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Abstract A laboratory-scale capacitively coupled radio frequency (RF) plasma pyrolysis reactor working in reduced pressure has been developed. Experiments have been performed to examine the characteristics of this RF plasma reactor and the products of biomass gasification. It was found that the electrode geometry, input power and reactor pressure were the key parameters affecting the plasma characteristics such as plasma length, temperature, and energy transfer efficiency. Biomass gasification using input power 1600–2000 W and reactor pressure 3000–8000 Pa produced a combustible gas consisted of H2, CO, CH4, CO2 and light hydrocarbons as well as a pyrolytic char. On average, the gas yield can reach 66 wt% of the biomass feed. An energy balance analysis on the RF plasma pyrolysis system was also given.

Abstract To improve the quality of fast pyrolysis bio-oil, an efficient catalytic upgrading process is proposed with pristine Ni/MgO catalyst and ethanol. Esterification, hydrogenation, alkylation of aromatic ring and depolymerization of lignin-derived pyrolytic oligomers simultaneously occurred in the upgrading process. Esters, ketones and alkyl-substituted aromatic compounds were found to be the main components in the volatile fraction of the upgraded bio-oil. Under the optimal conditions, pH value and HHV (high heating value) of the upgraded bio-oil were 5.01 and 24.9 MJ kg −1 , respectively. This result suggested that the properties of bio-oil could be effectively improved by the catalytic upgrading process. Moreover, carbon efficiency of this upgrading process was relatively high because that formation of coke is suppressed in the upgrading process.

Abstract Cu doped LaCoO 3 photocatalyst by microbial synthesis (M-LaCo 0.7 Cu 0.3 O 3 ), using the extract of Pichia pastoris GS115, presents an outstanding photocatalytic performance for hydrogen production from formaldehyde solution. The structure and physicochemical properties of the photocatalyst were characterized by XRD, EDS, XPS, FTIR, Photoluminescence (PL), and UV–vis (DRS). The results indicate that copper doping contributes to the formation of impurity level and appropriate oxygen vacancy. Differing from separate citric acid complexation with metal ions, biomass intervention in preparation process can help adjust the crystal structure and surface structure of catalyst, which makes the diffraction angle and unit cell change and simultaneously modulates surface oxygen defects. Furthermore, some organic functional groups from biomass residue on the surface act as photosensitizer, so that the M-LaCo 0.7 Cu 0.3 O 3 markedly absorbs the visible light and shows higher absorbance than LaCo 0.7 Cu 0.3 O 3 and LaCoO 3 . Consequently, M-LaCo 0.7 Cu 0.3 O 3 exhibits the highest rate of photocatalytic hydrogen production (1.13 mmol h −1 g −1 ). This research provides a new way for designing and developing visible-light active materials using biomass.

Air transport plays an inevitable role in the transportation sector. In the modern world, the aviation contribution is very immense to establish worldwide developments. However, the emission released by the aviation industry is massively high. Due to the sudden increase in the air traffic the contribution of global CO2 and CO have increased in recent years. Hence the aviation sector seeks the replacement for fossil fuels. In this study, the micro gas turbine engine has been experimentally studied for different engine speeds and throttle position. The gas turbine was allowed to run in the different test fuels such as, Jet-A, A20 (20% microalgae 80% Jet-A) and A30 (30% microalgae 70% Jet-A) and the predicted results were compared. In addition to the typical experimental calibrations, machine learning has been applied to examine the differences in the both performance and emission characteristics of the biofuel blends with approximately 51 different fuel combinations using LSTM networks. Based on the predicted results, introduction of the biofuel affects the production of the static thrust. On the contrary, the emissions of the CO and CO2 were very low compared to Jet-A. With regard to the nitrogen of the oxides, no massive reduction has been witnessed despite running at different fuel conditions. Besides, the marginal decrease in the NOx was observed above 75000 rpm. ; King Saud University, KSU; Natural Science Foundation of Jiangsu Province: BK20200775, RSP-2021/257 ; Natural Science Foundation of Jiangsu Province [BK20200775, RSP-2021/257]; King Saud University, Riyadh, Saudi Arabia

The geophysical logging technology has been employed in connection with field and laboratory tests for coal reservoir evaluation in Huainan and Huaibei coalfields, China. The relationships between coalbed gas content of coal reservoir and characteristics of geophysical logs have been investigated by means of the combined analyses of experimental and geophysical logging data. Coalbed gas content of drilling core samples from coal seams was determined experimentally. The results, together with the log data obtained from geophysical logging technology, have been analyzed by using geological statistics, permitting correlation of the coalbed gas content to the log responses. The correlation developed in this study provides better understanding of the coal reservoir for coalbed methane exploration in given coalfields by an improved prediction of the coalbed gas content.

Abstract Ca2MgSi2O7 has been investigated in the transesterification of rapeseed oil with a view to determining its viability as a solid base catalyst for use in biodiesel synthesis. This catalyst exhibited both high catalytic activity and reusability, giving a fatty acid methyl ester (FAME) conversion of 99% when the reaction was conducted with 20 wt% catalyst and a methanol/oil molar ratio of 10:1 at 190 °C over 6 h. The FAME conversion remained >85% after 16 cycles without catalyst compensation. BET test illustrates that Ca2MgSi2O7 has a narrow pore size distribution centred at 5.0 nm. Transesterification takes place on the catalyst surface, the basic characteristics or basicity of the catalyst decide greatly catalytic activity. CO2-TPD analysis showed that the total number of basic sites of akermanite is 0.8822 mmol·g−1. This includes three different oxygen anions exhibiting different chemical environments on the catalyst surface. The basic strength of oxygen anions increased in the order O2

Abstract Thermogravimetric analysis (TGA) was applied to evaluate the combustion behaviour of combining three feedstocks coal, biomass and polyethylene as a tri-fuel for various blend ratios. The feed materials assessed were bituminous coal (BC), anthracite coal (AC), camphor wood (CW), wheat straw (WS) and polyethylene-terephthalate (PET). The kinetic parameters of the tri-fuel blends were assessed using a Coats-Redfern integral method. The kinetic analysis indicates that the tri-fuel combustion mechanisms follow the diffusion model (D1 & D4) and can be separated in to three distinct stages. TGA analysis demonstrated that an increase in the blend ratio of biomass (CW/WS) and plastic (PET) enhances the combustion properties with respect to lowering the ignition (Ti) and burnout (Th) temperatures, along with an increase in the combustion stability indices (Cs/Csi). This enhancement of the combustion behaviour is more evident for the lower volatile anthracite coal tri-fuel blends. As the blend ratio of the anthracite coal is lowered the overall hydrocarbon-volatile content is increased as a function of increasing the biomass and plastic blend ratios. Laboratory scale analytical analysis of blending biomass, plastic with either bituminous coal or anthracite coal demonstrates a synergistic influence which is observed to benefit the overall combustion behaviour (enhanced mass loss rate and burnout). However, further investigation of tri-fuel blending streams assessing the combustion performance (Ti, Th, Ci, Csi, Ea, flue gas emissions and ash chemistry) is required at pilot and plant scale.

Four kinds of imidazolium ionic liquids (ILs) were employed to catalyze the transesterification reaction of rapeseed oil. The effects of molar ratio of methanol to rapeseed oil, catalyst dosage, reaction temperature, and reaction time, and the deactivation of water on catalytic activity were explored. The results showed that imidazolium ILs with long alkyl chains and sulfonated groups exhibited the best catalytic activities due to their strong Bronsted acidity. The catalytic activity was depend on the -SO3H group in the cation, not the anion HSO4. Water molecules competed with the anion to bind with the protons of the imidazolium cation. This results in the disruption of the structure of ILs, leading to deactivation; increasing the reaction temperature could alleviate this negative effect of water. The yield of fatty acid methyl ester (FAME) remained constant (similar to 85%) at 130 degrees C, when the water content increased from 1 wt% to 5 wt%. The highest yield of FAME for the catalyst 1-butylsulfonate-3-methyl imidazolium hydrogen sulfate ([BSO3HMIM][HSO4]) could reach 100% under optimum conditions. (C) 2016 Elsevier Ltd. All rights reserved.

Using high free fatty acids (FFAs) contents oil as the raw material for biodiesel production can reduce the production cost and make fully use of the bio-oil resources. Macroporous cation exchange resins contain numerous acid sites to catalyze heterogeneous esterification reactions to reduce the FFAs contents and prevent the saponification reaction. This study focuses on the synthesis and performance tests of the macroporous resin catalysts and its water deactivation mechanism. Self-synthesized macroporous cation exchange resins have a surface area of 185 m(2) g(-1) with an average pore diameter of 9.7 nm and the ion exchange capacity is 3.37 +/- 0.11 mmol g(-1). Owing to their pore structure, macroporous resin performs better than gel-type resin in low methanol concentration or high FFAs contents, but they show physical instability in reusability tests. The FFAs conversion reaches 97.8% (substrate oil with acid value of 64.9 mg KOH/g) under 100 degrees C and a methanol/FFAs molar ratio of 15:1 with 10 wt% catalyst loading. Water that originally exists in oil or that is produced in the reaction deactivates differently on the activity of the resin, but this deactivation can be decreased by increasing the reaction temperature. In this study, a linear relationship between original water content and esterified FFAs was identified and differences in deactivation models were investigated. (C) 2015 Elsevier Ltd. All rights reserved.