TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The method involves mixing the least one lignocellulosic agricultural residue with the plant fiber material prior to treatment. The plant fiber material is defibrated prior to treatment. The method further involves: the treating step:(a) including admitting into a batch-steam explosion reactor saturated steam from a steam source until the mixture ofstep (b) is about 200degreesC; reacting the mixture for 2 - 5 minutes; decompressing the mixture into a separator; separating out a gaseous component of the mixture; and slurrying the mixture to about 20% solids, where hydrolyzing instep (c) is carried out at about 50degreesC, pH 5 for about 72 hours, and the organism in the fermentingstep (d) includes Escherichia coli KO11. The method involves mixing a plant fiber material comprising calcium carbonate with at least one lignocellulosic agricultural residue into a mixture such that the mixture is fermentably detoxified for ethanol production by the addition of the plant fiber material alone; and processing the mixture into ethanol. The method further involves slurrying the plant fiber material with water prior to the mixing step (b).Preferred Components: The at least one lignocellulosic agricultural residue further comprises a cotton gin waste; a corn stover; a rice hull; or a sugar cane bagasse. The plant fiber material comprises paper sludge. The paper sludge comprises an ash content of 5 - 30 mass% of the paper sludge, where the ash content includes the calcium carbonate at a minimum of about 5%. The plant fiber material comprises at least about 50% moisture.The paper sludge is fine paper sludge; coated paper sludge; coated fine paper sludge; recycle mixed office paper sludge; recycled newsprint; de-inked pulp mill sludge; de-inked paper mill sludge; or recycled paper sludge. The ratio of the at least one lignocellulosic agricultural residue to paper sludge is 1:1 - 5:1 (preferably 1:1). EXAMPLE - Recycled paper sludge (RPS) containing about greater than or equal to50% moisture was mechanically mixed with the cotton gin waste (CGW). This mixture was loaded into a batch-steam explosion gun and saturated steam was admitted into the reaction chamber until the feed temperature was about 200degreesC. The steam source was then closed and the reaction was allowed to proceed for 2 - 5 minutes. The steam valve at the bottom of the reactor was then opened and the biomass was explosively decompressed into a cyclone separator. The cyclone separated the steam and other gaseous components from the fiber fraction. The fiber fraction was slurried to about 20% solids and hydrolyzed with cellulase enzyme at about 50degreesC, pH 5 for about 72 hours. The hydrolysate was fermented with E. coli KO11 to ethanol. In the absence of RPS the highest ethanol yield was about 50 gallons per ton of CGW, whereas with the inclusion of the RPS, the glucose concentration in the mixture indicated that the ethanol yield increased considerably, with results of up to 90% of the ethanol yield being achieved.