METHOD OF COMBINED SEPARATION AND CONVERSION OF AN OXYGENATE AND MICROCHANNEL REACTIVE DISTILLATION APPARATUS (iEdison No. 0685901-20-0041)
Here we demonstrate the proof-of-concept for microchannel reactive distillation for alcohol-to-jet application: combining ethanol/water separation and ethanol dehydration in one unit operation. Ethanol is first distilled into the vapor phase, converted to ethylene and water, and then the water co-product is condensed to the shift reaction equilibrium. Process intensification is achieved through rapid mass transfer - ethanol stripping from thin wicks using novel microchannel architectures - leading to lower residence time and improved separation efficiency. Energy savings are realized with integration of unit operations. For example, heat of condensing water can offset vaporizing ethanol. Furthermore, the dehydration reaction equilibrium shifts towards completion by immediate removal of the water byproduct upon formation while maintaining aqueous feedstock in the condensed phase. Conversion of 40% ethanol in water to ethylene was demonstrated with 91% ethylene selectivity and 71% ethanol conversion at 220oC, 600 psig, and 0.28 hr-1. Almost three stages of separation (2.7) were also demonstrated, under these conditions, using a device length of 9.1 cm. This provides a height equivalent of a theoretical plate (HETP), a measure of separation efficiency, of ~ 3.3. By comparison, conventional distillation packing provides an HETP of ~ 30 cm. Thus, 9X reduction in HETP was demonstrated over conventional technology, providing a means for significant energy savings.
SELECTIVE RECOVERY OF RARE EARTH ELEMENTS FROM PERMANENT MAGNETS BY ELECTROCHEMICAL LEACHING AND ELECTRODEPOSITION (iEdison No. 0685901-22-0028)
Rare earth elements (REEs) are the 15 metals in the lanthanide series of the periodic table. They have very similar properties and are often found together in geologic deposits. Most of the REE today are produced outside the United States ( > 80% being produced in China) and given that they are a key component in permanent magnets (PMs) used in clean energy technologies such as wind turbines, hybrid and electric vehicles, and other electromagnetic-to-mechanical conversion systems, as well as an essential component for optical drives and smartphones, they are deemed critical elements. As we work to rapidly transition to clean energy technologies, there is need for building a reliable domestic REE supply. One approach to sustainably increasing REE supply is through recycling of spent PMs. Existing methods for recycling magnets rely on pyrometallurgical or hydrometallurgical methods which need energy-intensive pretreatments or significant amounts of acid and chemical inputs—making them not sustainable. In contrast we report a promising new electrochemical method that is performed at room-temperature and without need for corrosives and can selectively recover REE from used PMs. We demonstrate the approach using a commercial neodymium-iron-boron (NdFeB) permanent magnet—one of the most widely used variety of magnets. We show selective Nd recovery, but the approach is also relevant to selective recovery of other REEs used in PMs. Our method involves selective electrochemical leaching of Nd from NdFeB permanent magnet followed by subsequent Nd electrodeposition on an electrode. Both steps are conducted using commercial organic electrolytes (Dimethylformamide, DMF) to ensure process scalability. We conducted experiments using commercial magnets to ensure results are transferable to industry. There are very few reported electrochemical methods for recycling, and they are all limited to aqueous acid based electrolytes—clearly distinguishing our work.
THERMOCATALYTIC DECOMPOSITION OF METHANE USING CATALYST SYSTEM DESIGN AND OPERATIONAL PARAMETERS TO CONTROL PRODUCT YIELD AND PROPERTIES (iEdison No. 0685901-22-0030)
Here we detail a new invention for how a bimetallic Ni-Cu-CNT-catalyst can be optimally designed for thermocatalytic decomposition (TCD) of methane. Specifically, we describe how the tuning of i) Ni/Cu ratio, ii) metal particle size, and iii) operating temperature are key factors in influencing TCD activity, stability, and carbon coproduct morphology. We believe these two findings are potentially patentable features: 1. Catalyst deactivation is associated with metal particle sintering, increased Ni/Cu ratio, and choice of operating temperature. For example, a monometallic Ni/CNT catalyst quickly deactivates at operating temperatures > 550 degrees C. Increasing amount of Cu addition to the Ni catalysts results in decreasing initial TCD activity, however, increasing catalyst stability (see Figure 1 in attached paper). Additionally, catalyst stability at increased operating temperatures ( > 650 degrees C) is facilitated by Ni catalysts only with high Cu loadings. It is the optimization of metal particle size, Ni/Cu ratio, and operating temperature as key parameters that together influence performance for methane TCD. 2. Carbon co-product quality can be tuned through choice of Ni/Cu ratio and operating temperature. The carbon co-product is mainly composed of multiwalled carbon nanotube (MWCNTs). While Cu addition to Ni increases catalyst stability, it also diminishes the "quality" of the CNT product as determined by Raman spectroscopy However, only relatively small amounts of Cu addition is required to provide marked improvement to stability (see Figure 9 in the attached paper). Further, as the choice in operating temperature plays a key role in dictating catalyst stability, it also influences the resulting carbon quality. Taken together, a trade off in catalyst stability and quality of the carbon product can be made. This optimization would be dictated by the process economics and carbon co--product requirements for the end use application.
SAFE AND LOW TEMPERATURE THERMITE REACTION SYSTEMS AND METHOD TO FORM POROUS SILICON
Embodiments of a safe, low-temperature reaction system and method for preparing porous silicon are disclosed. The porous silicon is prepared from porous silica, a low-melting metal halide, and a metal comprising aluminum, magnesium, or a combination thereof. Advantageously, embodiments of the disclosed methods can be performed at temperatures 400° C. Silicon produced by the disclosed methods has a porosity that is equal to or greater than the porous silica precursor. The porous silicon is suitable for use in electrodes.
SOLID-STATE RECHARGEABLE MAGNESIUM BATTERY
Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency ≧95% and exhibit cycling stability for at least 50 cycles.
Nanocomposite of graphene and metal oxide materials
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C
Thick Electrodes Including Nanoparticles Having Electroactive Materials and Methods of Making Same
Electrodes having nanostructure and/or utilizing nanoparticles of active materials and having high mass loadings of the active materials can be made to be physically robust and free of cracks and pinholes. The electrodes include nanoparticles having electroactive material, which nanoparticles are aggregated with carbon into larger secondary particles. The secondary particles can be bound with a binder to form the electrode.