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At least 145 records · Page 8

Thiol-promoted catalytic synthesis of high-performance furan-containing lubricant base oils from biomass derived 2-alkylfurans and ketones

About 97% of lubricant base oils are currently sourced from petroleum and the majority of the rest is produced from vegetable oils. We demonstrate a promising catalytic route to produce base oils from lignocellulosic biomass-derived 2-alkylfurans and ketones via carbon–carbon coupling in neat conditions. Among several homogeneous and heterogeneous acid catalysts tested, a perfluorinated sulfonic acid (Aquivion PW79S) exhibits the best catalytic performance and yields up to 90% renewable furan-containing base oils with the use of a thiol promotor. The effects of the acid strength of the catalysts, molecular size and structure of thiols and ketones, and fraction of thiols are studied. Electronic structure calculations elucidate the reaction pathway and indicate that the thiol reduces the barrier of the rate-determining dehydration step. The structure and properties of base oils can be tuned by using different synthons. Here, these base oils have excellent properties and can be competitive with or surpass the commercial synthetic alkylnaphthalene and furan-containing bio-ester base oils.

09 BIOMASS FUELS↗

Metabolic and transcriptomic study of pennycress natural variation identifies targets for oil improvement

Pennycress (Thlaspi arvense L.), a member of the Brassicaceae family, produces seed oil high in erucic acid, suitable for biodiesel and aviation fuel. Although pennycress, a winter annual, could be grown as a dedicated bioenergy crop, an increase in its seed oil content is required to improve its economic competitiveness. The success of crop improvement relies upon finding the right combination of biomarkers and targets, and the best genetic engineering and/or breeding strategies. In this work, we combined biomass composition with metabolomic and transcriptomic studies of developing embryos from 22 pennycress natural variants to identify targets for oil improvement. The selected accession collection presented diverse levels of fatty acids at maturity ranging from 29% to 41%. Pearson correlation analyses, weighted gene co‐expression network analysis and biomarker identifications were used as complementary approaches to detect associations between metabolite level or gene expression and oil content at maturity. The results indicated that improving seed oil content can lead to a concomitant increase in the proportion of erucic acid without affecting the weight of embryos. Processes, such as carbon partitioning towards the chloroplast, lipid metabolism, photosynthesis, and a tight control of nitrogen availability, were found to be key for oil improvement in pennycress. Besides identifying specific targets, our results also provide guidance regarding the best timing for their modification, early or middle maturation. Thus, this work lays out promising strategies, specific for pennycress, to accelerate the successful development of lines with increased seed oil content for biofuel applications.

59 BASIC BIOLOGICAL SCIENCES↗

Performance of Low Salinity Polymer Flood in Enhancing Heavy Oil Recovery on the Alaska North Slope

Combining low-salinity water (LSW) and polymer flooding was proposed to unlock the tremendous heavy oil resources (20–25 billion barrels) on the Alaska North Slope (ANS). The synergy effect of LSW and polymer flooding was demonstrated through coreflooding experiments carried out on representative rock and fluid systems. The results indicate that the high-salinity polymer solution (HSP, 2,300 ppm, salinity=27,500 ppm) requires nearly two thirds more polymer than the low-salinity polymer (LSP, 1,400 ppm, salinity=2,500 ppm) to achieve the same target viscosity of 45 cp measured from viscometer. Additional oil (5–9%) can be recovered from LSW flooding after extensive high-salinity water (HSW) flooding. LSW flooding performed in secondary mode can achieve higher recovery than in tertiary mode. Strikingly, LSP flooding can further improve the oil recovery by ~8% even after extensive HSP flooding with the same viscosity. LSP flooding performed directly after waterflooding can achieve ~10% more incremental oil recovery. The pH increase of the effluent during LSW/LSP flooding was significantly greater than that during HSW/HSP flooding, indicating the occurrence of ion exchange which might contribute to the improved oil recovery. Also, the water breakthrough was delayed in a low-salinity flood compared with a high-salinity flood. The idea of combining LSW and polymer flooding has been put into practice on a pattern-scale field pilot test in the target Milne Point field. Nearly two-year observation has shown impressive success: water cut reduction (70% to below 15%), increasing oil rate, and no polymer breakthrough so far. This work has demonstrated remarkable economical and technical benefits of combination of LSW and polymer flooding in enhancing heavy oil recovery.

Zhao, Yang↗

First Ever Polymer Flood Field Pilot to Enhance the Recovery of Heavy Oils on Alaska North Slope – Producer Responses and Operational Lessons Learned

The US Department of Energy and Hilcorp Alaska, LLC are jointly cosponsoring a field pilot project entitled “First Ever Field Pilot on Alaska’s North Slope to Validate the Use of Polymer Floods for Heavy Oil Enhanced Oil Recovery (EOR).” The objective of this pilot is to perform a field experiment to validate the use of an advanced polymer flooding technology to unlock the vast heavy oil resources on Alaska North Slope (ANS). Two pairs of horizontal injection and production wells have been deployed in an isolated fault block of the Schrader Bluff heavy oil reservoir at the Milne Point Field to conduct a polymer flood pilot which was designed to acquire field performance data to optimize polymer flood design in the Schrader Bluff heavy oil reservoirs on ANS. Hydrolyzed polyacrylamide (HPAM) polymer injection started on August 28, 2018 using a custom made polymer mixing and pumping unit. Polymer solution properties such as concentration, viscosity, and filter ratio, have been closely monitored and adjusted as necessary. Operational procedures have been improved to ensure adequate injectivity and polymer propagation through the formation. Oil and water production is tested frequently to monitor water cut performance, and produced water is sampled and analyzed for polymer content. Tracers were pumped pre and post polymer injection startup to compare polymer flood breakthrough timing and sweep efficiency. Polymer injectivity of the horizontal wells drilled in the Schrader Bluff NB sand is found to be sufficient to replace the reservoir production voidage although there were some declines as high viscosity polymer swept the near wellbore region. Production data show significant reduction in water cut and the oil production rate has stabilized. No polymer production has been confirmed from the two horizontal producers after 22 months of polymer injection into the two supporting horizontal injectors. Tracer data show very low sweep efficiencies with waterflood alone, whereas significant improvement has been achieved with polymer flood. Many operational lessons have been learned and improvements have been made regarding polymer mixing, pumping, and onsite quality control, particularly in a challenging Arctic environment. Adequate polymer injection rate can be achieved with diligent monitoring and quality assurance of the properties of the injected polymer solution.

Ning, Samson↗

An Eight-County Appraisal of the San Andres Residual Oil Zone (ROZ) 'Fairway' of the Permian Basin

This document assesses the size and distribution of the oil resource in an eight-county portion of the San Andres residual oil zone (ROZ) fairway in the Permian Basin. Using well log analysis, the study divided the ROZ into partitions, developed a database of geologic properties for each partition and estimated the oil in place in each partition. The study then used the FE/NETL CO 2 Prophet Model to estimate the oil that could be produced and CO 2 stored from applying CO 2 EOR to each partition. With the FE/NETL Onshore CO 2 EOR Cost Model, the commercially viable partitions were identified as those that could produce oil and store CO 2 economically at an oil price of $75/STB. The remaining geologically viable partitions could use CO 2 EOR to store CO 2 with production of oil to offset some of the costs. The database used for this study, and a report describing the database is available on NETL's website under the Collection Name Eight-County San Andres ROZ Appraisal.

02 PETROLEUM↗

A Four-County Appraisal of the San Andres Residual Oil Zone (ROZ) 'Fairway' of the Permian Basin

This document assesses the size and distribution of the oil resource in a four-county portion of the San Andres residual oil zone (ROZ) fairway in the Permian Basin. Using well log analysis, the study divided the ROZ into partitions, developed a database of geologic properties for each partition and estimated the oil in place in each partition. The study then used the FE/NETL CO 2 Prophet Model to estimate the oil that could be produced and CO 2 stored from applying CO 2 EOR to each partition. With the FE/NETL Onshore CO 2 EOR Cost Model, the commercially viable partitions were identified as those that could produce oil and store CO 2 economically at an oil price of $75/STB. The remaining geologically viable partitions could use CO 2 EOR to store CO 2 with production of oil to offset some of the costs. The database used for this study, and a report describing the database is available on NETL's website under the Collection Name: Four-County San Andres ROZ Appraisal.

02 PETROLEUM↗

2023 Annual Report of Available Drawdowns for Each Oil Storage Cavern in the Strategic Petroleum Reserve

DOE maintains an up-to-date documentation of the number of available full drawdowns of each of the caverns at the U.S. Strategic Petroleum Reserve (SPR). This information is important for assessing the SPR’s ability to deliver oil to domestic oil companies expeditiously if national or world events dictate a rapid sale and deployment of the oil reserves. Sandia was directed to develop and implement a process to continuously assess and report the evolution of drawdown capacity, the subject of this report. This report covers impacts on drawdown availability due to SPR operations during Calendar Year 2022. A cavern has an available drawdown if, after that drawdown, the long-term stability of the cavern, the cavern field, or the oil quality are not compromised. Thus, determining the number of available drawdowns requires the consideration of several factors regarding cavern and wellbore integrity and stability, including stress states caused by cavern geometry and operations, salt damage caused by dilatant and tensile stresses, the effect of enhanced creep on wellbore integrity, and the sympathetic stress effect of operations on neighboring caverns. Finite-element geomechanical models have been used to determine the stress states in the pillars following successive drawdowns. By computing the tensile and dilatant stresses in the salt, areas of potential structural instability can be identified that may represent red flags for additional drawdowns. These analyses have found that many caverns will maintain structural integrity even when grown via drawdowns to dimensions resulting in a pillar-to-diameter ratio of less than 1.0. The analyses have also confirmed that certain caverns should only be completely drawn down one time. As the SPR caverns are utilized and partial drawdowns are performed to remove oil from the caverns (e.g., for oil sales, purchases, or exchanges authorized by the Congress or the President), the changes to the cavern caused by these procedures must be tracked and accounted for so that an ongoing assessment of the cavern’s drawdown capacity may be continued. A methodology for assessing and tracking the available drawdowns for each cavern is reiterated. This report is the latest in a series of annual reports, and it includes the baseline available drawdowns for each cavern, and the most recent assessment of the evolution of drawdown expenditures. A total of 222 million barrels of oil were released in calendar-year 2022. A nearly-equal amount of raw water was injected, resulting in an estimated 34 million barrels of cavern leaching. Twenty caverns have now expended a full drawdown. Cavern BC 18 has expended all its baseline available drawdowns, and has no drawdowns remaining. Cavern BM 103 has expended one of its two baseline drawdowns, and is now a single-drawdown cavern. All other caverns with an expenditure went from at-least-5 to at-least-4 remaining drawdowns.

02 PETROLEUM↗

Technical and Economic Assessment and Gap Analysis of Advanced Nuclear Reactor Integration with a Reference Oil Refinery

Efforts to identify the most-economic methods to decarbonize several sectors of the U.S. economy are underway. Industrial processes such as crude-oil refining rely heavily on energy-dense and easily stored and transported fossil fuels for powering their operations. Refineries use large amounts of energy, primarily derived from fossil sources to separate crude-oil components, break down heavier hydrocarbons into lighter compounds, remove impurities, reform hydrocarbon molecules, and generate steam and electricity for pumps and compressors and other various auxiliary systems. Crude-oil refining operations such as distillation, cracking, desulfurization, reforming, utilities systems and some offsite facilities collectively account for most of the energy consumption. Other operations such as hydrocracking or hydrotreating also require hydrogen for developing hydrogenation reactions which involve substantial heating to keep the reactors at high-temperature and pressure levels. All heat and energy demands are typically provided by natural gas (NG), oil, or other fuels, which makes refinery industry one of the most-difficult sectors to decarbonize. Nuclear power is a viable and energy-dense source of clean electricity, heat, and hydrogen to provide the large, sustainable energy supply that the refining industry demands. The U.S. Department of Energy’s (DOE’s) Integrated Energy Systems (IES) program is working to perform research and development, design, economic siting, and risk analysis. This state-of-the-art work will enable the first on-site demonstrations and commercial deployments of advanced small modular nuclear reactors (SMNRs) integrated with industries such as chemical production, refining, iron and steel making, and more. IES seeks to demonstrate the ability of advanced nuclear reactors to meet the heat and power demands of these industries while reducing carbon emissions in a sustainable and cost-competitive way. The primary objective of this research effort is to analyze industrial-scale SMNR integration intended to decarbonize refining facilities. The foreseen outcome is the provision of reliable, cost-competitive, and sustainable clean energy, alongside a reduction of carbon emissions. Specifically, the focus of this work lies on meeting the reference facilities’ heat and electricity demands with nuclear power while also supplying clean hydrogen via integrated high-temperature steam electrolysis (HTSE). This report presents a comprehensive technical and economic assessment of the integration of advanced nuclear reactors into a reference refinery, leveraging financial incentives from the Inflation Reduction Act (IRA). The evaluation aims to explore the potential economic benefits and challenges associated with incorporating advanced nuclear reactors into refinery operations, particularly in terms of energy efficiency, economic implications and environmental impact. By examining both the technical feasibility and economic viability, this analysis seeks to identify existing gaps and propose solutions for successful nuclear integration implementation. The findings are intended to provide valuable insights for stakeholders considering the adoption of advanced nuclear reactors in the refining sector. A refinery reference-plant was developed, using an open-source refinery model, Petroleum Refinery Lifecycle Inventory Model (PRELIM) and expert assessment, as a base case for comparison with various nuclear integration options. The capacity of 100 kbd/day (KBD) of heavy crude-oil feed was selected to represent a general coking-type refinery with deep conversion capabilities (incorporating heavy-oil upgrading with FCC, coking, and associated hydrotreating process units), using a heavy crude-oil feed, which represents about 70% of U.S. refineries configurations. A summary of all cases considered in this study is shown in Table 1.

13 HYDRO ENERGY↗

Opportunities and Challenges for Hydrotreating of Catalytic Fast Pyrolysis Oil to Fuels

Catalytic fast pyrolysis (CFP) provides a versatile platform for producing fuels to combat climate change and meet decarbonizing targets. In this contribution, we will discuss the hydroprocessing of CFP oils to a variety of fuels, including sustainable aviation fuel (SAF), diesel, and marine fuel. Both standalone and co-hydroprocessing with petroleum streams will be covered. Hydrotreating CFP oil at temperatures around 400 Degrees Celsius can produce a highly deoxygenated product with oxygen contents below the detection limit. However, the quality of fuel fractions produced has been a problem, manifesting as low octane numbers for the gasoline-range fraction and low cetane numbers for the diesel-range fraction. Incorporating an initial transition zone for hydrogenation during hydrotreating was shown to dramatically increase the diesel fraction cetane number from 24 to 45. A similar approach enabled the production of a cycloalkane-rich SAF fraction meeting key ASTM 4054 guidelines with respect to density, viscosity, heating value, volatility, freeze and flash point. Over 400 hours of hydrotreating for SAF was demonstrated with no signs of catalyst bed fouling, measured by pressure drop over the catalyst bed. Compared to other fuels, marine fuel is unique in that it does not require complete deoxygenation. We investigated the minimum hydrotreating requirements to produce fuel compatible with very low sulfur fuel oil, and the results suggested 30% reduction in hydrotreating costs for this approach. Co-hydroprocessing offers an opportunity to take advantage of refinery infrastructure and economies of scale although the operation is less flexible with respect to operating conditions. Co-hydroprocessing CFP oil with petroleum streams gave efficient deoxygenation at milder conditions (e.g. at temperatures of 320 Degrees Celsius) than required for standalone hydrotreating. Over 90% incorporation of biogenic carbon in the CFP oil was confirmed by carbon-14 analysis. Hydrotreating of CFP oil, whether by standalone or co-processing, can produce a variety of fuel cuts, whose quality can be tailored by changing process conditions. Challenges remain, including long-term catalyst performance and determining CFP oil quality requirements.

09 BIOMASS FUELS↗

Evaluation of Corrosion Susceptibility of Structural Steels in Biomass Derived Pyrolysis Oil

Biomass derived pyrolysis oil is a promising renewable energy source. Due to the variety of biomass feedstocks, the bio-oils could contain a wide range of organic constituents which would provide unique corrosive environments for structural materials. A preliminary work exposed different classes of steels and stainless steels to selected organic constituents of biomass pyrolysis oils and found that corrosion susceptibility, assessed using electrochemical impedance spectroscopy (EIS), was prominent in the steels with Cr lower than 11 wt.%. Although this result suggests stainless steels will resist corrosion by certain organic constituents, it may not be sufficient to predict the corrosion performance in real bio-oils. Therefore, this study attempted electrochemical measurements on Cr-alloyed steels and stainless steels directly exposed to a biomass derived pyrolysis oil. To overcome the low conductivity of bio-oils, a customized Luggin capillary was designed to minimize the ohmic path in bio-oils. The results of this work will be reported.

Jun, Jiheon↗

Technical and Economic Evaluation of the First Ever Polymer Flood Field Pilot to Enhance the Recovery of Heavy Oils on Alaska's North Slope via Machine Assisted History Matching

Polymer flooding has become globally established as a potential enhanced oil recovery method for heavy oils. To determine whether this technology may be useful in developing the substantial heavy oil resources on the Alaska North Slope, a polymer flood field pilot commenced at the Milne Point Unit in August 2018. This study seeks to evaluate the results of the field pilot on a technical and economic basis. A reservoir simulation model is constructed and calibrated to predict the oil recovery performance of the pilot through machine-assisted reservoir simulation techniques. To replicate the early water breakthrough observed during waterflooding, transmissibility contrasts are introduced into the simulation model, forcing viscous fingering effects. In the ensuing polymer flood, these transmissibility contrasts are reduced to replicate the restoration of injection conformance during polymer flooding. Transmissibility contrasts are later reinstated to replicate fracture overextension interpreted in one of the producing wells. The calibrated simulation models produced at each stage of the history matching process are used to forecast oil recovery. These forecasts are used as input for economic analysis, incremental to waterflooding expectations. The simulation forecasts indicate that polymer flooding significantly increases the heavy oil production for this field pilot compared to waterflooding alone, yielding attractive project economics. However, meaningful variations between simulation scenarios demonstrate that a simulation model is only valid for prediction if flow behavior in the reservoir remains consistent with that observed during the history matched period. Critically, this means that a simulation model calibrated for waterflooding may not fully capture the technical and economic benefits of an enhanced oil recovery process such as polymer flooding. Subsequently, the simulation model and economic model are used in conjunction to conduct a sensitivity analysis for polymer flood design parameters, from which recommendations are provided for both the continued operation of the current field pilot and future polymer flood designs. The results demonstrate that a higher polymer concentration can be injected due to the development of fractures in the reservoir. The throughput rate should remain high without exceeding operating constraints. A calculated point-forward polymer utilization parameter demonstrates the decreasing efficiency of the polymer flood at later times in the pattern life. Future projects will benefit from starting polymer injection earlier in the pattern life. A pattern with tighter horizontal well spacing will observe a greater incremental benefit from polymer flooding.

Keith, Cody↗

Electrochemical Corrosion Analysis of Stainless Steels in LALM Pyrolysis Bio-Oil with Organic Corrodents

Pyrolysis bio-oils are corrosive to low alloy steels, e.g., 2.25Cr-1Mo, 5Cr-1Mo, and 9Cr-1Mo grades. To identify the alloys with sufficient bio-oil compatibility, several commercial stainless steels were examined in bio-oil using electrochemical impedance spectroscopy to semi quantitatively assess their corrosion resistance. Low-Ash Low-Moisture (LALM) bio-oil, produced from a forest residue feedstock by the National Renewable Energy Laboratory in Golden, CO, was used as a test liquid for electrochemical impedance spectroscopy measurements. Three organic corrodents, formic acid, catechol, and lactobionic acid, were added into LALM bio-oil to produce test liquids with intentionally increased corrosivity. Corrosion reaction resistance, determined from the impedance data, was used to evaluate the corrosion compatibility of each stainless steel in LALM bio-oil and LALM bio-oil + organic corrodent(s). The results from corrosion reaction resistance indicated that the critical Cr content of stainless steels for corrosion resistance would be greater than 14 wt % if Ni and Mo contents are low but can be as low as 12–13 wt % with appreciable amounts of Ni and Mo.

Jun, Jiheon↗

Emulsified Oil Bio-Barrier to Remediate CEE in the Distal Portion of a Groundwater Plume - 20210

A non-time critical (NTC) removal action (RA) was designed at the Savannah River Site (SRS) to inject an emulsified oil mixture with a bioaugmentation culture to prevent trichloroethylene (TCE) discharging to surface water above maximum contaminant levels (MCLs). The emulsified oil mixture is expected to sequester the TCE and then be broken down into harmless compounds through microbial biodegradation. At 15 locations 8,290 L (2,190 gal) of oil mixture, buffer and chase water were injected into the subsurface creating two bio-barriers. At each location half of the oil mixture was injected, then 2 L (0.528 gal) of an enriched bioaugmentation culture was injected, and then the second half of the oil mixture was injected into the subsurface. Finally, at each location 151 L (40 gal) of buffer mixed with 575 L (200 gal) of dilution water was then injected followed by 1,135 L (300 gal) of chase water. SRS estimates this created two emulsified oil barriers totaling 73 m (240 ft) long, approximately 3 m (10 ft) high and 4.9 m (16 ft) wide in the subsurface. Similar emulsified oil barriers have been effective for 3 to 5 years, and SRS anticipates a similar longevity for these barriers. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Biofuels as Heavy Fuel Oil Substitutes in the Maritime Sector: Findings and Potential Pathways

The United States Department of Energy has commissioned four national laboratories to evaluate the feasibility of biofuels in the maritime sector. This effort is briefly described including the overall project goals, structure and aims. The large two-stroke crosshead engines used to power large merchant vessels were of particular interest since they can burn lower combustion quality fuels relative to four-stroke engines. This characteristic allows for consideration of pyrolysis oils and hydrothermal liquefaction (HTL) oils which are feedstock agnostic and, in the raw state, are more economical compared to distillate drop-in fuels. Pyrolysis and HTL oils are collectively known as bio-intermediates since they require additional processing for use in distillate fuel systems. The key limiting feature is that these bio-intermediate fuels will cause asphaltene precipitation when blended with heavy fuel oils (HFOs) such as very low sulfur fuel oil (VLSFO) unless they are upgraded to remove water and oxygenates. Economics are the key driver at this point in time, and preliminary techno-economic analyses (TEAs) indicate that bio-intermediates have potentially lower cost relative to other biofuels such as biodiesel and renewable diesel. Additionally, life cycle analyses (LCAs) of feedstocks and pathways show the life cycle carbon reduction benefit relative to heavy fuel oils. In addition to TEA and LCA results, we also present on the technical feasibility of these fuels. These studies have focused on the properties of biofuel blends with VLSFO that are critical to the fuel systems of maritime vessels fueled with HFOs. These properties include the compatibility with fuel system metals, viscosity, and blend stability. Aging studies with blends of VLSFO with biodiesel, HTL, and pyrolysis oils are also presented. Future efforts being planned to conduct additional biofuel testing, including the use of biofuels as pilot fuels in zero carbon shipping options fueled with ammonia and methanol, ship-based demonstrations, and bioresource competition studies.

Kass, Michael↗

Using Ionic Liquid Additive to Enhance Lubricating Performance for Low-Viscosity Engine Oil

Energy efficient lubricants are essential for sustainable transportation, and the trend is to develop and implement lower viscosity lubricants with more effective additives. Ionic liquids (ILs) have been reported as candidate additives with superior friction and wear reducing capabilities. Unlike most literature relying on bench-scale testing of simple oil–IL blends, this study produced low-viscosity (SAE 0W-12) fully formulated engine oils using a phosphonium-organophosphate IL as an antiwear additive and evaluated them in both bench-scale tribological testing and full-scale fired engine dynamometer testing. The experimental formulation containing a combination of ZDDP and IL outperformed the formulations using either ZDDP or IL alone, as well as a commercial SAE 0W-20 engine oil in terms of mitigating boundary friction, wear, and contact fatigue-induced micropitting. Furthermore, racing engine dynamometer tests demonstrated 3–4 °C lower oil temperature, 4–5 ft-lbs higher horsepower output, and up to 9.9% better fuel economy for the IL-containing SAE 0W-12 experimental oil compared with selected commercial SAE 5W-30 and 0W-20 engine oils.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Coprocessing Corn Germ Meal for Oil Recovery and Ethanol Production: A Process Model for Lipid-Producing Energy Crops

Efforts to engineer high-productivity crops to accumulate oils in their vegetative tissue present the possibility of expanding biodiesel production. However, processing the new crops for lipid recovery and ethanol production from cell wall saccharides is challenging and expensive. In a previous study using corn germ meal as a model substrate, we reported that liquid hot water (LHW) pretreatment enriched the lipid concentration by 2.2 to 4.2 fold. This study investigated combining oil recovery with ethanol production by extracting oil following LHW and simultaneous saccharification and co-fermentation (SSCF) of the biomass. Corn germ meal was again used to model the oil-bearing energy crops. Pretreated germ meal hydrolysate or solids (160 and 180 °C for 10 min) were fermented, and lipids were extracted from both the spent fermentation whole broth and fermentation solids, which were recovered by centrifugation and convective drying. Lipid contents in spent fermentation solids increased 3.7 to 5.7 fold compared to the beginning germ meal. The highest lipid yield achieved after fermentation was 36.0 mg lipid g−1 raw biomass; the maximum relative amount of triacylglycerol (TAG) was 50.9% of extracted oil. Although the fermentation step increased the lipid concentration of the recovered solids, it did not improve the lipid yields of pretreated biomass and detrimentally affected oil compositions by increasing the relative concentrations of free fatty acids.

09 BIOMASS FUELS↗

Effect of Carboxylic Acids on Corrosion of Type 410 Stainless Steel in Pyrolysis Bio-Oil

Biomass-derived oils are renewable fuel sources and commodity products and are proposed to partially or entirely replace fossil fuels in sectors generally considered difficult to decarbonize such as aviation and maritime propulsion. Bio-oils contain a range of organic compounds with varying functional groups which can lead to polarity-driven phase separation and corrosion of containment materials during processing and storage. Polar compounds, such as organic acids and other oxygenates, are abundant in bio-oils and are considered corrosive to structural alloys, particularly to those with a low-Cr content. To study the corrosion effects of small carboxylic acids present in pyrolysis bio-oils, type 410 stainless steel (SS410) specimens were exposed in bio-oils with varying formic, acetic, propionic and hexanoic acid contents at 50 °C during 48 h exposures. The specific mass change data show a linear increase in mass loss with increasing formic acid concentration. Interestingly, a mild corrosion inhibition effect on the corrosion of SS410 specimens was observed with the addition of acetic, propionic and hexanoic acids in the bio-oil.

09 BIOMASS FUELS↗

Quantitative Low-Field 19 F Nuclear Magnetic Resonance Analysis of Carbonyl Groups in Pyrolysis Oils

Pyrolysis bio-oils, one of the products of lignocellulosic biomass pyrolysis, have the potential to be widely used as fuels. The chemical composition of bio-oils is very complicated as they contain hundreds, if not thousands, of different, mostly oxygen-containing, compounds with a wide distribution of physical properties, chemical structures, and concentrations. Detailed knowledge of bio-oil composition is crucial for optimizing both the pyrolysis processes and for any subsequent upgrading into a more viable fuel resource. Here we report the successful use of low-field, or benchtop, nuclear magnetic resonance (NMR) spectrometers in the analysis of pyrolysis oils. Pyrolysis oils from four different feedstocks were derivatized and analyzed using 19 F NMR techniques. The NMR results compare favorably with titrations for total carbonyl content. In addition, the benchtop NMR spectrometer proves able to reveal key spectral features, thus allowing the quantification of different carbonyl groups, such as aldehydes, ketones and quinones. Benchtop NMR spectrometers are typically compact, cheaper than their superconducting counterparts and do not require cryogens. Their use will make NMR analysis of pyrolysis oils easier and more accessible to a wide range of different potential users.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗