Type I X-ray bursts in the ultracompact binary 4U 1820–30 are powered by unstable thermonuclear burning of hydrogen-deficient material. We report detection 15 type from observed NICER between 2017 and 2023. All these occurred low state for persistent flux range 2.5–8 × 10 −9 erg s −1 cm −2 0.1–250 keV. The burst spectra during tail can be nicely explained blackbody model. However, first ~5 after onset, time-resolved showed strong deviations significant improvement fit obtained taking into...

Immobilized carbonic anhydrase (CA) enzyme enhances CO

Emissions of nitrogen oxides (NOX) in China are great concern because their impact on local air pollution as well regional environmental risks such acid rain, eutrophication, tropospheric ozone, fine particulate matter, and loss biodiversity. In this paper, total anthropogenic emissions NOX during the past two decades estimated basis commercial energy consumption emission factors different sectors fuel types. Specifically, inventories from 31 provinces, 7 economic sectors, 11 types 1995 to...

A novel potassium-carbonate-based absorption process is currently being developed to reduce the energy consumption when capturing CO2 from coal combustion flue gas. The employs enzyme carbonic anhydrase (CA) as a catalyst accelerate rate of absorption. This study focused on immobilization new variant CA onto group nonporous nanoparticles improve enzyme's thermal stability and its chemical resistance major impurities was manufactured at pilot scale by leading company. As carrier materials,...

Carbonic anhydrase (CA) enzyme-mediated absorption processes are regarded as promising alternatives to the conventional amine-based process for CO2 capture because of their low energy penalty and risk causing secondary pollution. The activity stability CA enzyme crucial reducing equipment operating costs process. This work investigated three cationic nonionic surfactants improve a technical-grade in 20 wt % potassium carbonate solution. Experimental results revealed that impact on depended...

Abstract The electrocatalytic conversion of 16‐electron multistep polysulfides is crucial for lithium–sulfur batteries, while it hard to achieve compatibility between intricate sulfur reduction processes and appropriate catalysts. Herein, a tandem strategy reported boost multi‐step intermediate reactions transformation by designing an electrocatalyst featuring cobalt zinc sites (Co/Zn), where the Zn serve as long‐chain lithium (LiPSs), promoting S 8 Li 2 4 ; Co accelerate kinetics subsequent...

An Integrated Vacuum Carbonate Absorption Process (IVCAP) for post-combustion carbon dioxide (CO2) capture is described. IVCAP employs potassium carbonate (PC) as a solvent, uses waste or low quality steam from the power plant CO2 stripping, and biocatalyst, carbonic anhydrase (CA) enzyme, promoting absorption into PC solution. A series of experiments were performed to evaluate activity CA enzyme mixed in solutions stirred tank reactor system under various temperatures, dosages, loadings,...

Abstract The reversible cycling of CaO adsorbents to CaCO 3 for high‐temperature CO 2 capture is substantially improved by mechanical treatment. milling intensity and conditions grinding (e.g., wet vs. dry, planetary vibratory milling) were determined be the main factors that control effectiveness mechanochemical synthesis enhance recycling stability sorbents prepared. In addition, MgO was used as an example inert binder help mitigate sintering. Wet into allowed efficient particle size...

Reactive dynamics simulations with the reactive force field (ReaxFF) were performed in NVE ensembles to study sintering of two solid calcium oxide (CaO) particles and without CO(2) chemisorption. The simulated conditions included starting adsorption temperatures at 1000 K 1500 particle separation distances 0.3 0.5 nm. results revealed that expansion sorbent during chemisorption was attributed CaO-CaO particles. Increasing temperature resulted more sintering. shorter distance between...

Nine fly ash samples were collected from the particulate collection devices (baghouse or electrostatic precipitator) of four full-scale pulverized coal (PC) utility boilers burning eastern bituminous coals (EB−PC ashes) and three cyclone either Powder River Basin (PRB) PRB blends (PRB−CYC ashes). As-received mechanically sieved to obtain six size fractions. Unburned carbon (UBC) content, mercury Brunauer−Emmett−Teller (BET)−N2 surface areas as-received ashes their fractions measured. In...

We report the ultrasonic spray pyrolysis (USP) synthesis and characterization of composite calcium oxide-based sorbents for carbon dioxide capture. Inclusion a small amount Al2O3 into CaO matrix (as low as Al/Ca: 0.03) yielded significant enhancement resistance to recycling degradation. The effective homogenous dispersion additives in relatively high surface area materials obtained via USP explain sorbent's performance. All were characterized by XRD, STEM, TEM, SEM, TGA (for CO2 uptake...

Two promising combustion modification approaches applicable to pulverized coal fired boilers are presented: "Oxygen-Enriched Combustion" (OEC) for NOx control and "Oxy-Combustion" (PC-OC) CO2 capture. Oxygen-enriched air rather than is used as an oxidizer in the OEC technology. Unlike flue gas treatment technologies, directly impacts formation process by significantly reducing conversion of bound nitrogen NOx. Pilot-scale full-scale tests have shown 20 30% reduction from optimized staged-air...

A novel absorption-based post-combustion CO2 capture process is being developed to reduce the energy use associated with stripping and compression. The features of a concentrated potassium carbonate/bicarbonate (PCB) aqueous solution as solvent high-pressure bicarbonate-dominant slurry enabled by crystallization CO2-rich solution. Vapor–liquid equilibrium data under typical conditions were measured tests performed various pressures, temperatures, PCB concentrations, loading levels using...