Cellulose ethanol internal circulation production method without pretreatment

Title: Method of production cycles without pretreatment of the cellulosic ethanol. The present invention belongs to the field of renewable biomass energy, the production cycle category. And more particularly relates to a catalyst which does not require sulfuric acid concentrated sulfuric acid catalyzed hydrolysis of the pretreated lignocellulosic feedstock to produce ethanol, a neutralizer circulating lime and carbonized lignin production thereof. Pulverized dried plant straw (1) Liquefaction of concentrated sulfuric acid (2) Hydrolysis (3), with lime and (4), isolated by filtration (5), a fermentation filtrate (6), distillation (7) dehydration of fuel ethanol, dried residue (8), pyrolysis (9), reducing (10) sulfur dioxide (11), is converted to sulfuric acid (12) with the back, and calcium oxide used in the back (4) or the production of cement, lime and sulfuric acid recycling , utilization of lignin, forming a wood fiber - sulfate - CaO - lignin within the circulation system of carbon, 99.5% recovery of the catalyst, carbon reduction of 80% or self-sufficiency, energy consumption reduced by 30% for cellulosic ethanol industrialization provide the basis for commercial production.