Bio-plastics production from industrial waste streams in membrane bioreactors

由于各种原因，包括对可再生和可生物降解化学品的需求，农村经济发展，环境可持续性和废物管理，生物塑料生产取代石化基聚合物正在成为一个重要的研究和商业领域。加拿大有丰富的工业和农业废物流富含碳，这是生物聚合物合成的主要原料目标。聚羟基链烷酸酯（PHA）是一组可以通过细菌发酵生产的聚合物，具有工业和商业价值，因为它们可以取代化石燃料基聚酯，并且是可生物降解的。PHA的亚组，具有6-14个碳链长度的那些被称为中链长度PHA（mcl-PHA），由于其有利的热塑性性质而具有高的商业价值。影响PHA生产的总体经济性的最重要因素是PHA生产率（所生产的PHA质量/反应器体积/时间）和原料成本。这项研究旨在这两个方面取得重大进展。纯化学原料将被马铃薯加工厂（废油）和生物柴油生产厂（废甘油）的工业废物流所取代。我们将探索细菌发酵方法，以最大限度地从这些废物来源生产mcl-PHA。我们将确定生产的PHA的浓度和组成，并评估其潜在的商业价值。当从间歇或半间歇进料操作切换到连续进料操作时，PHAs的体积生产率可以大幅提高。我们将使用膜生物反应器（MBR）系统进行连续进料发酵，以提高容积生产率，减少生产占地面积，提供一致的产品质量，并减少生产停机时间。这将标志着MBR系统（通常用于废水处理）首次被评估用于从工业废水流中生产mcl-PHA。这项研究将支持加拿大日益增长的生物精炼工业，进一步发展现有的科学知识基础，并为工业应用提供新的替代生产系统。

Bio-plastics production to displace petrochemical based polymers is emerging as an important research and commercial area due to a variety of reasons including the need for renewable and biodegradable chemicals, rural economic development, environmental sustainability, and waste management. Canada has abundant industrial and agricultural waste streams rich in carbon, which are prime feedstock targets for bio-polymer synthesis. Polyhydroxyalkanoates (PHAs) are a group of polymers that can be produced through bacterial fermentation and are of industrial and commercial interest, as they can replace fossil-fuel based polyesters and are biodegradable. A sub-group of PHAs, those with carbon chain lengths of 6-14 termed medium chain length PHAs (mcl-PHAs) have a high commercial value due to their favorable thermoplastic properties. The most important factors affecting the overall economics of PHA production are PHA productivity (mass of PHA produced/reactor volume/time) and cost of raw materials. This research aims to make significant progress on both these fronts. Pure chemical feedstock will be replaced by industrial waste streams from potato processing (waste oils) and biodiesel production (waste glycerol) plants. We will explore bacterial fermentation methods to maximize the production of mcl-PHAs from these waste sources. We will determine the concentration and composition of the PHAs produced and assess its potential commercial value. The volumetric productivity of PHAs can be increased substantially when switching from a batch or semi-batch feed operation to a continuous-feed operation. We will use a Membrane Bioreactor (MBR) system for continuous-feed fermentation to increase volumetric productivity, decrease production footprint, provide consistent product quality, and reduce production down-time. This will mark the first time MBR systems (commonly used for waste water treatment) will be evaluated for the production of mcl-PHAs from industrial waste streams. This research will support the growing bio-refining industry in Canada, furthering the existing scientific knowledge base and providing a new alternative production system for industrial application.