Results for “hydrothermal” — Page 12

DOE OSTI2023

Microalgae Hydrothermal Liquefaction and Biocrude Upgrading: 2022 State of Technology

A preliminary techno-economic analysis (TEA) was developed for the fiscal year (FY) 2022 state of technology (SOT) assessment to evaluate the benefits and risks of using demonstrated, high-productivity algae strains for fuels generation, including sustainable aviation fuel (SAF). In 2022, the marine algal strain, Picochlorum celeri, which demonstrated the highest outdoor biomass productivities reported to date in the DOE-funded open-pond raceway testbed at the Arizona Center for Algae Technology and Innovation (AzCATI), was tested for continuous hydrothermal liquefaction (HTL) processing at PNNL. HTL testing results demonstrated a biocrude yield of 0.33 g/g algae on an ash-free dry weight (AFDW) basis from P. celeri. The hydrotreatment testing of the HTL biocrude from P. celeri was also conducted to investigate the production of jet fuel from marine algal biomass. To the best of our knowledge, this is the first report of jet fuel production from autotrophically grown marine algal biomass. The current hydrotreating testing demonstrated approximately 22.7 wt% of the hydrotreated oil within the typical boiling-point range of jet fuel (150–250 °C). Initial testing of the jet fuel cut (JFC) showed that the physical properties under investigation were within typical ranges for petroleum-based jet fuels. The experimental work of this study closes the gap between outdoor algae cultivation and algae conversion to critical transportation fuels using the same algae strain for both cultivation and conversion testing. The continuous HTL and the upgrading testing described herein demonstrate the potential of producing sustainable aviation fuel (SAF) from algae cultivated in open-pond systems using the primary inputs of sunlight and carbon dioxide.

09 BIOMASS FUELS↗

DOE OSTI2021

Hydrothermal Liquid Recovery of Rare Earth Elements and Critical Materials

This project demonstrated the technical viability of using tunable hydrothermal liquid (HTL) solutions to recover valuable minerals from a range of source materials. The effort focused upon rare earth elements (REE) and other minerals critical to the industrial security of the United States. This effort demonstrated, for the first time, that s, supercritical water (SCW) in particular, can: Extract critical and valuable minerals from a range of matrices ranging from rock ore to biomass; The process can be used to recover a wide range of minerals; This novel extraction chemistry can be cheap, simple, and nontoxic/”green”: The chemical extraction uses water, the cheapest industrial acid (sulfuric), and simple salts (i.e. sodium sulfate). However, other acids, salts, and additives could be used as appropriate. This Laboratory Directed Research and Development (LDRD) project identified that the process is complex with many interacting factors, but the benefits are significant if the complexities can be resolved. Challenges remain in the development of this technology and are described in this report. However, the results are positive, and commercial partners have already expressed interest. In summary, a novel, green, inexpensive mineral extraction process has been developed and demonstrated in a small batch reactor system. The effort provided information for an invention disclosure, proposal to DOE, and will support future business development efforts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

Laser Driven Hydrothermal Processing (LDHP) for Rapid Dissolution of Glassy Nuclear Debris

Discovered in 2009 on the SLAB laser system at LLNL, Laser-Driven Hydrothermal Processing (LDHP) both spalls and transiently dissolves a wetted surface (e.g., rock, concrete, paint) when that surface is struck by a laser beam pulse under specific conditions. Previous projects have explored the application of LDHP to expediting sample dissolution for post-detonation nuclear forensics. Early results were very promising, indicating that this method could decrease material dissolution time by a factor of 10 or more. However, the large and complicated lasers previously used are impractical for this application. Under the R^3 venture we aimed to benchmark the LDHP capabilities of turn-key commercial off-the-shelf (COTS) lasers, and to establish how this process could be integrated into an analytical workflow for nuclear forensic analysis. We demonstrated that geological rock standards could be quickly processed into fine powder by LDHP followed by complete acid digestion in 15 minutes, without elemental fractionation that would skew analytical results. We determined that the COTS laser can be used for LDHP that could potentially reduce dissolution time for solid nuclear debris samples in post detonation nuclear forensics. One downside to this approach, however, is that the laser interactions are different with every material, so extensive method validation would be required for all likely material compositions. The LDHP processing rates of several materials were tested and determined to be favorable in the beginning with significant slowdown due to particulate scattering. This could be mitigated either by stopping and centrifuging the sample at specific intervals, or through design of a continuous solvent flow through mechanism.

36 MATERIALS SCIENCE↗

DOE OSTI2024

Site-specific Design Case Study for Wet Waste Hydrothermal Liquefaction and Biocrude Upgrading to Hydrocarbon Fuels

Hydrothermal liquefaction (HTL) is a thermal process that converts wet biomass to renewable hydrocarbon fuel blendstocks (i.e., renewable naphtha, renewable diesel, and sustainable aviation fuel (SAF)). It can utilize a wide range of pure and blended wet feedstocks, including sewage sludge from water resource recovery facilities (WRRF), food and agriculture wastes, algae, fats, oils and greases (FOG) and blends of dry and wet wastes/feedstocks. Historically, techno-economic analysis (TEA) and annual state of technology (SOT) assessments with standard economic assumptions used by the Bioenergy Technologies Office (BETO) were conducted for the wet waste HTL pathway leveraging experimental data collected from Pacific Northwest National Laboratory’s (PNNL) continuous flow reactor systems. The objective of the SOT assessment has been to guide and track progress of BETO’s HTL research and development (R&D) toward reduced cost and greenhouse gas (GHG) emissions for the pathway. However, gaps exist between BETO’s traditional SOT updates and the needs of key external stakeholders that – if addressed – will accelerate technology adoption. This Business Case Study aims to bridge this gap by providing an updated design, TEA, and LCA based on PNNL’s FY23 R&D with added analyses and information that provide enhanced relevance for stakeholders of the HTL technology. This includes specific siting, regional wet waste resource inventory and transportation cost analyses, fuel market information, sustainable fuel policy impacts, economic metrics of net present value (NPV) and internal rate of return (IRR), greenhouse gas (GHG) emissions analysis, and statistical analysis of cost and technical uncertainties of the HTL plant design. The study focuses on the “Detroit combined statistical area (CSA)” region for siting of a wet waste HTL plant adjacent to the Great Lakes Water Authority (GLWA) facility with guidance from industry participants. Regional resource and siting analyses were conducted to identify feedstock availability, scale, and cost, as well as a beneficial site location. TEA with detailed rigorous capital cost estimation for the specific site application was conducted to evaluate the key economic metrics of most value to industrial partners. These include total capital investment, operating costs, minimum fuel selling price (MFSP) of the biocrude and fuel blendstock, and NPV and internal rate of return IRR with sustainable fuel credits. Life cycle analysis was conducted to evaluate the supply chain greenhouse gas (GHG) emissions for the wet waste HTL process as compared with petroleum derived diesel. This study is also informed by years of R&D and process de-risking learnings and was conducted with a basic engineering HTL plant design and costing that akin to a “first-of-a-kind” plant economics. This differs from our conventional “nth plant ” SOT assessments. Specifically, the HTL process model has been updated with more operationally reliable methods for feed heating and phase separations. Further, we have implemented additional spare equipment for redundancy, a more rigorous installed equipment cost estimation approach, and additional costs associated with feed formatting and delivery, building, piping and site development. An Excel-based cost sheet based on the basic engineering design is also released alongside the report that allows users to conduct customized TEA with their own feed composition and financial assumptions.

09 BIOMASS FUELS↗

DOE OSTI2024

2023 Business Case Study: Hydrothermal Liquefaction of Algal Bloom Biomass

A business case study was developed for the fiscal year (FY) 2023 to explore the technical and economic feasibility of converting lake-harvested algal bloom biomass (ABB) into biofuel via hydrothermal liquefaction (HTL). The case study includes reporting on the experimental demonstration of converting the algal feedstock to HTL biocrude. Using the experimental data, a preliminary techno-economic assessment (TEA) of a commercial-scale facility was completed to determine the economic feasibility of the process.

09 BIOMASS FUELS↗

DOE OSTI2025

2024 Case Study: Hydrothermal Liquefaction of Biomass Sources at a Wastewater Treatment Facility

A case study was developed for the fiscal year 2024 to examine the potential of wastewater-grown microalgae as a feedstock for hydrothermal liquefaction (HTL) to produce fuels and other products. In this year’s case study, scenarios are investigated in which the algae cultivation process is placed at different points within the water resource recovery facility (WRRF). Additionally, the supply of biomass for HTL is boosted by blending with wastewater solids collected at different locations within the WRRF.

09 BIOMASS FUELS↗

DOE OSTI2025

Whole Algae Hydrothermal Liquefaction and Upgrading: A review of progress and challenges and insight into the future

This report summarizes the research at Pacific Northwest National Laboratory (PNNL) to evaluate the economic viability and environmental impact of using microalgae to produce fuels and other products via hydrothermal liquefaction (HTL). Over the past several years, PNNL has examined key aspects of feedstock cost and availability, formatting and conversion techniques, and the utilization of all HTL products. Investigations of feedstock cost led to opportunities to work with cost-advantaged algal feedstocks that can be provided at minimal cost for HTL processing. Cost-advantaged algae include wastewater-grown algae and harvested algal blooms. Although farm-cultivated algae offer the best possible biomass composition and scalability for HTL processing, the cost of the feedstock is too high to yield an economically competitive biofuel. Processing cost-advantaged feedstocks creates other unique challenges in adapting HTL to upgrade biomass with higher than typical ash content and less preferred composition (low lipid). Despite the challenges, HTL of cost-advantaged algae results in economically competitive pricing scenarios and significant advantages in reducing net emissions below 70% of the petroleum baseline. The utilization of a variety of potential non-fuel products from algal HTL, such as the use of HTL solids as a cement additive, provides a significant reduction in net emissions by offsetting emissions from other carbon-intense products. This report presents an analysis of the research conducted at PNNL to develop an economically and environmentally beneficial process for algae HTL.

09 BIOMASS FUELS↗

DOE OSTI2026

Algae Hydrothermal Liquefaction: End-of-Project Report

This document is a close-out report for two Pacific Northwest National Laboratory (PNNL) projects funded by the Alternative Fuels and Feedstocks Office (formerly the Bioenergy Technologies Office) of the Department of Energy (DOE). The two projects are: • Thermochemical Interface (DOE ref. no. 1.3.4.101, PNNL ref. no. 64490) • HTL Model Development (DOE ref. no. 1.3.5.202, PNNL ref. no. 71612) At the end of fiscal year 2025, both projects ended. Additional activities related to the topics of algae, hydrothermal liquefaction (HTL), and the techno-economic assessment of HTL of algal feedstocks will be studied in other projects. Key technical findings of the projects were published in early 2025 and highlights will be summarized in this document. A summary of recent technical findings from 2025 are also included herein. This close-out report summarizes key outcomes from both projects highlighting the value and technical impact achieved.

09 BIOMASS FUELS↗

DOE OSTI2024

Supporting data for Site-specific Design Case Study for Wet Waste Hydrothermal Liquefaction and Biocrude Upgrading to Hydrocarbon Fuels

Hydrothermal liquefaction (HTL) is a thermal process that converts wet biomass to renewable hydrocarbon fuel blendstocks (i.e., renewable naphtha, renewable diesel, and sustainable aviation fuel (SAF)). It can utilize a wide range of pure and blended wet feedstocks, including sewage sludge from water resource recovery facilities (WRRF), food and agriculture wastes, algae, fats, oils and greases (FOG) and blends of dry and wet wastes/feedstocks. Historically, techno-economic analysis (TEA) and annual state of technology (SOT) assessments with standard economic assumptions used by the Bioenergy Technologies Office (BETO) were conducted for the wet waste HTL pathway leveraging experimental data collected from Pacific Northwest National Laboratory’s (PNNL) continuous flow reactor systems. The objective of the SOT assessment has been to guide and track progress of BETO’s HTL research and development (R&D) toward reduced cost and greenhouse gas (GHG) emissions for the pathway. However, gaps exist between BETO’s traditional SOT updates and the needs of key external stakeholders that – if addressed – will accelerate technology adoption. This Business Case Study aims to bridge this gap by providing an updated design, TEA, and LCA based on PNNL’s FY23 R&D with added analyses and information that provide enhanced relevance for stakeholders of the HTL technology. This includes specific siting, regional wet waste resource inventory and transportation cost analyses, fuel market information, sustainable fuel policy impacts, economic metrics of net present value (NPV) and internal rate of return (IRR), greenhouse gas (GHG) emissions analysis, and statistical analysis of cost and technical uncertainties of the HTL plant design. The study focuses on the “Detroit combined statistical area (CSA)” region for siting of a wet waste HTL plant adjacent to the Great Lakes Water Authority (GLWA) facility with guidance from industry participants. Regional resource and siting analyses were conducted to identify feedstock availability, scale, and cost, as well as a beneficial site location. TEA with detailed rigorous capital cost estimation for the specific site application was conducted to evaluate the key economic metrics of most value to industrial partners. These include total capital investment, operating costs, minimum fuel selling price (MFSP) of the biocrude and fuel blendstock, and NPV and internal rate of return IRR with sustainable fuel credits. Life cycle analysis was conducted to evaluate the supply chain greenhouse gas (GHG) emissions for the wet waste HTL process as compared with petroleum derived diesel. This study is also informed by years of R&D and process de-risking learnings and was conducted with a basic engineering HTL plant design and costing that akin to a “first-of-a-kind” plant economics. This differs from our conventional “nth plant ” SOT assessments. Specifically, the HTL process model has been updated with more operationally reliable methods for feed heating and phase separations. Further, we have implemented additional spare equipment for redundancy, a more rigorous installed equipment cost estimation approach, and additional costs associated with feed formatting and delivery, building, piping and site development. An Excel-based cost sheet based on the basic engineering design is also released alongside the report that allows users to conduct customized TEA with their own feed composition and financial assumptions.

Li, Shuyun↗

DOE OSTI2020

Chemical Free Two-Step Hydrothermal Pretreatment to Improve Sugar Yields from Energy Cane

Energy cane is an attractive lignocellulosic feedstock for processing into biofuels and bioproducts. A low-severity two-step hydrothermal pretreatment was investigated on energy cane for the production of monomeric sugar. Pretreatment temperature and time, in addition to the effect of disk milling, were observed for the glucose and xylose yields during hydrolysis. At residence times above 5 min in case of pretreatment at 200 °C, all of the hemicellulose was observed to be solubilized. The pretreatment condition of 200 °C for 10 min with disk milling was observed to provide the highest glucose concentration of 5.4%, and 200 °C for 5 min with disk milling provided the highest xylose concentration of 2.15%. The effect of disk milling in improving the sugar concentrations during hydrolysis was significant, especially at lower pretreatment temperatures and times. Low xylose yields at higher temperatures were attributed to the formation of degradation products at increased severity.

09 BIOMASS FUELS↗

DOE OSTI2021

Hydrothermal Synthesis and Structural Investigation of a Crystalline Uranyl Borosilicate

The relevance of multidimensional and porous crystalline materials to nuclear waste remediation and storage applications has motivated exploratory research focused on materials discovery of compounds, such as actinide mixed-oxoanion phases, which exhibit rich structural chemistry. The novel phase K1.8Na1.2[(UO2)BSi4O12] has been synthesized using hydrothermal methods, representing the first example of a uranyl borosilicate. The three-dimensional structure crystallizes in the orthorhombic space group Cmce with lattice parameters a = 15.5471(19) Å, b = 14.3403(17) Å, c = 11.7315(15) Å, and V = 2615.5(6) Å3, and is composed of UO6 octahedra linked by [BSi4O12]5− chains to form a [(UO2)BSi4O12]3− framework. The synthesis method, structure, results of Raman, IR, and X-ray absorption spectroscopy, and thermal stability are discussed.

Pace, Kristen A. (ORCID:0000000185748939)↗

DOE OSTI2021

Simultaneous Electrospinning and Electrospraying for the Preparation of a Precursor Membrane Containing Hydrothermally Generated Biochar Particles to Produce the Value-Added Product of Carbon Nanofibrous Felt

Biochar is a byproduct generated from the hydrothermal liquefaction of biomass, such as corn stover, in an anaerobic environment. This work aims to convert biochar into a value-added product of carbon nanofibrous felt. First, the biochar-containing precursor membrane was prepared from simultaneous electrospinning and electrospraying. After thermal stabilization in air and carbonization in argon, the obtained precursor membrane was converted into a mechanically flexible and robust carbon nanofibrous felt. Electrochemical results revealed that the biochar-derived carbon nanofibrous felt might be a good candidate as a supercapacitor electrode with a good rate capability and high kinetic performance.

25 ENERGY STORAGE↗

DOE OSTI2020

Hydrothermal aging-resistant plastic scintillator formulations

A plastic scintillator includes an anti-fog additive or comonomer. The plastic scintillator is formulated to resist the development of hydrothermally-induced aging defects (e.g. discoloration and “fogging”) while maintaining scintillation light output and other desirable physical properties.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Geology and Hydrothermal Alteration of the Raft River Geothermal System, Idaho

The Raft River geothermal system is located in southern Idaho, near the Utah-Idaho state boarder in the Raft River Valley. The field, which is owned and operated by U.S. Geothermal, has been selected as an EGS demonstration site by the U. S. Department of Energy. This paper summarizes ongoing geologic and petrologic investigations being conducted in support of this project. The reservoir is developed in fractured Proterozoic schist and quartzite, and Archean quartz monzonite cut by younger diabase intrusions. The basement complex was deformed during the mid Tertiary and covered by approximately 5000 ft of late Tertiary sedimentary and volcanic deposits. Listric normal faults of Cenozoic age disrupt the Tertiary deposits but do not offset the basement rocks. RRG-9, the target well, was drilled southwest of the main well field to a measured depth (MD) of 6089 ft. The well is deviated to the west and cased to a depth of 2316 ft MD. It penetrated the Proterozoic reservoir rocks at a depth of 5286 ft MD and encountered a maximum temperature of 139 degrees C. Bottomhole temperatures in other deep wells range from 133 to 149 degrees C. X-ray diffraction and thin section analyses are being conducted on samples from 5 deep wells, RRG- 1, 2, 3, 7 and 9, to determine the characteristics of the rock types and hydrothermal alteration within the geothermal system. Thin section analyses of samples from RRG-9 document the presence of strong alteration and brecciation at the contact between the Tertiary and basement complex. The Tertiary rocks consist of ash-flow tuffs, lava flows, tuffaceous siltstone, greywacke, and sandstone. No core is available from RRG-9 but core was obtained from RRG-3C. The sample is a brecciated and altered siltstone from the base of the Tertiary sequence and is similar to rocks at the base of the Tertiary deposits in RRG-9. Here, the results of thermal and quasi-static mechanical property measurements that were conducted on the core sample are presented.

Jones, Clay↗

DOE OSTI2021

Swell Behavior of Elastomers with a Hydrothermal Liquefaction Bio-Crude and a Fast Pyrolysis Bio-Oil

The compatibility of seventeen elastomer materials with two heavy biofuels (fast pyrolysis bio-oil and hydrothermal liquefaction (HTL) bio-crude) and diesel was assessed through volume change measurements. The elastomers included two fluorocarbons, six acrylonitrile rubbers (NBRs), and one each of fluorosilicone, neoprene, polyurethane, silicone, epichlorohydrin rubber (ECO), a blend of polyvinyl chloride and NBR (OZO), styrene butadiene rubber (SBR), hydrogenated NBR (HNBR) and ethylene propylene diene monomer (EPDM). The specimens were immersed in each test fuel for four weeks at 50°C and then measured for volume change. Afterwards, the specimens were dried, and the volume was remeasured. Ingeneral, the bio-oil produced unacceptable swelling in the fluoroelastomers, ECO, OZO, neoprene, polyurethane, SBR, HNBR, EPDM, silicone and five of the NBRs. In most cases, the HTL bio-crude produced lower (though still unacceptable) swelling than the bio-oil. Materials that showed good compatibility with the HTL biocrude were the fluoroelastomers, OZO, and silicone.

Kass, Michael↗

DOE OSTI2022

Hydrothermal liquefaction system

A hydrothermal liquefaction (HTL) system can comprise a biomass slurry source, a first pump in fluid communication with the slurry source and configured to pressurize a biomass slurry stream from the slurry source to a first pressure, a first heat exchanger in fluid communication with the first pump and configured to heat a slurry stream received from the first pump to a first temperature, a second pump in fluid communication with the first heat exchanger and configured to pressurize a slurry stream received from the first heat exchanger to a second pressure higher than the first pressure, a second heat exchanger in fluid communication with the second pump and configured to heat a slurry stream received from the second pump to a second temperature higher than the first temperature, and a HTL reactor configured to produce biocrude from a slurry stream received from the second heat exchanger.

Thorson, Michael R.↗

DOE OSTI2023

Hydrothermal liquefaction system

A hydrothermal liquefaction (HTL) system can comprise a biomass slurry source, a first pump in fluid communication with the slurry source and configured to pressurize a biomass slurry stream from the slurry source to a first pressure, a first heat exchanger in fluid communication with the first pump and configured to heat a slurry stream received from the first pump to a first temperature, a second pump in fluid communication with the first heat exchanger and configured to pressurize a slurry stream received from the first heat exchanger to a second pressure higher than the first pressure, a second heat exchanger in fluid communication with the second pump and configured to heat a slurry stream received from the second pump to a second temperature higher than the first temperature, and a HTL reactor configured to produce biocrude from a slurry stream received from the second heat exchanger.

Thorson, Michael R.↗

DOE OSTI2024

Hydrothermally stable methane oxidation catalyst

A method of manufacturing a methane oxidation catalyst and methane oxidation catalysts formed by the method are provided. The method includes providing a palladium (Pd)-based catalyst including Pd dispersed onto a support. A magnesium (Mg) precursor is introduced to the Pd-based catalyst by one of ion exchange or incipient wetness impregnation. After introducing the magnesium precursor to the Pd-based catalyst, the catalyst is dried and subjected to a final heat treatment that includes hydrothermal calcination. A method of methane oxidation in a lean exhaust environment via the methane oxidation catalyst is also provided.

DeBusk, Melanie M.↗