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

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.

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.


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%.


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 ◽  
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.


Author(s):  
John P. Foote ◽  
Paul Pillsbury ◽  
Frank C. Morton

A gas turbine combuster has been designed to burn coal derived syngas with a lower heating value (LHV) of less than 3700 kJ/Nm3 (100 Btu/scf). The new Piloted Syngas Burner (PSB) is designed to operate with a continuous propane pilot during syngas firing to maintain flame stability. The amount of propane supplied to the pilot can be adjusted in response to a burner noise measurement or other indications of flame stability, with the ultimate goal of operating only on syngas. The burner has a very large combustion volume to promote burnout of less than 3700 kJ/Nm3 syngas and incorporates a high-efficiency liner cooling scheme, to allow utilization of high energy fuel for starting and backup. The PSB is being tested at the U.S. Department of Energy’s (DOE) Power Systems Development Facility (PSDF) in Wilsonville, AL, where it replaces the usual six combustor cans in a Rolls-Royce Allison 501-KM gas turbine. Syngas is supplied to the burner from a Transport Reactor coal gasifier. Initial operation of the PSB on propane startup fuel was successfully conducted during February 2003, and initial operation on syngas was successfully conducted during October 2003. The paper will discuss the results of the initial propane and syngas operation. The PSB is expected to be operated extensively in 2004.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4608
Author(s):  
Jingjing He ◽  
Hao Chen ◽  
Xin Su ◽  
Bin Xie ◽  
Quanwei Li

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.


Author(s):  
Joshua A. Bittle ◽  
Jesse K. Younger ◽  
Timothy J. Jacobs

Biodiesel remains an alternative fuel of interest for use in diesel engines. A common characteristic of biodiesel, relative to petroleum diesel, is a lowered heating value (or per mass energy content of the fuel). For same torque engine comparisons, the lower heating value translates into a higher brake specific fuel consumption (amount of fuel consumed per unit of power produced). The efficiency at which fuel energy converts into work energy, however, may remain unchanged. In this experimental study, evaluating nine unique engine operating conditions, the brake fuel conversion efficiency (an assessor of fuel energy to work energy efficiency) remains unchanged between 100% petroleum diesel fuel and 100% biodiesel fuel (palm olein) at all conditions, except for high load conditions. Several parameters may affect the brake fuel conversion efficiency, including heat loss, mixture properties, pumping work, friction, combustion efficiency, and combustion timing. This article describes a study that evaluates how the aforementioned parameters may change with the use of biodiesel and petroleum diesel, and how these parameters may result in differences in the brake fuel conversion efficiency.


2021 ◽  
Author(s):  
Randall Boehm ◽  
Zhibin Yang ◽  
David Bell ◽  
John Feldhausen ◽  
Joshua Heyne

A detailed assessment is presented on the calculation and uncertainty of the lower heating value (net heat of combustion) of conventional and sustainable aviation fuels, from hydrocarbon class concentration measurements, reference molecular heats of formation, and the uncertainties of these reference heats of formation. Calculations using this paper’s method and estimations using ASTM D3338 are reported for 17 fuels of diverse compositions and compared against reported ASTM D4809 measurements. All the calculations made by this method and the reported ASTM D4809 measurements agree (i.e., within 95% confidence intervals). The 95% confidence interval of the lower heating value of fuel candidates that are comprised entirely of normal- and iso-alkanes is less than 0.1 MJ/kg by the method described here, while high cyclo-alkane content leads to 95% confidence bands that approach 0.2 MJ/kg. Taking a possible bias into account, the accuracy and precision of the method described in this work could be as high as 0.23 MJ/kg for some samples.


1985 ◽  
Vol 64 (9) ◽  
pp. 716-733
Author(s):  
Takehiko FURUSAWA ◽  
Toshinori KOJIMA ◽  
Seiji TOKAWA ◽  
Shuichi TANAKA ◽  
Takuya KAWANISHI ◽  
...  

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