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Electrification to reduce or eliminate greenhouse gas emissions is essential to mitigate climate change. However, a substantial portion of our manufacturing and transportation infrastructure will be difficult to electrify and/or will continue to use carbon as a key component, including areas in aviation, heavy-duty and marine transportation, and the chemical industry. In this Roadmap, we explore how multidisciplinary approaches will enable us to close the carbon cycle and create a circular economy by defossilizing these difficult-to-electrify areas and those that will continue to need carbon. We discuss two approaches for this: developing carbon alternatives and improving our ability to reuse carbon, enabled by separations. Furthermore, we posit that co-design and use-driven fundamental science are essential to reach aggressive greenhouse gas reduction targets.

The production of aromatic hydrocarbons from cellulose by zeolite-catalyzed fast pyrolysis involves a complex reaction network sensitive to the zeolite structure, crystallinity, elemental composition, porosity, and acidity. The interplay of these parameters under the reaction conditions represents a major roadblock that has hampered significant improvement in catalyst design for over a decade. Here, we studied commercial and laboratory-synthesized ZSM-5 zeolites and combined data from 10 complementary characterization techniques in an attempt to identify parameters common to high-performance catalysts. Crystallinity and framework aluminum site accessibility were found to be critical to achieve high aromatic yields. These findings enabled us to synthesize a ZSM-5 catalyst with enhanced activity, which offers the highest aromatic hydrocarbon yield reported to date.

This article charts the progress of CenUSA Bioenergy, a USDA-NIFA-AFRI coordinated agricultural project focused on the North Central region of the US. CenUSA’s vision is to develop a regional system for producing fuels and other products from perennial grass crops grown on marginally productive land or land that is otherwise unsuitable for annual cropping. This article focuses on contributions CenUSA has made to nine primary systems needed to make this vision a reality: feedstock improvement; feedstock production on marginal land; feedstock logistics; modeling system performance; feedstock conversion into biofuels and other products; marketing; health and safety; education; and outreach. The final section, Future Perspectives, sets forth a roadmap of additional research, technology development and education required to realize commercialization.

This study investigated the influence of alkali and alkaline earth metals (AAEM) and the role of acid pretreatments in the production of sugars during solvent liquefaction of lignocellulosic biomass using 1,4-dioxane and water as solvents. The present study found that removal of AAEM by acid washing/water rinsing did not enhance sugar production during solvent liquefaction of pretreated switchgrass nearly to the extent observed for fast pyrolysis nor did it inhibit lignin decomposition, suggesting that AAEM play less of a role in determining product yields in solvent liquefaction. On the other hand, acid infusion greatly enhanced the yields of sugars during solvent liquefaction, presumably because the strong acid catalytically promoted both the depolymerization and the dehydration of polysaccharides. The main monomeric sugars formed were levoglucosan, glucose, and xylose. Levoglucosan was the predominant sugar when 1,4-dioxane was the solvent, whereas glucose was the major sugar when water was the solvent. When 1,4-dioxane and water were cosolvents, partial hydrolysis of levoglucosan to glucose was observed. The maximum yield of the total sugars (19.8 wt %) from AI switchgrass occurred when 9:1 mixtures of 1,4-dioxane and water were used as cosolvents. In addition, the sugars were more stable in the 1,4-dioxane and water mixture compared to water alone.

Solid boron has long been recognized as a potential high volumetric density propellant for volume limited air breathing propulsion systems. However, achieving this potential has proved difficult due to low combustion and heat release efficiencies encountered when solid boron slurries are added to conventionally designed combustors. The combustion of solid boron particles with an oxygen based oxidizer has long been known to be a complex process involving both heterogeneous (gas/solid) and homogeneous (gas/gas) chemical kinetics. The difficulties in achieving the anticipated potential of boron assisted propellants in practical applications has created a need for improved understanding of the basic chemical and physical processes in these systems.

A trajectory computation program is described for determining vehicle performance throughout the entire flight regime of speed and altitude in the atmosphere and gravity field of a nonspherical rotating planet. The program is formulated for seven options of varying refinement from the six-degree-of- freedom problem to the two-degree point mass problem. A reverse option for the aerodynamic analysis of flight test data, a punched card output, and a semiautomatic computational tie to an interplanetary trajectory computer program are included. The program is specifically oriented for computation on the IBM 7090/7094 digital computer using the FAP/FORTRAN2 machine language., Report on Flight Path Analysis.

A study was made to relate theoretically predicted and experimentally observed pressure-coupled combustion instability behavior of solid propellants. Using a generalized theoretical model which incorporates both surface and gas phase combustion effects, the linear and nonlinear (higher pressure amplitude) region has been characterized by a group of combustion parameters. Concurrent experimental studies were directed toward investigating (1) the effects of coating the solid oxidizer crystals, (2) the chemical and physical nature of the propellant binder, catalysts, and crosslinking agents on the acoustic admittance, (3) nonlinear response properties, and (4) propellant burning rate. The data show that small changes in propellant formulations can have a significant effect on the derived parameters characterizing the surface and, therefore, on relative contributions of these reactions to the acoustical response properties.

Factors Influencing Student College Choice Between In-State and Out-of-State Students

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Factors Influencing Student College Choice Between In-State and Out-of-State Students

Factors Influencing Student College Choice Between In-State and Out-of-State Students