Rice Husk Combustion Research Articles

The Investigation of SiO2 structure obtained from the combustion of rice husk

In this work, SiO2 was obtained from the combustion of rice husk. The influence of temperature on its structure and morphology was investigated. At low combustion temperatures, the rice husk ash appeared to be black due to an insufficient temperature for the oxidation process. When the temperature was raised to 1000°C, the color changed to a pale pink. The elemental composition of the rice husk ash was determined by means of x-ray photoelectron spectroscopy. The survey analysis of the XPS spectra revealed the existence of Si, O, C, Ca P, K and N. The elemental fraction of Si was increased as a function of temperature. However, the N 1s XPS signal can be collected from the rice husk after the combustion at 300°C only. Si L edge XANES spectra were recorded to determine the structure of the SiO2. The results suggested the similarity between the SiO2 structure of the rice husk ash and the standard SiO2. The microstructure of the rice husk ash was studied by SEM. It was clearly seen that the pores were created on the rice husk ash. By increasing the pyrolysis temperature, the cellulosic material was removed and consequently produced channels.

Anti-friction epoxy coatings modified with rice husk

This paper discusses the use of epoxy coatings modified with rice husk ash in order to reduce abrasive wear of materials and increase their durability during operation. It was experimentally established that the rice husk ash used as a filler increases the wear resistance and hardness of epoxy coatings with a significant decrease in the coefficient of static friction. This effect occurs when using ash obtained by burning rice husk at various temperatures. It is associated with an increase in the density of the formed spatial network in the presence of the studied filler, due to the selective sorption of the components of the epoxy composition by a developed solid surface.

Effect of fire extinguish methods on RHA-concrete strength

During the few past years reuse these materials to enhancement the mechanical properties of concrete are one of the aims of concrete technology. The previous researches turn the rice hulls into rice husk ash by different methods. In this research, RHA were prepared by two methods which are oven burning at 200ºC and exposure to direct flame. Concrete cubes with 4%, 8%, 12%, and 16% by weight of cement were prepared and tested under compression test to achieve the optimum percentage of replacement and RHA preparation method. Then, three groups of RHA concrete cubes were casted and exposed to direct fire for one hour. One group of them tested directly to study the enhancement of fire resistance of RHA concrete and act of RHA in concrete fire resistance while, the other groups extinguished by two different methods (Water, and Powder) to study the effect of fire extinguish method on concrete strength. The results found that oven burning rice husk produce RHA better than direct flam. Effect of fire extinguish method has nearly the same effect on the reduction in concrete compressive strength and flexural strength. Concrete fire resistance for RHA concrete is higher than the conventional concrete.

Facile methods for the preparation of micro- and mesoporous amorphous silica from rice husk

Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in muffle at 850 °C for 2 h, (2) RH was firstly burned at 450 °C to reduce its volume. The obtained ash was refluxed with 1N HCl; after washing and drying, ash was burned at 700 °C for 3 h. (3) Un-grinded (or grinded (method 4)) RH was firstly soaked in water, treated with 1N HCl, and burned at 700 °C. (5) To utilize cellulosic fiber, RH was autoclaved with 15% NaOH, and silica was precipitated from the residual liquor. Silica hydrogel was prepared from the obtained ashes by reflux with 2.5 N NaOH followed by neutralization with 1N HCl to form silica gel. The silica gel was filtered, washed, and freeze-dried. XRF analysis confirmed the excellent removal of metal oxide impurities from RHs by acid leaching treatment. Silica precipitated from black liquor shows the most homogeneous particle size. Mesoporous silica with purity over 99% and with a homogeneous particle of average size 41.3–71.3 nm was synthesized using CTAB surfactant as the structure-directing template and RH ash as the silica source.

Study of strength characteristics of Geo-Polymer Concrete by using Rice husk Ash, Steel fiber and Quarry Dust

Environment pollution is one of the major problems faced by world today. In the field of construction industry mainly, the manufacturing of Portland cement will matter the emission of pollutants results in environmental pollution. To reduce the pollution effect on environment we can use industrial by-products in our construction industry. To produce the geo-polymer concrete the Portland cement is fully replaced with Rice husk ash and the fine aggregate is replaced with quarry dust for the binding of material alkaline liquids are used in this study. Rice husk ash is a by-product from the burning of rice husk at a temperature lower than 6000C.this means that it is in a form that is soft and easy to grind. Rice husk ash is rich in silica about 90%, 5% carbon and 2% K2O. The specific surface of RHA is between 40-100m2/g. The alkaline liquids used in this study Sodium hydroxide (NaOH) and sodium silicate (Na2Sio3). Different molarities of sodium hydroxide solution i.e. 8M and 10M are taken to prepare different mixes. The cube specimens are taken of size 150mm x 150mm x 150mm and the compressive strength is calculated for each of the mix. The geo-polymer concrete specimens are tested for their compressive strength at the age of 7days, mixes of varying sodium hydroxide molarities i.e. 8M and 10M are prepared and they are cured by direct sun-light and strengths are calculated for 7 day. The finding shows that the strength of Geopolymer concrete is increasing with the increase of the molarity of sodium hydroxide.

Water use efficiency, plant growth and vegetative traits of rubber (Hevea brasiliensis) seedlings grown using different growing media and water levels

The aim of this study was to evaluate the effects of soilless media and water levels on growth and physiological response of rubber plant. The four water levels were I50: 50%, I75: 75%, I100: 100% and I150: 150%) with three replications per water treatment and four soilless media. Water levels were determined as irrigation needed for the root zone in growing media to rise to field capacity I100:100%, at field capacity (FC). The experiment was laid out in randomized complete block design (RCBD) in factorial arrangement 3 x 4 with three replications. Soilless medium contains proportion of vermiculite, perlite, coconut husk, empty fruit bunch (EFB) compose, Christmas Island Rock Phosphate (CIRP), peat moss, urea-N and burnt rice husk coded as M1. Vermiculite, perlite, coconut husk, EFB, CIRP, peat moss, urea-N, sugarcane bagasse coded as M2. M3 is a commercial soilless medium and 100% soil was designated as control. The M1 significantly influenced almost all plant growth traits, noticeable in biomass production. Growth of plants in M1 corresponded to higher water use efficiency WUEinstantaneous and WUEintrinsic, the M1 increased plant growth like LAR, biomass production and root morphological traits. Shoot dry weight of the plant was greater (14.66 g/plant) when 150% was applied and significantly different from M2 (10.36 g/plant), M3 (4.73 g/plant) and M4 6.22 g/plant. Lower water level 50%, applied in plant grown in M1 (31.94 g/plant) recorded highest total shoot fresh weight (SFW). The results showed suitability of the soilless medium M1 and the 50% water level for rubber nursery planting. Consequently, it is recommended for planting where management and control of irrigation water are considered necessary in rubber plantation.

Growth and biomass yield of rubber seedlings grown on soilless and soil-based media

The investigation assessed the performance of rubber seedlings on different soilless media and soilbased medium. The treatments consisted of three soilless media codded M1, M2, M3 and soil-based medium M4 as a control. The highest rates of seedling growth and biomass yield were recorded in the soilless medium with 10% burned rice husk (BRH), 30% peat moss and 15% vermiculite (coded as M1) with noticeable effect in root morphological traits, while the pH and EC were 6.5 and 2.3 μS/m, respectively. Nitrogen was apparent in the M1 2.59, M2 3.03, M3 2.78 while 1.82 in M4 was recorded in the soil-based medium. Similarly, the phosphorus was noticed in M1 0.23, M2 0.26, M3 0.33, and in M4 0.13. Plant roots of rubber seedlings grown in the M1 was significantly different from the seedlings grown in M2 and M3 and M4. The least amount (5%) urea-N used was used in the best medium (M1). This amount of nitrogen could be maintained to reduce fertilizer usage. These results showed that the soilless medium that contains 10% BRH with 5% urea- N could greatly increase the growth of rubber seedlings.

Effect of Acid Leaching on Different State of Rice Husk

Rice husks (RH) are agricultural wastes available abundantly in rice producing country. A by-product obtained from combustion of rice husk is rice husk ash (RHA) which is rich in silica (SiO2) contents. This paper focused on the effect of acid leaching treatment on rice husk to produce high-purity silica. There are 4 different states of conditions involved; raw rice husk (RRH), treated rice husk (TRH), rice husk ash (RHA), and treated rice husk ash (TRHA). Citric acid; C6H8O7 was used as a leaching agent. TRH and TRHA was leached to see whether treated rice husk before combustion (TRH) or treated rice husk after combustion (TRHA) will produce more high-purity silica. Chemical composition analysis shows high amorphous silica content which is 98.47% with low metallic impurities at 1.0M C6H8O7, 70 oC for treated rice husk (TRH). X-ray diffraction (XRD) pattern shows the presence of amorphous silica in treated rice husk (TRH) and crystalline silica in treated rice husk ash (TRHA). Fragmentation of TRH into small pieces after acid leaching is seen where there is significant increase in the exposed surface areas. High-purity amorphous silica with more than 98% was prepared via citric acid leaching treatment and combustion process.

Avaliação de teor de metais pesados em cultivo de jambu (Acmella oleracea [(L) R. K Jasen]) com sedimento de viveiro de Tambaqui (Colossoma macropomum

A aquicultura tem se destacado nos últimos anos como fonte de proteína animal, porém, um de seus entraves é o descarte indevido de seus efluentes, que além de possuir resíduos orgânicos, apresenta nutrientes essenciais. O reaproveitamento desses rejeitos na agricultura pode ser uma provável saída para sanar tal problema, gerando aporte nutritivo para plantas e mitigando contaminações ao meio ambiente. O estudo objetivou avaliar a viabilidade do uso de sedimento de viveiro de produção de tambaqui para o cultivo de jambu na Região Amazônica. O experimento foi conduzido em casa de vegetação na Universidade Federal Rural da Amazônia utilizando resíduo oriundo de tanques de piscicultura. Foi constituído de cinco tratamentos, variando as concentrações de Terra preta (TP) e Sedimento de viveiro de piscicultura (SP), e acondicionado com 1kg Casca de arroz queimado (CA) para cada concentração. As concentrações foram compostas por Tratamento 1 (100% TP), Tratamento 2 (75% TP + 25% SP), Tratamento 3 (50% TP + 50 % SP), Tratamento 4 (25% TP + 75% SP) e Tratamento 5 (100% SP). O sedimento foi coletado em um viveiro de produção semi-intensivo de tambaqui e as plantas de Jambu foram irrigadas diariamente em vasos de polietileno até 79 dias após germinadas para a realização da colheita. O delineamento experimental foi inteiramente casualizado com 5 tratamentos e 10 repetições, sendo uma planta por repetição ao final do cultivo. Foram obtidos dados de Altura (ALT), Diâmetro de coleto (D), Número de folhas (NF), Clorofila (C), Área foliar (AF), Massa fresca total (MFT), Massa fresca de folha (MFF), Massa fresca de caule (MFC), Massa fresca de flor (MFFL), Massa fresca de raiz (MFR), Massa seca total (MST), Massa seca de folha (MSF), Massa seca de caule (MSC), Massa seca de flor (MSFL) e Massa seca de raiz (MSR). Os dados foram submetidos à análise de variância, sendo as equações escolhidas com base na significância dos coeficientes de regressão, a 5% de probabilidade, utilizando o software Sisvar, versão 5.6. Os tratamentos 2 (75% TP + 25% SP) e 4 (25% TP + 75% SP) foram os que apresentaram os maiores valores para a maioria dos fatores analisados. Quando analisado o comportamento linear da regressão, foi encontrado correlação positiva com as concentrações de sedimento para ALT, NF, AF, MFFL e MSFL, e os demais parâmetros apresentaram comportamento quadrático, tendo faixa ótima sempre próxima aos tratamentos 3 (50% TP + 50 % SP) e 4 (25% TP + 75% SP). A produção do jambu com resíduos de cultivo de peixe é viável haja vista o maior incremento de biomassa nas plantas submetidas a este tipo de substrato.

Integrated management of blast disease of rice

Field application of burnt rice husk ash, foliar sprays with silicon, chitosan, tricyclazole and neemazal were evaluated in possible combinations to assess the integrated effect of these combinations on leaf blast severity on susceptible variety Ratnagiri-24. Least PDI (21.85%) was recorded in treatment T5 (burnt rice husk ash @ 4 t/ha + 3 sprays of tricyclazole 75% WP @ 0.1%) followed by T2 (burnt rice husk ash @ 4 t/ha + 2 sprays of silica 5% WS @ 0.4%) (30.00%). Highest grain yield (33.37 q/ha) was recorded in treatment T5 (burnt rice husk ash @ 4 t/ha + 3 sprays of tricyclazole 75% WP @ 0.1%) followed by T2 (burnt rice husk ash @ 4 t/ha + 2 sprays of silica 5% WS @ 0.4%) (30.41 q/ha).

Effects of (Co-)Combustion Techniques and Operating Conditions on the Performance and NO Emission Reduction in a Biomass-Fueled Twin-Cyclone Fluidized-Bed Combustor

This work studied the potential of using two (co-)combustion techniques to reduce NO emission in a novel twin-cyclone combustor with a swirling fluidized bed. Prior to a (co-)combustion study, cold-state hydrodynamic tests were performed to investigate the flow regimes and hydrodynamic characteristics of a silica sand bed employed in this reactor. Static bed height of 20 cm was found suitable to ensure bubbling fluidization of the swirling bed during (co-)firing experiments. In the (co-)combustion study, rice husk (a base fuel) was first co-fired with high-moisture sugarcane bagasse (sharing 15% of the total heat input) using an air staging technique, whereas in the second group of experiments, the base fuel was combusted alone with flue gas recirculation. Detailed investigations of (co-)combustion and emission characteristics of the two proposed techniques was performed with a 100 kW heat input to the combustor for variable operating parameters: 30–60% excess air, 0–0.3 secondary-to-total air ratio in the tests for air staging, and 5– 20% fraction of the recycling flue gas when using the second technique. In all test runs, both (co-)combustion techniques ensured NO reducing conditions in the lower combustor’s chamber, leading eventually to the NO emission reduction, compared to burning the base fuel alone. At optimal operating parameters, the combustor showed high (~ 99%) combustion efficiency and reduction of NO emission: by 30% for husk-bagasse co-firing with air staging, and by 38% when burning rice husk with flue gas recirculation, as compared to conventional combustion of the base fuel.

Behavior of Metal Impurities on Surface and Bulk of Biogenic Silica from Rice Husk Combustion and the Impact on Ash-Melting Tendency

Highly pure biogenic silica can be obtained from rice husk ash if agglomeration and ash melting during combustion can be avoided. In the present study, the effects of fuel pretreatment and combusti...

Пути утилизации побочных продуктов при получении диоксида кремния из рисовой шелухи

The development of modern technologies for the use of rice husk (RH) as a raw material for the production of silicon dioxide (DC) is relevant. However, in the process of obtaining DC from RH, as a rule, solutions of acids and alkalis use. This makes it important to search for rational ways to regenerate these liquids and utilize exhaust gas emissions into the atmosphere in order to solve the problems of environmental protection. In the synthesis of DC based on RH, the following wastes are obtained: solid – carbon, liquid – solutions of hydrochloric acid and sodium oxide, exhaust gases. For utilization of the latter, it is effective to use the absorption purification method, based on the absorption by liquid reagents of toxic gases and vapors from their mixtures with air. The resulting sludge can be effectively used as a filler, in the manufacture of pavements (for example, asphalt). The resulting acidic wastewater can be used to neutralize alkaline solutions. After neutralization, in addition to discharging into the environment, these wastes can be used as chemical fertilizers (since they contain sodium chloride). Carbon can be used in the production of effective sorbents used, for example, to eliminate oil spills in environmental emergencies. Silicon dioxide obtained from rice husk is an effective filler of epoxy polymers, increasing their hardness, wear resistance and improving antifriction characteristics. It provides acceleration of the curing process and the formation of more denser cross linked structure of filled materials. The nature of the modifying action of silicon dioxide does not depend on the temperature of burning rice husk, which affects only the magnitude of the effects achieved.

Fresh Properties of Cementitious Materials Containing Rice Husk Ash for Construction 3D Printing

Combustion of rice husk produces a supplementary cementing material known as rice husk ash (RHA). Current studies on enhancement of physical properties and durability of cementitious composites with RHA are limited to applications in conventional construction. Automation in construction using additive manufacturing technique—commonly known as construction three-dimensional (3D) printing—is an emergent strategy. Because the printing process is formwork-free and requires a continuous deposition of layers with structural stability, mix design of a 3D printable concrete is different from conventional concrete. Portland cement replacement by RHA improves the sustainability of a mixture as a construction material. In this work, 20% by weight of cement is replaced with RHA. Compressive strength and workability loss of designed mixes—with and without RHA—were studied at early age and compared with fresh properties of proven printable mortar available in market. Incorporation of RHA has shown significant improvement in rheology of mortar at the rate required for construction 3D printing at large scale.

A Sustainable Route to Synthesize Graphene Oxide/Ordered Mesoporous Carbon as Effect Nanocomposite Adsorbent.

Rice husk is an agricultural waste that provides an alternative renewable source of bioenergy. Burning rice husk can produce rice husk ash. The rice husk ash is a potential resource of low-cost precursor for synthesizing high value-added materials. This paper reports the synthesis of SBA-15 mesoporous silica from recycled rice husk ash waste. Next, graphene oxide/ordered mesoporous carbon (GO/CMK-3) nanocomposite was synthesized using the SBA-15 template. The composite was investigated by X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectrometer, Raman spectrometer and surface area analyzer. Experimental results confirmed that GO/CMK-3 composite possessed high surface area (936 m²/g), large pore volume (1.077 cm³/g), and uniform pore size (4.35 nm). The mesopore structure was not destroyed by the introduction of GO. Methylene blue was employed as an adsorbate to evaluate the adsorption capacity of GO/CMK-3 composite. The GO/CMK-3 revealed much higher adsorption capacity levels than did pure CMK-3 and SBA-15. The adsorption capacity decreased with increasing solution temperature, and increasing initial concentration of dye. The thermodynamic observation indicated that the total adsorption process was spontaneous and exothermic. The conversion of rice husk ash waste into GO/CMK-3 composites can be regarded as an economically beneficial by-product for reducing environmental pollution.

Hydration Kinetics Model of Rice Husk Ash-Blended System

Rice husk ash (RHA) is a highly active pozzolanic material produced by rice husk combustion control, and it is widely used as a mineral admixture in the production of high performance concrete. The addition of rice husk ash has a complex effect on cement hydration. Current models do not explain all these complex effects. In this paper, the hydration kinetics model of RHA-cement cementitious system was established by considering the dilution effect, chemical effect and water absorption and release of porous structure of rice husk ash to composite cementitious system. Compared with the experimental results, it is proved that the model can simulate the cementitious system containing RHA-cement well. The hydration process of RHA-cement system can be used to predict the hydration degree of RHA-cement system changing with age.

Temperature and emissivity measurements from combustion of pine wood, rice husk and fir wood using flame emission spectrum

Biomass combustion for heat and power generation is one of the best ways for substituting fossil fuels. It is necessary to develop in situ temperature and emissivity measurement technology for biomass volatile flame. In this study, combustion experiments on three biomass pellets of pine wood, rice husk and fir wood were carried out in a laboratory biomass burner at two A/F flowrates. A multi-wavelength radiation thermometry method was proposed to calculate temperature and wavelength-dependent emissivity based on Rayleigh approximation. The results showed that the temperature and emissivity of pine wood combustion were higher than those of rice husk and fir wood volatile flames. Though the emissivity of rice husk was less than that of fir wood, the temperature of rice husk combustion was higher than that of fir wood due to the latter's higher moisture content. The temperatures measured by the spectrometer system agreed well with the thermocouple data. The normalized emissivities of the three different biomass show the same trend, indicating the radiative properties of biomass volatile flames do not change with biomass species and combustion conditions.

Short sugarcane bagasse fibers cementitious composites for building construction

This paper presents an experimental assessment on sugarcane bagasse short fibers reinforced composites, conglomerated by Ordinary Portland Cement and Plaster and containing fine ash from rice husk combustion, for rural autonomous construction. The vegetable bagasse fibers were supplied directly from landfills of small rural sugar industries, smoked on site, washed in laboratory, treated in supersaturated calcium hydroxide at room temperature and dried before mixing. Physical and mechanical properties of components and composites were obtained. Accelerated aging of composites in CO2 rich atmosphere was done in laboratory, assessing the new properties of specimens after this aerial carbonation, in relation with the ordinary ones. Increasing of specific gravity, modulus of rupture, compressive strength, Young's Modulus, decreasing of porosity, water absorption and toughness of the aged composites was obtained. Their ability for building construction as sustainable and eco-efficient construction materials is analyzed.

Utilization of rice husk (Oryza sativa) for amorphous biosilica (SiO2) production as a bacterial attachment

Rice husk as a by-product of the rice milling process has not been utilized optimally. The yield of rice husk waste continues to increase from year to year, considering that Indonesia is the third largest rice producer in the world. Rice husk has a fairly large silica content; therefore, rice husk is widely used as an alternative source of silica. The purpose of this study is to synthesize silica from rice husk and analyse its characteristics. The research method used in silica isolation was carried out by non-thermal and thermal methods. Non-thermal method for removal of inorganic compounds and hydrolysis of organic compounds by acidic solutions (HCl), while the thermal method is carried out by burning rice husks at a temperature of 500 °C to produce rice husk ash. The resulting rice husk ash was processed by the sol-gel method. The resulting silica was determined of its morphology by Scanning Electron Microscopy (SEM), composition, and structure with Fourier Transform Infrared Spectroscopy (FT-IR). The results obtained in this study were white silica with a yield of 84.782%. Biosilica produced is then mixed with certain bacteria, either Serratia sp or Bacilus pumilus. Then, the attachment of bacteria was evaluated by using SEM (Scanning Electron Microscopy).

Biomass Stand-Alone System for Power Supply Option to Remote Isolated Locations

Reliability and continuity of electricity supply generated by the use of fossil fuels cannot be guaranteed absolutely because of the present decline in oil and gas. Because of this, it becomes necessary to consider another form of energy generation such as biomass. In this work, the potential of electricity generation for a small household rural/isolated location using combustion technique was done. Due to the availability of sufficient biomass (agricultural waste) in rural/isolated locations, rice husk combustion technique for biopower generation was investigated in this work. The experiment was conducted at Uburu in Ohaozara Local Government Area of Ebonyi State. A 12V permanent magnet DC motor was used as the alternator while rice husk was used as biomass fuel. The biopower was achieved by heating water to steam which was used to turn the turbine attached to the permanent DC motor and a maximum of 155Whr was generated. From the result, it can be seen that the typical load of a household in a rural/isolated location is 55W and the peak experimental power is 154.96W. This peak experimental power is sufficient to carry the household load in a rural/isolated location. The peak experimental energy value is 1549.6Whr in a 10 minutes interval which is far more than the energy demand of 260Whr in a typical household in rural/isolated location. The result shows that biomass can be used to generate power for lighting point and power outlet for small households in rural/isolated locations.