Activated Rice Husk Research Articles

Transesterification of biodiesel from kapok seed oil (ceiba pentandra) using a natural heterogeneous katalyst (rice husk activation)

Biodiesel as a renewable energy source can be produced by a chemical reaction between vegetable oil or animal fat and short-chain alcohol such as methanol, ethanol or buthanol and is supported by a catalyst. This process is called transesterification. From an environmental point of view, the use of biodiesel has several advantages such as reducing carbon dioxide emissions, being non-toxic and biodegradable. Kapok seed oil has potential for exploitation, particularly as a raw material for the manufacture of biofuel. Kapok seeds (Ceiba pentandra) have the potential to be used as a feedstock for biodiesel because their oil content is quite high, around 18-25% oil. The controlled combustion of rice husks produces ash containing high purity amorphous silica. Amorphous silica can be obtained from RHA (rice husk ash) when rice husk is burned at a temperature of 700°C, and it is transformed into crystalline silica when burned at a temperature above 850 °C. This silica has many applications as a filler, adsorbent, catalyst support, star gel component and source for the production of premium silicon and its compounds. The aim of the research is to determine the transisterification process of biodiesel from kapok (Ceiba pentandra) seed oil. using a natural heterogeneous catalyst in It is an activated rice husk. The method used was the preparation of kapok seed samples and the extraction of sokhlet. Determination of free fatty acids (FFA) in kapok seed oil, activation of rice husk, manufacturing of biodiesel from kapok seed with addition of rice husk H2SO4 as catalyst. The characteristics of the biodiesel produced are Density: 859.88572 kg/m3 (SNI: 7182:2015) = 850-890 kg/m3), Viscosity: 2.45824 cSt (SNI: 7182:2015) = 2.3 – 6, 0 cSt, Calorific value: 7,374.5322 cal/g (SNI: 7182; 2015) = 7,100 -11,000 cal/ g, Devil's number: 48 (ASTM: D6751) = 47. Meanwhile, GC-MS with the highest values at all reaction times, namely Hexadec anoic acid, methyl ester (C17H34O2), methyl tetradecanoate (C15H30O2) and 9 - Octadecenoic acid (Z), methyl ester (C19H36O2) . The functional group found in kapok seeds is –OH.

Biomass nanoarchitectonics with activated rice husk char for nanoporous carbon as electrode material: Enhancing supercapacitor electrochemical performance

Nanoporous carbon from activated rice husk char was prepared via KOH activation at different ratios of rice husk: KOH, for using as electrode material in supercapacitor. The electrode could exhibit high performance in 6 M KOH aqueous electrolytes, particularly in terms of specific capacitance and power density. The Brunauer-Emmett-Teller (BET) analysis showed a high specific surface area of 2833 m²/g with a mesoporous structure in a sample activated with a 1:3 ratio of rice husk to KOH. In this sample, a high specific capacitance of 195.36 F/g was obtained at a current density of 1 A/g with excellent cycle stability of 99.87 % after continuous charge/discharge test for 10,000 cycles at 10 A/g. Furthermore, the fabricated symmetric coin cell exhibits a power density of 526.88 W/kg and an energy density of 14.77 Wh/kg. The practical application of this cell is demonstrated by its ability to power a 3 V LED light bulb for over 900 s.

Active carbon derived from rice husk as sustainable substitutes for costly platinum electrodes in dye-sensitized solar cells

Significant financial and environmental challenges are associated with using platinum electrodes as counter electrodes (CEs) in dye-sensitized solar cells (DSCs). This work uses rice husk, an agricultural waste, to create active carbon that is appropriate for DSC CEs in response to these difficulties. A simple spray pyrolysis technique created activated carbon obtained from rice husks. The DSC employing activated rice husk carbon as the CE demonstrated a conversion efficiency of 6.06%, slightly lower than the 8.21% efficiency achieved with a platinum electrode-based cell. However, this performance gap is overshadowed by the substantial cost reduction enabled by the utilization of low-cost activated carbon compared to noble metal alternatives. This result introduces promising avenues for investigating the use of agriculturally derived carbon materials as workable and affordable options for platinum CEs in DSCs, thereby contributing to the sustainable advancement of photovoltaic systems. Even though the performance of DSC that uses activated carbon derived from rice husk in CE is slightly lower than its counterparts based on platinum, the cost reduction due to the use of low-cost activated carbon with noble metal is significant.

Activated rice husk biochar for azo dye removal: batch adsorption, kinetics and thermodynamic studies

<p>The study aimed to analyze the adsorption behaviour of an activated rice husk biochar adsorbent in batch mode to expunge azo dye concentrations depletion from liquid solvents. The biochar adsorbent was formulated using different chemical synthesis processes, and its surface region was assessed using Nitrogen retention. The existence of the particular azo dyes was verified through SEM and EDX examinations. Additionally, XRD analysis was conducted to examine the intensity and crystalline structure of the activated biochar adsorbent. A batch mode study was conducted to ascertain the ideal adsorption parameters, including pH, contact time, biochar dose, and azo dye concentration. The adsorption kinetic studies supported the notion of a favourable adsorption interaction occurring through the mutual influence of the adsorbed matter and the adsorbing substrate. Most isotherm studies were well-fitted with regression values of isotherm models, indicating an adsorption process with non-uniform monolayer formation. Thermodynamic investigations validated that the binding forces between the adsorptive and the adsorbing phase are endothermic, and a significant amount of spent adsorbent was successfully recovered using a strong hydrochloric acid desorption process.</p>

Activated Rice Husk as a Heterogenous Catalyst Over Optimised Waste Cooking Oil Biodiesel Production

Activated Rice Husk as a Heterogenous Catalyst Over Optimised Waste Cooking Oil Biodiesel Production

Application of Activated Rice Husk for Adsorptive Bleaching of Groundnut Oil: Kinetic, Equilibrium and Thermodynamic Study

Kinetic, equilibrium and, thermodynamic studies of the bleaching of crude groundnut oil at optimized conditions were carried out using activated rice husk as an adsorbent for the bleaching process. The efficiency of bleaching was estimated by measuring the absorbance using a double- beam spectrophotometer at a wavelength of 450nm. The effects of adsorbent dosage, bleaching temperature and, contact time on the bleaching efficiency were studied. A directly proportional relationship was found between dosage and contact time and the bleaching efficiency while a bell curve was discovered for temperature increase. The surface area of the rice husk increased from
 150.32 to 1450.32 m2/g while the pore volume decreased from 0.15524 to 0.12844 cm3/g after activation which was determined via a Brunauer-Emmet-Teller (BET) analysis and the results further validated by the Scanning Electron Microscopy (SEM) images obtained. The kinetic data of the bleaching process were best described by the pseudo-second order kinetic model while the equilibrium adsorption isotherm analysis showed that the results from the Temkin isotherm were the most significant. The thermodynamic study revealed that the adsorptive bleaching process is feasible, spontaneous and, exothermic with a decrease in entropy. The enthalpy value also showed that the adsorption process is predominantly physisorption. This study has revealed that an effective adsorbent can be produced from rice husks under optimized process conditions.

Transesterification of biodiesel from kapok seed oil (ceiba pentandra) using a natural heterogeneous katalyst (rice husk activation)

Biodiesel as a renewable energy source can be produced by a chemical reaction between vegetable oil or animal fat and short-chain alcohol such as methanol, ethanol or buthanol and is supported by a catalyst. This process is called transesterification. From an environmental point of view, the use of biodiesel has several advantages such as reducing carbon dioxide emissions, being non-toxic and biodegradable. Kapok seed oil has potential for exploitation, particularly as a raw material for the manufacture of biofuel. Kapok seeds (Ceiba pentandra) have the potential to be used as a feedstock for biodiesel because their oil content is quite high, around 18-25% oil. The controlled combustion of rice husks produces ash containing high purity amorphous silica. Amorphous silica can be obtained from RHA (rice husk ash) when rice husk is burned at a temperature of 700°C, and it is transformed into crystalline silica when burned at a temperature above 850 °C. This silica has many applications as a filler, adsorbent, catalyst support, star gel component and source for the production of premium silicon and its compounds. The aim of the research is to determine the transisterification process of biodiesel from kapok (Ceiba pentandra) seed oil. using a natural heterogeneous catalyst in It is an activated rice husk. The method used was the preparation of kapok seed samples and the extraction of sokhlet. Determination of free fatty acids (FFA) in kapok seed oil, activation of rice husk, manufacturing of biodiesel from kapok seed with addition of rice husk H2SO4 as catalyst. The characteristics of the biodiesel produced are Density: 859.88572 kg/m3 (SNI: 7182:2015) = 850-890 kg/m3), Viscosity: 2.45824 cSt (SNI: 7182:2015) = 2.3 – 6, 0 cSt, Calorific value: 7,374.5322 cal/g (SNI: 7182; 2015) = 7,100 -11,000 cal/ g, Devil's number: 48 (ASTM: D6751) = 47. Meanwhile, GC-MS with the highest values at all reaction times, namely Hexadecanoic acid, methyl ester (C17H34O2), methyl tetradecanoate (C15H30O2) and 9 - Octadecenoic acid (Z), methyl ester (C19H36O2) . The functional group found in kapok seeds is –OH.

Predicting the Strength Performance of Hydrated-Lime Activated Rice Husk Ash-Treated Soil Using Two Grey-Box Machine Learning Models

Geotechnical engineering relies heavily on predicting soil strength to ensure safe and efficient construction projects. This paper presents a study on the accurate prediction of soil strength properties, focusing on hydrated-lime activated rice husk ash (HARHA) treated soil. To achieve precise predictions, the researchers employed two grey-box machine learning models—classification and regression trees (CART) and genetic programming (GP). These models introduce innovative equations and trees that readers can readily apply to new databases. The models were trained and tested using a comprehensive laboratory database consisting of seven input parameters and three output variables. The results indicate that both the proposed CART trees and GP equations exhibited excellent predictive capabilities across all three output variables—California bearing ratio (CBR), unconfined compressive strength (UCS), and resistance value (Rvalue) (according to the in-situ cone penetrometer test). The GP proposed equations, in particular, demonstrated a superior performance in predicting the UCS and Rvalue parameters, while remaining comparable to CART in predicting the CBR. This research highlights the potential of integrating grey-box machine learning models with geotechnical engineering, providing valuable insights to enhance decision-making processes and safety measures in future infrastructural development projects.

Production of reduced graphene oxide from activated rice husk charcoal using a high-energy ball milling method

Production of high-quality graphene at a commercial scale with low cost remains challenging. Thus, we used a high-energy ball milling approach to make reduced graphene oxide (rGO) from activated rice husk charcoal as an enriched carbon source. The as-produced rGO samples were characterized to determine the effect of various milling times (0, 50, 100, 150, and 200 min) on their structure, morphology, specific surface area, pores volume, and size distribution. The variation in the ball milling times was found to introduce the structural defects and remove the oxygen functional groups, thus improving the overall characteristics of the obtained rGO. The wrinkle sheet-like structures of rGO evolved into numerous paper balls-like transparent rumple morphologies due to the milling process-enabled compression mechanism. In addition, due to the increase of milling times, the amount of carbon in rGO was increased to 89.9 atomic%, and oxygen was reduced to 9.3 atomic%, wherein the thermal agitation-mediated collisions of particles played a significant role. The specific surface area (121.483 m2 g−1) and pore volume (0.133 cm3 g−1) of rGO prepared at a milling time of 50 min were observed to be optimum. It was asserted that a high-energy ball milling technique with controlled milling times could help produce high-quality rGO from activated rice husk charcoal at low cost, leading to the development of sustainable and environmentally friendly material required for diverse applications.

Use of activated rice husk biochar for the removal of metals and microorganisms from treated leachates from landfills

Use of activated rice husk biochar for the removal of metals and microorganisms from treated leachates from landfills

Effect of Adsorbent from Activated Rice Husk Charcoal on The Characteristics of Crude Palm Oil (CPO); A Preliminary Study

The quality of crude palm oil (CPO) needs to be considered to ensure the food safety of further processed products. Several characteristics of CPO such as water content, free fatty acids, Cl, and Fe are known to be precursors for the formation of toxic compounds such as 3-Mono Chloro-1,2-Propane-Diol (MCPD) in further processed products. A study was conducted to determine the effect of activated rice husk charcoal used as an adsorbent in improving the quality of CPO. The activation process includes immersion in potassium hydroxide and sodium chloride solutions, washing to neutral pH (pH 7), filtering, and burning using a furnace at 300°C for 2 hours. The activated husk charcoal was then reduced its size into 100 mesh. The activated husk charcoal was then applied to CPO by adding 1% to the CPO, then heated until it reaches temperature of 50 and 60°C followed by stirring for 30 and 60 minutes, then deposited for 10 minutes before it was filtered. The results showed that the adsorbent obtained through the activation process using potassium hydroxide with a contact time of 60 minutes on CPO could reduce free fatty acids up to 21.87%, Fe 31.97%, moisture content 96,3% and Cl 91.15%. The application of activated husk charcoal on CPO also showed a significant effect on the water content, viscosity, and color of CPO. These results can be used as an alternative treatment for handling CPO in reducing the formation of toxic compounds such as 3-MCPD in CPO-derived food products.

Application of rice shell activated carbon for reduction of chemical oxygen demand limit and adsorption of iron from abattoir wastewater

In this investigation, rice shell (RS)-activated carbon (AC) - (RS-AC) is used as a bio-sorbent to reduce chemical oxygen demand (COD) and adsorb iron from effluent from an abattoir. With H3PO4, the rice husk was altered and chemically activated. Scan electron microscopy (SEM) as well as Fourier-Transform-Infrared (F-T-IR) were utilized to examine the activated RS and examine its content, appearance, and structure. Moreover, proximate analytical study was used to ascertain the activated rice husk's wetness, volatile matter, ash, bulk density, and fixed carbon contents. Contact period, temperature, and dosage are the adsorption parameters that are assessed. The contact period of 10, 20, 30, 40, 50, and 60 min, the dosage of 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6g, and the temperature of 20, 40, 60, 80, and 100oC were evaluated for the Fe bio-adsorption as well as COD limits reduction in wastewater obtained from abattoir at constant agitation of 200rmp and potential hydrogen level of 5 for all the runs. RS-AC can be used to maintain the amount of iron and COD in aqueous solutions and water treatment, according to the results. According to this investigation, ARH has a high fixed carbon content, which makes it an efficient bio-adsorbent, and the resulting RS-AC has a good bulk density for flow consistency. The FI-M best matches the linear equation for iron removal, whereas the LI-M given that the coefficient of correlation that well matches the equation to have COD limit at acceptable level. In comparison to other models, second ordered Kinetics model-SOKM satisfactorily describes current data to keep Fe as well as COD levels within standard ranges; as a result, chemical adsorption controls the bio-adsorption process.

Bacteriological and Physicochemical Assessment of Treated Petroleum Effluent Obtained from Some Petrochemical Industries in Warri, Nigeria Using Activated Rice Husk

Bacteriological and Physicochemical Assessment of Treated Petroleum Effluent Obtained from Some Petrochemical Industries in Warri, Nigeria Using Activated Rice Husk

Removal of Phenol from Olive Mill Wastewater Using Activated Rice Husk

<p>Olive mill wastewater (OMWW) contains many phenolic compounds that if discharged without proper treatment, may lead to substantial risks to human health and deterioration of the environment and aquatic systems. In this study, an attempt was made to produce activated carbon from Rice Husk (RH). The RH was chemically activated by calcium chloride and was utilized for the removal of phenol from the aqueous solution. The removal efficiency using the Activated Rice Husk (ARH) was investigated at different variables such as pH, contact time, adsorbent dose, initial concentration, and carbonization temperature. Results showed that the optimum removal efficiency was 91.62% which was achieved at pH=6, carbonization temperature=850 ˚C, and after 4hrs contact time. Adsorption isotherm fitted well to Langmuir and Freundlich isotherm models while the kinetic data fitted well to the pseudo-second-order model, and thermodynamic data showed that the adsorption is endothermic in nature. Then the activated rice husk sample was used for phenol removal from real OMWW samples from different locations in the city of Irbid-Jordan providing average removal efficiency reached 94.6%. The study indicates that RH and ARH have good potential to be used for phenol removal.</p>

Numerical Investigation on Flexural Behaviour of Alkali Activated Rice husk Ash Based Concrete

Numerical Investigation on Flexural Behaviour of Alkali Activated Rice husk Ash Based Concrete

Facile fabrication of NiCo-LDH on activated rice husk carbon for high-performance all-solid-state asymmetric supercapacitors

NiCo-LDH@RHC electrode material was prepared by calcination and hydrothermal method from rice husk. The nanoflower structure provides more active sites, promotes ion diffusion, and therefore has excellent specific capacitance and cycling properties.

Study on the equilibrium and kinetics of nickel adsorption on rice husk: the role of activation

Rice husk is an agricultural byproduct that is produced in huge quantities during the rice milling process. Following the trend of utilizing agricultural waste, rice husk is activated by many activators to synthesize heavy metal ion adsorbent materials. This work presents the results of the study on the adsorption of nickel ions (Ni2+) by activated rice husks. The husk was activated by three agents (NaOH, acetic acid, and H2O2), which removed 73.29 percent of the hemicellulose and 60.25 percent of the ligin (calculated by the Chesson-Datta method). The influence of time on the adsorption capacity of Ni2+ ions of activated rice husks was carried out with an initial concentration of Ni2+ ions of 160mg/L and a pH of 5.5. The concentration of adsorbent was 1,0 g.L-1. After 80 minutes of adsorption, the equilibrium adsorption capacity reached 33.33 mg.g-1. The maximum adsorption capacity calculated by the Langmuir adsorption model was 57.46 mg.g-1. Three kinetic models (Lagergren's apparent first-order kinetics, second-order apparent kinetics and Webber-Morris internal diffusion kinetics) were also studied and analyzed.

Application of Renewable Natural Materials for Gas and Water Shutoff Processes in Oil Wells

We propose a complex sealing compound for increasing the efficiency of shutoff operations based on natural materials processing for materials such as sand, peat, rice, and husks. We studied the influence of mechanical activation processes on the mechanical and rheological properties of the developed sealants. Through mechanochemical activation, sand dissolution in a low-concentrated alkali solution was possible, and gelling the resulting sodium silicate while reinforcing it with undissolved sand particles to obtain a sealant composition. We used this approach to produce a hybrid sealing compound based on activated rice husks with up to 20% biogenic silicon dioxide combined with mechanically activated peat: the maximum shear strain of the hybrid sealant was 27.7 ± 1.7 Pa. We produced hydrogels based on sodium silicate, polyacrylamide, and chromium acetate, reinforced with mechanically activated rice husks. We studied the sealants’ rheological and filtration properties and observed the respective viscoplastic and viscoelastic properties. An increase in the dispersion concentration from 0 to 0.5% increased the maximum strain value of undestroyed hydrogel’s structure in the range 50–91 Pa and the maximum shear strain from 104 to 128 Pa. The high residual resistance factor values of the ideal fracture model make the natural and plant-renewable raw materials very promising for repair and sealing work.

A Novel Conjugate Mechanism for Enhancing the Adsorption Capacity of Amine-Functionalized Activated Rice Husk Ash for Simultaneous Removal of Organics and Anions in Wastewater: Experimental and Theoretical Explanations.

In this study, amine-functionalized rice husk ash (TRI-ARHA) was prepared and successfully applied as a multipurpose adsorbent for simultaneous removal of organics (i.e., methyl orange, MO), nitrate, and phosphate in wastewater with adsorption capacities of around 16.6 mgMO/g, 32.9 mgNO3–-N/g, and 13.4 mgPO43–-P/g. These capacities were superior to those of the other commercially available materials such as activated carbon and ion-exchange resins in both individual and multipollutant adsorption experiments. In addition, the simultaneous adsorption of three components gives a higher adsorption capacity than individual adsorption for each anion (e.g., 1.18 times for nitrate and 1.11 times for phosphate). A conjugated adsorption mechanism may occur on the surface of the TRI-ARHA material, which can be ascribed to the amine groups in the MO molecule that are further activated by H+ (released from the surface amine groups) or Na+ ions (present in the solution), to form new adsorption centers for nitrate and phosphate. The integration process of H+ and Na+ to the nitrogen positions of MO was also studied by computational chemistry with the basis set of B3LYP/6-32G* calculated by Gaussian 16 software. The application in the treatment of real wastewaters proved that the TRI-ARHA material was more advantageous for multipollutant removal than other materials, thanks to its conjugated adsorption mechanism.

Preparation of rice husk hydrochar as an atrazine adsorbent: Optimization, characterization, and adsorption mechanisms

This study aims to develop rice husk hydrochar as an alternative adsorbent for application in atrazine removal. Hydrochar was obtained by microwave-assisted hydrothermal carbonization under different conditions: temperature (150 – 200°C), residence time (20 – 60 min), and liquid to solid ratio (5:1 – 15:1 mL g-1). Surface activation of hydrochar was conducted using various concentrations of KOH and H2O2. The results indicated that hydrochar prepared at higher temperatures, lower liquid to solid ratios, and longer residence times had significantly higher atrazine adsorption capacities. Atrazine adsorption by pristine and activated hydrochars could be best fitted to the pseudo-second-order and Freundlich models. The adsorption capacity of KOH-activated hydrochar was the highest (4.06 mg g-1), which is even greater than that of biochar with higher surface areas. The results of FTIR and XPS demonstrated that activated rice husk hydrochars contained abundant oxygen functional groups, which played a dominant role in atrazine adsorption via hydrogen-bonding interaction.