scholarly journals Assessment on the Effect of Sulfuric Acid Concentration on Physicochemical Properties of Sulfated-Titania Catalyst and Glycerol Acetylation Performance

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1542
Author(s):  
Mohamad Rasid Shera Farisya ◽  
Ramli Irmawati ◽  
Ishak Nor Shafizah ◽  
Yun Hin Taufiq-Yap ◽  
Ernee Noryana Muhamad ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Surface Area ◽  
Acid Concentration ◽  
Active Sites ◽  
Solid Acid Catalyst ◽  
Sulfuric Acid Concentration ◽  
Catalyst Loading ◽  
Impregnation Method ◽  
Sulfated Titania ◽  
Glycerol Conversion

In this research, a solid acid catalyst was synthesized to catalyse glycerol acetylation into acetins. The sulphated-titania catalysts were prepared via the wet impregnation method at different sulfuric acid concentrations (5%, 10%, 15%, and 20%) and denoted as 5SA, 10SA, 15SA, and 20SA, respectively. The synthesized catalysts were characterized using FTIR, XRD, TGA, BET, NH3-TPD, XRF, and SEM-EDX. The synthesized catalysts were tested on glycerol acetylation reaction at conditions: 0.5 g catalyst loading, 100–120 °C temperature, 1:6 glycerol/acetic acid molar ratios, and 2–4 h reaction time. The final product obtained was analysed using GC-FID. An increment in sulfuric acid concentration reduces the surface area, pore volume, and particles size. However, the increment has increased the number of active sites (Lewis acid) and strong acid strength. 15SA catalyst exhibited excellent glycerol conversion (>90%) and the highest selectivity of triacetin (42%). Besides sufficient surface area (1.9 m2 g−1) and good porosity structure, the great performance of the 15SA catalyst was attributed to its high acid site density (342.6 µmol g−1) and the high active site of metal oxide (95%).

scholarly journals MODIFIKASIZEOLIT ALAM MORDENIT SEBAGAI KATALISATOR KETALISASI DAN ESTERIFIKASI

REAKTOR ◽  
2016 ◽  
Vol 16 (2) ◽  
pp. 72
Author(s):  
Nuryoto - Nuryoto ◽  
Hary Sulistyo ◽  
Wahyudi Budi Sediawan ◽  
Indra Perdana
Keyword(s):  
Sulfuric Acid ◽  
Temperature Variation ◽  
Surface Area ◽  
Acid Concentration ◽  
Natural Zeolite ◽  
Heating Temperature ◽  
Sulfuric Acid Concentration ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Acid Esterification

Abstract MODIFIED  MORDENITE NATURAL ZEOLITE AS CATALYST FOR KETALIZATION AND ESTERIFICATION. The aims of this research was studied of  modified mordenite natural zeolite from Bayah effect by acidity and heating to change zeolite characteristics in orde to prepare as catalyst for glycerol ketalization and  acetit acid esterification by some reaction temperature variation. Natural zeolite which modified by precise treatment will be  produced of natural zeolite that ready for use as catalyst and has good perfomance. The characterization results showed that the best condition for modified mordenite natural zeolite of  Bayah achieved at sulfuric acid concentration of 6 N and heating temperature of 200oC, by surface area reached of 157.110 m2/g and cation exchanged capacity of 2.11 meq/ml. Modernite natural zeolite of Bayah has good performance indication as a catalyst, by the highest glycerol conversion of  70.10% at 60°C for the ketalization reaction, and for the esterification reaction, mordenit natural zeolit of Bayah able to acetit acid conversion of 11.72% at 70°C.   Keywords: characterization; esterification; glycerol; modified; ketalization Abstrak Penelitian ini bertujuan untuk untuk mempelajari pengaruh modifikasi dengan pengasaman dan pemanasan terhadap perubahan karakteristik zeolit alam mordenit dari Bayah guna persiapan sebagai katalisator pada reaksi ketalisasi gliserol dan esterifikasi asam asetat dengan beberapa variasi suhu reaksi. Zeolit alam yang termodifikasi dengan perlakuan yang tepat akan menghasilkan zeolit alam yang siap pakai, dan akan mampu menghasilkan performa yang baik. Hasil pengujian karakterisasi menunjukkan bahwa kondisi terbaik pada modifikasi zeolit alam mordenit Bayah dihasilkan pada konsentrasi pengasaman 6N H2SO4 dan suhu pengeringan 200oC dengan luas permukaan 157,110 m2/g dan kemampuan tukar kation sebesar 2,11 meq/ml. Zeolit alam mordenit Bayah menunjukkan performa yang baik sebagai katalisator dengan konversi gliserol tertinggi sebesar 70,10%  yang dicapai pada suhu 60oC pada reaksi ketalisasi, dan untuk reaksi esterifikasi,  zeolit alam mordenit Bayah mampu mengkonversi asam setat sebesar 11,72% pada suhu 70oC. Kata kunci: karakterisasi; esterifikasi; gliserol; modifikasi; ketalisasi

scholarly journals Aerosol Surface Area Concentration: a Governing Factor for New Particle Formation in Beijing

2017 ◽  
Author(s):  
Runlong Cai ◽  
Dongsen Yang ◽  
Yueyun Fu ◽  
Xing Wang ◽  
Xiaoxiao Li ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Surface Area ◽  
Acid Concentration ◽  
Mass Concentration ◽  
Sulfuric Acid Concentration ◽  
Particle Formation ◽  
Atmospheric Environment ◽  
Geometric Standard Deviation ◽  
Growth Enhancement ◽  
New Particle Formation

Abstract. The predominating role of aerosol Fuchs surface area, AFuchs, in determining the occurrence of new particle formation (NPF) events in Beijing was elucidated in this study. Analysis was based on a field campaign from March 12th to April 6th, 2016, in Beijing, during which aerosol size distributions down to ~ 1 nm and sulfuric acid concentration were simultaneously monitored. The 26 days were classified into 11 typical NPF days, 2 undefined days, and 13 non-event days. A dimensionless factor, LΓ, characterizing the relative ratio of the coagulation scavenging rate over the condensational growth rate and predicting whether or not a NPF event would occur (Kuang et al., 2010), was applied. The three parameters determining LΓ are sulfuric acid concentration, the growth enhancement factor characterizing contribution of other gaseous precursors to particle growth, Γ, and AFuchs. Different from other atmospheric environment such as in Boulder and Hyytiälä, the variations of daily maximum sulfuric acid concentration and Γ in Beijing are in a narrow range with geometric standard deviations of 1.40 and 1.31, respectively. Positive correlation was found between estimated new particle formation rate, J1.5, and sulfuric acid concentration with a mean fitted exponent of 2.4. However, sulfuric acid concentration on NPF days is not significantly higher than that on non-event days. Instead, AFuchs varies greatly among days in Beijing with a geometric standard deviation of 2.56, while it is relatively stable at other locations such as Tecamac, Atlanta, and Boulder. Good correlation was found between AFuchs and LΓ in Beijing (R2 = 0.88). It appears that the abundance of gaseous precursors such as sulfuric acid in Beijing is high enough to have nucleation, however, it is AFuchs that determines the occurrence of NPF event in Beijing. 10 in 11 NPF events occurred when AFuchs is smaller than 200 μm2/cm3, and the NPF event was suppressed due to coagulation scavenging when AFuchs is larger than 200 μm2/cm3. Measured AFuchs is in good correlation with PM2.5 mass concentration (R2 = 0.85) since AFuchs in Beijing is mainly determined by particles in the size range of 50–500 nm that also contribute to PM2.5 mass concentration.

scholarly journals PEMBUATAN BIOSORBEN DARI BIJI PEPAYA (Carica papaya L) UNTUK PENYERAPAN ZAT WARNA

2017 ◽  
Vol 6 (2) ◽  
pp. 7-13
Author(s):  
Siswarni MZ ◽  
Lara Indra Ranita ◽  
Dandri Safitri
Keyword(s):  
Sulfuric Acid ◽  
Methyl Orange ◽  
Surface Area ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Methyl Violet ◽  
Methyl Red ◽  
Drying Time ◽  
Adsorption Time ◽  
Papaya Seeds

Biosorbent is a material that has a pore - pore lot, where the adsorption process can take place on the pore walls or occur in certain regions of the particles. Preparation from papaya seeds biosorbent using H2SO4 as an activator, and then used as a textile dye absorption, namely methyl orange, methyl violet and methyl red. This study aims to determine the optimum conditions in the manufacturing biosorbent from papaya seeds. Analysis is iodine number, surface area, and test the ability of sarap to dyes (methyl orange, methyl violet and methyl red). In the manufacture biosorbent of this papaya seeds, the method used is chemical activation process. This study uses papaya seeds as raw material and sulfuric acid as an activator. The concentration of sulfuric acid used 5%, 7%, 10% and the drying time of 30 minutes, 60 minutes, 90 minutes, and 120 minutes. Biosorbent mass of 0.5 g (2.5% of 20 ml), 1.0 g (5% of 20 ml) and 1.5 g (7.5% of 20 ml) with adsorption time of 20 minutes, 30 minutes, and 40 minutes for the absorption of the dye. The results showed the highest iodine gained 482.22 mg / g on the drying time of 120 minutes and a sulfuric acid concentration of 10% and the highest surface area was obtained 33.43556 m2 / g on the drying time of 120 minutes and a sulfuric acid concentration of 10%. The analysis results of the adsorption capacity for methyl violet dye that is 9.547 mg / g on biosorbent mass of 1.0 g and the adsorption time of 40 minutes..

scholarly journals Aerosol surface area concentration: a governing factor in new particle formation in Beijing

2017 ◽  
Vol 17 (20) ◽  
pp. 12327-12340 ◽  
Author(s):  
Runlong Cai ◽  
Dongsen Yang ◽  
Yueyun Fu ◽  
Xing Wang ◽  
Xiaoxiao Li ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Surface Area ◽  
Acid Concentration ◽  
Mass Concentration ◽  
Sulfuric Acid Concentration ◽  
Particle Formation ◽  
Geometric Standard Deviation ◽  
Daily Maximum ◽  
Growth Enhancement ◽  
New Particle Formation

Abstract. The predominating role of aerosol Fuchs surface area, AFuchs, in determining the occurrence of new particle formation (NPF) events in Beijing was elucidated in this study. The analysis was based on a field campaign from 12 March to 6 April 2016 in Beijing, during which aerosol size distributions down to  ∼  1 nm and sulfuric acid concentrations were simultaneously monitored. The 26 days were classified into 11 typical NPF days, 2 undefined days, and 13 non-event days. A dimensionless factor, LΓ, characterized by the relative ratio of the coagulation scavenging rate over the condensational growth rate (Kuang et al., 2010), was applied in this work to reveal the governing factors for NPF events in Beijing. The three parameters determining LΓ are sulfuric acid concentration, the growth enhancement factor characterized by contribution of other gaseous precursors to particle growth, Γ, and AFuchs. Different from other atmospheric environments, such as in Boulder and Hyytiälä, the daily-maximum sulfuric acid concentration and Γ in Beijing varied in a narrow range with geometric standard deviations of 1.40 and 1.31, respectively. A positive correlation between the estimated new particle formation rate, J1.5, and sulfuric acid concentration was found with a mean fitted exponent of 2.4. However, the maximum sulfuric acid concentrations on NPF days were not significantly higher (even lower, sometimes) than those on non-event days, indicating that the abundance of sulfuric acid in Beijing was high enough to initiate nucleation, but may not necessarily lead to NPF events. Instead, AFuchs in Beijing varied greatly among days with a geometric standard deviation of 2.56, whereas the variabilities of AFuchs in Tecamac, Atlanta, and Boulder were reported to be much smaller. In addition, there was a good correlation between AFuchs and LΓ in Beijing (R2 = 0.88). Therefore, it was AFuchs that fundamentally determined the occurrence of NPF events. Among 11 observed NPF events, 10 events occurred when AFuchs was smaller than 200 µm2 cm−3. NPF events were suppressed due to the coagulation scavenging when AFuchs was greater than 200 µm2 cm−3. Measured AFuchs in Beijing had a good correlation with its PM2.5 mass concentration (R2 = 0.85) since AFuchs in Beijing was mainly determined by particles in the size range of 50–500 nm that also contribute to the PM2.5 mass concentration.

Behaviors of Carbon in Different Concentration of Sulfuric Acid

2010 ◽  
Vol 146-147 ◽  
pp. 18-21 ◽  
Author(s):  
Rui Rui Zhao ◽  
Dong Shu ◽  
Hong Yu Chen
Keyword(s):  
Sulfuric Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Acid Concentration ◽  
Activated Carbons ◽  
Sulfuric Acid Concentration ◽  
Average Pore ◽  
Transmission Electron ◽  
Adsorption Desorption

N2 adsorption-desorption method, scanning electron microscope and transmission electron microscopy were employed to test changes of the specific surface area, average pore diameter and appearances of activated carbons treated with different concentration of sulfuric acid. It can be concluded that these performances altered with sulfuric acid concentration. Activated carbon can be oxidized when the acid concentration increase to a certain value and this process takes time that sulfuric acid molecules first insert in the pore of the carbon which represented by reduction of the specific surface area of carbon and then oxidization occurred. This study is very significant in the development of carbon which is suitable for lead acid battery.

scholarly journals Release of reducing sugars from water hyacinth by thermochemical and enzymatic hydrolysis

2021 ◽  
Vol 6 (1) ◽  
pp. 156-164
Author(s):  
Jessica E. Guzmán-Pérez ◽  
◽  
Oscar J. Salinas-Luna ◽  
Ernesto Favela-Torres ◽  
Nohemi López-Ramírez ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Acid Concentration ◽  
Water Hyacinth ◽  
Dry Matter ◽  
Eichhornia Crassipes ◽  
Reducing Sugars ◽  
Sulfuric Acid Concentration ◽  
Raw Material ◽  
Thermochemical Pretreatment

Water hyacinth (Eichhornia crassipes) is considered a pernicious herb in many parts of the world due to its rapid growth. However, for its high content of cellulose and hemicellulose, it could be considered as raw material to produce fermentable sugars. In this work, the effect of sulfuric acid concentration by thermochemical pretreatment and enzymatic hydrolysis on the release of sugars from water hyacinth was evaluated. Initially, the effect of the sulfuric acid concentration from 1.5 to 9% at 120 ºC was evaluated. With 1.5%, the release of reducing sugars was 160 milligrams of reducing sugars per gram of dry matter (mg red-sug/g dm). After the thermochemical pretreatment, the enzymatic hydrolysis with the cellulase complex (NS22086) allowed obtaining a reducing sugars concentration up to 317 mg red-sug/g dm. These thermochemical and enzymatic approaches to recover reducing sugars from water hyacinth is promising and should be evaluated for bioprocess using reducing sugars as the main source of carbon, such as bioethanol production.

scholarly journals Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 565 ◽  
Author(s):  
Norman Toro ◽  
Nelson Herrera ◽  
Jonathan Castillo ◽  
Cynthia Torres ◽  
Rossana Sepúlveda
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Room Temperature ◽  
Sulfuric Acid Concentration ◽  
Extraction Rate ◽  
Molar Ratio ◽  
Independent Variables ◽  
Initial Investigation ◽  
Optimization Methodology

In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maximum Mn extraction rate was obtained when a MnO2 to Fe molar ratio of 0.5, 1 M of H2SO4, −320 + 400 Tyler mesh (−47 + 38 μm) nodule particle size and a leaching time of 30 min were used.

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