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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/m 3 , 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., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This investigation explored the intensive characteristics of biomass and biochar from oil palm trunk (OPT) and oil palm fronds (OPF) for supporting the increasing demand of solid biofuels in Thailand. The characteristics of these samples were also compared to low grade sub-bituminous coal (LGSBC). The results indicate that converting OPT and OPF to biochar not only enhanced the fuel ratio and atomic ratios, but it also improved the energy content. The higher heating values (HHV) of OPT and OPF biochars were 26.92 and 28.05 MJ/kg. The fuel ratio, atomic ratio and HHV of biochars were better than those of LGSBC and biomass forms. Thermal decomposition and combustion characteristics of biomass and biochar from OPT and OPF were clearly different in N2and air atmospheres. The biomass and biochar from OPT and OPF had high contents of alkali elements, consequently their ashes had high concentrations of some oxides like SiO2 and K2O. Biomass and biochar ashes from OPT and OPF had low initial deformation temperature (IDT). The IDT of OPT biochar ash was the lowest (907 °C), while the IDT of ash from LGSBC was above 1500 °C. The slagging and fouling indexes of biochars were clearly different from the LGSBC and biomass forms. Therefore, biomass and biochar from OPT and OPF have potential for solid biofuel use, and they are promising for further upgrading and applications. The user needs to be concerned with ash related problems like ash fusion, slagging, and fouling during combustion of these solid biofuels.

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]

Oil palm biomass is a non-woody lignocellulosic biomass that has a high potential at the south of Thailand for biofuels and bioenergy applications. Pyrolysis of oil palm biomass to produce biofuels such as bio-oil, biochar, and pyrolysis gas is still challenging. The aim of this study was therefore to investigate the yields and qualities of pyrolysis products obtained from oil palm trunk (OPT), oil palm fronds (OPF), and oil palm shell (OPS) using an agitated bed pyrolysis reactor. These biomasses were pyrolyzed at pyrolysis temperatures of 400, 450, and 500°C while the other operating parameters were fixed. The results showed that the different types of oil palm biomass and pyrolysis temperatures affected the product yields and qualities. The OPF pyrolyzed at 500°C provided the highest liquid yield. The liquid product contained a relatively high water content with a low pH value, leading to highly-oxygenated compounds as indicated by gas chromatography-electron ionization/mass spectroscopy technique (GC-EI/MS). The higher heating value (HHV) of the liquid product was 18.95-22.52 MJ/kg. The biochar had a relatively high HHV ranging from 25.14 to 28.45 MJ/kg. Scanning electron microscopy (SEM) indicated that the resultant biochar had a porous structure surface with a surface area of 1.15-4.43 m2/g as indicated by BET. The pyrolysis gas contained a low composition of combustible gases, leading to a low HHV.

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]

This study investigated the quantitative and qualitative attributes of liquid product and biochar obtained from pyrolysis of woody biomass (rubberwood sawdust (RWS)) and non-woody biomasses (oil palm trunk (OPT) and oil palm fronds (OPF)). The prepared biomass was pyrolyzed at temperatures of 500 °C, 550 °C, and 600 °C by using an agitated bed pyrolysis reactor, and then the yields and characteristics of liquid product and biochar were determined. The results showed that liquid product and biochar yields were in the respective ranges of 35.94–54.40% and 23.46–25.98% (wt.). Pyrolysis of RWS at 550 °C provided the highest liquid yield. The energy content of the water free liquid product was in the range 12.19–22.32 MJ/kg. The liquid product had a low pH and it mainly contained phenol groups as indicated by GC-MS. The biochars had high carbon contents (75.07–82.02%), while their oxygen contents were low (14.22–22%). The higher heating value (HHV) of biochar was in the range 26.42–29.33 MJ/kg. XRF analysis revealed that inorganic elements had higher contents in biochar than in the original biomass. The slagging and fouling indexes of biochar were also different from those of the biomass. High carbon content of the biochar confirms potential for its use in carbon sequestration. The specific surface of biochar was lower than that of biomass, while the average pore diameter of biochar was larger than for raw biomass as revealed by BET and SEM. These results on liquid product and biochar obtained from RWS, OPT, and OPF demonstrate that they are promising feedstocks for biofuels and other value-added products.

This study investigated the characteristics of biochars derived from the pyrolysis of rubberwood sawdust (RWS) and sewage sludge (SS) and their co-pyrolysis at mixing ratios of 50:50 and 75:25. Biochars were produced at 550 °C through slow pyrolysis in a moving bed reactor and then characterized. Results showed that the rubberwood sawdust biochar (RWSB) had high carbon content (86.70 wt%) and low oxygen content (7.89 wt%). By contrast, the sewage sludge biochar (SSB) had high ash content (65.61 wt%) and low carbon content (24.27 wt%). The blending of RWS with SS at the mentioned ratios helped enhance the gross and element contents of the biochar samples. The elemental analysis of the biochars was also reported in the form of atomic ratios (H/C and O/C). The functional groups of biochars were observed by Fourier-transform infrared spectroscopy (FTIR). X-ray fluorescence spectroscopy (XRF) revealed that the biochar from SS contained a high content of inorganic elements, such as Si, Ca, Fe, K, Mg, P, and Zn. The pH of the biochars ranged from 8.41 to 10.02. Brunauer, Emmett, and Teller (BET) and scanning electron microscopy (SEM) showed that RWSB had a lower surface area and larger pore diameter than the other biochars. The water holding capacity (WHC) and water releasing ability (WRA) of the biochars were in the range of 1.01–3.08 mL/g and 1.19–52.42 wt%, respectively. These results will be the guideline for further application and study of biochar from RWS, SS, and blended samples. [ABSTRACT FROM AUTHOR]

Rubberwood biomass is widely available in the southern region of Thailand and it has high potential for biofuel applications. Applications of this biomass still have some limitations, however, such as low energy properties and high biological decomposition. Therefore, the aim of this study was to enhance the fuel properties of rubberwood biomass by a torrefaction process. Rubberwood sawdust (RWS) was torrefied at different temperatures (200, 250, and 300 °C) and for various times (20, 40, and 60 min) in a moving bed reactor. The product yield and characteristics of torrefied RWS were investigated. Results showed that the solid yield of torrefied RWS was in the range of 39.07–88.69%, depending on temperature and time. The fuel atomic ratios of torrefied RWS were better than of raw RWS. The energy content and energy density of torrefied RWS were clearly enhanced (19.78–27.17 MJ/kg and 4.94–6.59 GJ/m3). ICP-OES results revealed a variation of inorganic elements in torrefied RWS, which was consistent with the ash components given by XRF. Ash fusion temperature of raw RWS and torrefied RWS ashes was stable at 1458 °C. The slagging index of torrefied RWS was decreased, while its fouling index was elevated. [Display omitted] • Yield and properties of torrefied RWS were clearly influenced by temperature. • Fuel atomic ratios and energy properties of RWS were improved by torrefaction. • Fusion temperature of torrefied RWS ash was above 1458 °C. • Torrefaction increased fouling index of RWS but reduced its slagging index. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the physicochemical changes and energy properties of torrefied rubberwood sawdust (RWS) produced in various sizes of moving bed reactors for further pelletization. The results indicate that the torrefaction of RWS with a small-scale reactor at higher temperatures led to a stronger degree of torrefaction (DT) based on various indicators. Torrefaction at 250 °C for 60 min provided appropriately torrefied RWS with solid yield, energy yield, energy content, and energy density of 70.23%, 81.20%, 22.20 MJ/kg, and 5.40 GJ/m3, respectively. The RWS with higher DT was coal-black instead of brown, as indicated by its L*, a* and b* color coordinates. The changes in color and DT were also consistent with the improvements in fuel ratio, atomic ratios, lignin content and functional groups (FTIR). SEM imaging and BET adsorption also confirmed the surface changes from raw RWS to torrefied RWS. At the same nominal conditions, torrefaction of RWS with a larger scale reactor gave a small difference in solid yield and in properties of the torrefied RWS. In addition, the production and energy costs are the key concerns in a large-scale operation. These results support pursuing further applications, like the pelletization of torrefied RWS. [Display omitted] [ABSTRACT FROM AUTHOR]

Bioenergy has gained great interest in the recent years for being environmentally friendly and renewable energy resource. Southern Thailand is well-known for agro-industry including rubber tree plantations and processing, which provide biomass that could be applied to produce bioenergy. Thus, this study aimed to investigate the energy potential of Rubber Wood Chips (RWC), Rubber Wood Pellets (RWP), Unburned Char (UBC) from rubber wood, blended RWC:UBC (50:50%) and blended RWP:UBC (50:50%). The physiochemical properties including bulk density, proximate composition, ultimate composition, heating value, Thermogravimetric Analysis (TGA), and lignocellulose content were determined for the biomass samples. The thermochemical conversion of biomass to syngas was performed using a downdraft gasifier operated at equivalence ratio 0.3. The results showed that the biomass was rich in carbon (content ranging from 44.77 to 58.54%) making it suitable for use as a solid fuel for gasification or combustion. The moisture contents of the biomass samples were below 10%. The contents of volatile matter in RWC and RWP were 74.40 and 75.40%, respectively. The UBC had a high fixed carbon content (50.60%) and comparatively low volatile matter (19%). The bulk densities of RWC, RWP and UBC were 193, 555 and 177 (kg/m3), respectively. The TGA showed the maximum weight loss of RWC and RWP around 400 °C, but this was at 800 °C for UBC. The higher heating values of RWC, RWP and UBC were 17.8 MJ/kg, 17.4 MJ/kg and 19.3 MJ/kg, respectively. The RWC and RWP had high cellulose and hemicellulose contents while UBC was rich in lignin. The syngas obtained from any of these biomass samples was mainly CO (10.81-22.67%) and CH4 (0.06-3.16%) with the lower heating value ranging from 2.78 to 4.72 MJ/Nm3. These results indicate that rubber wood biomass in various forms has relatively high potential for bioenergy applications via gasification, and it can help to support the renewable energy sector in Thailand. [ABSTRACT FROM AUTHOR]

This study investigated the quantitative and qualitative attributes of liquid product and biochar obtained from pyrolysis of woody biomass (rubberwood sawdust (RWS)) and non-woody biomasses (oil palm trunk (OPT) and oil palm fronds (OPF)). The prepared biomass was pyrolyzed at temperatures of 500 °C, 550 °C, and 600 °C by using an agitated bed pyrolysis reactor, and then the yields and characteristics of liquid product and biochar were determined. The results showed that liquid product and biochar yields were in the respective ranges of 35.94–54.40% and 23.46–25.98% (wt.). Pyrolysis of RWS at 550 °C provided the highest liquid yield. The energy content of the water free liquid product was in the range 12.19–22.32 MJ/kg. The liquid product had a low pH and it mainly contained phenol groups as indicated by GC-MS. The biochars had high carbon contents (75.07–82.02%), while their oxygen contents were low (14.22–22%). The higher heating value (HHV) of biochar was in the range 26.42–29.33 MJ/kg. XRF analysis revealed that inorganic elements had higher contents in biochar than in the original biomass. The slagging and fouling indexes of biochar were also different from those of the biomass. High carbon content of the biochar confirms potential for its use in carbon sequestration. The specific surface of biochar was lower than that of biomass, while the average pore diameter of biochar was larger than for raw biomass as revealed by BET and SEM. These results on liquid product and biochar obtained from RWS, OPT, and OPF demonstrate that they are promising feedstocks for biofuels and other value-added products. [ABSTRACT FROM AUTHOR]

• Pyrolysis and co-pyrolysis of RWS and OPT by using moving bed reactor were studied. • Yield and characteristics of bio-oil, biochar and gas were determined and analyzed. • Bio-oil from RWS was better than those from OPT and RWS mixed with OPT. • Co-pyrolysis enhanced yield and quality of bio-oil, biochar and gas. • RWS and OPT are challenging feedstocks for pyrolysis and co-pyrolysis. This study investigated the yields and characteristics of bio-oil, biochar and pyrolysis gas obtained from pyrolysis and co-pyrolysis of rubber wood sawdust (RWS) and oil palm trunk (OPT) by using an agitated bed pyrolysis reactor. Co-pyrolysis of RWS and OPT was performed at the mixing ratio of 50:50 (wt.). The biomass samples were pyrolyzed at temperatures of 400, 450, and 500 °C under specific conditions. The results indicated that the yields of the bio-oil, biochar and pyrolysis gas were in the ranges of 38.5-46.5, 22.27-28.68 and 30.1-36.9 wt.%, respectively. Pyrolysis of RWS at 500 °C provided the most bio-oil. Co-pyrolysis of RWS and OPT could improve the product yield and quality. The bio-oil had relatively high water content, while its pH was low. The main compounds of bio-oil were oxygenated compounds such as acetic acid, phenols and 2-Propanone, 1-hydroxy-, determined by GC-MS. The higher heating value (HHV) of bio-oil ranged from 16.1 to 20.36 MJ/kg. The biochar had high carbon content and low oxygen content in proximate and ultimate analysis, and based on FTIR. The HHV of biochar was in the range from 26.35 to 29.6 MJ/kg. The biochar also was highly porous, which was revealed by SEM and BET. The pyrolysis gas mainly contained CO, CO 2 , H 2 and CH 4 , and its heating value was in the range from 3.23 to 6.7 MJ/m3. Based on these results, the RWS and OPT are alternative and challenging biomasses for conversion to biofuels and value-added products via pyrolysis. [ABSTRACT FROM AUTHOR]

This study's goal is to maximize the yield of pyrolysis oil utilizing lychee-based biomass for a quick pyrolysis process. Response surface methodology (RSM) and artificial neural network with generalized neural network (GNN) technique were used to optimize the maximum bio-oil yield while considering temperature, heating rate, retention time, and argon gas flow rate as independent variables and bio-oil production as the response. Typical neural networks have constraints such as a long training time, a large number of neurons, and a large number of hidden layers. A generalized neural network (GNN) has been constructed to address these limitations and build a non-linear controller for acquiring access to bio-oil production output. To anticipate bio-oil yield, a new prediction model is proposed that combines the benefits of an auto-adaptive management technique with the rapid reaction of a GNN. Three measures (MSE, RMSE, and R2) are explored in depth to assess the performance efficacy of the models. Based on the finding, 350 °C temperature, 125 min of retention time, 120 °C/min heating rate and 110 mL/min argon flow rate was used to produce the highest bio-oil production (38.43%). Based on techniques, both models used in the study produce equally acceptable outcomes for projecting bio-oil yield. The greatest R2 value for the bio-oil yield ranges from 0.94 to 0.99, and all outcomes are classified as "good" regarding RMSE (all RMSE values are close to one). When all indicators are combined, GNN provides superior accuracy in predicting bio-oil yield in this investigation, followed by ANN. [Display omitted] • Production of bio-oil from lychee-based biomass and maximization by statistical and soft computing techniques. • Temperature, heating rate, retention time and argon flow rate are independent variables and bio-oil production is the response. • 350 °C temperature, 125 min of retention time, 120 °C/min heating rate and 110 mL/min argon flow rate was the optimum condition. • Around 38.43% of bio-oil was produced with chemical compounds making it suitable for various industrial applications. [ABSTRACT FROM AUTHOR]