Milk to milk bottles: Sustainable polymer grade lactic acid from residual dairy lactose

社会正在向行业和政府施压，要求减少、回收和再利用废物，并要求新技术和现有技术是环保的、可持续的和生物来源的。该项目的目标是将乳糖转化为乳酸，作为一种生物聚合物(聚乳酸)的原料：牛奶到奶瓶。在加拿大，乳制品行业的收入接近150亿美元，但它产生了乳糖水(0.05g/g)的废流，这些水中含有蛋白质、脂肪和矿物质。仅魁北克省每年就生产75000吨脱脂牛奶固体和渗透(废物)，这些废物要么被处理掉，要么被出口。在接下来的4年里，国际条约将限制这种废物的境外运输。出口/处理牛奶固体(65%乳糖)将产生接近1美元/公斤的成本，这是令人望而却步的昂贵。将这一流转化为附加值产品，将有助于面临压力的乳制品行业的经济健康。高乳糖含量使其成为生产燃料、特种化学品和单体的有吸引力的生物原料。生物燃料(甲烷、发酵乙醇)和合成气是一种选择，但如果没有政府的财政支持，经济诱因很低，资本和运营成本太高。 该项目不是将乳糖分解成简单的分子，而是寻求尽可能多地保持化合物的功能，并将以乳酸为目标。酸催化剂对乳糖(和其他糖)进行水解和羟化。该项目将探索几种催化剂和转盘反应器技术来生产浓缩蒸气乳酸，这是一种新兴的食品、化妆品、化学品和制药行业的平台化学积木。例子包括丙烯酸(2300美元/吨)和散装生物化学品。乳酸市场预计将以每年11%以上的速度增长，预计到2025年销售额将达到130亿美元。乳酸的起价为1700美元/吨，生物聚合物聚乳酸的售价超过3000美元/吨。 虽然乳糖发酵生产乳酸已经实现了商业化，但生产率低，资金投入高。我们预计，通过应用旋转圆盘反应堆，可以提高反应速度，从而减少资本，从而节省数量级的成本(关闭经济)。这种顽固的反应需要很高的热量和传质速率来接触乳糖和催化剂。在传统的沸腾床、固定床、浆体和滴流床反应器中，流体和催化剂之间的传质基本上取决于速度，速度大约为1m/S--比旋转圆盘的速度低几个数量级。加拿大化工和能源行业中实践的其他气-液、液-液和气-液-液系统也是其他可能的应用。

Society is pressuring industry and government to reduce, recycle, and reuse waste and are demanding that new and existing technologies are environmental, sustainable, and biosourced. The objective of this project is to convert lactose to lactic acid that will serve as a feedstock for a biopolymer (polylactic acid): milk to milk bottles. Revenues from the dairy industry approached 15 billion$ in Canada but it it produces a waste stream of lactose water (0.05 g/g) in water together protein, lipids, and minerals. Quebec alone produces 75000 tonnes of non-fat milk solids and permeates (waste) per year that is either disposed of or exported. In the next 4 years, international treaties will restrict shipments of this waste outside national borders. To export/dispose of the milk solids (65 % lactose) will incur a cost approaching 1 $/kg, which is prohibitively expensive. Converting this stream to a value-added product will contribute to the economic health of the dairy industry that is under pressure. The high lactose loading makes it an attractive bio-feedstock to produce fuels, specialty chemicals, and monomers. Biofuels (methane, ethanol via fermentation) and syngas are options but the economic incentive is low and the capital and operating costs are too high without financial support from government. Rather than breaking down lactose to simple molecules, this projects seeks to maintain as much of the functionality of the compound as possible and will target lactic acid. Acid catalysts hydrolyze and hydroxylate lactose (and other sugars). This project will explore several catalysts and spinning disk reactor technology to produce concentrated stream lactic acid, which is an emerging platform chemical building-block in the food, cosmetics, chemicals, and pharmaceutical industries. Examples include acrylic acid (2300 $/t) and bulk biochemicals. The market of lactic acid is forecast to increase annually by over 11 % and is expected to reach $13 billion in sales by 2025. The price of lactic acid starts at 1700 $/t and the biopolymer polylactic acid sells for more than 3000 $/t. Although fermentation of lactose to lactic acid is already practiced commercially, productivity is low and capital investment is high. We anticipate order of magnitude savings (shut down economics) by applying a spinning disk reactor that will increase reaction rates and thereby reduce capital. This recalcitrant reaction requires high heat and mass transfer rates to contact the lactose and catalyst. Mass transfer between fluid and catalyst in the conventional fluidized bed, fixed beds, slurries, and trickle bed reactors depend essentially on the velocity, which is on the order of 1 m/s - several orders of magnitude lower than what is possible with the spinning disks. Other gas-liquid, liquid-liquid, and gas-liquid-liquid systems, practiced in the Canadian chemical and energy industries, are other possible applications.