Energetic Feasibility Research Articles

Energy recovery from tubular microbial electrolysis cell with stainless steel mesh as cathode

In comparison to the transportation and storage of hydrogen, methane has advantages in the practical application, while the emerging product termed as ‘biohythane’ could be an alternative to pure hydrogen or methane in a new form of energy recovery from microbial electrolysis cell (MEC). However, the cathodic catalyst even for biohythane still bothers the performance and cost of total MEC. Herein, we fabricated the MEC reactor with surrounding stainless steel mesh (SSM) to investigate the feasibility of stainless steel mesh as an alternative to precious metal in biohythane production. The columbic efficiency (CE) of anode was around at 80%, representing the SSM would not limit the activity of anodic biofilm; the SEM image and ATP results accordingly indicated the anodic biofilm was mature and well constructed. The main contribution of methanogens that quantified by qPCR belonged to the hydrogenotrophic group (Methanobacteriales) at cathode. The energy efficiency reached more than 100%, reached up to approximately 150%, potentially suggesting the energetic feasibility of the application to obtain biohythane with SSM in scale-up MEC. Benefiting from the likely tubular configuration, the ohmic resistance of cathode was very low, while the main limitation associated with charge transfer was mainly caused by biofilm formation. The total performances of SSM used in the tubular configuration for biohythane production provide an insight into the implementation of non-precious metal in future scale-up pilot with energy recovery.

Energetic analyses of installing SOFC co-generation systems with EV charging equipment in Japanese cafeteria

Energetic feasibility analyses were conducted when an SOFC CGS with EV charging equipment is installed in a facility with a high hot-water demand and a high thermo-electric demand ratio. The university cafeteria located on the Hitachi Campus of Ibaraki University in Japan was selected as an installation target because its electric and hot-water demands fulfilled the intended criterion of a high thermo-electric demand ratio. It was made clear that the merits of a co-generation system are not optimal in the case a gas water heater is selected as the backup hot-water supply. To solve the problems contributing to this bad result and to improve the performance, the authors next selected a heat pump water heater as the backup hot-water supply. It was made clear that this system possesses sufficiently high energy savings performance. It was also shown that the coexistence and co-prosperity of the cafeteria and EV charging equipment are successfully achieved. These results reveal that an SOFC CGS with EV charging equipment can be a feasible candidate for a future energy supply system installed in Japanese cafeteria, which is a facility with a large hot-water demand and a high thermo-electric demand ratio, by adopting a heat pump water heater, instead of the usual gas water heater, as the backup hot-water supply.

Abstract LB-016: Angiogenin contributes to bladder cancer tumorigenesis by facilitating p53 mediated activation of MMP2

Abstract Angiogenin (ANG) has been reported to be upregulated and associated with poor prognosis in some human cancers. Previous studies revealed ANG expression stimulated matrix metallopeptidase-2 (MMP2) expression through a) phosphorylation of ERK1/2 (ANG-ERK1/2-MMP2 pathway), which led to a pronounced tumorigenesis, and b) hypomethylation of the MMP2 gene by negatively regulating DNA methyltransferase 3b (DNMT3b) expression (ANG-DNMT3b-MMP2 pathway). However, since ANG-DNMT3b-MMP2 pathway is independent of ANG-ERK1/2-MMP2, the exact mechanism through which ANG-induced MMP2 expression remains unclear. Here we show that ANG-induced p53 expression is regulated by ERK1/2 and is a missing link between ERK1/2 and MMP2 in ANG-ERK1/2-MMP2 axis. The analysis of the serial deletion mutant MMP2 promoters demonstrated that the p53-binding site is critical for ANG to induce MMP2 promoter activity. We also found that ANG increased the DNA binding activity of p53, which was suppressed by knockdown of p53 leading to the reduction in MMP2 expression. Remarkably, we revealed that mutated p53 isoforms were able to induce MMP2 expression, illustrating that in this setting, the primary driver of MMP2 expression is the amount of p53 protein (wild-type and mutants) available to bind to the MMP2 promoter. ChIP-qPCR and promoter assay using MMP2 promoter constructs confirmed that both wild-type and p53 mutants (V143A, R175H, R248W, R249S and R273H) increased MMP2 promoter transcriptional activities in BCa cell lines. We also performed computational modeling to support energetic and structural feasibility of our wild-type and mutant p53 observations. We predicted that p53 mutants can bind to p53 binding sites on the MMP2 promoter with binding energy comparable to wild type. The mutants may have induced, however, changes on the expression of other p53 targets. In addition, we present data that the p53 mutants are able to induce cell growth in bladder cells, in opposition to the wild type p53. Finally, the results from human bladder tumors a) confirmed the strong correlation between ANG, p53 and MMP2 and b) reduced survival when ANG, p53 and/or MMP2 were overexpressed in human bladder tumors. We provide multiple lines of evidence indicting ANG oncogenic potential. Thus, we suggest that targeting ANG and associated factors could provide a novel strategy to inhibit tumor angiogenesis and growth. Citation Format: Rafael Peres, Hideki Furuya, Kanani Hokutan, Yoshiko Shimizu, Owen T. Chan, Ian Pagano, Lars Dyrskjøt, Jørgen B. Jensen, Per-Uno Malmström, Ulrika Segersten, Ho Leung Ng, Filip Janku, Charles J. Rosser. Angiogenin contributes to bladder cancer tumorigenesis by facilitating p53 mediated activation of MMP2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-016. doi:10.1158/1538-7445.AM2017-LB-016

Design and optimization of a novel solar cooling system for combined cycle power plants

This paper presents the design of a novel Solar Assisted Combined Cycle power plant. The system includes a solar loop equipped with a double stage absorption chiller driven by high-temperature high-vacuum non-concentrating flat-plate solar thermal collectors. The solar loop is coupled to a single-pressure Combined Cycle power plant. The cooling energy produced by the absorption chiller is used to cool gas turbine inlet air, aiming at enhancing system efficiency and electrical capacity. This Solar Assisted Combined Cycle arrangement is analysed through a dynamic system simulation and a thermoeconomic analysis is also performed aiming at determining the optimal set of design and operating parameters. The paper has the objective to prove the technical, energetic and economic feasibility of this technology, especially for hot and dry areas, with respect to other alternative air cooling configurations. In addition, solar collectors operating temperatures are high enough to drive a two stage absorption chiller, showing a Coefficient of Performance roughly two times higher than the one of a conventional single stage absorption chiller. This original configuration was numerically analysed in TRNSYS environment, developing a suitable dynamic simulation model in order to predict system performances. Suitable dynamic models are implemented for all the components included in the system. Special attention is also paid to the design of novel control strategies aiming at maximizing the utilization of solar energy for cooling purposes. In particular, a special control strategy managing cooling water flow is implemented in order to limit as much as possible water condensation within the cooling coil. The simulation also includes a detailed thermoeconomic model which accurately evaluates system capital and operating costs as a function of design and operating parameters. The simulations results show that a very high thermal efficiency of solar collectors, on average equal to 34%, is achieved. Results from the economic point of view were also satisfactory. In fact, the pay back period was about 8 years in the best case. Finally, in order to analyse the effects of the variation of the main design parameters, a parametric analysis is also presented. Such analysis shows that high solar radiation and low ambient humidity are crucial in order to achieve acceptable economic profitability indexes.

Energetic and Economic Feasibility of RDF to Energy Plant for a Local Thai Municipality

Abstract Management of waste is a main concern and one of the most crucial issues in modern society. Effective waste management considers prevention, recycling, and handling of waste in such a way that most effectively protects human health and the environment. Energy recovery is one of the accepted options in managing solid waste. In the present paper, a waste-to-energy conversion plant utilizing refuse derived fuel (RDF) with appropriate combustion technology was proposed for a local municipality in Lampang, Thailand. Realistic waste quantity and composition were estimated. Mass and energy analyses as well as an economic feasibility survey were carried out to evaluate performance and benefits of the proposal. With up to 220 tons of RDF available daily, it was suggested that a power plant project between 5 to 13 MWe generation capacity may be developed. For a baseline case of 5 MWe, the project is economically feasible with tolerance to ± 50% fluctuation in total capital cost, electricity sale price and tipping fee.

The Solubility of Ba in a New Cs Waste Form, Cs2TiNb6O18

ABSTRACTWe report experimental and computational studies of Ba doping for Cs in Cs2TiNb6O18, a material with potential to be an exceptional ceramic waste form for Cs sequestration. Three co-doping (simultaneous metal reduction for charge balance of Ba2+ for Cs+) schemes have been experimentally tested: Ti4+ for Nb5+, Ti3+ for Ti4+ and Nb4+ for Nb5+. Unfortunately, none showed conclusively that the co-substitution was successful. Atomistic modelling was then performed on all three schemes using novel potentials to assess the energetic feasibility, from these the most favourable scenario is reduction of Nb5+ to Nb4+.

Analysis on the performance of a high efficiency administrative building in Spain

ABSTRACTA building is an element that consumes great quantities of primary energy both during construction and operating life. Buildings are reported to consume 40% of total primary energy in Europe. Efficiency and saving policies in this sector should be priority to reduce the European energetic dependence on third countries as well as to diminish greenhouse emissions.The present work is aimed at review the results obtained during the first operating year of a public building with high energetic qualification in Mérida (Spain), which develops novel techniques on efficiency, energy saving and integration of renewable energies applied to the building sector. The building was constructed according to the climatic characteristics of Mérida. Diverse techniques regarding passive solar collection and thermal isolation, window and roofing shadowing and natural lighting were accounted for.The results showed that it is possible to air-condition public buildings in extreme weather regions by applying specific measures to minimize energy consumption with the use of renewable energy sources (solar energy and biomass). Based on the actual energetic results, the economic, energetic, and environmental feasibility of this kind of building is also analyzed.

Tannic Acid Selectively Extracting Titanium from Ilmenite: Experimental and Theoretical Investigation

A novel route of extracting titanium using tannic acid from ilmenite was investigated. The strong affinity of tannic acid towards metal ions having high oxidation states was explored to extract titanium selectively from a multi-element solution prepared by dissolving ilmenite in sulphuric acid and ammonium sulphate. Titanium-tannic acid complex was selectively precipitated from the multi-element solution at pH 4.5. The precipitate was separated by vacuum filtration and the filter cake was washed with 2% hydrochloric acid solution, deionized water and isopropyl alcohol after filtration. The washed filter cake was dried at room temperature and ground into powder on drying. The titaniumtannic acid complex so obtained was composed of 98.6% of titanium, 0.2% of iron and 1.2% of other impurities. The density functional theory simulation at B3LYP method with a basis of 6-31G was also conducted to verify optimized structure and its stability. The result showed energy gap of 2.43 eV between two frontier orbitals (highest occupied molecular orbitals and lowest unoccupied molecular orbitals), which is large enough to indicate energetic feasibility of the complex formation.

Superstructure optimization and energetic feasibility analysis of process of repetitive extraction of hydrocarbons from Botryococcus braunii – a species of microalgae

Microalgae are potential resources for producing renewable fuel; however, the process of fuel production from microalgae is itself highly energy consuming and not commercially feasible, yet. Repetitive non-destructive extraction, also called repetitive milking, is a novel method for production of hydrocarbons from Botryococcus braunii – a species of microalgae. In this study, superstructure optimization technique is used to analyse the energetic feasibility of the repetitive milking process and to find the suitable technology options for each stage involved. The repetitive milking process is found to be energetically positive with an average net energy ratio of two for the optimum route. Open pond, cylindrical sieve rotator filter and nanofiltration were found to be the optimum technologies for growth and hydrocarbon production, dewatering and solvent recovery stages, respectively. Belt filter press and vibratory screen filter for dewatering and distillation for solvent recovery are also found to be energetically feasible technologies.

Effect Of Phases On The Energetics Of Pristine InP Nanowires: An Ab-initio Approach

We have investigated the electronic and structural properties of pristine Zinc-blende type InP nanowires (NWs) by using ab-initio approach. We have considered the effect of phases by taking NWs of 7 A radii in three phases viz. (100), (110), (111). It is revealed that the electronic properties of NWs are highly affected by the wire phases. NW in (100) phase is found to be semiconducting with an indirect band gap of 0.71 eV whereas it becomes semi-metallic and metallic in other two phases. Thus, the nature of nanowires is observed as a function of NW phases. Further, energetic feasibility of InP NWs strongly dependent on their growth phase. Copyright © 2016 VBRI Press.

Quenching of pH-Responsive Luminescence of a Benzoindolizine Sensor by an Ultrafast Hydrogen Shift.

Fluorescent-sensor design requires consideration of how photochemical dynamics control properties of a sensing state. Transient absorption (TA) spectroscopy reveals an ultrafast net [1,3]-hydrogen shift following excitation of a protonated methoxy benzoindolizine (bzi) sensor in solution. These photochemical dynamics explain a quenched pH-responsive fluorescence shift and dramatically reduced fluorescence quantum yield relative to other (e. g. methyl) bzi compounds that do not tautomerize. Calculations predict the energetic and structural feasibility for rearrangement in protonated bzi compounds, such that interaction between the pi-network and strongly electron-donating methoxyl must lower the barrier for suprafacial H or H+ shift across an allylic moiety. As bzi compounds broadly exhibit pH-responsive emission shifts, chemical interactions that modulate this electronic interaction and suppress tautomerization could be used to facilitate binding- or surface-specific acid-responsive sensing.

Characterizing the Structures, Spectra, and Energy Landscapes Involved in the Excited-State Proton Transfer Process of Red Fluorescent Protein LSSmKate1.

By applying molecular dynamics (MD) simulations and quantum chemical calculations, we have characterized the states and processes involved in the excited-state proton transfer (ESPT) of LSSmKate1. MD simulations identify two stable structures in the electronic ground state of LSSmKate1, one with a protonated chromophore and the other with a deprotonated chromophore, thus leading to two separate low-energy absorption maxima with a large energy spacing, as observed in the calculated and experimentally measured absorption spectra. Proton transfer is induced by electronic excitation. When LSSmKate1 is excited, the electrons in the chromophore are transferred from the phenol ring to the N-acylimine moiety; the acidity of a phenolic hydroxyl group is thus enhanced. The calculated potential energy curves (PECs) exhibit energetic feasibility in the generation of the fluorescent species in LSSmKate1, and the exact agreement between the calculated and experimentally measured values of the large Stokes shift further provides solid theoretical evidence for the ESPT process taking place in photoexcited LSSmKate1. The molecular environments play a significant role in the geometries and absorption/emission energies of the chromophores. Overall, TD-ωB97X-D/molecular mechanics (MM) provides a better description of the optical properties of LSSmKate1 than TD-B3LYP/MM, although it always overestimates the excitation energies.

ChemInform Abstract: Montecrinanes A—C: Triterpenes with an Unprecedented Rearranged Tetracyclic Skeleton from Celastrus vulcanicola. Insights into Triterpenoid Biosynthesis Based on DFT Calculations.

Three new triterpenoids with an unprecedented 6/6/6/6-fused tetracyclic carbon skeleton, montecrinanes A-C (1-3), were isolated from the root bark of Celastrus vulcanicola, along with known D:B-friedobaccharanes (4-6), and lupane-type triterpenes (7-12). The stereostructures of the new metabolites were elucidated based on spectroscopic (1D and 2D NMR) and spectrometric (HR-EIMS and HR-ESIMS) techniques. Their absolute configurations were determined by both NMR spectroscopy, with (R)-(-)-α-methoxyphenylacetic acid as a chiral derivatizing agent, and biogenetic considerations. Biogenetic pathways for montecrinane and D:B-friedobaccharane skeletons were proposed and studied by DFT methods. The theoretical results support the energetic feasibility of the putative biogenetic pathways, in which the 1,2-methyl shift from the secondary baccharenyl cation represents a novel and key reaction step for a new montecrinane skeleton.

First principles model calculations of the biosynthetic pathway in selinadiene synthase

Terpenes comprise the largest class of natural products currently known. These ubiquitous molecules are synthesized by terpene synthases via complex carbocationic reactions, incorporating highly reactive intermediates. In the current study, we present a mechanistic investigation of the biosynthetic pathway for the formation of selina-4(15),7(11)-diene. We employ density functional theory to study a model carbocation system in the gas-phase, and delineate the energetic feasibility of a plausible reaction path. Our results suggests that during formation of selina-4(15),7(11)-diene, the substrate is likely folded in a conformation conducive to sequential cyclizations. We propose that a required proton transfer cannot occur intramolecularly in the gas-phase due to a high free energy barrier, and that enzyme assistance is essential for this step. Hybrid quantum mechanics-molecular mechanics docking studies suggest that enzyme intervention could be realized through electrostatic guidance.

Assessment of Solar‐to‐Fuels Strategies: Photocatalysis and Electrocatalytic Reduction

AbstractThe production of fuels in a solar refinery by the nonbiological conversion of CO2 and water is a potential sustainable solution to meet our future energy needs. We develop a general process model for a solar refinery that allows us to assess the energetic and economic feasibility of a specific process. We demonstrate the utility of this model by analyzing two specific cases: 1) the photocatalytic conversion and 2) the photovoltaic‐powered electrocatalytic reduction of CO2 to yield a methanol product. From the analysis, we posit specific catalytic, reaction engineering, process engineering, and solar utilities targets to compete with industrial methanol production. For the photocatalytic process, the most important challenge is to improve the solar‐to‐fuels efficiency to at least 15 %, whereas for the electrocatalytic reduction process, even with much improved current density, cell potential, and reaction selectivity, the process will be ultimately limited by the price of solar (or other renewable) electricity.

Montecrinanes A-C: Triterpenes with an Unprecedented Rearranged Tetracyclic Skeleton from Celastrus vulcanicola. Insights into Triterpenoid Biosynthesis Based on DFT Calculations.

Three new triterpenoids with an unprecedented 6/6/6/6-fused tetracyclic carbon skeleton, montecrinanes A-C (1-3), were isolated from the root bark of Celastrus vulcanicola, along with known D:B-friedobaccharanes (4-6), and lupane-type triterpenes (7-12). The stereostructures of the new metabolites were elucidated based on spectroscopic (1D and 2D NMR) and spectrometric (HR-EIMS and HR-ESIMS) techniques. Their absolute configurations were determined by both NMR spectroscopy, with (R)-(-)-α-methoxyphenylacetic acid as a chiral derivatizing agent, and biogenetic considerations. Biogenetic pathways for montecrinane and D:B-friedobaccharane skeletons were proposed and studied by DFT methods. The theoretical results support the energetic feasibility of the putative biogenetic pathways, in which the 1,2-methyl shift from the secondary baccharenyl cation represents a novel and key reaction step for a new montecrinane skeleton.

Energetic and economic feasibility analysis of utilizing waste heat from incineration facility and power plant for large-scale horticulture facilities

The Korean government plans to establish large-scale horticultural facilities using reclaimed land to improve the competitiveness of the national agricultural sector at the government level. One of the most significant corresponding problems is the ongoing dependence of these facilities on fossil fuel, whereby constant heating is necessary during the winter season to provide the necessary breeding conditions for greenhouse crops. This study investigated the potential applicability of waste heat from incineration facility and power plant for use in large-scale horticultural facilities by evaluating the hot-water temperature, heat loss and life cycle cost as functions of the pipe material and distance between the heat source and the greenhouse. In case of utilizing waste heat from incineration facility, providing heating for greenhouse crop under high temperature set-point with HDPE pipe turned out to be the most economical method, which showed the equipment cost of approximately $4,300,000, annual energy saving cost of approximately $600,000 during winter season and the payback period of approximately 7.16years based on 16km distance.

Effect of moisture on pretreatment efficiency for anaerobic digestion of lignocellulosic substrates

The present study evaluates the effect of moisture in low-temperature and ultrasound pretreatment on lignocellulosic substrates anaerobic biodegradability, where brewer’s spent grain was used as model substrate. Besides moisture content, low-temperature pretreatment was also evaluated in terms of temperature (60–80°C) and exposure time (12–72h). Likewise, ultrasonication was also evaluated in terms of specific energy (1000–50,000kJkgTS−1). In addition, the effect of substrate particle size reduction by milling pretreatment was also considered. The results clearly demonstrated that substrate moisture (total solid concentration) is a significant parameter for pretreatment performance, although it has been rarely considered in pretreatment optimisation. Specifically, moisture optimisation increased the methane yield of brewer’s spent grain by 6% for low-temperature pretreatment (60°C), and by 14% for ultrasound pretreatment (1000kJkgTS−1) towards the control (without pretreatment). In both pretreatments, the experimental optimum total solid concentration was 100gTSkg−1. Thus, lowering substrate moisture, a strategy suggested attaining energetic pretreatment feasibility, needs to be analysed as another pretreatment variable since it might have limited correlation. Finally, a preliminary energetic balance of the pretreatments under study showed that the extra methane production could not cover the energetic pretreatment expenses.

Minimising microbubble size through oscillation frequency control

Microbubbles are bubbles below 1mm in size and have been extensively deployed in industrial settings to improve gaseous exchange between gas and liquid phases. The high surface to volume ratio offered by microbubbles enables them to enhance transport phenomena and therefore can be used to reduce energy demands in many applications including, waste water aeration, froth flotation, oil emulsion separations and evaporation dynamics. Microbubbles can be produced by passing a gas stream through a micro-porous diffuser placed at the gas–liquid interface. Previous work has shown that oscillating this gas steam can reduce the bubble size and therefore increase energy savings. In this work we show that it is possible to further reduce microbubble size (and consequently maximise the number of bubbles) by varying the frequency of the oscillating gas supply. Three different microbubble generation systems have been investigated; an acoustic oscillation system and a mesh membrane, a fluidic oscillator coupled to a single orifice membrane and a fluidic oscillator coupled to a commercially available ceramic diffuser. In all three bubble generation methods there is an optimum oscillation frequency at which the bubble size is minimised and the number of microbubbles maximised. In some cases a reduction in bubble size of up to 73% was achieved compared with non-optimal operating frequencies. The frequency at which this optimum occurs is dependent on the bubble generation system; more specifically the geometry of the system, the type micro-porous diffuser and the gas flow rate. This work proves that by tuning industrial microbubble generators to their optimal oscillation frequency will result in a reduction of microbubble size and increase their number density. This will further improve gaseous exchange rates and therefore improve the efficiency of the industrial processes where they are being employed to produce bubbles, leading to a reduction in associated energy costs and an increase in the overall economic and energetic feasibility of these processes.

Optimization of a thermoelectric system for power generation realized by “hidden” components

Today the utilization of renewable energy sources is very important to support the traditional ones, and also in order to reach the objectives fixed by the Kyoto Protocol.In this context, also well-known technologies related to the electric energy production, formerly not suitable – due to the poor technological level of the components or due to the high costs linked to the system efficiency – may now find a suitable collocation.Among these technologies, the thermoelectric effect may be very advantageous in some particular applications of small power. A power generation system utilizing this technology has been studied by the authors. This system utilizes the thermal difference between a lower temperature sink, e.g. a water reservoir, and a higher temperature source, such as exhaust heat (e.g. from industrial processes) or as produced by solar energy captured by an extended surface. The thermoelectric generator is made up of thermocouples placed on the internal surface of a tubular heat exchanger, located inside the water body and filled up with hot water coming from the energy source.In this paper, the physical mechanisms and the energy balances governing the system are described in order to evaluate its energetic feasibility. Once fixed, the electrical power required by the end user, the system parameters are optimized with the aim to have the most compact equipment and components. A simulation of the proposed system was performed referring to the city of Palermo, Italy. A very poor economic convenience of the system has been found in this applications.