High Gas Flow Rates Research Articles

EFFECT OF NITROGEN DOPING ON FRICTION AND WEAR PROPERTIES OF THICK TETRAHEDRAL AMORPHOUS CARBON COATING

In the present study, the coating was deposited by the filtered cathode vacuum arc (FCVA) plasma technique, and the effect of the nitrogen gas doping on the friction and wear performances of the thick layer of nitrogen-doped tetrahedral amorphous carbon (ta-C:N) coating were investigated. The tribological behavior of the coating was investigated by sliding an SUJ2 ball over the coating in a ball-on-disk tribo-meter. The experimental results revealed that doping using a high nitrogen gas flow rate improved the wear resistance of the coating, while a low flow rate of 0–10 sccm increased the coefficient of friction (CoF) and wear rate dramatically decreased when the nitrogen flow rate was increased to 30–40 sccm. This was due to the nitrogen-induced phase transformation, resulting in the production of a graphite-like structure in the interface between disk and SUJ2 ball. The widths of the wear track and wear scar were also observed to decrease with increasing nitrogen flow rate. Moreover, the G-peaks of the wear scar around the SUJ2 ball on the worn surface increased with increasing nitrogen doping.

Numerical Modeling of Open-Eye Formation and Mixing Time in Argon Stirred Industrial Ladle

In secondary metallurgy, argon gas stirring and alloying of elements are very important in determining the quality of steel. Argon gas is injected through the nozzle located at the bottom of the ladle into the molten steel bath; this gas breaks up into gas bubbles, rising upwards and breaking the slag layer at high gas flow rates, creating an open-eye. Alloy elements are added to the molten steel through the open-eye to attain the desired steel composition. In this work, experiments were conducted to investigate the effect of argon gas flow rate on the open-eye size and mixing time. An Eulerian volume of fluid (VOF) approach was employed to simulate the argon/steel/slag interface in the ladle, while a species transport model was used to calculate the mixing time of the nickel alloy. The simulation results showed that the time-averaged value of the open-eye area changed from 0.66 to 2.36 m2 when the flow rate of argon was varied from 100 to 500 NL/min. The mixing time (95% criterion) of tracer addition into the metal bath decreased from 139 s to 96 s, when the argon flow rate was increased from 100 to 500 NL/min. The model validation was verified by comparing with measured experimental results.

Thermal Plasma Synthesis of Zirconia Powder and Preparation of Premixed Ca-Doped Zirconia

A novel study about the synthesis of zirconia and calcia-stabilized zirconia powders were carried out by DC thermal plasma starting from cheap precursors as the carbonates. Different operational parameters were investigated to explore the effects of the process conditions, such as the plasma torch power and the gas flow rate on the composition and the morphology of the powders. The products phase changes from a metastable tetragonal to monoclinic/tetragonal mixture. Basically a main tetragonal phase was obtained at low torch power (7 kW) while the amount of monoclinic phase linearly rises with the power, up to 66 wt% at 26 kW of plasma power and high gas flow rate. The gas flow rate also affects the shape and the size of the powder, where high values reduce powder aggregation and enhance the spherical shape. The best results were achieved at 22 kW of plasma power and high gas flow rate, with powders of roundness about 79% and a wide particle size distribution. Adding the calcium carbonate to the zirconium carbonate (corresponding to 8 wt% CaO in the final mixture), the plasma treatment mainly produces a tetragonal phase zirconia, that at 1400 °C in furnace changes in a stable cubic phase. These powders could be made suitable for further industrial applications after proper treatments.

Modeling and Simulation of the Absorption of CO2 and NO2 from a Gas Mixture in a Membrane Contactor

The removal of undesirable compounds such as CO2 and NO2 from incineration and natural gas is essential because of their harmful influence on the atmosphere and on the reduction of natural gas heating value. The use of membrane contactor for the capture of the post-combustion NO2 and CO2 had been widely considered in the past decades. In this study, membrane contactor was used for the simultaneous absorption of CO2 and NO2 from a mixture of gas (5% CO2, 300 ppm NO2, balance N2) with aqueous sodium hydroxide solution. For the first time, a mathematical model was established for the simultaneous removal of the two undesired gas solutes (CO2, NO2) from flue gas using membrane contactor. The model considers the reaction rate, and radial and axial diffusion of both compounds. The model was verified and validated with experimental data and found to be in good agreement. The model was used to examine the effect of the flow rate of liquid, gas, and inlet solute mole fraction on the percent removal and molar flux of both impurity species. The results revealed that the effect of the liquid flow rate improves the percent removal of both compounds. A high inlet gas flow rate decreases the percent removal. It was possible to obtain the complete removal of both undesired compounds. The model was confirmed to be a dependable tool for the optimization of such process, and for similar systems.

Numerical Investigation of In-Flight Behavior of Fe-Based Amorphous Alloy Particles in AC-HVAF Thermal Spray Process

Computational fluid dynamics is used to investigate the in-flight behavior of particles of Fe-based amorphous alloy powder in an activated combustion high-velocity air fuel spray process. The continuity, momentum, energy, and species equations are solved with a renormalization group k–e turbulence model to predict the flow fields. A one-step chemistry model and eddy-dissipation model are used to simulate the combustion reaction. The processing of the Fe-based amorphous alloy particles in the gas flow is modeled based on the Lagrangian approach. The predictions show that the static pressure and flame temperature of the combustion products in the combustion chamber can reach up to 515,000 Pa and 1600 K, respectively, under the conditions considered in this study. Both the temperature and velocity of the alloy particles are strongly affected by the powder particle size. The particle injection position also has a great influence on the particle temperature. The greater the deviation of the injection point from the centerline, the higher the particle temperatures. The nitrogen flow rate and particle size were projected as two important parameters to avoid nozzle clogging, revealing that high gas flow rates and large particles favor expansion of the particle stream in the radial section during the spray process.

Supersonic separator for cleaner offshore processing of supercritical fluid with ultra-high carbon dioxide content: Economic and environmental evaluation

Offshore gas processing presents challenges, especially when high flow rates, high-pressure and high carbon dioxide contents are involved. The present scenario comprehends offshore processing of high flow rate of high-pressure natural gas with 68%mol carbon dioxide, which results from oil production and behaves as a dense supercritical fluid. The processing goals with this fluid comprise: [A] water dew-point adjustment; [B] hydrocarbon dew-point adjustment; [C] decarbonation of a small part to 20%mol carbon dioxide fuel-gas for power production; and [D] compression/pumping of the remaining fluid enriched with carbon dioxide from decarbonation for enhanced oil recovery. For these tasks the industry considers traditional well established processes such as molecular-sieves adsorption for water dew-point adjustment, Joule-Thompson expansion for hydrocarbon dew-point adjustment and membrane-permeation for carbon dioxide removal. However, conventional technologies can become cumbersome in such awkward conditions. Thus, unconventional solutions are sought for reliability, lower equipment size/weight, and better power consumption, emissions and environmental sustainability. Recently, supersonic separators have been analyzed in proof-of-concept researches for natural gas processing. In this regard, this work quantitatively proves that goals [A],[B],[C] are achievable using only supersonic separators, attaining 33% higher net value, 40% greater oil production, 10% lower investment and economic leverage to reach lower carbon emission relatively to conventional counterparts.

Influence of the position of charcoal air-filtration canisters on the efficacy of waste isoflurane scavenging as assessed in a randomized experiment.

OBJECTIVE To determine whether the position or elevation of charcoal air-filtration canisters would impact efficacy of waste anesthetic gas (WAG) scavenging. DESIGN Randomized experiment. SAMPLE 2 types of bottom-vented and 1 type of top-vented charcoal air-filtration canisters (n = 8 of each canister type/evaluation session). PROCEDURES Canisters were evaluated in a vertical or horizontal position at both low and high isoflurane gas flow rates in a modified Bain nonrebreathing circuit. Waste anesthetic gas concentrations were measured 2.54 cm from canister exhaust ports with an ambient air analyzer every 30 seconds for a maximum of 15 min/experimental condition. One type of bottom-vented canister was tested in a vertical position elevated above or suspended below the vaporizer at a high isoflurane flow rate and then a standard maintenance flow rate. RESULTS Position had no significant effect on WAG emission by any canister type at low isoflurane flow rates. Horizontally positioned bottom-vented canisters at the high isoflurane flow rate emitted significantly more WAG than vertically positioned canisters. Horizontally positioned top-vented canisters at high flow rates emitted significantly more WAG than vertically positioned canisters at the final 15-minute time point only. Cannister types differed significantly in intercanister variability. Canister elevation relative to the vaporizer had no impact on WAG scavenging efficacy. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that charcoal air-filtration canisters should be used in a vertical position when anesthetizing animals with the anesthetic delivery system used in this study.

On the effect of using collision/reaction cell (CRC) technology in single-particle ICP-mass spectrometry (SP-ICP-MS)

In this work, the effects of using collision/reaction cell (CRC) technology in quadrupole-based ICP-MS (ICP-QMS) instrumentation operated in single-particle (SP) mode have been assessed. The influence of (i) various CRC gases, (ii) gas flow rates, (iii) nanoparticle (NP) sizes and (iv) NP types was evaluated using Ag, Au and Pt NPs with both a traditional ICP-QMS instrument and a tandem ICP-mass spectrometer. It has been shown that using CRC technology brings about a significant increase in the NP signal peak width (from 0.5 up to 6 ms). This effect is more prominent for a heavier gas (e.g., NH3) than for a lighter one (e.g., H2 or He). At a higher gas flow rate and/or for larger particle sizes >100 nm), the NP signal duration was prolonged to a larger extent. This effect of using CRC technology has been further demonstrated by characterizing custom-made 50 and 200 nm Fe3O4 NPs (originally strongly affected by the occurrence of spectral overlap) using different CRC approaches (H2 on-mass and NH3 mass-shift). The use of NH3 (monitoring of Fe as the Fe(NH3)2+ reaction product ion at m/z = 90 amu) induces a significant peak broadening compared to that observed when using H2 (6.10 ± 1.60 vs. 0.94 ± 0.49 ms). This extension of transit time can most likely be attributed to the collisions/interactions of the ion cloud generated by a single NP event with the CRC gas and it even precludes 50 nm Fe3O4 NPs to be detected when using the NH3 mass-shift approach. Based on these results, the influence of a longer peak width on the accuracy of SP-ICP-MS measurement data (NP size, particle number density and mass concentration) must be taken into account when using CRC technology as a means to overcome spectral overlap. To mitigate the potential detrimental effect of using CRC technology in the characterization of NPs via SP-ICP-MS(/MS), the use of light gases and low gas flow rates is recommended.

Exploration of Mn incorporated CeO2 nanoflakes with meso- and macropores for the effective simultaneous catalytic oxidation of carbon monoxide and propane

Highly porous ceria nanoflakes are prepared by a facile citric acid assisted sol–gel method. A Mn incorporated solid solution of CeO2 was also efficiently developed without disturbing the nanoflake morphology of pure CeO2. The formation of fluorite CeO2 with crystallite size ranging from 5–8 nm is evidently revealed from XRD analysis. The introduction of Mn to CeO2 resulted in the formation of smaller crystallites of CeO2 with reduced particle size and lattice parameters. SEM images displayed the flake like nature of CeO2 and Mn/CeO2 with meso and macro pores. TEM images confirm the pore size reduction of CeO2 with Mn doping which is already indicated from BET-BJH-surface area and pore-volume analysis. The presence of a large amount of oxygen vacancies in CeO2 upon Mn introduction is indicated from the drastic reduction in the peak intensities in the Raman spectrum. XPS results revealed that Ce exists in its +4 oxidation state whereas Mn exists in its +3 oxidation state, both of which are favorable for oxidation reactions. The catalytic performance of the prepared nanoflakes is investigated in the simultaneous oxidation of CO and C3H8. Mn incorporated CeO2 showed 100% oxidation of CO from 300 °C onwards and 84% hydrocarbon oxidation is observed even at a high gas flow rate of 500 ml/min at 400 °C over 0.5 g of the catalyst.

Study on Nanofibrous Catalysts Prepared by Electrospinning for Methane Partial Oxidation

Electrospinning is a simple and efficient technique for fabricating fibrous catalysts. The effects of preparation parameters on catalyst performance were investigated on fibrous Ni/Al2O3 catalysts. The catalyst prepared with H2O/C2H5OH solvent showed higher catalytic activity than that with DMF/C2H5OH solvent because of the presence of NiO in the catalyst prepared with DMF/C2H5OH solvent. The metal ion content of the precursor also influences catalyst properties. In this work, the Ni/Al2O3 catalyst prepared with a solution containing the metal ion content of 30 wt % demonstrated the highest Ni dispersion and therefore the highest catalytic performance. Additionally, the Ni dispersion decreased as calcination temperature was enhanced from 700 to 900 °C due to the increased Ni particle sizes, which also caused a high reduction temperature and low catalytic activity in methane partial oxidation. Finally, the fibrous Ni/Al2O3 catalysts can achieve high syngas yields at high reaction temperatures and high gas flow rates.

Experimental study on transient flow fluctuation characteristics in a 3 × 3 rod bundle under rolling condition

Abstract Experimental investigation on adiabatic transient flow fluctuation characteristics in a 3 × 3 rod bundles subjected to rolling motion in normal pressure and temperature was carried out. Single-phase flow as well as gas parameters under stagnant liquid condition were concerned. Ranges of liquid Reynolds number and gas flow rate were 657–3 328 and 0.079–0.2 m3/h, respectively. Rolling period and amplitude range from 8 s to 16 s and from 5° to 15°, respectively. Fluctuation amplitudes of transient parameters such as flow rate, pressure drop, void fraction and gas rising velocity were focused on this study. The results indicate that flow rate and frictional pressure drop present obvious fluctuations after rolling motion, and the fluctuation amplitudes decrease with the decrease of bypass valve opening. Flow rate reaches to peak at the positive rolling amplitude and it reaches to trough at the negative rolling amplitude, and there is no obvious phase difference between the fluctuation and rolling angle. Periodical fluctuation of gas flow rate was weakened with the increase of gas inlet pressure and valve opening under experimental conditions, while the variations of void fraction and gas rising velocity were limited. Transient parameter fluctuations correspond to the rolling period at low gas flow rate, whereas their periodical fluctuations are inconspicuous in relative high gas flow rate. Amplitudes of void fraction and gas rising velocity increase with increasing the rolling amplitude while the amplitudes of void fraction and gas rising velocity are nearly invariable with the rolling period no matter if gas flow rate oscillates.

Power-to-methane via co-electrolysis of H2O and CO2: The effects of pressurized operation and internal methanation

This paper presents a model-based investigation to handle the fundamental issues for the design of co-electrolysis based power-to-methane at the levels of both the stack and system: the role of CO2 in co-electrolysis, the benefits of employing pressurized stack operation and the conditions of promoting internal methanation. Results show that the electrochemical reaction of co-electrolysis is dominated by H2O splitting while CO2 is converted via reverse water-gas shift reaction. Increasing CO2 feed fraction mainly enlarges the concentration and cathode-activation overpotentials. Internal methanation in the stack can be effectively promoted by pressurized operation under high reactant utilization with low current density and large stack cooling. For the operation of a single stack, methane fraction of dry gas at the cathode outlet can reach as high as 30 vol.% (at 30 bar and high flowrate of sweep gas), which is, unfortunately, not preferred for enhancing system efficiency due to the penalty from the pressurization of sweep gas. The number drops down to 15 vol.% (at 15 bar) to achieve the highest system efficiency (at 0.27 A/cm2). The internal methanation can serve as an effective internal heat source to maintain stack temperature (thus enhancing electrochemistry), particularly at a small current density. This enables the co-electrolysis based power-to-methane to achieve higher efficiency than the steam-electrolysis based (90% vs 86% on higher heating value, or 83% vs 79% on lower heating value without heat and converter losses).

Nasal High-Flow Nebulization for Lung Drug Delivery: Theoretical, Experimental, and Clinical Application

The use of nasal high-flow (NHF) therapy is rapidly spreading across acute care facilities. This raises the question of optimal delivery of inhaled medication to patients undergoing this noninvasive ventilatory support consisting in delivering heated and humidified high gas flow rates through nasal cannulas. In this article, we review experimental and clinical work evaluating the delivery of inhaled medication within the NHF circuit to target the lung without interrupting the ventilatory support. Using vibrating mesh nebulizers placed immediately upstream or downstream of the humidification chamber, with flow rates of 30-45 L/min in adults and 2-6 L/min in children and infants, about 1%-10% of the drug charged in the nebulizer may be delivered to the lungs. Compared with conventional facemask aerosol interfaces, this amount is significantly lower than amounts delivered to adults (i.e., up to 25% of the nominal dose), but similar to amounts delivered to children and infants, the latter having a predominantly nasal breathing. However, significant clinical effects have been shown in both populations when delivering bronchodilators through NHF. This interface is particularly well tolerated and may be useful to improve aerosol therapy tolerance in the pediatric setting. Thus, among patients undergoing NHF therapy, bronchodilators may be delivered through this route. Whereas other drugs may be delivered this way or if there is a patient-centered benefit to specifically use NHF for aerosol therapy among patients without ongoing ventilatory support, requires further evaluation and technological development.

Carbon capture and high-capacity supercritical fluid processing with supersonic separator: Natural gas with ultra-high CO2 content

Some deep-water offshore fields produce oil with high gas/oil ratios and ultra-high %CO2 (>60%mol) with the onus of processing low-grade gas simultaneously handling huge CO2 dispatch goals. Thus, processing solutions are needed to make feasible such high-capacity gas rigs hundreds of kilometers offshore. Feasibility relies on the choices for CO2 capture and adjustment of water and hydrocarbon dew-points of such high flow rate gas. This problem was approached adopting supersonic separators for dew-point adjustments and for CO2 capture on a floating-hub processing 50 MMsm³/d of CO2 ultra-rich gas, reinjecting 96% of treated CO2-rich gas for enhanced oil recovery, while reserving 4% as fuel-gas after CO2 abatement to 20%mol for power production. Process alternatives were assessed in terms of power demand and profitability comparing supersonic separator with membrane-permeation for CO2 removal. Results show that 1st supersonic separator for dew-point adjustments of raw gas recycling condensate to the oil-gas-water separator and 2nd supersonic separator for CO2 removal avoiding CO2 freeze-out, give optimum net present value and minimum CO2 emissions. On one hand, these facts are consequences of less compressor investment as 2nd supersonic separator ejects pressurized CO2 condensate requiring 5% less compression power for enhanced oil recovery relatively to the power required by the low-pressure CO2-rich permeate from the membrane-permeation alternative. On the other hand, the best net value of supersonic separator alternative also reflects its highest revenues derived from recycling condensate from 1st supersonic separator entailing 18% higher oil production.

An outlook towards 2030: Optimization and design of a CCUS supply chain in Germany

A mathematical model for the optimal design of a supply chain for carbon capture, utilization and storage is developed. Carbon dioxide may be stored and/or utilized to produce methanol via methane dry reforming. The Mixed Integer Linear Program model is developed for ten major carbon dioxide emission sources in Germany. Three different cases are considered, according to hydrogen production route required to correct the syngas composition: hydrogen by external reforming, hydrogen by external water electrolysis, hydrogen by internal steam reforming. Results show that absorption is the preferred capture solutions at high flue gas flow rate. Results also show that the best option is providing hydrogen by water electrolysis, because a higher amount of carbon dioxide is used to produce the same amount of methanol with lower environmental impact. The proposed network produces 203 Mton/year of methanol, then Germany would be able to satisfy the world methanol demand in the next years. Carbon tax and economic incentives are required to reduce the methanol production cost to 340 €/ton: only in this case the process is economically feasible.

Effect of pH and Gas Flow Rate on Ozone Mass Transfer of Κ-Carrageenan Solution in Bubble Column Reactor

This research was conducted to calculate the mass transfer coefficient value for ozonation reaction of κ-carrageenan solution in the bubble column reactor. Ozone gas was produced using ozone generator type corona discharge. In this study, operating conditions were regulated at ozone gas flow rate 2- 5 L min-1, pH 4-10, and temperature 29 ± 1 oC. Samples were tested every 5 minutes to determine the dissolved ozone concentration. The results showed that dissolved ozone concentrations increased with increasing ozonation time and ozone gas flow rate. However, a very high gas flow rate can increase turbulence so that the mass transfer coefficient (kLa) value decreased. In alkaline conditions, the formation of free radicals (HO*) increases so that the amount of dissolved ozone decreases. The kLa value of ozone gas in κ-carrageenan solution is slightly lower than the kLa value of the ozone gas in the water. The results of this study indicate that (kLa) ozone gas in water is 0.131 / minute while the value (kLa) in κ-carrageenan solution is 0.128 / minute.Keywords: ozone; mass transfer; pH; flowrate

Effect of gas distributor on gas–liquid dispersion and mass transfer characteristics in stirred tank

Aiming at the fact that the function of gas distributor is often neglected in the case of high viscosity conditions, a novel spherical micro-orifice gas distributor was proposed and investigated experimentally in water system and non-Newtonian viscous system, respectively. The comparisons of gas–liquid dispersion and mass transfer performance between novel spherical micro-orifice gas distributor and traditional ring distributor were also done. Furthermore, the effects of gas distributors on the gas–liquid dispersion and mass transfer characteristics of three wide-viscosity-range impellers including LDB impeller, FZ impeller and MB impeller were also researched, and an impeller-distributor configuration with good gas–liquid dispersion and mass transfer performance was achieved. The results show that, compared with ring gas distributor, the bubbles dispersed by novel spherical micro-orifice gas distributor are smaller, and the gas holdup and volumetric mass transfer coefficient are relatively higher under the same power consumption per unit volume. Meanwhile, the significant effect of gas distributor geometry on gas dispersion was found for high-viscosity liquid, but not relevant for low-viscosity batches. In addition, compared with other impeller-distributor configurations, the configuration consisting of FZ impeller and novel spherical micro-orifice gas distributor can achieve greater global gas holdup and higher oxygen mass transfer rate, which is recommended especially in viscous system with high gas flow rate. The research is beneficial to promote the application of novel spherical micro-orifice gas distributor in stirred tanks.

Experimental and theoretical investigation on pool entrainment under small air flow rate

The liquid entrainment is a ubiquitous phenomenon in nuclear engineering. In the scenario of SBLOCA, liquid entrainment plays an important role threatening the core safety. Numerous research has been conducted on the mechanism of pool entrainment. Part of experiment data could be predicted well by Kataoka-Ishii entrainment correlation which has been widely used. However, most research focused on the pool entrainment is conducted under intermediate or high gas flow rate. The Kataoka-Ishii correlation is also less accurate when air flow rate is small. Therefore, an experimental investigation under small air flow rate is important to conduct. This paper demonstrates experiment apparatus, instrumentation, experiment phenomenon as well as relevant analysis. An entrainment correlation is proposed based on the experiment data. The relative uncertainty of fitting entrainment correlation based on the experiment data is within ±30%. Entrainment factor influenced by exit effect of different location is specifically deducted. The transition region of pool entrainment is analyzed and can be estimated by flow pattern map. Some typical entrainment patterns under different air flow rate are also illustrated and described.

Effects of Nozzle Radial Position, Separation Angle, and Gas Flow Partitioning on the Mixing, Eye Area, and Wall Shear Stress in Ladles Fitted with Dual Plugs

Mixing time, slag eye area, and wall shear stress in a ladle fitted with dual plugs have been studied as a function of operating variables, namely, gas flow rate, radial nozzle position, separation angle between nozzles and flow rate partitioning. While the mixing time and slag eye area have been experimentally investigated in a scaled water model (with and without a top slag layer), the shear stress on the vessel wall has been studied computationally via a RANS-based turbulent, three-dimensional coupled Eulerian–Lagrangian (VOF-DPM), multiphase flow model. Experimental and computational results have indicated that the mixing, eye area, and wall shear stress depend on the gas flow rate, i.e., while mixing efficiency increases with the increasing gas flow rate, the slag eye area, and wall shear stress, in contrast, become more pronounced with the increasing gas flow, leading to an undesirable operating regime. The radial nozzle position, separation angle between the nozzles and flow rate partitioning at any given flow rate also influence the ladle process performance, influencing the mixing, eye area, and wall shear stress, albeit to a varied degree. Within the range of operating conditions studied, an expected inverse correspondence between mixing time and shear behavior was observed. Experimental and computational results in conjunction have indicated that the best arrangement of porous plugs or gas injection nozzles for superior ladle process performance is dependent on the gas flow rate and is specific to the desired objective (i.e., decreasing the mixing time, or slag eye area and wall shear stress). Hence, a unique gas injection practice cannot and should not be suggested as the optimum for ladle metallurgy in steelmaking. Nevertheless, if the mixing time is the parameter of primary interest, a nozzle configuration with equal flow partitioning (1:1) between the nozzles and identical nozzle radial positions (0.7R/0.7R, 45 deg) should suffice for both low and high gas flow rates. In contrast, a nonidentical nozzle radial position (0.7R/0.5R, 90 deg) and an unequal gas flow rate per nozzle (1:3) appear preferable if both ladle eye and shear stresses, rather than mixing, are the issues of concern.

Combined with fractional condensation to upgrade the liquid products derived from the co-pyrolysis of bio-oil distillation residue and bituminous coal

In this study, the effects of induction conditions on the distribution characteristics of graded bio-oil derived from the co-pyrolysis of bio-oil distillation residue and bituminous coal were investigated in a fixed pyrolysis reactor with a three-stage condenser. Based on the central composite design and statistical analysis, it could be found that a quadratic model was recommended to depict the total bio-oil yield, whereas the linear model was the best-fitting model for the graded bio-oil yield of different condensation stages. As for total bio-oil yield, all the combined effects of induction conditions played a negative role, and all second-order effects were advantageous. Moreover, the high percentage of distillation residue contributed to the bio-oil yield at each condenser and had the greatest impact on the bio-oil yield of the first condenser. However, high temperatures and high gas flow rates reduced the bio-oil yield of the first condenser and favored the increase in bio-oil yield of subsequent condensers. In addition, the products derived from distillation residue were more abundant than bituminous coal. And the addition of bituminous coal did not significantly increase the type of compounds in bio-oil from the blends, but disturbed the distribution of bio-oil products. The condensers with different temperatures facilitated the separation and enrichment of different compounds.