Production of high quality biodiesel from waste feedstocks

从油炸和加工过程中获得的废油是生产生物柴油的有前途的脂质来源。然而，为了将这些废物升级为高质量的燃料，必须克服重大的技术挑战。原料污染和可变性的问题必须解决在处理废脂提供一致的产品，可以添加到柴油燃料。此外，迫切需要一种内在可靠的加工技术，以达到新的更严格的北美生物柴油标准。与加拿大生物柴油生产商的磋商显示，生物柴油纯度的新标准对废料原料的处理施加了更大的限制。渥太华大学最近开发的生物柴油膜反应器提供了一种内在可靠的处理技术来应对这些挑战。这种连续膜反应器的新特点是它能够同时将脂质原料转化为生物柴油，并将反应产物从原料中分离出来。早期的试验表明，在含有大量游离脂肪酸的油的基础酯化过程中，膜反应器能够保留肥皂。该反应器已经用食品级菜籽油进行了测试，但在很大程度上还没有使用黄油脂（用过的煎炸油）等废油进行测试。我们建议确定膜反应器中所用膜的临界通量。采用不同等级的黄油脂原料，生产出符合新标准的生物柴油。该项目旨在开发技术，利用滤过和各种离子交换树脂，减少从废油生产的生物柴油中的一价和二价盐。研究了膜孔径对膜反应器中游离脂肪酸、皂液滞留量、生物柴油的焦化性能和蒸馏温度的影响。

Waste oils obtained from frying and rendering activities are promising sources of lipids for the production of biodiesel. However, in order to upgrade these wastes to high quality fuels, significant technological challenges must be overcome. Issues of feedstock contamination and variability must be addressed in processing waste lipids to provide a consistent product that can be added to diesel fuel. There is also an urgent need for an inherently reliable processing technology that can achieve the new tighter North American biodiesel standards. Consultation with Canadian biodiesel producers has revealed that new standards on biodiesel purity are imposing greater constraints on the processing of waste feedstocks. A biodiesel membrane reactor recently developed at the University of Ottawa offers an inherently reliable processing technology to meet these challenges. The novel feature of this continuous membrane reactor is its ability to simultaneously transform lipid feedstock into biodiesel and separate the reaction products from the feedstock. Early tests point to the ability of the membrane reactor to retain soaps during the base esterification of oils containing high free fatty acids. The reactor has been tested with food-grade canola oil, but remains largely untested using waste oils such as yellow grease (used frying oils). We propose to determine the critical flux of the membranes used in the membrane reactor. Using various grades of yellow grease feedstock, we will produce biodiesel meeting the new standards. The project aims at developing technology to reduce mono and divalent salts in biodiesel produced from waste oils using diafiltration and various ion-exchange resins. The effect of membrane pore size on free fatty acids and soap retention in the membrane reactor, the coking properties and the distillation temperatures of the biodiesel produced will be determined.