The dramatic fluctuations of oil cost and climate change have together concentrated political and scientific attention on the search of alternative fuels. The aim of this work is to recycle waste paper for producing bioethanol. The production process includes two main stages: the conversion of polysaccharides into simple sugars and the fermentation of these sugars into ethanol. In order to maximize the total sugars content, the parameters of both thermal pretreatment and acid hydrolysis steps are optimized by using the response surface methodology combined with Box–Behnken design. In the thermal pretreatment stage, temperature (100–140°C), residence time (20–60 min), and paper–water ratio (0.5–1.5% w/v) are adjusted. For acid hydrolysis step, temperature (60–100°C), reaction time (20–60 min), and amount of sulfuric acid (1–3% v/v) are the investigated parameters. Total sugars evolution is monitored during fermentation reaction using the yeast Saccharomyces cerevisiae under the optimal parameters of both pretreatment and acid hydrolysis steps. The optimum of thermal pretreatment step was found for the following operation conditions: Temperature = 100.46°C, time = 20.11 min, and paper–water ratio = 1.45% (w/v) with a yield of 48.69% (w/v) of total sugars while the best conditions for the acid hydrolysis step: Temperature = 96.31°C, time = 20.64 min, and amount of sulfuric acid = 1% (v/v), which led to a yield of 79.65% (w/v) of total sugars. Moreover, physicochemical and thermodynamic characteristics of the produced bioethanol (purity degree of 90% v/v) have shown a good agreement with the standards.

石油成本和气候变化的剧烈波动共同将政治和科学注意力集中在寻找替代燃料上。这项工作的目的是回收废纸以生产生物乙醇。生产过程包括两个主要阶段：将多糖转化为单糖，以及将这些糖发酵为乙醇。为了使总糖含量最大化，通过使用响应表面方法结合Box–Behnken设计来优化热处理和酸水解步骤的参数。在热预处理阶段，调节温度（100–140°C），停留时间（20–60分钟）和纸水比（0.5–1.5％w / v）。对于酸水解步骤，温度（60–100°C），反应时间（20–60分钟），硫酸的量（1-3％v / v）是研究的参数。使用酵母在发酵反应过程中监测总糖的释放在预处理和酸水解步骤的最佳参数下，酿酒酵母。对于以下操作条件，发现了最佳的热处理预处理步骤：温度= 100.46°C，时间= 20.11分钟，纸水比= 1.45％（w / v），产率为48.69％（w / v）。总糖，而酸水解步骤的最佳条件是：温度= 96.31°C，时间= 20.64分钟，硫酸量= 1％（v / v），收率达到79.65％（w / v）总糖。此外，所生产的生物乙醇的物理化学和热力学特性（纯度为90％v / v）已显示出与标准的良好一致性。