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 ◽  
...  

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.

2012 ◽  
Vol 512-515 ◽  
pp. 575-578
Author(s):  
Hsien Chen ◽  
Chiou Liang Lin ◽  
Wun Yue Zeng ◽  
Zi Bin Xu

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.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7384
Author(s):  
M. Shahabuddin ◽  
Sankar Bhattacharya

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%.


Author(s):  
Ghulamullah Maitlo ◽  
Rasool Bux Mahar ◽  
Khan Mohammad Brohi

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.


2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Krongkaew Laohalidanond ◽  
Somrat Kerdsuwan ◽  
Kiran Raj Goud Burra ◽  
Jinhu Li ◽  
Ashwani K. Gupta

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.


2020 ◽  
Vol 9 (1) ◽  
pp. 30-35
Author(s):  
Hendriyana Hendriyana

Rice husk is the waste from agriculture industries that has high potential to produce heat and electricity through the gasification process. Air suction mode is new development for updraft rice husk gasification, where blower are placed at output of gasifier. The objective of this research is to examine these new configuration at several equivalence ratio. The equivalence ratio was varied at 32% and 49% to study temperature profile on gasifier, producer gas volumetric flow rate, composition of producer gas, producer gas heating value, cold gas efficiency and carbon conversion. The time needed to consume rice husk and reach an oxidation temperature of more than 700oC for equivalence ratio of 49% is shorter than 32%. Producer gas rate production per unit weight of rice husk increase from  2.03 Nm3/kg and 2.36 Nm3/kg for equivalence ratio of 32% and 49%, respectively. Composition producer gas for equivalence ratio of 32% is 17.67% CO, 15.39% CO2, 2.87% CH4, 10.62% H2 and 53.45% N2 and 49% is 19.46% CO, 5.94% CO2, 0.90% CH4, 3.46% H2 and 70.24% N2. Producer gas heating value for equivalence ratio 32% and 49% is 4.73 MJ/Nm3 and 3.27 MJ/Nm3, respectively. Cold gas efficiency of the gasifier at equivalence ratio 32% is 69% and at 49% is 55%.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 102 ◽  
Author(s):  
Francesco Gallucci ◽  
Raffaele Liberatore ◽  
Luca Sapegno ◽  
Edoardo Volponi ◽  
Paolo Venturini ◽  
...  

This work aims to study the influence of an oxidant agent on syngas quality. A series of tests using air and steam as oxidant agents have been performed and the results compared with those of a pyrolysis test used as a reference. Tests were carried out at Sapienza University of Rome, using an updraft reactor. The reactor was fed with hazelnut shells, waste biomass commonly available in some parts of Italy. Temperature distribution, syngas composition and heating value, and producible energy were measured. Air and steam gasification tests produced about the same amount of syngas flow, but with a different quality. The energy flow in air gasification had the smallest measurement during the experiments. On the contrary, steam gasification produced a syngas flow with higher quality (13.1 MJ/Nm3), leading to the best values of energy flow (about 5.4 MJ/s vs. 3.3 MJ/s in the case of air gasification). From the cold gas efficiency point of view, steam gasification is still the best solution, even considering the effect of the enthalpy associated with the steam injected within the gasification reactor.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 688 ◽  
Author(s):  
Mauro Villarini ◽  
Vera Marcantonio ◽  
Andrea Colantoni ◽  
Enrico Bocci

The present paper presents a study of biomass waste to energy conversion using gasification and internal combustion engine for power generation. The biomass waste analyzed is the most produced on Italian soil, chosen for suitable properties in the gasification process. Good quality syngas with up to 16.1% CO–4.3% CH4–23.1% H2 can be produced. The syngas lower heating value may vary from 1.86 MJ/ Nm3 to 4.5 MJ/Nm3 in the gasification with air and from 5.2 MJ/ Nm3 to 7.5 MJ/Nm3 in the gasification with steam. The cold gas efficiency may vary from 16% to 41% in the gasification with air and from 37% to 60% in the gasification with steam, depending on the different biomass waste utilized in the process and the different operating conditions. Based on the sensitivity studies carried out in the paper and paying attention to the cold gas efficiency and to the LHV, we have selected the best configuration process for the best syngas composition to feed the internal combustion engine. The influence of syngas fuel properties on the engine is studied through the electrical efficiency and the cogeneration efficiency.


2012 ◽  
Vol 66 (7) ◽  
Author(s):  
Afsin Gungor ◽  
Murat Ozbayoglu ◽  
Cosku Kasnakoglu ◽  
Atilla Biyikoglu ◽  
Bekir Uysal

AbstractIn this parametric study, the effects of coal and oxidiser type, air-to-fuel ratio, steam-to-fuel ratio, reactor temperature, and pressure on H2 and CO amounts at the gasifier output, H2/CO, and higher heating value of the syngas produced have been calculated using a coal gasification model. Model simulations have been performed to identify the optimum values which are assumed to be 100 % for both cold gas efficiency and carbon conversion efficiency in the gasification process. From this study, it may be observed that the moisture content of the coal type is of crucial importance for the air gasification process; the O2 content of similar coals (taking into consideration the moisture and H2 content) is of significant importance for the air gasification process. When compared with air gasification, air-steam gasification becomes a more effective coal gasification method. The optimum working condition for air-steam gasification is to carry out the process at one atmosphere. High gasifier temperatures are not needed for the air-steam gasification of coal.


Author(s):  
Mehdi Borji ◽  
Kazem Atashkari ◽  
Saba Ghorbani ◽  
Nader Nariman-Zadeh

Numerical analysis of combined heat and power plant consisting of a solid oxide fuel cell and autothermal gasification system has been made for several cases of different composition of fuel relevant to air and steam blown biomass gasification process. Wet wood is fed to the fixed-bed downdraft gasifier and gaseous fuel is produced then after gas cleaning and conditioning can be used in solid oxide fuel cells. The integrated plant is investigated by thermodynamic modeling combining a one-dimensional model of direct internal intermediate planar type solid oxide fuel cell which allows monitoring the temperature gradients along the cell length in different operating conditions and a zero-dimensional autothermal gasifier. The solid oxide fuel cell mathematical model is developed based on gas species mass balances, energy balance, and an electrochemical model beside the kinetics describing internal reforming and water-gas shift reactions. Such a model can be integrated with adiabatic gasification modeling which includes atom balance conservation for assumed gas species and a modified thermodynamic equilibrium analysis. Both gasifier and solid oxide fuel cell models are verified against experimental and previous numerical data available in the literature. Two main parameters, namely modified equivalence ratio and air-to-steam ratio are investigated and the most important cycle parameters such as power, electric and combined heat and power efficiencies, temperature gradients along the cell length, and mole fractions of gaseous species of the produced fuel are analyzed. It has been revealed that any increase in air-to-steam ratio at fixed modified equivalence ratio leads to penalty on cold gas efficiency of the gasifier and both solid oxide fuel cell and combined heat and power plant electric efficiencies. Increased air-to-steam ratio at constant modified equivalence ratio produces a mixture with lower low heating value, higher steam-to-carbon ratio, rich in CO and lower in CH4 content. Under this condition the operating temperature of the cycle and solid oxide fuel cell increases and consequently improves the operating voltage of the cell and combined heat and power efficiency of the plant. On the other hand, results show that gasification with increased modified equivalence ratio at constant air-to-steam ratio produces mixtures richer in CH4 and CO, poorer in H2 with higher low heating value and cold gas efficiency, and lower steam-to-carbon ratio. Such condition improves the electric efficiency of the solid oxide fuel cell and the integrated plant, but the combined heat and power efficiency of the cycle decreases due to decreased operating temperature of the solid oxide fuel cell and the cycle.


2016 ◽  
Vol 25 (41) ◽  
pp. 41
Author(s):  
Juan Fernando Pérez-Bayer ◽  
Rolando Barrera-Zapata ◽  
Carlos Alberto Salazar-Jiménez

<p>The effect of coal rank (from sub-bituminous to semi-anthracite) and type of fuel feeding technology (slurry and dry) on the production of substitute natural gas (SNG) in entrained flow gasifiers is studied. Ten coals from important Colombian mines were selected. The process is modeled under thermochemical equilibrium using Aspen Plus, and its performance is evaluated in function of output parameters that include SNG heating value, Wobbe index, coal conversion efficiency, cold gas efficiency, process efficiency, global efficiency, and SNG production rate, among others. In descending order, the coal-to-SNG process improves energetically with the use of coals with: higher volatile-matter to fixed-carbon ratio, lower ash content, higher C+H/O ratio, and higher coal heating value. The overall energy efficiency of the slurry-feed technology (S-FT) to produce SNG by gasification is 17% higher than the dry-feed technology (D-FT), possibly as a consequence of the higher CH4 concentration in the syngas (around 7 vol. %) when the coal is fed as aqueous slurry. As the simulated SNG meets the natural gas (NG) quality standards in Colombia, the substitute gaseous fuel could be directly transported through pipelines. Therefore, the coal-to-SNG process is a technically feasible and unconventional alternative for NG production.</p>


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