Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “valorization”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Cobalt–niobium co-doping of indium oxide: structural and adsorption/catalytic properties for CO 2 valorization

The co-doping of the indium oxide structure with cobalt and niobium is attempted using a microemulsion method to produce high-surface-area, mesoporous, functional materials. The co-doping leads to a major nanometric bixbyite oxide phase, with both cations occupying cation positions and affecting the size and shape of the oxide entities. For specific cobalt to niobium atomic ratios, the presence of a second surface phase is encountered. Such a surface phase corresponds to an ill-defined indium hydroxide-type phase. The coexistence of the two phases is a unique phenomenon associated with the presence of both cations, which play a decisive role in promoting the CO 2 adsorption capability of the solids, as well as the valorization of the molecule under dual heat–light excitation. The co-doping of indium oxide thus appears to be a unique way to intensify the analogous thermal (classical) catalytic process for the elimination/valorization of carbon dioxide.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Valorization of consolidated bioprocessing residues for bioplastics

This study demonstrates an organic solvent-free processing strategy to valorize consolidated bioprocessing (CBP) residues, from switchgrass and poplar biomass, into functional poly(butylene succinate) (PBS)-based biocomposites using high-shear homogenization (HSH). HSH transformed the switchgrass and poplar CBP residues (CBP-R) into fine, uniformly distributed particles and microfibers. The composites of PBS with homogenized switchgrass residues (H-CBP-R-SG) or homogenized poplar residues (H-CBP-R-P) at a 70/30 weight ratio exhibited improved processability and mechanical integrity, with the Young's modulus for the PBS/H-CBP-R-SG and PBS/H-CBP-R-P nearly doubling to 0.66 ± 0.07 GPa and 0.65 ± 0.04 GPa, respectively, compared to neat PBS (0.36 ± 0.02 GPa). Dynamic Mechanical Analysis (DMA) reveals a significant suppression of the tan δ peak magnitude, indicating that HSH-mediated physical activation facilitates stress transfer in composites typical of covalent chemical grafting systems. While the transition to a stiffness-dominated profile reduces ductility, the resulting composites exhibit the dimensional stability and resistance to thermal warping required for high-fidelity FDM 3D printing and injection molding. Beyond material performance, comprehensive techno-economic analysis (TEA) and life cycle assessment (LCA) confirmed that diverting CBP residues into composite products can improve the economic viability of the biorefinery without substantially increasing biorefinery global warming potential (GWP). At a 30 wt% blend ratio, incorporating residuals into PBS yielded a minimum selling price for the composite of $\$4.07$ per kg compared to the conventional bioplastic price of $\$5.00$ per kg. This approach aligns with circular bioeconomy principles by converting waste streams into value-added products. Furthermore, this innovative strategy addresses key challenges in bioplastic development, including cost, compatibility, and performance, while simultaneously advancing waste minimization strategies for sustainable manufacturing systems.

09 BIOMASS FUELS↗
DOE OSTI2020

Complete Genome Sequences of Four Natural Pseudomonas Isolates That Catabolize a Wide Range of Aromatic Compounds Relevant to Lignin Valorization

Many soil microorganisms have evolved catabolic strategies to utilize phenolic compounds arising from depolymerized lignin. We report the complete genome sequences of four Pseudomonas sp. isolates that demonstrated robust growth on a wide range of aromatic monomers and dimers that are relevant to the valorization of lignin into value-added chemicals.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Advanced one-pot deconstruction and valorization of lignocellulosic biomass into triacetic acid lactone using Rhodosporidium toruloides

Abstract Background Rhodosporidium toruloides is capable of co-utilization of complex carbon sources and robust growth from lignocellulosic hydrolysates. This oleaginous yeast is therefore an attractive host for heterologous production of valuable bioproducts at high titers from low-cost, deconstructed biomass in an economically and environmentally sustainable manner. Here we demonstrate this by engineering R. toruloides to produce the polyketide triacetic acid lactone (TAL) directly from unfiltered hydrolysate deconstructed from biomass with minimal unit process operations. Results Introduction of the 2-pyrone synthase gene into R. toruloides enabled the organism to produce 2.4 g/L TAL from simple media or 2.0 g/L from hydrolysate produced from sorghum biomass. Both of these titers are on par with titers from other better-studied microbial hosts after they had been heavily engineered. We next demonstrate that filtered hydrolysates produced from ensiled sorghum are superior to those derived from dried sorghum for TAL production, likely due to the substantial organic acids produced during ensiling. We also demonstrate that the organic acids found in ensiled biomass can be used for direct synthesis of ionic liquids within the biomass pretreatment process, enabling consolidation of unit operations of in-situ ionic liquid synthesis, pretreatment, saccharification, and fermentation into a one-pot, separations-free process. Finally, we demonstrate this consolidation in a 2 L bioreactor using unfiltered hydrolysate, producing 3.9 g/L TAL. Conclusion Many steps involved in deconstructing biomass into fermentable substrate can be combined into a distinct operation, and directly fed to cultures of engineered R. toruloides cultures for subsequent valorization into gram per liter titers of TAL in a cost-effective manner.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

NAWI Research Spotlight: Technoeconomic Assessment of Brine Valorization from Brackish Groundwater

This NAWI Research Spotlight Webinar was presented to the NAWI Alliance on June 27, 2024. The presentation describes project progress to date on a technoeconomic assessment of brine valorization from brackish groundwater. Desalination at inland brackish groundwater treatment plants is currently limited by high costs of concentrate management and disposal. With current methods, 5-25% of the feed is disposed of as concentrate, with 98% of disposal using conventional methods (i.e. no byproduct recovery). This project aims to assess the technical and economic feasibility of industrial ecosystems to desalinate brackish groundwater and supply existing and potential markets for clean concentrate or other bulk constituents from the brine.

Fritz, Alison↗
DOE OSTI2026

Superstructure Optimization for Brine Valorization from Brackish Water Desalination

This poster presents preliminary results from a superstructure optimization framework developed to identify cost-optimal brine valorization configurations for brackish water desalination plants across diverse U.S. regional feed chemistries. The study uses brackish groundwater compositions from Arizona, California, Florida, New Mexico, and Texas. Using Pyomo Generalized Disjunctive Programming (GDP) within the WaterTAP modeling environment, the optimization framework simultaneously evaluates thousands of candidate treatment configurations, spanning nanofiltration, reverse osmosis, and chemical precipitation, to minimize the levelized cost of water (LCOW) while meeting water recovery targets and product recovery constraints. Results across eight representative feed clusters demonstrate water recovery rates of 57–87% and net LCOW values ranging from -$0.032/m³ (net revenue-positive) to $0.80/m. Notably, no single process configuration was optimal across all feed types, underscoring the necessity of feed-specific optimization. Products targeted include calcium carbonate (CaCO₃) at $0.01/kg and sodium chloride (NaCl) at $0.10/kg, both at 95% purity, with product revenues offsetting treatment costs in several scenarios. The work advances NAWI's process systems engineering capabilities for multi-configuration screening.

58 GEOSCIENCES↗
DOE OSTI2022

Editorial: Lignocellulose valorization: Fractionation, conversion and applications

Lignocellulosic biomass is the most abundant form of renewable feedstock on the Earth. Chemicals, energies, and materials derived from lignocellulosic biomass are renewable and sustainable, and have the potential to replace fossil feedstocks. Biorefinery, a process to fractionate lignocellulose into the three major components, is considered the most pivotal step for bioenergy, biomaterials and biochemicals. However, due to the complex hierarchy and chemical structures, only limited lignocellulose is valorized into value-added products, and most of them are burnt or just discarded. Therefore, there is a need to investigate the heterogeneous structure of lignocellulose, improve its efficient fractionation into cellulose, hemicelluloses and lignin, and develop the technology that can convert the lignocellulose into high-value chemical products and high-performance functional materials in a sustainable and promising configuration. In short, the ultimate goal of biomass utilization is that the production of biofuels and biomaterials in industrial applications must be cost-, and performance-competitive with petroleum-derived equivalents.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Biological Lignin Valorization

Given lignin's heterogeneity, catalytic depolymerization results in aromatic compound mixtures, and conversion of this complex substrate to a single product is challenging. To that end, the Biological Lignin Valorization (BLV) project is pursuing biological funneling, wherein aromatic catabolic microbes are engineered to convert a mixture of lignin-derived compounds to a single product. Namely, we employ Pseudomonas putida and pursue atom-efficient products, such as muconic acid, which can be further converted to direct replacements or used in performance-advantaged bioproducts. Overall, biological lignin conversion can make major contributions to reduce the minimum fuel selling price of the integrated biorefinery. Early industrial efforts in this area are also leading to value-added products, including in collaboration with the BLV project. Primary challenges associated with BLV efforts include accessing bio-available monomers from lignin (with the Lignin Utilization project), enabling commercial titers, rates, and yields of bioproducts from lignin-derived compounds, and overcoming substrate and product toxicity. To date, we have 1) demonstrated 49 g/L of muconate from aromatic compounds and 4 g/L of muconate from lignin, 2) improved the toxicity tolerance of P. putida to key aromatic substrates, 3) debottlenecked biological funneling for higher rates, and 4) engineered P. putida to convert S, G, and H-type lignin-derived compounds to a single product.

BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗
DOE OSTI2023

Optimization of C. ljungdahlii for the Valorization of Combustion Off-Gas

One of the largest problems that faces the realization of the circular economy is the gap between waste streams and usable commodities. Synthetic biology enables a toolkit where this gap can begin to be addressed and closed. This work focuses on using synthetic biology techniques to optimize C. ljungdahlii for the valorization of combustion off-gas waste streams and navigates how to produce 3-hydroxybutyrate, a polymer precursor off of similar-composition syn-gas streams. If successful, these techniques can realize a carbon-negative solution to producing plastics.

3-hydroxybutyrate↗
DOE OSTI2023

CO2 Valorization via Rewiring Carbon Metabolic Network

Energizing the world sustainably requires revolutionizing the way we harness natural resources. New renewable technologies include the microbiological upgrading of CO2, the primary greenhouse gas that causes climate change. This project aims to develop a new bioeconomy by taking up CO2 and converting it into high-value products using an autotrophic microbe. Specifically, the team constructed an acetogenic bacterium, Clostridium ljungdahlii, and developed gas fermentation processes that convert syngas (CO2/H2/CO) to the platform compound 3-hydroxybutyrate (3HB). The project has achieved several key successes, including the design and construction of 3HB genes in the gas-fermenting bacterium, the identification of a native 3HB pathway, the conversion of syngas to 3HB through strain engineering, and the improvement of the conversion through rational and iterative strain development. The optimized strain has achieved industry-relevant production rates (0.1 g/L/h) and titers (9.2 g/L), and sustained continuous gas fermentation for 3HB production for > 50 days in a bench-top gas bioreactor. The project has both industrial and scientific implications, including the exploitation of host microbes and processes to improve industrial-scale production of value-added compounds from CO2, and the promotion of gas fermentation technology. The team is also strengthening R&D synergies with other teams and industrial partners in the CO2 consortium, developing cutting-edge approaches for rapid and rational engineering of gas-fermenting hosts, and dissecting the thermodynamics and kinetics of processes for biological syngas valorization. So far, one patent application and one research article have resulted from this work, and the team anticipates additional significant outcomes from this project.

3-hydroxybutyrate↗
DOE OSTI2021

Efficient Screening of Bi–Metallic Electrocatalysts for Glycerol Valorization

Glycerol is a byproduct of biodiesel production and, as such, it is of limited economic value. By means of electrooxidation, glycerol can be used as a feedstock for scalable hydrogen production, in addition to conversion to value-added products. The development of novel and efficient catalytic electrode materials for the anodic side of the reaction is a key towards a hydrogen-based energy economy. In the present study, a computational screening protocol combining DFT, scaling relations, and microkinetic modeling allows for a rational selection of novel catalysts that can deliver efficient glycerol electrooxidation, low cost of production, and environmental sustainability. Activity and chemical selectivity towards hydrogen production on pure metal catalysts is discussed in terms of volcano-shaped plots. We find that the selectivity in the glycerol oxidation reaction is influenced by a different energy landscape when in the presence of water and best classified by a comparison of O—H and C—H bond-breaking barriers. In addition, we screened 3570 bi-metallic catalysts in the AB (L1 0 ) and A 3 B (L1 2 ) ordered structures for activity, stability, price, and toxicity. By filtering based on the criteria for toxicity, resistance to oxidation, miscibility, and price, we have identified 5 L1 0 structured catalysts (AgPd, AuPd, PtSb, CuPt, and AgPt) and 20 L1 2 catalysts (Ga 3 Ta, In 3 Ta, Ir 3 W, Ir 3 Mo, Cu 3 Pt, Ir 3 Ta, Ir 3 Re, Pd 3 Bi, Pd 3 Cu, Pd 3 W, Pd 3 Co, Pd 3 Sn, Pd 3 Mo, Pd 3 Ag, Pd 3 Ga, Pd 3 Ta, Au 3 Ru, Pd 3 In, Au 3 Ir, and Pd 3 Au) that are all predicted to show high activity. We also identify an additional 37 L1 0 and 92 L1 2 structured electrocatalysts with an anticipated medium-high activity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Valorization of Miscanthus x giganteus for sustainable recovery of anthocyanins and enhanced production of sugars

The increased awareness for eco-friendliness and sustainability has shifted the interest of stakeholders from synthetic colors to natural plant-based pigments. In this study, purple stemmed Miscanthus x giganteus was evaluated as a source of anthocyanins. Hydrothermal pretreatment was studied as a green, chemical-free process for recovering maximum anthocyanins in the pretreatment liquor. The highest recovery of 94.3 ± 1.5% w/w of the total anthocyanin concentration was obtained for a temperature and time combination of 170 °C and 10 min. The pretreatment also improved the enzymatic digestibility of the biomass and led to a 2.1-fold increase in the overall recovery of glucose (70.6 ± 0.5% w/w) at the end of 72 h. The sugar monomers obtained after the enzymatic hydrolysis of the pretreated biomass could be used for the production of biofuels or biochemicals in an integrated biorefinery based on purple-stemmed miscanthus. Altogether, this study demonstrates that the clean pretreatment method developed could lead to an additional product stream (rich in anthocyanins) along with its effect in reducing the recalcitrance of miscanthus biomass.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Paired electrocatalysis in 5-hydroxymethylfurfural valorization

5-Hydroxymethylfurfural (HMF) has aroused considerable interest over the past years as an important biomass-derived platform molecule, yielding various value-added products. The conventional HMF conversion requires noble metal catalysts and harsh operating conditions. On the other hand, the electrocatalytic conversion of HMF has been considered as an environmentally benign alternative. However, its practical application is limited by low overall energy efficiency and incomplete conversion. Paired electrolysis and highly efficient electrocatalysts are two viable strategies to address these limitations. Herein, an overview of coupled electrocatalytic HMF hydrogenation or hydrogen evolution reaction (HER) with HMF oxidation as well as the associated electrocatalysts are reviewed and discussed. In this mini-review, a brief introduction of electrocatalytic HMF upgrading is given, followed by the recent advances and challenges of paired electrolysis with an emphasis on the integration HMF electrohydrogenation with HMF electrooxidation. Finally, a perspective for a future sustainable biomass upgrading community based on electrocatalysis is proposed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗