Evaluation of Oil Palm Biomass Potential for Bio-oil Production via Pyrolysis Processes

The yield and quality of bio-oil obtained from pyrolysis processes depends on many factors, including pyrolysis types, reactor types, operating conditions and biomass property. The objective of this work was therefore to evaluate the potential of oil palm biomass, including oil palm trunk (OPT), oil palm fronds (OPF), oil palm decanter (DC) and oil palm root (OPR) for producing bio-oil via pyrolysis processes. The potential of oil palm biomass was considered in terms of proximate analysis, ultimate analysis, heating value, equivalent heating value, Thermogravimetric analyser (TGA) and lignocellulose content. The results showed that the moisture content of fried samples was in the range of 7.5-10.7% (w.b), which was relatively low and appropriate for pyrolysis. The volatile content of OPT and OPF was higher than 72% (wt.). The carbon, oxygen and hydrogen content of oil palm samples were in the range of 41.5-45.6, 30.7-40.2 and 5.7-5.9% (wt.), respectively. The higher heating value (HHV) of samples was relatively low compared to the HHV of fossil fuels. The OPT and OPF had high cellulose and hemicellulose content, while provided low lignin content compared to the lignin content of DC and OPR. The TGA results showed that thermal decomposition of samples took place within the range of 200–450 °C, which the lignin content affected the thermal decomposition trend. These results revealed that the selected oil palm biomass had relatively high potential for producing bio-oil via pyrolysis processes, particularly the OPT and OPF

Experimental and numerical investigations of Underground Coal Gasification (UCG) using half-teardrop shape cavity

In this work, the process of Underground Coal Gasification (UCG) was studied experimentally and numerically. The typical cavity of UCG was a half-teardrop shape. Thecoal samples were collected from Mae Moh coal mine, Thailand. The coal type is mainly lignite. To generate the gasification process, the coal sample was heated in the half-teardrop cavity by injecting partial oxidant, which is air, according to the Equivalent Ratio (ER) of 0.1, 0.2, 0.3, 0.5, and 0.7. The properties of the product gas were measured using a syngas analyser. CFD technique, ANSYS (Fluent), was used to simulate flow characteristics and gasification process in the cavity. The experimental results show that the low heating value (LHV) of syngas peaks at 0.92 MJ/m3 when ER = 0.1, and LHV decreases monotonically as ER increases. The CFD results show that the area of high temperature in the UCG cavity is larger when the ER was great

Evaluation of Oil Palm Biomass Potential for Bio-oil Production via Pyrolysis Processes

The yield and quality of bio-oil obtained from pyrolysis processes depends on many factors, including pyrolysis types, reactor types, operating conditions and biomass property. The objective of this work was therefore to evaluate the potential of oil palm biomass, including oil palm trunk (OPT), oil palm fronds (OPF), oil palm decanter (DC) and oil palm root (OPR) for producing bio-oil via pyrolysis processes. The potential of oil palm biomass was considered in terms of proximate analysis, ultimate analysis, heating value, equivalent heating value, Thermogravimetric analyser (TGA) and lignocellulose content. The results showed that the moisture content of fried samples was in the range of 7.5-10.7% (w.b), which was relatively low and appropriate for pyrolysis. The volatile content of OPT and OPF was higher than 72% (wt.). The carbon, oxygen and hydrogen content of oil palm samples were in the range of 41.5-45.6, 30.7-40.2 and 5.7-5.9% (wt.), respectively. The higher heating value (HHV) of samples was relatively low compared to the HHV of fossil fuels. The OPT and OPF had high cellulose and hemicellulose content, while provided low lignin content compared to the lignin content of DC and OPR. The TGA results showed that thermal decomposition of samples took place within the range of 200–450 °C, which the lignin content affected the thermal decomposition trend. These results revealed that the selected oil palm biomass had relatively high potential for producing bio-oil via pyrolysis processes, particularly the OPT and OPF

The Effect of Biomass Shapes on Combustion Characteristic in Updraft Chamber

The objective of this work was to study the effect of biomass shapes on combustion characteristic in an updraft chamber. 6 types of biomasses: rubber wood chips, coconut shell, oil palm empty fruit bunch, corn straw, rubber wood sawdust, and mixed palm cake that are agricultural wastes in Thailand were categorized by 3 shapes namely: chip shape, fiber shape, and powder shape. They were burnt using a combustion chamber, which was a simple type of direct combustion. The diameter of combustion chamber was 20 cm and the total height of the combustion chamber was 160 cm. Biomass sample, which moisture content was lower than 20%, was fixed at 1 kg per experiment for burning. The air velocity was varied at 0.50, 0.75 and 1.00 m/s which corresponds to an equivalence ratio between 1 up to 3.5. The temperature at different positions along combustion chamber height and the properties of product gas (carbon monoxide) were measured. The experimental results show that the biomass shape influences the combustion process. The fiber shape has low combustion temperature and higher carbon monoxide, which is indicated improper combustion. The chip shape was well burnt with higher air velocity and the product gas has the lowest amount of carbon monoxide. In addition, it had lower temperature than powder shapes. As for the powder shapes, it shows suitability for combustion with an updraft combustion chamber because it has the highest temperature compared with other types of biomass. However, it has some limitation for some powder biomass types as sawdust. When the air velocity was high, there was carryover of biomass particles without burning

Experimental and Numerical Investigations of Underground Coal Gasification (UCG) Using Half-teardrop Shape Cavity

In this work, the process of Underground Coal Gasification (UCG) was studied experimentally and numerically. The typical cavity of UCG was a half-teardrop shape. The coal samples were collected from Mae Moh coal mine, Thailand. The coal type is mainly lignite. To generate the gasification process, the coal sample was heated in the half-teardrop cavity by injecting partial oxidant, which is air, according to the Equivalent Ratio (ER) of 0.1, 0.2, 0.3, 0.5, and 0.7. The properties of the product gas were measured using a syngas analyser. CFD technique, ANSYS (Fluent), was used to simulate flow characteristics and gasification process in the cavity. The experimental results show that the low heating value (LHV) of syngas peaks at 0.92 MJ/m3 when ER = 0.1, and LHV decreases monotonically as ER increases. The CFD results show that the area of high temperature in the UCG cavity is larger when the ER was greater

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

Syngas production from rubberwood biomass in downdraft gasifier combined with wet scrubbing: investigation of tar and solid residue

Production of synthesis gas by gasification is still a challenge due to the tar in the synthesis gas (syngas). This tar needs to be eliminated by appropriate methods before using the syngas as a fuel. Moreover, the solid residue after gasification also needs to be properly managed or destroyed. Therefore, the aim of this study was to investigate tar and solid residue generated by gasification of rubberwood biomass, including rubberwood chips (RWC), rubberwood pellets (RWP), rubberwood unburned char (UBC), and their blends, in a downdraft gasifier. Waste vegetable oil (WVO) and water were used as scrubbing media. Properties of the biomass samples were characterized by proximate and ultimate analysis, as well as for the higher heating value. The downdraft gasifier was operated at 850 °C and equivalence ratio (ER) of 0.25. The concentrations of tar in syngas both before and after passing through the wet scrubber were determined. Chemical compounds in the tar were analysed by GC-MS. The solid residue remaining after gasification was separated into biochar and ash. The biochar was characterized by CHNS/O analyser, FTIR, SEM, and for the iodine number. The compounds in ash were determined by XRF. The results show that biomass type and scrubbing media affected the tar removal efficiency. Scrubbing syngas with WVO had better tar removal efficiency than scrubbing with water. The highest tar removal efficiency with WVO was 82.16%. The tar sample consisted of complex compounds as indicated by GC-MS, and these compounds depended on type of biomass feedstock. The solid residue obtained after gasification process contained biochar (unburned carbon) and ash. Some biochars can be used as solid fuels, depending on carbon content and energy content. The biochar also had a highly porous structure based on SEM imaging, and a high iodine number (930-1134 mg/g). The biochar contained the functional groups OH, C-O, and C-H, as indicated by FTIR. CaO, K2 O, SiO2 , and MgO were the major components in ash. The spent WVO, biochar, and ash need to be properly managed or utilized for sustainable gasification operations, and these results support that pursuit

Assessment of Suitable Areas for Smart Grid of Power Generated from Renewable Energy Resources in Western Uganda

This study assessed suitable smart grid areas for power generation and distribution from solar and small hydro energy resources in Western Uganda by employing the fuzzy analytic hierarchy process (AHP) based on geographic information system (GIS) data. This was performed based on the selected economic, environmental, and technical criteria by the authors guided by the experts’ judgements in the weighing process. The main criteria also included various sub-criteria. The sub-criteria of the economic criterion included distance from transmission lines, topography, and distance to roads. The environmental sub-criteria covered land use, sensitive areas, and protected areas. The technical sub-criteria were on distance from demand centers, available potential energy resources (solar and hydro), and climate (rainfall and sunshine). The weights of the main criteria and the sub-criteria were calculated by using the fuzzy AHP. These weights were then used in the GIS environment to determine both the potential for power generation from the solar energy resource and the smart grid suitable areas. According to the weight results, the economic criteria has the highest weight, followed by environmental and technical criteria. The validation of the experts’ judgements for each criterion by comparing the results from fuzzy AHP with AHP confirmed insignificant differences in weights for all criteria. The obtained suitable smart grid areas in Western Uganda have been classified into three parts, that is, the South, North, and Central. Therefore, this is a one-of-a-kind study that, in the authors’ view, will provide the initial insights to the government, policymakers, renewable energy practitioners, and researchers to investigate, map, and embrace decarbonization strategies for the electricity sector of Uganda

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

The effect of Biomass Shapes on combustion characteristic in updraft chamber

The objective of this work was to study the effect of biomass shapes on combustion characteristic in an updraft chamber. 6 types of biomasses: rubber wood chips, coconut shell, oil palm empty fruit bunch, corn straw, rubber wood sawdust, and mixed palm cake that are agricultural wastes in Thailand were categorized by 3 shapes namely: chip shape, fiber shape, and powder shape. They were burnt using a combustion chamber, which was a simple type of direct combustion. The diameter of combustion chamber was 20 cm and the total height of the combustion chamber was 160 cm. Biomass sample, which moisture content was lower than 20%, was fixed at 1 kg per experiment for burning. The air velocity was varied at 0.50, 0.75 and 1.00 m/s which corresponds to an equivalence ratio between 1 up to 3.5. The temperature at different positions along combustion chamber height and the properties of product gas (carbon monoxide) were measured. The experimental results show that the biomass shape influences the combustion process. The fiber shape has low combustion temperature and higher carbon monoxide, which is indicated improper combustion. The chip shape was well burnt with higher air velocity and the product gas has the lowest amount of carbon monoxide. In addition, it had lower temperature than powder shapes. As for the powder shapes, it shows suitability for combustion with an updraft combustion chamber because it has the highest temperature compared with other types of biomass. However, it has some limitation for some powder biomass types as sawdust. When the air velocity was high, there was carryover of biomass particles without burning