PFI: AIR-TT: Ultrapure Lignins Recovered from Paper-Mill Black Liquors as Renewable Biopolymers

这个PFI：空气技术翻译项目专注于翻译一种环境友好型提取工艺的发明，用于生产超纯木质素，以满足社会对廉价、可再生生物聚合物的需求。木质素是世界上最丰富的生物聚合物之一(仅次于纤维素)，但由于其芳香性质而独一无二，这赋予了它特殊的性质。随着热酸水溶液木质素净化(Alpha)工艺的发明，现在可以从生物质副产品流(如造纸厂的黑液)中回收杂质水平非常低、分子量可控(即“超纯”)的木质素。这些超纯木质素有可能在广泛的应用中取代石油衍生的不可再生聚合物，包括泡沫、涂料和碳纤维。今天，市场上出售的所谓硫酸盐木质素的金属含量是超纯木质素的100多倍(即10000ppm对100ppm)，几乎没有或根本没有控制分子量。在这个项目中，阿尔法将与木素企业的连续液体木质素回收和提纯(SLRP)工艺相结合，将黑液转化为硫酸盐木质素，然后再转化为超纯木质素。这两个过程都使用可再生的水溶液醋酸(SLRP作为酸化剂，Alpha作为萃取剂)，而且都是连续过程，因此与当前的间歇技术相比，总成本将降至最低。该项目解决了几个技术差距，以将Alpha从发现转化为商业应用。首先，需要更好地了解SLRP过程中形成的水合液-液相通过含水醋酸转化为粗硫酸盐木质素的基本原理，以便优化操作条件，以便与Alpha集成。其次，需要设计和建造用于Alpha原型的液-液萃取、混合和沉淀装置，以便在2-3个阶段获得所需的超纯木质素的纯度和分子量。第三，需要解决将Alpha原型与现有SLRP原型装置集成的技术困难，该项目的最终目标是从典型的针叶木或阔叶木黑液中生产10-20公斤/天的超纯木质素。本科生、研究生和博士后将通过与木质素企业的互动，获得技术翻译和小公司成功创业的经验。

This PFI: AIR Technology Translation project focuses on translating the invention of an environmentally friendly extraction process for producing ultrapure lignins to fill the need in society for inexpensive, renewable biopolymers. Lignin is one of the world's most abundant biopolymers (second only to cellulose), but is unique because of its aromatic nature, giving it special properties. With the invention of the Aqueous Lignin Purification with Hot Acids (ALPHA) process, lignins with very low levels of impurities and of controlled molecular weight (i.e., "ultra pure") can now be recovered from biomass by-product streams, such as the black liquor from paper mills. These ultrapure lignins have the potential to replace petroleum-derived, nonrenewable polymers in a wide variety of applications, including foams, coatings, and carbon fibers. Today, the so-called Kraft lignins available on the market have over 100 times the metals content of ultrapure lignins (i.e., 10,000 vs 100 ppm), with little or no control of molecular weight. In this project, ALPHA will be integrated with the Sequential Liquid-Lignin Recovery and Purification (SLRP) process of Lignin Enterprises to convert black liquor to Kraft lignin and then to ultrapure lignin. Both processes use renewable aqueous acetic acid (SLRP as an acidification reagent and ALPHA as an extractive solvent) and both are continuous processes, so overall costs will be minimized compared to the current batch technologies.This project addresses several technology gaps so as to translate ALPHA from discovery towards commercial application. First, the fundamentals of the conversion of the hydrated liquid-liquid phase formed in the SLRP process to raw Kraft lignin via aqueous acetic acid needs to be better understood, so that operating conditions can be optimized for integration with ALPHA. Second, the liquid-liquid extraction, mixing-and-settling setup for the ALPHA prototype needs to be designed and constructed so as to obtain the desired purities and molecular weights of ultrapure lignin in 2-3 stages. Third, the technical difficulties of integrating the ALPHA prototype with the existing prototype SLRP unit need to be addressed, the final objective for this project being the production of 10-20 kg/day of ultrapure lignin from a typical softwood or hardwood black liquor. Undergraduate, graduate and post-doc students will receive experience in both technology translation and the successful start-up of a small company through their interaction with Lignin Enterprises.