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Chementator Briefs

| By Dorothy Lozowski

Tire recycling

The Mitsubishi Chemical Group (MCG; Tokyo, Japan; www.mcgc.com) has demonstrated chemical recycling of end-of-life tires (ELTs) using the coke ovens at its Kagawa Plant (Sakaide City, Kagawa Prefecture). The company is able to feed crushed ELTs as raw material into its coke ovens and produce carbon black again from the tar. According to MCG, this is the first attempt in the world to produce sustainable carbon black from ELTs using coke ovens. The sustainable carbon black produced is said to have the same performance as conventional carbon black and therefore can be used again in new tires. MCG aims to begin marketing sustainable carbon black made from ELTs by March 2026.

Solid-state battery advances

Researchers led by the Department of Energy’s Oak Ridge National Laboratory (ORNL; www.ornl.gov) have advanced the development of solid-state batteries by optimizing a polymer binder to make a strong, thin film for use with sulfide solid-state electrolytes. The researchers successfully made a flexible, solid-state electrolyte sheet that “could at least double energy storage to 500 watt-hours per kilogram,” according to ORNL’s Guang Yang. Currently available batteries that use liquid electrolytes are associated with safety concerns due to their flammability, thermal instability and potential leakage. The new sheets may allow production of safer, solid-state batteries. They would separate negative and positive electrodes and prevent dangerous electrical shorts while providing high-conduction paths for ion movement.

Plastic polymers currently used in solid-state electrolytes have much lower conductivity than liquid electrolytes. Sulfide solid-state electrolytes offer an ionic conductivity that is comparable to liquid electrolytes currently used in lithium-ion batteries. The goal of the current study was to find a film that was thin enough for ion conduction and thick enough for structural strength. The work was published in a recent issue of ACS Energy Letters.

 

Iron in catalysts

In a recent analysis of spent catalyst material from fluid catalytic cracking (FCC) units, WR Grace (Columbia, Md.; www.grace.com) found higher levels of iron species as refiners increase the amount of “opportunity” feedstocks they process. Many of these opportunity crudes, such as oil from shale, are laden with iron, which can poison FCC catalysts and reduce performance. Now, Grace is developing a host of catalyst technologies designed to mitigate the harmful effects of iron contaminants and maximize production value for refiners.

Researchers at Grace developed the iron deactivation protocol (Grace-IDP), a method for simulating the deactivation of catalyst material by iron in a laboratory setting. Under FCC reaction conditions, iron, along with other impurities, can form an amorphous silica-alumina phase at the surface of zeolite catalyst particles. The destruction of zeolite at the surface reduces catalyst performance and decreases the unit’s yield.

Leveraging information from the IDP, the Grace team addressed iron poisoning in three ways. In one, known as Grace MILLE technology, an extra step in the manufacturing process introduces more macroporosity into the catalyst materials. This optimizes pore size distribution, which helps improve vaporization of the feed molecules and aids diffusion of feed and products. Also, Grace developed novel passivation treatments for the surface of the catalyst material. Finally, the IDP helped catalyst design of existing Grace catalysts to maximize catalyst matrix surface area. ❐