Engineering topics
Miatto, Alessio
Publications and source records attributed to Miatto, Alessio.
U.S. Cobalt: A Cycle of Diverse and Important Uses
We present a material flow and stock analysis for cobalt use and waste in the United States from 1996 to 2020, including the separation of cobalt flows into six product groups and five end-use sectors. The results demonstrate the importance of U.S. manufacturing for air travel, energy storage, cemented carbides, and numerous other applications. Battery use in the United States has become the primary factor in cobalt demand, but the batteries are manufactured mainly elsewhere. The correlation of cobalt products to principal end-use sectors provides an informed view of the location of cobalt in in-use stocks. Furthermore, two approaches could primarily address these stocks: enhanced recycling of batteries in consumer/business electronics and implementing cobalt-free substitutes for chemical uses and future battery technologies. Overall, cobalt's uses are as diverse and societally crucial as any element in the periodic table but have heretofore not received the levels of attention they deserve.
United States plastics: Large flows, short lifetimes, and negligible recycling
Given increasing concerns for the marine environment and human health, as well as trade restrictions from Asian countries, plastics have become a great challenge for the United States. This study addresses the seven commonly used plastics: low-density polyethylene/linear low-density polyethylene, high-density polyethylene, polyethylene terephthalate (PET), polypropylene, polystyrene, polyvinyl chloride, and other plastics. Material flows of the seven polymers were tracked from production into fabrication, manufacturing, flow into use, waste management, and recycling in the United States in 2015. Low- and high-density polyethylene and polypropylene were found to be the largest in both production and product manufacture. More than 88% of the plastics went into three end-use sectors: Packaging, Consumer and Institutional Products, and Building and Construction. In-use lifetimes across the plastics are generally short. Virgin plastics were mainly exported, while intermediate plastic products were largely imported. The actual end-of-life recycling rate of the plastics as a group was no more than 6.2%, with PET and the polyethylene family the most recycled. Here, the high yearly plastic throughput and low recycling rate pose a serious challenge to the sustainability goals of the United States and is in stark contrast to the vision of a circular economy of plastics.