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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Chapter Four—MSW characterization and preprocessing for biofuels and bioproducts

The organic fraction of MSW (OFMSW) has a high carbohydrate and lipid content, indicating its good potential as a feedstock for bioethanol and biodiesel production. However, variability in feedstock composition for MSW is a critical challenge for downstream conversion processes such as pyrolysis, gasification, incineration, and biotechnological conversion. MSW characterization is critical to inform and optimize the design of physical handling processes to minimize costs and environmental impacts, and improve the downstream conversion performance of MSW materials. Here, this book chapter focuses on current MSW characterization and preprocessing technologies and discusses the costs, benefits, and environmental impacts associated with MSW preprocessing. Also, the book chapter outlines the potential strategies to increase total revenue and mitigate negative environmental impacts for MSW recycling systems.

09 BIOMASS FUELS↗
DOE OSTI2020

Coal direct chemical looping process: 250 kW pilot-scale testing for power generation and carbon capture

Chemical looping combustion (CLC) is an energy conversion technology that can produce concentrated CO 2 stream without the need for a gas separation step, and thus, has the potential to drastically reduce the energy consumption and cost associated with CO 2 capture in power generation. The coal-direct chemical looping (CDCL) process is a CLC technology that uses a moving bed reducer configuration that can directly consume coal as a feedstock without requiring an upstream gasification step. An integrated 250 kW th CDCL pilot unit using iron-based oxygen carriers was constructed and demonstrated for over 1000 h of testing. The principles for the CDCL pilot unit design and operation are summarized in this article. During the 288-hour continuous operation testing, the CDCL pilot unit achieved >96% coal conversion with a CO 2 purity of >97%. Low carbon carryover into the combustor, i.e. <2%, was also confirmed during the test, which shows the capability of the moving bed reactor to retain and convert coal using the oxygen available on the iron-based oxygen carrier. The results from the pilot unit testing confirms the CDCL concept as a promising coal combustion technology for heat and power generation with CO 2 capture.

10 SYNTHETIC FUELS↗
DOE OSTI2021

Plastic waste upcycling toward a circular economy

Large amounts of plastics are discarded worldwide each year, leading to a significant mass of waste in landfills and pollution to soil, air, and waterways. Upcycling is an efficient way to transform plastic waste into high-value products and can significantly lessen the environmental impact of plastic production/consumption. In this article, current advances and future directions in plastic waste upcycling technologies are discussed. In particular, this review focuses on the production of high-value materials from plastic waste conversion methods, including pyrolysis, gasification, photoreforming, and mechanical reprocessing. Plastic waste compositions, conversion products, reaction mechanisms, catalyst selection, conversion efficiencies, polymer design, and polymer modification are also explored. Furthermore, the main challenges facing the adoption and scale-up of these technologies are highlighted. Suggestions are given for focusing future research and development to increase the efficiency of upcycling practices.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Water-gas shift reaction in ceramic-carbonate dual-phase membrane reactor at high temperatures and pressures

Water-gas-shift (WGS) reaction is a critical step in integrated gasification combined cycles (IGCC) power plants with CO 2 capture. Membrane reactors made with a CO 2 -permselective ceramic-carbonate dual-phase (CCDP) membrane offers the potential to enhance hydrogen yield with simultaneous CO 2 capture for WGS reaction. The present work studies operation of WGS reaction in a tubular membrane reactor made of samarium-doped ceria infiltrated with lithium/sodium molten carbonate mixture. The WGS reaction was performed in the membrane reactor with and without a high-temperature WGS catalyst at 800–850 °C, feed pressure of 7 bar, the space velocity of 150–3000 h –1 , and a feed gas mixture of 45.7/13.1/41.3 mol% CO/CO 2 /N 2 with steam to carbon ratio of 4. The results show that the catalyst-free membrane reactor can convert 92% of carbon monoxide into CO 2 and H 2 and recover 29% CO 2 at 850 °C and a space velocity of 150 h –1 . However, in the catalyst-free membrane reactor, a significant amount of unwanted carbon deposition is observed. The side reactions can be minimized by reducing the operating pressure and increasing the operating temperature and space velocity, and completely avoided using a high-temperature catalyst at space velocity>500 h –1 . The membrane reactor with a WGS catalyst achieves CO conversion of about 85%, above the equilibrium conversion, and 40% CO 2 recovery without carbon deposition at high temperature and pressure. Finally, the membrane remains in the same structure and gas-tightness after the WGS reaction tests.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2023

Prospects for engineering Ralstonia eutropha and Zymomonas mobilis for the autotrophic production of 2,3-butanediol from CO 2 and H 2

The decarbonization of the chemical industry and a shift toward circular economies because of high global CO 2 emissions make CO 2 an attractive feedstock for manufacturing chemicals. Moreover, H 2 is a low-cost and carbon-free reductant because technologies such as solar-driven electrolysis and supercritical water (scH 2 O) gasification enable sustainable production of molecular hydrogen (H 2 ). We review the recent advances in engineering Ralstonia eutropha, the representative species of "Knallgas" bacteria, for utilizing CO 2 and H 2 to autotrophically produce 2,3-butanediol (2,3-BDO). This assessment is focused on state-of-the-art approaches for splitting H 2 to supply energy in the form of ATP and NADH to power cellular reactions and employing the Calvin-Benson-Bassham cycle for CO 2 fixation. Major challenges and opportunities for application and future perspectives are discussed in the context of developing other promising CO 2 and H 2 -utilizing microorganisms, exemplified by Zymomonas mobilis.

42 ENGINEERING↗
DOE OSTI2020

Effects of blending C3-C4 alcohols on motor gasoline properties and performance of spark ignition engines: A review

Supplementing petroleum fuels with sustainable and renewable alternatives is a good option for increasing the sustainability of transportation fuels. Alcohols are particularly attractive blendstocks for spark ignition engines, mainly due to their desirable fuel properties including high octane, evaporative cooling, and reduced sooting propensity. Although the use of SI engines is widespread around the world, predominately for light duty vehicles, concerns about CO2 emissions and other sustainability issues necessitate increased engine efficiencies, reduced tailpipe pollutants, and lower lifecycle carbon emissions. The intelligent blending of C2-C4 alcohols into motor gasoline is a viable method for achieving these goals. There are a multitude of ways to produce renewable alcohols such as through fermentation from first-generation feedstocks (sugar and corn) and second-generation feedstocks (lignocellulosic biomass), or by gasification and mixed alcohol fuel synthesis routes from lignocellulosic biomass. Currently ethanol is extensively used in motor gasoline fuels worldwide and although many have proposed the use of C3 and C4 alcohols in motor gasoline as an improvement over ethanol, the higher cost of production and lack of clear definition as to their benefit over ethanol when blended into motor gasoline have led to slow acceptance into the market. In this review, special emphasis is placed on the effects of blending C3 and C4 alcohols into motor gasoline in terms of physicochemical properties, volatility behavior, and engine performance when compared to ethanol blends. Furthermore, the impact of blending C3 and C4 alcohols with gasoline on emission (particulate matter, nitrogen oxides, carbon monoxide, hydrocarbons, and unregulated oxygenates) and combustion (volumetric efficiency, thermal efficiency, fuel consumption, and cold performance) characteristics is discussed. Although there are some disagreements in the literature over the effect of alcohols predominately around the type of SI engine, i.e., port fuel injected versus direct fuel injected and engine operating mode, generally it is stated that alcohols can potentially reduce soot, unburned hydrocarbons and CO emissions while increasing thermal efficiency when proper engine configuration/calibration is used. Lastly, research that must be conducted to find the optimum combination of alcohol blends and engine configurations is highlighted and discussed.

09 BIOMASS FUELS↗
DOE OSTI2026

Opportunities and challenges in thermochemical conversion of municipal solid waste: A comprehensive review

Recent advancements in thermochemical conversion processes have elucidated new pathways for converting municipal solid waste into valuable resources. This review explores the primary thermochemical conversion methods, including combustion, gasification, pyrolysis, torrefaction, hydrothermal carbonization, and hydrothermal liquefaction, emphasizing their potential roles in waste management and energy recovery. Key challenges including feedstock variability, ash behavior, and scale-up limitations are discussed alongside opportunities for hybrid systems and circular economy integration. A comparative analysis of research publications indicates a significant focus on thermochemical pathways within the broader context of municipal solid waste research, underscoring the growing interest in these technologies. Recent advancements in each thermochemical process, alongside their operational, technical, and economic challenges, are discussed. Comparative data reveal that torrefaction enhances the hydrophobicity and grindability of municipal solid waste components, though its energy densification benefits are more modest than those observed in biomass. Hydrothermal carbonization and liquefaction are highlighted for their ability to process high-moisture and heterogeneous waste streams. The review also synthesizes recent findings on reactor configurations, emissions control, and synergistic effects in co-processing municipal solid waste fractions. The findings underscore the importance of developing standardized protocols for municipal solid waste characterization and the need for innovative hybrid systems to improve efficiency.

99 - GENERAL AND MISCELLANEOUS↗
DOE OSTI2024

Porosity in Sr 1-x Ca x FeO 3-δ oxygen carriers: The role of surface area and pretreatment on storage activity

Perovskite oxides have generated interest as robust, low-temperature oxygen carrier materials for a variety of clean energy applications, including chemical looping gasification and air separations. Methods to improve O 2 desorption kinetics are vital to allow these carriers to compete economically with traditional metal oxide carriers or cryogenic separations. In this report we investigated the cumulative roles that surface area, pretreatment, and elemental composition have on the oxygen storage properties of a state-of-the-art carrier system, Sr 1-x Ca x FeO 3-δ (x = 0.20, 0.25, 0.30) synthesized using multiple methods. Porous materials synthesized by the Pechini, or citrate, method had their surface area controlled using the synthesis temperature. The high surface area of the Sr 0.7 Ca 0.3 FeO 3-δ materials is most beneficial at low operating temperatures, such as 350 and 400 °C, as their reduction rates are twice as fast as those obtained with their bulk counterparts. These effects are observed at higher operating temperatures and within a single composition, but temperature tunability using variable Ca 2+ substitution in the Sr 1-x Ca x FeO 3-δ overshadows the improvements gained from higher surface areas. Additionally, we establish that pretreatment in N2 at an elevated temperature is necessary to enhance kinetics further. For maximum efficiency, pretreatment at the synthesis temperature is suggested for the Pechini method-synthesized systems, whereas 800 °C is adequate for bulk materials.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Evaluating CO 2 mitigation strategies in SAF biorefineries: Techno-economic and life cycle analysis

The aviation sector requires scalable decarbonization strategies, and lignocellulosic sustainable aviation fuel (SAF) represents a promising pathway. This study comparatively evaluates the techno-economic analysis and life cycle assessment (LCA) of three CO 2 management strategies integrated within a U.S.-based gasification–Fischer–Tropsch SAF biorefinery: (i) catalytic hydrogenation of captured CO 2 to methanol, (ii) geological CO 2 sequestration, and (iii) mineralization to sodium bicarbonate (NaHCO 3 ). Techno-economic analysis indicates that methanol synthesis requires approximately 26% higher capital investment and 33% higher operating costs than mineralization. Although methanol co-production generates the highest gross revenue, NaHCO 3 production reduces the SAF minimum selling price by approximately 38% relative to both methanol synthesis and geological sequestration pathways, reflecting a more balanced cost allocation through mineral co-product valorization. Geological sequestration lowers operating costs by nearly 50% compared with methanol synthesis but remains highly dependent on carbon credit mechanisms. LCA reveals substantial divergence in climate performance. Relative to methanol synthesis, sequestration improves net greenhouse gas performance by approximately 163%, transitioning the system from net-positive to net-negative emissions. Mineralization further enhances carbon mitigation, achieving roughly 85% greater carbon reduction than sequestration and over sixfold improvement relative to methanol synthesis within the defined system boundary. Sensitivity analysis identified hydrogen price, co-product market value, and process emissions as dominant drivers. Under baseline assumptions, CO 2 mineralization is found to offer the most balanced pathway.

Carbon capture and storage↗
DOE OSTI2020

Life cycle greenhouse gas emissions of different CO 2 supply options for an algal biorefinery

This paper characterizes the greenhouse gas (GHG) emissions from the provision of CO 2 for twelve hours of the day from a range of sources operating on a twenty-four-hour basis. Twelve CO 2 supply cases spanning from fossil fuel power plant stack gases to direct air capture (DAC) systems are modeled. The results are compared in a life cycle assessment (LCA) framework. The CO 2 supply from the combustion or gasification of biomass has GHG emissions of –1.62 gCO 2 eq./g CO 2 delivered and is the case with the lowest carbon footprint for supplied CO2. The emissions for all the CO 2 supply cases were found to be negative, either because of capturing more CO 2 from the atmosphere than is released from the CO 2 production process, or because of production of excess electricity that is exported to the grid (replacing emissions from grid electricity). A purpose-built Natural Gas Combined Cycle (NGCC) power plant CO 2 source has the highest GHG emissions of -0.40 gCO 2 eq./gCO 2 delivered of the cases considered because of nighttime emissions and natural gas supply chain losses. The impact of a diurnal cycle can be mitigated by using capture and refrigeration systems as part of the CO 2 management system. The results are sensitive to the GHG emissions of the grid electricity, which is imported or exported in different cases. The results provide a benchmark for the comparison of different CO 2 supply options for the establishment of a sustainable algal biorefinery.

42 ENGINEERING↗
DOE OSTI2024

Pyrolysis of high-density polyethylene: Degradation behaviors, kinetics, and product characteristics

Pyrolysis is a promising technology for converting plastic waste into valuable raw materials while offering a potential solution to the global plastic pollution crisis. In this study, the thermal pyrolysis of high-density polyethylene (HDPE) is investigated in a drop tube reactor under nearly isothermal conditions. The impact of reaction temperature and gas/volatile residence time on carbon conversion and product distribution is examined across a range of 500–900°C and 3.6–32.2s, respectively. Non-condensable gas products detected by online mass spectrometry are H 2 , CH 4 , C 2 H 4 , C 2 H 6 , C 3 H 6 , and C 3 H 8 . At elevated temperatures and prolonged residence time, H 2 yield reaches as high as 8.6 wt% of the initial HDPE mass due to intensified cracking reactions of C 2 –C 3 hydrocarbons and long-chain aliphatic compounds. Consequently, pyrolysis tars consist mainly of polycyclic aromatic hydrocarbons (PAHs) with 5–7 rings, accompanied by visible coke deposition within the reactor. HDPE decomposition to volatiles is an endothermic process and it is complete at a temperature between 492°C and 525°C, depending on the heating rate employed, from non-isothermal thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) measurements. The thermal degradation of HDPE pellets follows the two-dimensional nucleation growth model for conversion levels up to 0.8 with an apparent activation energy of 259–270 kJ/mol and a pre-exponential factor of 4.83 × 10 17 –1.37 × 10 19 min -1 , determined from various isoconversional methods such as Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink, along with Criado's master plots. Further, these findings provide valuable insights into optimizing process parameters and refining reactor design for pyrolysis, which can be integrated with gasification and reforming processes to enhance hydrogen production on a larger scale.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Microwave-induced selective decomposition of cellulose: Computational and experimental mechanistic study

Understanding microwave-material interactions will help facilitate the utilization of microwave technology in gasification and renewable energy production. In this study, cellulose was used as a model compound to simulate the organic matter in biomass, and its catalytic decomposition under a microwave (MW) field was studied to identify structural changes from the reaction. The study was conducted using a MW source coupled to a fixed-bed gas-flow reactor, mass spectroscopic, and Fourier transform infrared spectroscopy post-reaction analysis. Zeolite 13X was chosen as a microwave absorber to study the catalytic enhancement of the decomposition of cellulose. Density functional theory (DFT) was used to gain insights into the molecular transformations occurring in the presence of a static electric field, which was used to simulate the electric field component of the microwave electromagnetic radiation. Theoretical calculations demonstrated that both the positive and negative portion of the electric field interact with the permanent dipoles of the cellulose effecting the decomposition through the glycosidic bond breaking mechanism. The theoretical result was verified using infrared spectroscopic analysis of the pure cellulose during microwave heating. The theoretical calculations suggest only the positive electric field component may be active for the cellulose decomposition in the presence of Zeolite 13X. Physically mixing Zeolite 13X with the cellulose led to a significant enhancement in the decomposition rate of the glycosidic bond. Zeolite 13X enhanced the glycosidic O-C decomposition at lower MW power (lower temperatures), whereas the O-H functional group required higher MW power (higher temperature) for its decomposition. The DFT study coupled with the reaction studies revealed that the electric field polarizability is dependent upon both the direction and the orientation of the cellulose. Gas products revealed that applying 250 W of MW power led to the production of CO, H 2 , along with some CO 2 , CH 4 , and benzene at 305 °C. Finally, reaction under 500, 750, and 1000 W of power at constant temperature (305 °C) revealed that higher power led to the complete decomposition of cellulose to mostly CO, H 2 , and CO 2 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Microporous pentiptycene-based polybenzimidazole membranes for high temperature H 2 /CO 2 separation

Separating H 2 from syngas at elevated temperatures (100–250 °C) have attracted significant attention in recent years as a means to reduce energy consumption and capital costs in precombustion carbon capture processes, such as those following steam reforming of natural gas or coal gasification. Polybenzimidazole (PBI), particularly m-PBI, has been reported as a leading membrane material for high-temperature H 2 /CO 2 separation. However, m-PBI exhibits extremely low H 2 permeability, even at high temperatures, which limits its productivity in H 2 /CO 2 separation applications. Here, to address this limitation, this work introduces a new pentiptycene-based polybenzimidazole (PPBI) featuring significantly enhanced H 2 permeability and attractive high-temperature H 2 /CO 2 separation performance, which stems from the unique configurational free volume elements introduced by pentiptycene moieties. Further tuning of the free volume architecture of PPBI films is achieved via acid doping with phosphoric acid (PA) or trans-aconitic acid (TaA), which introduces crosslinking among PPBI chains. Under mixed-gas environment (50/50 mol% H 2 /CO 2 ) at 180 °C, the acid-doped PPBI films exhibit a ∼230 % increase in H 2 /CO 2 selectivity compared to pristine PPBI film while maintaining high H 2 permeability that is nearly 500 % of m-PBI. These properties approach the predicted upper bound for membrane operating at 180 °C, highlighting its great potential for high-temperature H 2 /CO 2 separation.

Liu, Mengdi [University of Notre Dame, IN (United ↗
DOE OSTI2022

Scaling CFB risers: Maintaining microstructure dynamics

Over the years there have been numerous approaches to develop a scaleup methodology for circulating fluidized beds. Many of these past approaches have relied on macroscopic definitions of similitude to define dimensionless groups such as Reynolds number, Froude number, density ratios, and dimensional ratios involving different length scales. These approaches have demonstrated various levels of success, but often fail when used outside the bounds of experimental datasets. The issue with these methods is that they rely on macroscopic similitude with the hopes that those conditions would provide microscopic similitude as it does in single phase systems where the Buckingham Pi techniques have given reasonable success. Two of the main reasons for failure are 1) changing fluidization regimes and 2) changing material properties that result in the material falling into a different Geldart group. Both are certain to change the microstructure (local instantaneous volume solids fraction) and changes to the microstructure affect the interphase transport properties of the reactor system, namely the mass transfer and heat transfer. Here, this work presents a new approach towards scaling based upon maintaining similitude at the microscale. It reviews a novel dimensionless flow regime map developed from analysis of the deterministic chaos parameters and higher order moments to ensure microstructure similitude. The work then examines four cases from the literature to assess the scaling approach used: (1) same particle-different scale risers for Geldart Group B particles, (2) Glicksman scaling of atmospheric circulating fluidized bed combustor, (3) same particle-different scale risers for Geldart Group A particles and (4) Glicksman scaling for pressurized gasification. General findings are that none of the scaling approaches produced directly applicable microstructure similar behavior based upon the chaotic and higher moment analysis. The positive take away is that the approach can define scale conditions that will provide similar microstructure that can be us to predict transport behavior.

42 ENGINEERING↗
DOE OSTI2022

Detailed modeling of hydrogen release and particle shrinkage during pyrolysis of inhomogeneous wood

Hydrogen release during pyrolysis of woody biomass is studied considering anisotropicity and inhomogeneity of wood structure. A new anisotropic shrinkage model is proposed based on the decomposition of main wood constituents, i.e., cellulose, hemicellulose, and lignin. The new shrinkage model can predict the temporal evolution of the wood structure, and the differences between axial and radial shrinkage during pyrolysis. The model agrees very well with several experimental data from the literature. Based on particle temperature during conversion, the pyrolysis is partitioned into four stages, and the hydrogen release and H 2 formation from each stage are investigated. Stage (IV) of pyrolysis, from 1000 to 1273 K, is found to be efficient for H 2 production owing to the production of considerable mass of H with a minimal amount of tar species. Furthermore, the char quality is found to be different at the end of stages (II), (III), and (IV), where around 67.7, 80.5, and 93.4% wt. of solid residue is made of carbon, respectively. The model is also used to explain how the heating rate affects the temperature distribution inside the particle and how it shifts the peak of hydrogen release. Finally, the pyrolysis of two inhomogeneous wood samples — a beech twig with bark and a beech dowel with growth rings — are investigated. The bark can affect the pyrolysis rate, products, and flow pattern inside the particle. The growth rings do not have a considerable effect on the pyrolysis rate and products, but they have a significant impact on the flow pattern. This has an important implication for char conversion studies where the internal surface area and porosity field distribution have a significant effect on the gasification and oxidation rates.

09 BIOMASS FUELS↗
DOE OSTI2025

Process and environmental safety of thermochemical conversion of biomass

Biomass presents a promising opportunity for converting waste into valuable energy, fuels, and chemicals through various thermochemical processes, including hydrothermal carbonization, hydrothermal liquefaction, pyrolysis, gasification, and combustion. However, these processes operate under extreme conditions, introducing significant safety hazards that necessitate meticulous management to prevent accidents. This review discusses potential hazards, risk mitigation strategies, and safety management practices, emphasizing the importance of integrated safety measures into the design and operation of these processes. It also highlights the critical need for robust safety engineering and environmental management strategies tailored to each thermo-chemical process. As these processes transition from laboratory to industrial scale, there is an imperative to develop a clear and concise pathway for emerging industries to achieve regulatory compliance, achieve safety certification, and enable effective stewardship of potential fugitive emissions. By addressing safety and environmental concerns, stakeholders can optimize economic benefits, rural development, and achieve sustained domestic energy generation benefits offered by biomass conversion technologies. Further research on plant design optimization, operational safety, environmental evaluation standardization, and innovative waste management solutions will support the safe and effective scaling of these technologies, ultimately contributing to sustainable management and resource recovery.

09 - BIOMASS FUELS↗
DOE OSTI2021

Effect of Biochar and Biochar Particle Size on Plant-Available Water of Sand, Silt Loam, and Clay Soil

Biochar is being used as a soil amendment to improve soil hydraulic properties. It has been reported that biochar increases plant-available water, particularly in coarse-textured soils; however, effects on fine-textured soils are less pronounced. Here, we quantified the effects of biochar particle size on plant-available water in sand, silt loam, and clay soils. We amended these soils with a hydrophilic biochar, and packed soil-biochar mixtures into columns of 5.35-cm diameter and 3.0-cm height. Biochar was produced by gasification of woody forest residues. We applied the biochar at two different rates (0.5\% and 2\% by weight of C) and with four different biochar particle-size fractions ($<$4.75, $<$2.0, $<$1.0 and $<$0.5 mm). Our results show that biochar amendments increased the plant-available water (when expressed gravimetrically) of all three soils, particularly at the highest biochar application rate. Although the absolute increase in plant-available water was largest for the silt loam soil, the relative increase of plant-available water was greater for the sand than for the silt loam and clay. When expressed in volumetric terms, however, the effects on water retention were less pronounced: the sand showed a small increase in plant-available water with biochar amendment, and no change was observed with the silt loam and clay. Particle size of biochar had little effect on plant-available water (when expressed in gravimetric terms) in the three soils, but silt loam and clay showed increased plant-available water (when expressed in volumetric terms) with decreasing biochar particle size, while no effect was observed for the sand. While our findings corroborate many of the previously reported effects of biochar on soil-water retention, we show that the effects and their magnitude depend on whether the results are reported in terms of gravimetric or volumetric water contents. Because bulk density tends to decrease with increasing biochar application, so will the volumetric water content, and thus the magnitude of the effect on plant-available water will be smaller when expressed in volumetric water content.

hydraulic properties, water holding capacity, soil↗
DOE OSTI2026

Biomass Demineralization: A Critical Need for Future Biorefineries

Biomass contains up to 14 essential elements that serve as nutrients for plant growth and development, including photosynthesis and enzyme functionalities. These elements in different chemical forms (e.g., minerals) constitute the inorganic fraction of biomass and can cause operational issues in thermal and biochemical biomass conversion technologies. In biomass gasification and pyrolysis processes, for instance, inorganics can cause fouling, tar formation, and corrosion. In catalytic and biochemical processes, inorganics can poison catalysts, alter biochemical pathways, and modify product yields and selectivity. This review provides an overview of the inorganic content in biomass feedstocks, the critical role inorganics play in plant biochemistry, the effect that inorganics have in various thermochemical and biochemical biomass conversion technologies, and different approaches to remove them from biomass. We provide recommendations for future research, focusing on developing technologies to effectively remove inorganics from biomass, using the inorganics to improve soil quality and for alternative applications, and designing biorefineries to convert demineralized biomass obtained from diverse sources.

09 - BIOMASS FUELS↗