scholarly journals Process Simulation of Co-Gasification of Raw Municipal Solid Waste and Bituminous Coal in CO2/O2 Atmosphere

2020 ◽  
Vol 10 (6) ◽  
pp. 1921
Author(s):  
Guangchao Ding ◽  
Boshu He
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bituminous Coal ◽  
Operating Conditions ◽  
Air Separation ◽  
Co2 Absorption ◽  
Separation Unit ◽  
Cold Gas Efficiency ◽  
Shift Reaction ◽  
Gasification Temperature

An integrated CO2/O2 co-gasification system of municipal solid waste (MSW) and bituminous coal (BC) with CO2 capture was developed and simulated by the Aspen plus, which mainly consisted of three processes: air separation unit, co-gasification system, and CO2 absorption unit. In addition, raw syngas composition, cold gas efficiency (CGE), and overall energy efficiency (OEE) of the entail system were evaluated in detail with respect to the main operating parameters (gasification temperature, T; oxygen equivalence ratio, Ro; mole of CO2 to carbon ratio, Rc; and the MSW blending ratio, RM). The results indicated that the addition of BC improved the gasification of MSW. Higher gasification temperature increased CGE and OEE. Increasing the Rc ratio led to the decrease of H2 mole fraction due to the enhanced reverse water-gas shift reaction. In addition, the CGE and OEE of the system decreased with increasing RM. From the analyses of the parameters, the most optimal operating conditions were set as T = 900 °C, Ro = 0.2, Rc = 0.5, and RM = 0.6, and the corresponding OEE of the system reached 0.57. The system can achieve a large processing capacity of MSW at the cost of the efficiency loss of this condition.

Techno-Economic Evaluation of Pressurized Oxy-Fuel Combustion Systems

2010 ◽  
Author(s):  
Jongsup Hong ◽  
Ahmed F. Ghoniem ◽  
Randall Field ◽  
Marco Gazzino
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Carbon Dioxide Capture ◽  
Fuel Combustion ◽  
Economic Feasibility ◽  
Operating Conditions ◽  
Air Separation ◽  
Separation Unit ◽  
Coal Price

Oxy-fuel combustion coal-fired power plants can achieve significant reduction in carbon dioxide emissions, but at the cost of lowering their efficiency. Research and development are conducted to reduce the efficiency penalty and to improve their reliability. High-pressure oxy-fuel combustion has been shown to improve the overall performance by recuperating more of the fuel enthalpy into the power cycle. In our previous papers, we demonstrated how pressurized oxy-fuel combustion indeed achieves higher net efficiency than that of conventional atmospheric oxy-fuel power cycles. The system utilizes a cryogenic air separation unit, a carbon dioxide purification/compression unit, and flue gas recirculation system, adding to its cost. In this study, we perform a techno-economic feasibility study of pressurized oxy-fuel combustion power systems. A number of reports and papers have been used to develop reliable models which can predict the costs of power plant components, its operation, and carbon dioxide capture specific systems, etc. We evaluate different metrics including capital investments, cost of electricity, and CO2 avoidance costs. Based on our cost analysis, we show that the pressurized oxy-fuel power system is an effective solution in comparison to other carbon dioxide capture technologies. The higher heat recovery displaces some of the regeneration components of the feedwater system. Moreover, pressurized operating conditions lead to reduction in the size of several other critical components. Sensitivity analysis with respect to important parameters such as coal price and plant capacity is performed. The analysis suggests a guideline to operate pressurized oxy-fuel combustion power plants in a more cost-effective way.

High-solids anaerobic digestion: comparison of three pilot scales

2008 ◽  
Vol 58 (9) ◽  
pp. 1757-1763 ◽  
Author(s):  
J. Guendouz ◽  
P. Buffière ◽  
J. Cacho ◽  
M. Carrère ◽  
J.-P. Delgenes
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Methane Production ◽  
Operating Conditions ◽  
High Solids ◽  
Dry Digestion ◽  
Mesophilic Conditions ◽  
Production Efficiencies

Two experiments were undertaken in three different experimental set-ups in order to compare them: an industrial 21-m3 pilot reactor, a new 40-ℓ laboratory pilot reactor and bmp type plasma bottles. Three consecutive batch dry digestion tests of municipal solid waste were performed under mesophilic conditions with the same feedstock in all vessels. Biogas and methane production at the end of the tests were similar (around 200 m3 CH4STP/tVS) for both pilot reactors and were different from the bottle tests. The dynamics of methane production and VFA accumulation concurred. However, the maximal levels of VFA transitory accumulation varied between reactors and between runs in a same reactor. Ammonia levels were similar in both reactors. These results show that the new reactor accurately imitates the conditions found in the larger one. Adaptation of microorganisms to the waste and operating conditions was also pointed out along the consecutive batches. Thermophilic semi-continuous tests were performed in both reactors with similar conditions. The methane production efficiencies were similar.

Microwave Torrefaction of Moist Municipal Solid Waste (MSW) Pellets with the Addition of Char from Agricultural Residues

2017 ◽  
Vol 757 ◽  
pp. 156-160
Author(s):  
Prodpran Siritheerasas ◽  
Phichayanan Waiyanate ◽  
Hidetoshi Sekiguchi ◽  
Satoshi Kodama
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bituminous Coal ◽  
Volatile Matter ◽  
Agricultural Residues ◽  
Microwave Oven ◽  
Microwave Absorber ◽  
Mass Yield ◽  
Heating Value ◽  
Microwave Absorbers

An investigation of the effect of the addition of char from agricultural residues on the torrefaction of moist municipal solid waste (MSW) pellets (40 wt.% moisture) was carried out in a microwave oven (500-800 W for 4-12 minutes). Char from agricultural residues, including corncob, palm shell, straw, and bagasse, was used as the microwave absorbers to enhance the absorption of microwave irradiation. It was found that the addition of char from bagasse yielded the lowest remaining mass (or mass yield) and volatile matter (VM) content, but the highest temperature and heating value, of the torrefied MSW pellet. Moisture in the MSW pellet with or without the addition of microwave absorber was completely removed after being torrefied for 8-12 minutes. The VM contents remained in the MSW pellets with the addition of microwave absorbers were lower than that in the MSW pellet without the addition of microwave absorber. The addition of microwave absorbers led to an increase in carbon (C) content but a decrease in oxygen (O) content of the torrefied MSW pellets, compared to those of the raw MSW pellet. The heating values of the torrefied MSW pellets with the addition of microwave absorbers were equivalent to that of sub-bituminous coal, enhanced from that of the raw MSW pellet, which was lower than that of lignite.

Prediction Rules for Biogas Valorisation in Municipal Solid Waste Landfills

1993 ◽  
Vol 27 (2) ◽  
pp. 235-241 ◽  
Author(s):  
B. Marticorena ◽  
A. Attal ◽  
P. Camacho ◽  
J. Manem ◽  
D. Hesnault ◽  
...  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Operating Conditions ◽  
Landfill Site ◽  
Order Kinetic ◽  
Methane Potential ◽  
Municipal Solid Waste Landfills ◽  
In Situ Decomposition ◽  
Solid Waste Landfills

The objective of this study was to develop a tool to predict the quantity of biogas produced by a municipal solid waste (MSW) landfill site to allow the energy it represents to be exploited. The model proposed is based on a first-order kinetic equation which describes the production of methane during in-situ decomposition of MSW. This equation was applied to a landfill site considering the MSW mass as a series of layers of waste of differing ages. The equation includes three parameters: MPo, the methane potential of fresh waste which is specific to MSW, d, the in-situ life duration of the waste which depends on the landfilling conditions and Ti, the filling rate, i.e. the rate at which waste is placed in the landfill site. This simple model, usable for all types of landfill and, by virtue of the parameters it uses, closely represents the site operating conditions. The approach was applied to the Villeparisis site and predicted a methane production rate of between 270 and 410 m3h−1, quite close to the measured value of 300 m3.h−1. In addition, the possibility of simulating variable landfill rates and waste life durations can be used to guide site management techniques to optimize the valorisation of the biogas and provide a global approach to the problem by incorporating leachate collection into the biogas exploitation calculations.

Treatment of leachate from municipal solid waste of Mostaganem district in Algeria: Decision support for advising a process treatment

2017 ◽  
Vol 36 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Z Bourechech ◽  
F Abdelmalek ◽  
MR Ghezzar ◽  
A Addou
Keyword(s):  
Municipal Solid Waste ◽  
Chemical Oxygen Demand ◽  
Solid Waste ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Fenton Process ◽  
Adsorption Processes ◽  
The One ◽  
Suitable Process

The aim of this work is to propose a plan for the choice of a suitable process for the treatment of a young leachate from municipal solid waste. Classical processes were applied: Fenton process, the coupling coagulation-Fenton process and the adsorption on powdered activated carbon (PAC). The study involves synthesised leachates from three types of wastes collected from sanitary landfill (SL): leachate of putrescible fraction (Lp), paper-cardboard (Lpc), sawdust (Ls) and the one of landfill (Lsl). The optimal operating conditions have been determined for the three processes: Fenton: [H2O2] = 6.8 g L-1 and [Fe2+] = 2.8 g L-1, coagulation: [Fe3+] = 0.3 g L-1 and adsorption: [PAC] = 60 g L-1. The three processes gave reduction rates of chemical oxygen demand ranging from 50% to 85% for Lp, 87% to 97% for Lpc and 61% to 87% for Ls. Whereas for Lsl, it was of 45%, 56% and 80% for the Fenton, coagulation-Fenton and adsorption processes, respectively. A modelling study was conducted to calculate the chemical oxygen demand of leachate produced during 25 years for different thicknesses of waste. This predicted value is used to advise for the process treatment to apply and to assess the environmental impacts in the long term.

On-line NIR monitoring during anaerobic treatment of municipal solid waste

2003 ◽  
Vol 48 (4) ◽  
pp. 9-13 ◽  
Author(s):  
M. Hansson ◽  
Å Nordberg ◽  
B. Mathisen
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Near Infrared ◽  
C:N Ratio ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Anaerobic Treatment ◽  
Operating Conditions ◽  
On Line ◽  
Process Disturbances

An anaerobic digester (8 l) was fed with the organic fraction of municipal solid waste and monitored intermittently for two years with on-line near-infrared (NIR) spectroscopy and traditional chemical parameters analysed off-line. The dynamics that occurred due to changes in substrate composition (changed C:N ratio) and changes in operating conditions (overloading) could be followed using principal component analysis of the obtained NIR-spectra. In addition, process disturbances such as failed stirring and increased foaming were readily detected by the NIR-spectra. Using PLS regression the propionate concentration could be predicted in the range 0.1-3.6 g/l, RMSEP 0.53 g/l with slope 0.74 and correlation coefficient 0.85. The response on changes in the digester fluid was reproducible and could be detected within 2.5 minutes, which can be considered as real-time monitoring.

scholarly journals Characterisation and composition identification of waste-derived fuels obtained from municipal solid waste using thermogravimetry: A review

2020 ◽  
Vol 38 (9) ◽  
pp. 942-965
Author(s):  
Spyridoula Gerassimidou ◽  
Costas A Velis ◽  
Paul T Williams ◽  
Dimitrios Komilis
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Evolved Gas Analysis ◽  
Complex Mixture ◽  
Compositional Analysis ◽  
Gas Analysis ◽  
Operating Conditions ◽  
Test Portion ◽  
Analytical Technique ◽  
Multiple Levels

Thermogravimetric analysis (TGA) is the most widespread thermal analytical technique applied to waste materials. By way of critical review, we establish a theoretical framework for the use of TGA under non-isothermal conditions for compositional analysis of waste-derived fuels from municipal solid waste (MSW) (solid recovered fuel (SRF), or refuse-derived fuel (RDF)). Thermal behaviour of SRF/RDF is described as a complex mixture of several components at multiple levels (including an assembly of prevalent waste items, materials, and chemical compounds); and, operating conditions applied to TGA experiments of SRF/RDF are summarised. SRF/RDF mainly contains cellulose, hemicellulose, lignin, polyethylene, polypropylene, and polyethylene terephthalate. Polyvinyl chloride is also used in simulated samples, for its high chlorine content. We discuss the main limitations for TGA-based compositional analysis of SRF/RDF, due to inherently heterogeneous composition of MSW at multiple levels, overlapping degradation areas, and potential interaction effects among waste components and cross-contamination. Optimal generic TGA settings are highlighted (inert atmosphere and low heating rate (⩽10°C), sufficient temperature range for material degradation (⩾750°C), and representative amount of test portion). There is high potential to develop TGA-based composition identification and wider quality assurance and control methods using advanced thermo-analytical techniques (e.g. TGA with evolved gas analysis), coupled with statistical data analytics.

scholarly journals Revisiting the Rist diagram for predicting operating conditions in blast furnaces with multiple injections

2021 ◽  
Vol 1 ◽  
pp. 141
Author(s):  
Manuel Bailera ◽  
Takao Nakagaki ◽  
Ryoma Kataoka
Keyword(s):  
Blast Furnace ◽  
Operating Conditions ◽  
Air Separation ◽  
Blast Furnaces ◽  
Geological Storage ◽  
Separation Unit ◽  
Pulverized Coal Injection ◽  
Air Separation Unit ◽  
Oxygen Blast ◽  
Power To Gas

Background: The Rist diagram is useful for predicting changes in blast furnaces when the operating conditions are modified. In this paper, we revisit this methodology to provide a general model with additions and corrections. The reason for this is to study a new concept proposal that combines oxygen blast furnaces with Power to Gas technology. The latter produces synthetic methane by using renewable electricity and CO2 to partly replace the fossil input in the blast furnace. Carbon is thus continuously recycled in a closed loop and geological storage is avoided. Methods: The new model is validated with three data sets corresponding to (1) an air-blown blast furnace without auxiliary injections, (2) an air-blown blast furnace with pulverized coal injection and (3) an oxygen blast furnace with top gas recycling and pulverized coal injection. The error is below 8% in all cases. Results: Assuming a 280 tHM/h oxygen blast furnace that produces 1154 kgCO2/tHM, we can reduce the CO2 emissions between 6.1% and 7.4% by coupling a 150 MW Power to Gas plant. This produces 21.8 kg/tHM of synthetic methane that replaces 22.8 kg/tHM of coke or 30.2 kg/tHM of coal. The gross energy penalization of the CO2 avoidance is 27.1 MJ/kgCO2 when coke is replaced and 22.4 MJ/kgCO2 when coal is replaced. Considering the energy content of the saved fossil fuel, and the electricity no longer consumed in the air separation unit thanks to the O2 coming from the electrolyzer, the net energy penalizations are 23.1 MJ/kgCO2 and 17.9 MJ/kgCO2, respectively. Discussion: The proposed integration has energy penalizations greater than conventional amine carbon capture (typically 3.7 – 4.8 MJ/kgCO2), but in return it could reduce the economic costs thanks to diminishing the coke/coal consumption, reducing the electricity consumption in the air separation unit, and eliminating the requirement of geological storage.

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