scholarly journals Application of Experimental Design to Hydrogen Storage: Optimisation of Lignin-Derived Carbons

2019 ◽  
Vol 5 (4) ◽  
pp. 82 ◽  
Author(s):  
Jemma Rowlandson ◽  
James Coombs OBrien ◽  
Karen Edler ◽  
Mi Tian ◽  
Valeska Ting
Keyword(s):  
Hydrogen Storage ◽  
Pore Size ◽  
Surface Area ◽  
Activated Carbons ◽  
Average Pore Size ◽  
High Surface ◽  
Hydrogen Uptake ◽  
Synthesis Process ◽  
Average Pore ◽  
Small Pore

Lignin is a significant by-product of the paper pulping and biofuel industries. Upgrading lignin to a high-value product is essential for the economic viability of biorefineries for bioethanol production and environmentally benign pulping processes. In this work, the feasibility of lignin-derived activated carbons for hydrogen storage was studied using a Design of Experiments methodology, for a time and cost-efficient exploration of the synthesis process. Four factors (carbonisation temperature, activation temperature, carbonisation time, and activation time) were investigated simultaneously. Development of a mathematical model allowed the factors with the greatest impact to be identified using regression analysis for three responses: surface area, average pore size, and hydrogen uptake at 77 K and 1 bar. Maximising the surface area required activation conditions using the highest settings, however, a low carbonisation temperature was also revealed to be integral to prevent detrimental and excessive pore widening. A small pore size, vital for efficient hydrogen uptake, could be achieved by using low carbonisation temperature but also low activation temperatures. An optimum was achieved using the lowest carbonisation conditions (350 °C for 30 min) to retain a smaller pore size, followed by activation under the severest conditions (1000 °C for 60 min) to maximise surface area and hydrogen uptake. These conditions yielded a material with a high surface area of 1400 m2 g−1 and hydrogen uptake of 1.9 wt.% at 77 K and 1 bar.

scholarly journals Low cost activated carbon prepared from Dipterocarpus alatus fruit

2020 ◽  
Vol 3 (SI3) ◽  
pp. first
Author(s):  
Yuvarat Ngernyen ◽  
Werawit Phiewruangnont ◽  
Narathorn Mahantadsanapong ◽  
Chantakorn Patawat ◽  
Ketsara Silakate ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Size ◽  
Surface Area ◽  
Activated Carbons ◽  
Low Cost ◽  
Average Pore Size ◽  
Carbon Adsorbents ◽  
Average Pore ◽  
Maximum Surface ◽  
Dipterocarpus Alatus

Dipterocarpus alatus tree grows prolifically throughout Thailand and can be tapped to yield significant quantities of oil to be used as natural diesel. However, such practices lead to waste dried fruit dropping from the tree. At present, there is no utilization of this dropped fruit, therefore costeffective processes need to be applied to obtain higher value products from this waste. A possible to utilization is the conversion to activated carbon for adsorption applications including the removal of heavy metals, dyes, and other contaminants in water purification and other decontamination process. A major challenge of current commercial activated carbon is the high production cost and recently it has been shown that chemical activators comprise a significant proportion of these costs. This feasibility study investigates the use of Dipterocarpus alatus fruit as raw material to produce low cost activated carbon adsorbents. Activated carbon was prepared from Dipterocarpus alatus fruit: endocarp, mesocarp, and wing by chemical activation with ZnCl2, FeCl3, and KOH. Each part of the fruit was impregnated with 30 wt% activating agent at a ratio of 1:2 for 1 h and then carbonized at 500 oC for a further 1 h. The surface area, pore volume, and average pore size of the resulting carbons were characterized by nitrogen gas adsorption. Activation of mesocarp with ZnCl2, KOH, and FeCl3 gave activated carbons with the surface area of 447, 256, and 199 m2/g, respectively. In the same way, ZnCl2 activation gave a maximum surface area of 312 and 278 m2/g for wing and endocarp, respectively. All of the aforementioned samples have an average pore size of around 2 nm. In contrast, KOH and FeCl3 activation of wing and endocarp produced activated carbon with very low surface area (below 25 m2/g), but with an average pore size of 5- 14 nm. The maximum surface area of activated carbon prepared from Dipterocarpus alatus fruit was higher than some literature examples for activated carbon from other biomass. Consequently, Dipterocarpus alatus fruit demonstrated significant potential as a feedstock for the preparation of low cost activated carbons.

Development and Characterization of Activated Carbons Derived from Lignocellulosic Material

2020 ◽  
Vol 988 ◽  
pp. 80-86
Author(s):  
Dewa Ngakan Ketut Putra Negara ◽  
Tjokorda Gde Tirta Nindhia ◽  
Lusiana ◽  
I. Made Astika ◽  
Cokorda Istri Putri Kusuma Kencanawati
Keyword(s):  
Activated Carbon ◽  
Pore Size ◽  
Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
High Surface ◽  
Carbonization Temperature ◽  
Lignocellulosic Material ◽  
Activation Time ◽  
Average Pore

Activated carbon is a multipurpose material due to its unique properties such as high surface area and pore volume. The reduced carbon source from coal has led to the development of activated carbon from lignocellulosic material. However, there is limited literature reported the use of swat bamboo (Gigantocholoa verticillata) as an activated carbon precursor. In this research, swat bamboo has been converted to activated carbons under different carbonization temperatures of 550, 650, and 750OC and activation durations of 1.5 and 2 h. The results show that at activation time of 1.5 h, increasing carbonization temperature affecting the higher pore volume and surface area gained. The optimal characteristics of activated carbon were obtained at a carbonization temperature of 750OC and activation time of 1.5 h. This due to the activated carbon produced in this condition has the highest pore volume, surface area, and adsorption capacity of 0.138 cm3/g, 135.30 m2/g, and 95.776 cm3/g, respectively. Its average pore diameter was 2.053 nm with fix carbon of 75.26% and C of 76.79%. It has a monomodal pore size distribution with the highest adsorption of 0.056 cm3/g/nm occurred at a pore size of 1.516 nm.

scholarly journals Colour reduction of biodiesel from crude palm oil by using activated carbon prepared from chilli stem

10.29007/ps3m ◽  
2020 ◽  
Author(s):  
Yuvarat Ngernyen ◽  
Werawit Phiewruangnont ◽  
Ratchapon Anachai ◽  
Andrew Hunt
Keyword(s):  
Activated Carbon ◽  
Pore Size ◽  
Surface Area ◽  
Palm Oil ◽  
Average Pore Size ◽  
Raw Material ◽  
Batch Adsorption ◽  
Crude Palm Oil ◽  
Average Pore ◽  
Small Pore

This present work aims to reduce the color of biodiesel from crude palm oil through the application of activated carbon prepared from chili stem waste. Chilli stem was converted into activated carbon using 30 wt% KOH at a ratio of 1:2 for 1 h, followed by carbonization at 500 oC under an N2 atmosphere for a further hour. Physico-chemical characteristics of the raw material and activated carbon were analyzed including thermogravimetric analysis, proximate analysis, and porosities. The results demonstrated that the activated carbon was a porous material with a highly mesoporous structure (84.5%). The surface area of activated carbon was 10.6 m2/g and it exhibited an average pore diameter of 27.25 nm which was suitable for the removal of large highly colored molecules. Batch adsorption experiments were performed to investigate the reduction in color of the biodiesel. Ratios of activated carbon to biodiesel of 0.002 and 0.1 w/v were used in the study. For comparison, the adsorption was also tested against a commercial activated carbon with a surface area of 1,130 m2/g, but lower average pore size of 3.72 nm. The chili stem activated carbon can reduce color by approximately 15% within 24 h and the maximum color reduction was 95% after 96 h for both activated carbon to biodiesel ratios. The color of biodiesel changes from dark red to yellow and eventually resulted in a pale yellow color with longer adsorption times and was deemed more attractive for use. Moreover, commercial activated carbon with its small pore size could not reduce the color, with a maximum reduction of only 3%.

scholarly journals Hydrogen uptake of high surface area-activated carbons doped with nitrogen

2013 ◽  
Vol 38 (25) ◽  
pp. 10453-10460 ◽  
Author(s):  
W. Zhao ◽  
V. Fierro ◽  
N. Fernández-Huerta ◽  
M.T. Izquierdo ◽  
A. Celzard
Keyword(s):  
Surface Area ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
Hydrogen Uptake

Properties of Hydrophilic Chitosan/Polysulfone Nanofibrous Filtration Membrane

2014 ◽  
Vol 9 (1) ◽  
pp. 155892501400900 ◽  
Author(s):  
Leigen Liu ◽  
Zhijuan Pan
Keyword(s):  
Mechanical Properties ◽  
Pore Size ◽  
Average Pore Size ◽  
High Surface ◽  
Chitosan Solution ◽  
Water Filtration ◽  
Average Pore ◽  
Filtration Membrane ◽  
Crosslinked Chitosan ◽  
Nanofibrous Membranes

Electrospun nanofibrous membranes are useful water filtration materials due to their high interconnected porosity and tunable pore sizes, which cause very high permeability and selectivity. However, poor mechanical properties and easy fouling due to their extremely high surface area limit their applications. Therefore, it is desirable to enhance the mechanical properties and the hydrophilicity of such electrospun nanofibrous membranes. In this paper, electrospun polysulfone (PSF) nanofibrous membranes were treated with plasma. Crosslinked chitosan solution was then employed to pad the membranes. We studied the influence of the chitosan concentration and the volume of glutaraldehyde on the morphology, porosity structure, mechanical properties and hydrophilicity of electrospun polysulfone nanofibrous membranes. The results showed that the average pore size decreased from 4.5 μm to 2.68 μm, the breaking stress increased from 6.01±0.44 MPa to 9.25±0.45 MPa, and the water contact angle decreased from 130.8° to 0° in 30 s when chitosan was applied to the membranes. These changes occurred by padding due to the crosslinked chitosan solution. The results indicate that a significant improvement occurred in the mechanical properties; the highly hydrophobic PSF membrane was changed to a superhydrophilic one and the pore size was reduced. These results encouraged us to propose this material as a water filtration membrane with longer life span, lower fouling and higher rejection efficiency.

Synergy of Pore Size and Specific Surface Area on the CO2 Sorption Performance of Nano CaO-Based Sorbents

2019 ◽  
Vol 19 (6) ◽  
pp. 3205-3209 ◽  
Author(s):  
Shangqing Lu ◽  
Qirui Lin ◽  
Sufang Wu
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Sorption Capacity ◽  
Specific Surface Area ◽  
Partial Correlation ◽  
Average Pore Size ◽  
Partial Correlation Analysis ◽  
Average Pore ◽  
Carbon Dioxide Sorption

This study focuses on the synergy effect of pore size and specific surface area (SSA) on the carbon dioxide sorption performance. Nano CaO-based CO2 sorbents with various pore size (15–55 nm) under similar SSA, and different SSA (14.50–48.90 m2/g) under similar pore size are prepared using selected organic templates. Results indicate that increasing the proportion of macropore in 47–96 nm could significantly improve sorbent’s sorption rate and corresponding sorption capacity. Besides, sorption capacity could be also by SSA. Moreover, partial correlation analysis reveals that sorption capacity is slightly more dependent on average pore size than SSA.

Determination of the Permeability of Carbon Aerogels by Gas Flow Measurements

1992 ◽  
Vol 270 ◽  
Author(s):  
F-M. Kong ◽  
S.S. Hulsey ◽  
C.T. Alviso ◽  
R.W. Pekala
Keyword(s):  
Pore Size ◽  
Gas Flow ◽  
Cell Structure ◽  
Average Pore Size ◽  
High Surface ◽  
High Surface Area ◽  
Carbon Aerogels ◽  
Average Pore ◽  
Thin Specimen ◽  
Flow Measurements

ABSTRACTCarbon aerogels are synthesized via the polycondensation of resorcinol and formaldehyde, followed by supercritical drying and pyrolysis at 1050 °C in nitrogen. Because of their interconnected porosity, ultrafine cell structure and high surface area, carbon aerogels have many potential applications, such as in supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, we calculated the permeability of carbon aerogels from equations based upon Darcy's law. Our measurements show that carbon aerogels have apparent permeabilities on the order of 10−12 to 10−10 cm2 for densities ranging from 0.44 to 0.05 g/cm3. Like their mechanical properties, the permeability of carbon aerogels follows a power law relationship with density and average pore size. Such findings help us to estimate the average pore sizes of carbon aerogels once their densities are known. This paper reveals the relationships among permeability, pore size and density in carbon aerogels.

Catalytic Oxidation of Toluene with Ozone Over the Ru-Mn/Desilicated Nanoporous H-Zeolite Socony Mobil-5 at Room Temperature

2021 ◽  
Vol 21 (7) ◽  
pp. 3868-3871
Author(s):  
Jihee Kim ◽  
Jung Eun Lee ◽  
Abid Farooq ◽  
Sang Chai Kim ◽  
Sang-Chul Jung ◽  
...  
Keyword(s):  
Pore Size ◽  
Catalytic Oxidation ◽  
Surface Area ◽  
Removal Efficiency ◽  
Pore Volume ◽  
Bimetallic Catalysts ◽  
Room Temperature ◽  
Average Pore Size ◽  
Average Pore ◽  
Zeolite Support

In this study, the effect of Ru-Mn bimetallic catalysts in combination with a zeolite support on the removal of toluene in the presence of ozone at room temperature was investigated. Desili-cated HZSM-5 (DZSM) was fabricated and applied as a Ru-Mn support for the removal of toluene (100 ppm) in the presence of ozone (1000 ppm) at room temperature. The surface area, pore volume, and average pore size of Ru-Mn with a DZSM support (RuMn/DZSM) were measured and compared with those of Ru-Mn/HZSM-5 (RuMn/HZSM). The pore size of RuMn/DZSM (69 Å) was much larger than that of RuMn/HZSM-5 (5.5 Å). In addition, the pore volumes of RuMn/DZSM and RuMn/HZSM were 0.64 and 0.25 cm3/g, respectively. Furthermore, the ratios of Mn3+/Mn4+ and Ovacancy/Olattice of RuMn/DZSM were larger than those of RuMn/HZSM-5. The removal efficiency of toluene of RuMn/DZSM was higher than that of RuMn/HZSM due to its larger pore volume, pore size, and the increased ratios of Mn3+/Mn4+ and Ovacancy/Olattice.

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