Influence of reaction atmosphere (H2O, N2, H2, CO2, CO) on fluidized-bed fast pyrolysis of biomass using detailed tar vapor chemistry in computational fluid dynamics

Secondary pyrolysis in fluidized bed fast pyrolysis of biomass is the focus of this work. A novel computational fluid dynamics (CFD) model coupled with a comprehensive chemistry scheme (134 species and 4169 reactions, in CHEMKIN format) has been developed to investigate this complex phenomenon. Previous results from a transient three-dimensional model of primary pyrolysis were used for the source terms of primary products in this model. A parametric study of reaction atmospheres (H2O, N2, H2, CO2, CO) has been performed. For the N2 and H2O atmosphere, results of the model compared favorably to experimentally obtained yields after the temperature was adjusted to a value higher than that used in experiments. One notable deviation versus experiments is pyrolytic water yield and yield of higher hydrocarbons. The model suggests a not overly strong impact of the reaction atmosphere. However, both chemical and physical effects were observed. Most notably, effects could be seen on the yield of various compounds, temperature profile throughout the reactor system, residence time, radical concentration, and turbulent intensity. At the investigated temperature (873 K), turbulent intensity appeared to have the strongest influence on liquid yield. With the aid of acceleration techniques, most importantly dimension reduction, chemistry agglomeration, and in-situ tabulation, a converged solution could be obtained within a reasonable time (∼30 h). As such, a new potentially useful method has been suggested for numerical analysis of fast pyrolysis

Leverage of Environmental Pollutant Crump Rubber on the Dry Sliding Wear Response of Epoxy Composites.

The effect of crump rubber on the dry sliding wear behavior of epoxy composites is investigated in the present study. Wear tests are carried out for three levels of crump rubber (10, 20, and 30 vol.%), normal applied load (30, 40, and 50 N), and sliding distance (1, 3, and 5 km). The wear behavior of crump rubber-epoxy composites is investigated against EN31 steel discs. The hybrid mathematical approach of Taguchi-coupled Grey Relational Analysis (GRA)-Principal Component Analysis (PCA) is used to examine the influence of crump rubber on the tribological response of composites. Mathematical and experimental results reveal that increasing crump rubber content reduces the wear rate of composites. Composites also show a significant decrease in specific wear values at higher applied loads. Furthermore, the coefficient of friction also shows a decreasing trend with an increase in crump rubber content, indicating the effectiveness of reinforcing crump rubber in a widely used epoxy matrix. Analysis of Variance (ANOVA) results also reveal that the crump rubber content in the composite is a significant parameter to influence the wear characteristic. The post-test temperature of discs increases with an increase in the applied load, while decreasing with an increase in filler loading. Worn surfaces are analyzed using scanning electron microscopy to understand structure-property correlations. Finally, existing studies available in the literature are compared with the wear data of the present study in the form of a property map

Experimental investigation on compression ignition engine powered with pentanol and thevetia peruviana methyl ester under reactivity controlled compression ignition mode of operation

In the current study, an effort is carried out to study the influence of pentanol as low reactive fuel (LRF) along with diesel and Thevetia peruviana methyl ester (TPME) as high reactive fuels (HRF) in reactivity controlled compression ignition (RCCI) engine. The experiments are conducted on dual fuel engine at 50% load for RCCI mode of operation by varying pentanol percentage in injected fuels. The results revealed that RCCI mode of operation at 10% of pentanol in injected fuels exhibited higher brake thermal efficiency (BTE) of 22.15% for diesel and pentanol fuel combination, which is about 9.1% and 27.3% higher than other B20 and pentanol, B100 and pentanol fuel combinations respectively. As the percentage of pentanol increased in injected fuels, hydrocarbon (HC) and carbon monoxide (CO) emissions are increased while nitrogen oxide (NOx) and smoke emissions are decreased. Among various fuel combinations tested diesel and pentanol fuel combination gives lower HC, CO and smoke emissions and higher NOx emissions. At 10% pentanol in injected fuels, the highest heat release rate (HRR) and in-cylinder pressure are found for diesel and pentanol fuel combinations compared with other fuels

Investigation of flexural properties of epoxy composite by utilizing graphene nanofillers and natural hemp fibre reinforcement

This study aims to determine the optimum reinforcement required to attain the best combination of flexural strength of modified green composites (graphene oxide + hemp fibre reinforced epoxy composites) for potential use in structural applications. An attempt was also made for the combination of graphene and hemp fibres to enhance load-bearing ability. The infusion of hemp and graphene was made by the weight of the base matrix (epoxy composite). Results showed that graphene reinforcement at 0.4 wt.% of matrix showed load-sustaining capacity of 0.76 kN or 760 MPa. In the case of hemp fibre reinforcement at 0.2 wt.% of the matrix, infusion showed enhanced load-bearing ability (0.79 kN or 790 MPa). However, the combination of graphene (0.1 wt.% graphene nanofillers) and hemp (5 wt.% hemp fibre) indicated a load-sustaining ability of 0.425 kN or 425 MPa, whereas maximum deflection was observed for specimen with hemp 7.5 % + graphene 0.2 % with 1.9 mm. Graphene addition to the modified composites in combination with natural fibres showed promising results in enhancing the mechanical properties under study. Moreover, graphene-modified composites exhibited higher thermal resistance compared to natural fibre reinforced composites. However, when nanofiller reinforcement exceeded a threshold value, the composites exhibited reduced flexural strength as a result of nanofiller agglomeration

Sustainable adsorption method for the remediation of malachite green dye using nutraceutical industrial fenugreek seed spent

Nutraceutical industrial fenugreek seed spent (NIFGS), a relatively low-cost material abundantly available with nearly negligible toxicity for the bioremediation of malachite green (MG) dye from aqueous media, is reported. Studies on the various parameters affecting the adsorption capacity of NIFGS were carried out to evaluate the kinetics and the equilibrium thermodynamics. All the experiments were designed at about pH 7. The adsorption isotherm model proposed by Langmuir fits better than the Freundlich isotherm model. Kinetic study data confirms the viability of pseudo-second-order model. Calculated thermodynamic factors suggest that the adsorption phenomenon is endothermic, almost instantaneous, and physical in nature

Numerical and experimental studies of irregular-shape biomass particle motions in turbulent flows

This paper discusses numerical and experimental studies of biomass micro scale particles motion in turbulent flows. The biomass micro size particles are extremely anisotropic and typically of irregular shape with sizes varying between 200–6000 μm in length and 125–1400 μm in diameter. Four different types of biomass micro size particles from different sources are applied. Ten different numerical modelling tools for simulation of the biomass micro size particles motion in turbulent flow are presented and validated against experiments. The experiments are carried out using three different techniques: an aerodynamic classifier, vibrating sieve and microscopic image analysis. Results showed considerable discrepancy between the models and the experiments. In consequence, a comprehensive new shape factor correlation for the irregular-shape particles is proposed, which enhances significantly the model results. Parametric studies are also carried out, including influence of particle shape, size, and anisotropy criteria. Moving orientation of the irregular-shape particles in turbulent flow is addressed as well. Results demonstrated that the key issue for modelling of biomass micro size particle motion in turbulent flow is both drag coefficient and particle-projected area. Small size of biomass particle is quickly accelerated and it tends to follow airflow; larger biomass micro size particle is slowly accelerated and it decelerated rapidly because of less response to air stream. Additionally, both small and large biomass micro size particles tend to orient themselves to one preferable direction

Analysis of Uncoupling Protein 1 and β3-adrenergic Receptor Single Nucleotide Polymorphisms in Saudi Population with Type 2 Diabetes Mellitus

BACKGROUND: Uncoupling proteins (UCP) and β3-adrenergic receptor (ADRB3) gene polymorphism have been implicated in the susceptibility to type 2 diabetes mellitus (T2DM) but the results are inconsistent and inconclusive. AIM: The aim was to investigate the relationship between -3826A/G (rs1800592) of UCP 1 and ADRB3 Trp64Arg (C/T) (rs4994) gene polymorphism and the incidence of T2DM among Saudis. METHODS: Genotyping of both UCP1 and ADRB3 genes was carried out in 110 healthy controls and 108 unrelated Saudis with T2DM using polymerase chain reaction-based restriction fragment length polymorphism. RESULTS: The genotype and allele frequencies of the UCP1 gene did not differ significantly between diabetic subjects and controls (p > 0.05). However, the CT genotype and the T allele of ADRB3 were higher in diabetic subjects compared with the controls while the CC genotype and C allele were higher in the controls relative to the diabetic subjects (Odds ratios [OR]: 7.85, 95% confidence interval [CI]: 4.23–14.59, p < 0.001 and OR: 7.434 95% CI: 4.026–13.39, p < 0.001, respectively). CONCLUSION: The UCP1 -3826A/G polymorphism may not be associated with the susceptibility to T2DM among Saudis while T allele of ADRB3 may be related to the risk of T2DM, whereas the CC genotype and C allele may confer protection to T2DM