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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Mixing Controlled Compression Ignition Combustion

Mixing controlled compression ignition or diesel engines are highly efficient and are likely to continue to be the primary means for movement of goods for many years to come. Low-carbon biofuels have the potential to significantly reduce the carbon footprint of diesel combustion and could potentially have advantageous properties for combustion such as high cetane number and reduced engine out particle emissions. In this study, we developed a list of potential biomass-derived diesel blendstocks. An online database of properties and characteristics of these bioblendstocks was populated with data. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a bioblendstock met the basic requirements for handling in the diesel distribution system and use as a blend with conventional diesel. Criteria included cetane number =40, flashpoint =52 degrees C, and boiling point or final boiling point <338 degrees C. Blendstocks needed to be soluble in diesel fuel, have a toxicity no worse than conventional diesel, and not be corrosive. Additionally, cloud point or freezing point below 0 degrees C was required. This screening produced a list of 27 potential bioblendstocks. Of these candidates, 13 were available commercially or could be synthesized by biofuels production researchers and included 11 nominally pure components and two mixtures. These 13 candidates were then subjected to further study based on how they impact fuel properties upon blending. Blend properties included cetane number, lubricity, conductivity, oxidation stability and viscosity. Results indicate that all thirteen candidates can meet the basic requirements for diesel fuel blending and are likely to reduce particle emissions from diesel combustion.

09 BIOMASS FUELS↗
DOE OSTI2021

Potential Economic Values of Low-Vapor-Pressure Gasoline-Range Bio-Blendstocks: Property Estimation, and Blending Optimization

Adding non-traditional blendstocks derived from biomass into gasoline has gained renewed interest since it will reduce greenhouse gas emissions and potentially enhance fuel properties and boost engine efficiencies. A competitive bio-blendstock candidate should have either lower prices or superior properties or both relative to conventional gasoline blending components. Gasoline is a mixture of hundreds compounds specified by properties rather than compositions. The addition of bio-blendstocks, most likely oxygenates, will modify the property mixing rules due to the non-ideal interactions between polar and nonpolar components. This paper presents an equation-of-state-based model for predicting Reid vapor pressure, reduced order non-linear property blending models for computing key properties of final gasoline products, and a blending optimization approach to identify key economic drivers. This paper also evaluates the economic values of bio-blendstocks to petroleum refiners using those models. In additional to ethanol, six low-vapor-pressure bio-blendstock candidates were evaluated: i-propanol, n-propanol, i-butanol, diisobutylene, cyclopentanone, and a mixture of furans. Reid vapor pressure, distillation temperatures, and octane numbers were identified as the key economic drivers of adding bio-blendstock. The economic values of those bio-blendstocks range from 2.22 to 4.00 US dollar per gasoline gallon equivalent in 2013 to 2017 5-year averaged price basis. The bio-blendstocks with higher octane numbers may have higher economic values. The uncertainties in property predictions may lead to roughly 15% deviation in the economic value evaluation.

Jiang, Yuan↗
DOE OSTI2019

Estimation of the Fuel Efficiency Potential of Six Gasoline Blendstocks Identified by the U.S. Department of Energy’s Co-Optimization of Fuels and Engines Program

Six blendstocks identified by the Co-Optimization of Fuels & Engines Program were used to prepare fuel blends using a fixed blendstock for oxygenate blending and a target RON of 97. The blendstocks included ethanol, n-propanol, isopropanol, isobutanol, diisobutylene, and a bioreformate surrogate. The blends were analyzed and used to establish interaction factors for a non-linear molar blending model that was used to predict RON and MON of volumetric blends of the blendstocks up to 35 vol%. Projections of efficiency increase, volumetric fuel economy increase, and tailpipe CO2 emissions decrease were produced using two different estimation techniques to evaluate the potential benefits of the blendstocks. Ethanol was projected to provide the greatest benefits in efficiency and tailpipe CO2 emissions, but at intermediate levels of volumetric fuel economy increase over a smaller range of blends than other blendstocks. A bioreformate surrogate blendstock was projected to provide the greatest increase in volumetric fuel economy and the lowest increase in efficiency. Tailpipe CO2 emissions for blends of the bioreformate surrogate were higher at all blend levels compared to the baseline E10 fuel.

02 PETROLEUM↗
DOE OSTI2019

Technoeconomic and Life-Cycle Analysis of Single-Step Catalytic Conversion of Wet Ethanol into Fungible Fuel Blendstocks

Technoeconomic and life-cycle analyses are presented for catalytic conversion of ethanol to fungible hydrocarbon fuel blendstocks, informed by advances in catalyst and process development. Whereas prior work toward this end focused on 3-step processes featuring dehydration, oligomerization, and hydrogenation, the consolidated alcohol dehydration and oligomerization (CADO) approach described here results in 1-step conversion of wet ethanol vapor (40 wt% in water) to hydrocarbons and water over a metal-modified zeolite catalyst. A development project increased liquid hydrocarbon yields from 36% of theoretical to >80%, reduced catalyst cost by an order of magnitude, scaled up the process by 300-fold, and reduced projected costs of ethanol conversion 12-fold. Current CADO products conform most closely to gasoline blendstocks, but can be blended with jet fuel at low levels today, and could potentially be blended at higher levels in the future. Operating plus annualized capital costs for conversion of wet ethanol to fungible blendstocks are estimated at $2.00/GJ for CADO today and $1.44/GJ in the future, similar to the unit energy cost of producing anhydrous ethanol from wet ethanol ($1.46/GJ). Including the cost of ethanol from either corn or future cellulosic biomass but not production incentives, projected minimum selling prices for fungible blendstocks produced via CADO are competitive with conventional jet fuel when oil is $100 per barrel but not at $60 per barrel. However, with existing production incentives, the projected minimum blendstock selling price is competitive with oil at $60 per barrel. Life-cycle greenhouse gas emission reductions for CADO-derived hydrocarbon blendstocks closely follow those for the ethanol feedstock.

09 BIOMASS FUELS↗
DOE OSTI2022

Production and Catalytic Upgrading of 2,3-Butanediol Fermentation Broth into Sustainable Aviation Fuel Blendstock and Fuel Properties Measurement

With the increasing demand for sustainable supplies of aviation fuel and need to address climate change, new conversion technologies are needed to efficiently process biomass, produce high quality jet fuel blendstock, and meet carbon emission targets. This study demonstrates the synthesis, conditioning, and catalytic upgrading of 2,3-butanediol (BDO) fermentation broth into a jet fuel blendstock candidate. A high-titer 2,3-BDO fermentation broth (i.e., ~90 g/L) was produced at a 100-L scale and pretreated via nanofiltration to decrease the impurities level in the broth from 4.6 to 0.6 wt%. A novel process for catalytic upgrading of aqueous 2,3-BDO into a jet fuel blendstock candidate was developed, and each step was efficiently demonstrated. The catalytic steps include 1) 2,3-BDO dehydration into methyl ethyl ketone (MEK) over AlPO4, 2) MEK conversion into olefins over Zn1Zr10Ox, 3) oligomerization of olefins over a zeolite beta, and 4) hydrogenation over platinum/carbon. Both the model feed and real 2,3-BDO fermentation broth were tested for upgrading 2,3-BDO to MEK. With the real feed, a continuous loss of conversion (i.e., >50% loss over ~140 h time-on-stream [TOS]) was partly attributed to reversible deactivation from coking species. However, the conversion remained stable with the model feed, which demonstrates the efficiency of the first step for converting aqueous 2,3-BDO (10 wt% in water). For upgrading MEK to olefins, high selectivity to olefins (i.e., 82.5%) was obtained at high conversion levels (i.e., 93-98%) with stable conditions being achieved for > 70-hours TOS. Oligomerization of light olefins, which was demonstrated for > 270 h TOS, mainly led to the formation of dimers (C8-10) and trimers (C13-14). The oligomerized product was hydrogenated and distilled to recover the jet fraction (35 mass% or 40.9% carbon based yield), which consists mostly of desired isoalkanes (31.7 wt%), n-alkanes (24.5 wt%), and cycloalkanes (29.6 wt%). While some improvement is still needed to meet ASTM D7566 specifications for viscosity and final boiling point temperature, freezing point, density, aromatics content, and sulfur content of the jet blendstock candidate were within acceptable ranges, thus highlighting the potential of this process for production of jet fuel blendstock.

ADVANCED PROPULSION SYSTEMS,BIOMASS FUELS↗
DOE OSTI2020

Toxicology and Biodegradability of Blendstocks for Mixing Controlled Compression Ignition Combustion: Literature Review of Available Data

The goal of the U.S. Department of Energy’s Co-Optima project is to develop an understanding of potential biomass-derived blendstocks for use in the transportation sector. This report documents the estimated environmental and toxicological impact of potential bioblendstocks for mixing controlled compression ignition (MCCI) engines. The candidate molecules were: 2-nonanol; n-undecane; 2,6,10-trimethyldodecane; 5-ethyl-4-propylnonane; hexylhexanoate; methyldecanoate; dibutoxymethane; 4-butoxyheptane; dipentylether; renewable diesel; and soy biodiesel. To provide a robust comparison, diesel surrogate molecules were also considered: α-methylnaphthalene; decahydronaphthalene; 2,2,4,4,6,8,8-heptamethylnonane; n-butylcyclohexane; n-hexadecane; tetralin; and n-dodecylbenzene. The intent of this work was not to provide absolute answers and remove any molecules from consideration, but to provide more robust data for each molecule that can be used in subsequent evaluations. Little literature data was available for many of the molecules, both potential blendstocks and diesel surrogates, so a quantitative structural activity relationship (QSAR) approach was used to provide input into the relevant models. This assessment included an evaluation of compartment partitioning in the event of an accidental chemical spill, fate and transport indicators, estimated biodegradability, and human and environmental toxicology. The higher molecular weight and longer hydrocarbon chain lengths of these MCCI molecules reduce water solubility and mobility. Generally, the oxygenated molecules improved biodegradability metrics. The hydrocarbons farnesane and 5-Et-4-PrNonane are not predicted to be biodegradable. Human acute toxicity was found to be slightly to non-toxic for the MCCI blendstocks and the diesel surrogates. 2-Nonanol, undecane, MeDecanoate, dibutoxymethane, and dipentylether were likely developmental toxicants. Although poorly water soluble, all the compounds, whether Co-Optima blendstocks or diesel surrogates, showed significant toxicity to D. magna. The oxygenated blendstocks were less likely to bioaccumulate than the non-oxygenated blendstocks, which behaved similar to the diesel surrogates. Overall, this predicted analysis showed that the MCCI blendstocks are very similar to their diesel counterparts. No significant showstoppers were found that would indicate concern moving forward with additional research into these potential fuels. The results presented were based solely on predictive models and serve to provide information going forward for continued evaluation of these molecules.

09 BIOMASS FUELS↗
DOE OSTI2019

Toxicology and Biodegradability of Tier Three Gasoline Blendstocks: Literature Review of Available Data

This study provides framework for decision makers to more fully evaluate the toxicology and biodegradability of the tier three gasoline blendstocks developed under Co-Optima. These Co-Optima blendstocks were compared to gasoline surrogate compounds, providing guidance for future consideration as the project progresses. Due to the complexity of the subject area, all compounds were considered only in their pure form, not as complex mixtures with gasoline, which was outside the scope of this study. The metrics applied to the blendstocks were environmental transport and fate, environmental and human health toxicity, and environmental regulatory framework. The blendstocks (cyclopentanone; diisobutylene; 2-methylfuran; 2,5-dimethylfuran; isobutanol; ethanol; and isopropanol) presented limited human toxicity based on the information available. All the blendstocks migrated primarily into air or water, with little mobility between these compartments. Coupled with aerobic and/or anaerobic biodegradability, long term environmental persistence is unlikely, with the only exception being diisobutylene, which was not biodegradable. Additional work should focus on the environmental impact of these blendstocks in complex mixtures, such as gasoline, which will represent more real world scenarios.

09 BIOMASS FUELS↗
DOE OSTI2021

Production, fuel properties and combustion testing of an iso-olefins blendstock for modern vehicles

With the increasing pressure to decarbonize the transportation sector, exploring strategies that can reduce emissions from light-duty vehicles (LDV) has become critical. Bioblendstocks that allow for higher engine efficiency and fuel economy could complement vehicle electrification and help reach carbon neutrality by 2050. In this context, the potential of a mixture of iso-olefins as a bioblendstock was investigated for multimode boosted spark-ignition (SI)/advanced compression ignition (ACI) engine operation designed to achieve higher overall vehicle fuel economy. By establishing the relationship between the molecular structure of iso-olefins and research octane number (RON), octane sensitivity (S) (i.e., the difference between RON and motor octane number [MON]), and phi-sensitivity a dimethyl-hexenes rich olefins mixture (DMHROM) was identified as a preferred blendstock for SI/ACI combustion engines. Here, a pathway for DMHROM production from biomass-derived ethanol was developed and scaled up. More than 1 gallon of DMHROM blendstock was produced for fuel properties assessment including engine testing. Measurements in a Cooperative Fuel Research Engine showed that the DMHROM blendstock possesses a RON of 94 and S of 13.5, and blends synergistically. Rapid compression machine tests coupled with single-cylinder gasoline direct injection engine measurements demonstrated the 20 vol.% DMHROM blend has higher phi-sensitivity than an olefin-free gasoline base fuel and a typical California Reformulated Gasoline Blendstock for Oxygenate Blending (CARBOB) gasoline fuel. These results demonstrate the potential of DMHROM for improving gasoline fuel performance and quality for operation under ACI conditions. The effectiveness of the aftertreatment system in mitigating emissions was verified and showed that the pure DMHROM blendstock and 20 vol.% blend would not increase non-methane organic gases, NO x , and carbon monoxide (CO) emissions. The DMHROM blendstock was found to slightly decrease sooting tendency when added to a gasoline-base fuel (i.e., ~6% reduction at 20 vol.% blending level). Oxidation stability and lubricant compatibility were both confirmed for the 20 vol.% blend. Overall, these results demonstrate that dimethyl-hexenes have potential for improving engine efficiency and fuel economy while meeting emissions regulations and ASTM specifications for gasoline fuel.

09 BIOMASS FUELS↗
DOE OSTI2022

A 100+ RON Gasoline Blendstock for High Efficiency, Low Emission Vehicles Engines - CRADA 493 (Final Report)

This study aimed at demonstrating production of a 100+RON gasoline fraction from a linear olefins feedstock to help improve further the viability and flexibility of the Pacific Northwest National Laboratory/ LanzaTech alcohol-to-jet (ATJ) patented process that converts ethanol from LanzaTech’s syngas fermentation process to low aromatic jet-range iso-paraffins. To achieve a high RON gasoline and ultimately a 100+RON, the technical approach consisted of converting the linear olefins into an iso-olefins rich mixture and then oligomerizing the iso-olefins rich mixture into high RON compounds in a single bed loaded with an acid catalyst that allows conversion at low reaction temperature. Three families of acid catalysts labeled as type A, B and C were investigated for the single-bed conversion of linear olefins into high RON gasoline range compounds. The effects of the nature of the catalyst, acid sites concentration and operating conditions were investigated. Fuel properties measurements and engine testing were conducted for the most promising catalyst. For type A catalysts, we demonstrated that the conversion increases with the increase of the Brönsted acid site concentration and that lower reaction temperature favors the formation of desired highly branched compounds. The highest dRON obtained with type A catalyst was equal to 94 (from NMR and IQT). Type B catalysts appear very effective for producing dimethyl-olefins compounds when operating at low reaction temperature (i.e., < 100°C). The highest dRON obtained with type B catalyst was equal to 92. The results suggest that type B catalysts are less favorable to internal conversion of linear olefins into iso-olefins compared to type A catalysts which leads to the formation of a gasoline blendstock with a lower dRON. A Type C catalyst that is less commonly used for production of gasoline range compounds from linear olefins was investigated due to its ability to favor conversion of linear olefins into iso-olefins. Compared to type A and type B catalyst, type C favors the formation of highly branched compounds (i.e., with 3+ methyl groups) in the gasoline range. Indeed, a gasoline blendstock containing about 33 wt.% of highly branched compounds was produced with type C catalyst while maintaining a high linear olefins conversion (i.e., 70%). A large quantity of this gasoline blendstock was produced and fuel properties measurements including engine testing for Research Octane Number (RON), Motor Octane Number (MON) and octane sensitivity (S) were conducted. A high RON = 97, MON = 82.7, S =14.3, AKI = 90 and HoV = 334.1kJ/kg were measured. While a RON of 100 was not achieved, the fuel properties of the gasoline blendstock are very acceptable as compared to current premium gasoline. Overall, these results highlight the potential for producing a high RON/ premium gasoline blendstock starting from a linear olefins feedstock.

02 PETROLEUM↗
DOE OSTI2021

Overview and technology opportunities for thermochemically-produced bio-blendstocks

Global demand for transportation fuels is projected to increase 40% by 2040, and biomass-derived fuels (biofuels) play a crucial role in substituting fossil fuels and mitigating greenhouse gas emissions. Currently, biofuels are mainly consumed as blendstocks combined with petroleum-based fuels, and effective conversion technologies can address the quality challenges for offering standalone biofuels. Thermochemical conversion process is one of the most promising pathways among existing technologies for biofuel production. However, the major barriers are unwanted characteristics (e.g., thermal instability) of intermediate products, such as bio-oil, and required upgrading treatments for producing compatible fuels. Here, this study highlights the merits and critical challenges of thermochemical conversion and physicochemical upgrading technologies for bio-blendstock production from lignocellulosic biomass. The novelty of this study lies in potential directions for future research through both critical and systematic literature reviews, and the proposed intensified process for lignocellulosic-based fuel blendstocks production. It is concluded that recovery and fractionation strategies (e.g., quenching and stripping) can maximize process yields and add values in the efficient conversion pathways. Effective quenching can stop secondary free radical reactions and improve liquid yields over gas and solid yields. Stripping process can improve process yield, catalyst lifespan, and thermal stability. It is further concluded that physicochemical treatments are not as effective as thermochemical treatments, but have advantages of mild operating conditions and potential for integrated solutions in conjunction with other treatments.

09 BIOMASS FUELS↗
DOE OSTI2019

Elastomer Swell Behavior in 1-Propanol, Diisobutylene, Cyclopentanone, and a Furan Mixture Blended in E10 and a Blendstock for Oxygenate Blending (BOB)

The compatibility of four potential bio-derived blendstock molecules with infrastructure elastomers was determined by measuring the volume change following exposure. The blendstock molecules included 1-propanol, diisobutylene, cyclopentanone, and a furan mixture. The elastomers included two fluorocarbons, six nitrile rubbers (NBRs), and one each of fluorosilicone, neoprene, polyurethane, and silicone. The elastomers were exposed to the fuel molecules as blends ranging from 0 to 30 vol.% in both a blendstock for oxygenate blending (BOB) formulation and an E10 fuel. Silicone exhibited excessive swelling in each test fuel, while the other elastomers showed good compatibility (low swell) with diisobutylene, 1-propanol, and the furan mixture when BOB was used as the base fuel. The E10 base fuel produced high (>30%) swell in neoprene, polyurethane, and some nitrile rubbers. In most cases diisobutylene produced the least amount of volume expansion. In contrast, the addition of cyclopentanone produced unacceptably high swelling in each elastomer and is not considered suitable for use with these fuels. Analysis of the results showed that the swelling behavior is predominantly due to the polarity of the elastomer and test fuels.

03 NATURAL GAS↗
DOE OSTI2023

2.3.4.104 - Lignin Conversion to Sustainable Aviation Fuel Blendstocks

The Lignin Conversion to Sustainable Aviation Fuel Blendstocks (LigSAF) project focuses on the conversion of lignin-rich streams to deoxygenated aromatic and cycloalkane blendstocks in the jet fuel range. This work is done in close collaboration with the BETO-funded Lignin-First Biorefinery Development project and industrial scale-up partners, and the work is closely guided by analysis to develop cost-effective and sustainable routes to produce lignin-based SAF blendstocks. To date, we have demonstrated the continuous catalytic conversion of a lignin oil from poplar to deoxygenated aromatic products at -85% C-mol yield. This hydrodeoxygenation process uses a stable, earth-abundant catalyst and requires no solvent. We have also established a baseline process model and associated techno-economic analysis and life cycle assessment that together demonstrate the potential to achieve cost parity with fossil carbon-based jet fuel at -70% reduction in greenhouse gas emissions. Current work is focused on expanding the slate of feedstocks for hydrodeoxygenation to include lignin oils from softwoods, agricultural residues, and grasses as well as from hydrolysis lignin substrates from biochemical conversion and pulp-and-paper processes. We are also undertaking catalyst development efforts to tune the reaction selectivity from aromatic compounds to cycloalkanes. Lastly, we are investigating reaction engineering strategies to slurry solids for hydrodeoxygenation reactions.

aromatics↗
DOE OSTI2019

Techno-economic analysis and life-cycle greenhouse gas mitigation cost of five routes to bio-jet fuel blendstocks

Decarbonizing the air transportation sector remains one of the most challenging hurdles to mitigating climate change. Lignocellulosic biomass-derived jet fuel blendstocks can contribute to the shift toward renewable, low-carbon energy sources for aircrafts. Producing these renewable jet fuel molecules from biomass requires advanced pathways with the potential for efficient and affordable conversion routes. Here, this paper presents a detailed techno-economic analysis and sensitivity analysis, including estimated minimum selling price (MSP), and life-cycle greenhouse gas (GHG) mitigation costs for five routes to four potential bio-jet fuel molecules – limonane via limonene, limonane via 1,8-cineole, tetrahydromethylcyclopentadiene dimer (RJ-4), bisabolane, and epi-isozizaane. The simulated biorefineries utilize biomass sorghum and an integrated high-gravity ionic liquid-based biomass deconstruction process. We present results reflecting the current state of the technology and potential future scenarios with improved yields. Among the conversion pathways and the fuel molecules evaluated in this study, limonane, bisabolane, and epi-isozizaane could reach an MSP of 0.73–0.91 dollars per L-Jet A (2.75–3.45 dollars per gal-Jet A) in optimized future cases, without a hypothetical lignin-derived co-product. RJ-4 requires a more costly upgrading process and catalysts, resulting in a comparatively higher MSP (1.33 dollars per L-Jet A or 5.04 dollars per gal-jet A). Based on the GHG footprints of each fuel, the minimum achievable carbon mitigation cost relative to conventional Jet-A is 29 dollars per metric ton CO 2e , which is just under double the current cap-and-trade market price in California. In the absence of any policy support, the economics could be improved through high-value uses for lignin. To reach a target selling price of 0.66 dollars per L-Jet A (2.50 dollars per gal), lignin-derived products would need to be sold for at least 1.9 dollars per kg. However, the higher energy density of these bio-based blendstocks offers valuable improvements in aircraft efficiency/range; we find that commercial airlines may be willing to pay a 4–14 cent per L premium for these bio-jet fuels. In conclusion, our results highlight the need for improvements beyond currently-reported yields for the biologically produced intermediates, identification of ideal microbial hosts, selection of metabolic pathways to achieve competitive production costs, and a focus on fuels with attractive properties that increase their value.

09 BIOMASS FUELS↗
DOE OSTI2018

Corrosion Potential of Selected Bio-blendstock Fuel Candidates for Boosted Spark Ignited Engines

Eight bio-blendstock fuel candidates for boosted spark ignited engines were evaluated for their susceptibility to corrode infrastructure metals. These candidates included five alcohols (methanol, ethanol, isobutanol, n-propanol, and isopropanol), diisobutylene, mixed furans, and aromatics. Methanol was also added to the list for comparison. These molecules are not corrosive to metals since they cannot dissociate into ions and anions. However, the addition of contaminants and a separate water phase may facilitate corrosion due to phenomena associated with the formation of ions and anions (from key contaminants), differential aeration cell (due to dissolved oxygen), and microbial-induced corrosion. A literature review was conducted to determine the influence of these phenomena on corrosion for the nine fuel candidates. In addition, the oxygen solubility of each fuel type was determined to ascertain their relative influence on forming and enhancing a differential aeration cell. Of the fuel candidates, only the alcohols are water soluble, and therefore have an opportunity to cause corrosion. However, differential aeration cells, by themselves have not been shown to contribute to corrosion. Other factors, such as galvanic coupling and/or crevice regions are necessary to promote corrosion in laboratory conditions. However, differential aeration as a corrosion mechanism has not been established in the field. Likewise, microbial-induced corrosion is another known corrosion pathway that has yet to be positively identified for blends of the fuel candidates with gasoline. In summary, corrosion is not anticipated with any of the bio-blendstock candidates with infrastructure metals.

09 BIOMASS FUELS↗
DOE OSTI2021

100+ RON Gasoline Blendstock for High Efficiency, Low Emissions (CRADA 493)

The PNNL/LanzaTech alcohol-to-Jet (ATJ) patented process converts ethanol from LanzaTech’s syngas fermentation process to low aromatic jet-range isoparaffins. Compounds are generated across a wide boiling range by the process. The project goal is to improve the viability of the ATJ process by increasing the RON of the gasoline fraction and determine what types of engines and vehicles can be fueled with this gasoline. PNNL experts’ team will investigate the impact of the process conditions and catalysts formulation on the blendstock composition in relation with the fuel properties. Co-optima capabilities for fuel properties measurements will be leveraged to assess the potential engines/ vehicles applications of the produced blendstock. A techno-economic-analysis will be conducted to assess the commercial viability of the process for generating a high RON gasoline-range fuel.

09 BIOMASS FUELS↗
DOE OSTI2019

Top Ten Blendstocks For Turbocharged Gasoline Engines: Bioblendstocks With Potential to Deliver the for Highest Engine Efficiency

More efficient engines enabled by better fuels derived from biomass could increase the fuel economy of the light duty (LD) fleet by 10% over current technology and planned developments. This report identifies top LD boosted spark ignition (BSI) biofuel candidates for further development and commercialization identified using a fuel property basis. The BSI merit function was used to evaluate the performance of candidate bio-blendstocks in improving engine efficiency. This report is aimed at biofuel researchers looking to better understand the efficiency implications of biofuels under development, as well as engine researchers who are interested in future biofuels with properties that enable more efficient engine design and operation.

09 BIOMASS FUELS↗
DOE OSTI2022

Blended fuel property analysis of butyl-exchanged polyoxymethylene ethers as renewable diesel blendstocks

Methyl-terminated polyoxymethylene ethers (MM-POMEs), having the formula CH 3 O-(CH 2 O)n-CH 3 (n = 3-6), are a class of oxygenates with desirable diesel-like fuel properties including high cetane number and low soot formation. However, their low energy density and high water-solubility present barriers to their adoption. Both concerns were recently addressed by our research group by synthesizing a mixture of POME structures having butyl end-groups and n = 1-6, termed B*POME1-6. B*POME1-6 maintained the advantageous properties of the parent MM-POMEs, and exhibited improved energy density and most notably, dramatically decreased water solubility. For evaluation against a set of criteria for a blended diesel blendstock, a 20 vol% blend of B*POME1-6 with a base diesel fuel was investigated here. Oxidation stability, cetane number, sooting tendency, lubricity and conductivity were improved in the B*POME1-6 blend compared with the base diesel, while also maintaining the flash point, cloud point, energy density, viscosity, and boiling point requirements. The B*POME1-6 product demonstrated a synergistic blending behavior at 10 vol% and a linear blending behavior at 20-30 vol% blends, in agreement with similar POME blends at comparable blend levels. Finally, common environmental and toxicity models performed on B*POME1-6 component molecules suggested they have a greater propensity to partition into the water compartment compared to a common diesel surrogate, but with a lower tendency to bioaccumulate.

33 ADVANCED PROPULSION SYSTEMS↗