Bioenergy Technologies Office Research Articles

Scale Up and Coupling of the MOXIE Solid Oxide Electrolyzer for Both Terrestrial and Space Applications

The Mars Oxygen ISRU Experiment (MOXIE) is a first of its kind demonstration of in-situ resource utilization technology to produce propellant and breathable oxygen from the Mars ambient carbon dioxide. The use of Lunar and Martian resources represents a significant opportunity to reduce the cost of launch from Earth, enabling propellant production for space refueling, and allowing for life support of manned missions to the Lunar and Martian surfaces.Since developing the Solid OXide Electrolysis (SOXE) stacks for the Mars 2020 MOXIE program in 2017, the OxEon team has made significant advancements in scale and capabilities of the SOXE stack technology used in that system. Newer variants have a five-fold larger cell area and a 6.5-fold increase in cells per stack, for a stack scaled 33-times the 0.5% scale of the device in MOXIE. Six of these OxEon mission-scale SOXE stacks will produce 30 tons of propellant oxygen to fuel a Mars Ascent Vehicle (MAV) in the 19-month window between landing an unfueled MAV pre-supply mission and the next launch opportunity for the first crewed Mars Mission, meeting target requirements for a return mission. OxEon has built and demonstrated systems with mission-scale stacks for both Lunar and Martian applications. A system for the production of propellant H2 and O2 from Lunar ice was successfully tested in a cryo-vac chamber at the Colorado School of Mines in 2022. Another mission-scale demonstration system is scheduled to demonstrate production of O2 and methane from Martian H2O and atmospheric CO2 at Jet Propulsion Laboratory in 2022.In addition to SOXE/SOFC systems, the OxEon technology portfolio also consists of a low energy plasma reformer capable of producing sygnas from a variety of hydrocarbons and a modular-scale Fischer-Tropsch reactor for the production of liquid fuels from syngas. These technologies allow OxEon to provide a wide range of terrestrial energy solutions. A DOE Bioenergy Technologies Office (BETO) funded system is currently being fabricated to demonstrate the conversion of both CO2 and CH4 in anaerobic digester gas to liquid transportation fuels. This will be accomplished using an SOEC system to convert steam and CO2 to synthesis gas. OxEon’s plasma reformer will be used to convert methane to synthesis gas, using the plasma to catalyze the reaction of methane with steam and oxygen, supplied in part by the byproduct oxygen from the electrolysis system. The syngas from the plasma reformer and electrolysis systems are then combined to produce liquid fuels in the Fischer-Tropsch (FT) reactor. Figure 1

Mono-material product design with bio-based, circular, and biodegradable polymers

Mono-material product design with bio-based, circular, and biodegradable polymers

Case study of autocatalysis reactions on tetra hybrid binary nanofluid flow via Riga wedge: Biofuel thermal application

Ethanol and biodiesel, which both belong to the first generation of biofuel technology, are the two most popular forms of biofuels now in use. In order to create next-generation biofuels using waste, cellulosic biomass, and algae-based resources, the Bioenergy Technologies Office (BETO) is working with business. The present article is designed to study the effect of tetra hybrid nanoparticles with the utilization of the novel Hamilton and Crosser model and catalytic reaction on binary fluid with the consideration of ethanol biofuel as a base fluid. Ethanol comprising tetra hybrid nanoparticles and heterogeneous catalytic reaction amplifies thermal conductivity and significantly increases brake thermal efficiency and reduces brake-specific fuel consumption in diesel engines. Therefore, the aim of this article is a theoretical checkup that is related to heat and mass transport of biofuel flow considering binary fluid accompanied with autocatalysis reaction and novel tetra hybrid nanoparticles on biofluid flow subjected to a Riga wedge. Transportation of heat via nonuniform heat source/sink, thermal radiation, and thermal conductivity are in our consideration. The mathematics of the assumed problem generates the system of non-linear partial differential equations from basic equations of momentum, energy, and mass. The usage of non-dimensional variables gave a system of non-linear ODEs with boundary conditions which are further dealt with in the Lobatto111A scheme. The results are obtained for stretching/shrinking wedge with several parameters. From obtained results, it is observed that the velocity field diminishes owing to magnification in Weissenberg number and Casson fluid parameter. The temperature field diminishes by amplifying heat generation, thermal radiation, and variable thermal conductivity parameter. Concentration distribution escalates by rising homogeneous reaction parameters.

Development of integrated screening, cultivar optimization, and verification research (DISCOVR): A coordinated research-driven approach to improve microalgal productivity, composition, and culture stability for commercially viable biofuels production

To address major knowledge gaps and barriers to the commercial development of algal biomass for biofuels and co-products, a collaborative consortium, Development of Integrated Screening, Cultivar Optimization, and Verification Research (DISCOVR), was established in 2016. Funded by the U.S. Department of Energy (DOE) Bioenergy Technologies Office (BETO), this consortium constitutes a partnership between four DOE national laboratories - Pacific Northwest National Laboratory (PNNL), Los Alamos National Laboratory (LANL), the National Renewable Energy Laboratory (NREL), and Sandia National Laboratories (SNL) - and the Arizona Center for Algae Technology and Innovation (AzCATI) at Arizona State University.To address the barriers of strain selection for achieving high seasonal productivities with a suitable composition and culture resilience, a tiered strain down-selection pipeline is implemented. At Tier I, the temperature and salinity tolerance of strains is determined in flask cultures; at Tier II, the areal biomass productivity and composition is determined in climate-simulation photobioreactors; at Tier III, the productivity and culture stability are determined in outdoor raceways. The top performing strains move forward to long-term testing at the algae testbed site at AzCATI to generate annual biomass productivity data.Concurrent to the strain down-selection in the DISCOVR pipeline, hypotheses for increasing biomass productivity, shifting biomass composition to enhance intrinsic value, and improving culture stability and resistance to pests are also tested. Techno-economic analyses are carried out to determine whether promising findings from laboratory studies or proposed modifications in outdoor pond cultivation conditions translate into reductions in the minimum biomass selling price (MBSP). In the three years following the launch of DISCOVR, annual biomass productivity has increased from 11.7 to 17.6 g m−2 day−1, resulting in an MBSP decrease from 824 to 611 $ ton−1.

Effect of Formic and Acetic Acids on Corrosion of 410 Stainless Steel in Bio-Oils

Biomass derived oils, made from decomposition and conversion of biomass feedstocks, are proposed as alternative sustainable fuels and potential precursors to valuable chemicals. Bio-oils are produced using different approaches including hydrothermal liquefaction and fast pyrolysis of biomass feedstocks. The composition of bio-oils varies depending on the biomass source as well as on the production method. Bio-oils also contain various functional groups including carboxyl, ketone, aldehyde, phenol etc. Among the functional groups, compounds containing oxygenated species such as carboxyl, phenol and ketone groups can be particularly corrosive to metallic and polymeric materials used for transportation, production, and storage of bio-oils. Formic and acetic acids are some of the most prevalent carboxylic acids present in fast-pyrolysis bio-oils and pose a concern for corrosion of metal alloys. In the present study, we varied the amounts of carboxylic acids in a forest residue fast pyrolysis bio-oil to assess their effects on corrosion of type 410 stainless steel (410SS). To study the effect of formic and acetic acids on corrosion in bio-oils, we exposed 410SS specimens in FR3 (forest residue, fast pyrolysis bio-oil) in short term (48 hour), mild temperature (50 °C) exposures. 410SS specimens were polished, weighed and exposed to fast pyrolysis bio-oil (FR3) with baseline modified total acid number (AMTAN) value of 50.1 mg of KOH per gram of bio-oil. Using a piece of Teflon string, specimens were suspended in approximately 25 g of bio-oil at 50 °C for 48 hours. The oil samples were then spiked with either formic or acetic acids. Capillary electrophoresis was used to quantify formic and acetic acids present in the bio-oil. The area under the curves were determined and correlated to concentration of each specie using standards. Electrochemical Impedance Spectroscopy (EIS) was also performed to investigate corrosion behavior of 410SS in FR3 bio-oil at room temperature. A miniature glass cell & Luggin capillary to minimize ohmic drop within the bio-oil phase was utilized. Reference mercury sulfate electrode and platinum mesh counter electrode were used for EIS measurements.The results of short-term (48 hour, 50°C) exposures of 410SS coupons in bio-oils with addition of small carboxylic acids are shown in Figure 1. Mass change plot vs the concentration of formic acid is shown in the left graph. We observed linear increase in mass loss of 410SS with increasing formic acid concentration in the bio-oil. This is expected given our previous results that showed corrosivity of formic acid towards low chromium alloys. Iron formate was the main corrosion product that formed on the surface. However, acetic acid shows the opposite effect on mass change data as shown in the graph on the right in Figure 1. Increasing addition of acetic acid resulted in decreased mass loss. This result is intriguing because acetic acid unexpectedly behaves as a corrosion inhibitor. We are currently performing more experiments to study this effect and to understand the reason for seemingly inhibitory effect of acetic acid on corrosion of 410 stainless steel. Mass changes and cross-sectional examination of post-exposure SS410 specimens, using scanning electron microscopy equipped with energy dispersive x-ray spectroscopy, will also be presented. Impedance data from EIS measurements were analyzed as another means to assess corrosion performance of SS410 in the bio-oil and used for comprehensive corrosion assessment along with other results. Funding provided by DOE Bioenergy Technologies Office. Figure 1

Mapping the path forward to next generation algal technologies: Workshop on understanding the rules of life and complexity in algal systems

Algal technology offers enormous potential as a source of renewable biomass and bioproducts for fuels, biochemicals, nutrients, and numerous other applications. While tremendous opportunities exist, significant challenges are also present in harnessing and utilizing this valuable and potentially sustainable bioproduction platform. Funded by a joint partnership between the Bioenergy Technologies Office (BETO) at the Department of Energy (DOE) and the National Science Foundation (NSF), the recent virtual workshop, “Understanding the Rules of Life: Complexity in Algal Systems Workshop,” was organized to bring together thought leaders from academia, national laboratories and other government agencies, and industry to identify key challenges and propose research strategies to overcome these barriers. Two parallel sessions were undertaken: 1) algae strain and toolkit development and 2) algal ecosystem and microbiome dynamics, in order to advance algae engineering and cultivation efforts. In each session, attendees discussed the most pressing challenges from the perspective of model systems and omics analysis. Themes such as genetic engineering toolboxes, translation from the laboratory to outdoor cultivation, functional genomics, metabolomics, algal ecology, consortial design, microbiome dynamics, mathematical models, and data analytics emerged from the discussion. Overall, this workshop has served to elucidate the key hurdles and many opportunities present as we continue to advance algal science and technology from the laboratory and into the commercial realm.

(Invited) Increasing Biogas to Liquid Fuel Yield By Solid Oxide Co-Electrolysis of Biogas CO2 Fraction

OxEon Energy, LLC (OxEon) plans to demonstrate production of liquid hydrocarbon fuels using both the methane and CO2 generated in a food waste digester operated by the Environmental Products & Technologies Corporation (EPT). The EPT food waste digester in Burley Idaho sells produced biogas into a natural gas pipeline after separating and venting the bio-CO2. This project will convert the bio-methane to synthesis gas (syngas, as CO & H2) using a non-thermal plasma catalyzed autothermal reformer. To achieve high bio-carbon utilization, an OxEon high temperature solid oxide co-electrolysis (HTCE) system will electrochemically generate additional syngas from the bio-CO2 combined with steam raised by cooling the Fischer Tropsch (FT) reactor. Syngas from the reformed methane and co-electrolyzed CO2, will be converted to liquid fuels using an OxEon developed FT reactor. Each of the technology components have been field tested independently and will be combined for the first time in this project. The project outcome will be an engineering scale demonstration of liquid hydrocarbon bio-fuel production achieving > 50% conversion to liquids of the biogenic carbon in both CH4 & CO2 produced by an anaerobic digester.Each of the three technology elements of the integrated engineering test incorporates numerous innovations. The plasma reactor is designed to be fuel flexible, sulfur tolerant, and economically scalable to small, distributed bio-gas resources. It is also very efficient using a low power non- thermal plasma. High temperature solid oxide electrolysis has demonstrated efficiency at the thermodynamic limit as shown by analysis and testing at DOE and NASA laboratories, and is unique in its ability to co-electrolyze steam and CO2 directly to syngas. The HTCE stacks use innovations proven for the NASA Mars 2020 project which required exceptional ruggedness and effective high temperature seals. The FT reactor enables economical fabrication of smaller size synthetic fuel plants designed to match the scale of distributed renewable biomass resources. This is achieved with large diameter standard piping combined with a novel internal thermal management structure.The status of the technology elements and the planned engineering demonstration will be presented.This work is supported by the Bioenergy Technologies Office of the US Department of Energy.

(Invited) Production of Liquid Hydrocarbons from Anaerobic Digester Gas

OxEon Energy, LLC (OxEon) plans to demonstrate production liquid hydrocarbon fuels using both the methane and CO2 generated in the food waste digester operated by the Environmental Products & Technologies Corporation (EPT). The EPT food waste digester in Burley Idaho sells produced biogas into a natural gas pipeline after separating and venting the bio-CO2. This project will convert the bio-methane to synthesis gas (syngas, as CO & H2) using a non-thermal plasma catalyzed autothermal reformer. To achieve high bio-carbon utilization, high temperature solid oxide co-electrolysis (HTCE) system will electrochemically generate additional syngas from the bio-CO2 combined with steam raised by cooling the Fischer Tropsch (FT) reactor. Syngas from the reformed methane and co-electrolyzed CO2, will be converted to liquid fuels using the FT reactor. Each of the technology components have been field tested independently and will be combined for the first time in this project. The project outcome will be an engineering scale demonstration of liquid hydrocarbon bio-fuel production achieving > 50% conversion to liquids of the biogenic carbon in both CH4 & CO2 produced by an anaerobic digester.Each of the three technology elements of the integrated engineering test incorporates numerous innovations. The plasma reactor is designed to be fuel flexible, sulfur tolerant, and economically scalable to small, distributed bio-gas resources. It is also very efficient using a low power non- thermal plasma. High temperature electrolysis has demonstrated efficiency at the thermodynamic limit as shown by analysis and testing at DOE and NASA laboratories, and is unique in its ability to co-electrolyze steam and CO2 directly to syngas. The HTCE stacks use innovations proven for the NASA Mars 2020 project which required exceptional ruggedness and effective high temperature seals. The FT reactor enables economical fabrication of smaller size synthetic fuel plants designed to match the scale of distributed renewable biomass resources. This is achieved with large diameter standard piping combined with a novel internal thermal management structure.The status of the technology elements and the planned engineering demonstration will be presented.This work is supported by the Bioenergy Technologies Office of the US Department of Energy.

Impact of hydrolysis on surface area and energy storage applications of activated carbons produced from corn fiber and soy hulls

Complete utilization of lignocellulosic biomass through the creation of value-added coproducts is one of the key strategies of the Bioenergy Technologies Office (BETO) for the cost-effective production of biofuels and biochemicals. A green approach to producing lightweight and high specific surface area (SSA) activated carbons (ACs) from sustainable biomass sources is of great interest to producers and users of energy devices such as batteries and supercapacitors. While direct conversion from biomass has been studied extensively, AC with relatively high surface areas can be produced more cost-effectively when leveraged as a co-product from a biorefinery. In this paper, we discuss the production of high specific surface area activated carbons from residual fiber (fiber remaining after extraction of C5-sugars) generated as part of a C5 biorefinery. The surface, morphological characteristics using SEM and TEM, and energy storage behavior of ACs produced using the C5 extracted residual fiber were evaluated in the present study. The ACs produced from the residual fiber delivered an order of magnitude higher surface area than the one directly from corn pericarp fiber and soy hulls. The surface area of the ACs produced from pre-hydrolysis DDG was only 10 m2/g compared to 689 m2/g for soy hulls whereas after hydrolysis these values increased significantly (DDG: 1700 m2/g and soy hulls: 1300 m2/g). TEM images indicated high exfoliation, explaining the change in surface area values. Under the same current density (500 mA/g) the cycling performance of the ACs increased as the surface area increased significantly.

Lessons from a large‐scale systems dynamics modeling project: the example of the biomass scenario model

AbstractThe biomass scenario model (BSM) is a dynamic model of the biomass‐to‐biofuels supply chain in the U.S.A., developed during a multi‐year analysis effort conducted by the National Renewable Energy Laboratory (NREL), under sponsorship from the United States Department of Energy (DOE) Bioenergy Technologies Office (BETO). The BSM project, which received the 2018 Applications Award by the International System Dynamics Society, has supported collaborative analyses, developed scenarios for industry development and facilitated stakeholder engagement. We summarize insights gained from the BSM project that may be useful to other large‐scale dynamic modeling efforts. We summarize the project focus, the analysis process, key outcomes and observations on successful execution of such a product. Key points include the value of a multidisciplinary team with clear roles, engagement of experts and stakeholders, and use and reuse of simple, modular structures. The overall effort suggests that these practices may aid long‐term, team‐focused, multi‐stakeholder modeling efforts.© 2019 System Dynamics Society

Estimation of the Maximum Theoretical Productivity of Fed-Batch Bioreactors * *This work was funded by the US Department of Energy’s Bioen-ergy Technologies Office (DOE-BETO), Contract No. DE-AC36-08GO28308 with the National Renewable Energy Laboratory

Abstract A key step towards the development of an integrated biorefinery is the screening of economically viable processes, which depends sharply on the yields and productivities that can be achieved by an engineered microorganism. In this study, we extend an earlier method which used dynamic optimization to find the maximum theoretical productivity of batch cultures to explicitly include fed-batch bioreactors. In addition to optimizing the intracellular distribution of metabolites between cell growth and product formation, we calculate the optimal control trajectory of feed rate versus time. We further analyze how sensitive the productivity is to substrate uptake and growth parameters.

DOE funds cleantech, but will it last?

In the waning days of 2016, the bioenergy technologies office of the U.S. Department of Energy announced six awards totaling just under $13 million to companies planning pilot- and demonstration-scale biorefinery projects. DOE said it anticipates awarding an additional phase of funding in 2018 to help firms construct and operate the facilities. However, President-elect Trump has stated that he does not support subsidies for new energy projects. In a 2012 Twitter comment, he criticized a DOE loan that was given to the solar firm Solyndra, which went bankrupt. Under the current DOE program, LanzaTech will receive $4 million to expand the use of a demonstration facility in Soperton, Ga., that makes jet fuel and diesel from ethanol. The company uses microbes to make ethanol from industrial waste gases and converts it to fuel using a process it developed with Pacific Northwest National Laboratory. The new funds will allow LanzaTech to

The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production.

Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office’s (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes.

Getting to low-cost algal biofuels: A monograph on conventional and cutting-edge harvesting and extraction technologies

Among the most formidable challenges to algal biofuels is the ability to harvest algae and extract intracellular lipids at low cost and with a positive energy balance. In this monograph, we construct two paradigms that contrast energy requirements and costs of conventional and cutting-edge Harvesting and Extraction (H&E) technologies. By application of the parity criterion and the moderate condition reference state, an energy–cost paradigm is created that allows 1st stage harvesting technologies to be compared with easy reference to the National Alliance for Advanced Biofuels and Bioproducts (NAABB) target of $0.013/gallon of gasoline equivalent (GGE) and to the U.S. DOE's Bioenergy Technologies Office 2022 cost metrics. Drawing from the moderate condition reference state, a concentration-dependency paradigm is developed for extraction technologies, making easier comparison to the National Algal Biofuels Technology Roadmap (NABTR) target of less than 10% total energy. This monograph identifies cost-bearing factors for a variety of H&E technologies, describes a design basis for ultrasonic harvesters, and provides a framework to measure future technological advancements toward reducing H&E costs. Lastly, we show that ultrasonic harvesters and extractors are uniquely capable of meeting both NAABB and NABTR targets. Ultrasonic technologies require further development and scale-up before they can achieve low-cost performance at industrially relevant scales. However, the advancement of this technology would greatly reduce H&E costs and accelerate the commercial viability of algae-based biofuels.

Summary Report on the 2012 Sun Grant National Conference: Science for Biomass Feedstock Production and Utilization

Abstract The 2012 Sun Grant National Conference on Science for Biomass Feedstock Production and Utilization was held on 2–5 October 2012, in New Orleans, LA, USA. The Sun Grant Initiative set out to highlight recent advances in science and technology contributing to the deployment of conventional and advanced biofuels and bioproducts from agricultural and forest systems. The Initiative, with sponsorship from the Department of Energy’s Bioenergy Technologies Office (BETO), assembled an agenda focusing on promoting collaboration between academic, industry, non-profit, and government partners. This special issue is comprised of a small sample of conference presentations selected to reflect important research progress and to highlight the range of issues that must be considered as the transition to biomass energy takes hold.

Erratum to: Crop Residue Considerations for Sustainable Bioenergy Feedstock Supplies

Two regrettable errors occurred in citing a critical funding source for the multi-location research summarized in the 2014 article entitled “Crop Residue Considerations for Sustainable Bioenergy Feedstock Supplies” by Douglas L. Karlen and Jane M. F. Johnson (BioEnergy Research 7:465–467 DOI 10.1007/ s12155-014-9407-y). Within the abstract, the sentence stating that: “This overview highlights ... as part of the National Institute for Food and Agriculture Sun Grant Regional Feedstock Partnership Corn Stover Team” should read “This overview highlights ... as part of the Department of Energy Bioenergy Technologies Office’s Regional Feedstock Partnership Corn Stover Team (as part of the Sun Grant Initiative). Also, in the second paragraph of the article, the sentence stating that: “The SOC and GHG concerns ... Therefore, working through the Office of Biomass Products” (now known as the Biomass Energy Technology Office the DOE... through the NIFA Sun Grant Association to address those needs” should read “The SOC and GHG concerns ... through the DOE Bioenergy Technologies Office, the DOE ... through the Sun Grant Initiative to address those needs.” We deeply regret these errors and want the readers of BioEnergy Research to know that the USDA-ARS Resilient EconomicAgricultural Practices (formerly theRenewable Energy Assessment Project) REAP team is very grateful for the collaborative research that was enhanced by these DOE fiscal resources.