SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Here, we demonstrate that ultrafast laser filaments can excite chlorophyll fluorescence in green algae and show that it is a promising technique for remote detection of uranium exposure from the shape of the fluorescence time profile.
Hydrogen gas functions as a key component in the metabolism of a wide variety of microorganisms, often acting as either a fermentative end-product or an energy source. The number of organisms reported to utilize hydrogen continues to grow, contributing to and expanding our knowledge of biological hydrogen processes. Here we demonstrate that Volvox carteri f. nagariensis, a multicellular green alga with differentiated cells, evolves H 2 both when supplied with an abiotic electron donor and under physiological conditions. The genome of Volvox carteri contains two genes encoding putative [FeFe]-hydrogenases (HYDA1 and HYDA2), and the transcripts for these genes accumulate under anaerobic conditions. The HYDA1 and HYDA2 gene products were cloned, expressed, and purified, and both are functional [FeFe]-hydrogenases. Additionally, within the genome the HYDA1 and HYDA2 genes cluster with two putative genes which encode hydrogenase maturation proteins. This gene cluster resembles operon-like structures found within bacterial genomes and may provide further insight into evolutionary relationships between bacterial and algal [FeFe]-hydrogenase genes.
This report relays the important role biofuels such as algae could have in the energy market. The report cites the problem of crude oil becoming less abundant while the demand for energy continues to rise. There are many benefits of producing energy with biofuels such as fewer carbon emissions as well as less land area to produce the same amount of energy compared to other sources of renewable fuels. One challenge that faces biofuels right now is the cost to produce it is high.
The Department of Energy’s Bioenergy Technology Office (BETO) collaborates with a wide range of institutions towards the development and deployment of biofuels and bioproducts. To facilitate this effort, BETO and its partner national laboratories develop detailed techno-economic assessments (TEA) of biofuel production technologies as part of the development of design cases and state of technology (SOT) analyses. A design case is a TEA that outlines a target case for a particular biofuel pathway. It enables preliminary identification of data gaps and research and development needs and provides goals and targets against which technology progress is assessed. On the other hand, an SOT analysis assesses progress within and across relevant technology areas based on actual experimental results relative to technical targets and cost goals from design cases and includes technical, economic, and environmental criteria as available. BETO also develops supply chain sustainability analyses (SCSA) for key biofuel production technologies that are the subject of design case or SOT analyses (Dunn et al. 2013). The SCSA utilizes a life-cycle analysis to estimate the energy use and greenhouse gas (GHG) emissions associated with biofuel production and assists in comparing several biofuel pathways. This report documents an SCSA of whole algae hydrothermal liquefaction (AHTL) as the conversion technology to produce renewable diesel (RD). Jones et al. (2014) developed the design case process model that provides the material and energy intensity of the feedstock conversion step in the SCSA. In this study, conversion of algal biomass to RD is achieved by whole AHTL, as described in the design report by Pacific Northwest National Laboratory (Jones et al., 2014). Wet algal biomass, as undisrupted cells, is converted into a liquid fuel with pressurized water in a condensed phase. The SCSA for this pathway is described.
The potential for producing biofuels from algae has generated much excitement based on projections of large oil yields with relatively little land use. However, numerous technical challenges remain for achieving market parity with conventional non-renewable liquid fuel sources. Among these challenges, the energy intensive requirements of traditional cell rupture, lipid extraction, and residuals fractioning of microalgae biomass have posed significant challenges to the nascent field of algal biotechnology. Our novel approach to address these problems was to employ low cost solution-state methods and biochemical engineering to eliminate the need for extensive hardware and energy intensive methods for cell rupture, carbohydrate and protein solubilization and hydrolysis, and fuel product recovery using consolidated bioprocessing strategies. The outcome of the biochemical deconstruction and conversion process consists of an emulsion of algal lipids and mixed alcohol products from carbohydrate and protein fermentation for co-extraction or in situ transesterification.
To present a more unified picture of the long-term future potential for algal biofuels and the goals that must be met to reach that potential, four algae modeling groups collaborated to harmonize respective models for resource assessment (Pacific Northwest National Laboratory), techno-economic analysis (National Renewable Energy Laboratory and Pacific Northwest National Laboratory), and life-cycle analysis (Argonne National Laboratory) of algal biomass production and conversion processes. In contrast to prior harmonization studies that this group has previously conducted, which focused on establishing benchmarks attributed to current performance at the time, the primary intent of the present harmonization study was to project these models to forward-looking targets that must be achieved to reduce fuel costs and greenhouse gas emission profiles to Bioenergy Technologies Office target levels, subject to specific location constraints imposed by resource assessment modeling and thus national-scale fuel output potential (i.e., billion gallons gasoline equivalent per year, or BGGE/yr). In all, while based on a number of aspirational goals not yet demonstrated but plausible to achieve over coming years, the harmonized outputs indicate promising potential for algal biofuels to make a significant contribution to the U.S. fuels market, based on substantial quantities of biomass (104-235 MM tons/yr) projected to be available at costs below 700/ton (generally below 500/ton for freshwater cultivation). While these costs are still significantly higher than terrestrial biomass cost targets, the propensity for capturing high fuel yields and/or high-value tailored coproducts from algal biomass is shown here to provide plausible paths to achieve future targets for cost and sustainability metrics at meaningful volumes.
Presentation for the University of New Mexico on a group lesson to replicate cultures of algae species.
The UNCLE-SAM project, under the Biotechnologies to Ensure a Robust Supply of Critical Materials for Clean Energy program, examined the biomining applications of seaweeds for sustainable, domestic production of critical mineral feedstocks. The ocean is a vast reserve of mineralogical wealth including rare earth elements (REEs) and platinum group metal (PGMs). These elements, categorized as “critical minerals”, are used in telecommunication devices, lasers, LED lighting, turbine generators, electric car motors, jet engine alloys, and many other applications. These critical elements are increasingly vital to a thriving, efficient and sustainable society. However, only a few countries in the global market currently produce and export REEs, leading to potential geopolitical supply disruptions. Marine macroalgae, often referred to as seaweeds, bioconcentrate critical minerals from seawater, including REEs and PGMs. Marine algae cultivation can generate a significant amount of biomass with minimal freshwater, fertilizer, and land requirements. In summary, the UNCLE-SAM project successfully evaluated the technological feasibility for marine macroalgal cultivation as a feedstock for critical minerals, explored the biological capacity of different seaweeds to provide economically relevant domestic mineral production, assessed processing techniques for thermal co-conversion of seaweeds into renewable fuel and mineral feedstocks, and executed techno-economic and lifecycle assessments for identifying the most critical gaps in our current understanding to move the technology into commercially relevant deployment. Further development of this technology could transform the bioproduct and REE mining industries and catalyze the development of a more sustainable future.
The UNCLE-SAM project, under the Biotechnologies to Ensure a Robust Supply of Critical Materials for Clean Energy program, examined the biomining applications of seaweeds for sustainable, domestic production of critical mineral feedstocks. The ocean is a vast reserve of mineralogical wealth including rare earth elements (REEs) and platinum group metal (PGMs). These elements, categorized as “critical minerals”, are used in telecommunication devices, lasers, LED lighting, turbine generators, electric car motors, jet engine alloys, and many other applications. These critical elements are increasingly vital to a thriving, efficient and sustainable society. However, only a few countries in the global market currently produce and export REEs, leading to potential geopolitical supply disruptions. Marine macroalgae, often referred to as seaweeds, bioconcentrate critical minerals from seawater, including REEs and PGMs. Marine algae cultivation can generate a significant amount of biomass with minimal freshwater, fertilizer, and land requirements. In summary, the UNCLE-SAM project successfully evaluated the technological feasibility for marine macroalgal cultivation as a feedstock for critical minerals, explored the biological capacity of different seaweeds to provide economically relevant domestic mineral production, assessed processing techniques for thermal co-conversion of seaweeds into renewable fuel and mineral feedstocks, and executed techno-economic and lifecycle assessments for identifying the most critical gaps in our current understanding to move the technology into commercially relevant deployment. Further development of this technology could transform the bioproduct and REE mining industries and catalyze the development of a more sustainable future.
This report describes the overall findings of the research project “Integrating an Industrial Source and Commercial Algae Farm with Innovative CO 2 Transfer Membrane and Improved Strain Technologies”. The motivation and goal for this project were to increase the carbon utilization efficiency (CUE) and areal productivity for algal cultivations, thereby reducing CO 2 costs to cultivation operations and improving economics. This was achieved through a combination of enhanced delivery of inorganic carbon and improved strains of Nannochloropsis oceanica capable of higher rates of bicarbonate uptake and metabolism. The project succeeded in these goals. First, a bubble-free, membrane-based technology was developed for delivering CO 2 to cultivations, which increased the CUE from the 15-20% that is standard in the industry to more than 65%. In addition, N. oceanica was modified to express a bicarbonate transporter protein, BicA, which enabled the cells to grow more quickly. In addition, advances were made in the protein engineering of carbonic anhydrase (CA) for enhanced stability and catalytic performance, the computational fluid dynamics modeling of algal cultivation systems, and in the life-cycle assessment and technoeconomic analysis of algal production. Together, these outcomes contribute to advancing algal cultivation as an economically viable platform for production of fuels, materials, and other chemical products. The project results aid in addressing the dual challenges of reducing atmospheric CO 2 levels and achieving green energy solutions.
Efficient DNA extraction is essential for accurately monitoring microalgae communities in large-scale cultivation systems such as raceway ponds and wastewater ponds. Traditional phenol chloroform extracts are a staple in microbiology but are obsolete for routine sampling due to its high toxicity reagents and time intensive setups. Commercial DNA extraction kits are more favorable for the microbes found in these ponds, but lack specific kits made for these communities. Little is known about which kits perform the best, leading researchers to use a variety of different kits with inconsistent results. This project compared one precipitation based commercial kit (Lucigen Masterpure) and five wash based kits (Monarch, Zymo Quick-DNA, and three Qiagen DNeasy kits) using four brackish algae strains to determine which methods yield the greatest quantity and quality of genomic DNA. Extractions were evaluated using the manufacturers protocol, and additional pretreatment options were administered before a single kit to compare its potential in being added routinely before extractions. Pretreatment options included both cryogenic freeze-thawing and heat incubation using enzymes. DNA was quantified using Qubit fluorometry and NanoDrop purity ratios. Overall, the Qiagen PowerWater kit provided the highest DNA yield and purity, but at a significantly higher cost then the precipitation-based kit (MasterPure). It was also noted that while the precipitation-based kit was significantly cheaper, provided similar results, it took significantly more time to complete a single run. Cryogenic pretreatment (6x cycles) increased average DNA yields by up to 80%, whereas enzymatic pretreatment most improved purity ratios without substantially improving quantity. The results suggest that it may be more cost and time efficient to use Qiagen kits with the addition of lysis pretreatments to procure better results. Future works includes developing a better system to efficiently collect multi variable data, and to upscale to artificial polycultures using similar methodologies alongside sequencing to confirm kit results.
This project focused on developing advanced optical coatings to improve solar energy utilization. The research aimed to create lanthanide-doped upconversion nanoparticles (UCNPs) capable of capturing unused near-infrared (NIR) light from the sun and converting it into visible light (blue and red photons) that can be used for photosynthesis. The primary goal was to identify, synthesize, and integrate highly efficient UCNPs into a transparent thin-film device. Through a comprehensive workflow involving computer simulations, high-throughput robotic synthesis, and detailed optical characterization, the project successfully developed a high-performance material. The key technical achievement was the creation of a core-shell UCNP (NaYF₄:20%Yb³⁺, 2%Er³⁺ coated with a 10 nm NaYF₄ shell) that demonstrated a quantum yield of 3.2% for converting 980 nm NIR light into visible light. Transparent thin films fabricated from these nanoparticles showed excellent optical properties, confirming their potential for practical applications. This research adds to the scientific understanding of energy transfer in lanthanide materials and demonstrates a technically effective method for creating efficient light-converting coatings. The primary benefit to the public lies in the potential for these coatings to enhance the efficiency of solar-driven processes, such as boosting the growth of algae in photobioreactors for biofuel production.
This project combined experimental algal cultures with predictive quantum calculations to evaluate system-level CO 2 uptake and conversion efficiency of cellulose-producing Nannochloropsis sp. algae. Recently, Nannochloropsis sp. has garnered attention as a novel host organism for converting low-cost CO 2 produced from cellulosic ethanol fermentations into algal lipids for biodiesel production and microcrystalline cellulose as a high-value co-product. As depicted in the figure below, this project (1) optimized Nannochloropsis salina (N. salina) cultures on effluent gas produced directly from cellulosic ethanol fermentation, (2) characterized the fermentation products, quantify cellulose production, and calculate CO 2 uptake efficiency with predictive quantum calculations, (3) conducted a life cycle and techno economic analysis of the proposed integration, and (4) provided training opportunities to students attending UC Riverside.
This project cultivated microalgae biomass as attached growth on a 3,000 gallon pilot Rotating Algae Biofilm Reactor to remediate municipal wastewater by removing nutrients nitrogen and phosphorus and also produce value bioproducts including compostable bioplastic.
This document is a close-out report for two Pacific Northwest National Laboratory (PNNL) projects funded by the Alternative Fuels and Feedstocks Office (formerly the Bioenergy Technologies Office) of the Department of Energy (DOE). The two projects are: • Thermochemical Interface (DOE ref. no. 1.3.4.101, PNNL ref. no. 64490) • HTL Model Development (DOE ref. no. 1.3.5.202, PNNL ref. no. 71612) At the end of fiscal year 2025, both projects ended. Additional activities related to the topics of algae, hydrothermal liquefaction (HTL), and the techno-economic assessment of HTL of algal feedstocks will be studied in other projects. Key technical findings of the projects were published in early 2025 and highlights will be summarized in this document. A summary of recent technical findings from 2025 are also included herein. This close-out report summarizes key outcomes from both projects highlighting the value and technical impact achieved.
The purpose of this project was to advance and scale the algae-based technology Helios-NRG has been developing for capture of CO 2 from the flue gas of coal-burning power plants with conversion of the CO 2 to high-value products. In order to encourage the process becoming commercial and be adoptable, it is essential that the cost of CO 2 be close to net zero or slightly revenue positive. Two methods to achieve this are reducing the cost of operations through efficiencies and selling of products derived from conversion. Helios and the project team partners have accomplished the goals of furthering the technology to be more scalable and substantially lower cost with a defined pathway for commercialization.
Dunaliella salina and Dunaliella tertiolecta are extremophile, marine algae that can survive in very low Fe conditions. In this study, we used TMT-proteomics to compare the Fe starvation responses to the Fe replete responses. Samples were digested with trypsin, labeled with TMT 10-Plex, then analyzed by LC-MS/MS. Data was searched with MS-GF+ using PNNL's DMS Processing pipeline.
A draft metagenome-assembled genome (MAG) of a Salinarimonas species was obtained from a sequenced metagenome of Chlorella sp. SLA-04, an alkaliphilic green alga.