STTR Phase I: Conversion of food waste to biofuels using an anaerobic membrane bioreractor

这一小型企业技术转让项目的更广泛的影响/商业潜力将是一种成本效益高、商业上可行的现场处理食物垃圾和能源回收的替代工艺。在美国，近40%的食品被浪费，相当于1650亿美元的食品损失加上相关的水、能源、化学品和用于食品生产的劳动力。食物垃圾的处理涉及额外的成本，并会造成环境污染，例如，在垃圾填埋场腐烂的食物垃圾占美国甲烷排放量的很大一部分，甲烷是一种强大的温室气体。此外，食物垃圾流含有大量的化学能量，这些能量也会在处理过程中损失。在这个项目中，以生物燃料和化学品的形式回收食物垃圾中的能量，将提供对食物垃圾问题的有效管理，在生产有用产品的同时降低食物垃圾处理成本。这个STTR第一阶段项目建议开发和展示一种基于固定化梭状芽孢杆菌细胞膜生物反应器的新的、基于连续工艺将食物垃圾转化为丁醇的性能。传统的基于搅拌槽发酵反应器的餐厨垃圾转化工艺丁醇浓度低，生产效率低。拟议的工艺将解决传统工艺的技术障碍，将梭状芽孢杆菌细胞固定在多孔介质上，以显著提高细胞培养密度，从而提高丁醇生产率和转化效率。此外，通过将丁醇从反应介质中分离出来，将反应器中回收的丁醇浓度降至最低，从而减轻了丁醇的毒性。生物质分离中的膜污染问题将通过“明渠”膜组件的设计来解决，以分离生物质并将其循环到生物反应器中。通过使用渗透汽化膜，从稀相反应器流出物中回收丁醇所需的能量将比传统蒸馏降低一个数量级。拟议工作的目标是展示一个稳定的、连续的综合过程，在优化个别成分后将食物垃圾转化为丁醇。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) project will be a cost-effective, commercially viable, alternative process for on-site treatment of food waste and energy recovery. In the U.S., nearly 40% of food is wasted with $165 billion equivalent loss of food plus associated water, energy, chemicals, and labor used in food production. Disposal of the food waste involves additional costs and causes environmental pollution, e.g. rotting food waste in landfills accounts for a large portion of U.S. methane emissions, a powerful greenhouse gas. Moreover, food waste streams contain a substantial amount of chemical energy that also is lost by its disposal. Recovering energy in food waste in the form of biofuel and chemicals, as proposed in this project, will provide efficient management of food waste problem reducing food waste disposal costs while producing useful products.This STTR Phase I project proposes to develop and demonstrate the performance of a novel, immobilized clostridia cell membrane bioreactor-based continuous process to convert food waste to butanol. The conventional stirred-tank fermentation reactor-based food waste conversion process exhibits low butanol concentration as well as productivity. The proposed process will address the technical barriers of the conventional process by immobilizing the clostridia cells on porous media to dramatically increase cell culture density, and, consequently, butanol productivity and conversion efficiency. In addition, by separating butanol from the reaction media, recycled butanol concentration is minimized in the reactor, which alleviates butanol toxicity. The membrane fouling issues in biomass separation will be addressed by an "open channel" membrane module design to separate and recycle biomass to the bioreactor. The energy requirement for recovery of butanol from dilute reactor effluent will be reduced by an order of magnitude over the conventional distillation by using a pervaporation membrane. The objective of the proposed effort is to demonstrate a steady state continuous integrated process for converting food waste to butanol after optimizing individual components.