scholarly journals Characteristics of Smoldering on Moist Rice Husk for Silica Production

2021 ◽  
Vol 14 (1) ◽  
pp. 317
Author(s):  
Shengtai Yan ◽  
Dezheng Yin ◽  
Fang He ◽  
Junmeng Cai ◽  
Thomas Schliermann ◽  
...  
Keyword(s):  
Moisture Content ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Silica Content ◽  
Muffle Furnace ◽  
High Quality

In order to assess the possibility of silica production via smoldering of moist rice husk, experiments of washed (moist) rice husk (7 kg with moisture content of 51%) in a newly designed smoldering apparatus was performed. The temperature inside the fuel bed during smoldering was recorded, and characteristics of ash were analyzed. Results showed that the highest temperature in the middle of the naturally piled fuel bed was about 560.0 °C, lower than those in most of combustors. Some volatiles from the lower part of the fuel bed adhere to its upper ash during piled smoldering. Silica content and specific surface area of ash from smoldering of washed (moist) rice husk were 86.4% and 84.9 m2/g, respectively. Compared to our experiments, they are close to smoldering of unwashed rice husk (89.0%, 67.7 m2/g); different from muffle furnace burning (600 °C, 2 h) of washed (93.4%, 164.9 m2/g) and un-washed (90.2%, 45.7 m2/g) rice husk. The specific surface area is higher than those from most industrial methods (from 11.4 to 39.3 m2/g). After some improvements, the smoldering process has great potential in mass product of high quality silica directly from moist rice husk.

Synthesis of High Quality Porous Carbon from Water Hyacinth

2020 ◽  
Vol 860 ◽  
pp. 173-177
Author(s):  
Otong Nurhilal ◽  
Renaldy Sharin Lesmana ◽  
Karina Ramadayanti ◽  
Sholihatul Habibah ◽  
Sahrul Hidayat ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Water Hyacinth ◽  
Invasive Plant ◽  
Proximate Analysis ◽  
High Quality ◽  
Porous Volume ◽  
Adsorption Desorption

Water Hyacinth (WH) is a plant that can absorb various pollutants in water. However, this plant is categorized as an invasive plant that can become a weed in the waters. To improve the functionality of WH, processing of WH is needed to be used for various applications. One of modifications of WH is as porous carbon for battery cathode composite. In this paper, we reported a synthesis of a porous carbon from WH. WH is processed into carbon by carbonization at various temperatures of 400, 500 and 600 °C with various activators of KOH, H3PO4 and ZnCl2 to obtain high quality porous carbon which has high electrical conductivity, large specific surface area and large porous volume. All synthesized carbons were characterized by proximate analysis measurements, scanning electron microscopy (SEM), and N2 adsorption-desorption measurements. The highest carbon fixed content of 37.79% is obtained from charcoal with a carbonization temperature of 400 °C. The largest specific surface area of 264.77 m2/g was obtained from activated carbon with H3PO4 as activator. The values of pore volume and pore radius were 0.186 cm3/g and 1.56 nm, respectively.

scholarly journals PHYSICOCHEMICAL PROPERTIES AND POZZOLANIC PERFORMANCE OF ULTRAFINE TREATED RICE HUSK ASH (UFTRHA) AS ADDITIVE IN CONCRETE

2018 ◽  
Vol 16 ◽  
Author(s):  
Siti Asmahani Saad ◽  
Nasir Shafiq ◽  
Maisarah Ali
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Rice Husk Ash ◽  
High Energy ◽  
Size Analysis ◽  
Pre Treatment

Rice husk ash (RHA) contains high amount of amorphous silica that is ubiquitous in the pozzolanic reaction of SCM in concrete. However, usage of conventional RHA is currently unfavourable in concrete industry due to its properties inconsistency. In this regard, improvement on the RHA properties by introduction of thermochemical pre-treatment prior to burning procedure is seen as an excellent way to reach the goal. In this paper, raw rice husk was pre-treated using 0.1N hydrochloric acid (HCl) and heated at 80oC. It was then mechanically activated by high energy planetary ball mill for 15 minutes at speed of 300rpmand ball-to-powder ratio (BPR) of 15:1. The chemical composition, mineralogical properties, particle size analysis, specific surface area as well as microstructure properties of ultrafine treated rice husk ash (UFTRHA) were determined accordingly. As for amorphous silica content of the optimum sample was recorded as 98.60% incinerated at 600oC with four hours of pre-treatment soaking duration. In terms of particle size and specific surface, it was also observed that, burning temperature of 600oC, pre-treated at four hours were recorded to produce finest size of UFTRHA where d(0.1), d(0.5) and d(0.9) were obtained as 1.416?m, 4.364 ?m and 14.043 ?m respectively. Largest specific surface area value was obtained at 219.58 m2/g with the similar pre-treatment conditions. Meanwhile, the strength activity of UFTRHA from the optimum pre-treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.17MPa with 3% UFTRHA replacement at 28 days.

Co-Producing Active Carbons and Sodium Silicate from Pyrolyzed Rice Husk by CO2 Activation Coupled with NaOH Solution Boiling

2014 ◽  
Vol 595 ◽  
pp. 30-35
Author(s):  
Da Wei Li ◽  
Xi Feng Zhu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Sodium Silicate ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Active Carbon ◽  
Desirability Function ◽  
Active Carbons ◽  
Solid Ratio ◽  
Naoh Solution

Active carbon and sodium silicate were produced simultaneously from pyrolyzed rice husk (PRH) by CO2 activation coupled with NaOH solution boiling. Doehlert matrix and Derringer's desirability function were applied to optimizing the boiling conditions to achieve a large specific surface area, a high silica extraction and low alkali consumption. In terms of this purpose, the optimum condition was determined as boiling CO2-activated char with 1mol/L NaOH solution at a liquid/solid ratio of 9.7 mL/g. Under this condition, the modulus of the sodium silicate and the specific surface area (SSA) of the active carbon were 2.62 and 897 m2/g, respectively. The values both reached their respective commercial levels. The pretreatment of the PRH with CO2 activation can markedly increase the SSA of active carbons.

scholarly journals The influence factors for gas adsorption with different ranks of coals

2017 ◽  
Vol 36 (3-4) ◽  
pp. 904-918 ◽  
Author(s):  
Deyong Guo ◽  
Xiaojie Guo
Keyword(s):  
Moisture Content ◽  
Specific Surface ◽  
Pore Structure ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Total Pore Volume ◽  
Factors Influencing

In this paper, scanning electron microscopy, low-temperature N2 adsorption and CH4 isothermal adsorption experiments were performed on 11 coal samples with Ro,max between 0.98 and 3.07%. The pore structure characteristics of coals (specific surface area, total volume distribution) were studied to assess the gas adsorption capacity. The results indicate that there is significant heterogeneity on coal surface, containing numerous channel-like pores, bottle-shaped pores and wedge-shaped pores. Both Langmuir volume (VL) and Langmuir pressure (PL) show a stage change trend with the increase of coalification degree. For different coalification stages, there exist different factors influencing the VL and PL values. For low-rank coals (Ro,max < 1.1%), the increase of VL values and decrease of PL values are mainly due to the abundant primary pore and fracture within coal. For middle-rank coals (1.1% < Ro,max < 2.1%), the moisture content, vitrinite content and total pore volume are all the factors influencing VL, and the reduction of PL is mainly attributed to the decrease of moisture content and inertinite content. Meanwhile, this result is also closely related to the pore shape. For high-rank coals (Ro,max > 2.1%), VL values gradually increase and reach the maximum. When the coal has evolved into anthracite, liquid hydrocarbon within pore begins pyrolysis and gradually disappears, and a large number of macropores are converted into micropores, leading to the increase of specific surface area and total pore volume, corresponding to the increase of VL. In addition, the increase of vitrinite content within coal also contributes to the increase of VL. PL, reaches the minimum, indicating that the adsorption rate reaches the largest at the low pressure stage. The result is mainly controlled by the specific surface area and total pore volume of coal samples. This research results will provide a clearer insight into the relationship between adsorption parameters and coal rank, moisture content, maceral composition and pore structure, and it is of great significance for better assessing the gas adsorption capacity.

New Insight Technique for Synthesis of Silica Gel from Rice Husk Ash by Using Microwave Radiation

2014 ◽  
Vol 1025-1026 ◽  
pp. 574-579 ◽  
Author(s):  
Nuchanaporn Pijarn ◽  
Pichit Galajak
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Silica Gel ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Pore Volume ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Microwave Technique

Silica gel is the chemical substance that has many good advantages such as absorbed moisture, porosity, small diameter, high surface area, and lightweight. It was synthesized by using rice husk ash via sol – gel heating in the microwave technique. The objectives in this work compose of synthesis silica gel by using the microwave technique before characterizatization. This raw material was archived from rice husk ash, obtained from agricultural waste. The silica gel, synthesized by conventional method (CVM) and commercial silica gel (COM), was also studied for comparison purposes. The results showed that successfully synthesized the silica gel by sol - gel technique using microwave. The XRD pattern of silica gel enhanced from this method was not sinificantly different as compared with CVM and COM methods. And the physical properties of this technique could be debated. The particle size of silca gel was determined by zetasizer and it was approxmately 50-70 nm. The pore size diameter, pore volume, and specific surface area of silica gel were calculated by Flowsorb II and a Quantachrome Autosorp-1. The pore size diameter, pore volume, and specific surface area of silica gel are 10-30 nm, 0.7-1.0 cm3/g, and 400-700 m2/g, respectively. Consequently, this work is considered to be the waste to make useful, and a great way to save energy and time in the silica gel synthesis.

scholarly journals SYNTHESIS OF PURE SILICA FROM RICE HUSK ASH AS AN ANTI–CAKING AGENT FOR FERTILIZER INDUSTRY IN VIETNAM

2018 ◽  
Vol 55 (1B) ◽  
pp. 193
Author(s):  
Nguyen Huu Hieu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Silica Particles ◽  
Average Particle ◽  
X Ray ◽  
Pure Silica ◽  
Npk Fertilizer

Pure silica particles have been successfully synthesized from rice husk ash (RHA) by precipitation method. The characterization of silica was performed by X–ray diffraction, X–ray fluorescence, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller specific surface area, and transmission electron microscopy. The characterization results show that the obtained amorphous silica was 99.8 % purity with average particle size of 5–10 nm, and high specific surface area of 224 m2/g. Additionally, for the first time that RHA–silica was successfully applied as an anti–caking agent for a NPK–fertilizer. A suitable content of silica was evaluated through the level of anti–caking. The testing results show that with only 1.5 wt% of RHA–silica particles could replace kaolin as an anti–caking agent for the NPK–fertilizer. 

scholarly journals PHYSICOCHEMICAL PROPERTIES AND POZZOLANIC PERFORMANCE OF ULTRAFINE TREATED RICE HUSK ASH (UFTRHA) AS ADDITIVE IN CONCRETE

2018 ◽  
Vol 16 (6) ◽  
Author(s):  
Siti Asmahani Saad ◽  
Nasir Shafiq ◽  
Maisarah Ali
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Rice Husk Ash ◽  
High Energy ◽  
Size Analysis ◽  
Pre Treatment

Rice husk ash (RHA) contains high amount of amorphous silica that is ubiquitous in the pozzolanic reaction of SCM in concrete. However, usage of conventional RHA is currently unfavourable in concrete industry due to its properties inconsistency. In this regard, improvement on the RHA properties by introduction of thermochemical pre-treatment prior to burning procedure is seen as an excellent way to reach the goal. In this paper, raw rice husk was pre-treated using 0.1N hydrochloric acid (HCl) and heated at 80oC. It was then mechanically activated by high energy planetary ball mill for 15 minutes at speed of 300rpmand ball-to-powder ratio (BPR) of 15:1. The chemical composition, mineralogical properties, particle size analysis, specific surface area as well as microstructure properties of ultrafine treated rice husk ash (UFTRHA) were determined accordingly. As for amorphous silica content of the optimum sample was recorded as 98.60% incinerated at 600oC with four hours of pre-treatment soaking duration. In terms of particle size and specific surface, it was also observed that, burning temperature of 600oC, pre-treated at four hours were recorded to produce finest size of UFTRHA where d(0.1), d(0.5) and d(0.9) were obtained as 1.416?m, 4.364 ?m and 14.043 ?m respectively. Largest specific surface area value was obtained at 219.58 m2/g with the similar pre-treatment conditions. Meanwhile, the strength activity of UFTRHA from the optimum pre-treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.17MPa with 3% UFTRHA replacement at 28 days.

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