
ethanol. Approximately 100 gallons of ethanol, suitable to be used as a fuel, can be produced from one dried
ton of wood. Significant amount of
lignin are separated as a by-product and can be converted to
hydrocarbon fuel, surfactant, drilling aid, or can be incinerated for generation of power and steam.