Abstract：
Microcrystalline cellulose (MCC) was successfully synthesized from sugarcane bagasse using a rapid, low-temperature hydrochloric acid (HCl) gas treatment. The primary aim was to develop an energy-efficient \"green\" cellulose extraction process. Response surface methodology optimized the liquid-phase hydrolysis conditions to 3.3 % HCl at 117 °C for 127 min to obtain MCC with 350 degree of polymerization. An alternative gas-phase approach utilizing gaseous HCl diluted in hot 40 °C air was proposed to accelerate MCC production. The cellulose pulp was moistened to 15-18 % moisture content and then exposed to HCl gas, which was absorbed by the moisture in the cellulose fibers to generate a highly concentrated acidic solution that hydrolyzed the cellulose. The cellulose pulp was isolated from depithed bagasse through soda pulping, multistage bleaching and cold alkali purification. Hydrolysis was conducted by saturating the moist cellulose fibers with gaseous HCl mixed with hot air. Extensive analytical characterization using FT-IR, XRD, SEM, TGA, DSC, particle size, and porosity analyses verified comparable physicochemical attributes between MCC samples prepared via liquid and gas phase methods. The gas-produced MCC revealed 85% crystallinity, 71 Å crystallite dimensions, and thermally stable rod-shaped morphology with an average diameter below 200 μm. The similar material properties validate the proposed gas-based technique as an equally effective yet more energy-efficient alternative to conventional aqueous acid hydrolysis for fabricating highly pure MCC powders from lignocellulose. This sustainable approach enables the value-addition of sugarcane bagasse agro-industrial residue into cellulosic nanomaterials for wide-ranging industrial applications. In summary, the key achievements of this work are rapid MCC production under mild temperatures using HCl gas, optimization of liquid phase hydrolysis, successful demonstration of gas phase method, and extensive characterization verifying equivalence between both protocols. The gas methodology offers a greener cellulose extraction process from biomass.
摘要：
用甘蔗渣快速合成微晶纤维素(MCC),低温盐酸(HCl)气体处理。主要目的是开发一种节能的“绿色”纤维素提取工艺。响应面法优化了液相水解条件，使其在117°C下达到3.3％HCl127分钟，以获得聚合度为350的MCC。提出了一种替代的气相方法，该方法利用在40°C的热空气中稀释的气态HCl来加速MCC的生产。将纤维素纸浆润湿至15-18％的水分含量，然后暴露于HCl气体，其被纤维素纤维中的水分吸收以产生水解纤维素的高度浓缩的酸性溶液。通过苏打制浆从脱水的甘蔗渣中分离出纤维素纸浆，多级漂白和冷碱净化。通过用与热空气混合的气态HCl使潮湿的纤维素纤维饱和来进行水解。使用FT-IR进行广泛的分析表征，XRD,SEM,TGA,DSC,颗粒大小,和孔隙度分析验证了通过液相和气相方法制备的MCC样品之间具有可比性的物理化学属性。气体产生的MCC显示出85%的结晶度，71的微晶尺寸和热稳定的棒状形态，平均直径低于200μm。相似的材料特性验证了所提出的基于气体的技术是一种与常规水性酸水解相同的有效且更节能的替代方法，用于从木质纤维素制造高纯度的MCC粉末。这种可持续的方法可以将甘蔗渣农业工业残留物增值到纤维素纳米材料中，用于广泛的工业应用。总之,这项工作的主要成果是使用HCl气体在温和温度下快速生产MCC，优化液相水解，气相法的成功示范，和广泛的表征验证两个协议之间的等价性。气体方法提供了从生物质中提取更绿色的纤维素的方法。
