FMSG: ECO: Towards Circular Manufacturing of Hydrocarbon Feedstocks from Plastic Waste

塑料给我们的社会带来了一个复杂的困境。我们可以高效、低成本地生产各种聚合物产品，但由此产生的废物是我们这个时代最大的环境挑战之一。这也为制造业提供了巨大的机会;每年有数百万吨减少碳的原料进入垃圾填埋场和水道。如果我们的塑料废物可以转化为更易加工的形式，如果我们能够找到足够大的市场来容纳产品材料，我们可能会释放出广泛的新制造机会。现代石化工业是为数不多的大到足以容纳我们每年的塑料废物的市场之一。 将废塑料重新整合到石化供应链中，将利用巨大的规模经济，发展循环塑料经济，同时减少我们每年的石油消耗。该项目旨在通过开发将废塑料转化为“聚原油”所需的基础化学，工程和经济学来解决这一问题，这种材料可以加入现有的石化供应链。一项补充性的技术经济分析将有助于指导该项目开发经济上可行的产品和工艺。这一影响进一步受到综合劳动力发展计划的推动，该计划旨在通过从代表性不足的群体中招募未来的科学家和工程师来扩大参与，同时提供跨学科研究和领导力培训，以确保他们在未来的制造业角色中取得成功。通过这一基础科学，我们将帮助培养广泛的未来劳动力（研究生，本科生和高中生）的技术和批判性思维技能，为21世纪世纪制造业所必需的。 这项工作旨在开发基础化学和工程，以帮助开发一个塑料制造平台，通过该平台将塑料废物转化为有价值的化学原料。其好处包括缓解对天然石化资源的需求，实现基于循环塑料经济的未来制造，以及满足关键的社会、环境和经济需求。使用聚合物熔体的催化方法受到与间歇式反应器相关的缓慢扩散和工艺效率低下的阻碍。本研究旨在阐明聚烯烃在金属氧化物催化剂上的竞争传输和尺寸选择性吸附的基本热力学因素。 使用（i）特定尺寸的聚烯烃，（ii）中子散射技术，和（iii）在流动反应器中的竞争吸附测量，我们将开发吸附模型，这将有助于我们探测深度互连的聚合物-溶剂-表面相互作用，这些相互作用控制这些系统中的竞争吸附，并驱动聚合物从溶液中吸附，以有利于长链聚合物。这将反过来用于改善催化活性和选择性，因为它将提供一种通过将聚烯烃溶解在适当的烃溶剂中并采用流动反应器研究聚烯烃从溶液吸附到催化剂表面上来绕过临界质量传递障碍的手段。同位素取代和先进的中子散射技术，以区分不同的聚合物和溶剂提供了令人信服的优势。了解这些相互关联的因素将使我们能够开发设计工艺（温度，溶剂，催化剂）所需的基础知识，这些工艺可以在塑料废物流的催化加氢裂化过程中最大限度地减少低价值产品的生产。通过控制这些参数，我们假设选择性的聚合物吸附在催化表面上可以智能地偏置控制产品分布。这一未来制造奖得到了化学、生物、环境工程和运输系统以及土木工程的共同资助，工程理事会的机械和制造创新部门以及数学和物理科学理事会的化学部门。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。

Plastics present our society with a complex dilemma. We can efficiently and inexpensively produce a fantastic array of polymer products, yet the resulting waste is one of the greatest environmental challenges of our time. It also presents an enormous opportunity for manufacturing; there are literally millions of tons of reduced carbon feedstocks going to landfills and waterways every year. If our plastic waste could be converted into a more processible form and we if we could find markets large enough to accommodate the product materials, we may unlock a wide range of new manufacturing opportunities. The modern petrochemical industry is one of the few markets large enough to accommodate our annual plastic waste. Re-integrating waste plastic into the petrochemical supply chain would take advantage of enormous economies of scale and develop a circular plastics economy while simultaneously reducing our annual petroleum consumption. This project seeks to address this problem by developing the fundamental chemistry, engineering, and economics needed to convert waste plastic into “poly-crude”, a material that can be dropped into the existing petrochemical supply chain. A complementary techno-economic analysis will help direct the project towards economically viable products and process considerations. This impact is further buoyed by an integrated workforce development plan that aims to broaden participation by recruiting future scientists and engineers from underrepresented groups, while also providing interdisciplinary research and leadership training that will ensure their success in future manufacturing roles. Through this fundamental science, we will help to train a wide range of the future workforce (graduate students, undergraduates, and high school students) in the technical and critical thinking skills necessary for 21st century manufacturing. This work seeks to develop the fundamental chemistry and engineering to help develop a plastics manufacturing platform by which plastic waste is converted to valuable chemical feedstocks. Benefits include alleviating demand on natural petrochemical resources, enabling future manufacturing based upon a circular plastics economy, and addressing critical societal, environmental, and economic needs. Catalytic methods using polymer melts are encumbered by slow diffusion and process inefficiencies associated with batch reactors. This project aims to elucidate the fundamental thermodynamic factors inherent in competitive transport and size-selective adsorption of polyolefins on metal oxide catalysts. Using (i) size-specific polyolefins, (ii) neutron scattering techniques, and (iii) competitive adsorption measurements in flow reactors, we will develop adsorption models that will help us probe the deeply interconnected polymer-solvent-surface interactions that govern competitive adsorption in these systems and drive polymer adsorption from solution to favor longer chain polymers. This will, in turn, be used to improve both catalytic activity and selectivity, as it will provide a means of getting around critical mass transport barriers by dissolving polyolefins in appropriate hydrocarbon solvents and employing flow reactors to study polyolefin adsorption onto catalyst surfaces from solution. Isotopic substitution and advanced neutron scattering techniques to distinguish between different polymers and solvents provide compelling advantages. Understanding these interrelated factors will allow us to develop the fundamental knowledge necessary to design processes (temperature, solvent, catalyst) that minimize the production of low-value products during catalytic hydrocracking of plastic waste streams. By controlling these parameters, we postulate selective polymer adsorption on a catalytic surface can be intelligently biased to control the product distribution. This Future Manufacturing award was supported by co-funding from the Chemical, Biological, Environmental Engineering and Transport Systems and the Civil, Mechanical and Manufacturing Innovation Divisions in the Directorate for Engineering and the Division of Chemistry in the Directorate for Mathematical and Physical Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.