scholarly journals Development of a Small Downdraft Biomass Gasifier for Developing Countries

2010 ◽  
Vol 3 (1) ◽  
pp. 51 ◽  
Author(s):  
M. A. Chawdhury ◽  
K. Mahkamov
Keyword(s):  
Developing Countries ◽  
Renewable Energy ◽  
Agricultural Sector ◽  
Calorific Value ◽  
Biomass Gasification ◽  
Appropriate Technology ◽  
Wood Chips ◽  
Steel Pipes ◽  
Cold Gas Efficiency ◽  
Gas Efficiency

Biomass gasification has been receiving increasing attention as a potential renewable energy source for the last few decades. This attempt involved designing, developing and testing a small downdraft biomass gasifier JRB-1 (6-7 kW) at Durham University, UK. The gasifier was built of stainless steel pipes, sheets and other fittings and tested for wood chips and pellets. The composition, moisture content and consumption of biomass feedstock (3.1 kg/hr for wood chips, 2.9 kg/hr for pellets), temperature inside the reaction zone (950-1150 oC), primary air flow rate (0.0015 m3/s) and exit temperature of the producer gas (180-220 oC) was measured. The main constituents of syngas included nitrogen (50-56%), carbon monoxide (19-22%), hydrogen (12-19%), carbon dioxide (10-12%) and a small amount of methane (1-2%). These results were used in Engineering Equation Solver (EES) software to obtain the lower calorific value of syngas (4424-5007 kJ/m3) and cold gas efficiency (62.5-69.4%) of the gasifier, which were found close to the calculated values. Again the thermal efficiency was calculated as 90.1-92.4%. Being comparatively easy to build, downdraft gasifiers like JRB-1 are likely to be the most appropriate technology for developing countries as a source of decentralized power supply and for development in agricultural sector. Keywords:  Biomass gasification; Syngas; Emission; Renewable energy.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i1.5613                J. Sci. Res. 3 (1), 51-64 (2011)

scholarly journals Studies on the Gasification Performance of Sludge Cake Pre-Treated by Hydrothermal Carbonization

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1442 ◽  
Author(s):  
Sang Yeop Lee ◽  
Se Won Park ◽  
Md Tanvir Alam ◽  
Yean Ouk Jeong ◽  
Yong-Chil Seo ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Moisture Content ◽  
Energy Recovery ◽  
Calorific Value ◽  
Hydrothermal Carbonization ◽  
Treatment Technique ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Sludge Cake ◽  
Gas Efficiency

Proper treatment and careful management of sewage sludge are essential because its disposal can lead to adverse environmental impacts such as public health hazards, as well as air, soil, and water pollution. Several efforts are being made currently not only to safely dispose of sewage sludge but also to utilize it as an energy source. Therefore, in this study, initiatives were taken to valorize sewage sludge cake by reducing the moisture content and increasing the calorific value by applying a hydrothermal treatment technique for efficient energy recovery. The sludge cake treated at 200 °C for 1 h was found to be the optimum condition for hydrothermal carbonization, as, in this condition, the caloric value of the treated sludge increased by 10% and the moisture content removed was 20 wt.%. To recover energy from the hydrothermally treated sludge, a gasification technology was applied at 900 °C. The results showed that the product gas from hydrothermally treated sludge cake had a higher lower heating value (0.98 MJ/Nm3) and higher cold gas efficiency (5.8%). Furthermore, compared with raw sludge cake, less tar was generated during the gasification of hydrothermally treated sludge cake. The removal efficiency was 28.2%. Overall results depict that hydrothermally treated sewage sludge cake could be a good source of energy recovery via the gasification process.

Simulation of Enriched Air-Steam Biomass Gasification in a Bubbling Fluidized Bed Gasifier

2014 ◽  
Vol 699 ◽  
pp. 510-515
Author(s):  
Miao Miao Niu ◽  
Ya Ji Huang ◽  
Bao Sheng Jin
Keyword(s):  
Fluidized Bed ◽  
Steam Injection ◽  
Biomass Gasification ◽  
Carbon Conversion ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Oxygen Percentage ◽  
Bubbling Fluidized Bed ◽  
Gas Efficiency ◽  
Cold Gas

A model was developed for the enriched air-steam biomass gasification in a bubbling fluidized bed (BFB) gasifier using Aspen Plus. Restricted equilibrium method was used to eliminate the deviation caused by the diffusion effect of gas-particle. The model has been divided into three stages (drying and pyrolysis, partial combustion and gasification) for predicting the gasifier performance. Simulation results for gas composition, carbon conversion and cold gas efficiency versus oxygen percentage and steam to biomass ratio (S/B) were compared with the experimental results. Higher oxygen percentage improves the gasification process, increases the production of H2 and CO and results in better gasification efficiency. With increasing oxygen percentage, the production of CO2 and CH4 show decreasing trends. Steam injection enhances the H2 and CO2 production but decreases CO and CH4 production. Carbon conversion presents a slight decrease trend over the S/B range, while cold gas efficiency is first constant and then decreased.

scholarly journals Coal Type, Temperature and Gasifiying Agent Effects on Low-Rank Coal Gasification Using CFD Method

CFD letters ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 111-127
Author(s):  
Kamariah Md Isa ◽  
Kahar Osman ◽  
Nik Rosli Abdullah ◽  
Nor Fadzilah Othman ◽  
Nurulnatisya Ahmad
Keyword(s):  
Coal Gasification ◽  
Calorific Value ◽  
Low Rank ◽  
Fluidised Bed ◽  
Low Rank Coal ◽  
Cold Gas Efficiency ◽  
Different Temperatures ◽  
Lower Temperature ◽  
Cfd Method ◽  
Gas Efficiency

Low-Rank Coal (LRC) gasification utilising Fluidised Bed Gasifier (FBG) is more efficient for LRC that has higher reactivity, moisture, tar, volatile, and ash content but lower calorific value compared to other types of coals. This work investigated the application of Computational Fluid Dynamics (CFD) in simulating LRC gasification under different temperatures which is lower (873K), normal (973K) and higher (1073K) temperature atmosphere. Besides that, the effect of LRC type and gasifying agents on the producer gas CO+H2 composition, Lower Heating Value (LHV) and Cold Gas Efficiency (CGE) were also studied using High-rank Coal (HRC) as comparison. The results obtained showed that LRC gasification using oxygen increased LHV and CGE. Lower temperature gasification using oxygen at 873 increased CO+H2, LHV and CGE for LRC compared to higher temperatures at 973K and 1073K. This prediction suggests that LRC gasification using oxygen at lower temperature increases the LRC gasification efficiency.

scholarly journals Simulation of Cotton Stalks for Syngas Generation Using CO2 and Air as Gasifying Agents

2020 ◽  
Vol 39 (2) ◽  
pp. 371-379
Author(s):  
Ghulamullah Maitlo ◽  
Rasool Bux Mahar ◽  
Khan Mohammad Brohi
Keyword(s):  
Biomass Gasification ◽  
Cotton Stalk ◽  
Heating Value ◽  
Entrained Flow ◽  
Cold Gas Efficiency ◽  
Cotton Stalks ◽  
Lower Heating Value ◽  
Entrained Flow Gasifier ◽  
Gas Efficiency ◽  
Lower Heating

Gasification of coal and biomass using CO2 and air mixture as a carrier gas offers an encouraging way to eliminate the shortage of energy and reduce carbon dioxide emissions. In the present study, the EulerianLagrangian approach was applied to understand the thermochemical conversion behavior of feedstock in entrained flow gasifier. Commercial CFD (Computational Fluid Dynamics) code ANSYS FLUENT®14 was used for the simulation purpose. It was observed that with variation in the CO2 in the air and the CO2 to cotton stalk ratio had a meaningful effect on gasification performance. The different ratios of air and CO2 in varying percentages such as 20% CO2, 30% CO2, 40% CO2, 50% CO2, 60% CO2, 70% CO2 and remaining percentages of air were introduced in entrained flow gasifier. With the increase in CO2 to cotton stalk ratio, the concentration of H2 and CO2 decreased whereas as the concentration of CO improved. It is revealed that mole fraction of CO and CH4 attained maximum when CO2% in the air was 50% and H2 mole fraction was observed maximum at a CO2% in the air was 30%. At 50% CO2 mixture in air, the maximum lower heating value and cold gas efficiency were observed. Therefore, the optimum situation might be 50% percentage CO2 in the gasifying agent for this entrained flow gasifier. Hence an increase in CO and H2, the cold gas efficiency and lower heating value reached the maximum. However, this study provides an appropriate route for energy production using cotton stalks as raw material and will help in designing and operation of the entrained flow reactor. The simulations indicate the thermodynamic limits of gasification and allow for the formulation of the general principles ruling this process. Moreover, no literature is available for the parametric investigations of Pakistani biomass gasification using entrained-flow gasifier. So this is a novel work for Pakistan and will be treated as foundation work for biomass gasification in the country.

scholarly journals Effects of Oxygen Enrichment in Air Oxidants on Biomass Gasification Efficiency and the Reduction of Tar Emissions

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2664 ◽  
Author(s):  
Se-Won Park ◽  
Sang-Yeop Lee ◽  
Yean-Ouk Jeong ◽  
Gun-Ho Han ◽  
Yong-Chil Seo
Keyword(s):  
Large Scale ◽  
Biomass Gasification ◽  
Oxygen Enrichment ◽  
Producer Gas ◽  
Cold Gas Efficiency ◽  
Tar Reduction ◽  
Gasification Efficiency ◽  
Combustible Gases ◽  
Gas Efficiency ◽  
Enrichment Condition

This study applied oxygen-enrichment conditions to remove tar (the main problem in biomass gasification) and increase gasification efficiency. Experiments on oxygen-enrichment conditions were conducted at oxygen concentrations of 21%, 25%, 30%, and 35% in oxidants. This was expected to increase the partial oxidation reaction in gasification reactions, thus leading to thermal decomposition of tar in producer gas. The decomposed tar was expected to be converted into syngas or combustible gases in the producer gas. The results were as follows: Tar-reduction efficiency was 72.46% at 30% oxygen enrichment compared to the standard 21% enrichment condition. In addition, the concentrations of syngas and combustible gases in the producer gas tended to increase. Therefore, the 30% oxygen-enrichment condition was optimal, resulting in 78.00% for cold gas efficiency and 80.24% for carbon conversion efficiency. The application of oxygen enrichment into the lab-scale gasification system clearly reduced the concentration of tar and tended to increase some indexes of gasification efficiency, thus suggesting the usefulness of this technique in large-scale biomass gasification operations.

scholarly journals Comparative Study of Municipal Solid Waste Fuel and Refuse Derived Fuel in the Gasification Process Using Multi Stage Downdraft Gasifier

2021 ◽  
Vol 4 (2) ◽  
pp. 97-103
Author(s):  
Sigit Mujiarto ◽  
Bambang Sudarmanta ◽  
Hamzah Fansuri ◽  
Arif Rahman Saleh
Keyword(s):  
Alternative Energy ◽  
Performance Indicator ◽  
Calorific Value ◽  
Alternative Energy Source ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Multi Stage ◽  
Refuse Derived Fuel ◽  
Gas Efficiency ◽  
Cold Gas

Municipal solid waste (MSW)  is a type of general waste that includes households, traditional markets, commercial areas, and the rest from public facilities, schools, offices, roads, and so on. Refuse Derived Fuel (RDF) is obtained from the remnants of MSW which cannot be used anymore, which is flammable waste and is separated from parts that are difficult to burn through the process of chopping, sifting, and air classification. RDF has potential as an alternative energy source. In this study, RDF fuel was compared with MSW fuel both by proximate and calorific value, then the gasification process was carried out using a multi-stage downdraft gasifier to see gasification performance indicators such as syngas composition, LHV, cold gas efficiency, and tar concentration. The results showed that the gasification performance indicator for MSW biomass resulted in the syngas composition of CO = 19.08% v, H2 = 10.89% v, and CH4 = 1.54% v. The calorific value (Low Heating Value, LHV ) of syngas is 4,137 kJ/kg, cold gas efficiency is 70.14%, and tar content is 57.29 mg/Nm3. Meanwhile, RDF obtained the composition of CO gas: 18.68% v, H2: 9.5446% v, and CH4: 0% v. The maximum LHV syngas is 3365.08 kJ/kg, cold gas efficiency is 57.19 % and the smallest tar content is 80.24 mg/Nm3. When compared to RDF, MSW produces a better gasification performance indicator. However, RDF can still be used as an alternative energy source using the gasification process. The results of this study can be used to optimize the further RDF gasification process.

scholarly journals Investigation of an Intensified Thermo-Chemical Experimental Set-Up for Hydrogen Production from Biomass: Gasification Process Performance—Part I

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1104
Author(s):  
Donatella Barisano ◽  
Giuseppe Canneto ◽  
Francesco Nanna ◽  
Antonio Villone ◽  
Emanuele Fanelli ◽  
...  
Keyword(s):  
Biomass Gasification ◽  
Gas Filtration ◽  
Heating Value ◽  
Gaseous Products ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Filtration System ◽  
Filtration Step ◽  
Set Up ◽  
Gas Efficiency

Biomass gasification for energy purposes has several advantages, such as the mitigation of global warming and national energy independency. In the present work, the data from an innovative and intensified steam/oxygen biomass gasification process, integrating a gas filtration step directly inside the reactor, are presented. The produced gas at the outlet of the 1 MWth gasification pilot plant was analysed in terms of its main gaseous products (hydrogen, carbon monoxide, carbon dioxide, and methane) and contaminants. Experimental test sets were carried out at 0.25–0.28 Equivalence Ratio (ER), 0.4–0.5 Steam/Biomass (S/B), and 780–850 °C gasification temperature. Almond shells were selected as biomass feedstock and supplied to the reactor at approximately 120 and 150 kgdry/h. Based on the collected data, the in-vessel filtration system showed a dust removal efficiency higher than 99%-wt. A gas yield of 1.2 Nm3dry/kgdaf and a producer gas with a dry composition of 27–33%v H2, 23–29%v CO, 31–36%v CO2, 9–11%v CH4, and light hydrocarbons lower than 1%v were also observed. Correspondingly, a Low Heating Value (LHV) of 10.3–10.9 MJ/Nm3dry and a cold gas efficiency (CGE) up to 75% were estimated. Overall, the collected data allowed for the assessment of the preliminary performances of the intensified gasification process and provided the data to validate a simulative model developed through Aspen Plus software.

Gasification: An alternative solution for energy recovery and utilization of vegetable market waste

2016 ◽  
Vol 35 (3) ◽  
pp. 276-284 ◽  
Author(s):  
Sunil L Narnaware ◽  
NSL Srivastava ◽  
Samir Vahora
Keyword(s):  
Power Generation ◽  
Energy Recovery ◽  
Combustion Engine ◽  
Calorific Value ◽  
Maximum Load ◽  
Thermochemical Conversion ◽  
Small Scale ◽  
Vegetable Waste ◽  
Cold Gas Efficiency ◽  
Gas Efficiency

Vegetables waste is generally utilized through a bioconversion process or disposed of at municipal landfills, dumping sites or dumped on open land, emitting a foul odor and causing health hazards. The presents study deals with an alternative way to utilize solid vegetable waste through a thermochemical route such as briquetting and gasification for its energy recovery and subsequent power generation. Briquettes of 50 mm diameter were produced from four different types of vegetable waste. The bulk density of briquettes produced was increased 10 to 15 times higher than the density of the dried vegetable waste in loose form. The lower heating value (LHV) of the briquettes ranged from 10.26 MJ kg−1 to 16.60 MJ kg−1 depending on the type of vegetable waste. The gasification of the briquettes was carried out in an open core downdraft gasifier, which resulted in syngas with a calorific value of 4.71 MJ Nm−3 at the gasification temperature between 889°C and 1011°C. A spark ignition, internal combustion engine was run on syngas and could generate a maximum load up to 10 kWe. The cold gas efficiency and the hot gas efficiency of the gasifier were measured at 74.11% and 79.87%, respectively. Energy recovery from the organic vegetable waste was possible through a thermochemical conversion route such as briquetting and subsequent gasification and recovery of the fuel for small-scale power generation.

Evaluasi Prediksi Higher Heating Value (HHV) Biomassa Berdasarkan Analisis Proksimat

2020 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Made Dirgantara ◽  
Karelius Karelius ◽  
Marselin Devi Ariyanti, Sry Ayu K. Tamba
Keyword(s):  
Renewable Energy ◽  
Natural Gas ◽  
Key Words ◽  
Critical Analysis ◽  
Fossil Fuels ◽  
Calorific Value ◽  
Proximate Analysis ◽  
Heating Value ◽  
Bomb Calorimeter ◽  
Hhv Prediction

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat  Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate 

CURRENT STATE AND PROSPECTS FOR THE DEVELOPMENT OF BIOGAS ENERGY IN UZBEKISTAN

2020 ◽  
Vol 2 (7) ◽  
pp. 171-184
Author(s):  
Z. U. SAIPOV ◽  
◽  
G. A. ARIFDZHANOV ◽  
Keyword(s):  
Renewable Energy ◽  
Organic Waste ◽  
Agricultural Sector ◽  
Renewable Energy Sources ◽  
Energy Resources ◽  
Agricultural Producers ◽  
Biogas Plants ◽  
The Republic ◽  
Rural Producers ◽  
Agricultural Regions

Energy is one of the main pillars of the state’s economy, which is currently facing serious problems due to depletion of mineral energy resources and the threatening environment. As a result, presently around the world there is a rapid growth and development of energy-efficient technologies and the use of renewable energy sources (RES), providing an increase in energy resources, as well as environmental and social effects. One of the most relevant and promising areas of renewable energy development is the disposal and processing of organic waste in biogas plants, and this is particularly relevant in agricultural regions. In this regard, this paper considers the state and prospects for the development of bioenergy in agricultural regions of Uzbekistan, where half of the population of the republic lives. The potential of organic waste from livestock and poultry farming of the agricultural sector was determined, and it was revealed that the use of biogas plants for the disposal of manure and litter is clearly a profitable production and requires close attention from rural producers. The introduction of biogas technologies for the bulk of agricultural producers is an urgent task, that will ensure not only a solution to the waste problem, but it will also provide a solution to energy, agricultural, environmental and social problems in rural regions of the republic.

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