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A catalytic transfer hydrogenation of castor oil using glycerol-based is a process of adding hydrogen to the castor oil to produce hydrogenated castor oil with the addition of 10% Pd/C as the catalyst and glycerol as a hydrogen donor. The reaction occurred at the reaction temperature of 178 °C for an hour. To prove whether glycerol can be one of the hydrogen donors like limonene that is commonly used, the research started by using pure glycerol as the hydrogen donor and as a control to determine the protocol. A direct heating apparatus connected with a reflux system was used for this experiment. The result from FTIR along with the melting point shows the formation of hydrogenated castor oil from this reaction. The increment in melting point value and the absence of C=C peak (1655.79 cm−1) from FTIR spectrum shows that the catalytic transfer hydrogenation successfully occurred. The melting point of the hydrogenated castor oil is 65 °C and the melting point of castor oil is − 7 °C. Therefore, it was proven that, the glycerol can be used as the hydrogen donor for the castor oil for a catalytic transfer hydrogenation reaction.

The catalytic and non-catalytic pyrolytic conversion kinetics of palm kernel shell (PKS) with untreated (as received) and H2SO4-treated coal bottom ash as catalyst were investigated in this study. Flynn-Wall-Ozawa (FWO) and distributed activation energy model (DAEM) isoconversional kinetic models were exploited to evaluate the kinetic parameters. The study was conducted using thermogravimetric analysis at 10, 20, 30, and 50 °C/min heating rates. The activation energy (Ea) and pre-exponential factor (A) for non-catalytic PKS decomposition for DAEM ranged from 74.39 to 217.05 kJ/mol and 4.77E+01 to 1.99E+14 s−1 at different conversions while for the untreated ash, the ranges were 103.84–402.53 kJ/mol and 7.35E+03–1.04E+29 s−1. In the decomposition with treated ash, Ea and A were 81.79–191.07 kJ/mol and 1.61E+02–1.20E+12 s−1 for 7 wt% ash and 74.41–137.35 kJ/mol and 4.91E+03–4.53E+08 s−1. Values of Ea and A obtained for FWO followed the same pattern and are in close agreement with that obtained using DAEM. The use of 10 wt% acid-treated ash reduced the activation energy compared with the non-catalytic process by about 33.05% while the untreated ash increased the activation energy. The kinetic parameters were determined satisfactorily using the first-order reaction mechanism.

Anaerobic digestion (AD) is one of the renewable technologies and a good alternative for the management of livestock manure. The present study focuses on co-digestion of fresh chicken manure (FCM) with corn stover (CS) experiments for biogas production. The objective of this study is to evaluate the effect of corn stover in the production of biogas and methane content by co-digestion. The mixing ratios of co-digestion of FCM with CS were 1:1, 1:2, and 2:1. The total solids for co-digestion were 8% for all ratios. The results showed that the ratio of 2:1 produced the highest biogas yield (46.7 m3/ton of slurry) and 53.2% of methane purity. The pH fluctuated around a range of 5.2 to 7.9 due to different stages of anaerobic digestion as a result of microbe’s activity.

Bio-char is a carbon-rich solid material generated by thermochemical conversion process (pyrolysis) of lignocellulosic biomass, and its viability as a sustainable material has received increasing attention for environmental remediation. The relationship between bio-char properties and its applicability as a soil amendment is still not conclusive. The purpose of this research is to study the bio-char physical and chemical properties from an agricultural residue to examine the quality criteria for carbon sequestration and agricultural uses. Pyrolysis temperature was shown to have a strong impact on production and characteristics of bio-char samples. The bio-char yield decreased with increasing temperatures (350–550 °C). According to proximate and ultimate analysis data, temperature has the strongest impact on carbon stability of bio-char (stability increased at higher temperature). The volatile matter decreased while fixed carbon content increased with the increase of pyrolysis temperature. To evaluate further bio-char quality, the relationships between (O/C and H/C molar ratio) and (H/C and volatile matter) of raw paddy husk and produced bio-char at various temperatures is proposed. SEM, FT-IR, and 13C NMR findings are in well agreement with thermogravimetric and proximate analysis of the bio-char that structural and physicochemical properties were significantly influenced by pyrolysis temperature. CO2 adsorption rate increased with increasing temperature. Bio-char produced at 450 °C showed higher absorption capability and could be a potential sustainable substrate for C sequestration and soil amendment.

Thermogravimetric data, the Coats–Redfern free integral method, and correlation coefficients obtained by use of different reaction models were used to study the kinetic characteristics of non-catalytic and catalytic pyrolysis of biomass. Zeolite catalysts (ZSM-5, MCM-22, and ITQ-2) were mixed with the biomass in the ratio 1:10. Analysis of thermogravimetric data revealed that thermal decomposition occurred at 240–450 °C for both non-catalytic and catalytic pyrolysis of biomass. Two temperature regions, region I 240–330 °C and region II 360–450 °C, were identified and a best-fit model describing the behavior of non-catalytic and catalytic biomass pyrolysis was obtained. Addition of catalyst reduces the activation energy in first region then increases it in the second region for all reaction orders. Chemical reaction and diffusion-controlled reaction mechanisms could be kinetically characterized and enabled good description of the nature of biomass pyrolysis.

International audience; AbstractKey messageHot pressing leads to changes in wood water sorption properties, linear viscoelastic behavior, and chemistry. In hot-pressed hybrid poplar, storage modulus linearly correlates with cellulose apparent crystallinity index and degree of polymerization, revealing the impact of cellulose hydrolysis on wood viscoelasticity during hot pressing.ContextHeat treatment and densification during hot pressing are known to alter wood chemical, physical, and viscoelastic properties. Interrelationships between these properties and their changes during hot pressing are, however, unknown. They are expected to play a significant role on mat consolidation during the manufacture of wood-based composites.AimsThis study aims (1) to characterize the impact of hot pressing on the physical, viscoelastic, and chemical properties of hybrid-poplar wood and (2) to assess possible relationships between these properties.MethodsDry and moist wood samples were hot-pressed under various conditions of temperature. Specific gravity, water sorption isotherms, and dynamic viscoelastic properties of hot-pressed wood were measured together with cellulose apparent crystallinity and molecular weight. Possible relationships between these properties were assessed with statistical analyses.ResultsWood specific gravity, sorption isotherm, dynamic moduli, and cellulose crystallinity were all affected by the hot-pressing conditions. The viscoelastic response of hot-pressed wood was found to relate not only to the extent of densification but also to in situ molecular properties of cellulose. Cellulose apparent crystallinity index and degree of polymerization in hot-pressed wood linearly correlated with storage modulus, revealing the importance of cellulose hydrolysis during hot pressing on wood viscoelastic response.ConclusionDuring hot pressing, wood cellulose hydrolysis appears to govern the viscoelastic response, in addition to wood densification.

Thermal modification of wood constituents occurs upon hot-pressing of flakes during consolidation of oriented strand board (OSB). Hence, the effects of hot-pressing of hybrid poplar on water-soluble extractives were studied. Poplar veneers were pre-conditioned to 0 or 8 % moisture content and subsequently hot-pressed at 150, 200 or 250 °C. Aqueous extracts were characterized by conventional chemical methods in conjunction with chromatography (HPLC and SEC), mass spectrometry (ESI–MS) and spectroscopy (FTIR) analysis. Water-soluble fractions were markedly influenced by thermal compression treatment at 250 °C compared to the lower temperatures. Chromatographic results indicate that water-soluble extractives content increases with temperature while the degree of polymerization decreases with detection at low temperature levels. FTIR spectroscopic analysis indicates changes in aqueous-extracts composition of wood monosaccharides (hemicelluloses), meanwhile ESI–MS detected xylo-oligosaccharides. These results clearly show that heat treatment dictated the changes in each water-soluble extractive component and they respond independently with different treatment.