Advanced Conversion Technologies Research Articles

High capacity CO₂ capture by α-BeH₂ nanosheet through charge modulation: A first-principles study

The increasing concern regarding elevated atmospheric CO₂ levels and their environmental impact is driving the development of advanced materials and technologies for efficient CO₂ capture and conversion. In this study, we focus on investigating the adsorption of CO₂ on beryllium hydride (α-BeH₂) nanosheets through charge modulation, using density functional theory calculations. There is minimal difference in adsorption energy between the 1e⁻ negatively charged surface and the neutral surface. Our findings indicate that the adsorption energy of CO₂ can be significantly enhanced by introducing three positively charged states. These results demonstrate that the +3e positively charged α-BeH₂ surface is an excellent sorbent for CO₂ capture, with an adsorption energy of −0.85 eV/CO₂. This indicates a transition from physisorption to chemisorption on these positively charged nanosheets. Focusing on the adsorption behavior, we discovered that introducing three positive charges into the α-BeH₂ nanosheet enables the uptake of eighteen CO₂ molecules. This achieves a CO₂ capture capacity of 74.18 wt% and an adsorption energy of −0.51eV/CO₂. These values are significantly higher than those observed with many other 2D substrates. Molecular dynamics (MD) simulations confirmed the thermal stability of the 18CO₂/BeH₂ complex at 300 K. Overall, our findings highlight α-BeH₂ monolayers with 3e positive charges as a promising substrate for highly efficient CO₂ capture.

Biomass and organic waste conversion for sustainable bioenergy: A comprehensive bibliometric analysis of current research trends and future directions

The rising demand for renewable energy sources has fueled interest in converting biomass and organic waste into sustainable bioenergy. This study employs a bibliometric analysis (2013-2023) of publications to assess trends, advancements, and future prospects in this field. The analysis explores seven key research indicators, including publication trends, leading contributors, keyword analysis, and highly cited papers. We begin with a comprehensive overview of biomass as a renewable energy source and various waste-to-energy technologies. Employing Scopus and Web of Science databases alongside Biblioshiny and VOSviewer for analysis, the study investigates publication patterns, citation networks, and keyword usage. This systematic approach unveils significant trends in research focus and identifies prominent research actors (countries and institutions). Our findings reveal a significant increase in yearly publications, reflecting the growing global focus on biomass and organic waste conversion. Leading contributors include China, the United States, India, and Germany. Analysis of keywords identifies commonly used terms like "biofuels," "pyrolysis," and "lignocellulosic biomass." The study concludes by proposing future research directions, emphasizing advanced conversion technologies, integration of renewable energy sources, and innovative modelling techniques.

Biofuels Production: A Review on Sustainable Alternatives to Traditional Fuels and Energy Sources

With increased worldwide energy demand and carbon dioxide emissions from the use of fossil fuels, severe problems are being experienced in modern times. Energy is one of the most important resources for humankind, and its needs have been drastically increasing due to energy consumption, the rapid depletion of fossil fuels, and environmental crises. Therefore, it is important to identify and search for an alternative to fossil fuels that provides energy in a reliable, constant, and sustainable way that could use available energy sources efficiently for alternative renewable sources of fuel that are clean, non-toxic, and eco-friendly. In this way, there is a dire need to develop technologies for biofuel production with a focus on economic feasibility, sustainability, and renewability. Several technologies, such as biological and thermochemical approaches, are derived from abundant renewable biological sources, such as biomass and agricultural waste, using advanced conversion technologies for biofuel production. Biofuels are non-toxic, biodegradable, and recognized as an important sustainable greener energy source to conventional fossil fuels with lower carbon emissions, combat air pollution, empower rural communities, and increase economic growth and energy supply. The purpose of this review is to explain the basic aspects of biofuels and their sustainability criteria, with a particular focus on conversion technologies for biofuel production, challenges, and future perspectives.

The pathway for achieving sustainable aviation fuel production in the Middle East and North Africa region

AbstractThe Middle East and North Africa (MENA) region faces significant challenges in the production of sustainable aviation fuel (SAF) due to high costs, limited feedstock availability, and underdeveloped infrastructure. However, the region has diverse feedstock options and can leverage existing refining capabilities and advanced conversion technologies for SAF production. Addressing these challenges requires research and development (R&D) collaboration, supportive policies, and international knowledge exchange. To promote the production of SAF in the MENA region, a comprehensive strategy is required that includes collaboration, policy alignment, research and development, infrastructure development, and training. Market incentives such as regulations and financial support can help drive demand for SAF. Collaborating with international organizations can improve knowledge sharing and promote sustainable practices. Research and development collaboration is crucial for innovation and establishing a strong SAF industry. Policy harmonization can create a supportive framework for investment and innovation. Monitoring and reporting mechanisms can ensure transparency and verify sustainability. By addressing these aspects, the region can become a leading hub for SAF production and contribute to a sustainable aviation industry.

LIGNOCELLULOSE BIOMASS DELIGNIFICATION USING ACID HYDROTROPE AS GREEN SOLVENT: A MINI-REVIEW

"Efficient and cost-effective conversion of lignocellulosic biomass into usable forms of energy presents unique challenges. Lignocellulosic biomass, comprising cellulose, hemicelluloses, and lignin, necessitates advanced conversion technologies. Common commercial delignification techniques, including kraft pulping, sulfite pulping, acid hydrolysis, and organosolv pulping, often involve harsh conditions leading to structural changes in lignin and environmental impacts. To address these issues, acid hydrotropes have emerged as a promising method for lignin extraction. Acid hydrotropes, represented by p-toluenesulfonic acid (p-TsOH), enable the solubilization of hydrophobic substances like lignin. This mini-review provides an overview of various lignocellulose fractionation techniques and explores the acid hydrotrope approach. The mechanism behind acid hydrotropic fractionation is discussed, and its performance is evaluated. In conclusion, the review emphasizes the pivotal role of the acid hydrotrope approach in advancing lignocellulosic biomass conversion technology, promoting a sustainable and efficient bio-based economy."

Adoption of biofuels for marine shipping decarbonization: A long‐term price and scalability assessment

AbstractThis study assessed the long‐term annual biofuel production capacity potential and price in the United States and shed light on the prospect of biofuel adoption for marine propulsion. A linear programming model was developed to assist the projections and provide insightful analyses. The projected long‐term (2040) maximum annual capacity of biofuels in the United States is 245 million metric tons (Mt) or 65 billion gallons of heavy fuel oil gallon equivalent (HFOGE) when based on the median feedstock availability. Between 2022 (near‐term) and 2040, the potential biofuel capacity increases by over 40%, attributed to increased feedstock availability. At a price range up to $500/t, biodiesel is the main product, and the annual capacity (12 Mt) is limited to feedstock availability constraints. Biodiesel and corn ethanol are the main biofuels at a price range up to $750/t. At a higher price point (above $750/t), the biofuel types and annual capacities increase substantially (218 Mt per year). Biofuels above this price include gasoline‐, jet‐, and diesel‐range blendstocks, as well as bio‐methanol, bio‐propane, and biogas. This study concludes that the US domestic feedstock availability coupled with advanced conversion technologies can produce substantial amounts of biofuels to achieve a critical mass and be impactful as alternative marine fuels. There is also a need to improve the biofuel price for marine shipping adoption. Policies and economic incentives that provide temporary financial support would help facilitate maritime biofuel adoption. © 2022 Alliance for Sustainable Energy, LLC. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Cryogenic Carbon Capture™ (CCC) Status Report

This material is based upon work supported by the Advanced Research Projects Agency – Energy (ARPA-E), U.S. Department of Energy under Award Number DE-A101 and by the National Energy Technology Laboratory (NETL), U.S. Department of Energy under Award Number DE-F847. Additional support was provided by the Advanced Conversion Technologies Task Force in Wyoming, the Climate Change and Emissions Management Corporation (CCEMC) in Alberta, Canada, Rocky Mountain Power (PacifiCorp), and the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia.

Experimental investigation of the temperature distribution in a microwave-induced plasma reactor

It is urgent to reduce CO2 emissions to mitigate the impacts of climate change. The development of advanced conversion technologies integrated with plasma torches provides a path for the optimisation of clean energy recovery from biomass and wastes, thus substituting fossil fuels utilization. This article presents the temperature characterisation within a laboratory-scale microwave-induced plasma reactor operated with air, H2O and CO2 as the plasma working gases. The benefits associated with the plasma torch are highlighted and include rapid responses of the plasma and the temperature profile within the reactor to changing operating conditions. The average temperature near the side wall in the laboratory-scale reactor is proportional to the applied microwave power, ranging from 550 °C at 2 kW to 850 °C at 5 kW, while significantly higher temperatures are locally present within the plasma plume. The described system demonstrates promising conditions that are ideal for effective energy recovery from biomass and wastes into clean fuel gas.

Pyrolysis kinetics of short rotation coppice poplar biomass

Abstract Woody biomass can be converted into green fuels by advanced conversion technologies such as gasification and pyrolysis. Due to the complexity of woody biomass, the thermochemical decomposition mechanisms are complex and the knowledge of pyrolysis kinetics is mandatory for optimization of the process and reactor design of commercial scale biorefineries. Pyrolysis kinetics of short rotation coppice (SRC) poplar biomass (nine different clones) was studied using non-isothermal thermogravimetry. By using differential thermogravimetry data, obtained for heating rates of 10–50 K/min, the Kissinger model-free methodology showed activation energies in the range 108–320 kJ/mol, similar to those reported in the literature for cellulose pyrolysis. Isoconversional approaches of Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) obtained similar values of activation energy (81–301 kJ/mol and 90–306 kJ/mol, respectively. The kinetics parameters obtained by the FWO and KAS methods were higher than data reported in the literature for other biomasses, and a correlation between activation energy and the lignin content of the biomass samples was found. The pyrolysis activation energy seems to have no significant effect on the pyrolysis product yields, probably because, under the tested conditions (fixed bed reactor, 773 K), pyrolysis was controlled by mass and/or heat transfer limitations instead of kinetics control.

Oxygen evolution electrocatalysis using mixed metal oxides under acidic conditions: Challenges and opportunities

Shaping the energy landscape through development of more efficient electrochemical energy conversion and storage devices requires significant advancements in the catalysis of key electrochemical processes involving oxygen. This is especially the case for the oxygen evolution reaction (OER), which is largely challenged by the cost-ineffectiveness of the best performing electrocatalysts (i.e., Ru, Ir), along with their limited stability under acidic conditions. This presents a roadblock in the development of robust acid-based polymer exchange membrane electrochemical systems, currently the most advanced technologies for electrochemical energy conversion. Approaches such as dilution of Ru/Ir into flexible mixed metal oxide frameworks have been used as alternative strategies in designing robust OER electrocatalysts. Herein, we discuss the state of research in this area and detail the effect of the composition and structure of mixed metal oxides on their acidic OER activity and stability. Future directions for developing mixed metal oxide electrocatalysts suitable for acidic electrochemical environments are devised.

A biomimetic nanoleaf electrocatalyst for robust oxygen evolution reaction

Oxygen evolution reaction (OER) is a key process in various advanced technologies for renewable energy conversion, such as water splitting and metal-air batteries. However, as a four-electron coupled reaction, the OER is kinetically sluggish and limited by its high overpotential and low efficiency. The design of novel nanostructured electrocatalysts is highly desirable to promote OER kinetics. Herein, a bio-inspired nanoleaf electrocatalyst has been successfully achieved for the first time by in situ growing ultrathin NiCo layered double hydroxide (LDH) nanosheets on CuO nanowires. Attributed to the mechanical support of CuO nanowire veins, the NiCo LDH lamina presents a large lateral size (more than 10 μm) and unique hierarchical structure that consisted of ultrathin nanosheets with numerous exposed edges. The CuO veins distributed across the LDH lamina can serve as the fast path for charge transfer and significantly promote the LDH conductivity. Compared to the conventional NiCo LDH nanosheets, the novel nanoleaves with enlarged electrochemical surface area, edge-rich active sites, and improved conductivity exhibit greatly enhanced OER performances with an impressive 9.3 fold enhanced activity, much lower overpotential of 262 mV at 10 mA cm−2, as well as good stability and flexibility. The biomimetic nanoleaf structures and the corresponding design strategy can be broadly applied to other functional 2D materials for advanced applications.

Use of Euphorbia sp. (Euphorbiaceae) as biofuel feedstock for semi-arid and arid lands

Plant-based biofuels are globally accepted renewable alternatives to fossil fuels. Both biodiesel and bioethanol can be derived from various plant-based feedstocks using conventional and advanced conversion technologies. However, the use of conventional first-generation plant feedstocks creates a ‘food versus fuel’ conflict through competition with agriculture for arable land and freshwater resources. In this regard, succulent, latex-yielding species of Euphorbia (Euphorbiaceae) have advantages as feedstock for liquid biofuel production. These include high levels of primary productivity, a remarkable ability to grow on marginal lands under xeric conditions, and a relatively small bioenergy freshwater footprint. In addition, yields of Euphorbia-based biofuels are relatively high, and the fuel has chemical, physical, and combustive properties that are comparable to or exceed those of fossil fuels. In this review, we summarize the status of biofuel research using Euphorbia feedstock. Harvesting and drying of biomass, extraction, characterization and refinement of biocrude, blending with diesel, fuel properties, effects on engine performance and emissions, and use of spent residues for production of bioethanol and other valuable co-products are discussed. Major challenges and future opportunities associated with Euphorbia-based biofuel development are considered.

A Review of Metal‐ and Metal‐Oxide‐Based Heterogeneous Catalysts for Electroreduction of Carbon Dioxide

AbstractCapping and, eventually, reducing the atmospheric levels of greenhouse gases such as CO2 is an urgent priority, and a focus of multidisciplinary efforts. Among other techniques, advanced technologies for CO2 capture and conversion are highly desirable to limit CO2 emissions. Electrochemical reduction of CO2, using off‐peak renewable electricity, to value‐added chemicals and fuels has attracted extensive research interest. A main effort is directed toward the development of efficient, selective, and robust electrocatalysts to promote CO2 reduction, due to its sluggish reaction kinetics. Here, recent investigations and achievements in the design of metal‐ and metal‐oxide‐based heterogeneous catalysts are reviewed in terms of catalytic activity, selectivity, stability, and mechanism. A classification of heterogeneous CO2 catalysts is presented based on the main products of electrochemical reduction of CO2, including HCOOH, CO, C2H4, CH3OH, and C3H8O. The key catalysts' properties favoring the production of specific chemical products from the CO2 reduction reaction are critically discussed. The challenges for achieving superior CO2 reduction electrocatalysts are discussed providing future research directions for their design and development.

Energy supply modelling of a low-CO2 emitting energy system: Case study of a Danish municipality

Municipal activities play an important role in national and global CO2-emission reduction efforts, with Nordic countries at the forefront thanks to their energy planning tradition and high penetration of renewable energy sources. In this work, we present a case study of the Danish municipality of Sønderborg, whose aim is to reach zero net CO2 emissions by 2029. Sønderborg has an official strategic plan towards 2029, which we compared with four alternative scenarios to investigate how the municipality could approach its target in the most energy-efficient and cost-effective way while simultaneously keeping biomass and waste consumption close to the limits of the locally available residual resources.We modelled all sectors of the energy system on the municipal scale, applying a broad range of energy conversion technologies, including advanced biomass conversion technologies and reversible electrolysis. We constructed five scenarios, each representing a different energy mix for Sønderborg’s energy system in 2029. We modelled these scenarios using the mixed-integer linear optimization tool Sifre. We compared the results for the five scenarios using four indicators: annual total system cost, total energy system efficiency, annual net system CO2 emissions and total annual biomass consumption.The results show that scenarios with a high degree of electrification perform better on the selected indicators than scenarios with a high degree of biomass utilization. Moreover, the incorporation of advanced conversion technologies such as electrolysis, fuel cells and methanol production further reduces both the total system cost and net CO2 of the highly electrified energy system. Our sensitivity analysis demonstrates that scenarios with a low biomass consumption and a high degree of electrification are less dependent on changes in energy prices.We conclude that in order to achieve their CO2 emission goals in the most energy-efficient, cost-effective and sustainable way, municipalities similar to Sønderborg should compare a wide range of energy system configurations, for example, scenarios with a high degree of electrification and a limited biomass use.

Bridging new and old energy

Bridging new and old energy

TALEN mediated targeted mutagenesis of the caffeic acid O-methyltransferase in highly polyploid sugarcane improves cell wall composition for production of bioethanol.

Sugarcane (Saccharum spp. hybrids) is a prime crop for commercial biofuel production. Advanced conversion technology utilizes both, sucrose accumulating in sugarcane stems as well as cell wall bound sugars for commercial ethanol production. Reduction of lignin content significantly improves the conversion of lignocellulosic biomass into ethanol. Conventional mutagenesis is not expected to confer reduction in lignin content in sugarcane due to its high polyploidy (x = 10–13) and functional redundancy among homo(eo)logs. Here we deploy transcription activator-like effector nuclease (TALEN) to induce mutations in a highly conserved region of the caffeic acid O-methyltransferase (COMT) of sugarcane. Capillary electrophoresis (CE) was validated by pyrosequencing as reliable and inexpensive high throughput method for identification and quantitative characterization of TALEN mediated mutations. Targeted COMT mutations were identified by CE in up to 74 % of the lines. In different events 8–99 % of the wild type COMT were converted to mutant COMT as revealed by pyrosequencing. Mutation frequencies among mutant lines were positively correlated to lignin reduction. Events with a mutation frequency of 99 % displayed a 29–32 % reduction of the lignin content compared to non-transgenic controls along with significantly reduced S subunit content and elevated hemicellulose content. CE analysis displayed similar peak patterns between primary COMT mutants and their vegetative progenies suggesting that TALEN mediated mutations were faithfully transmitted to vegetative progenies. This is the first report on genome editing in sugarcane. The findings demonstrate that targeted mutagenesis can improve cell wall characteristics for production of lignocellulosic ethanol in crops with highly complex genomes.Electronic supplementary materialThe online version of this article (doi:10.1007/s11103-016-0499-y) contains supplementary material, which is available to authorized users.

Cross-Plane Phonon Conduction in Polycrystalline Silicon Films

Silicon films of submicrometer thickness play a central role in many advanced technologies for computation and energy conversion. Numerous thermal conductivity data for silicon films are available in the literature, but they are mainly for the lateral, or in-plane, direction for both polycrystalline and single crystalline films. Here, we use time-domain thermoreflectance (TDTR), transmission electron microscopy, and semiclassical phonon transport theory to investigate thermal conduction normal to polycrystalline silicon (polysilicon) films of thickness 79, 176, and 630 nm on a diamond substrate. The data agree with theoretical predictions accounting for the coupled effects of phonon scattering on film boundaries and defects related to grain boundaries. Using the data and the phonon transport model, we extract the normal, or cross-plane thermal conductivity of the polysilicon (11.3 ± 3.5, 14.2 ± 3.5, and 25.6 ± 5.8 W m−1 K−1 for the 79, 176, and 630 nm films, respectively), as well as the thermal boundary resistance between polysilicon and diamond (6.5–8 m2 K GW−1) at room temperature. The nonuniformity in the extracted thermal conductivities is due to spatially varying distributions of imperfections in the direction normal to the film associated with nucleation and coalescence of grains and their subsequent columnar growth.

PAF-derived nitrogen-doped 3D Carbon Materials for Efficient Energy Conversion and Storage.

Owing to the shortage of the traditional fossil fuels caused by fast consumption, it is an urgent task to develop the renewable and clean energy sources. Thus, advanced technologies for both energy conversion (e.g., solar cells and fuel cells) and storage (e.g., supercapacitors and batteries) are being studied extensively. In this work, we use porous aromatic framework (PAF) as precursor to produce nitrogen-doped 3D carbon materials, i.e., N-PAF-Carbon, by exposing NH3 media. The “graphitic” and “pyridinic” N species, large surface area, and similar pore size as electrolyte ions endow the nitrogen-doped PAF-Carbon with outstanding electronic performance. Our results suggest the N-doping enhance not only the ORR electronic catalysis but also the supercapacitive performance. Actually, the N-PAF-Carbon obtains ~70 mV half-wave potential enhancement and 80% increase as to the limiting current after N doping. Moreover, the N-PAF-Carbon displays free from the CO and methanol crossover effect and better long-term durability compared with the commercial Pt/C benchmark. Moreover, N-PAF-Carbon also possesses large capacitance (385 F g−1) and excellent performance stability without any loss in capacitance after 9000 charge–discharge cycles. These results clearly suggest that PAF-derived N-doped carbon material is promising metal-free ORR catalyst for fuel cells and capacitor electrode materials.

Improving Electrosorption Performance in Membrane Assisted Capacitive Deionization Cells Using Asymmetric Electrodes Configuration

Capacitive deionization (CDI) is an emerging salt treatment technology that functions by concentrating ionized salt into porous electrodes with the aid of an applied electric field. Unlike some de-salting technologies like distillation or reverse osmosis that separate water from salt content with the aid of added heat or pressure, CDI electrostatically targets the salt content instead, and it is particularly attractive for the treatment of mid (brackish water) to low (tap water) concentration salt streams [1]. In addition, CDI offers the possibility of energy recovery in the convenient form of electricity which can be used to directly power subsequent CDI units, or other auxiliary devices. Membrane-assisted capacitive deionization (MCDI) is an improvement to conventional CDI whereby ion-exchange membranes (IEMs) are placed next to the porous carbon electrodes to increase desalination performance by mitigating losses that result from converting electronic to ionic charge at the electrode-electrolyte double layer. During MCDI operation, electrode polarization results in the attraction of counter- ions (opposite in polarity to the charged surface), while co-ions (similar in polarity to the charged surface) are repelled away from the polarized surface [2]. The membranes used for the operation hinder the repulsion of co-ions back into the bulk, leading to an increased flux of counter-ions to balance the co-ions contained in the macropore space resulting in typically higher charge efficiencies over the CDI only system. In a departure from the traditional architecture which utilizes the same electrodes to form both the anode and cathode, MCDI systems can instead be asymmetrically assembled with ion-specific electrodes to increase specific charge excesses, and whereby any such specificity can be quantified via potential of zero charge (PZC) measurements. In order to demonstrate benefits to deionization performance, we will present the electrosorption performance and charging characteristics of MCDI cells configured with pristine and nitric acid-treated Zorflex activated carbon electrodes with PZCs of -0.2 and 0.2 V vs SCE, respectively, based on differential capacitance measurements. Results from the asymmetric configuration will be compared to those from pristine anode-pristine cathode configurations to quantify the extent of variation in performance. Acknowledgements The authors are grateful to the U.S. - China Clean Energy Research Center, U.S. Department of Energy for project funding (No. DE-PI0000017), and thankful for the support of the State of Wyoming Advanced Conversion Technologies Task Force for their support.

Bi-Directional DC/DC Converter Coupled with Capacitive Deionization for Efficient Desalination

Wastewater treatment and freshwater production are integral to sustaining an increasing global population. Presently, techniques like reverse osmosis (RO), and multi- stage distillation (MSD), which are extensively used for water cleanup are cost and energy intensive due to an operational focus on removing a majority constituent water from salts. Capacitive de-ionization (CDI) is an emerging technique for water treatment whereby dissolved ionic content in the bulk solution is stored in highly porous electrodes upon the application of an electric field, i.e., removing salts from water. When the potential is released, a concentrated waste stream is produced (1, 2). A lot of research has been devoted to optimizing the electrodes, usually carbon to possess high surface area, large porosity, and high conductivity for use in CDI. Other key research areas include membrane assisted capacitive deionization and chemically functionalized electrodes. While CDI has been touted as an efficient process for brackish water desalination, there remains intensive energy consumption to keep the traditional CDI process from becoming a transformational technology, and reverse osmosis continues to be more economical when desalinating higher concentration streams such as sea water. Many authors have discussed the possibility of parallel CDI operation with energy recovery to reduce energy requirements. However, beyond discharging a charged CDI cell into a resistive load, there has been little demonstration of CDI to CDI energy recovery. The interfacing of CDI cells offers not only the ability to lower the energy requirements, but also the possibility of semi-continuous CDI operation. In this work, parallel CDI cells are integrated with a multi-input bi-directional DC/DC converter to show active energy recovery from a discharging cell and subsequent deionization of a secondary cell using energy stored in the initial charged cell. Deionization experiments are conducted by closed-loop recirculation of a saline stream through the CDI cell to achieve a batch-mode configuration. The test system is equipped with inline conductivity probes for continuous monitoring of concentration. Along with the converter, the deionization system is connected to a power supply to compensate for losses and maintain operation. Initial testing was done by charging a primary cell at 1.2 V (Figure 1), and then directly connecting to a secondary cell. There were 12 and 7 µS/cm drops in concentration for the primary and secondary cells respectively. Future studies will track inter-cell energy transfer and show recovery of more than 50 % of the energy stored in the initial cell using this integrated CDI-converter setup.AcknowledgementsThe authors are thankful for the support of the State of Wyoming Advanced Conversion Technologies Task Force for supporting this research.