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 Co-Gasification Characteristics of Coal and Biomass Using CO2 Reactant under Thermodynamic Equilibrium Modelling

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7384
Author(s):  
M. Shahabuddin ◽  
Sankar Bhattacharya
Keyword(s):  
Steady State ◽  
Thermodynamic Equilibrium ◽  
Operating Conditions ◽  
Heating Value ◽  
Entrained Flow ◽  
Cold Gas Efficiency ◽  
Lower Heating Value ◽  
Entrained Flow Gasifier ◽  
Gas Efficiency ◽  
Increasing Temperature

This study assessed the entrained flow co-gasification characteristics of coal and biomass using thermodynamic equilibrium modelling. The model was validated against entrained flow gasifier data published in the literature. The gasification performance was evaluated under different operating conditions, such as equivalence ratio, temperature, pressure and coal to biomass ratio. It is observed that the lower heating value (LHV) and cold gas efficiency (CGE) increase with increasing temperature until the process reaches a steady state. The effect of pressure on syngas composition is dominant only at non-steady state conditions (<1100 °C). The variation in syngas composition is minor up to the blending of 50% biomass (PB50). However, the PB50 shows a higher LHV and CGE than pure coal by 12%and 18%, respectively. Overall, biomass blending of up to 50% favours gasification performance with an LHV of 12 MJ/kg and a CGE of 78%.

Syngas Generation From Landfills Derived Torrefied Refuse Fuel Using a Downdraft Gasifier

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Krongkaew Laohalidanond ◽  
Somrat Kerdsuwan ◽  
Kiran Raj Goud Burra ◽  
Jinhu Li ◽  
Ashwani K. Gupta
Keyword(s):  
Hydrocarbon Fuel ◽  
High Energy ◽  
High Energy Density ◽  
Heating Value ◽  
Downdraft Gasifier ◽  
Cold Gas Efficiency ◽  
Lower Heating Value ◽  
Gas Efficiency ◽  
Lower Heating ◽  
Cold Gas

Abstract Landfill reclamation is a good solution to utilize the wasted land occupied by municipal solid waste dumpsites or landfill sites. This also offers a good means to recover valuable materials and form environmentally benign green refuse-derived fuel (RDF) for use in power production. However, due to the heterogenous composition of the wastes, it is crucial to homogenize and upgrade the waste hydrocarbon fuel properties. Torrefaction is a thermochemical process that utilizes low temperature and inert environment to drive off the moisture and volatile fractions present in wastes to form valuable fuel. This upgraded RDF from reclaimed landfills offer high energy density and favorable hydrophobicity for use as a fuel feedstock in gasification to produce syngas for power generation. The objectives of this study are to first upgrading the reclaimed landfill wastes to RDF using torrefaction followed by its conversion to form clean syngas in a downdraft gasifier. This study examines the effect of air ratio on syngas heating value and cold gas efficiency. A comparison is made on the syngas produced from gasification using reclaimed landfill wastes and torrefied RDF. Experiments were conducted using a 10 kg/h lab-scale downdraft gasifier. The air ratios examined were 0.22, 0.27, and 0.32. The results showed an optimum air ratio of 0.27 operated with a gasifier using torrefied RDF. The results showed improved syngas quality, in terms of syngas composition, lower heating value, and cold gas efficiency. The lower heating value of 4.22 MJ/Nm3 and the cold gas efficiency of 65.84% were achieved. The results showed that landfill mining can provide ultimate solution to get rid of dumped wastes from landfills using torrefaction for high-quality fuel followed by the recovery of green and clean syngas energy using gasification.

The Effect of Biomass Contents with Heavy Metal on Gasification Efficiency during Fluidized Bed Gasification Process

2012 ◽  
Vol 512-515 ◽  
pp. 575-578
Author(s):  
Hsien Chen ◽  
Chiou Liang Lin ◽  
Wun Yue Zeng ◽  
Zi Bin Xu
Keyword(s):  
H2 Production ◽  
Heating Value ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Zn Concentration ◽  
Lower Heating Value ◽  
Gasification Efficiency ◽  
Waste Gasification ◽  
Gas Efficiency ◽  
Cu And Zn

Catalysis was used to increase the H2 production, syngas heating value, enhanced carbon conversion efficiency and cold gas efficiency during gasification. Due to Cu and Zn were abundant in waste according to previous researches, this research discussed the effect of Cu and Zn on artificial waste gasification. The syngas composition and total lower heating value (LHV) were determined in this study. The results showed that the existence of Cu and Zn increased production of H2 and CO. However, the production of CH4 and CO2 decreased. At same time, total LHV was also increased. Additionally, the different Cu concentration affected gas composition and LHV, but the effect of Zn concentration was not significant.

scholarly journals Co-Gasification of Treated Solid Recovered Fuel Residue by Using Minerals Bed and Biomass Waste Blends

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2081
Author(s):  
Md Tanvir Alam ◽  
Se-Won Park ◽  
Sang-Yeop Lee ◽  
Yean-Ouk Jeong ◽  
Anthony De Girolamo ◽  
...  
Keyword(s):  
Low Cost ◽  
Biomass Waste ◽  
Heating Value ◽  
Pine Sawdust ◽  
Syngas Production ◽  
Cold Gas Efficiency ◽  
Natural Minerals ◽  
Lower Heating Value ◽  
Gas Efficiency ◽  
Bed Material

Solid recovered fuel (SRF) residue, which is leftovers from the SRF manufacturing process, usually is discarded in landfill because of its low heating value and high ash and moisture content. However, it could be used as a fuel after mechanical and biological treatment. Gasification experiments were conducted on treated SRF residue (TSRFR) to assess the viability of syngas production. Efforts were also made to improve the gasification performance by adding low-cost natural minerals such as dolomite and lime as bed material, and by blending with biomass waste. In the case of additive mineral tests, dolomite showed better performance compared to lime, and in the case of biomass blends, a 25 wt% pine sawdust blend with TSRFR showed the best performance. Finally, as an appropriate condition, a combined experiment was conducted at an equivalence ratio (ER) of 0.2 using a 25 wt% pine sawdust blend with TSRFR as a feedstock and dolomite as the bed material. The highest dry gas yield (1.81 Nm3/kg), with the highest amount of syngas (56.72 vol%) and highest lower heating value (9.55 MJ/Nm3) was obtained in this condition. Furthermore, the highest cold gas efficiency (48.64%) and carbon conversion rate (98.87%), and the lowest residue yield (11.56%), tar (0.95 g/Nm3), and gas pollutants content was observed.

The heating value of gas obtained from biomass gasification: A new method for its calculation or prediction

2002 ◽  
Vol 216 (6) ◽  
pp. 447-452 ◽  
Author(s):  
L Bomprezzi ◽  
P Pierpaoli ◽  
R Raffaelli
Keyword(s):  
Experimental Data ◽  
Statistical Analysis ◽  
Biomass Gasification ◽  
Empirical Correlation ◽  
Process Temperature ◽  
Heating Value ◽  
Lower Heating Value ◽  
Experimental Values ◽  
The One ◽  
Lower Heating

An empirical correlation is presented for calculating the lower heating value (LHV) of gases obtained from the gasification of the most common types of biomass. Four types of equation are considered (polynomial, power, exponential, and logarithmic), all containing the process temperature (maximum) parameter; they were obtained by interpolating experimental data available in the literature on the volumetric composition of the gas discharged by gasifiers. On the strength of a statistical analysis, it emerged that although all four were valid within the temperature range considered, the polynomial correlation was the one that came closest to the experimental values.

scholarly journals Comparison of Fuel Yield of Biomaterials Between Fast Pyrolysis and Gasification

2017 ◽  
Vol 4 ◽  
pp. 2-16
Author(s):  
Matthew Charles Stokes Hughes ◽  
Lachlan Mcfall ◽  
Matthew Christiansen ◽  
Nicholas Zepernick
Keyword(s):  
Fast Pyrolysis ◽  
High Carbon ◽  
Primary Methods ◽  
Heating Value ◽  
Cotton Stalks ◽  
Lower Heating Value ◽  
Bio Oil ◽  
Viable Method ◽  
Lower Heating ◽  
The Ideal

Pyrolysis is a viable method of extracting combustible fuels as gases or liquids from various, high carbon and hydrogen containing biomaterials. This Meta-study attempts to find the ideal combinations of processes for maximising biofuel output by comparing a range of biomaterials (cotton stalks, algae and peach scraps), put through the two primary methods of pyrolysis, through analysis of reactor type, Temperature, particle size and lower heating value achieved from biofuel output. It is proposed that the fast pyrolysis of Algae in a Fluidized bed reactor at a temperature of 550°C is the optimum combination of parameters for maximising biofuel output in terms of bio-oil yield and lower heating value (LHV) in kJ/kg.

scholarly journals Study on Simulation of Biomass Gasification for Syngas Production in a Fixed Bed Reactor

2018 ◽  
pp. 139-149
Author(s):  
Bedewi Bilal ◽  
M. RaviKumar ◽  
Solomon Workneh
Keyword(s):  
Moisture Content ◽  
Biomass Gasification ◽  
Fixed Bed Reactor ◽  
Coffee Bean ◽  
Heating Value ◽  
Reactor Volume ◽  
Gasification Process ◽  
Lower Heating Value ◽  
Gasification Temperature ◽  
Lower Heating

This study was focusing on the simulation of the biomass (coffee bean husk and rice husk) gasification process based on the kinetics of the gasifier and to investigate the produced syngas composition. The ASPEN PLUS simulator was used to investigate the effect of operating parameters on composition of product gas. The gasification process usually begins with the drying process, and then followed by pyrolysis. The pyrolysis process leads to breaking down of the biomass into solid matter, gaseous mixture (mainly CO2, CO, CH4 and H2) and liquid matter. The main focus on biomass gasification process is to efficiently convert the entire char constituent into gaseous product of the syngas by using either steam or CO2. The simulations include; gasification temperature, pressure, reactor volume, Equivalence ratio and moisture content have been investigated. From the result of sensitivity analysis increase the temperature the production of H2 and CO and the increase of moisture content of the biomass the lower heating value of the producer gas decrease. Based on the obtained result the maximum lower heating value of syngas was obtained at the gasification temperature of 8000C, steam to biomass ratio of 0.1, pressure of 1 bar, 0.05 of moisture content and 0.02 m3 of reactor volume.

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.

scholarly journals Combustion Study of Polyoxymethylene Dimethyl Ethers and Diesel Blend Fuels on an Optical Engine

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4608
Author(s):  
Jingjing He ◽  
Hao Chen ◽  
Xin Su ◽  
Bin Xie ◽  
Quanwei Li
Keyword(s):  
Soot Formation ◽  
Comprehensive Evaluation ◽  
Chemical Properties ◽  
Heating Value ◽  
Optical Engine ◽  
Leading Role ◽  
Combustion Duration ◽  
Polyoxymethylene Dimethyl Ethers ◽  
Lower Heating Value ◽  
Lower Heating

Polyoxymethylene dimethyl ethers (PODE) are a newly appeared promising oxygenated alternative that can greatly reduce soot emissions of diesel engines. The combustion characteristics of the PODE and diesel blends (the blending ratios of PODE are 0%, 20%, 50% and 100% by volume, respectively) are investigated based on an optical engine under the injection timings of 6, 9, 12 and 15-degree crank angles before top dead center and injection pressures of 100 MPa, 120 MPa and 140 MPa in this study. The results show that both the ignition delay and combustion duration of the fuels decrease with the increasing of PODE ratio in the blends. However, in the case of the fuel supply of the optical engine being fixed, the heat release rate, cylinder pressure and temperature of the blend fuels decrease with the PODE addition due to the low lower heating value of PODE. The addition of PODE in diesel can significantly reduce the integrated natural flame luminosity and the soot formation under all injection conditions. When the proportion of the PODE addition is 50% and 100%, the chemical properties of the blends play a leading role in soot formation, while the change of the injection conditions have an inconspicuous effect on it. When the proportion of the PODE addition is 20%, the blend shows excellent characteristics in a comprehensive evaluation of combustion and soot reduction.

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