Tons Of Rice Husk Research Articles

Investigation of silica crystallization kinetics in rice husk ash for sustainable construction materials

Concrete is one of the most widely used materials in the world, and its utilization is rising drastically with the increasing population. Around 5-8% of global carbon emissions are caused by cement production. On the other hand, approximately 160 million tons of rice husk, considered agrowaste, turn into ash annually. Rice husk ash (RHA) is particularly attractive due to its high silica content and great potential to be used as a cementitious material. However, impurities such as alkali metal oxides and uncontrolled combustion reduce the quality of silica and promote its crystallization. Numerous studies have focused on obtaining active silica through acid leaching to remove impurities, but the study on the reaction kinetics of functionalized rice husk ash is very limited. In this research, 0.1M hydrochloric acid (HCl) was used to leach rice husk at temperatures of 50°C, 60°C, and 70°C for 1.5 hours. The rice husk was then burned at 800°C for 2 hours. Subsequently, the ash was examined using various analytical and computational techniques to develop an in-depth understanding of the burning process, aimed at producing functionalized amorphous silica for sustainable construction. It was observed that 99.39% silica with 95.04% amorphous content was formed by treating rice husk with 0.1M HCl at 70°C for 1.5 hours, followed by combustion at 800°C for 2 hours. Furthermore, reaction kinetics parameters were identified using the Coats-Redfern kinetic model for the two different reaction zones of the burning process.

Optimization of the Co-Production between the Rice Husk and the Pulp of the Cashew Apple Produced in the Natural Region of Casamance

Anaerobic digestion or anaerobic digestion is a biological process of degradation of organic matter in an anaerobic environment. It involves the degradation and stabilization of complex organic matter by a consortium of micro-organisms leading to methane-rich biogas that can be used as an alternative energy to fossil fuels. In addition, the use of biogas allows for the preservation of the environment and the sustainable development of rural areas and landlocked regions, as well as the diversification of energy resources, but also contributes to the development of agriculture through the production of organic fertilizer. In 2018, Senegal was ranked as the 15th world exporter of cashew nuts with a production of around 18,000 tons per year according to a study by PADEC (Support Program for the Development of Casamance). Four regions mainly invest in it: Kolda, Ziguinchor, Sédhiou, and Fatick. However, in the natural region of Casamance ( Kolda, Ziguinchor, and Sédhiou), each year, after the cashew nut campaign, more than 342,000 tons of cashew apples, pressed or not, are rejected without any recovery, thus degrading in the environment. In addition, rice is traditionally grown in Casamance and in some Diola circles, it had become one of the criteria of wealth, which explains why it occupied most of the cultivated areas and each year thousands of tons of rice husk are burned for elimination/reduction without any recovery. These immense annual productions of waste, without any recovery, in a context dominated by a deficit in cooking and lighting energy constitutes a form of energy resilience and motivates us to study the co-digestion of the rice husk (with a report of C/N equal to 101.317) on cashew apple pulp (having a C/N ratio of 23.201 ). The study of the co-digestion of rice husk and apple pulp at the laboratory scale with the inoculum reveals, that the co-digestion with pH correction contains 39.40% methane and 51.50% carbon dioxide after 49 days of production and 64.04% methane (CH4) and 25.86% carbon dioxide (CO2) on the 96th day. For co-digestion without adjustment, production stopped on the 49th day with a production of 23.68% methane and 45.65% carbon dioxide.

Analysis of Potential Electric Energy Rice Husk using Gasification Process in West Sumatera

Currently, the use of fuel is increasing, it is feared that fossil fuels will run out in the near future and the national energy policy make the target of the new renewable energy to reach 23% in 2025, especially those most widely used for electricity fuel. Energy from vegetable waste is one of solution to produce new biomass energy an alternative energy to replace fossil fuels. The potential of biomass energy at Indonesian, especially in the West Sumatra area is very large, one of which is solid waste from rice husk agricultural products. In this article, use the rice husk gasification downdraft method to produce synthetic gas to internal combustion engine and coupled with electric generator. The results of rice production at West Sumatera in 2021, which is total of 1.361.769 tons of dry unhulled rice (GKG), will produce 272.353,8 tons of rice husks or about 20% of the total rice production, and mass syngas is 235.335,47 tons, the energy potential electrical 118.924,82 MWh per year. The generator can runs 216 days continuously and cost of fuel is $ 224.64/day vs $302.23/day a diesel engine. So fuel of biomass gasifier 34.5% more efficient compared with the diesel engine.

Analisis Energi Baru Terbarukan Untuk Sistem Kelistrikan Desa

Electricity is a primary need for society. Energy that will never run out of availability is energy from solar radiation. Indonesia is an agricultural country that can utilize alternative energy by utilizing biomass energy, one of which is rice husk and straw waste. Based on data from the BMKG Paloh Station, Sambas Regency has a fairly large intensity of sunlight because it is located just below the equator. The intensity of light in the dry season can reach 6 hours in a period of 8 hours of sunlight, namely from 8.00 - 16.00. The resulting energy conversion is 38.01 mj/m2/day. Meanwhile, for the biomass potential from the BPS data of Sambas Regency in Tebas District, there are 6,730 ha of rice fields, which can produce 403 tons of rice husk and straw waste in one day for 1 year and can produce 5 million Mj/day . The results of the conversion analysis of the optimization of renewable energy for power plants that have an annual peak power of 45kW and daily energy consumption of 330kWh/day obtained the most optimal potential for rice husk and straw waste, which requires an initial capital of $ 67,120 with a total net present minimum cost. Electricity from the system cost is also minimum at US$ 0.005/kWh. And in technical economic analysis, modeling this system requires a payback period of about 11 years without grid bills and 5 years with grid bills. Meanwhile, conversion using PV requires larger capital and longer payback.

The prototype of characterization silica nano particle of rice husk using KOH based on artificial intelligence

One of the abundant sources of biomass is rice husk. Based on data from the Ministry of Agriculture of the Republic of Indonesia, dry grain production in Indonesia reached 83.037150 tons. About 20% of the dry grain is husk. As a result, 16.6 million tons of rice husks were produced in 2018 and their utilization has not been carried out optimally. This research will characterize rice husk silica particles using potassium hydroxide (KOH). The procedure of this research is pyrolysis with a high temperature of 800o with a burning time of 4 hours and 6 hours. The next process is refining rice husk charcoal using High Energy Milling (HEM). The SEM and EDX test results show that the pyrolysis 800°C, 4 hours results in a higher% silica, namely 18.64% with 40.52% carbon. While the results of 800°C, 6 hours pyrolysis produced 35% silica with 28.04% carbon. The data obtained from this study became data in Artificial Intelligence (AI) software to determine the higher silica content of rice husks from several variations of pyrolysis. The results of this measurement, it becomes data for AI software to determine the higher % silica. From the experimental results of the two variations, 800° 6 hours pyrolysis resulted in higher silica.

Co-Pyrolysis of Rice Husk and Chicken Manure

Abstract The increase in the production scale of chicken causes an increment in the produced manure. Chicken manure is considered an excellent soil amendment due to the high nitrogen and phosphorous content. However, the high production of manure exceeds the soil requirements. Rice husk is a by-product of rice production. Approximately one hundred forty million tons of rice husk is produced per year worldwide. There are several ways to manage rice husk such as animal bedding, direct combustion, or as a soil fertilizer. The husk's ashes are suitable for construction or as reinforcing material due to the high silica content. However, rice husk has a low volatile matter and high silica content, which makes processes like direct combustion inefficient. Thermochemical processes (such as pyrolysis and gasification) are effective ways to manage waste. The present study investigates the co-pyrolysis of chicken manure and rice husk. The experiments were conducted in a non-isothermal gravimetrical analyzer using nitrogen at a flowrate of 100 ml/min at three different heating rates (5, 10, and 15 °C/min). The degradation of individual biomass and biomass blends is investigated. The kinetic parameters are calculated using the Friedman method. Results show a positive synergetic effect for mixing ratios greater than 20% rice husk. The mixing ratio of 40% of rice husk manifested the best performance among all blends. This mixture showed the minimum energy of activation (90.2 kJ/mol). Also, the 40% rice husk mixing ratio showed maximum conversion when compared with chicken manure's conversion.

Life cycle assessment of rice husk torrefaction and prospects for decentralized facilities at rice mills

Utilization of rice husk, an abundant global residual biomass, represent a large opportunity for increasing the share of bioenergy in the power sector. The present work assesses the life cycle emissions of rice husk torrefaction in different reaction conditions and the techno-economic prospects for decentralized torrefaction facilities at rice mills. First, a cradle-to-gate life cycle assessment (LCA) is performed for processing rice husk into torrefied pellets for energy generation. Four system configurations of different temperature and torrefaction medium are considered for torrefied rice husk (TRH) pellet production. Medium torrefaction in inert medium shows the highest GHG emissions of about 0.043 kg CO2 eq/MJ of TRH pellet whereas severe torrefaction in oxidative medium shows the lowest GHG emissions of 0.021 kg CO2 eq/MJ of TRH pellet. The environmental impacts of torrefaction in partially oxidative medium and at higher temperatures are lower, only if a significant portion of the torgas and condensate is efficiently utilized. Second, a techno-enviro-economic evaluation is performed for multiple scenarios of utilizing raw or torrefied rice husk (partially oxidative conditions) for power generation. A case study of the rice mills in the Sacramento valley of California is considered, with an annual supply of about 0.2 million tons of rice husk, to operate a 26.5 MW biopower plant. A centralized facility at the power plant resulted in highest GHG emissions, and a rented mobile facility resulted in highest annual costs. The most desired scenario of having localized facilities at the rice mills proved most cost-effective, with excess TRH breakeven price of 61 USD/ton for medium torrefaction and 471 USD/ton for severe torrefaction. Instead of excess TRH, if the entire TRH is available for sale, the same scenario estimated the average breakeven price of 14.9 USD/ton and 21.1 USD/ton respectively. Sensitivity analysis for a single mill explains the role of factors such as availability of rice husk (milling capacity), transportation distance, and solid mass yield on the breakeven price, costs, and the GHG emissions.

Development of an Efficient Method in the Extraction of Silica from Rice Husk Ash

Rice is one of the major crops grown through the world. Once the paddy is separated from the rice grain, the husk is removed from the grain. This constitute one third of the total mass of grains, commonly known as “Rice Husk”. Rice husk is an agricultural waste abundantly available in producing countries. India alone produces 24 million tons of rice husks every year. Worldwide annual husk output is 80 million tons. Rice husk is considered as a form of waste from rice milling processes and are often left rot in field or burnt in open. But rice husk contains silica in range of 80-90% weight. The silica in rice husk exists in the hydrated amorphous from like silica gel which is easily extractable at a lower temperature range. Energy is also produced in the process which could be recovered in the form of heat or electricity

Assessment of Crop Residues Energy Potential and Efficient Usage in the South-western Zone of Afghanistan

In the south-western zone of Afghanistan (Kandahar, Helmand, Urozgan and Zabul) about 807,890 tons of wheat, 945 tons of rice, 46,164 tons of barley and 105,276 tons of maize were produced in 2016-17. Based on the residues to product ratio (RPR) of the crops (1.8 for wheat straw, 1.5 rice stalks, 0.2 for rice husk, 1.3 for barely straw and 2 for maize stalks) about 1,454,202 tons of wheat straw, 1,418 tons of rice stalks, 189 tons of rice husk, 60,013 tons of barely straw and 210,552 tons of maize stalks were generated in the south-western zone of the country. By considering the lower heating values (LHV) of the crop residues (13.76 MJ/kg for wheat straw, 12.81 MJ/kg for rice stalks, 16.33 MJ/kg for rice husk, 13.97 MJ/kg for barely straw and 13.22 MJ/kg for maize stalks), it was resulted that 20,010 TJ energy can be generated from wheat straw, 18 TJ from rice stalks, 3 TJ from rice husk, 838 TJ from barely straw and 2,783 TJ from maize stalks. Cumulatively, around 23,653 TJ of energy can be generated from the selected crop residues in the south-western zone of Afghanistan in 2016-17. These crop residues are mainly used for cooking by using the very inefficient three stone cook stoves (? = 12.6%) and two support cook stoves (? = 13%). To use these crop residues more efficiently, it is advised to replace the mentioned inefficient cook stove with improved Chulha and Anagi II cook stoves, which have an efficiency of 21% and 22% and can save off to 43% and 40% fuel wood, respectively compared to the traditionally used cook stoves.

Assessment of Crop Residues Energy Potential and Efficient Usage in the South-western Zone of Afghanistan

In the south-western zone of Afghanistan (Kandahar, Helmand, Urozgan and Zabul) about 807,890 tons of wheat, 945 tons of rice, 46,164 tons of barley and 105,276 tons of maize were produced in 2016-17. Based on the residues to product ratio (RPR) of the crops (1.8 for wheat straw, 1.5 rice stalks, 0.2 for rice husk, 1.3 for barely straw and 2 for maize stalks) about 1,454,202 tons of wheat straw, 1,418 tons of rice stalks, 189 tons of rice husk, 60,013 tons of barely straw and 210,552 tons of maize stalks were generated in the south-western zone of the country. By considering the lower heating values (LHV) of the crop residues (13.76 MJ/kg for wheat straw, 12.81 MJ/kg for rice stalks, 16.33 MJ/kg for rice husk, 13.97 MJ/kg for barely straw and 13.22 MJ/kg for maize stalks), it was resulted that 20,010 TJ energy can be generated from wheat straw, 18 TJ from rice stalks, 3 TJ from rice husk, 838 TJ from barely straw and 2,783 TJ from maize stalks. Cumulatively, around 23,653 TJ of energy can be generated from the selected crop residues in the south-western zone of Afghanistan in 2016-17. These crop residues are mainly used for cooking by using the very inefficient three stone cook stoves (η = 12.6%) and two support cook stoves (η = 13%). To use these crop residues more efficiently, it is advised to replace the mentioned inefficient cook stove with improved Chulha and Anagi II cook stoves, which have an efficiency of 21% and 22% and can save off to 43% and 40% fuel wood, respectively compared to the traditionally used cook stoves.

Life Cycle Assessment of rice husk as an energy source. A Peruvian case study

Energy consumption linked to non-renewable resources such as fossil fuels contributes to greenhouse gas emissions and increases resource depletion. In this context, the use of agricultural solid residues such as rice husk, coffee husk, wheat straw, sugar cane bagasse, among others, has been widely studied as an alternative energy source in order to decrease the use of fossil fuels. In Peru, up to 693,308 metric tons of rice husk is generated annually and at present, 85% is burned in the open air or disposed in rivers, harming human health and contaminating our environment. On the other hand, official Peruvian energy policy is to incorporate the use of renewable energy sources, such as agricultural residues. Consequently, the aim of the study is to perform a technical and environmental assessment of the production of energy from rice husk as an alternative energy source to coal in Peru. Rice husk from Peru was characterized to identify its physical properties and chemical composition. In order to perform the environmental assessment, a Life Cycle Assessment (LCA) was employed. LCA is a standardized methodology to identify and quantify the environmental impacts from initial obtention of materials, through production, distribution and use to final disposal (ISO 14040, 2006 and ISO 14044, 2006). Four scenarios were evaluated, varying in paddy rice yield and dryer efficiency. The results show that the environmental impacts to obtain 1 MJ from rice husk, including elements in the global warming, acidification and eutrophication categories, are less than that from 1 MJ obtained from coal, 97%, 88% and 80% less, respectively. However, the opposite was found in water depletion, with the use of coal to generate heat having a 98% better impact over rice husk.

Artificial neural network based modelling approach for strength prediction of concrete incorporating agricultural and construction wastes

Construction debris and agricultural wastes are among the major environmental concerns in the world. Construction debris consumes about 28% of the nation’s landfill facilities. Over 254.5 million tons of rice husk is available for disposal every year. A large amount of these materials can be recycled and reused as aggregate and cement substitutes for general construction and pavements among other works. In this study, effort was made to develop artificial neural network (ANN) model for predicting the 28-day strength of concrete incorporating rice husk ash (RHA) and reclaimed asphalt pavement (RAP) as partial replacements of Portland cement and virgin aggregates respectively. The ANN model predicted the compressive and tensile splitting strengths with prediction error values of 0.648 and 0.072 MPa respectively. The model overpredicted the compressive strength (fc) on average by 0.123 MPa, whereas it underpredicted the tensile strength (fts) by 0.019 MPa. The predicted compressive and tensile strengths deviated on average by 2.088 and 2.905% respectively from experimental results. The results indicate that the ANN is an efficient model to be used as a tool for predicting the compressive and tensile strengths of concrete incorporating RHA and RAP.

Synthesis and Characterization of Nano Silica from Rice Husk Ash

India produces annually 120 million tonnes of paddy. From the paddy growth, around 24 million tons of rice husk and 4.4 million tons of Rice Hush Ash are produced every year. Abundant silicon is observed to be contained within the agricultural biomass of rice husk. In the present article, nano-silica preparation from rice husk ash is carried using dissolution-precipitation technique which is a function of acid treatment, sodium silicate concentration, pH, aging temperature, aging time to establish optimum conditions for synthesis. The experimental process is carried by purging of carbon dioxide in alkaline solutions. Initially, nano amorphous silica was obtained after calcinations of rice husk ash at 600⁰C, 700⁰C, 800⁰C for 2 hrs. Calcinations results in removal of volatile components. Calcined RHA was mixed with alkali solution to produce sodium silicate solution and then precipitated silica was obtained by the neutralization of sodium silicate solution with carbon dioxide purging. Extracted precipitated silica particles were characterized by XRD, Fourier transform infrared (FTIR) and SEM for phase determinations, bonding formations and morphological features.

Critical Process in Paddy Residue-Based Power Generation in Malaysia: Economic and Environmental Perspective

Malaysia is one of the leading producers of paddy. It has reached 0.48 million metric tonnes of rice husk and 3.1 million metric tonnes of rice straw in a year due to the emerging technological development in agroindustry.The consumption of paddy residue (both rice husk and rice straw) in electricity generation creates a vast potential to explore. However, the generation of electricity from paddy residue faces various environmental, technological, and social challenges.This paper identifies the most critical processes in paddy residue-based power generation towards the environmental and economic impacts.The transportation process is the most critical part, where personnel cost is the most sensitive cost to this process.The rice husk electricity generation cost is RM0.6075/kWh and rice straw is RM0.2725/kWh.The overall process, beginning from the production of paddy residue until electricity generation, will be examined to find the critical process in paddy residue-based power generation. This paper can encourage the utilization of renewable energy, parallel to the government policy to move with green energy, and can serve as a guideline for policy makers in the implementation of more renewable energy in Malaysia.

Productive potential and quality of rice husk and straw for biorefineries

The use of lignocellulosic biomass to obtain high value-added products and biofuels has been highlighted in the last years, introducing the biorefinery concept. Among the types of lignocellulosics that can be used in biorefineries, there are rice husk and rice straw, byproducts of rice production usually treated as waste. Every year, 650–975 million tons of rice straw and 800 million tons of rice husk are generated during cultivation and processing of rice. This paper accomplishes a review of potential utilization of rice husk and rice straw in biorefineries approaching its chemical, biochemical, and thermochemical conversions in biofuels, biomaterials, biochemicals, bioenergy, and other high value-added products. The composition of lignocellulosic biomass, as well as the intra and intermolecular interactions among cellulose, hemicelluloses, and lignin in the biomass structure responsible for its recalcitrant characteristics are discussed. The need of performing a pretreatment prior to bioconversion due to biomass recalcitrance and different possible bioconversion processes are approached.

Optimization of rice husk pretreatment for energy production

One of the most widely cultivated crops in the world is rice, leading to millions of tons of rice husks (also known as rice hulls or chaffs). The large amount of this lignocellulosic biowaste has resulted in an extensive search for its utilization. One such usage of this waste is for the production of electricity, such as in combined heat and power or gasification units. However, one of the disadvantages of using rice husks is their high silica content which produces large amounts of undesirable ash upon combustion leading to operation problems such as slagging and clogging. Here, alkali pretreatment for the extraction of silica in the form of sodium silicate has been studied using response surface methodology (RSM) and Analysis of Variance (ANOVA). Three independent variables namely reaction temperature, duration, and alkali concentration were considered using a Box–Behnken design (BBD). The operating conditions were optimized under different scenarios. The first optimization focused on the two goals of high ash removal and high solid yield while the next optimization rounds added the criteria of low NaOH usage and robust design (using propagation of error (POE)). The final treated rice husks can therefore be more suitably used as feed for thermal and/or electric units. The developed empirical predictive models were successfully validated through additional experimentation.

Present and prospective energy use potentials of selected agricultural wastes in Nigeria

The present study reviews the potential energy applications of wastes derived from rice, cocoa, and oil palm to augment energy needs while helping to abate environmental pollution. It also highlights the potentials of animal dungs for energy production in Nigeria. The country currently produces about 2.7 × 106 tons of rice annually, containing 0.540 × 106 tons of rice husk and a similar quantity of straw, which can be used for energy production. About 6.22 × 109 MJ of energy can be derived from the 266 000 tons (which could rise to 490 000 tons by 2015) of cocoa pods, which are currently produced and discarded annually. This could be utilized to generate process heat, either through thermal cycle or biochemical conversion. With respect to oil palm wastes, Nigeria generated about 0.344 × 106 tonnes of empty fruit bunches, 0.246 × 106 tonnes of palm shells, 0.633 × 106 tonnes of palm oil mill effluent, and 0.382 × 106 tonnes of mesocarp fibre in 2012, which are capable of producing substantial amounts of energy. Nigeria's livestock population is increasing at an annual rate of 3.2%, with current dung production of 407 × 103 tons/day (cow), 28 × 103 tons/day (pigs), 6.6 × 103 tons/day (chicken broilers), etc., which is estimated to produce 6.8 × 106 m3 of biogas daily. Electricity derivable from this quantity of biogas can provide lighting for 2.4 × 106 rural households in Nigeria.

GASIFIKASI SEKAM PADI (BIONER-1)

Indonesia has potential abudant biomass wastes. Annual paddy production in Indonesia is approximately 50 million tons, from which 14 tons of rice husks is produced, assuming that each ton paddy could produce 0.28 tons of rice husks. At its calorific value of 12.5 MJ/kg, the annual potential energy provided by these husks is around 175 GJ. A gasification system using rice husk would normally require 1.5 to 2 kg of rice husks to generate 1 kWh of electricity. Therefore, each ton of rice milled could produce wastes that equals to electricity generation of 150 kWh. Rice husk is about 14 to 28.5% of a rice grain, but mostly has an average value of 25%. A gasification Bioner-1 system is operated 14 hours per day in 366 days per year. This system will drive a rice milling unit for 8 hours per day and produce electricity for villagers for another 6 hours in the evening. At a fuel consumption of 25 kg per hour, the system will require 130 tons of husks that will be provided from rice fields of around 175 ha. Gas (syngas) produced from the gasification will be used for a dual fuel diesel engine system, supplementing diesel fuel. The diesel fuel substituted by the gas could reach about 75-80%. At a consumption rate of 25 kg/hour rice husks in the system, the husks consumption per kWh electricity is 1.5 kg (1.5 kg/kWh) and the efficiency of rice husks conversion is 15%. A small portion of tar could still escape from a gas cleaning system. The tar could be observed during overhoul of the diesel engine. The tar entering into the diesel engine is overcome through switching on the diesel engine for about 10 minutes and flushing using diesel oil right before it is shutted down. Through this method, the tar entering the diesel engine is completely burned. Kata kunci gasification, biomas, rice husk, diesel engine

Combustion behaviour of rice husk in a bubbling fluidised bed

The combustion of agro-industrial wastes in power plant seems to be an attractive possibility for the future. In Spain, the food industry generates around 618,000 tonnes of rice husk annually. The rice production is geographically focused in three regions: Valencia, Andalucia and Delta del Ebro. The rice husk is a suitable fuel for the fluidised bed combustors. An experimental combustion work using the rice husk as fuel was performed in a 30 kW th atmospheric bubbling fluidised bed pilot plant of CIEMAT. The influence of different variables such as temperature, fluidisation velocity on the combustion efficiency and CO emissions was investigated. Combustion efficiency in all test runs was higher than 97%. The characteristics of ash removed from the bed, cyclones and baghouse were studied. In the bed ashes, the potassium content increases along the operation hours.

Overview of combustion and gasification of rice husk in fluidized bed reactors

Rice is cultivated in more than 75 countries in the world. The rice husk is the outer cover of the rice and on average it accounts for 20% of the paddy produced, on weight basis. The worldwide annual husk output is about 80 million tonnes with an annual energy potential of 1.2×10 [9]GJ corresponding to a heating value of 15 MJ/kg. India alone generates about 22 million tonnes of rice husk per year. If an efficient method is available, the husk can be converted to a useful form of energy to meet the thermal and mechanical energy requirements of the rice mills themselves. This paper provides an overview of previous works on combustion and gasification of rice husk in atmospheric bubbling fluidized bed reactors and summarizes the state of the art knowledge. As the high ash content, low bulk density, poor flow characteristics and low ash melting point makes the other types of reactors like grate furnaces and downdraft gasifiers either inefficient or unsuitable for rice husk conversion to energy, the fluidized bed reactor seems to be the promising choice. The overview shows that the reported results are from only small bench or lab scale units. Although a combustion efficiency of about 80% can normally be attained; the reported values in the literature, which are more than 95%, seem to be in higher order. Combustion intensity of about 530 kg/h/m [2]is reported. It is also technically feasible to gasify rice husk in a fluidized bed reactor to yield combustible producer gas, even with sufficient heating value for application in internal combustion engines. A combustible gas with heating value of 4–6 MJ/Nm [3]at a rate of 2.8–4.6 MW th/m [2]seems to be possible. Only very little information is available on the pollutant emissions in combustion and tar emissions from gasification. The major conclusion is that the results reported in the literature are limited and vary widely, emphasizing the need for further research to establish suitable and optimum operating conditions for commercial implementations.