Propylene Research Articles

THE INFLUENCE OF INTAKE VALVE CLOSE TIMING ON THE ENVIRONMENTAL PERFORMANCE OF A SPARK IGNITION ENGINE USING GASOLINE AND NATURAL GAS

The tightening of environmental requirements has forced car manufacturers to look for various ways to reduce exhaust gas emissions. The existing structural solutions of internal combustion engines allow this type of pollution to be reduced by adjusting the intake valve timing. This is especially relevant when it comes to reducing spark ignition engine emissions when using natural gas as fuel. In this study, a wide range of intake valve timing adjustments from 24° to 54° every six crank angle degrees was taken at a constant engine speed (n = 2500 rpm) and different loads and fixed excess air ratios (λ = 1). The changes in oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), nitrous oxide (NOx), methane (CH4), and propane (C3H8) gas emissions were observed in the aforementioned intake valve timing range.

Ultra-Low-Cost Disposable Hand-Held Clinical-Scale Propane Gas Hyperpolarizer for Pulmonary Magnetic Resonance Imaging Sensing.

Hyperpolarized magnetic resonance imaging (MRI) contrast agents are revolutionizing the field of biomedical imaging. Hyperpolarized Xe-129 was recently FDA approved as an inhalable MRI contrast agent for functional lung imaging sensing. Despite success in research settings, modern Xe-129 hyperpolarizers are expensive (up to $1M), large, and complex to site and operate. Moreover, Xe-129 sensing requires specialized MRI hardware that is not commonly available on clinical MRI scanners. Here, we demonstrate that proton-hyperpolarized propane gas can be produced on demand using a disposable, hand-held, clinical-scale hyperpolarizer via parahydrogen-induced polarization, which relies on parahydrogen as a source of hyperpolarization. The device consists of a heterogeneous catalytic reactor connected to a gas mixture storage can containing pressurized hyperpolarization precursors: propylene and parahydrogen (10 bar total pressure). Once the built-in flow valve of the storage can is actuated, the precursors are ejected from the can into a reactor, and a stream of hyperpolarized propane gas is ejected from the reactor. Robust operation of the device is demonstrated for producing proton sensing polarization of 1.2% in a wide range of operational pressures and gas flow rates. We demonstrate that the propylene/parahydrogen gas mixture can retain potency for days in the storage can with a monoexponential decay time constant of 6.0 ± 0.5 days, which is limited by the lifetime of the parahydrogen singlet spin state in the storage container. The utility of the produced sensing agent is demonstrated for phantom imaging on a 3 T clinical MRI scanner located 100 miles from the agent/device preparation site and also for ventilation imaging of excised pig lungs using a 0.35 T clinical MRI scanner. The cost of the device components is less than $35, which we envision can be reduced to less than $5 for mass-scale production. The hyperpolarizer device can be reused, recycled, or disposed.

Frequency Response Method for Diffusivity Characterization of Propane in HZSM-5

Transient uptake curves for propane gas in a bed of HZSM-5 using a volumetric frequency response setup (batch system) were obtained. Thereby, a perturbation, such as a change in volume, was applied to the solid/gas system, and the resulting change in pressure was detected. Two cases of mass transfer limitations (bed diffusion control and micropore diffusion control) were compared, and it was concluded that, in the presented case, micropore diffusion is the rate-determining process. The obtained micropore diffusion coefficient for propane in HZSM-5 was, on average, about 1.2 × 10−10 m2 g−1, which is in good agreement with other frequency response studies shown by literature data. The homemade setup and the modeling presented in this work serve as the basis for ongoing numerical simulations.

Experimental and numerical study on fire extinguishing by water spray

This study clarified the conditions under which a gas fire is extinguished by spraying water. In the experiments, a water spray nozzle positioned 1 m directly above a propane gas burner was activated while gradually increasing the operating pressure and flow rate of the nozzle. The fire experiments with water spray were also numerically simulated by Fire Dynamics Simulator (FDS) with the extinction model based on the concept of a critical flame temperature. The volumetric flow rate required for extinguishing was clarified by the experiments and the simulation under several conditions; the rate predicted by the FDS was smaller than that measured by the experiments. This discrepancy may have been due to the effect of the rim of the gas burner.

Experimental study on the morphology of turbulent diffusion flames with different aspect ratios under slope conditions

In this paper, the morphology of turbulent diffusion flames with varying aspect ratios under slope conditions was investigated. A simulated fire source using propane gas with an area of 80 cm2 was utilized. The influences of slope angle and aspect ratio of the fire source on the flame tilt angle (between the plume centerline and the slope), flame length, and flame height were systematically studied. The aspect ratio of the fire source (L/W) was changed from 1 to 8, and the slope angle was changed from 0° to 40°. Results indicate that the presence of a slope causes asymmetrical air entrainment on both sides of the fire plume, causing a pressure difference that leads to a decrease in the flame tilt angle as the slope angle increases. Additionally, the flame length increases monotonically with the slope angle due to the enhanced component of thermal buoyancy along the slope. Under the same slope condition, the flame tilt angle and flame height (perpendicular to the slope) decrease as the aspect ratio increases. This phenomenon is attributed to the increased entrainment restriction effect of the slope on the fire plume. New models for calculating flame tilt angle, flame length, and flame height, which consider the slope angle and aspect ratio of the fire source were established by using the equivalent perimeter of plume entrainment. To further verify the reliability of the newly established models, reference data with wide heat release rate (6.15 kW–231 kW), different slope inclination angle (0°–80°), pool size (equivalent diameter: 9 cm–44.1 cm), and different fuels (propane, ethylene) were used to against with the predicted values of our correlations. It is found that the maximum error of all correlations is within 15–20%, their universality and accuracy are further verified.

Ferroptosis contributes to cyclophosphamide-induced hemorrhagic cystitis

Cyclophosphamide (CYP) is extensively used in tumor therapy, but its clinical application is limited by its toxic effects on the bladder. Since CYP-induced cystitis is believed to be mediated by acrolein (ACR), a product of lipid peroxidation that triggers ferroptosis, we hypothesized that ferroptosis might be an essential molecular mechanism underlying CYP-induced cystitis. The purpose of this study was to test this hypothesis. Intraperitoneal injection of CYP led to bladder hemorrhage and edema, along with increased oxidation, inflammation, and cell injury. Further analysis revealed these changes were associated with altered ferroptosis markers in the bladder, such as FPN1, ACSL4, SLC7A11, and GPX4, indicating the existence of ferroptosis. Administration of ferroptosis inhibitor dexrazoxane (DXZ) improved ferroptosis and prevented CYP-induced pathological changes in the bladder. Collectively, our study revealed that ferroptosis is an important mechanism underlying CYP-induced cystitis, and therapeutic approaches targeting ferroptosis could be developed to treat CYP-induced cystitis.

A Dual Photoredox‐ and Cp2TiCl2‐Catalyzed Approach for the Direct Access to α‐Vinyl‐β‐hydroxy Esters

AbstractFor the first time, a dual photoredox‐ and titanocene‐catalyzed methodology for the regioselective access to α‐vinyl‐β‐hydroxy esters towards aldehyde allylation with 4‐bromobut‐2‐enoate is reported. The protocol is based on the Barbier‐type properties of the inexpensive and available Cp2TiCl2 in catalytic amount (5 mol%). The developed mild reaction conditions gave access to a library of differently functionalized α‐vinyl‐β‐hydroxy esters in moderate diastereoselectivity, employing the commercially available ethyl 4‐bromobut‐2‐enoate and both aromatic and aliphatic aldehydes. The reaction was realized under visible light irradiation, in the presence of an organophotocatalyst (3DPAFIPN, 2 mol%) combined with Hantzsch's ester as the sacrificial reductant. In contrast to other Barbier‐type reactions employing ethyl 4‐bromobut‐2‐enoate, the photoredox system ensures a better regioselectivity. Moreover, the use of preformed organometallic nucleophilic species (e. g., dienolborinates), and the need of metal reductants or stoichiometric amount of transition metals in low oxidation state for Barbier‐type reactions, is avoided. To support the experimental evidence, a detailed photophysical study shed light on the mechanism of the reaction.

Potential Threat Assessment and Degree of Exposure in the event of an Explosion by Sudden Expansion of Boiling Liquid Vapor in the LPG Ground Storage Terminal in Monteverde, coastal Ecuador

The industrial complexes that handle dangerous products with flammable characteristics have been the cause of great misfortunes when sudden explosions are generated, either due to mechanical failures or human negligence. The Monteverde Gas Complex (MGC), located in the province of Santa Elena in Ecuador, represents a potential risk by housing close to 105,000 m3 of precursor gases such as Propane (PPN), Butane (BTN), and LPG finished product. Therefore, an analysis of the potential threat to which the population is exposed in case of the explosion of one of the tanks with the different products they contain has been carried out, considering the closest communes to the MGC, which are Monteverde and Jambelí. Tools such as the Probit method proposed by TNO (The Netherlands Organization for Scientific Research), and the ALOHA software of the EPA (Environmental Protection Agency, USA) were used, whose combinations allowed estimating the radius of influence, which were divided into zones according to the degree of impact on the community. The results demonstrated that the community of Monteverde, despite being more than 1 km away from the CGM, is within the red zone or high influence radius that corresponds to 2000 meters for propane and butane tanks. Whitin this area, a person could have fatal third-degree burns. The calculations have been performed under ideal conditions, so it is recommended to review the attenuations generated by natural elevations of the terrain or the direction of the wind in further studies

Determination of the absorption function of laser-heated soot particles from spectrally resolved laser-induced incandescence signals using multiple excitation wavelengths

In this work, the optical properties of soot particles from a Gülder burner fueled with both ethylene or propane gas were investigated in situ using laser-induced incandescence. The particles in the flame were irradiated with four different laser wavelengths, namely 450 nm, 532 nm, 600 nm and 650 nm. The resulting laser-induced emissions were detected spectrally and temporally resolved by means of a spectrograph and an intensified camera at different delay times with respect to the laser pulse. To determine the optical properties of the particles from the data, the emitted spectra were simulated using a spectroscopic model with variable input parameters, and a regression was performed against the measured data. On the basis of an functional approach of the absorption function on wavelength, the dispersion exponent for soot was evaluated for a reference position on the centre axis at 40 mm height above the burner. It was found that the different fuel gases lead to similar values with regard to the absorption function, which can be expressed by a mean dispersion exponent with a value of 1.75 for ethylene and 1.68 for propane.

The Development of a Backup SOFC Generator at Upstart Power

Upstart Power is developing a state-of-the-art SOFC generator that provides backup power solutions for residential and industrial customers. The Upgen NXG™ fuel cell enables grid independence and pairs seamlessly with solar and/or standalone battery storage to provide extended backup power and 24/7/365 energy solutions. The system has dual fuel capability using either propane or natural gas and exports AC power via Enphase micro-inverters. Field trials are being conducted including a batch of 10 units in Puerto Rico running on propane in collaboration with Sunnova.The key technologies enabling the Upgen NXG™ system’s fast cycling and overall simplicity include:1) Integrated Hot Zone with advanced Thermal Management2) Custom dry CPOx reactor (waterless)3) Control strategy based on two thermocouple setpointsThe core of the NXG system is the Hot Zone which integrates the CPOx reactor, fuel cell stack, heat exchanger, flame sensor, spark ignitor and exhaust system. Figure 1 shows the complete subsystem layout of the NXG system, including the fuel filter, blowers, power electronics and controls. The core component of the Hot Zone is a single piece structure that comprises a thermally conductive element that conducts heat from the combustion chamber to the stack inlet. This enables both rapid start-up and enhanced performance from the stack, without the risk of cell failure due to thermal stress. Figure 2 shows a Hot Zone demonstrating 1000 rapid thermal/power cycles from operating temperature down to 200°C. The chart shows power per cycle with a heat-up time of 40 minutes. Power output was increased after 800 cycles with higher power test cycles run throughout the test.The dry CPOx reactor converts fuel gas into hydrogen and carbon monoxide for use in the fuel cell without the use of any additional water. The CPOx can operate at very low O:C ratios (< 1.2) providing stack fuel efficiencies up to 40% and is controlled by a single thermocouple in the reactor core. The other system control setpoint is the temperature in the core of the hot zone which provides a simple system control scheme with minimal yet reliable sensors.Figure 3 shows real time cycle data from the Upgen NXG™ system, with a start-up time of less than 60 minutes with 9 hours of steady state AC power exporting to the grid via Enphase micro-inverters. The cathode air flow is controlled by the thermocouple in the core of the Hot Zone (Radiated).In summary, the Upgen backup power systems outperform ICE generators and battery-only backup by providing unlimited backup solar + storage systems that are more robust, cost-effective and have lower emissions. The single wall mounted unit minimizes connections and simplifies installation over an ICE generator that typically sits on an outdoor concrete pad. With near silent operation and the absence of deadly CO emissions, the Upgen NXG™ is a safe and environmentally friendly backup power solution for residential solar and industrial customers. Figure 1

An Investigation of the Effect of Propylene Gas Flame on Emissions and Temperature Distribution of a Preheated Metal Plate

This study investigates the effect of the propylene gas flame on the emissions and temperature distribution of the metal plate during the preheating process. Experimental tests were carried out using a preheating system with a cylindrical chamber for emissions measurement and a metal plate placed near the torch head. Emissions were measured using a gas analyzer, while the temperature distribution of the metal plate was measured using an infrared thermal camera and thermocouples. The findings reveal that the emissions decrease as the equivalence ratio is increased as it approaches a ratio of 1. However, when the appropriate equivalence ratio is reached, NOx emissions will rise and then gradually fall. The peak temperature of propane fuel is higher than that of other fuels because of the concentrated flame. Propane fuel can achieve a peak temperature of 347.65 °C, surpassing both propylene fuel (275.45 °C) and acetylene fuel (335.45 °C). Using a propylene gas flame results in a reduction in emissions of carbon monoxide and nitrogen oxides compared to a propane flame. But, acetylene fuel produces the most NOx emissions, reaching 450.79 ppm for the experimental conditions. Additionally, the temperature distribution of the preheated metal plate was more uniform with the propylene gas flame, indicating improved heat transfer. However, the peak temperature of the metal plate was slightly lower when using the propylene gas flame.

Purification of Industrial Effluent by Gas Hydrate-based (HyPurif) Process

This study presents a sustainable HyPurif process for managing and recycling industrial water effluent, utilizing gas hydrate-based technology to purify complex effluent. This work purifies two effluents: one from a wastewater treatment plant (WWTP) and the other from a spent caustic treatment plant (SCTP). Various hydrate formers, including propane, HFC134a, and cyclopentane (6 mol %), were selected, as they typically form hydrates closer to ambient conditions. Hydrate formation experiments with effluent water were performed at 278.30 K using pure propane and HFC134a gas. Based on the kinetics of hydrate growth, the study was extended to a mixture (50:50%) of propane and HFC134a, operating at a pressure of 0.6 MPa. The mixture of propane and HFC134a has shown the desired result of forming the hydrate in the gas phase and having high separation efficiency. The results showed that the formation and dissociation of hydrates resulted in a separation efficiency of 80–95%. For instance, in the purified water, the biological oxygen demand (BOD) decreased from 2097 mg/L in the effluent sample to 220 mg/L in purified water (purification efficiency of 90.5%). The chemical oxygen demand (COD) decreased from 3100 mg/L in the effluent sample to 503 mg/L in purified water (purification efficiency of 84%). Total dissolved solids (TDS) were reduced from 89,632 mg/L in the effluent water to 14,698 mg/L in purified water (purification efficiency of 84%). Total suspended solids (TSS) were reduced from 35 mg/L in the effluent water to 3.5 mg/L in purified water (purification efficiency of 90%). However, the purification efficiency for free ammonia and residual chlorine was lower. The concentration of free ammonia decreased from 7 mg/L in the effluent sample to 1.89 mg/L in the purified water (purification efficiency of 73%), and residual chlorine reduced from 0.8 mg/L in the effluent sample to 0.2 mg/L in the purified water (purification efficiency of 75%). Water recovery of ≥40% was achievable per pass, which could be increased, but at the expense of purification efficiency. To the best of our knowledge, this is the first study on the purification of such complex wastewater containing organic and inorganic compounds, heavy metals, and various minerals using the HyPurif process.

Synephrine, as a scavenger and promoter, cooperates with hesperidin to reduce acrolein levels

Acrolein (ACR) is a harmful and active aldehyde produced in processed food that endangers foods safety. We undertook this work to explore the ACR-trapping ability of hesperidin (HES) and synephrine (SYN) from the diet. After comparing their ACR-trapping abilities, the reaction pathways of HES and SNY were analyzed using LC–MS/MS, and two adducts (HES-ACR-1 and SNY-2ACR) were synthesized, and their structures were identified by NMR. Then, we not only evaluated the synergistic trapping effects of HES and SNY on ACR in the model through the Chou-Talalay method but verified it in the processing of roasted duck wings and cookies. Furthermore, based on the quantitative analysis of the ACR-adducts of HES and SNY, we demonstrated that SYN, as a promoter, could greatly improve the ACR-capturing ability of HES by forming more adducts (3-fold). Our findings could serve as a guide for using SNY and HES as new scavengers in food processing.

GSM Based LPG Gas Leakage Detection &amp; Alert

To develop an efficient gas leakage detection system for vulnerable premises. The system utilizes a gas sensor with high sensitivity to propane (C3H8) and butane (C4H10) gases and incorporates a GSM module for sending warning SMS messages. This paper aims to present the design approach for both the software and hardware components of the system to ensure timely detection and prevention of gas leakage accidents.

Experimental Investigation of Acoustic Forcing on the Combustion Effect of Propane - Methane Mixtures

Today, the ever-increasing energy resource needs are of great importance for all countries in the global sense. Countries have recently been developing important policies to meet their energy needs and to use existing energy resources efficiently. In addition, in order to minimize the emissions that harm the nature as a result of the burning of energy sources, they have turned to alternative energy sources that are less harmful to the environment. In order to be an alternative energy source, in this study, the effect of enriching propane gas with methane gas on combustion in a Tubitak supported combustor was experimentally investigated. The enrichment of methane gas was determined at the rates of 10%, 20% and 30%, and the effects of acoustic stress on combustion, emission values and the effects on the flame were investigated. The thermal power was 7 kW and the equivalence ratio (Փ) was 1.2, and the experiment was carried out with a constant eddy value (1.0). When the experiment was carried out without acoustic stress, it was determined that the temperature, flame brightness and light intensity increased as the methane ratio increased, the dynamic pressure value almost did not change, the NOx value was negligibly small, and the CO value decreased depending on the oxygen amount as the methane ratio increased. In the experiments carried out under 90 Hz, 185 Hz and 330 Hz acoustic stress, as the forcing value increases, the temperature and flame brightness increase; It was observed that the NOx value was negligibly small, and the CO value decreased compared to the experiment performed without acoustic stress.

Contemporaneous and lagged [formula omitted] decomposed connectedness approach: New evidence from the energy futures market

In this study, we investigate the return propagation mechanism across six energy futures, namely, Crude Oil, Heating Oil, Gasoline, Natural Gas, Kerosene, and Propane ranging from November 21st, 2014 until April 6th, 2023 by using a novel R2 decomposed connectedness approach. This framework allows to efficiently decompose connectedness measures into contemporaneous and lagged components. We find that the dynamic total connectedness is heterogeneous over time and economic-event dependent. Furthermore, the empirical results highlight that the contemporaneous effects are more pronounced on average while a significant amount of lagged spillovers occur in the case of Kerosene and Propane. We find that Heating Oil is the main net transmitter of shocks followed by Gasoline and Crude Oil while the main net receiver of shocks is Kerosene followed by Propane and Natural Gas. Finally, robust R2 connectedness measures are provided.

Multiplex Surveillance Kit Using Sweetened Solid Support to Detect Arboviruses Isothermally in Mosquito Saliva from the Field.

Recently reported "displaceable probe" loop amplification (DP-LAMP) architecture has shown to amplify viral RNA from SARS-CoV-2 with little sample processing. The architecture allows signals indicating the presence of target nucleic acids to be spatially separated, and independent in sequence, from the complicated concatemer that LAMP processes create as part of their amplification process. This makes DP-LAMP an attractive molecular strategy to integrate with trap and sampling innovations to detect RNA from arboviruses carried by mosquitoes in the field. These innovations include (a) development of organically produced carbon dioxide with ethylene carbonate as a bait deployable in mosquito trap, avoiding the need for dry ice, propane tanks, or inorganic carbonates and (b) a process that induces mosquitoes to lay virus-infected saliva on a quaternary ammonium-functionalized paper (Q-paper) matrix, where (c) the matrix (i) inactivates the deposited viruses, (ii) releases their RNA, and (iii) captures viral RNA in a form that keeps it stable for days at ambient temperatures. We report this integration here, with a surprisingly simple workflow. DP-LAMP with a reverse transcriptase was found to amplify arboviral RNA directly from Q-paper, without requiring a separate elution step. This capture-amplification-detection architecture can be multiplexed, with the entire system integrated into a device that can support a campaign of surveillance, in the wild outdoors, that reports the prevalence of arboviruses from field-captured mosquitoes.

Experimental Examination of Recovery by a Thermoelectric Generator of Heat Energy Lost to Engine Coolant in a SI Engine

In this study, the recovery of heat energy lost to the engine coolant (Ec) in a liquid-cooled, gas-fueled (propane), spark ignition (SI) engine using a thermoelectric generator (TEG) is experimentally researched. A two-layer rectangular geometry TEG is designed, consisting of a propane heat exchanger (P_hex) located on the surface of an engine coolant heat exchanger (Ec_hex). 20 items of thermoelectric modules (TEMs), each 30x30 mm in dimensions, are placed between the Ec_hex and P_hex. In the TEG design, engine cooling fluid is used on the hot surface of the TEMs, and propane gas fed to the engine is used on the cold surface. In addition, with the use of the designed TEG, there is no need to use an additional evaporator for propane gas. Experiments are carried out with the designed TEG at 8 engine speeds ranging from 1500 to 5000 rpm. As a result, TEG produces 1.25–3.01 W of DC electrical power in the engine's 1500–5000 rpm range, while TEG efficiency fluctuates between 2.7 and 3.1%. However, the maximum TEG_power is 3.01 W at 5000 rpm, while the maximum TEG_efficiency is 3.1% at 1500 rpm. On the other hand, the electrical power of TEG between 1500 – 5000 rpm of the engine is approximately 1.1–1.26% of the engine charging system power. However, TEG's contribution to the charging system again decreases with the engine speed.

Difunctionalization of 1,3-Butadiene via Sequential Radical Thiol-ene Reaction and Allylation by Dual Photoredox and Titanium Catalysis.

Recently, radical difunctionalization of the feedstock 1,3-butadiene has become an attractive strategy for increasing molecular complexity. Herein, we present a novel approach that effectively combines radical thiol-ene chemistry with TiIII catalysis to enable a three-component aldehyde allylation using 1,3-butadiene as an allyl group source under visible light conditions. This sustainable and straightforward method has facilitated the rapid production of diverse allylic 1,3-thioalcohols with exceptional regio- and diastereoselectivity.

Ultralight FeSiAl micro-flake flying with propylene to favor fast growth of carbon nanotube arrays at 99 % high-efficient conversion

The efficiency of catalyst-gas contact and the selectivity of catalyzing carbon source cracking determine the yield of highly oriented carbon nanotube arrays (CNTAs). Herein, the flying FeSiAl (FSA) micro sheets were in full contact with propylene (C3H6), effectively catalyzing propylene gas cracking with an astonishing 99 % carbon conversion rate. The propylene with more carbon atoms and high safety grew carbon nanotube arrays faster. The growth kinetics of the CNTAs were studied, and the apparent activation energy of the CNTAs was 49.04 kJ/mol. This indicated that there were two diffusion modes: the surface diffusion of the catalyst and the step-edge diffusion of the graphene-catalyst interface. The well-dispersed linear CNTAs (1D) and a point-like carbon black (0D) conductive agent form a 1D/0D conductive network, which was used as a conductive additive for lithium/fluorocarbon (CFx) primary cells. Effective electron conduction improved the rate performance of the battery, which was increased from 1229.22 Wh/kg at 2 C to 1358.35 Wh/kg at 4 C. The high catalytic efficiency of propylene molecules with high carbon content and FeSiAl (FSA) alloy provides a new method for large-scale and efficient production of CNTAs. High-orientation CNTAs have potential application prospects in the field of energy storage.