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Hemp-Derived Hierarchical Porous Carbon with an Optimized Pore Structure by NaOH Activation for Supercapacitor Applications
(2025-11-11)
Bowornthommatadsana, Khemjiranee
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Klangvijit, Kanisorn
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Uwanno, Teerayut
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Phonyiem Reilly, Mayuree
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Yordsri, Visittapong
This study focuses on converting hemp hurd, a byproduct of hemp stalk processing, into high-performance activated carbon for supercapacitor applications. Hemp hurd was pyrolyzed and subsequently activated with NaOH at various ratios (biochar:NaOH = 1:1, 1:2, 1:3, 1:4). The Hurd-4 condition (1:4 ratio) yielded the highest specific surface area, 3033 m2/g. Our findings indicate that increasing the chemical activation ratio enhances the mesopore-to-micropore volume ratio (V<inf>meso</inf>/V<inf>micro</inf>) to 1.58 while maintaining a sufficient micropore volume for ion storage. This balanced pore structure effectively increased the specific capacitance, achieving a maximum of 725 F/g at a current density of 0.3 A/g in a 1 M H<inf>2</inf>SO<inf>4</inf>electrolyte. When assembled into a coin cell with an organic electrolyte, Hurd-4 exhibited a maximum specific capacitance of 39 F/g, a maximum energy density of 34 Wh/kg, and a power density of 395 W/kg, surpassing commercial activated carbon. Additionally, the device maintained 78% capacitance retention after 10,000 cycles at a current density of 0.5 A/g. The superior electrochemical properties are attributed to the largest specific surface area, highest pore volume, and optimal mesopore volume ratio. These results demonstrate the potential of hemp hurd as a highly efficient precursor for synthesizing activated carbon for high-performance supercapacitors.
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Highly active and stable Ni–W/SiO2 catalyst derived from W incorporated on Ni phyllosilicate for deoxygenation of triglycerides into green biofuel range hydrocarbons
(2025-10-01)
Praikaew, Wanichaya
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Prameswari, Jedy
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Ratchahat, Sakhon
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Chaiwat, Weerawut
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Sakdaronnarong, Chularat
Highly active and stable Ni–W/SiO<inf>2</inf> catalyst derived from W incorporated into Ni phyllosilicate (Ni-PS) was prepared by the ammonia evaporation (AE) method, and benchmarked with the catalyst prepared by the impregnation method (IM). Their catalytic activities were evaluated for deoxygenation of triglycerides into green biofuel-range hydrocarbons. The Ni-PS structure demonstrated a large surface area with strong interaction between Ni2+ and SiO<inf>2</inf>, resulting from the incorporation of Ni2+ into the silica framework, which led to highly dispersed Ni⁰ after H<inf>2</inf> reduction. Additionally, the H<inf>2</inf> adsorption and desorption capabilities, together with a substantial quantity of Lewis acid sites, were advantageous features of Ni-PS catalysts compared to Ni-IM and 5 W/Ni-IM catalysts. Ex situ and in situ structural characterizations revealed the generation of Ni⁰ and W⁰ states, along with remaining W4+ species after H<inf>2</inf> reduction. The 5 W/Ni-AE catalyst exhibited stable performance up to 60 h on stream, producing consistent yields of 30 % jet fuel and 40 % diesel, which was attributed to its high porosity, small Ni⁰ particle sizes, enhanced H<inf>2</inf> adsorption–desorption capacities, and abundant Lewis acid sites. Consequently, the heterogeneous 5 W/Ni-AE catalyst shows significant practical relevance for generating green biofuel from oil-derived feedstock in sustainable biorefineries.
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PRODUCTION OF TORREFIED BIOMASS PELLETS FROM WOODY AND AGRICULTURAL RESIDUES
(2023-01-01)
Inthapat, Pimonpan
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Boontanon, Suwanna Kitpati
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Prachakittikul, Pensiri
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Eiad-ua, Apiluck
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Jadsadajerm, Supachai
Two different combined process sequences of biomass pretreatment between pelletization after torrefaction (PAT) and pelletization before torrefaction (PBT) were comparatively investigated to produce torrefied biomass pellets (TBP) from woody biomasses, e.g. Leucaena (LC) and rubberwood (RW), and agricultural residues, e.g. rice straw (RS) and sugarcane leaves (SCL). In this study, each sample was thermally treated at 260-300°C for 5 min during torrefaction process. It was found that both woody biomasses and agricultural residues had mass yield lower than 63 wt%, while the bulk density of TBPs were improved higher than 400 kg/m3. For equilibrium moisture content (EMC) analysis, TBPs via PBT method had lower EMC than raw pellet after being kept at 30°C for 12 days. For the thermochemical properties, the TBPs had higher FC, %C, and HHVs than raw pellets in all biomass and increased with torrefaction temperature. When comparing the TBPs between PAT and PBT torrefied pellets, the HHVs of PBT torrefied pellets at 300°C were achieved highest at 27 MJ/kg (dry-ash-free, daf, basis) for SCL sample, which was considered as higher than the standard value at ≥21 MJ/kg of thermally treated biomass pellets (ISO/TS 17225-8:2016) and also in the range at 25.7-28.2 MJ/kg of coal. In addition, the combustion performance index (Sn) of PAT and PBT torrefied pellets was lower than raw pellets, showing a similar property as coal and lignite. Briefly, this study suggests using PBT pretreatment process to produce high quality solid fuel, particularly for agricultural residues such as SCL for a potential substitute of currently used coal.
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Simultaneous production of hydrogen and carbon nanotubes from biogas: On the design of combined process
(2022-04-15)
Rattanaamonkulchai, Raminda
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Kludpantanapan, Thunyathon
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Nantapong, Paveenuch
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Srifa, Atthapon
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Koo-Amornpattana, Wanida
We introduced a novel combined process of CO<inf>2</inf> methanation (METH) and catalytic decomposition of methane (CDM) for simultaneous production of hydrogen (H<inf>2</inf>) and carbon nanotubes (CNTs) from biogas. In this process, biogas is catalytically upgraded into CH<inf>4</inf>-rich gas in METH reactor using Ni/CeO<inf>2</inf> catalyst, and the obtained CH<inf>4</inf>-rich gas is subsequently decomposed into H<inf>2</inf> and CNTs in CDM reactor over CoMo/MgO catalyst. Among the three different process scenarios proposed, the combined process with a steam condenser equipped between METH and CDM reactors could greatly improve a CNTs productivity. The CNTs production yield increased by more than 2.5-fold, maximizing at 9.08 gCNTs/gCat with a CNTs purity of 90%. The deposited carbon product was characterized as multi-walled carbon nanotubes (MWCNTs) with a surface area of 136.0 m2/g, comparable with commercial CNTs of 199.8 m2/g. The remarkable I<inf>G</inf>/I<inf>D</inf> ratio of 2.18 confirms a superior portion of graphitic carbon in the synthesized CNTs upon the commercial CNTs with I<inf>G</inf>/I<inf>D</inf> = 0.74. Notably, the CH<inf>4</inf> conversion reached 94.5%, while the CO<inf>2</inf> conversion achieved 100%, resulting in the H<inf>2</inf> yield and H<inf>2</inf> purity higher than 90%. This combined process demonstrates a promising route for production of high quality CNTs and high purity H<inf>2</inf> with complete CO<inf>2</inf> conversion using biogas as abundant renewable energy resources. In addition, the test of raw biogas showed no deactivation of catalyst, justifying the implementation of the developed process for real biogas without purification.
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Dependence of MWCNT production via co-pyrolysis of industrial slop oil and ferrocene on growth temperature and heating rate
(2020-09-01)
Chaiwat, Weerawut
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Kaewtrakulchai, Napat
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Sangsiri, Pimpage
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Eiad-ua, Apiluck
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Wongwiriyapan, Winadda
Multi-walled carbon nanotubes (MWCNTs) could be produced from industrial slop oil via pyrolysis with the presence of ferrocene. Dependence of characteristics of the produced MWCNTs on their growth temperature and heating rate of mixtures of industrial slop oil and ferrocene was experimentally investigated. With low-molecular weighted hydrocarbon, the resultant MWCNTs with nominal diameters of 10–50 nm and yields of 45–65 wt% could be produced within a growth temperature range of 750–950 °C. Meanwhile, high-molecular weighted hydrocarbon could provide substantial yield of MWCNTs only within the growth temperature range of 850–950 °C. It was found that a higher heating rate of 9 °C/min could result in preferable production of MWCNTs with higher purity. Based on comprehensive analyses, a schematic pathway of MWCNT production via co-pyrolysis of mixtures of industrial slop oil and ferrocene was proposed.
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Synthesis of nanoporous material from lignin via carbonization assisted acid activation
(2020-01-01)
Ngamthanacom, Nutchaporn
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Kaewtrakulchai, Napat
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Chaiwat, Weerawut
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Chuenchom, Laemthong
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Fuji, Masayoshi
Waste lignin (WL) from the pulp mill and paper was studied for its potential application to prepare the nanoporous carbon with high porosity via carbonization assisted acid activation. The effect of acid activation such as HNO3, HCl, H2SO4, and H3PO4 on lignin transformation to nanoporous carbon investigated. The physicochemical properties of nanoporous carbon were comprehensively characterized through N2 sorption, Scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), respectively. N2 sorption revealed that the condition using 5% vol of phosphoric acid activation at carbonization temperature of 700°C for 2 h exhibited the highly porous structure of carbon nanoparticles with a total pore volume of 0.035 cm3 /g. With the properly selecting process variables of waste lignin development could be producing high porosity nanoporous carbon.
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Influence of acid-treatment on waste lignin for synthesis of carbon nanoparticles
(2019-01-01)
Ngamthanacom, Nutchaporn
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Kaewtrakulchai, Napat
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Chaiwat, Weerawut
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Chuenchom, Laemthong
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Fuji, Masayoshi
Waste lignin (WL) obtained from paper mills, was studied for its potential application in preparing carbon nanoparticles (CNPs) with high porosity. This was done by impregnation of 0, 5, 10 and 20% concentrations of phosphoric acid under various carbonization temperatures (600, 700, 800 and 900°C). The physicochemical properties of CNPs were characterized through nitrogen sorption, X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Fourier transforms infrared spectroscopy (FTIR). Nitrogen sorption revealed that the condition using 10% concentration of phosphoric acid treatment at a carbonization temperature of 700°C formed carbon nanoparticles with a highly porous structure (Surface area 27.65 m2 /g and pore volume 0.07 cm3 /g). Additionally, in order to high surface area, porosity and concentrated carbon nanoparticle.
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Sensitivity Enhancement of Benzene Sensor Using Ethyl Cellulose-Coated Surface-Functionalized Carbon Nanotubes
(2018-01-01)
Chobsilp, Thanattha
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Muangrat, Worawut
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Issro, Chaisak
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Chaiwat, Weerawut
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Eiad-Ua, Apiluck
A hybrid sensor based on the integration of functionalized multiwalled carbon nanotubes (MWCNTs) with ethyl cellulose (EC) was fabricated for sensitivity enhancement of benzene detection. To functionalize the surface of MWCNTs, MWCNTs were treated with hydrochloric acid for 60 min (A60-MWCNTs), while other MWCNTs were treated with oxygen plasma for 30, 60, 90, and 120 min (P30-MWCNTs, P60-MWCNTs, P90-MWCNTs, and P120-MWCNTs, resp.). Pristine MWCNTs, A-MWCNTs, and P-MWCNTs were dispersed in 1,2-dichloroethane, then dropped onto a printed circuit board consisting of Cu/Au electrodes used as the sensor platform. Next, EC was separately spin coated on the pristine MWCNTs, A-MWCNTs, and P-MWCNTs (EC/MWCNTs, EC/A-MWCNTs, and EC/P-MWCNTs, resp.). All sensors responded to benzene vapor at room temperature by increasing their electrical resistance which was sensitive to benzene vapor. The EC/P90-MWCNTs enabled an approximately 11-fold improvement in benzene detection compared to EC/MWCNTs. The sensitivity of all sensors would be attributed to the swelling of EC, resulting in the loosening of the MWCNT network after benzene vapor exposure. The differences of the sensing responses of the EC/MWCNTs, EC/A-MWCNTs, and EC/P-MWCNTs would be ascribed to the differences in crystallinity and functionalization of MWCNT sidewalls, suggesting that acid and oxygen plasma treatments of MWCNTs would be promising techniques for the improvement of benzene detection.
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Present advancement in production of carbon nanotubes and their derivatives from industrial waste with promising applications
(2017-01-01)
Kerdnawee, Konrat
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Termvidchakorn, Chompoopitch
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Yaisanga, Pacharaporn
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Pakchamsai, Jirapat
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Chookiat, Cheewapon
An increase in global consumption has led to an exponential increase in industrial production activities which inevitably results in overwhelming remain of industrial waste. Consequently it has driven increasing attentions of research and development teams in various countries to propose and investigate novel methodologies to utilize such industrial waste. Instead of using as alternative energy sources, usage of industrial waste for production of carbonaceous nanomaterials has been examined via various routes, such as catalytic pyrolysis, hydrothermal treatment and so on. Meanwhile, for sustainable and secure continuity of the carbonaceous nanomaterial production, broad spectra of promising applications have also been examined. Among those emerging applications, utilization of carbonaceous nanomaterials in pollution control and prevention has been focused worldwide. Therefore, in this review, relevant research works focusing on catalytic pyrolysis of carbonaceous industrial waste for carbonaceous nanomaterial production were comprehensively analyzed and summarized. In addition, promising applications involving with antibiotic removal, spilled oil handling and pollutant gas detection were also reviewed.

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