Rice Husk Gasification Research Articles

Solid residues after gasification of agricultural residues as scalable and economical CO2 adsorption materials

Economical CO2 adsorbents are gaining significant attention as viable solutions to combat climate change. This research assessed the CO2 adsorption potential of solid residues following the gasification of bagasse (SR-Bagasse), bamboo (SR-Bamboo), and rice husk (SR-Rice husk) in various systems in Vietnam and Cambodia. Among these residues, SR-Bagasse showed the highest CO2 adsorption capacity, followed by SR-Bamboo, while SR-Rice husk exhibited moderate performance. The CO2 adsorption capacity at 25 °C with 100 % CO2 flow varied from 6 % to 9.5 % of the adsorbent's weight. Under flue gas conditions (15 % CO2 and 85 % N2), the adsorption capacity ranged from 2 % to 5 %. Additionally, these chars demonstrated significant recyclability with 90 % of initial adsorption capacity retained after 30 cycles, making them comparable to several advanced CO2 adsorbents studied previously. The highest performance of SR-Bagasse could be attributed to its substantial microporous and ultra-microporous volumes, with micropores serving as both CO2 adsorption sites and conduits to ultra-micropores. This study's findings emphasize the potential for integrating energy production with the development of economical and scalable CO2 adsorbents for industrial use.

Experimental and Adsorption Kinetics Study of Hg0 Removal from Flue Gas by Silver-Loaded Rice Husk Gasification Char

Experimental and Adsorption Kinetics Study of Hg0 Removal from Flue Gas by Silver-Loaded Rice Husk Gasification Char

Experimental Biomass Gasification in Updraft Gasifier with Gas Outlet at Reduction Zone and Air Supply using Suction Blower

Rice husk gasification is increasingly attractive, particularly with updraft gasifier type, because of its simple construction and ease of operation. However, updraft gasifier has a disadvantage of generating substantial amounts of tar. Tar will decompose into combustible gas when exposed to high temperatures. The reduction zone has a high temperature for tar decomposition to occur. Therefore, in this research, updraft gasifier was modified by positioning gas outlet at the reduction zone and inducing gasification air supply using a blower. Modifications are made by moving the gas outlet from the top to the middle or reduction area. The initial start-up of the system uses a blown air supply system, then after the syngas are produced by the operation, it is replaced with a sucked air supply. Two blowers are used, namely an exhalation or blowing blower for initial start and a suction blower for continuous operation. The fuel used was low bulk density, specifically rice husks. The aim was to characterize the modified gasifier, focusing on parameters such as operating time, duration of gas combustion, air-to-rice husks ratio, and flame color. Typically, the experiments were conducted under constant of air velocity and fuel quantity. The results showed that the average operating time, duration of flammable gas, and air-to-rice husks ratio were 74.25 minutes, 52.28 minutes, and 7.6 kg air/kg husk, respectively, and the flame produced was a bluish-yellow color that indicates a reduction tar.

Component-based equilibrium modeling of biomass fixed-bed gasifier

In this paper, the process of gasification of rice husk directly with air in a fixed-bed gasifier was modeled using Aspen Plus. Unlike traditional models based on the elemental balance method, this study modeled the decomposition of rice husk into cellulose, lignin, and hemicellulose based on experimental data from the pyrolysis equipment, and the product yields were fitted to obtain the distribution of product yields in the pyrolysis stage of rice husk. In the redox stage, the thermodynamic equilibrium calculation model and the kinetic calculation model were used for the simulation, respectively, and compared and analyzed with the actual plant operation data. In the simulation of the thermodynamic equilibrium calculation model, the error of gas yield was about 5%. While in the kinetic calculation model, the errors of gas production rates of N2, H2 and CH4 were within 5%, the errors of CO and CO2 were larger, which were 13.73% and 17.09%, respectively. The error of the yield of Bio-char, an additional product of gasification, is about 2% in both models, which is close to the actual working conditions. Based on the model, the effects of gasification temperature, air equivalent ratio (ER) and air preheating temperature on the gasification reaction were discussed in this paper. The results concluded that the gasification temperature should be maintained at about 800 °C, the air equivalent ratio at about 0.3, and the air preheating temperature should be increased appropriately when performing rice husk gasification.

A comparative ammonia recovery study of solid wastes discharged from rice husk gasifi cation and combustion plants

A comparative ammonia recovery study of solid wastes discharged from rice husk gasifi cation and combustion plants

Life cycle analysis and economic evaluation of cement and concrete mixes with rice husk ash: application to the Colombian context

Rice husk residues are generated within the rice industry. In this research, the environmental impact of the use of rice husk ash is evaluated as a replacement for cement in the production of concrete in the city of Ibagué (Colombia). The environmental criteria of cement and concrete production alternatives were evaluated through life cycle analysis methodology, using SimaPro 9.3.3 software and the Recipe 2016 Midpoint (H) evaluation method. The economic cost of each of these production alternatives was included. To carry out the study, surveys and interviews had to be undertaken with rice-producing plants, aggregates, cement and concrete plants in Tolima. It was corroborated that rice husk ash (RHA) generated during the rice husk (RH) gasification process for electricity and heat production was beneficial from an environmental and economic perspective when it was used in cement and concrete in the city of Ibague (Colombia).

Effect of syngas recirculation in the pyrolysis zone on the rice husk gasification process using the downdraft reactor

As one of the world's largest rice producers, Indonesia has an abundance of rice husk as a byproduct of rice milling. Rice husks were utilized to examine downdraft gasification with syngas recirculation system. This study attempts to produce better syngas than conventional downdraft gasifier. With an equivalency ratio of 0.20, syngas was recirculated into the reactor in the pyrolysis zone with valve openings at 25%, 50%, and 75%. This study determined the syngas recycling ratio that maximizes H2 and CO gas and decreases tar. Increasing the syngas recirculation valve (25%, 50%, and 75%) accelerates flame propagation and pyrolysis zone temperature. Syngas study showed no recirculation condition produces the maximum CO2 and CH4. Different recirculation valve openings little affect CO and CH4 gas composition. The H2 gas composition demonstrates that valve openings significantly change H2 gas generation and that the peak was at 50% syngas recirculation. Tar content decreased to 30% and 35% at 50% and 75% valve openings. Based on H2/CO comparison and tar concentration, 50% opening syngas recirculation became the optimum case.

A Systematic Review of Rice Husk Gasifiers: Technology, Performance, and Sustainability

Pursuing sustainable energy solutions has increased interest in utilizing agricultural waste for energy generation. Among these waste materials, rice husk stands out due to its abundance and potential as a renewable energy source. Gasification, a thermochemical process converting biomass into valuable synthesis gas (syngas), offers a promising pathway for harnessing the energy content of rice husk. This systematic review presents a comprehensive analysis of rice husk gasification, focusing on technology, performance, and sustainability aspects. Drawing from a wide range of literature sources, including research studies, technical reports, and advancements in gasification techniques, the review aims to provide a holistic understanding of the field. The review elucidates the different gasifier technologies used for rice husk gasification, discusses performance metrics evaluating gasification efficiency, gas composition, and energy yield, and examines the sustainability implications of the technology. It also analyzes the influence of rice husk characteristics on gasification outcomes and identifies trends, innovations, and persistent challenges within the domain. This review improves rice husk gasification research by categorizing and synthesizing. Researchers, politicians, and industry stakeholders looking to understand the technology's potential and limitations might benefit from its findings. This evaluation helps guide decision-making and promote rice husk gasification innovations as the globe transitions to sustainable energy.

Energetic, exergetic, economic and environmental performance of a rice husk gasification based carbon negative combined power and cooling plant

This article presents the proposed configuration of a biomass gasification based carbon-negative combined power and cooling system. Parametric alteration of the response variables with respect to the individual input variables as well as the interaction of the input variables on response have been studied. Detailed analysis of variance has been carried out for the response variables (exergy utilization factor and modified unit electricity cost) and optimization of the whole plant has been performed employing response surface methodology. At the optimum operating condition, for both power and cooling, the plant utilizes 32.39 % of input exergy at an effective electricity cost of 0.1186 $/kWh (including the cost of CO2 capture), having a desirability of about 1. CO2 capture and the environmental benefit due to CO2 cutting at optimum operating condition found to be 1.517 M ton/yr and 0.2275 B$/yr respectively.

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.

Producer Gas Composition Prediction using Artificial Neural Network Algorithm

Nowadays, methods to increase efficiency in producer gas have become major issues in biomass gasification research. Producer gas is a renewable energy source that does not take as much time to obtain as fossil fuels. It is typically a mixture of combustible gases like carbon monoxide, hydrogen and methane, and non-combustible gases like carbon dioxide and nitrogen. A high percentage volume of combustible composition in the producer gas output will have a high calorific value or heat of combustion. These combustible gases are determined by the design of the gasifier. In today's era of Industrial Revolution 4.0 and Society 5.0, the use of simulation is highly prioritised in all aspects of engineering, especially in gasification applications. Simulation is a useful tool for learning about the governing principles and optimal operating points of the gasification process. Artificial intelligence (AI), is a major focus of Industry Revolution 4.0. In this project, the producer gas composition prediction is studied by computer simulation. The goals are to predict the output producer gas using an algorithm and to compare the trained prediction result with actual experiment data for rice husk gasification. This simulation was created with MATLAB software's artificial neural network (ANN). Three parameters (the height of the gasifier, the diameter of the gasifier, and the weight of the rice husk) are set as input data, and six types of the composition of producer gas (carbon dioxide, carbon monoxide, methane, oxygen, hydrogen, and nitrogen) are set as output data. The algorithm is trained, tested, and verified with the experiment data. It is then used to predict the output gas composition from the parameters of a gasification experiment that has been used before in UiTM’s laboratory. The simulation results of producer gas composition between prediction and actual values revealed a relative error of 1.159 %, 0.370 %, and 0.330 %. These results were less than 9% and were found to give a very good fit to the neural network algorithm.

Enhanced hydrogen production via staged catalytic gasification of rice husk using Ca(OH)2 adsorbent and Ce–Ni/γAl2O3 catalyst in a fluidized bed

Hydrogen production from rice husk was carried out via a two-stage system combining CLG (calcium looping gasification) using Ca(OH)2 adsorbent in a bubbling fluidized bed and catalytic reforming with Ce–Ni/γAl2O3 catalyst in a connected fixed bed. The results show that the maximum H2 concentration (69.16 vol%) and H2 yield (11.86 mmol g−1rice husk) are achieved at Ca/C (Ca(OH)2 to carbon molar ratio) = 1.5, H2O/C (H2O to carbon molar ratio) = 1.5, Tg (gasification temperature) = 500 °C, Tc (catalytic temperature) = 800 °C. The supplementation of fresh Ca(OH)2 at Ca/C of 0.5 during calcination helps to activate the regenerated CaO by hydration, maintaining its carbonation activity and CO2 adsorption. Ce–Ni/γAl2O3 catalyst promotes water gas shift (WGS), steam methane reforming (SMR), and C2–C3 hydrocarbons reforming, also exhibits excellent activity stability to maintain H2 concentration and H2 yield above 67.21 vol% and 11.67 mmol g−1rice husk, respectively, during 5 lifetime tests.

Mobile Rice Husk Gasifier Performance and Techno-Economic Analysis as Micro Scale Power Generation: Modeling and Experiment

Indonesia annually produces significant amounts of biomass waste in the agriculture sector. Rice husk, one of the highest produced agricultural waste materials, has sufficient caloric value to produce syngas in a gasification system to generate sustainable energy. However, the production of tar from rice husk gasification is significantly high, damaging the equipment and internal combustion engine. This study carried out performance analysis on a small-scale rice husk gasifier. A simulation provided a syngas composition overview and showed a maximum LHV value of 6.47 MJ/Nm3 at ER 0.25, and a maximum CGE value of 83% at a temperature of 900 ℃. Furthermore, the economic aspect of integrating renewable technology was also considered. The gasifier had an LCOE value ranging from 0.014 to 0.089 USD/kW, depending on the use of the gasifier. The feasibility of using a mobile rice husk gasifier was also inspected, based on net present value, benefit-to-cost ratio, and payback period.

Experiment and Simulation of Rice husk Gasification Process with a Downdraft Gasifier

Experiment and Simulation of Rice husk Gasification Process with a Downdraft Gasifier

Experimental microwave-assisted air gasification of biomass in fluidized bed reactor

Microwave-assisted heating is an effective heating method for thermochemical conversion of biomass. In this study, experimental syngas production from microwave-assisted air gasification of biomass in a fluidized bed reactor at different gasification temperatures, equivalence ratios and silicon carbide loads, was studied and reported. The results showed that the highest syngas yield (78.2 wt%), higher heating value (6.3 MJ/Nm3) and cold gas efficiency (81.8 %) were obtained at gasification temperature of 900 °C, equivalence ratio of 0.35 and silicon carbide load of 30 g, and the gasification temperature had significant influence on the syngas production. Microwave-assisted heating showed positive effect on tar reduction, i.e., the tar content at 900 °C (2.1 wt%) in this study was even lower than the tar content (3.2 wt%) from catalytic electrical air gasification of rice husk at 950 °C. Generally, the introduction of microwave-assisted heating showed positive effect on biomass gasification.

Numerical modeling of rice husk gasification in fluidized bed gasifier for sustainable biofuel production

Currently, there is a growing interest in various alternative energy sources due to the global energy scenario and rising crude oil prices. Renewable sources of energy like biomass can be exploited to produce energy-rich syngas. The biomass gasification process converts energy-rich solid fuel into syngas by partial combustion. In the present study, rice husk gasification using steam and, a mixture of steam and CO2 at temperatures ranging from 650°C to 750 °C and steam to biomass ratio of 0.5–2 is studied. Steam gasification enhances hydrogen production, and mixing with CO2 helps optimizing the H2/CO ratio. The study uses the Euler-Euler method in combination with kinetic theory granular of flow which is modeled using the computational fluid dynamics approach implementing user-defined functions for heterogeneous char reactions. The increased particle diameter harms the gasification performance due to the lower heating value of the syngas. As the steam to biomass ratio is increased, there is a positive effect on syngas quality, while temperature has a negative effect. The addition of CO2 increases the CO conversion in the syngas. The heterogeneous reaction rate vanishes close to zero after a height of 0.4 m, where all solid carbon is consumed.

Co-pyrolysis of municipal solid waste and rice husk gasification tar to prepare biochar: An optimization study using response surface methodology

Organic household waste and tar constitute the typical municipal solid waste (MSW) and biomass gasification liquid waste, respectively. In this study, biochar was prepared by co-pyrolysis of simulated MSW samples and rice husk gasification tar as experimental materials. The effects of three factors of co-pyrolysis, namely, pyrolysis temperature, residence time, and tar percentage on the biochar yield and quality were systematically evaluated by response surface methodology. The results reveal that the experimental mass yield, fixed carbon content, and higher heating value (HHV) of biochar increased by 2.06 %, 3.3 %, and 1.08 MJ kg−1, respectively, compared to the theoretical values under the optimized conditions of co-pyrolysis (600 °C, 17.5 min, and an MSW/tar mass ratio of 1:1). Thus, the synergistic effects occurred during the co-pyrolysis of MSW and tar. The three factors differently affected the properties of biochar. In general, the influence degree among three factors on biochar yield is in the following order: tar percentage > pyrolysis temperature > residence time. Among the three factors, the tar percentage showed the greatest influence on the HHV of biochar, while the pyrolysis temperature played a major role in deciding the fixed carbon content of biochar. The fitting equations were established for biochar and the three factors of co-pyrolysis, which provide data basis for effective use of MSW and tar. Finally, the experimental optimization conditions for biochar to reach the maximum yield, maximum carbon content, and maximum HHV were recommended.

Process modeling and evaluation of optimal operating conditions for production of hydrogen-rich syngas from air gasification of rice husks using aspen plus and response surface methodology

Biomass gasification is recognized as a viable avenue to accelerate the sustainable production of hydrogen. In this work, a numerical simulation model of air gasification of rice husks is developed using the Aspen Plus to investigate the feasibility of producing hydrogen-rich syngas. The model is experimentally validated with rice husk gasification results and other published studies. The influence of temperature and equivalence ratio on the syngas composition, H2 yield, LHVSyngas, H2/CO ratio, CGE, and PCG was studied. Furthermore, the synchronized effects of temperature and ER are studied using RSM to determine the operational point of maximizing H2 yield and PCG. The RSM analysis results show optimum performance at temperatures between 820 °C and 1090 °C and ER in the range of 0.06–0.10. The findings show that optimal operating conditions of the gasification system can be achieved at a more refined precision through simulations coupled with advanced optimization techniques.

Biomass and low-density polyethylene waste composites gasification: Orthogonal array design of Taguchi technique for analysis and optimization

This modeling study explores and optimizes the performance of the gasification of a rice husk and low-density polyethylene waste composite utilizing an orthogonal array design of a Taguchi technique. This modeling study uses a signal to noise ratio analysis to optimize the gasification of rice husk and low-density polyethylene waste composite and utilizes an analysis of variance approach to identify the most important factors contributing to the process. It is shown that the composition ratio of rice husk and polyethylene waste contributes significantly to the gasification performance. Increasing composition ratio of rice husk and polyethylene waste improves hydrogen concentration, decreases carbon dioxide concentration and enhances carbon monoxide concentration. Energy efficiency is enhanced and normalized carbon dioxide emission is improved by increasing composition ratio of rice husk and polyethylene waste. The gasification of rice husk and low-density polyethylene waste composite is efficient (total energy efficiency of 77.6%) and clean (normalized carbon dioxide emission of 2.1 g/mol, based on the composite entering the system) at its multi-objective optimum conditions. The research results support the development of a system for gasification of biomass and plastic waste composites utilizing orthogonal array design of a Taguchi approach.

Enrichment of hydrogen in product gas from a pilot-scale rice husk updraft gasification system

An updraft gasifier was employed to treat 3 kg of dried rice husk per batch with different types of gasifying agents such as air, steam/air, and air with dolomite catalyst addition at various operating conditions. The H2 content, low heating value, and H2/CO ratio in syngas were compared to determine the most effective solution to enhance the H2 production from rice husk gasification. The presence of dolomite in air gasification produced the highest H2 content in the product gas, up to 15.4 mol%, followed by 7.08 and 3.6 mol% when steam/air and air standalone were used as gasifying agents, respectively. The higher low heating value of syngas 5.1 MJ/Nm3 was observed in catalytic air gasification compared to 3.6 MJ/Nm3 when steam was added. The optimal operation condition was reported at an airflow rate of 3 m3/h and a catalyst mixing ratio of 15 %.