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Results for “biomass 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.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Effect of digestate and digestate supplemented with biochar on switchgrass growth and chemical composition

Digestate, a by-product of anaerobic digestion, can be an excellent source of nutrients for bioenergy crop production, while biochar, resulting from pyrolyzing biomass, can valorize the nutrients of digestate. The objective of this study was to evaluate the nutritional value of digestate and digestate + biochar for switchgrass production. The greenhouse experiment was conducted to determine the effects of a nitrogen (N) source including 0 N (control), urea (nutrient control), sewage sludge digestate, and sewage sludge digestate + corn stover biochar on switchgrass growth and feedstock composition. Nitrogen sources were observed to significantly increase plant weight at the 32-week harvest, with weight ranging from 94.2 to 125.2 g plant -1 , depending on the N source, compared to 70.7 g plant -1 from the negative control. Moreover, switchgrass treated with digestate + biochar showed higher plant weight than samples treated only with digestate. Nitrogen application of urea, digestate, and digestate + biochar had positive effects on plant height and total leaf area in the 32-week harvests and chlorophyll content in the 8-week harvests. Feedstock quality traits including hemicellulose, cellulose, and lignin content were not affected by N sources in either the 8 or 32-week harvests with the exception of ash concentration in the 32-week harvests. Our results indicate that digestate and digestate + biochar can be a potential substitute for chemical fertilizer, resulting in increased biomass yield.

09 BIOMASS FUELS↗
DOE OSTI2023

Reductive amination cascades in cell‐free and resting whole cell formats for valorization of lignin deconstruction products

Abstract The selective introduction of amine groups within deconstruction products of lignin could provide an avenue for valorizing waste biomass while achieving a green synthesis of industrially relevant building blocks from sustainable sources. Here, we built and characterized enzyme cascades that create aldehydes and subsequently primary amines from diverse lignin‐derived carboxylic acids using a carboxylic acid reductase (CAR) and an ω‐transaminase (TA). Unlike previous studies that have paired CAR and TA enzymes, here we examine multiple homologs of each of these enzymes and a broader set of candidate substrates. In addition, we compare the performance of these systems in cell‐free and resting whole‐cell biocatalysis formats using the conversion of vanillate to vanillyl amine as model chemistry. We also demonstrate that resting whole cells can be recycled for multiple batch reactions. We used the knowledge gained from this study to produce several amines from carboxylic acid precursors using one‐pot biocatalytic reactions, several of which we report for the first time. These results expand our knowledge of these industrially relevant enzyme families to new substrates and contexts for environmentally friendly and potentially low‐cost synthesis of diverse aryl aldehydes and amines.

Biotechnology & Applied Microbiology↗
DOE OSTI2021

Toward efficient single-atom catalysts for renewable fuels and chemicals production from biomass and CO 2

Transformation of biomass and CO 2 into renewable value-added chemicals and fuels has been identified as a promising strategy to fulfill high energy demands, lower greenhouse gas emissions, and exploit under-utilized resources. Cost-effective and performance-efficient catalysts are of great importance to lowering the conversion cost of biomass and CO 2 . Significant progress has been made to advance the catalyst design for these processes, with metal catalysts playing a critical role in many involved catalytic reactions. Traditional nanoparticle-based metal catalysts still require improvement in metal utilization rates, stability, and selectivity tunability. Single-atom catalysts, which have maximum atomic efficiency and a uniform and tunable metal center, as well as an adjustable metal-support interaction, provide potential opportunities to boost catalyst efficiency and thermal stability. Their well-defined and uniform structure also provides advantages to fundamental studies for understanding of the intrinsic reaction mechanism and site requirement in biomass and CO 2 conversion. In this article, we summarize and highlight the recent advances in converting biomass and CO 2 to renewable fuels and chemicals using single-atom catalysts. We discuss the design principles of single-atom catalysts and their potential applications to biomass and CO 2 upgrading as well as the origins of catalytic activity. Moreover, we compare the catalytic efficiency of various catalysts reported thus to provide a fair assessment of these catalysts. Finally, perspectives are given on the interesting fields that may guide future studies.

09 BIOMASS FUELS↗
DOE OSTI2023

Continuous culture of anaerobic fungi enables growth and metabolic flux tuning without use of genetic tools

Anaerobic gut fungi (AGF) have potential to valorize lignocellulosic biomass owing to their diverse repertoire of carbohydrate-active enzymes (CAZymes). However, AGF metabolism is poorly understood, and no stable genetic tools are available to manipulate growth and metabolic flux to enhance production of specific targets, e.g., cells, CAZymes, or metabolites. Herein, a cost-effective, Arduino-based, continuous-flow anaerobic bioreactor with online optical density control is presented to probe metabolism and predictably tune fluxes in Caecomyces churrovis. Varying the C. churrovis turbidostat setpoint titer reliably controlled growth rate (from 0.04 to 0.20 h −1 ), metabolic flux, and production rates of acetate, formate, lactate, and ethanol. Bioreactor setpoints to maximize production of each product were identified, and all continuous production rates significantly exceed batch rates. Formate spike-ins increased lactate flux and decreased acetate, ethanol, and formate fluxes. The bioreactor and turbidostat culture schemes demonstrated here offer tools to tailor AGF fermentations to application-specific hydrolysate product profiles.

Agriculture↗
DOE OSTI2022

SynMADE: synthetic microbiota across diverse ecosystems

The last two decades have witnessed rapid advances in engineering individual microbial strains to produce biochemicals and biomaterials. Furthermore, engineering microbial consortia has been relatively slow. Using systems and synthetic biology approaches, researchers have been developing tools for engineering complex microbiota. In this article, I discuss future directions and visions regarding developing microbiota as a biomanufacturing host. Specifically, I propose that we can develop the soil microbial community itself as a huge bioreactor. Ultimately, researchers will provide a generalizable system that enables us to understand microbial consortium’s interaction and metabolism at diverse temporal and spatial scales to address global problems, including the climate crisis, food inequality, waste issue, and sustainable bioproduction.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2026

Basal Plane Doping to Activate Colloidal MoS 2 Nanosheets for Catalytic Hydrodeoxygenation of para- Cresol

The valorization of biomass into biofuels is a critical process for producing renewable fuels. Hydrodeoxygenation (HDO), particularly over doped molybdenum disulfide (MoS 2 ), a transition metal dichalcogenide (TMD) material, is a common representative catalytic reaction system for converting biomass-derived materials into useful hydrocarbons. However, the location and role of dopants, such as Co, in HDO is not fully understood. The effects of dopant location and oxidation state are often precluded by inhomogeneity in the ensemble properties of nanosheet size and dopant dispersion, as well as difficulty in observing the behavior of atomic site behavior directly. Using a colloidal approach to synthesize cobalt-doped MoS 2 nanosheets with controlled dopant concentration, combined with X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations, we determine that basal plane doped Co (25% Co:Mo mole ratio) shows peak catalytic activity in HDO of para-cresol, a model biomass-derived compound, and that basal Co sites are demonstrably more active than edge sites. By observing these doping effects in MoS 2 catalysts for HDO, we can further optimize not only the production of carbon-neutral fuels but also direct the tailoring of doped TMD catalysts toward their intended applications.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Economic and environmental sustainability of bio-based HMF production and recovery from lignocellulosic biomass

5-Hydroxymethyl furfurals (HMF) is one of the versatile platform chemicals. However, green routes to produce it directly from lignocellulosic biomass are lacking. A significant amount of HMF produced during the hydrothermal valorization of lignocellulosic biomass is considered undesired and ends up in a waste stream. The study transformed the undesired byproduct into a valuable coproduct by advancing the existing biofuel production process. A detailed economic and environmental sustainability analysis of the integrated biorefinery design was performed. The evaluation showed that the biorefinery could afford a maximum feedstock purchasing price of $\$115.17$ per MT and produce HMF with a minimum selling price of $\$4.54$ per kg which is ~75% lower than the commercial price of HMF. The median global warming potential of HMF was estimated to be 3.92 kg CO 2 -eq. per kg HMF which was ~32% less than its counterpart bio-based p-xylene. Diverse coproducts produced in the biorefinery using transgenic feedstock positively impacted sustainability.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

yuyao-jia/Bio-based_HMF_coproduction

5-Hydroxymethyl furfurals (HMF) is one of the versatile platform chemicals. However, green routes to produce it directly from lignocellulosic biomass are lacking. A significant amount of HMF produced during the hydrothermal valorization of lignocellulosic biomass is considered undesired and ends up in a waste stream. The study transformed the undesired byproduct into a valuable coproduct by advancing the existing biofuel production process. A detailed economic and environmental sustainability analysis of the integrated biorefinery design was performed. The evaluation showed that the biorefinery could afford a maximum feedstock purchasing price of $115.17 per MT and produce HMF with a minimum selling price of $4.54 per kg which is ∼75% lower than the commercial price of HMF. The median global warming potential of HMF was estimated to be 3.92 kg CO2-eq. per kg HMF which was ∼32% less than its counterpart bio-based p-xylene. Diverse coproducts produced in the biorefinery using transgenic feedstock positively impacted sustainability.

Jia, Yuyao↗
DOE OSTI2020

The critical role of lignin in lignocellulosic biomass conversion and recent pretreatment strategies: A comprehensive review

Heterogeneity and rigidity of lignocellulose causing resistance to its deconstruction have provided technical and economic challenges in the current biomass conversion processes. Lignin has been considered as a crucial recalcitrance component in biomass utilization. An in-depth understanding of lignin properties and their influences on biomass conversion can provide clues to improve biomass utilization. Also, utilization of lignin can significantly increase the economic viability of biorefinery. Recent lignin-targeting pretreatments have aimed not only to overcome recalcitrance for biomass conversion but also to selectively fractionate lignin for lignin valorization. Numerous studies have been conducted in biomass characteristics and conversion technologies, and the role of lignin is critical for lignin valorization and biomass pretreatment development. In this review, we provide a comprehensive review of lignin-related biomass characteristics, the impact of lignin on the biological conversion of biomass, and recent lignin-targeting pretreatment strategies. The desired lignin properties in biorefinery and future pretreatment directions are also discussed.

09 BIOMASS FUELS↗
DOE OSTI2022

Muconic Acid Production from P. putida Using High Protein Algae Hydrolysate

The composition of algal biomass is highly dynamic, with protein, lipid, and carbohydrate contents varying in response to nutrient and environmental conditions during cultivation. Because shifts in biomass composition are often associated with reduced biomass productivity, production costs can often increase if targeting higher biomass compositional quality (enriched in carbohydrates or lipids at reduced protein content) as input for the algal biorefinery. The optimal algal biorefinery configuration is thus a function of many factors. One of the key strengths of the Combined Algal Processing (CAP) process is the versatility of feedstocks and products produced. The concept has been demonstrated with ethanol and a variety of carboxylic acids (succinic, butyric, muconic) as coproducts along with lipid upgrading to biofuel. Modification of the approaches, processes and downstream upgrading to fuels has allowed the CAP process to reduce costs and improve efficiency. Muconic acid is a high-value, potential fermentation coproduct of interest because it can be easily converted to adipic acid, a high-volume monomer for the production of nylon and other valuable consumer plastics. As such, the production of muconic acid through CAP was explored to expand the suite of products from algal biomass and to begin exploring the valorization of high protein content biomass from rapidly grown algae biomass. We have established initial performance parameters and shown that the range of substrates consumed by the muconic acid-producing microbe, Pseudomonas putida, includes at least glucose, mannose, glycerol, and lactic acid. We achieved complete utilization of these four major hydrolysate substrates achieving productivities of 0.037 (g/L/h) from Scenedesmus obliquus and 0.029 (g/L/h) from Monoraphidium minutum hydrolysates. Final titer and process yield (mol of muconic acid per mol of substrate (molP/molS)) were 0.99 g/L and 0.42 molP/molS from S. obliquus hydrolysate and 0.75 g/L and 0.23 molP/molS from M. minutum hydrolysate, respectively.

BIOMASS FUELS↗
DOE OSTI2022

Plasma technology for lignocellulosic biomass conversion toward an electrified biorefinery

Lignocellulosic biomass conversion to renewable, carbon-neutral materials, fuels, and chemicals is the cornerstone of the transition to a sustainable future bioeconomy. Green energy in the form of electricity needs to be coupled with or substitute conventional thermally driven processes to realize small-scale, economically viable and environmentally friendly biorefineries. Gas discharge plasmas enable the conversion of renewable electric energy, supplied in the form of an electric field, to chemical energy through the formation of a highly reactive environment that can induce several transformations related to agricultural waste valorization processes. Herein, we review the application of plasma technology to lignocellulosic biomass upgrade, aiming to provide the scientific background and technical challenges in this rapidly emerging research field. To bridge the gap between plasma science and biomass valorization technologies, we initially present the technical aspects of plasma reactors related to biomass processing and further discuss the advances in plasma processing for each biomass conversion technology, providing insights into the related plasma chemistry and interaction mechanisms. Here, we first focus on the low and medium-temperature biomass conversion processes, including biomass pretreatment and delignification to promote enzyme or acid-catalyzed hydrolysis to sugars and biomass liquefaction using plasma electrolysis. Then we discuss the high and very high-temperature conversion processes, such as plasma-assisted pyrolysis and gasification to syngas and plasma application to tar removal, combustion, and vitrification. Overall, this review provides knowledge at the interface of plasma science and biomass conversion technology to promote the interaction between the individual communities, which is crucial for the further advancement of the field.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Simultaneous carbon catabolite repression governs sugar and aromatic co-utilization in Pseudomonas putida M2

ABSTRACT Pseudomonas putida have emerged as promising biocatalysts for the conversion of sugars and aromatic compounds obtained from lignocellulosic biomass. Understanding the role of carbon catabolite repression (CCR) in these strains is critical to optimize biomass conversion to fuels and chemicals. The CCR functioning in P. putida M2, a strain capable of consuming both hexose and pentose sugars as well as aromatic compounds, was investigated by cultivation experiments, proteomics, and CRISPRi-based gene repression. Strain M2 co-utilized sugars and aromatic compounds simultaneously; however, during cultivation with glucose and aromatic compounds ( p- coumarate and ferulate) mixture, intermediates (4-hydroxybenzoate and vanillate) accumulated, and substrate consumption was incomplete. In contrast, xylose-aromatic consumption resulted in transient intermediate accumulation and complete aromatic consumption, while xylose was incompletely consumed. Proteomics analysis revealed that glucose exerted stronger repression than xylose on the aromatic catabolic proteins. Key glucose (Eda) and xylose (XylX) catabolic proteins were also identified at lower abundance during cultivation with aromatic compounds implying simultaneous catabolite repression by sugars and aromatic compounds. Reduction of crc expression via CRISPRi led to faster growth and glucose and p -coumarate uptake in the CRISPRi strains compared to the control, while no difference was observed on xylose+ p -coumarate. The increased abundances of Eda and amino acid biosynthesis proteins in the CRISPRi strain further supported these observations. Lastly, small RNAs (sRNAs) sequencing results showed that CrcY and CrcZ homologues levels in M2, previously identified in P. putida strains, were lower under strong CCR (glucose+ p -coumarate) condition compared to when repression was absent ( p -coumarate or glucose only). IMPORTANCE A newly isolated Pseudomonas putida strain, P. putida M2, can utilize both hexose and pentose sugars as well as aromatic compounds making it a promising host for the valorization of lignocellulosic biomass. Pseudomonads have developed a regulatory strategy, carbon catabolite repression, to control the assimilation of carbon sources in the environment. Carbon catabolite repression may impede the simultaneous and complete metabolism of sugars and aromatic compounds present in lignocellulosic biomass and hinder the development of an efficient industrial biocatalyst. This study provides insight into the cellular physiology and proteome during mixed-substrate utilization in P. putida M2. The phenotypic and proteomics results demonstrated simultaneous catabolite repression in the sugar-aromatic mixtures, while the CRISPRi and sRNA sequencing demonstrated the potential role of the crc gene and small RNAs in carbon catabolite repression.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Rapid Biocatalytic Synthesis of Aromatic Acid CoA Thioesters by Using Microbial Aromatic Acid CoA Ligases

Abstract Chemically labile ester linkages can be introduced into lignin by incorporation of monolignol conjugates, which are synthesized in planta by acyltransferases that use a coenzyme A (CoA) thioester donor and a nucleophilic monolignol alcohol acceptor. The presence of these esters facilitates processing and aids in the valorization of renewable biomass feedstocks. However, the effectiveness of this strategy is potentially limited by the low steady‐state levels of aromatic acid thioester donors in plants. As part of an effort to overcome this, aromatic acid CoA ligases involved in microbial aromatic degradation were identified and screened against a broad panel of substituted cinnamic and benzoic acids involved in plant lignification. Functional fingerprinting of this ligase library identified four robust, highly active enzymes capable of facile, rapid, and high‐yield synthesis of aromatic acid CoA thioesters under mild aqueous reaction conditions mimicking in planta activity.

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

Multi-pass flow-through reductive catalytic fractionation

Reductive catalytic fractionation (RCF) is a promising lignin-first biorefining strategy that selectively extracts and depolymerizes lignin from whole biomass. Flow-through (FT)-RCF enables physical separation of the biomass and catalyst, but this process configuration typically operates at high solvent-to-biomass ratios. Here, we demonstrate multi-pass FT-RCF, wherein the lignin-enriched solvent obtained after an initial FT-RCF step is recycled and used in subsequent FT-RCF without intermediate lignin recovery. Multi-pass FT-RCF reduces the solvent-to-biomass ratio from 48 to 1.9 L/kg, which is a lower solvent loading than is accessible in batch reactors, without negative impacts on delignification and monomer yield with up to 12 wt % lignin in the solvent. Overall, this work demonstrates that solvent demand in RCF processes, which is a key cost and energy driver to enable this process at scale, can be reduced by recycling lignin oil between RCF reactions.

09 BIOMASS FUELS↗
DOE OSTI2025

Synthesis of Solid-Solution Mn x Zn 1– x O Nanoparticles and their Electrochemical Oxidation of Furfural

Electrochemical valorization of biomass-derived substrates has become a prominent area of research due to its potential to produce value-added products from renewable feedstocks in a more sustainable way. First-row transition metal electrodes are compelling candidates for these conversions due to their stability, abundance, and cost-effectiveness. Herein, we report on the colloidal synthesis of Mn x Zn 1– x O (x = 0.3-0.7) nanoparticles and their electrocatalytic activity towards furfural oxidation. We find that the hindrance of a MnO impurity can be achieved by leveraging the oxidation state of the Mn precursor. The Mn x Zn 1– x O composition closely follows the ratio of precursors, with all the nanoparticles having a wurtzite structure as determined by ICP-MS and PXRD, respectively. XANES and XPS revealed the presence of Mn in different oxidation states with the ratio of these varying based on the composition. When comparing the electrocatalytic activity of the monometallic and bimetallic oxides for furfural oxidation, a decrease in current density was observed with increasing Zn content. We find the Mn x Zn 1– x O nanoparticles favor the formation of the 6 e - oxidation product 5-hydroxy-2(5H)-furanone, while both monometallic oxides primarily yield CO 2 and other deeply oxidized products as the majority pathway. Furthermore, these findings can contribute towards the design and synthesis of more active and selective electrocatalyst.

Aldehydes↗