scholarly journals Sustainable Production of Reduced Phosphorus Compounds: Mechanochemical Hydride Phosphorylation Using Condensed Phosphates as a Route to Phosphite

Author(s):  
Feng Zhai ◽  
Tiansi Xin ◽  
Michael Geeson ◽  
Christopher Cummins

Phosphorus removal and recovery technologies have been implemented to tackle the anthropogenic eutrophication caused by phosphate runoff into waterways. In pursuit of a better utilization of the phosphates recovered from waste water treatment, we herein report that condensed phosphates can be employed to phosphorylate hydride reagents under solvent-free mechanochemical conditions to furnish phosphite (HPO3)2−, a versatile chemical with phosphorus in the +3 oxidation state. Hydride phosphorylation, as a two-electron one-proton reduction of a main group element oxide, constitutes a direct parallel with CO2 reduction to formate. Using potassium hydride as the hydride source, sodium trimetaphosphate (Na3P3O9 ), triphosphate (Na5P3O10), and pyrophosphate (Na4P2O7) engendered phosphite in 44, 58, and 44% yields based on total P content, respectively, under their optimal conditions. Formation of overreduced products including hypophosphite (H2PO2−) was identified as a competing process, and mechanistic investigation revealed that hydride attack on in situ generated phosphorylated phosphite species is a potent pathway for overreduction. The phosphite generated from our method could be easily isolated in the form of barium phosphite, a useful intermediate for production of phosphorous acid. This method circumvents the need to pass through white phosphorus (P4) as a high energy intermediate and mitigates involvement of environmentally hazardous chemicals. A bioproduced polyphosphate from baker’s yeast was demonstrated to be a viable starting material for the production of phosphite. This example demonstrates the possibility of accessing reduced phosphorus compounds in a more sustainable manner, and more importantly, closing the modern phosphorus cycle.

Author(s):  
Peter T. Smith ◽  
Sophia Weng ◽  
Christopher Chang

We present a bioinspired strategy for enhancing electrochemical carbon dioxide reduction catalysis by cooperative use of base-metal molecular catalysts with intermolecular second-sphere redox mediators that facilitate both electron and proton transfer. Functional synthetic mimics of the biological redox cofactor NADH, which are electrochemically stable and are capable of mediating both electron and proton transfer, can enhance the activity of an iron porphyrin catalyst for electrochemical reduction of CO<sub>2</sub> to CO, achieving a 13-fold rate improvement without altering the intrinsic high selectivity of this catalyst platform for CO<sub>2</sub> versus proton reduction. Evaluation of a systematic series of NADH analogs and redox-inactive control additives with varying proton and electron reservoir properties reveals that both electron and proton transfer contribute to the observed catalytic enhancements. This work establishes that second-sphere dual control of electron and proton inventories is a viable design strategy for developing more effective electrocatalysts for CO<sub>2</sub> reduction, providing a starting point for broader applications of this approach to other multi-electron, multi-proton transformations.


Nanoscale ◽  
2021 ◽  
Author(s):  
Woong Choi ◽  
Joon Woo Park ◽  
Woonghyeon Park ◽  
Yousung Jung ◽  
Hyunjoon Song

Electrochemical CO2 reduction reaction (eCO2RR) has been considered one of the potential technologies to store electricity from renewable energy sources into chemical energy. For this aim, designing catalysts with high...


1994 ◽  
Vol 266 (5) ◽  
pp. C1257-C1262 ◽  
Author(s):  
Y. Ohira ◽  
K. Saito ◽  
T. Wakatsuki ◽  
W. Yasui ◽  
T. Suetsugu ◽  
...  

Responses of beta-adrenoceptor (beta-AR) in rat soleus to gravitational unloading and/or changes in the levels of phosphorus compounds by feeding either creatine or its analogue beta-guanidinopropionic acid (beta-GPA) were studied. A decrease in the density of beta-AR (about -35%) was induced by 10 days of hindlimb suspension, but the affinity of the receptor was unaffected. Suspension unloading tended to increase the levels of adenosine triphosphate and phosphocreatine and decrease inorganic phosphate. Even without unloading, the beta-AR density decreased after an oral creatine supplementation (about -20%), which also tended to elevate the high-energy phosphate levels in muscle. However, an elevation of beta-AR density was induced (about +36%) after chronic depletion of high-energy phosphates by feeding beta-GPA (about +125%). Data suggest that the density of beta-AR in muscle is elevated if the high-energy phosphate contents are chronically decreased and vice versa. However, it may not be directly related to the degree of muscle contractile activity.


2011 ◽  
Vol 6 (4) ◽  
Author(s):  
Christophe Amiel ◽  
Delphine Nawawi-Lansade ◽  
Kim Sorensen

Many recent studies have shown processes or models to minimize the energy consumption on a municipal wastewater treatment plant (WWTP) in operation. Today the main drivers are the energy and CO2 reduction. On existing plants, the potential success of achieving the Energy neutral WWTP depends on the effluent guarantees demanded and the eventual additional carbon sources on the digesters. Veolia has now developed a tool to estimate the energy consumption and the CO2 impact to select the appropriate treatment lines (water and sludge) up front at the project stage. The real challenge is to cover the needs of the plant without external carbon sources added to the digester. At the project stage, before the bid of the WWTP, due to time constraints only few comparisons can be performed to predict the energy consumption and CO2 impact and provide the best solution to reach to the energy neutral plant as electricity wise. One conclusion of the study is that, the raw water characteristics and the effluent guarantee has a great impact on the possibilities to reach the target. Furthermore, working on reducing the power consumption and on increasing the biogas production for example by a continuous Thermal hydrolysis is a good way to go towards self sufficiency.


2018 ◽  
Vol 10 (9) ◽  
pp. 3254 ◽  
Author(s):  
Miguel-Angel Perea-Moreno ◽  
Francisco Manzano-Agugliaro ◽  
Quetzalcoatl Hernandez-Escobedo ◽  
Alberto-Jesus Perea-Moreno

The peanut (Arachys hypogaea) is a plant of the Fabaceae family (legumes), as are chickpeas, lentils, beans, and peas. It is originally from South America and is used mainly for culinary purposes, in confectionery products, or as a nut as well as for the production of biscuits, breads, sweets, cereals, and salads. Also, due to its high percentage of fat, peanuts are used for industrialized products such as oils, flours, inks, creams, lipsticks, etc. According to the Food and Agriculture Organization (FAO) statistical yearbook in 2016, the production of peanuts was 43,982,066 t, produced in 27,660,802 hectares. Peanuts are grown mainly in Asia, with a global production rate of 65.3%, followed by Africa with 26.2%, the Americas with 8.4%, and Oceania with 0.1%. The peanut industry is one of the main generators of agroindustrial waste (shells). This residual biomass (25–30% of the total weight) has a high energy content that is worth exploring. The main objectives of this study are, firstly, to evaluate the energy parameters of peanut shells as a possible solid biofuel applied as an energy source in residential and industrial heating installations. Secondly, different models are analysed to estimate the higher heating value (HHV) for biomass proposed by different scientists and to determine which most accurately fits the determination of this value for peanut shells. Thirdly, we evaluate the reduction in global CO2 emissions that would result from the use of peanut shells as biofuel. The obtained HHV of peanut shells (18.547 MJ/kg) is higher than other biomass sources evaluated, such as olive stones (17.884 MJ/kg) or almond shells (18.200 MJ/kg), and similar to other sources of biomass used at present for home and industrial heating applications. Different prediction models of the HHV value proposed by scientists for different types of biomass have been analysed and the one that best fits the calculation for the peanut shell has been determined. The CO2 reduction that would result from the use of peanut shells as an energy source has been evaluated in all production countries, obtaining values above 0.5 ‰ of their total emissions.


2021 ◽  
Author(s):  
Qinying Pan ◽  
Mohamed Abdellah ◽  
Yuehan Cao ◽  
Yang Liu ◽  
Weihua Lin ◽  
...  

Abstract Rhenium(I)-carbonyl-diimine complexes are promising photocatalysts for CO2 reduction. Covalent organic frameworks (COFs) can be perfect sensitizers to enhance the reduction activities. Here we investigated the excited state dynamics of COF (TpBpy) with 2,2'-bipyridine incorporating Re(CO)5Cl (Re-TpBpy) to rationalize the underlying mechanism. The time-dependent DFT calculation first clarified excited state structure of the hybrid catalyst. The studies from transient visible and infrared spectroscopies revealed the excitation energy-dependent photo-induced charge transfer pathways in Re-TpBpy. Under low energy excitation, the electrons at the LUMO level are quickly injected from Bpy into ReI center (1–2 ps) followed by backward recombination (13 ps). Under high energy excitation, the hot-electrons are first injected into the higher unoccupied level of ReI center (1–2 ps) and then slowly relax back to the HOMO in COF (24 ps). There also remains long-lived free electrons in the COF moiety. This explained the excitation energy-dependent CO2 reduction performance in our system.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1040 ◽  
Author(s):  
Spyridon Achinas ◽  
Gerrit Euverink

Anaerobic technology is a well-established technique to wean the fossil fuel-based energy off with various positive environmental inferences. Biowaste treatment is favorable due to its low emissions. Biogas is merely regarded as the main product of anaerobic digestion with high energy value. One of the key concerns of the waste water treatment plants is the vast amount of cellulosic residuals produced after the treatment of waste waters. The fine sieve fraction, collected after the primary sludge removal, has great energy value. In this study, the economic performance of a biogas plant has been analyzed based on net present value and pay-back period concepts. The plant in the base scenario produced 309,571 m3 biogas per year. The annual electricity production has been 390,059 kWh. The producible heat energy has been 487,574 kWh or 1755 GJ per year. The plant depicts a positive economic situation with 11 years pay-back time, earning low profits and showing a positive net present value of 11,240 €.


1998 ◽  
Vol 5 (3) ◽  
pp. 168-175 ◽  
Author(s):  
Herman Winick

Many of the more than 40 operational light sources around the world have achieved performance levels that exceed initial design goals. These accomplishments are reviewed, along with concepts and proposals for sources with performance levels exceeding those of present sources. These include storage rings with lower electron-beam emittance than present third-generation rings and free-electron lasers (FELs). It now appears that the highest performance sources will be based on linacs rather than storage rings. This is because emittance originates differently and scales differently with electron energy for rings and linacs, so that the lowest electron-beam emittance can be achieved in high-energy linacs equipped with high-brightness electron sources. Such electron beams can be used to provide X-ray beams with very high brightness and coherence in sub-picosecond pulses in a single pass through a small-gap short-period undulator by spontaneous emission, and with even higher beam brightness and coherence by stimulated coherent emission in an FEL. Designs for such FEL sources, and associated research and development, are underway at several laboratories.


1968 ◽  
Vol 25 (8) ◽  
pp. 1525-1538 ◽  
Author(s):  
Sandra S. Nowlan ◽  
W. J. Dyer ◽  
Doris I. Fraser

Extraction of cod muscle with 0.3 N perchloric acid followed by digestion of the residue in potassium hydroxide yielded an average of 16% more total glycogen than did classical digestion with 30% KOH. However, the differences tended to be less at higher glycogen levels. It was suggested that glycogen may be partially degraded during digestion with KOH, although no glycogenosis occurred during contact with alkali prior to heating. The proportion of residual glycogen not extracted by acid varied from 23% in unfrozen muscle to about 40% in liquid nitrogen-frozen and in slowly frozen muscle.Significant degradation of glycogen and high energy phosphorus compounds in frozen prerigor cod muscle was avoided by weighing samples in insulated beakers chilled by liquid nitrogen to prevent warming or thawing, and by homogenizing immediately on addition of acid extractant. Extraction with acid enabled the simultaneous determination of glycogen and phosphorus compounds on the same sample. Special sampling procedures were employed to reduce the sampling error due to variation in glycogen distribution along the fillet.


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