水熱法による農業廃棄物からの付加価値製品の研究

The oil palm industry\u27s steady growth over the past decade has resulted in the increasing production of waste solid and liquid biomass such as oil palm frond (OPF) and palm oil mill effluent (POME). Current disposal practices are not environmentally friendly and undermine the vast potential of biomass as a renewable resource. Due to this problem, research regarding the utilization and valorization of oil palm biomass as raw material for the production of value-added products has gained interest. Many new methods and processes to treat biomass and produce materials such as cellulose-based materials, biochar, activated carbon, and biofuels have been reported, but adoption by the industry has been lackluster. There has been a figurative wall that inhibits implementation and adoption, far beyond bench and pilot scale. Among the factors that inhibit adoption include complicated processes that require specialized equipment and chemicals, multiple pretreatment steps that increase the time required, and waste that needs to be disposed of, besides related increased cost to the industry. The research community must develop simpler, appropriate technology in utilizing oil palm biomass that can be easily adopted by the industry. This study presents several methods to try to solve the problems stated above. By utilizing the hydrothermal process, biomass (oil palm frond) and its derivative (oil palm empty fruit bunch biochar) were treated using nitric acid as oxidizing agent to remove lignin and in the case of biochar, to improve its performance via additional surface functional groups. For the hydrothermal lignin removal process, treated oil palm frond (OPF) lignin content decreased by 86.5% after 30 min of treatment at 120°C. Cellulose yield was 68.2% which is comparable to other previously reported literature. Further analysis using TGA, FTIR, and XRD concluded that hydrothermally treated OPF has similar thermal stability, surface chemical property, and crystallinity to commercially available cellulose products (microcrystalline cellulose). The process was also applied to oil palm empty fruit bunch (OPEFB) and Matake bamboo without any modification and pretreatment. Both biomass shows similar lignin reduction and properties such as treated OPF which showed that the process can be applied to other types of biomass without significant parameter modification. Hydrothermally treated biomass still showed a significant amount of hemicellulose which can be problematic especially in the production of cellulose-based composites and fibers. Removal of hemicellulose via superheated steam (SHS) treatment is proposed due to the excellent hemicellulose removal efficiency reported in the literature. It was found that the process produced biomass that can dissolve in sodium hydroxide (NaOH) solution at room temperature. This property was novel since the dissolution of cellulose in alkali solution usually requires additives such as urea and thiourea, and sub-zero temperature. NaOH-soluble biomass was analyzed via TGA, FTIR, and XRD which showed similar physical and chemical characteristics as normal cellulose fiber (MCC). 13C cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy analysis suggested that the reduction in intra-chain and inter-sheet hydrogen bonding strength is the contributing factor in the increased solubility of cellulose after SHS treatment. Besides direct biomass treatment, the hydrothermal process was also applied to biochar from oil palm biomass (OPEFB) to improve its performance in adsorbing dye and heavy metals. The process successfully increased the amount of surface functional groups without significant change in the surface morphology based on SEM, BET surface area, FTIR, and EDX analysis. Adsorption isotherm experiments suggested that the adsorption process occurred following the Langmuir isotherm model and pseudo-second-order kinetic model. Intra-particle diffusion model analysis suggested multiple stages of adsorption. Adsorption performance of functionalized biochar in removing dye and heavy metal from aqueous solution showed improved performance, with almost 7x increase in methylene blue adsorption capacity, and up to 6x increase in removal percentage for heavy metal adsorption. This result suggested that biochar performance can be improved through functionalization, and the process can be done using the hydrothermal method. The results presented in this thesis provide new methods and processes that can be easily implemented in the industry due to its simplicity, lower usage of chemicals, and utilizing available resources in the palm oil mill industry such as hydrothermal treatment (fresh fruit bunch sterilizer) and steam from the boiler. This result can help promotes better technology for the oil palm industry.九州工業大学博士学位論文 学位記番号：生工博甲第416号 学位授与年月日：令和3年9月24日1 Introduction|2 Literature Review|3 Hydrothermal Lignin Removal from Oil Palm Biomass|4 Combined Hydrothermal and Superheated Steam (SHS) Treatment on Biomass|5 Hydrothermal Surface Functionalization of Oil Palm Biochar and Other Carbon Material|6 Conclusion and Recommendations九州工業大学令和3年

Hydrothermal Functionalization of Oil Palm Empty Fruit Bunch Biochar for Wastewater Treatment Purposes

The use of biochar as an adsorbent for wastewater treatment purposes has been hindered due to its lower surface area compared to activated carbon. Current research on increasing surface functional groups on biochar surfaces to improve its adsorption performance suggests using high chemical concentration and long period of modification. This study solves these problems by focusing on improving surface functionalities of biochar via the hydrothermal functionalization process. Oil palm empty fruit bunch biochar was functionalized using autoclave with nitric acid as the functionalization agent. Functionalized biochar properties such as Brunauer–Emmett–Teller (BET) surface area and surface functional groups were analyzed and compared with untreated biochar. Fourier Transform Infrared (FTIR) spectroscopic analysis shows a significant increase in absorption by oxygen functional groups and is corroborated with energy dispersive X-ray (EDX) analysis. The process does not result in any major change in surface morphology and reduction in surface area value. Methylene blue (MB) adsorption test shows 7 times increase in adsorption performance. These results show that the simple hydrothermal functionalization process successfully functionalizes the biochar surface and improves its performance without affecting its surface area at lower concentration, and shorter time compared to previous studies. This result, with future large-scale experimentation using real-life equipment in palm oil mills, would provide a better technology that can be implemented in the industry

Production of biochar with high mineral content from oil palm biomass

Carbonization of oil palm empty fruit bunch (OPEFB) biomass for the production of high mineral content biochar under an uncontrolled carbonization temperature and controlled air flow rate was studied using a pilot-scale brick carbonization reactor. The maximum temperature during the carbonization process was found to be in the range of 543 to 564 oC at exhaust gas flow rate of 36 m3/hr. All minerals (i.e P, K ,Mg, Ca, Na, Mn, Fe, Cr, AI) showed an increased from the feedstock concentration up to 300 %. The concentration of heavy metal extracted from OPEFB biochar was lower than listed ceiling permitted levels. This proposed system without electrical control and heating source is preferable to the industry due to its simplicity, ease of operation and low energy requirement making it suitable for OPEFB biochar production for mulching purposes with more than double the mineral content compared to raw OPEFB biomass

Social Capital and Slum Communities: How to Fulfill Their Basic Needs in Palembang City during The Covid-19 Pandemic

The problem of slum settlements is still a major problem faced in Indonesia and other developing countries. One of the triggers for the emergence of slum settlements is due to the high rate of population growth, both through the birth process and the urbanization process. This study discusses the social capital of the people of the slum area of Palembang City in fulfilling basic needs, precisely in the 12 Ulu Village Area, Palembang City during the Covid-19 pandemic. This research uses a qualitative approach with a descriptive method. Sampling used a purposive sampling method with data collection using observation techniques and in-depth interviews. The study's findings indicate that (1) a high level of social capital as measured by networks, norms, and beliefs enables slum communities to survive the COVID-19 pandemic, and (2) the slum area communities' strategy for survival is to utilize yard land, home industries, social gathering, recitation, and mutual cooperation. There are several policy implications from this research: (1) Strengthen social capital, (2) Enhance community engagement, (3) Targeted support for vulnerable groups, (4) Ensure food security and (5) Strengthen social safety nets.

Successful scaling-up of self-sustained pyrolysis of oil palm biomass under pool-type reactor

An appropriate technology for waste utilisation, especially for a large amount of abundant pressed-shredded oil palm empty fruit bunch (OFEFB), is important for the oil palm industry. Self-sustained pyrolysis, whereby oil palm biomass was combusted by itself to provide the heat for pyrolysis without an electrical heater, is more preferable owing to its simplicity, ease of operation and low energy requirement. In this study, biochar production under self-sustained pyrolysis of oil palm biomass in the form of oil palm empty fruit bunch was tested in a 3-t large-scale pool-type reactor. During the pyrolysis process, the biomass was loaded layer by layer when the smoke appeared on the top, to minimise the entrance of oxygen. This method had significantly increased the yield of biochar. In our previous report, we have tested on a 30-kg pilot-scale capacity under self-sustained pyrolysis and found that the higher heating value (HHV) obtained was 22.6–24.7 MJ kg−1 with a 23.5%−25.0% yield. In this scaled-up study, a 3-t large-scale procedure produced HHV of 22.0–24.3 MJ kg−1 with a 30%−34% yield based on a wet-weight basis. The maximum self-sustained pyrolysis temperature for the large-scale procedure can reach between 600 °C and 700 °C. We concluded that large-scale biochar production under self-sustained pyrolysis was successfully conducted owing to the comparable biochar produced, compared with medium-scale and other studies with an electrical heating element, making it an appropriate technology for waste utilisation, particularly for the oil palm industry

A holistic treatment system for palm oil mill effluent by incorporating the anaerobic-aerobic-wetland sequential system and a convective sludge dryer

An integrated treatment system which incorporated an anaerobic-aerobic-wetland sequential system (AAWSS) and a convective sludge dryer (CSD) was established to treat highly polluting palm oil mill effluent (POME) in a shorter retention period and with a smaller area requirement. Before actual treatment, a start-up operation was performed to achieve optimal degradation performance. The strategy involved a stepwise feeding from 0.2 to 1 m3 d−1 at three day intervals for 15 days. During the operation, the lowest hydraulic retention time of 21 days was achieved and the biogas production was gradually increased from 1442 to 11,028 kg d−1with the increase of organic loads from 0.46 to 2.2 kg m−3 d−1. COD, VSS and VFA were almost completely (99%) removed, whereas the average percentage removals of SS and TN were 96% and 72%, respectively. To demonstrate the plant’s robustness in treating POME, the AAWSS was proceeded with a 360 days operation. A slight deterioration in COD and SS removals were observed from day 225 to day 265 due to an organic shock load. One unanticipated finding was that the AAWSS regained its stability shortly thereafter thus ensuring consistency of the treatment performance for long-term use. Further treatment with CSD was designed to produce a clear effluent that surpassed the industrial effluent discharge limits at low-cost. By referring to mass balance, the production efficiency achieved 95% condensate yield, leaving 7% concentrate and 2% dewatered solids as byproducts

A one-step self-sustained low temperature carbonization of coconut shell biomass produced a high specific surface area biochar-derived nano-adsorbent

A one-step self-sustained carbonization of coconut shell biomass, carried out in a brick reactor at a relatively low temperature of 300–500°C, successfully produced a biochar-derived adsorbent with 308 m2/g surface area, 2 nm pore diameter, and 0.15 cm3/g total pore volume. The coconut shell biochar qualifies as a nano-adsorbent, supported by scanning electron microscope images, which showed well-developed nano-pores on the surface of the biochar structure, even though there was no separate activation process. This is the first report whereby coconut shell can be converted to biochar-derived nano-adsorbent at a low carbonization temperature, without the need of the activation process. This is superior to previous reports on biochar produced from oil palm empty fruit bunch

Activated carbon from oil palm mesocarp fiber for the treatment of final discharge of palm oil effluent

Malaysia palm oil industry produced abundant amounts of solid and liquid biomass annually. The current disposal practice is not environmentally friendly, with viable biomass for production of value added product being wasted. It is desirable to reuse the biomass as a feedstock for production of activated carbon and use it to treat palm oil mill final discharge to achieve zero emission system. This study aimed to reduce the COD and suspended solids content of palm oil mill final discharge using oil palm mesocarp fiber activated by steam and phosphoric acid. The oil palm mesocarp fiber activated carbon was successfully produced either using steam and phosphoric acid as activating agents in a two-step process at a temperature of 600°C for 30 minutes. The resulting activated carbon BET surface area was found to be 494 and 1090 m2/g, respectively, which are comparable to commercial activated carbon. The activated carbon also shows pore development compared to raw material from SEM analysis. Oil palm mesocarp fiber activated carbon was used to treat palm oil mill final discharge and the effect of adsorbent dosage, treatment time, adsorbate concentration and consecutive treatments was studied. The oil palm mesocarp fiber activated carbon were able to reduce the COD and suspended solids content of the final discharge with a COD percent removal of 70% and 42 % for phosphoric acid and steam activated mesocarp fiber at 10 g/L dosage, respectively. For suspended solids, the removal percent was 85% and 81%, respectively. The amount of pollutant reduced increased as the adsorbent dosage increase and remained constant after 10 g/L. In terms of treatment time, as the treatment time increased, the amount of pollutants that were removed increased until a certain amount of time, which was found to be 6 hours for both COD and suspended solids content. For adsorbate concentration, as the COD initial concentration increased, reduction of pollutants for phosphoric acid activated carbon maintained, while steam activated carbon shows a higher reduction at lower concentration. For suspended solids, a similar effect was observed. The effect of consecutive treatment was also studied, with the increasing number of treatments resulting in a higher total reduction of pollutants. Consecutive small dosage treatment also proves to be more efficient compared to a single large dosage treatment. It can be concluded that oil palm mesocarp fiber is a viable feedstock for activated carbon production, with resulting activated carbon able to reduce the pollutants in palm oil mill final discharge