Engineering topics
Publications and source records attributed to Hunter-Sellars, Elwin.
Correction for ‘Improving the direct air capture capacity of grafted amines via thermal treatment’ by Melinda L. Jue et al. , Chem. Commun. , 2024, 60 , 7077–7080, https://doi.org/10.1039/D4CC01634C.
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Elevated thermal treatments increase the CO 2 capacity of aminosilane-grafted SBA-15 sorbents through freeing up additional surface hydroxyls and favoring CO 2 binding as carbamic acid.
Our analysis shows it is feasible for the United States to remove a staggering amount of CO 2 from the air—this will be critical to becoming carbon neutral by 2050. Our comprehensive, first-of-its-kind, county-resolution analysis indicates that our country can accomplish this goal by relying on demonstrated technology, natural resources, and workforces we already have. Additionally, ongoing technology development can lower costs, shorten timelines, and deliver new solutions. Our analysis evaluated how we can use forests, cropland soils, and waste biomass, along with purpose-built machines, to get us to net-zero. Further, we considered community impacts and identified locations where certain solutions could be uniquely beneficial or potentially counterproductive. Our findings enable decisionmakers to weigh both opportunities and constraints and to decide what roads to use to meet our national climate goal for net-zero CO 2 emissions.
Combined modeling and experiments uncover the influence of epoxide-functionalization on hydrogen bonding and mobility within poly(ethylenimine) CO 2 sorbents, rationalizing the antidegradation benefits conferred by functionalization.
The diffusion processes between adsorbent and adsorbate naturally play a significant role in the efficiency and selectivity of the heterogenous catalytic process. This paper considers the importance of diffusion processes in the transfer hydrogenation reaction of levulinic acid to γ-valerolactone by MIL-88B, MIL-100, and ZIF8@Pd monolithic catalysts. Over a period of five catalytic cycles, it was shown that the Fe-based catalysts can achieve similar conversions to the ZIF-8 supported Pd, with the only current limitation being the lower aqueous stability of these MOFs. Diffusion constants were calculated using the ZLC method, with micropore diffusion limitation found for ZIF-8 and MIL-100 monolithic frameworks at 2.7 x 10 -8 and 4.6 x 10 -8 cm 2 s -1 respectively. This diffusion limitation was also confirmed by IR spectroscopy with an increasing concentration of C—H bands on the MOF substrate post-reaction. Mass transfer coefficients, also calculated by ZLC, revealed increased mass transport for the hydrophobic ZIF-8 framework, which perhaps aids in the γ-valerolactone selectivity over side products that are produced in the absence of catalytic material, as seen for MIL-88B and MIL-100 after multiple uses.