N2 Flow Rate Research Articles

Utilization of Sewage Sludge Using Multiple Thermal Conversion Processes

Sewage sludge is a usual waste from urban areas that can be utilized in many renewable energy sources. In this study, we examine the sewage sludge utilization using pyrolysis process to produce pyrolytic oil using Taguchi methods, combustion characteristic of sludge pyrolytic oil (SPO) blend with heavy fuel oil (HFO), and co-gasification of sewage sludge with CO2/steam as the gasification medium using Taguchi methods. The best-operating conditions for the pyrolysis of sewage sludge are a heating rate of 10oC/min, temperature of 450oC, the residence time of 60 min, and N2 flow rate of 700 mL/min. Under these conditions, the obtained pyrolytic oil yield is very close to the result from the Taguchi method calculation. In the combustion characteristic of sludge pyrolytic oil (SPO) blend with heavy fuel oil (HFO), a higher SPO in the fuel blend enhances the occurrence of micro-explosion and reduces the size of the residual. Higher SPO content in the fuel blend increases the combustion rate and increases the ignition delay due to moisture evaporation. In the co-gasification of sewage sludge and palm kernel shell optimization using Taguchi method, the best operational condition for maximum H2/ CO syngas ratio reaches at the gasification temperature of 900 C, a blending ratio of 30%, a CO2/(CO2+H2O) ratio of 70%, and a catalyst addition of 20% bed material mass. The best operating condition for maximum concentration of H2 reach with gasification temperature of 800 C, a blending ratio of 40%, a CO2/(CO2+H2O) ratio of 70%, and a 15% catalyst addition of bed material mass. The CO2/(CO2+H2O) ratio is the most important parameter among both case.

Study on the influence of residence time on the componential evolution of biomass pyrolysis vapors during indirect heat exchange process through a combining method of bio-oil composition inversion and function fitting

A novel and effective experimental method for describing the evolution curves and hot maps of biomass pyrolysis vapors with the adjustment of sweeping gas flow rate was developed during condensation. The composition proportion of pyrolysis vapors was inverted from the composition quantification of segmental bio-oil recovered by the specific condenser with two flumes. The mathematical relationship between location and vapor composition was fitted by Slogistic function. The condensable proportion of water decreased from 85% to 60% as N2 flow rate increased from 100 mL/min to 500 mL/min under 340 K water bath. But 500 mL/min N2 flow rate accelerated the disturbance of condensing field and improved the recoveries of components with stronger condensing abilities than water. The condensable proportion of guaiacol and its derivatives decreased from 60% to 40% under 300 mL/min but increased to 55% under 500 mL/min. Furthermore, the evolution difference between high-proportion and low-proportion components in pyrolysis vapors in the condensing field was also discussed as well as the unique evolution of components with azeotrope phenomenon or special solubility. For the first time, the adjustment mechanism of constant non-condensable components on the evolution of condensable components was clarified during water bath condensation, which would remarkably improve the comprehension for the complex phase transition process during the selective condensation of biomass pyrolysis vapors.

Transparent conductive properties of TiON thin films

Titanium oxynitride (TiON) thin films were deposited on glass substrates by reactive sputtering of a Ti target under a flow of O2 and N2 gases. When the total number of O and N atoms bonded to Ti was small, the TiON films took on a nano-crystalline fcc structure primarily oriented toward the (200) direction. As the TiON films became more oxidized and/or nitrided, they gradually transformed into an amorphous state with their carrier concentration being between 1018 and 1019 cm−3. The efficiency of oxidization was six times higher than that of nitridation. The optical transmittance of TiON films deposited at RT under sufficient O2 and N2 flow rates reached 100% at wavelengths longer than 1000 nm. However, complete termination of Ti with N atoms failed to occur at low O2 flow rates even when the N2 flow rate was increased. The carrier concentration (n) of the TiON films could be varied in a wide range between 1018 and 3 × 1021 cm−3. The n (×10−19 cm−3) versus Hall mobility (μ) (cm2 V−1 s−1) plot scaled as log μ = 1.23 − 0.38⋅log n between 1 × 1018 and 1 × 1020 cm−3. The Hall mobility reached 20–50 cm2 V−1 s−1 at n = 1018 cm−3, which means this film is promising as an amorphous semiconductor. The log–log plot of resistivity (ρ) (mΩ cm) against n scaled as log ρ = 1.74 − 0.87⋅log n.

Dissolved carbon dioxide stripping while maintaining volatile components by feeding gaseous nitrogen using a microbubble generator.

Dissolved carbon dioxide (dCO2) stripping from a model solution containing sake flavor by feeding gaseous nitrogen (N2) using a microbubble (MB) generator was investigated. The effect of dCO2 stripping by N2MB increased significantly with increasing flow rate of gaseous N2 from 100 to 200mL/min. dCO2 stripping from 3,000mL of the model solution was achieved by feeding N2MB at a flow rate of 200mL/min for 4min. Volatile components from model solution containing sake flavor were hardly reduced even after feeding N2MB at a flow rate of 200mL/min for 15min by cooling to below 10 °C. On the other hand, non-microbubbled gaseous N2 at a flow rate of 200mL/min was not very effective in stripping dCO2. Therefore, the use of N2MB with cooling to below 10 °C was effective in stripping dCO2 while maintaining the volatile components in model solution containing sake flavor.

Evaluation of Chemical Bonding States in Multilayer Interconnect Structures for Thermal Management in Next Generation Very Large Scale Integration

1. Background and purpose Currently, it is expected that Ru is going to be introduced in place of Cu, which is the mainstream interconnect material in the very large scale integrated (VLSI) circuit. As high integration has been proceeding, the interconnect is expected not only having excellent electrical characteristics and reliability, but also providing an effective pathway for the removal of the heat generated by device operation [1]. The increasing current density in the narrowing interconnect produces Joule heat. The generated heat is removed by a heat sink attached to the substrate through the interconnect. Therefore, if the thermal resistance between the substrate and the interconnect is high, the heat cannot be removed efficiently and the interconnect temperature rises, lead to a degradation of VLSI reliability [2].In this study, we evaluated chemical bonding states of Ru/TaN/(SiOx/)Si stacking structure to clarify the mechanism contributing thermal resistance for the superior thermal management in VLSI. 2. Experimental method A 5 nm TaN was deposited by reactive sputtering (Deposition conditions: 25°C, 300 W, 1.0×10-5 Pa, Ta target) and subsequently 10 nm Ru was deposited by magnetron sputtering on a Si substrate with approximately 2 nm-thick native oxide. We prepared four samples with Ar:N2 gas ratios of 19:1, 17:3, 16:4, and 15:5, respectively, during the TaN deposition. The total thermal resistance was measured by the Frequency Domain Thermoreflectance (FDTR) method under vacuum condition.We also evaluated the chemical bonding states at the interface by Laboratory Hard X-ray Photoelectron Spectroscopy (Lab. HAXPES). The measurement conditions were kinetic energy of 9.25 keV, energy resolution of 0.5 eV, energy step of 50 meV, beam diameter of 50 μm2, and detectable depth of 50 nm, respectively. Au 4f was used as a reference of the energy calibration during for the analysis. 3. Results and Discussion The thermal resistance measured from the entire Ru/TaN/(SiOx/)Si stacking structure was reported by previous studies [1]. It can be seen that the thermal resistance decreases with the increase of N2 flow rate. In order to discuss the mechanism for determination of the thermal conductance, we performed nondestructive measurements by Lab. HAXPES.Figures 1 and 2 show the photoelectron spectra obtained from Ru 3d (Ar:N2=19:1, 15:5) and Si 1s (Ar:N2=19:1, 15:5), respectively. From Fig. 1, no significant change is observed in Ru 3d spectra even within the N2 gas flow rate changes. Therefore, the cause of the change in thermal resistance with the N2 gas flow rate change cannot be found at the Ru/TaN interface. On the other hand, from the Si 1s spectrum shown in Fig. 2, it can be confirmed that the peak intensity due to Si-N or Si-O-N bonds increases with increasing N2 gas flow rate. Therefore, it can be considered that the Si-N or Si-O-N bonds formed at the TaN/(SiOx/)Si interface as the N2 gas flow rate increased promoted heat transport and contributed to the reduction of thermal resistance.In summary, the important mechanism to control the thermal resistance became clear by the non-destructive evaluation of the chemical bonding states in the multilayer stacking structure using Lab. HAXPES. Acknowledgement This work was supported by the CREST under Project No. JPMJCR19Q5 of the Japan Science and Technology Corporation (JST).

Selective oxidation of methanol to dimethoxymethane over iron and vanadate modified phosphotungstate

Iron and vanadate modified phosphotungstate was fabricated by Fe salt and vanadate incorporating into H3PW12O40. Its morphology, composition and structure were determined by XRD, SEM, TEM, FT-IR and XPS. The catalytic performance of the prepared composite for selective oxidation of methanol to dimethoxymethane using molecular oxygen as oxidant was evaluated. A detail study on influence of key reaction parameters, involving the calcination temperature of the catalyst during the preparation, reaction time, temperature and pressure, and flow rate of O2, methanol and N2 on the reactivity and selectivity was optimized. The results showed that the composite was active and highly selective for methanol oxidation, giving ca. 70% conversion of methanol and > 96% selectivity to DMM. The adsorption behaviour of methanol on surface of the catalyst or various components composed of the catalyst was investigated by in situ DRIFTS technique to identify the active sites and further considering reaction mechanism. Moreover, the operating lifetime and stability of the catalyst was also discussed.

Microstructure, Mechanical and Corrosion Properties of Chromium Nitride (CrN) Coating

Chromium nitride (CrN) films exhibit excellent corrosion and wear properties with thermal stability. CrN films are deposited on silicon (100) and EN 24 steel substrates using DC reactive magnetron sputtering. The pure Cr is used as target and films are deposited at Ar, and N2 mixtures. The N2 flow rate is kept at 10 sccm and Ar flow rate is kept at 30 sccm constant. The structural property of the films is studied using the X-ray diffraction (XRD). The average crystallite size of the films is 40 nm as calculated from Scherer's formula. The SEM images show the formation of the grains with smooth surface morphology. The hardness is studied using the microvicker hardness tester and found to increase from 260 HV to 370 HV as the temperature increased. The corrosion studies of the CrN film is studied using the salt spray test and found to have the higher corrosion resistant property

Synthesis and physico-chemistry properties of a diesel-like fuel produced from waste polypropylene pyrolysis oil

In this work, pyrolysis experiments were carried out in a stainless steel semi-batch reactor to produce a diesel-like fuel from waste polypropylene (PP). Aiming to maximize the liquid oil yield, the optimal reactor operating conditions (e. g. heating rate, batch time, degradation temperature, and N2 flow rate) was obtained by the investigation of the thermal behavior of the waste PP using Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA). The waste PP pyrolysis oil was successfully purified by adsorption onto activated carbon, resulting in a colorant removal percentage of 49.56% as well as in the removal of the particle matter. The functional groups of purified waste PP pyrolysis oil (PWPO) and the Brazilian commercial S-10 diesel fuel were obtained and compared using Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography Coupled to Mass Spectrometry (GC-MS). According to the experimental results, the proposed thermal pyrolysis process has shown a very high liquid oil yield of about 94 wt%, and fuel heavy and light hydrocarbons were identified in PWPO. It was observed that PWPO has physico-chemistry properties similar to those of commercial S-10 diesel fuel, enhancing the high lower heating value (LHV) of about 43.06 MJ/kg. The work findings pointed out the synthetic diesel-like fuel as a promising alternative for cycle diesel engines, dropping the use of fossil fuels without reducing energy efficiency.

Enhancement of hydrocarbons and phenols in catalytic pyrolysis bio-oil by employing aluminum hydroxide nanoparticle based spent adsorbent derived catalysts

The present study investigated the effects of metal loaded spent adsorbent as catalyst for the catalytic pyrolysis of pine needle biomass. Metal active sites (Ni, Fe, Cu, Zn and Mo) were introduced in alumina matrix by wet impregnation process. Non-catalytic and catalytic semi-batch pyrolysis study was carried out at conditions: 550 °C temperature, 50 °C min−1 heating rate and 200 mL min−1 N2 flow rate. Results indicated significant deoxygenation potential 3.33–35.57% of the applied catalysts towards oxygenated compounds by converting them into their corresponding hydrocarbon (27.70–36.41%) and phenolic (40.41–46.04%) derivatives. Among all the catalysts, Ni/Al and Fe/Al produced the highest quality bio-oil by enriching their carbon content to 62.93 and 60.14% and heating value to 31.41 and 26.86 MJ kg−1, respectively. Moreover, significant enhancement in their hydrocarbons (36.41 and 36.01% for Ni/Al and Fe/Al, respectively) and phenolic compounds (46.04 and 41.67% for Ni/Al and Fe/Al, respectively) from 9.15% hydrocarbons and 13.32% phenols in non-catalytic bio-oil had also been observed. Presence of CO and CO2 in the evolved gases also represented the occurrence of deoxygenation reactions during catalytic breakdown. Hydrocarbon and phenol-rich bio-oil can find its application either as a replacement for petroleum fuel or an industrial-grade chemical. Thus, catalysts derived from spent aluminum hydroxide nanoparticle adsorbent can act as an effective substitute for the currently utilized high-cost catalysts in catalytic pyrolysis of biomass.

Effect of O2 flow rate on the structure, wettability and tribo-mechanical behaviour of Zr-O-N thin films

Structural and tribo-mechanical properties of Zr-O-N films deposited by reactive magnetron sputtering in a mixture of Ar (flow rate = 80 sccm), N2 (flow rate = 20 sccm) and O2 with a varying flow rate of 0 to 12 sccm were investigated. The films were characterized using scanning electron microscopy, energy dispersive x-ray analysis, atomic force microscopy, nanoindentation and wear tests. Oxygen content have a significant effect on the microstructure, wettability, tribo-mechanical properties of Zr-O-N films. The Zr-O-N films showed a dense structure with a mixture of zirconium oxides and nitrides and the preferred orientation changed from (111) ZrN to (200) ZrN with increasing O2 flow rate. The ZrON film, deposited at an oxygen flow rate of 10 sccm exhibited the highest contact angle (147°), the highest hardness (27.1 GPa), the lowest friction coefficient (0.36) and the lowest wear rate (5.8 × 10−7 mm3·Nm−1). The improvement in the tribological performance of the ZrON film deposited at 10 sccm is attributed to the improved hardness and increased H/E and H3/E2 ratios, due to the formation of a hard solid solution by the diffusion of oxygen.

The Behavior of Supersonic Jets Generated by Combination Gas in the Steelmaking Process.

In the duplex steelmaking process, the oxygen flow rate is suppressed to reduce the increasing rate of the temperature in the molten bath, resulting in severe dynamic conditions. To improve the mixing effect of the molten bath, a Laval nozzle structure designed for combination gas has been proposed. In this research, five types of Laval nozzle structure have been built based on the combination gas content, and both numerical simulations and experiments are performed to analyze the flow field of the supersonic jet. The axial velocity and oxygen concentration were measured in the experiment, which agreed well with the numerically simulated data. The results show that both initial axial velocity and potential core length increase with the flow rate of combination gas. Further, applying a higher N2 flow rate could improve the oxygen utilization rate at different ambient temperatures, but this issue increases the oxygen utilization rate; however, the latter can be reduced at higher ambient temperatures.

Chemical recycling of end-of-life tires by intermediate pyrolysis using a twin-auger reactor: Validation in a laboratory environment

This work deals with the chemical recycling of end-of-life tires (ELT) by means of intermediate pyrolysis to produce tire pyrolysis oil (TPO), raw recovered carbon black (rCB), and tire pyrolysis gas (TPG). Here, the operational features of a twin-auger pyrolyzer, as well as the characteristics of the resulting products were satisfactorily validated in a laboratory environment. Hence, the twin-auger pyrolyzer used in this work aligns with the characteristics associated with the fourth technology readiness level (TRL-4). In order to assure this statement, both the statistical repeatability of yields and, the consistency of the product’s properties were assessed. As such, 27 experiments divided into 4 replicates were conducted at the conditions which maximized the TPO yield, while minimizing that of raw rCB: ELT mass flow rate of 1.16 kg/h, reactor temperature of 475 °C, solid residence time of 3.5 min, and N2 flow rate of 300 mL/min. Thereafter, we explored the main physicochemical properties of different pyrolysis product samples, randomly selected throughout the experimental campaign. The TPO was characterized in terms of density, viscosity, total acid number (TAN), flash point, elemental composition, heating value, distillation characteristics, and contents of both water and carbon Conradson. The contents of saturates, aromatics, resins, and asphaltenes (SARA) were also determined. The raw rCB was characterized by proximate, elemental, and heating value analyses. Textural properties such as surface area (SBET), total pore volume (VT), micropore volume (VMin), and mesopores volume (VMeso), were identified as well, including SEM images analysis. Finally, the chemical composition of the TPG was measured by quantitative gas chromatography (H2, CH4, CO, CO2, C2H6, C2H4, C3H8, H2S). The analysis of variance (ANOVA) suggested that the twin-auger pyrolyzer is repeatable in terms of TPO, raw rCB, and TPG yields, with a reliability of 95 %. Likewise, the characterization of the products revealed that their properties remained quite stable across the experimental runs. These results demonstrate the stability and suitability of the experimental facility, which leads to the conclusion that the twin-auger reactor is a reliable and promising technology for the chemical recycling of ELT by means of intermediate pyrolysis.

The adsorption of phenol on granular activated carbon prepared from waste coconut shell in Trinidad

AbstractActivated carbon (AC) produced from waste coconut shells in Trinidad and Tobago was investigated as a sustainable method for adsorption of the pollutant phenol from produced water. Activation of produced char was optimized at 900°C for 10 min using a N2 flowrate of 96 ml/min and CO2 gas at a flowrate of 96 ml/min, and the associated kinetic and thermodynamic parameters of the phenol‐AC interaction was experimentally obtained. The maximum adsorption capacity was 0.027 mg phenol/g adsorbent (equilibration time of 2 h and initial phenol concentration of 2 mg/L) and the data satisfied a pseudo‐second order kinetic model fitted indicating the chemically rate controlled mechanism. The Freundlich isotherm modeled the adsorption data best with a maximum equilibrium constant, KF of 0.138 occurring at 85°C. The standard enthalpy change and standard entropy change were 155.48 kJ/mol and 0.44 kJ/mol K respectively and the Gibbs free energy change ranged from 5.89–46.3 kJ/mol for the temperature range studied. The results obtained provide key parameters for the design of an adsorption column containing the locally produced AC adsorbent for the sustainable treatment of produced water.

Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

Investigating the effect of nitrogen on the structural and tribo-mechanical behavior of vanadium nitride thin films deposited using R.F. magnetron sputtering

Magnetron sputtering is one of the most commonly used deposition techniques, which has received considerable attention in industrial applications. In particular, owing to its compatibility with conventional fabrication processes, it can produce and fabricate high-quality dense thin films of a wide range of materials. In the present study, nitrogen (N) was combined with pure vanadium in order to form binary nitride to improve its mechanical and tribological performance. To evaluate the influence of nitrogen on the structure of the as-deposited vanadium nitride (VN) coatings, the following techniques were used: XPS, XRD, SEM, AFM and optical profilometry. The residual stresses were determined by the curvature method using Stoney’s formula. The hardness and Young’s modulus were obtained by nanoindentation measurements. The friction behavior and wear characteristics of the films were evaluated by using a ball-on-disk tribometer. The obtained results showed that the N/V ratio increased with increasing the N2 flow rate while the deposition rate decreased. The preferred orientation was changed from (200) to (111) as the N2 flow rate increased with the presence of V–N and V–O binding energies as confirmed by XPS analysis. The nitrogen addition resulted in a columnar morphology and a fine structure with fine surface roughness. The VN thin film containing 49.5 at.% of nitrogen showed the best performance: highest mechanical properties (hardness = 25 GPa), lowest friction coefficient (μ = 0.37) and lowest wear rate (Ws = 2.72 × 10−5 mm3N−1 m−1). A good correlation between the film microstructure, crystallite size, residual stress and mechanical and tribological properties was observed.

Numerical study on the effective utilization of high sulfur petroleum coke for syngas production via chemical looping gasification

This study aims at investigating the syngas production and sulfur conversion mechanisms during the chemical looping gasification (CLG) process with the industrial by-product petroleum coke (petcoke) as fuel, which is beneficial to the waste-to-energy process. The chemical kinetics including petroleum coke decomposition, char gasification, oxygen carrier reduction and the sulfur species reaction model are incorporated into the dynamic model to simulate a CLG fluidized bed reactor with iron-based oxygen carriers. Results suggest that the model is able to well predict the time-varying concentrations of the syngas products and sulfur-containing gases. The near-zero COS emission from the reactor outlet confirms the previous experimental results and contributes additional evidence that the presence of steam enhances the conversion of COS to H2S. The effects of temperature, steam and N2 flow rates on the petcoke CLG performance are also evaluated. The results indicate that higher temperature and steam flow rate lead to an improvement in the conversion of carbon and sulfur in petroleum coke. However, further increasing the gas flow rates may result in a more intense fluidization state, which might significantly facilitate the OC reduction reactions with flammable gases, thus increasing the CO2 and SO2 production in the petcoke CLG process.

Influence of growth parameters on microstructures and electrical properties of InxAl1−xN thin films using sputtering

The influence of growth parameters such as N2/Ar mixture, sputtering pressure and growth time on InxAl1−xN films is investigated. We find that with an increase in N2 flow rate from 6 to 12 and 18sccm, the RMS has substantially improved from 5.4 to 2.5 and 2.35 nm. The full width at half maximum (FWHM) is decreased as the N2 flow rate increases. The grain size and thickness shows an almost linear relationship with N2 flow rate variation. The granular structure grown at 1 Pa seems to be more compact than the sample at 1.5 Pa and 1.2 Pa. As the growth time is increased to 60, 90 and 120 min, the crystallite size is 7, 9 and 14 nm and the RMS is measured to 2.35, 3.57 and 4.14 nm, respectively. The thickness of the samples has a certain positive relationship with the pressure and growth time. In addition, we find the optimizing growth parameter is 18sccm N2 flow rate, 1 Pa pressure and 60 min growth time. The In content (x) is calculated to be 0.6. The band gap of the film is calculated to be 1.97 eV. The sheet resistance of the optimizing growth parameter is 1076 (Ω/□). We further fabricate In0.6Al0.4N photoelectric device, which is revealed to have significant photo-respond with stable photocurrent. The saturation time of the current is 0.5–0.8 s. Our work is meaningful for InxAl1−xN film layer improvement and application in the future.

Hot target magnetron sputtering enhanced by RF-ICP source for CrNx coatings deposition

This article describes hot Cr target magnetron sputtering enhanced by a radio-frequency inductively coupled plasma (RF-ICP) source in an Ar + N2 atmosphere. Optical emission spectroscopy revealed an opportunity to perform magnetron sputtering in an inert (Ar) atmosphere, while the CrNx coating can be deposited on a substrate in a chemically reactive atmosphere formed by the RF-ICP source. High stability and repeatability of deposition process were observed, and the deposition rate of the CrNx coatings increased from 106 to 127 nm/min as N2 flow rate rose. The power of the RF-ICP source and the N2 flow rate can be used to tailor and control deposition conditions. The XRD and WDS measurements showed the effect of deposition conditions on the crystal structure and elemental composition of CrNx coatings. It was found that the change of substrate bias, RF-ICP source power and N2 flow rate result in variation of coating stoichiometry from pure Cr to CrN.

Metal-doped high silica ZSM-5 nanocatalyst for efficient conversion of plastic to value-added hydrocarbons

In this work, catalytic pyrolysis of plastic was investigated using the high siliceous ZSM-5 nanocatalysts. The parent nanocatalyst with boron promoter in the structure was prepared by hydrothermal technique. The wet impregnation of molybdenum promoter (0–30 wt.%) was then carried out through a multi-step process. XRD, FT-IR, N2 adsorption-desorption, FE-SEM, TEM, TG-DTA, and NH3-TPD techniques were characterized the nanocatalysts. The modified nanocatalyst included the uniform spherical morphology and the homogenous dispersion of Mo species. Mo incorporation improved the concentration and reduced the strength of the acid sites. The NZC25 nanocatalyst had high crystallinity (100%), mesoporous structure (0.08 cm3g−1), and high surface area (259 m2g−1). The effect of different amounts of the promoter and operating conditions were studied on the catalytic activity in dual-zone fixed bed reactor. The NZC25 nanocatalyst had the best activity in catalytic pyrolysis, including high plastic conversion and high liquid product (0.51 g). The optimum operating conditions were 525 °C, catalyst to plastic ratio of 1:10, and N2 flow rate of 50 mL min−1, which resulted in the highest production (94%) of value-added hydrocarbons (C6-12). Furthermore, 99.7% of the produced oil was desirable hydrocarbons, including iso-paraffin (3.2%), aromatics (87.3%), and olefins (9.2%). The nanocatalyst showed low coke content (only 1.62%) and high reusability through the sequence cycles, including less than 10% drop of liquid production. The results showed the great capacity of the high siliceous ZSM-5 in the conversion of plastic to value-added hydrocarbons.

Influence of nitrogen partial pressure on structure, mechanical and tribological properties of TaCN coatings

The TaCN coatings were fabricated on Ti-6Al-4V by reactive magnetron sputtering with different nitrogen partial pressures. The results show that the TaCN coatings have a columnar crystal structure of TaC, TaN nano-crystal and amorphous phases (amorphous carbon and CNx). The crystallinity of TaCN coatings decreases with the increase of N2 flow rate. It is found that hardness and adhesive strength have a downward trend and friction coefficient of TaCN coatings increases with the increase of N2 flow rate. In particular, the TaCN coating with lowest N2 flow rate of 30 sccm has the highest hardness (16.3 GPa), the biggest adhesive strength (74.8 N) and the lowest friction coefficient (~0.19). The TaCN coating exhibits an excellent tribological performances even at high temperature. The lowest friction coefficient at 400 °C could reach below 0.1 thanks to the transfer layer containing graphitic clusters which generated during friction.