Rubber Wood Sawdust Research Articles

Characteristics of Biochars Derived from the Pyrolysis and Co-Pyrolysis of Rubberwood Sawdust and Sewage Sludge for Further Applications

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.

Study of Lignin Extracted from Rubberwood Using Microwave Assisted Technology for Fuel Additive.

Lignin is the most abundant natural aromatic polymer, especially in plant biomass. Lignin-derived phenolic compounds can be processed into high-value liquid fuel. This study aimed to determine the yield of lignin by the microwave-assisted solvent extraction method and to characterize some essential properties of the extracted lignin. Rubberwood sawdust (Hevea brasiliensis) was extracted for lignin with an organic-based solvent, either ethanol or isopropanol, in a microwave oven operating at 2450 MHz. Two levels of power of microwave, 100 W and 200 W, were tested as well as five extraction times (5, 10, 15, 20, 25, and 30 min). The extracted lignin was characterized by Klason lignin, Fourier transform infrared spectroscopy (FT-IR), 2D HSQC NMR, Ultraviolet-visible spectrophotometry (UV-vis), and Bomb calorimeter. The results showed that the yield of extracted lignin increased with the extraction time and power of the microwave. In addition, the extraction yield with ethanol was higher than the yield with isopropanol. The highest yield was 6.26 wt.%, with ethanol, 30 min extraction time, and 200 W microwave power.

Bio-Phenolic Resin Derived Porous Carbon Materials for High-Performance Lithium-Ion Capacitor.

In this article, hierarchical porous carbon (HPC) with high surface area of 1604.9 m2/g is prepared by the pyrolysis of rubberwood sawdust using CaCO3 as a hard template. The bio-oil pyrolyzed from the rubber sawdust, followed by the polymerization reaction to form resole phenolic resin, can be used as a carbon source to prepare HPC. The biomass-derived HPC shows a three-dimensionally interconnected morphology which can offer a continuous pathway for ionic transport. The symmetrical supercapacitors based on the as-prepared HPC were tested in 1.0 M tetraethylammonium tetrafluoroborate/propylene carbonate electrolyte. The results of electrochemical analysis show that the HPC-based supercapacitor exhibits a high specific capacitance of 113.3 F/g at 0.5 A/g with superior rate capability and cycling stability up to 5000 cycles. Hybrid lithium-ion capacitors (LICs) based on the HPC and Li4Ti5O12 (LTO) were also fabricated. The LICs have a maximum energy density of 113.3 Wh/kg at a power density of 281 W/kg. Moreover, the LIC also displays a remarkable cycling performance with a retention of 92.8% after 3000 cycles at a large current density of 0.75 A/g, suggesting great potential application in the energy storage of the LIC.

Optimization of Organic Mulches Thickness Improves Soil Moisture Retention under Controlled Conditions

Organic mulch can improve the moisture, chemical composition, dust, and dust suppression of soil, and beautify the environment. In view of the rapid evaporation rate and serious loss of soil water in tropical areas, this paper explored the effect of organic mulch materials with different thickness on the increase of soil water retention rate and the improvement of soil water loss caused by evaporation. Rubberwood sawdust (RWS), rubberwood bark (RWB), coconut fiber (CF), and Mulch (MC) were selected as the mulching materials. Field experiment and laboratory experiment were performed, and soil-moisture content and temperature were continuously monitored. However, from the daily measurement of water content at constant conditions (29°C ± 0.2°C, 74% ± 1% air RH) in the laboratory experiment, the results of variance analysis (ANOVA) showed that there was no significant difference between the soil-water content of covered samples and bare soil (P > 0.05). In the field experiments, the analysis of variance indicated significant differences in the soil-moisture content owing to the effect of the covering material (P

Ultrahigh-surface-area activated biocarbon based on biomass residue as a supercapacitor electrode material: Tuning pore structure using alkalis with different atom sizes

This work aims to develop an electrode material based on activated biocarbon made from rubber wood sawdust waste using alkali activating agents – KOH, NaOH, and LiOH – via a solvent-free mechanical mixing. The role of different alkali metal atom sizes plays in resulting pore structure has been studied for the first time. The influence of standard reduction potentials on the pore structure and electrochemical performance of the activated biocarbon are also investigated. The biocarbons activated with KOH or NaOH exhibit a microporous characteristic and a wide range of specific surface area of 1323–3040 m2/g, while the one activated with LiOH exhibits a mesoporous nature. The comparatively small atom size of Li and its low standard reduction potential may have caused the slow reactivity of LiOH with carbon matrix. This leads to the low specific surface area of 1134 m2/g and the formation of tiny lithium particles that could intercalate into biocarbon structure more readily than potassium or sodium particles. Mesoporosity tends to be generated by using alkali activating agent with small metal atom size and low standard reduction potential, whereas microporosity has an opposite trend. Cyclic voltammetry curves and charge-discharge profiles confirm the dominant EDLC behavior along with partial pseudocapacitance for activated biocarbons. The maximum specific capacitance is 195.3 F/g at 0.25 A/g for biocarbon activated with KOH at 4:1. This value is reduced to 69.4% of its original values at 4 A/g. The biocarbons activated with LiOH or NaOH retain the rate capability by 82.9% and 80.4%, respectively.

Influence of extraction solvents on the recovery yields and properties of bio-oils from woody biomass liquefaction in sub-critical water, ethanol or water–ethanol mixed solvent

In this work, the effects of extraction solvents: acetone, ethanol, dichloromethane (DCM) and ethyl acetate (EA), on the yields and characteristics of bio-oil products obtained from liquefaction of rubberwood sawdust (RS) at 300 ℃ for 30 min in water, ethanol or water–ethanol mixed solvent (50/50, v/v) were comparatively studied. When pure water or ethanol was used as the reaction medium, the highest bio-oil yield was obtained by acetone (30.41 wt%) or EA (31.69 wt%), respectively. Besides, significantly higher bio-oil yields were observed in RS liquefaction in water–ethanol mixed solvent with the maximum bio-oil yield of 56.67 wt% obtained by acetone. But ethanol was always the least efficient in recovering bio-oil in all cases. Besides, the elemental analysis showed that DCM was conducive to recover the bio-oil products with lower oxygen contents and the higher HHVs, while the acetone-extracted bio-oils were worse in quality. However, the highest carbon recovery (CR) and energy recovery (ER) were obtained by acetone due to its higher bio-oil yield produced in water–ethanol mixed solvent. As suggested by GC–MS, GPC and TGA analysis, the extraction solvents and reaction mediums both greatly affected the chemical compositions of the bio-oil products. Phenols were dominant in bio-oil products, followed by hydrocarbons, ketones, esters, etc. Acetone tended to extract the bio-oil with larger carbon numbers and molecular weights, which might explain its higher bio-oil recovery yield in water or water–ethanol mixed solvent. DCM was beneficial to recover the bio-oil was more light compounds with smaller molecular weights and lower boiling point distribution. But for the liquefaction in pure ethanol, more similar chemical compositions were observed among different samples when compared to the cases in other reaction mediums.

Valorization of rubberwood sawdust and sewage sludge by pyrolysis and co-pyrolysis using agitated bed reactor for producing biofuel or value-added products.

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.

Synthesis and characterization of activated carbon derived from rubberwood sawdust by using KOH/KMnO4 as multiple function activation agents

This research is focused on the effects of impregnation ratios using KOH/KMnO4 as multiple function activation agents on microporous of activated carbon. Rubberwood sawdust, the waste from wood processing industry, was used as a raw material in synthesis of activated carbon by chemical activation. The rubberwood sawdust was carbonized at 400 °C for 1 hour under an inert atmosphere to produce char. Chars were impregnated with different proportions of KOH and KMnO4. Impregnation time for each mixture proportion (Char: KOH: KMnO4) was 24 hours before activation for 3 hours at 800 °C. The surface area, pore volume, micropore volume, pore size distribution, porous structure, and adsorption isotherm were examined and considered as the properties of activated carbon. The results showed that the activated carbon with an impregnation ratio of 10:10:5, 10:30:0, and 10:30:5 have the surface area 750.89 m 2/g, 1574.39 m 2/g, and 1346.10 m 2/g, respectively. The pore volume and micropore volume were in the range between 0.3289-0.6405 cm 3/g and 0.1920-0.3533 cm 3/g. The average pore sizes were 1.75 nm, 1.63 nm, and 1.65 nm, respectively. These synthesized activated carbons were characterized as type I isotherm and microporous solids.

Natural cellulosic material characteristics: A possibility to develop antimicrobial active fiber-based packaging

Coconut husk, rubberwood sawdust, and palm leaf base are cellulosic agricultural wastes that have potential to be processed to fiber as absorbing material. This study investigated characteristics (morphological, physiological properties, chemical composition, absorption capacity, and water absorption isotherms) of coconut, rubberwood, and palm fiber. Also, the study aimed to develop an antimicrobial sachet packaging to resist against foodborne pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli) by adding lime oil (LO) emulsion or Litsea cubeba (LC) oil at 50 to 700 µL into the material (1 g) before, and then dried and placed in the 1-L seal box. Results showed that among the three, coconut performed the best in terms of releasing the essential oil (EO) emulsion against bacteria. Coconut could adsorb and release volatile LO or LC at the lowest concentrations (LO, 500 µL/L; LC, 300 µL/L) to inhibit bacteria compared with the other fibers (700 µL/L) at 35 °C. Results indicated that coconut has a low water absorption rate, which influenced the faster adsorption of EO emulsion in the beginning of the process; therefore, using low concentrations of EO in coconut for bacterial inhibition is possible. Coconut contains 34.5% lignin, 68.7% holocellulose, 37.6% cellulose, and 31.2% hemicellulose. Coconut is suitable as an alternative to the biocomposite material in developing a new antimicrobial packaging design.

Physicochemical Characterisation and the Prospects of Biofuel Production from Rubberwood Sawdust and Sewage Sludge

This study aims to evaluate the physicochemical properties of rubberwood sawdust (RWS) and sewage sludge (SS) for producing biofuel or liquid products via pyrolysis and co-pyrolysis. The chemical and thermal properties of both samples were observed to have superior bioenergy production capabilities. RWS and SS had significantly different physicochemical properties, such as particle-size distribution, bulk density, ultimate and proximate analysis, lignocellulose composition, thermal-degradation behaviour, and major and minor elements. The composition of extractives was found to only marginally affect the end product. Carbon and hydrogen content, the two main elements for biofuel enhancement, were found to correlate with the organic components of both RWS (48.49, 7.15 wt.%) and SS (32.29, 4.06 wt.%). SS had a higher elemental composition of iron, calcium, and potassium than RWS. Both samples had a higher heating value of 13.98 to 21.01 MJ/kg and a lower heating value of 11.65 to 17.66 MJ/kg, a lesser energy potential than that of fossil fuels. The findings from these blends are relatively moderate due to the related lignocellulosic potential composition. The novel contribution of this research was to optimize the use of local waste materials as a new raw material for biofuel production that could serve as a sustainable fuel source.

The Effect of Biomass Shapes on Combustion Characteristic in Updraft Chamber

Combustion of agricultural residues and wastes for energy applications is still popular. However, combustion of biomass with different shapes leads to many side effects such as agglomeration, emission and incomplete combustion. The aim of this study was therefore to investigate the effects of biomass shapes on combustion characteristics in an updraft combustion chamber. The rubber wood chip, coconut shell, oil palm empty fruit bunch, corn straw, rubber wood sawdust, and mixed palm cake were used as fuel and they were categorized as 3 shapes namely, chip shape, fiber shape, and powder shape. The biomass sample was combusted in simple cylindrical shape combustion chamber. The diameter of combustion chamber was 20 cm and its height was 160 cm. The biomass sample (moisture content below 20%) with amount of 1 kg was used to perform the experiment. The ambient air that had velocity of 0.50, 0.75 and 1.00 m/s (corresponding to an equivalence ratio of 1-3.5) was supplied to combustion chamber. The temperature at different positions along combustion chamber height and the properties of flue gases (carbon monoxide) were then measured. The results showed that the biomass shape had effect on combustion characteristics. Combustion of fiber shape biomass led to low combustion temperature, while the carbon monoxide in flue gases was high. This indicates the improper combustion process. The chip shape biomass was well combusted at a higher air velocity and the flue gases had lowest carbon monoxide. The highest combustion temperature was obtained from combustion of powder shape biomass. However, it led to the problem of unburned biomass such in case of sawdust. This is because the sawdust powder was carried from combustion chamber before burning completely.

Bioethanol production from forest residues and life cycle cost analysis of bioethanol-gasoline blend on transportation sector

In this study, an experimental investigation of pure bioethanol production from the waste biomass of the most significant cultivated feedstock (oil palm and rubber-wood) in Malaysia and life cycle cost analysis of bioethanol-gasoline blend on Malaysian transportation sector has been demonstrated. The experimental investigations presented all the stages from oil palm frond/leaves and rubber-wood sawdust collection to bioethanol purification. Both feedstocks have been pre-treated by sulfuric acid and sodium hydroxide, hydrolyzed by cellulase enzyme, and fermented by Saccharomyces cerevisiae within 12–72 h to produce bioethanol. After distillation, 35% and 45% pure bioethanol was obtained for mixed oil palm residues and rubber-wood sawdust, respectively. Detailed life cycle cost analysis of a large-scale bioethanol plant (20 ktonns/y) has been designed based on the experimental outcome for 20 years life time. The possibility of 5% (E5) and 10% (E10) replacement of total gasoline application for Malaysian transportation sector by the produced bioethanol has been simulated using simulation software code blocks. From the economic perspective, the results presented that both waste biomass can be converted into a value-added product, bioethanol, and a by-product, biomass content that can add market value as commercial biofertilizer. This study suggested that partial substitution of gasoline with bioethanol produced from forest residues could lead to the significant commercial aspect of fuel savings for the transportation sector in Malaysia.

Making blends of agarwood waste with empty palm bunches or rubber wood sawdust for pelletized biofuels

This study created biomass-pellet fuel with reduced ash content from agarwood waste mixed with empty palm bunches (ACW+EPB), and from agarwood waste with rubber wood sawdust (ACW+RWS), utilizing the low ash value of the agarwood waste. The tested blends had a 1:1 ratio of agarwood waste and empty palm bunches, and a 1:3 ratio of agarwood waste and rubber wood sawdust. Comparisons were also conducted relative to Korean (Grade 4) (2014) and ENplus B (2014) commercial pellet standards. Before pressure molding, the mixture components were dried and ground in a pelletizing device with a motor power of 7.5 kW (380 V, 50 Hz), yielding 100 to 150 kg/h without added adhesive. The test results showed that ACW ash content decreased in the RWS hybrid, yet increased in the EPB mixture. The attributes of ash content, moisture content, and heating value of ACW+RWS satisfied ENplus B (2014) and Korean (Grade 4) (2014) standards at 1.70%, 4.50%, and 4,536 kcal/kg. The ACW+EPB also satisfied the Korean (Grade 4) standard at 4.20%, 6.50%, and 4,220 kcal/kg. Thus, the biomass pellets from the mixture of agarwood waste and rubber wood sawdust and that of agarwood waste and empty palm bunches were of suitable quality for commercial purposes.

Comparative Investigation of Yield and Quality of Bio-Oil and Biochar from Pyrolysis of Woody and Non-Woody Biomasses

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.

Enhancing the fuel properties of rubberwood biomass by moving bed torrefaction process for further applications

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.

Sound absorption properties of rigid polyurethane foam composites with rubber-wood sawdust as a natural filler

Rigid closed-cell polyurethane (PU) foam is well-known for its ability to withstand external force. On the other hand, due to the closed-cell nature, its ability to absorb sound is doubtful since hollowed materials are supposed be better in sound absorption. However, the composites fabrication with non-reactive fillers was thought to improve sound absorption ability since it might prohibit the formation of closed cell in the process. In this research, rigid polyurethane foam was prepared from polyether polyol and polymeric methylene di-isocyanate (p-MDI) formulated with water as a blowing agent. Natural rubber-wood sawdust was used as a filler. The percentages of rubber-wood sawdust in the polyurethane foam composites were varied by 0, 1, 3, 5 and 7%. The measurement of sound absorption coefficient has been done using impedance tube technique. The results showed that the rigid closed-cell polyurethane foam with 0% filler exhibits poor acoustic absorption. Additionally, sound absorption coefficient results showed that a sample with higher amount of rubber-wood sawdust allowed the sound wave to be absorbed at wider frequency range. This could be explained that the rubber-wood sawdust filler played an important role in sound absorption property.

Adsorption of Remazol Brilliant Violet 5R dye from aqueous solution onto melunak and rubberwood sawdust based activated carbon: interaction mechanism, isotherm, kinetic and thermodynamic properties

Adsorption of Remazol Brilliant Violet 5R dye from aqueous solution onto melunak and rubberwood sawdust based activated carbon: interaction mechanism, isotherm, kinetic and thermodynamic properties

Characteristics of pyrolysis products from pyrolysis and co-pyrolysis of rubber wood and oil palm trunk biomass for biofuel and value-added applications

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, CO2, H2 and CH4, 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.

Structural, Thermal, and Mechanical Properties of Spent Mushroom Substrate (SMS) and Rubberwood Sawdust (RWS) Binderless Particleboards

Structural, Thermal, and Mechanical Properties of Spent Mushroom Substrate (SMS) and Rubberwood Sawdust (RWS) Binderless Particleboards

Evaluation of various lignocellulosic biomass and cereal grains as potential spawn materials for wild Schizophyllum commune cultivation

Rapid mycelium growth in spawn production and on growth substrate could suppress contamination, which is significant in mushroom industry. The aim of the study is to investigate the potential of lignocellulosic biomass waste as new materials alternative to common cereal grains in producing spawn for wild S. commune cultivation on rice husk, paddy straw, and rubber wood sawdust. The fastest mycelium growth among lignocellulosic biomass was found on rice husk spawn (1.27 cm/day) and 1.98 cm/day for wheat grain. The shortest duration for substrate colonization for both lignocellulosic and grain spawn is on paddy straw, followed by rice husk, and rubber wood sawdust.