Rice Husk Ash Content Research Articles

The potential of rice husk ash for silica synthesis as a semiconductor material for monocrystalline solar cell: a review

The solar cell is a device that can convert solar energy into electrical energy. The solar cell is promising energy because it is environmentally friendly compared to fossil fuel. The essential component in the solar cells is silicon. Silicon is a semiconductor that can absorb sunlight. However, the available solar cells currently have relatively high prices since the semiconductor compiler material requires many processes and expensive. Rice husk ash can be used as a producer of environmentally friendly silicon at affordable prices. The rice husk could produce 87-97% silica and 16-25% ash. In general, the silica content of rice husk ash is 94-96%. The processes for producing silica material as a semiconductor were, such as rice husk ash preparation, greying, leaching, making silicon by reduction, and conductivity test. This review aimed to provide insight into converting the rice husk ash to solar cells.

Production of eco-friendly concrete incorporating rice husk ash and polypropylene fibres.

The use of supplementary cementitious materials (SCMs) has increased over the years due to the carbon footprint associated with the production of cement, which contributes to 10% of the total globalCO2 gas emissions. This causes an increase in global warming, and the exponential increase in demand for construction of concrete has caused depletion of natural resources. Furthermore, due to increased urbanisation, large quantities of agro-industrially processed waste materials are generated and dumped into landfills, causing significant land scarcity, environmental issues, and pollution. Therefore, it has become necessary to reduce the CO2 emissions by reducing our dependency on cement as a binder and developing eco-friendly concrete using alternative binders from agro-industrial waste materials. This study utilises Rice Husk Ash (RHA) as SCM and reinforcing with polypropylene (PP) fibres. The cement content is replaced with 5 to 20% RHA with an increment of 5% while reinforcing with PP fibres ranging from 0.20 to 0.30%. Based upon the results, it can be observed that concrete incorporating 15% RHA and reinforced with 0.25% PP fibres achieved better performance than the specimen with no SCM. However, a further increase in RHA content decreased concrete strength, which could not be recovered entirely with the reinforcement of PP fibres, though concrete with higher (20%) RHA reinforced with PP fibres could be used for non-structural and low-cost construction.

Plastic Waste Conversion Reinforced with Rice Husk Ash and Red Stone Powder as Partial Sand Replacement for Paving Blocks Production

The conversion of plastic waste into economically valuable materials is an innovative way to reduce plastic waste in the environment. At the present study aimed to assess the compressive strength and water absorption capacity of paving blocks from plastic waste combined with rice hausk ash as sand partial replacement and red stone powder as its natural colorant. The speciment were casted in a 6 x 6 x 6 cm mold and pressed with a load of 6 tons using a mechanical pressing machine. The compressive strength and water absorption of paving block at different content of plastic powder and rice husk ash were investigated. The study revealed that paving blocks made by replacing sand with 40% of plastic powder and 5% of rice husk ash pigmented with red stone at the ages of 28 days have compressive strengths of 12.7 MPa with water absorption value of 3.75%. We recommend this paving block was suitable for non-traffic areas such as pedestrians, landscapes, and public walkways.

Influence of High Volume RHA on Properties of Cement Mortar

This work study the impact of partial cement replacement by high volume Rice Husk Ash (RHA) on some characteristics of cement mortar like compressive strength and flexural strength at different ages. In this research, RHA was used in three different ratios (20, 40, and 60)% as a cement substitution and the findings were compared with control mixture (0% RHA). The findings demonstrated that the replacement of cement by RHA reduced the compressive strength of all selected ratios and the increase in the content of RHA lead to reduce compressive strength comparative to control sample with 100% cement as a binder at all ages. However, the flexural strength results indicated that the RHA in 20% showed approximately same results as control sample at early ages while increasing the curing period lead to improve flexural strength. Increasing RHA higher than 20% lead to decrease Flexural strength at all selected ages.

A new eco-friendly and low cost additive in water based drilling fluids

This study investigates the possibility of using rice husk ash as an additive to develop an environmentally friendly and low-cost drilling fluid system. The rice husk ash was added as an additive to water-based bentonite drilling fluids at different concentrations ranging from 2 wt% to 15 wt%. Rheological and filtration properties of each drilling fluid developed were measured by using a viscometer and standard low-pressure low-temperature filter press. Subsequently, cutting carrying index, minimum annulus velocity required to clean bottom of the well efficiently, flow behaviour index and permeability of mud cakes of the formulated systems were calculated in order to assess performance of the systems. The results demonstrated that the rheological and properties were improved depending on concentration of rice husk ash introduced. With the introduction of 15 wt% concentration of rice husk ash, while apparent viscosity and yield point increased by 60% and 183%, respectively, thixotropy and plastic viscosity decreased by 29% and 63%, respectively. On the other hand, drilling fluid with 4% wt% content of rice husk ash reduced the fluid loss by 10%. Moreover, results showed that cutting carrying index, minimum annulus velocity required to clean bottom of the well efficiently and flow behaviour index of the enhanced with the exploitation of rice husk ash in the drilling fluid. This study showed that rice husk ash as a promising additive to use in the water-based bentonite drilling fluids when properly implemented, and hence reducing the impact on the environment, and the total cost for drilling.

Potential of alternative waste materials: rice husk ash and waste glass cullet with boric acid addition for low-fired unglazed tiles

This study aimed to investigate the potential of utilizing waste materials by adding boric acid (H3BO3) for producing low-fired unglazed tiles under low temperatures. Eighteen formulations containing rice husk ash (RHA), green glass cullet (GGC), and local kaolin clay (LKC) were constructed and divided into three groups with different RHA contents of 0, 10, and 20 wt%. Boric acid was also added with three amounts of 0, 2, and 3 wt% in mixtures. Specimens of these mixtures were produced by uniaxial pressing at 10 MPa and then fired at 900 o С for 1 h. The results showed that the formula of group B contained 10 wt% RHA, 60 wt% GGC, and 30 wt% LKC with the addition of 2 wt% boric acid. Moreover, the formula of group C contained 20 wt% RHA, 50 wt% GGC, and 30 wt% LKC by adding 3 wt% boric acid. Both formulas can achieve the ISO 13006 standard of ceramic tiles in terms of modulus of rupture and water absorption. Characterization of these formulas was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and the CIELAB colorimetric coordinates. SEM results confirmed that the glassy-phase and needle-like wollastonite crystals contributed to the development of the strength and dense microstructure of fired specimens. For XRD patterns, crystalline phases, e.g., nepheline, wollastonite-1A, and calcium silicate can improve the mechanical properties of ceramic bodies. It was concluded that reutilizing RHA and GGC wastes by adding boric acid is feasible to produce eco-friendly unglazed tiles at low sintering temperature.

Influence of Rice Husk Ash on Characteristics of Earth Cement Blocks

AbstractThis paper presents an experimental study on the characteristics of earth cement blocks with Rice Husk Ash (RHA) as a partial replacement to cement. The replacement of RHA content is limited to 0%, 5%, 10%, 15% and 20% by mass of the total binder in the earth cement block. The experiments on earth cement blocks investigate the compressive strength and flexural tensile strength for mechanical properties and water absorption, sorption rate and erosion against water spray for its durability. Due to the high content of SiO2 in RHA with great reactivity, a significant increase in the compressive and flexural tensile strength of earth cement blocks was observed up to 10% RHA content. However, the durability of earth cement blocks becomes adverse with the increasing percentage of RHA replacement, but within the allowable limit. The experimental results indicate that to some extent, RHA based earth cement blocks have a significant potential for reduction in cement used in the construction industry.

In situ casting of rice husk ash in metal organic frameworks induces enhanced CO2 capture performance

Incorporation of rice-husk-ash (RHA), an agricultural waste, in situ during the synthesis of MIL-101(Cr) resulted in a significant improvement in the CO2 adsorption properties over the synthesized RHA-MIL-101(Cr). The newly synthesized RHA-MIL-101(Cr) composite exhibited an enhancement of 14–27% in CO2 adsorption capacity as compared to MIL-101(Cr) at 25 °C and 1 bar. The content of RHA incorporated in RHA-MIL-101(Cr) fine tuned the CO2 capture performance to achieve high working capacity (0.54 mmol g−1), high purity (78%), superior CO2/N2 selectivity (18) and low isosteric heat of adsorption (20–30 kJ mol−1). The observed superior CO2 adsorption performance of RHA-MIL-101(Cr) is attributed to the fine tuning of textural characteristics—enhancement of 12–27% in BET surface area, 12–33% in total pore volume and 18–30% in micropore volume—upon incorporation of RHA in MIL-101(Cr).

EFFECT OF DIFFERENT TYPES OF RICE HUSK ASH ON SOME GEOTECHNICAL PROPERTIES OF CEMENT-ADMIXED SOIL

Rice husk ash (RHA) is an agricultural residue and has shown great potential for soil stabilization. However, the research on the utilization of RHA for soft soil improvement using cement deep mixing method is still limited and the efficiency of using different RHA types for soil improvement needs to be clarified. In this study, the effect of different RHA types on Atterberg limits, unconfined compressive strength (UCS), and elastic modulus (E50) of soil-cement mixtures will be investigated. Two types of RHA which obtained from open fire burning (RHA1) and burning in a furnace under controlled conditions of temperature and duration of burning (RHA2), were used for this study. The RHA contents from 0 to 15% and 10% cement of the dry weight of the soil were used to treat the soft soil. The research results show that the types of RHA insignificantly affect the change in Atterberg limits of cement-admixed soil. Regarding the soil strength, the RHA2 shows a higher efficiency in the enhancement of treated soil strength at 28 days of curing than the RHA1. The addition of 12% RHA2 to the cement-admixed soil can increase the UCS and E50 values of treated soil by more than 50%.

Innovative substrates for sugarcane seedling production: Sewage sludges and rice husk ash in a waste-to-product strategy

Recent advances in the sucroenergy production chain include a new way of planting sugarcane based on a method of seedling propagation which requires a significant amount of substrate. Since the sucroenergy sector has been noted as having cleaner energy production, it is imperative that sustainable substrates suitable for the production of sugarcane seedlings be developed. Therefore, the main objective of this study was to develop innovative substrates with solar-dried sewage sludges and rice husk ash to compose substrates for sugarcane seedling production. Batches of sewage sludges were collected in open drying beds from three different municipal wastewater treatment plants from the Rio Grande do Sul State, Brazil: from Passo Fundo city (treated by anaerobic digestion), from Rio Grande city (aerobic digestion) and from Santa Maria city (aerobic digestion). Rice husk ash was obtained from a rice processing industry in the Pelotas industrial region in southern Brazil. The content of trace elements and the pathogenicity of pure sewage sludge (SS) were analyzed. The nutrient content of SS and rice husk ash (RHA) was determined. Twelve substrates with differing ratios of SS, RHA, and vermiculite were formulated to evaluate the subsequent development of sugarcane seedlings. Chemical and physical attributes were determined in all substrates and compared to a commercial substrate. The experiment was conducted in a greenhouse using mini-setts of sugarcane of the RB867515 genotype. Fifteen days after planting the seedlings were evaluated for stalk diameter, shoot height, shoot dry weight and root, and the Dickson quality index was determined. Sewage sludge showed low levels of heavy metals and pathogenic organisms and high contents of nutrients, especially nitrogen, phosphorus and micronutrients such as Zn and Cu, showing promising suitability as a substrate component for seedling production. In general, substrates of all tested proportions of SS and RHA promoted greater shoot and root dry weight and a superior Dickson Quality Index than the commercial substrate used as reference, except for the formulation containing 87.5 % SS. The viability of combining sludges from municipal wastewater treatment plants and rice husk ash into one product was confirmed using a set of biometric attributes and nutrient tissue contents obtained from the production of sugarcane seedlings.

Early Age Shrinkage Behavior of Triple Blend Concrete

The early age shrinkage is responsible for the early age cracking of concrete. It is very critical for durability of concrete. The change in volume of concrete due to evaporation of water or dehydration process is known as shrinkage. To reduce the early age shrinkage utilized the supplementary cementitious material (SCM) in concrete. In present research industrial and agricultural waste byproduct like fly ash (FA) and rice husk ash (RHA) along with cement were used as SCM. The triple blend concrete was prepared by the combination of 20%, 30% and 40% partial cement replacement with FA and RHA for 0.30, 0.35 and 0.40 water-cement ratio. The concrete samples were tested by advanced instrument as shrinkage cone meter were used for measure the shrinkage. The result shows that the early age shrinkage reduced with increasing the SCM content. The microstructure characteristics enhanced with raising the content of FA and RHA up to 30% replacement; that was due to the dense particle packing.

Effect of Polypropylene Fibre on the Strength of Concrete Incorporating Rice Husk Ash

Abstract The increase in Carbon Dioxide (CO2) gas emissions during the production of cement have increased the necessity for the development of eco-friendly sustainable concrete using alternative binders. This research was conducted to study the strength behaviour in terms of compressive and flexural strength of concrete incorporating rice husk ash (RHA) as a supplementary cementitious material. RHA is a potential alternative binder due to its pozzolanic nature but it can partially replace cement to a certain amount, beyond it, the strength decreases making the concrete less viable. Therefore, to strengthen RHA-based eco-friendly concrete, Polypropylene (PP) fibres were used to reinforce concrete. Based on the results, it was observed that 5% RHA achieved higher strength than the control sample, however, a further increase in RHA content resulted in a significant decrease in strength. Concrete with 10% RHA which showed reduced strength was reinforced with PP fibres which resulted in a gain in strength.

PREDICTION OF CALIFORNIA BEARING RATIO OF FINE-GRAINED SOIL STABILIZED WITH ADMIXTURES USING SOFT COMPUTING SYSTEMS

The main focus of this study was to predict California bearing ratio (CBR) of stabilized soils with quarry dust (QD) and lime as well as rice husk ash (RHA) and lime. In the laboratory, stabilized soils were prepared at varying mixing proportions of QD as 0, 10, 20, 30, 40 and 50%; lime of 2, 4 and 6% with varying curing periods of 0, 7 and 28 days. Moreover, admixtures of RHA with 0, 4, 8, 12 and 16%; lime of 0, 3, 4 and 5% was used to stabilize soil with RHA and lime. In this study, soft computing systems like SLR, MLR, ANN and SVM were implemented for the prediction of CBR of stabilized soils. The result of ANN reveals QD, lime and OMC were the best independent variables for the stabilization of soil with QD, while, RHA, lime, CP, OMC and MDD for the stabilization of soil with RHA. In addition, SVM proved QD and lime as well as RHA, lime, CP, OMC and MDD were the best independent variables for the stabilization of soil with QD and RHA, respectively. The optimum content of QD was found 40% and lime 4% at varying curing periods to get better CBR of stabilized soil with QD and lime. Moreover, the optimum content of RHA was also found 12% and lime 4% at varying curing periods to get better CBR of stabilized soil with RHA and lime. The observed CBR and selected independent variables can be expressed by a series of developed equations with reasonable degree of accuracy and judgment from SLR and MLR analysis. The model ANN showed comparatively better values of CBR with satisfactory limits of prediction parameters (RMSE, OR, R2 and MAE) as compared to SLR, MLR and SVM. Therefore, model ANN can be considered as best fitted for the prediction of CBR of stabilized soils. Finally, it might be concluded that the selected optimum content of admixtures and newly developed techniques of soft computing systems will further be used of other researchers to stabilize soil easily and then predict CBR of stabilized soils.

Sustainable use of rice husk ash in cement-based materials: Environmental evaluation and performance improvement

The feasibility of using agricultural waste of rice husk to prepare highly reactive rice husk ash for sustainable cement-based material was explored through five sets of procedures: optimization of rice husk ash with an improved combustion technique, pozzolanic activity evaluation of the prepared rice husk ash, strength development of mortar with rice husk ash, sulfate attack experiment to investigate the potential durability, and environmental evaluation of rice husk ash utilization. From the results, the optimum rice husk ash using improved combustion technique had high pozzolanic activity, it presented the highest lime-ash compressive strength, a violent pozzolanic reaction heat flow as well as rapid Ca(OH)2 consumption ability among different mineral additives. Compressive strengths of mortars have been enhanced with the increase of rice husk ash contents. The results of sulfate attack indicated that paste with 15% rice husk ash improved sulfate resistance by stabilization of C–S–H and the refinement of pore structure. Sustainability analysis including embodied carbon dioxide emission and energy consumption confirmed the environmental friendliness of rice husk ash utilization. This study verified the feasibility of highly reactive rice husk ash from agricultural waste and the potential utilization of it as sustainable mineral admixture in cement-based materials.

Rice Husk Ash and Fly Ash Effects on the Mechanical Properties of Concrete

Cement production involves high amounts of energy consumption and carbon dioxide emissions. Pakistan is facing a serious energy crisis and cement’s cost is increasing. In addition, landfilling of potential concrete components can lead to environmental degradation. The use of waste as cement replacement not only reduces cement production cost by reducing energy consumption, but it is also environmentally friendly. The purpose of this study is to analyze the characteristics of concrete by partially replacing cement with Rice Husk Ash (RHA) and Fly Ash (FA). This study is mainly focused on the performance of concrete conducting a slump test, and investigating indirect tensile and compressive strength. Cement was replaced with RHA and FA by 5% (2.5% RHA + 2.5% FA), 10% (5% RHA + 5% FA), 15% (7.5% RHA + 7.5% FA) and 20% (10% RHA+10% FA) by weight. Ninety concrete samples were cast with mix proportions of 1:2:4 and 0.55 water/cement ratio. Cube and cylindrical samples were used for measuring compressive and split tensile strength respectively, after 7 and 28 days. The results showed that after 28 days, the 5% RHA+5% FA sample’s compressive strength was enhanced by 16.14% and its indirect tensile strength was improved by 15.20% compared to the conventional sample. Moreover, the sample’s slump value dropped as the content of RHA and FA increased.

Hydrochloric Acid Pretreatment of Different Types of Rice Husk Ash Influence on the Properties of Cement Paste.

When properly processed, rice husk ash (RHA) comprises a large amount of SiO2, which exhibits a high pozzolanic activity and acts as a good building filler. In this paper, the effects of rice husk ash content, acid pretreatment, and production regions on the compressive and flexural properties and water absorption of a cement paste were studied. The experimental results showed that the compressive strength of the rice husk ash was the highest with a 10% content level, which was about 16.22% higher than that of the control sample. The rice husk after acid pretreatment displayed a higher strength than that of the sample without the acid treatment, and the rice husk from the Inner Mongolia region indicated a higher strength than that from the Guangdong province. However, the flexural strength of each group was not significantly different from that of the blank control group. The trend observed for the water absorption was similar to that of the compressive strength. The variation in the RHA proportions had the greatest influence on the properties of the paste specimens, followed by the acid pretreatments of the rice husks. The production regions of the rice husks indicated the least influence.

Optimization of sisal fibre and rice husk ash usage on lateritic soil for construction of roadway

In the construction field, various stabilization techniques prevail that deploy diverse natural and synthetic materials. In the present study, the viability of utilizing sisal fibre (SF) and waste material, i.e. rice husk ash (RHA) on the properties of lateritic soil for construction of roadways have been investigated. Different geotechnical tests like Unconfined Compressive Strength (UCS) test, Compaction test and preliminary test are being performed on the 21 samples with different proportions prepared for the research work. It has been determined that the maximum dry density (MDD) is found to be 1.94 mg/m3 for the virgin soil at 20% RHA and 30% SF content and decreased to 1.70 mg/m3 when RHA and SF content were 0% and 30% respectively. Also, there was an increment of 116 kN/m2 for virgin soil to 145 kN/m2 when SF and RHA content were 40% & 10% respectively; even there was an increment of optimum moisture content (OMC) from 10.83% to 20.83% at 0% RHA and 30% sisal fibre content. Hence, the admixtures reinforced with soil will enhance the engineering properties of lateritic soil and providing an economical as well as eco-friendly method of soil stabilization.

Studying the Properties of SBS/Rice Husk Ash‐Modified Asphalt Binder and Mixture

Sustainable materials in the field of road pavement have become a research direction in recent years. In this study, the rice husk ash with small dosage of styrene‐butadiene‐styrene (SBS) was added as a bioadditive into the base asphalt to modify its properties. Different contents (0, 2, 5, 10, and 15%) of rice husk ash (RHA) and 1% of SBS were selected to prepare the modified asphalt. Penetration, softening point, ductility, rotational viscosity test, and temperature sweep test were conducted to investigate the properties of SBS/RHA‐modified asphalt binder. Rutting test, moisture susceptibility, and low‐temperature cracking were utilized to evaluate the performances of SBS/RHA‐modified asphalt mixture. The results showed that the penetration decreased and the softening point and rotational viscosity enhanced while the ductility slightly decreased with the incorporation of rice husk ash. The SBS/RHA‐modified asphalt mixture had better high‐temperature performance than that of the virgin asphalt mixture but slightly lower moisture stability and low temperature performance. The tensile strength ratio of the virgin and modified asphalt mixture met the requirement of specification. The tensile strain of mixture SR15 was lower than the requirement for the asphalt mixtures on the basis of the specification. For the SBS/RHA‐modified asphalt binder based on the comprehensive properties, the content of rice husk ash should not be higher than 15%.

Effect of Partial Replacement of Ordinary Portland Cement (OPC) with Ghanaian Rice Husk Ash (RHA) on the Compressive Strength of Concrete

The cost of cement has made concrete production expensive such that the housing deficit in developing countries is on the rise despite all the efforts by governments and other stakeholders to produce affordable housing units for the populace. Ashes of agricultural products such as rice husk, known as mineral admixtures may have pozzolanic characteristics which would be more beneficial to the housing industry in terms of strength gain and economy than being pollutants to the environment. Rice Husk Ash (RHA), because of its finely divided form and very high silica content and amorphousness, proved to be useful for strength gain of Rice Husk Ash Concrete (RHAC). Rice husk ash was manufactured by uncontrolled burning, ground, sieved and replaced with cement at 0%, 5%, 10%, 15%, 20% and 25% in mass for the mixes C20, C25, C30 and C35 where their compressive strengths were verified at 3, 7, 14, 21, 28, 56, 90 and 180 days. The X-ray diffraction pattern list indicated amorphous as well as diffused peak of about 8000 counts of SiO2 representing crystalline structures identified as cristobalite. A physical examination of the RHA showed very fine appearance, grey color and specific gravity of 2.06. The chemical analysis also revealed the existence of oxide content to be 55.8% representing 0.78% of Fe2O3, 54% of SiO2 and 1.06% of Al2O3 representing 20.23% lower than the minimum value of 70% required for pozzolans. Generally, the compressive strength values decreased as the RHA content in the mixes increased but when compared to the control concrete the optimum replacement percentage of Ordinary Portland Cement (OPC) with RHA at 5% showed an increase above the control concrete for C20 mix. The increase in the RHA in the mixes resulted in the high demand for water in all the mixes.

Effects of ultra fine slag as mineral admixture on the compressive strength, water absorption and permeability of rice husk ash based geopolymer concrete

Geopolymer concrete (GPC) is a sustainable green concrete, replaces ordinary Portland cement concrete prepared by activating aluminosilicate based industrial waste materials with an alkaline solution as an alkaline activator. In this paper rice husk ash (RHA) based GPC was prepared with varying the percentages of ultra-fine slag (UFS) and RHA, activated with an alkaline mixture of sodium hydroxide and sodium silicate with desired proportion. The ambient curing method was used at an average temperature of 27-degree Celsius. The compressive strength, the durability property of GPC in terms of water permeability and water absorption were investigated. Effects of several parameters such as the percentage of ultrafine slag, duration of curing, RHA content on water permeability, and water absorption of geopolymer concrete was studied. The result shows that the inclusion of ultra-fine slag significantly improvises the durability properties of RHA based geopolymer concrete. GPC specimens prepared with ultra-fine slag appear to have improved densification. The analysis of results shows that with a higher percentage of ultra-fine slag in rice husk ash geopolymer concrete has a substantial effect in enhancing the strength properties.