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Thailand has plentiful rubberwood biomass for biofuel and bioenergy applications, as well as for carbon material production. One of the keys to choosing a biomass conversion process is its effects on the physicochemical properties. In addition, thermochemical conversion of biomass also requires knowledge of its thermal decomposition behavior and kinetics for reactor design; and specification of operating conditions. Thus, the aims of this research were to explore the physicochemical properties of rubberwood biomasses (RWBs) generated alternatively from branches, trunks, and roots. The rubberwood biomass with the best energy properties was then selected to investigate its thermal decomposition behavior and kinetics. The physicochemical properties of RWBs determined were the gross and elemental components, energy properties, lignocellulosic components, and major noncombustible elements. Thermal decomposition observations were carried out by using the thermogravimetric analyzer under a nitrogen atmosphere at heating rates of 5, 10, 20, and 30 °C min−1. The kinetic analysis was conducted by applying the iso-conversional model-free methods of Friedman, Kissinger–Akahira–Sunose (KAS), and Ozawa–Flynn–Wall (OFW). Based on statistical analysis, the results highlighted that the trunks (RTT) possessed the best energy properties. The lignocellulosic and elemental components of RWBs had small differences. The activation energy derived from iso-conversional methods demonstrated consistency with previous studies. The activation energies were in the ranges 159.11–210.61, 168.89–175.06, and 169.96–176.01 kJ mol− 1 according to the Friedman, KAS, and OFW methods, respectively. These explorations are useful for applying the RWB as feedstock in torrefaction and pyrolysis applications. [ABSTRACT FROM AUTHOR]

This study investigated the behavior and syngas characteristics of oil palm biomass fluidized bed gasification (FBG) with alternative inlet air configurations. The air was supplied to the combustion zone of the FBG with tangential and updraft air inlet (TI and UI) modes. A mixed oil palm decanter cake was used as feedstock at 3 kg/h feed rate. The experiments were done at the equivalence ratios (ERs) from 0.1 to 1.0. The experimental results showed that the air supply mode and ER affected the temperature distribution inside the gasifier. Operation with TI mode had combustion initiated at the side, then propagated through the middle section, while in UI mode, the combustion reaction was at the center of the chamber. With TI mode, the temperature at combustion zone was around 600 °C. At ER 0.5, this zone covered the heights from 0.25 to 0.75 m. In UI mode, the highest temperature was near 800 °C, but combustion was prominent only in a zone near the bottom. The CFD simulations showed that the alternative inlet air configurations and the ER influenced flow patterns. CFD confirmed the swirling streamlines in TI mode, while UI mode showed a localized elevated temperature, particularly at 0.25 m height. Syngas composition analysis indicated that operation in TI mode at ER of 0.7 provided the larger combustion zone, leading to better syngas product in terms of CO (> 20%) and H2 (> 8%) components. This mode also provided the best 5.1 MJ/m3 energy content for syngas. The results of this study can provide useful guidelines for further investigations of FBG with tangential air inlet. [ABSTRACT FROM AUTHOR]

Improving energy content and hydrophobic nature of woody biomass can be pursued through torrefaction. This gives torrefied biomass with a low bulk density, potentially increasing storage and transport costs. To overcome this issue, densifying the torrefied biomass is necessary. However, poor binding of particles makes densification challenging without using a binder. Therefore, the aim of this study was to investigate the physicochemical characteristics and techno-economic aspects of torrefied rubberwood biomass (TRWB) when pelletized using various cassava-based binders at different blending ratios. The selected binders included cassava starch (CS), cassava pulp (CP), and cassava chip (CC). Each binder at 5%, 10%, or 15% (wt.) was mixed with TRWB and water before pelletizing using a flat die machine. The results revealed that pelletizing TRWB with different cassava-based binders at various blending ratios influenced the physicochemical characteristics of the TRWB pellets, particularly dimensions, bulk density, fuel and atomic ratios, and energy content. The TRWB pellets demonstrated energy densities in the range of 7.95–11.39 GJ/m3, and their mechanical durability and fine content fell within acceptable ranges. The TRWB pellets maintained their shape during 120 min of water soaking, with water absorption levels varying by binder dose. The pelletizing ability, material, and energy costs of TRWB pellets depend on binder type and dose. CP can be applied as a binder for pelletizing torrefied rubberwood biomass. However, the mechanical durability of the product needs to be above the user requirement or standard. [ABSTRACT FROM AUTHOR]

Production of coffee beans generates various types of biomass that can be applied as bioenergy for drying and roasting the beans. Thus, the aims of this study were to explore the characteristics of coffee biomass pellets (CBPs) produced from coffee cherry pulp (CCP), coffee parchment (CPM), and expired green coffee beans (ECB) by single and co-pelletization. The CBPs were then used to produce the synthesis gas in a downdraft gasifier, and the syngas properties were investigated for further heat applications. The results showed that single and co-pelletization of CCP and CPM performed well. The CBPs had good physiochemical properties in shape, size, and atomic ratios. The higher heating value and energy density of CBPs were 19.25–24.29 MJ/kg and 12.09–14.87 GJ/m3. The ash from CBPs was rich in K2O, CaO and MgO oxides, and the CPM ash had the lowest initial deformation temperature at 1136 °C. The ash samples from CBPs also had different slagging and fouling indexes. The syngas from CBPs mainly contained H2 (6.85–9.30%), CO (12.15–18.85%), and CO2 (10.85–13.75%). The heating value and tar concentration of syngas from CBPs were 3.24–4.32 MJ/m3 and 21.75–30.92 g/m3. The main chemical compounds in tar were styrene, phenol, caffeine, and pyrrole according to GC–MS. These results indicate that CCP and CPM have potential for pelletization and gasification to generate heat needed for coffee bean processing. [ABSTRACT FROM AUTHOR]

Wastes from oil palm plantations and mill processing are renewable resources for bio-energy and biochemicals development. The five most abundant oil palm wastes are empty fruit bunch (EFB), palm kernel shell (PKS), palm mesocarp fiber (PMF), palm frond (PF), and palm trunk (PT). These different types of biomass have different properties which can significantly influence the bio-oil products and pyrolysis performance. Bio-oil and biochar were produced by slow pyrolysis of these wastes in a fixed-bed reactor at 600 °C for 60 min. The biomass and pyrolysis products were comparatively characterized using thermogravimetric analysis (TGA), elemental analysis, Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC–MS), and scanning electron microscopy (SEM). The highest yield (25.5 wt%) of bio-oil was obtained from PF, while the highest yield (29.7 wt%) of biochar was obtained from PMF. Fatty acids were the main compounds in bio-oil obtained from EFB and PMF, while those from PKS, PF, and PT contained more aromatics and their boiling point distributions were lower than EFB and PMF bio-oils. Biochar from all the materials decomposed in two stages and showed similar compositions. The variations in the yields and properties of products resulted from differences in the properties of feedstocks. The results could contribute useful data for selection and controlling the pyrolysis of oil palm wastes. [ABSTRACT FROM AUTHOR]

Biofuel is a sustainable and ecologically friendly energy source that evolved from the usage of non-edible oil and has witnessed substantial growth in demand in recent decades. Biodiesel is primarily made from organic sources, such as edible and non-edible vegetable oils, and is then profiled before use. This research will look into the potential of producing biodiesel from neem oil. The biodiesel was made utilizing a trans-esterification procedure that gave saponification values of 191 mg KOH/g, iodine of 10 mgl2/g, acid of 14.0 mg KOH/g, the density of 0.91 g, a viscosity of 23 mm2/s, and flash point of 266 °C. The improvement of lubricating oil characteristics is crucial for protecting engines, bearings, and machine components from friction and wear, as well as minimizing energy spent combating friction. Lubricant tribological and rheological properties are crucial for wear prevention in unchanged environments. The use of particle and filamentous nanofillers increases these properties, allowing the lubricating oil to be more stable under extreme working conditions. The purpose of this study is to investigate the improvement in neem biodiesel performance following the addition of multiwalled carbon nanotubes (MWCNTs) in six modest compositions, namely, 0, 0.03, 0.06, 0.09, 0.12, and 0.15 wt.% MWCNT. Besides this, the additions of MWCNTs have been studied and documented in terms of flash and pour points, thermal conductivity, kinematic viscosity, friction coefficient, and wear. The MWCNTs were characterized using X-ray diffraction. The addition of MWCNTs raised the pour point and flash point, although there was unpredictability after the 0.09 wt.% composition. Thermal conductivity and kinematic viscosity are enhanced continuously and notably. The friction coefficient and wear scar diameter were lowered to 0.09 wt.% MWCNTs before reversing attributed to accumulation and non-uniformity. When all of the studied attributes were taken into account, a composition of 0.09 wt.% was determined to be optimal. This formulation provided improved tribo-film and hydrodynamic lubrication consistency was maintained. [ABSTRACT FROM AUTHOR]

During transesterification reactions, catalyst content, free fatty acids (FFA), and water content affect the final ester content, which is also impacted by soap formation that is yet to be completely elucidated. This research aimed to examine the effects of reaction time (0–10 min), FFA content (0.2–1.1 wt%), and potassium methoxide amount (KOCH3 0.5–2.42 wt%) during the transesterification reaction of refined palm oil containing 0.49 wt% FFA. Soap formation occurred during the first few seconds of the reaction, and then, the soap content remained relatively constant. From a microscopic point view, soap should act as a mass-diffusion barrier reducing reactant mass fluxes to the reaction zone. High FFA content in palm oil causes high soap formation. A high-water content leads to soap formation in FAME and RPO. FFA contributes to soap formation due to neutralization and saponification reactions. It was found that the optimal catalyst content to meet biodiesel property standards (i.e., particularly that the ester content is greater than 96.5%) was 1.0 wt% of oil. Catalyst addition below 0.7 wt % resulted in diesel that did not meet the required ester content standard. Catalyst addition exceeding 1% did not improve the conversion further, but it increases the production costs. Regarding the effects of the type of catalyst on the 2nd step transesterification of FAME, the use of potassium hydroxide showed more soap formation than potassium methoxide. The results suggest that the drawbacks associated with high catalyst utilization should be addressed. [ABSTRACT FROM AUTHOR]

This study investigated experimentally pyrolysis of rubberwood sawdust (RWS), sewage sludge (SS), and their blends (25:75, 50:50, and 75:25 by weight) in an agitated bed pyrolysis reactor. The yields and characteristics of liquid product and biochar were determined for pyrolysis at 450, 500, and 550 °C and were affected both by temperature and feedstock type. The liquid and biochar yields were in the ranges 27.30–52.42 and 21.43–49.66 (wt%). Pyrolysis of RWS at 550 °C provided the highest liquid yield, while SS gave a high biochar yield. Co-pyrolysis of SS with RWS improved yield and quality of liquid and biochar products. The liquid product had 57.54–70.70 wt% of water and a low hydrocarbon content. The higher heating value (HHV) of water-free liquid product was 14.73–22.45 MJ/kg. The major compounds of liquid product included acetic acid, 2-propanone, 1-hydroxy, and phenols according to GC-MS. The biochar from RWS had a high carbon content (83.37 wt%) and a high HHV (33.57 MJ/kg), while SS biochar was mainly ash (67.62 wt%) with low carbon content. The SS biochar also had high contents of Si, Ca, Fe, K, and Mg as determined by XRF. Co-pyrolysis of SS with RWS improved the biochar by increasing its carbon content and reducing ash and inorganic elements. The surface of RWS biochar was more porous, while SS biochar had the larger specific surface according to SEM and BET. Based on these results, co-pyrolysis of 75:25 feedstock mix is recommended for further studies on applications of liquid product and biochar. [ABSTRACT FROM AUTHOR]

The objective of this work is to evaluate the potential of oil palm biomass (OPB) in terms of physicochemical properties for producing biofuels via pyrolysis processes. The OPB included oil palm trunk (OPT), oil palm fronds (OPF), oil palm shell (OPS), oil palm roots (OPR), oil palm decanter cake (OPDC), empty fruit bunches (EFB), oil palm fiber (OPFB), and oil palm sewage sludge (OPSS). Their physicochemical properties are considered on several physical, chemical, and thermal aspects. The results showed that particle size distribution and bulk density of ground OPB were different. The proximate analysis results of OPB were consistent with the lignocellulose content and extractives. The carbon and hydrogen content of the OPB were also correlated with the organic components. Some OPB contained high lignin and extractives. The lignin content of OPB strongly influenced to thermal decomposition trend. OPB contained high inorganic elements such as potassium (K), calcium (C), and iron (Fe). The higher heating value and potential use as energy equivalent with fossil fuels of the OPB were relatively low. OPB had low thermal conductivity, and the dielectric constant, loss factor, and tangent loss of the OPB were also low. Thus, these results will be beneficial for the researchers and biofuel producers for choosing the appropriate OPB, as well as the operating conditions and reactor types. [ABSTRACT FROM AUTHOR]

Solar food drying is a well-established food-conserving process in India. Various researchers had developed solar dryer models which were usually validated using experimental observations and numerical simulation processes that are time-consuming and money-consuming. Computational fluid dynamics (CFD) simulation software facilitates the simulation of the models and gives same results in a comparatively small frame of time. This research paper is focused on CFD simulation, validation of design, energy analysis and numerical computation for domestic direct-type solar dryer for which experimental observations were performed at Ludhiana in November 2006. The design and simulation of the domestic direct-type multi-shelf dryer at no load condition are performed using ANSYS Fluent 14.0 software. The temperature of the air inside the dryer is found to be 326 K, which validates the design and purpose of the domestic direct-type multi-shelf dryer. The embodied energy of the constituents used in the construction of dryer is obtained as 339.015 kWh, and the energy payback time and carbon credit are found to be 7.57 years and INR 2055, respectively. The convective heat transfer coefficient for the dryer varies from 2.4 to 2.8 W m−2 °C−1. Coefficient of determination is estimated to be 0.98 under no load condition which shows the fare agreement between predicted and experimental value. [ABSTRACT FROM AUTHOR]

Coating with top-spray fluidized bed at inappropriate operating condition not only provides low product quality but also leads to low coating efficiency and improper energy consumption. The objective of this study was therefore to study the effects of superficial air velocity (Vf), atomization air pressure (Ap), and recycled exhaust air (Ra) on the performance of top-spray fluidized bed coating (TSFBC) in terms of product quality, coating efficiency (CE), and energy consumption for producing turmeric extract coated rice (TECR). The experimental results showed that the operation of TSFBC without Ra provided the final moisture content (MC) of TECR lower than 12 % (wet basis (w.b.)) for all Vf's and Ap's. The lowering final MC of TECR below 11.8 % (w.b.) led to the fissure of all TECR kernels. The Ra with 80 % could significantly reduce the number of fissured kernels and the energy consumption of electric heater by 41.7-46.5 %. The operation of TSFBC at low Vf, i.e., 2 m/s, resulted in high number of uncoated white rice kernels (UCWR) for all Ap's and Ra. When the Vf was increased to 2.5 or 3 m/s, the number of UCWR was significantly reduced and the value of CE was higher than that at 2 m/s. At such both velocities, the Ap and Ra insignificantly affected the CE but the Ra slightly affected the number of UCWR. [ABSTRACT FROM AUTHOR]