Novel approach to high yielding value added products utilizing crude glycerol a major byproduct of the rapidly expanding biodiesel industry

生物柴油等可再生燃料的使用正在增加——事实上，在加拿大，法规要求至少5%的汽油和2%的柴油是由“可再生”燃料制成的。这将在25年内减少4740万吨二氧化碳当量的温室气体（GHG）排放，这是一个可观的数字。生物柴油生产包括一种有趣且有用的副产品：甘油。目前，这种糖醇在其原始状态下被用作动物饲料的添加剂。由于价格下降，将其提炼为“科技级”的成本过高。但是，如果甘油可以转化为塑料或平台化学品等增值产品呢？这将取代一些基于化石燃料的产品，减少生产过程对环境的影响，并为生物柴油行业提供额外的收入来源。然而，传统的化学催化剂工艺价格昂贵，转化率低，而且对环境影响很大。已经有相当多的研究将微生物作为一种生物转化方法，但由于粗甘油流中存在杂质，产量不够高，使其在经济上可行。目标是开发一种简单的纯化方法，达到不抑制随后的生物转化的水平。然后，使用适当的微生物，我们将从甘油生产两种增值产品：聚3-羟基烷酸酯（PHA），生物塑料中的一种成分；琥珀酸（SA）是一种平台化学物质，作为许多其他化学物质的起点。选择这些产品是因为它们确定了理论最大产量，并且因为它们在未来几年的市场需求不断增长。本研究有三个目标：(1)研究三种不同的粗甘油工业流，以确定最佳的纯化方法，使微生物能够生长；(2)从生成的甘油中成功高产出PHA和SA；(3)研究以纯形式生产这些化学物质的下游工艺，并将这些工艺整合到现有的生物柴油工厂中。这项研究的成功完成将有助于生物柴油行业为其副产品找到新的用途（这将增加收入），提高这些产品的生产效率，并间接减少生物柴油生产对环境的影响。此外，该项目将为加拿大培养跨学科领域的HQP（硕士和博士）。

The use of renewable fuels like biodiesel are on the rise – in fact in Canada, regulations require that at least 5% of gasoline and 2% of diesel fuel be made of “renewable” fuel. This will reduce greenhouse gas (GHG) emissions by 47.4 million tonnes carbon dioxide equivalent over 25 years, which is a significant amount. Biodiesel production includes an interesting – and useful – byproduct: glycerol. This sugar alcohol is currently used in its crude state as an additive in animal feed. Refining it to “tech grade” is cost prohibitive due to falling prices. But what if glycerol could be converted into value-added products like plastics or platform chemicals? This would replace some fossil fuel-based products, reduce the impact of the production process on the environment, and provide the biodiesel industry with an additional revenue stream. However, traditional chemical catalyst processes are expensive, have low conversion rates, and significantly impact the environment. There has been considerable research into using microorganisms as a bioconversion method, but yields have not been high enough due to impurities present in the crude glycerol stream to make it economically feasible. The goal is to develop a simple purification method to levels that do not inhibit the subsequent bioconversion. Then, using an appropriate microorganism, we will produce two value-added products from glycerol: poly 3-hydroxyalkanates (PHA), an ingredient in bioplastics; and succinic acid (SA), a platform chemical which serves as a starting point for a host of other chemicals. These products have been chosen because of their identified theoretical maximum yield and because of their growing demand on the marketplace over the next several years. This study has three objectives: (1) examine three different crude glycerol industrial streams to determine the best purification method to a level that will allow the microbes to grow; (2) successfully produce both PHA and SA from the resulting glycerol at high yields; and (3) study downstream processes to produce these chemicals in pure form, and integrate these processes into existing biodiesel plants. The successful completion of this research will help the biodiesel industry find new uses for its byproducts (which will increase revenues), increase production efficiency of these products, and indirectly reduce the impact of biodiesel production on the environment. Additionally, the project will produce HQP (MSc and PhD) for Canada in an interdisciplinary field.