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Fast pyrolysis of the mixed plastics (PE: PP: PS: PVC = 0.5: 0.3: 0.15: 0.05) with and without hydrothermal dechlorination pretreatment were investigated in a fixed bed reactor to determine the effects of pyrolysis parameters (temperature, carrier gas flow rate and particle size) on the distribution and the quality of the products. The results showed that high pyrolysis temperature, high carrier gas flow rate and small particle size promoted the migration of organic chlorine in condensable products to inorganic chlorine in gas products. And the optimal conditions for fast pyrolysis of mixed plastics to produce oil were the pyrolysis temperature of 500 °C, carrier gas flow rate of 40 ml/min and particle size of 0.1–0.15 mm with the maximum oil yield of 67.88 wt%. Hydrothermal pretreatment of mixed plastics has shown an excellent dechlorination efficiency of 99.9 %. Furthermore, the total yield of oil and wax was increased by 7.06 wt%, meanwhile the content of C5-C9 components in the pyrolysis oil showed an upward trend when compared with fast pyrolysis without pretreatment. Besides, the concentration of methane achieved 50.68 % due to the possible weakening effect of hydrothermal pretreatment on C C bond energy of β-position.

Levoglucosan is served as a significant versatile product to generate high value-added chemicals and pharmaceutical additives. Levoglucosan was predominately produced from pyrolysate of cellulose. However, the direct fast pyrolysis of waste biomass produces a small quantity of levoglucosan in comparison with the theoretical value of cellulose. This study explored Fenton pretreatment as a possible route to enhance levoglucosan yield during the fast pyrolysis of the waste corncob. The experimental results showed that different Fenton pretreated conditions and pyrolytic temperatures played vital roles in the formation of levoglucosan. The levoglucosan yield from fast pyrolysis at 500 °C of corncob pretreated by Fenton reaction of 14 mL/g H2O2 and 16 mM FeSO4 was about 95% higher than that of the untreated corncob. Additionally, Fenton pretreated corncob was capable of obtaining the levoglucosan at a low pyrolytic temperature (300 °C). It was mainly attributed to the effective disrupting of biomass structures and the selective degradation of lignin and hemicellulose during pretreatment. Furthermore, the powerful removal of alkali and alkaline earth metals during Fenton pretreatment was beneficial to increasing the levoglucosan yield. These findings demonstrate that Fenton pretreatment can provide a novel effective method to enhance levoglucosan yield during biomass fast pyrolysis.

Piper nigrum is an important aromatic plant, and its fruits (black and white pepper) are commonly used as food additives and spices. However, its stems were disposed as wastes. This research comprehensively investigated bioactive alkaloids of the stems, eight new dimeric amide alkaloids and eight known compounds were obtained. All obtained compounds showed excellent anti-inflammatory activity. Additionally, the dimeric amide alkaloids enhanced the anticancer effect of paclitaxel against cervical cancer cells. These results demonstrate that the stems of P. nigrum could be the sustainable source of bioactive alkaloids for development and utilization in the food and health fields.

Low-temperature solid oxide fuel cells (LT-SOFCs) are a promising next-generation fuel cell due to their low cost and rapid start-up, posing a significant challenge to electrode materials with high electrocatalytic activity. Herein, we reported the bimetallic nanoparticles encapsulated in carbon nanotubes (NiFe@CNTs) prepared by carefully controlling catalytic pyrolysis of waste plastics. Results showed that plenty of multi-walled CNTs with outer diameters (14.38 ± 3.84 nm) were observed due to the smallest crystalline size of Ni-Fe alloy nanoparticles. SOFCs with such NiFe@CNTs blended in anode exhibited remarkable performances, reaching a maximum power density of 885 mW cm

We study the strategic investment for green product development (GPD) in a supply chain. We develop a stylized two-period model in which either the retailer or the manufacturer could decide to invest in GPD in the second period. We find that the manufacturer investing in GPD is dominating because both supply chain members could earn more and the manufacturer could save more on the environmental tax. Under certain conditions, the prices are lower in the second period. However, the corresponding demand in the second period is always lower than the first period when the products become green.

A photonic quasi-crystal fiber (PQF) with high birefringence based on ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) is described. There are two elliptical air holes in the core to increase birefringence and the outer air hole array has a twelve-fold Stampfli-type quasi-crystal structure. ZBLAN reduces absorption loss in the infrared region resulting in higher birefringence. The birefringence and confinement loss of the PQF are analyzed numerically by the full-vector finite element method. Birefringence is higher than that of conventional polarization-maintaining fibers due to the two elliptical air holes in the center and reaches the maximum of 4.15×10−2 at a wavelength of 2 μm. The novel structure has great potential in high-performance optical devices.

Micro electrical discharge machining (micro EDM) provides an alternative in generating complex 3-D micro features in difficult-to-machine materials. The micro EDM performance depends not only on machining parameters but also on the microstructures and micro-characteristics of materials. The effect of free surface layer of austenitic stainless steel on the micro EDM performance is investigated in this paper. Experiments are carried out by machining multilayer stainless steel workpieces without and with surface treatment (acid pickling and oxidation treatment). Surface layer model is built to demonstrate the increasing influence of surface layer on micro EDM performance when the size of workpiece is decreased. The surface free energies of AISI 304 workpieces are estimated by measuring the contact angles. The results show that the steel workpiece with oxidation treatment has the highest surface free energy and the highest material removal rate compared with those without treatment and with acid pickling treatment. The influence of surface layer of steel workpiece on micro EDM performance is more significant when the discharge energy is lower due to size effects. Taper ratio of machined holes on steel workpiece without treatment is much higher than those of holes on steel workpieces with acid pickling and oxidation treatment. As a conclusion, surface treatment of steel workpiece before machining is an effective method to improve the machining efficiency and machining precision of micro EDM, especially when involving the sub-micro or nano-machining where machining is conducted on the workpiece surface.

Background: Pancreatic cancer is a highly fatal disease and is becoming an increasingly common cause of cancer mortality. The extent of pancreatoduodenectomy for pancreatic head cancer is still controversial, and more high-level clinical evidence is needed. We compared the outcomes of standard pancreatoduodenectomy (SPD) with those of radical pancreatoduodenectomy (RPD) with retroperitoneal nerve resection in pancreatic head cancer patients in this multicentre randomized controlled trial. Methods: RAPNER was open-label, multicentre randomised trial, patients aged 18–80 years with stage I or II pancreatic head cancer undergoing curative resection were enrolled at 6 centres from China. Patients were allocated (1:1) by use of a computer-based randomisation service to assigned to receive standard pancreatoduodenectomy (PD) or radical PD, with the latter followed by the combined dissection of additional lymph nodes (LNs), nerves and soft tissues 270° on the right side surrounding the superior mesenteric artery and celiac axis. This trial is registered with Chinese Clinical Trial Registry (http://www.chictr.org.cn), ChiCTR-TRC-12002548. Findings: Between October 3, 2012, and February 15, 2017, 468 patients were enrolled; of these, 400 were randomly assigned to the RPD group (n=201) or the SPD group (n=199). The operation time was longer with RPD than with SPD, but the R1 resection rate was slightly higher in the SPD group (12·56%) than in the RPD group (8·46%). Both the total number of retrieved LNs and number of positive LNs were significantly higher in the RPD group (20 (7-63) and 1 (0-29)) than in the SPD group (15 (7-63) and 1 (0-11)). Both the morbidity and inpatient mortality rates were comparable between the two groups. The median overall survival (OS) of the RPD and SPD groups were 23·0 months and 20·2 months (p=0·100), and the disease-free survival (DFS) were 15·6 months and 13·5 months (p=0·060). In the subgroup with a preoperative CA19-9 level less than 200 U/ml, the median OS in the RPD group was 30·8 months, which was significantly longer than that in the SPD group (20·9 months; p=0·009), and the median DFS was significantly longer in the RPD group than in the SPD group (22·3 months vs. 15·0 months, p=0·002). Furthermore, clinical benefit could be found in the RPD group in the subgroup of well & moderate histological differentiation, preoperative CEA level less than 5·00 ng/ml, R0 resection and postoperative adjuvant chemotherapy based on DFS analysis. A multivariate Cox proportional hazards model showed that initial CA19-9≥200 U/ml, N1 stage and poor differentiation suggested poor OS. Radical resection achieved equivalent prognosis regardless of perineural invasion except for aortic nerve plexus invasion. The RPD group exhibited significantly lower locoregional and mesenteric LN recurrence rates but a higher peritoneal seeding frequency. The RPD group also exhibited significantly less back pain intensity 6 months after surgery than the SPD group. Interpretation: This study suggests that in pancreatic head cancer patients, RPD with retroperitoneal nerve resection does not provide a significant survival benefit compared with SPD. RPD can be performed safely, and be considered a treatment option with improving prognosis for patients with a low chance of systemic metastasis in pancreatic head cancer. Trial Registration: ChiCTR-TRC-12002548. Funding Statement: Sun Yat-sen University Clinical Research 5010 Program (Grant No. 2012007), China; National Natural Science Foundation of China (Grant No. 81871945). Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was approved and overseen by the clinical ethics committee of each participating hospital.

The study presented a novel approach microwave pyrolysis coupled conventional pre-pyrolysis (MCCP) to dispose of the stalk for syngas and biochar. Impacts of preheating temperature (250 ∼ 450 °C) on pyrolysis property and products characteristics were investigated. Compared with microwave-assisted pyrolysis (MAP), the initial time for rapid temperature ramp in MCCP was distinctly advanced from 124 s to within 20 s; the biochar yields significantly increased from 24.19% to 33.24%, and the H

A new inorganic-organic hybrid solid, namely, Zn2(dmen)3B10O14(OH)6 (dmen = N, N′-dimethylethylenediamine) was prepared under solvothermal conditions. This compound has a molecular structure with B5O7(OH)3 clusters bridged and decorated by zinc–amine complexes. It is a direct-gap material with a band gap of 5.21 eV. The band structure and density of states of the compound were also calculated based on density functional theory.

A novel method for preparing porous carbon materials from biomass pyrolysis vapors with calcium citrate template has been proposed. The effects of pyrolysis temperature, pyrolysis heating rate and carbon-containing precursor preparation temperature on the yield of biomass pyrolysis products, composition of light bio-oil and structure of porous carbons were investigated. The physicochemical characterization and hydrogen adsorption experiments were carried out for the prepared porous carbons. The carbonization mechanism of the carbon-containing precursor was studied and a five-stage reaction kinetic model was established by Gaussian peak separation method according to the DTG curves. Under the optimal conditions of pyrolysis temperature (823 K), heating rate (10 K/min) and carbon-containing precursor preparation temperature (473 K), the prepared porous carbon material has the largest specific surface area of 1703 m2/g, relatively high micropore volume of 0.51 cm3/g and microporosity of 24.17%. The hydrogen adsorption capacity of the carbon material can reach 170.12 cm3/g (1.53 wt%) at 77 K at atmospheric pressure. This paper provides a novel and environmental-friendly method for the preparation of porous carbon materials, and also presents a new way for the utilization of biomass pyrolysis vapors before condensation.

Biomass waste pyrolysis has taken an increasing interest in producing biofuels and bio-based chemicals, but the complex compositions of pyrolytic liquid hinder its development and utilization. To address these challenges and improve the yield of target chemicals (levoglucosan) and aromatics, a novel two-stage process based on NaOH-Fenton pretreatment coupled with fast pyrolysis is firstly proposed. Firstly, rice straw was pretreated by dilute alkali to separate lignin fractions, and then the residue was further treated via Fenton reaction at room temperature to obtain cellulose-rich substrate. The fast pyrolysis of raw rice straw produced the complex compositions in the pyrolytic liquid. After NaOH-Fenton pretreatment, the target platform chemicals in the pyrolysate were effectively concentrated. The cellulose-rich substrate exhibited a very high absolute yield of levoglucosan (201.9 mg/g) as compared to raw rice straw (not detected). The lignin fractions recovered from this process were catalytically fast pyrolyzed for preparing aromatic fuels. Furtherly, the maximum removal rates of nitrogen (76.5%) and sulfur (93.3%) were achieved by the coupled process. A short-chain cellulose-rich substrate with similar dissociation energy of glycosidic bonds was formed by the NaOH-Fenton process based on the analytical results of the DFT calculation and mechanism. The similar dissociation energy of C–O bonds from the short-chain cellulose-rich substrate favors the formation of high-yield levoglucosan in subsequent fast pyrolysis. This work introduces a simple and highly efficient strategy to convert grass biowaste into value-added chemicals and liquid fuels.

A novel CeO2-MoO3-WO3/TiO2 (CMWT) catalyst was prepared by a single step sol-gel (SG) method. It exhibited 93.8%–98.9% of NO conversion at 275–450 °C and high tolerance to 10% H2O and 1000 ppm SO2 at a gas hourly space velocity (GHSV) of 90,000 h− 1. Superior SCR activity of CMWT catalyst could be attributed to the presence of more Ce3 + and chemisorbed oxygen, higher redox ability, stronger adsorption capacity of NH3 species and the strong interaction among ceria, molybdenum, tungsten and titania.

As a novel catalyst for oxygen reduction reaction (ORR), nitrogen-doped carbon xerogel was prepared via a sol-gel followed by the subsequent pyrolysis in ammonia atmosphere and post-treatment process. The resultant catalysts were characterized by BrunauereEmmetteTeller (BET), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) analysis and electrochemical measurements. The role of metal in the catalyst was studied by comparing catalytic activities of the catalysts with and without post-treatment. Results show that the catalyst with nitrogen doped on the surface possesses an amorphous microstructure. The catalysts with and without post-treatment showed almost the same ORR electrocatalytic activities, which clearly demonstrated the negligible influence of metal removal on ORR performance. The catalyst with post-treatment displayed comparable ORR activity to that of Pt/C in alkaline medium as well as superior stability. A maximum power density of 115 mW cm −2 at 40 °C was achieved on the single cell with the as-prepared catalyst as cathode, demonstrating its application as promising alternative for Pt-based electrocatalysts in direct borohydride fuel cells.

Graphitic mesoporous carbon xerogel (GMCX) with high surface area and comparable mesoporous structure is prepared via a sol–gel process with cobalt acetate, followed by the subsequent pyrolysis in nitrogen flow at 1800 °C. 20 wt.% Pt/GMCX catalyst is synthesized using the as-prepared GMCX powder as support. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterizations for Pt/GMCX indicate that Pt nanoparticles dispersed on GMCX have a much smaller average nanoparticle size and narrower size distribution than Pt nanoparticles grown on commercial XC-72 carbon black and GCX powder which we reported before. The results of linear sweep voltammetry (LSV) test demonstrate that the Pt/GMCX catalyst exhibits a higher oxygen reduction reaction (ORR) electrocatalytic activity than commercial Pt/C and Pt/GCX. The corrosion resistance of the catalysts was evaluated by potential cycling accelerated aging test (AAT). Pt/GMCX catalyst exhibits very nearly the same Pt electrochemical active surface area (EASA) retention as Pt/GCX (53.3% for Pt/GMCX and 53.0% for Pt/GCX), which is higher than that of commercial Pt/C (39.2%). Combined with its facile synthesis process, GMCX powder is a promising substitute for commercial Pt electrocatalyst support in achieving high catalytic activity and good durability for ORR.

Electrical discharge machining (EDM) and emerging electro-arc machining (EAM) are machining processes sharing a similar material erosion mechanism. However, the input parameters and the output responses of them exhibit significant differences. To gain a deeper understanding of these differences, a study was performed adopting single pulse discharges and machining parameters covering EDM and EAM. A full factorial experiment including 50 trials with consideration of the polarity, the discharge current, and the pulse duration, was designed and carried out. For more detailed research and for the sake of comparison, the trials were divided into die-sinking EDM, short pulse EAM, normal EAM, and low current EAM. While the crater geometries including the heat affected zone diameter, the crater depth, the white layer thickness, the removal volume, and the removal ratio, were acquired as results and analyzed. The heat affected zone diameter under both polarities grew with increasing the discharge current and longer the pulse duration. The crater geometry of EDM and EAM was similar when positive polarity was adopted. The crater under negative polarity became shallower as the discharge current decreased and as the pulse duration increased: this led to a significant difference between EDM and EAM. Furthermore, the removal volume and the removal ratio exhibited similar trends. The shallow craters of negative polarity with little removal volume were likely to appear in the normal EAM and low current EAM trials. The characteristics of EAM are such that the high discharge current and the long pulse duration together result in a large material removal rate (MRR) while the long pulse duration alone results in a low electrode wear ratio (EWR). However, the removal ratio of EAM is lower than that of EDM.

Electrical discharge machining (EDM) is one of the most promising non-traditional micro-scale machining methods. Because several operating parameters that are insignificant in macro EDM cannot be neglected during micro EDM process, models derived from the macro EDM process may be inappropriate at the micro scale. This paper contains a comprehensive review of size effects in traditional micro-machining and characteristics specific to micro EDM compared to macro EDM techniques. The very concept of size effects in micro EDM is thoroughly defined and three categories of effects are presented: material microstructure, processing parameter and thermal conduction size effects. Future potential research directions on the subject are also summarized. We assert that careful research and precise attention must be given to size effects in micro EDM. Size effect information especially benefits the machining speed and machining precision of micro EDM.

This study aims to report on the feasibility of enhancing light olefins production from ex-situ catalytic fast pyrolysis (CFP) of biomass by co-feeding with steam and determine the role of steam. Effects of steam on catalyst and pyrolysis/catalysis reactions in ex-situ CFP were investigated using a two-stage fluidized-bed/fixed-bed reactor. Carbon yield of olefins + monocyclic aromatic hydrocarbons (MAHs) increased by 23.80% after proper steam dealumination of HZSM-5 framework, which suggests that HZSM-5 can be activated at the initial exposure to steam. For activated HZSM-5, olefins carbon yield increased by 35.65% and olefins to MAHs (O/M) ratio boosted from 0.83 to 1.60 as steam concentration in carrier gas increased from 0% to 40%, while the total carbon yield of olefins and MAHs still kept at the same level. Steam enhanced olefins production by: (1) promoting the formation of light compounds in bio-oil, which are the main precursors of hydrocarbons, during pyrolysis; (2) inhibiting aromatization reactions during catalysis. It provides a possibility for the control of O/M ratio of hydrocarbon products and the enhancement of light olefins production from CFP of biomass.

A high-birefringence(HB) photonic quasi-crystal fiber(PQF) with all-circular air holes is designed and ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN) is used to increase the birefringence and reduce confinement loss of the PQF in the infrared region. The structure of the PQF is analyzed and optimized numerically using the full-vector finite element method by adopting the perfectly matched layer boundary conditions. The PQF possesses higher birefringence in the wavelength range between 1.3 and 1.8μm and the maximum birefringence value of 4.1×10−2 is achieved at 1.55μm. This is the highest birefringence value reported from all-circular-hole PQFs so far suggesting that the novel structure has great potential in high-performance optical devices.

Based on inverse piezoelectric effect, a new micro-EDM method called piezoelectric self-adaptive micro-EDM was proposed in this paper. The tool structure and working principle of this new method is simple and it is different from the conventional micro-EDM system. A piezoelectric actuator with high resolution and high response frequency was employed as the micro driven mechanism in this system. Because of the special structure, this new technology could regulate the discharge gap depending on discharge condition and even could realize self-elimination of short circuits during machining process. Working principle and processing of the new method was introduced, and the distinct machining characteristics were analyzed in this paper. Based on orthogonal experimental design and S/N analysis method, the effects of machining parameters such as open voltage, capacitance, current-limiting resistance, spindle rotational speed and initial feed speed on surface roughness (SR) were researched. The experimental results show that the open voltage and capacitance were the main influence factors. With the increase of open voltage and capacitance, the SR rapidly increased.

Piezoelectric self-adaptive micro electrical discharge machining (micro-EDM) is a new micro-EDM technology, which is based on inverse piezoelectric effect. Compared to conventional micro-EDM, piezoelectric self-adaptive micro-EDM can obtain better machining performances by facilitating the ejectment of debris and reducing the abnormal discharge. However, micro size effects also occur in piezoelectric self-adaptive micro-EDM, which can result in the difficulty to predict and optimize the machining results. In this paper, the working principle and advantages of piezoelectric self-adaptive micro-EDM are presented and the theory of similarity is introduced to quantify the size effects. The evolutions of machining time and tool wear length of micro-EDM with and without piezoelectric actuator are evaluated by discussing the similarity precision and similarity difference. It is found that the similarity precision and similarity difference increase with the decrease of the scale of the open-circuit voltage, regardless of whether the micro-EDM is with or without piezoelectric actuator. It is indicated that micro-EDM is more susceptible to the size effects in the case of machining with lower open-circuit voltage. Both the similarity precision and similarity difference of machining time of micro-EDM with piezoelectric actuator are lower than those of conventional micro-EDM. It is concluded that the smoother machining process of piezoelectric self-adaptive micro-EDM can result in a weaker size effects, so the machining performances of piezoelectric self-adaptive micro-EDM are easier to be predicted. The similarity theory is an effective method for investigating the size effects in the micro-EDM.

Electrical discharge machining (EDM) gets the advantage of less cutting force. However, a transient force named the impulse force exists in the machining process. The impulse force has effects on the efficiency, stability and accuracy of EDM. The peak current plays a major role in the impulse force, which has been studied and verified. However, the effects of other process parameters on the impulse force are lack of systematically study. Five single-factor experiments adopting different dielectric medium, polarity, gap width, tool geometry, and immersion depth, were designed and carried out. The single pulsed power source used in the experiments had constant discharge durations by detecting and shutting discharge current, which made the experiments to get rid of the randomness of discharge durations and be accurate. However, the vibration characteristics of the force sensor were changed by the dielectric medium, the fixture and the electrode weight, which made the measure of the impulse force to be complicated. The force balance method was simplified and adopted to acquire the maximum impulse force. It was found that these machining parameters had effects on the impulse force. There was little impulse force when the dielectric medium was air. The impulse force of positive polarity was a little higher than that of negative polarity. The impulse force of sphere tools was larger than that of needle tools. The increasing of gap width or immersion depth enlarged the impulse force. Moreover, the gap width had effects on the crater diameter while the depth of immersion did not. It is verified that these process parameters affected the impulse force by their effects on the bubble.

A MoO 3 modified CeO 2 /TiO 2 catalyst was prepared by a single step sol–gel method for selective catalytic reduction of NO with NH 3 . The experimental results indicates that MoO 3 modified CeO 2 /TiO 2 catalyst exhibited higher SCR activity and resistance to 10% H 2 O and 1000 ppm SO 2 . From the characterization results, it can be concluded that good physical properties, highly dispersed active species of Ce and Mo, more appearance of Ce 3+ and chemisorbed oxygen, strong interaction among ceria, molybdenum and titania, and high oxygen storage capacity might contribute to the excellent deNO x performance of CeO 2 –MoO 3 /TiO 2 catalyst prepared by a single step sol–gel method.

A Ce–W–Ti mixed oxide catalyst prepared by a single step sol–gel method exhibited excellent SCR activity and high resistance to H2O and SO2. The excellent catalytic performance might be attributed to the improved dispersion of Ce species on TiO2, the increase in the amount of Ce3+ and chemisorbed oxygen and the strong interaction among ceria, tungsten and titania owing to the addition of WO3.

This paper considers optimization of time average admission rate in an energy-constrained network system with multiple classes of data flows. The system operates regularly over time intervals called frames, while each frame begins with a fixed-length active period and ends with a variable-length idle period. At the beginning of the frame, the system chooses a service mode from a collection of options that affect the class and the amount of data flow served as well as the energy incurred in the active period. After service, the system chooses an amount of time to remain idle. The optimization goal is to make decisions over time that maximizes a weighted sum of admitted data rates subject to constraints on queue stability and energy expenditure. However, conventional solutions suffer from a curse of dimensionality for systems with large state space. Therefore, using a generalized Lyapunov optimization technique, we design a new online control algorithm that solves the problem. The algorithm can push time average admission rate close to optimal, with a corresponding tradeoff in average queue backlog. Remarkably, it does not require any knowledge of the data arrival rates and is provably optimal.

Chemical looping co-gasification of pine wood and polyethylene with CaO/Fe2O3 oxygen carrier was preliminarily conducted in a fixed bed reactor and thermogravimetric analyzer (TGA). The effects of Fe2O3 /biomass mass ratio, temperature and steam/biomass mass ratio on the product distribution (syngas yield, H2/CO ratio and cold gas efficiency) during the pine wood chemical looping gasification were investigated. Results showed that the optimal product distribution was obtained at the gasification temperature of 850 °C with the Fe2O3/feedstock ratio of 0.25 and steam/biomass mass ratio of 0.25. The interactions of pine wood and polyethylene were further studied. It was found that the positive or even the synergetic effects existed, which resulted in the enhancement of syngas and hydrogen yield. The optimal addition of 75% polyethylene increased H2 yield from 0.62 Nm3/kg to 1.59 Nm3/kg compared to the pine wood chemical looping mono-gasification. Chemical looping co-gasification also improved the cold gas efficiency from 77.22% to 89.30% and H2/CO ratio from 1.54 to 1.88. The CaO/Fe2O3 mass ratio of 1.0 was sufficient to elevate the H2/CO ratio above 2. The maximum H2 yield of 1.73 Nm3/kg, cold gas efficiency of 92.23% and H2/CO ratio of 2.09 were finally obtained to meet the demand for the Fischer-Tropsch synthesis. The presence of synergetic effects on syngas and hydrogen yield from the fixed bed data but their absence from the TGA data revealed the interaction mechanism could be attributed to gas phase reformation and cracking reactions.

Internal flows of pure vapor experiencing film condensation on the bottom wall of an inclined (horizontal to vertical) channel and the inside wall of a vertical cylinder are studied. The annular flow regime considered here has turbulent (or laminar) vapor in the core and thin laminar condensate on the wall. Both smooth and wavy interfaces are considered. We propose a theory which yields a new general asymptotic form of interfacial shear, addresses solvability of the governing equations, gives the solution of the equations near the point of onset of condensation and facilitates implementation of one- or two-dimensional numerical schemes for the entire flow. The results, in a suitable limit, are shown to be in excellent agreement with a classical exact solution. We implement a one-dimensional numerical solution scheme to assess popular interfacial shear models and heat transfer correlations. These assessments, based on comparison of computational p:redictions with data from well-known experiments, identify two potentially good interfacial shear models which can be further developed for greater reliability.