NOVELTY - Preparing ethanol from a dry lignocellulosic biomass comprises: (a) converting the biomass to a particulate matter; (b) preparing a mixture of the matter in water; (c) contacting the mixture with a blend of acids at a desired temperature for a desired time period to obtain a first stream; (d) adjusting pH of the first stream with a base to obtain a neutralized stream; (e) contacting the neutralized stream with one or more of cellulolytic enzymes; (f) subjecting the final stream to a hexose fermenting yeast; and (g) separating ethanol from the first fermented stream.    USE - The process or system is useful for preparing ethanol from dry lignocellulosic biomass (claimed).    ADVANTAGE - The method has advantages like: (1) low level of inhibitors that do not limit the growth of microbes; (2) more benign and economic processing conditions of lignocellulosic materials (LCM); and (3) higher efficiency of conversion of sugars to ethanol in a two step fermentation process.    DETAILED DESCRIPTION - Preparing ethanol from a dry lignocellulosic biomass comprises: (a) converting the biomass to a particulate matter; (b) preparing a mixture of the matter in water; (c) contacting the mixture with a blend of acids at a desired temperature for a desired time period to obtain a first stream; (d) adjusting pH of the first stream with a base to obtain a neutralized stream; (e) contacting the neutralized stream with one or more of cellulolytic enzymes at desired temperature for a desired time period to obtain a final stream; (f) subjecting the final stream to a hexose fermenting yeast to obtain a first fermented stream; (g) separating ethanol from the first fermented stream by distillation to obtain a spent stream; (h) subjecting the spent stream to a pentose fermenting yeast to obtain a final fermented stream; and (i) separating ethanol from the final fermented stream by distillation. An INDEPENDENT CLAIM is a system for preparing ethanol from a dry lignocellulosic biomass comprising: (a) a mechanical mechanism for converting the biomass to a particulate biomass; (b) a soak tank for soaking and washing the particulate biomass in water; (c) a digester for pre-treating the soaked biomass with an acid or a mixture of acids to obtain a first stream with pentose sugars released from hemi-cellulose part of the biomass; (d) a reactor for adjusting pH of the first stream to obtain a neutralized stream and simultaneously liquefying the neutralized stream with cellulolytic enzymes to obtain a hydrolyzed stream; (e) a provision in a second reactor for treating the hydrolyzed stream with additional cellulolytic enzymes to obtain a final stream with hexose sugars released from cellulose part of the biomass; (f) a first bioreactor for treating the final stream with a microorganism fermenting hexose sugars to obtain a first fermented stream; (g) a distillation mechanism for recovering aqueous ethanol from the first fermented stream to obtained a spent stream; (h) a second bioreactor for treating the spent stream with a microorganism fermenting pentose sugars to obtain a final fermented stream; (i) the distillation mechanism for further recovering aqueous ethanol from the final fermented stream and a waste stream; (j) a rectification mechanism to convert the aqueous ethanol to a concentrated ethanol stream; (k) a filter press mechanism for separating water from the waste stream to obtained a solid stream as a boiler fuel; and (I) a purification mechanism for purifying the separated water to reusable water.