Simulation of biomass and municipal solid waste pellet gasification using Aspen Plus

Abstract The work deals with the simulation of biomass and municipal solid waste pellet gasification using Aspen Plus software. The effects of key parameters on the composition of the emitted gas are discussed, including gasification temperature, moisture content, and equivalence ratio. The sensitivity analysis was studied with the Aspen Plus Software, which includes FORTRAN modules. The simulation is validated using experimental results, which revealed that it was roughly correct. Using air as the gasification agent, the sensitivity analysis findings confirm higher temperatures promote syngas production with increased hydrogen and energy content. The simulation results demonstrated that CO2 concentration (3.95%) increases from 450°C to 600°C and then decreased drastically near 0.225kmol/hr. at 900°C. As the gasification temperature rises from 450°C to 900°C, the CO concentration rises and the H2: CO ratio falls. At 900°C, increasing the gasification temperature results in a product gas with more H2 (65%) and CO (12.43%), resulting in a higher calorific value, whereas the contents of CH4, CO2, and H2O followed an inverse correlation. CH4 decreased with temperature because of the formation of exothermic methane reactions. When the gasification process reaches 800°C, all components except CO2 become steady, and gasification reactions were achieved. The equivalence ratio (ER) ranged from 0.2 to 0.3. The gas produced by a gasifier is highly dependent on the ER value. The ER determines the gas quality, and it must be less than 1 to ensure that it gasifies the fuel rather than burnt. Moisture content was 10wt. %, this is an essential parameter for the optimum conditions during the gasification process. Moisture content determines the gas characteristics at the exit phase. The model predictions and calculated values are in good agreement.

Download Full-text

Autothermal biodrying of municipal solid waste with high moisture content

Chemical Papers ◽

10.2478/s11696-009-0118-3 ◽

2010 ◽

Vol 64 (2) ◽

Cited By ~ 10

Author(s):

Agnieszka Zawadzka ◽

Liliana Krzystek ◽

Stanisław Ledakowicz

Keyword(s):

Moisture Content ◽

Municipal Solid Waste ◽

Solid Waste ◽

Energy Content ◽

Plastic Material ◽

Initial Moisture Content ◽

Tubular Reactor ◽

Calorific Value ◽

High Energy ◽

Total Capacity

AbstractTo carry out autothermal drying processes during the composting of biomass, a horizontal tubular reactor was designed and tested. A biodrying tunnel of the total capacity of 240 dm3 was made of plastic material and insulated with polyurethane foam to prevent heat losses. Municipal solid waste and structural plant material were used as the input substrate. As a result of autothermal drying processes, moisture content decreased by 50 % of the initial moisture content of organic waste of about 800 g kg−1. In the tested cycles, high temperatures of biodried waste mass were achieved (54–56°C). An appropriate quantity of air was supplied to maintain a satisfactory level of temperature and moisture removal in the biodried mass and high energy content in the final product. The heat of combustion of dried waste and its calorific value were determined in a calorimeter. Examinations of pyrolysis and gasification of dried waste confirmed their usefulness as biofuel of satisfactory energy content.

Download Full-text

Influence of Aeration Modes on Aerobic Bio-Drying of Municipal Solid Waste (MSW)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1010-1012.934 ◽

2014 ◽

Vol 1010-1012 ◽

pp. 934-938

Author(s):

Hong Yu Zhang ◽

Jun Gu ◽

Gui Qin Wang ◽

Li Wei Hao ◽

Xue Qin Wu

Keyword(s):

Moisture Content ◽

Municipal Solid Waste ◽

Solid Waste ◽

Solid Waste Management ◽

Energy Content ◽

Municipal Solid Waste Management ◽

Drying Process ◽

Ventilation Mode ◽

First Choice ◽

Chinese Standard

The process of biodrying could be a good solution for municipal solid waste management, allowing the production of fuel with an interesting energy content. In this study, bio-drying the mixed municipal solid waste (with the size among 15-80 mm) with different aeration modes were conducted. During the experiment, temperature, oxygen content and moisture content were determined, and continuous measurements of H2S and CH4 were taken. The results indicated that the thermophilic phases of all treatments beside T1 were met the Chinese standard of >55°C for 5-7 days for sanitation. The aeration mode of T4 was in favor of reduced the H2S and CH4 emission during MSW bio-drying. Under the condition of this study, the bio-drying cycle should be determined for 18 days. Intermittent ventilation mode is more effective to reduce the moisture content in MSW bio-drying process. So the aeration mode of T4 (2.0L/min, 30min run/30 min stop) was the first choice during MSW bio-drying.

Download Full-text

An Investigation Into the Syngas Production From Municipal Solid Waste (MSW) Gasification Under Various Pressures and CO2 Concentration Atmospheres

17th Annual North American Waste-to-Energy Conference ◽

10.1115/nawtec17-2351 ◽

2009 ◽

Cited By ~ 6

Author(s):

Eilhann Kwon ◽

Kelly J. Westby ◽

Marco J. Castaldi

Keyword(s):

Thermal Degradation ◽

Municipal Solid Waste ◽

Solid Waste ◽

Co2 Concentration ◽

Operating Regime ◽

Inert Atmosphere ◽

Syngas Production ◽

Gasification Process ◽

Degradation Step ◽

Char Burnout

The Municipal Solid Waste (MSW) gasification process is a promising candidate for both MSW disposal and syngas production. The MSW gasification process has been characterized thermo-gravimetrically under various experimental atmospheres in order to understand syngas production and char burnout. This preliminary data shows that with any concentration of carbon dioxide in the atmosphere the residual char is reduced about 20% of the original mass (in an inert atmosphere) to about 5%, corresponding to a significant amount of carbon monoxide production (0.7% of CO was produced from a 20mg sample with 100ml/min of purge gas at 825°C). Two main steps of thermal degradation have been observed. The first thermal degradation step occurs at temperatures between 280∼350°C and consists mainly of the decomposition of the biomass component into light C1–3-hydrocarbons. The second thermal degradation step occurs between 380∼450°C and is mainly attributed to polymer components, such as plastics and rubber, in MSW. The polymer component in MSW gave off significant amount of benzene derivatives such as styrene. In order to identify the optimal operating regime for MSW gasification, a series of tests covering a range of temperatures (280∼700°C), pressures (30∼45 Bar), and atmospheres (100% N2, 0∼20%CO2+Bal. N2 with/without steam) have been done and the results are presented here.

Download Full-text

Modelling of syngas production from municipal solid waste (MSW) for methanol synthesis

Acta Chimica Slovaca ◽

10.1515/acs-2017-0019 ◽

2017 ◽

Vol 10 (2) ◽

pp. 107-114 ◽

Cited By ~ 6

Author(s):

Patrik Šuhaj ◽

Jakub Husár ◽

Juma Haydary

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Process Design ◽

Electricity Generation ◽

Liquid Fuel ◽

Process Optimisation ◽

Methanol Production ◽

Syngas Production ◽

Gasification Process ◽

Refuse Derived Fuel

AbstractApproximately 1 300 Gt of municipal solid waste (MSW) are produced worldwide every year. Most of it is disposed of in landfills, which is very hazardous for the environment. Up to 10 % of produced MSW are incinerated. However, incineration is not very effective and requires specific conditions for preventing emissions. Gasification and pyrolysis are more effective processes which can be used not only for heat and electricity generation but also for fuel and valuable chemicals production. MSW can be transformed into refuse-derived fuel (RDF) which has higher heat of combustion. Synthesis gas produced by RDF gasification can be utilised in methanol production. Methanol is a very lucrative chemical which can be used as renewable liquid fuel or as a reagent in organic syntheses. Gasifier design and process optimisation can be done using a reliable mathematical model. A good model can significantly decrease the number of experiments necessary for the gasification process design. In this work, equilibrium model for RDF gasification was designed in Aspen Plus environment and the flow of oxygen and steam as gasification agents were optimised to achieve the highest theoretical methanol yield. Impact of the recycle of unreacted steam and produced tar on the methanol yield was evaluated. The highest theoretical methanol yield (0.629 kgMEOH/kgRDF) was achieved when the steam and tar recycle were switched on, the ratio between oxygen and RDF feed was 0.423 kg/kg and that between the steam and RDF feed was 0.606 kg/kg. In this case, fresh steam represented only 12 % of the total steam fed to the reactor, the rest consisted of recycled steam. Optimal gasifier temperature was 900 °C.

Download Full-text

Simulation of Syngas Production from Municipal Solid Waste Gasification in a Bubbling Fluidized Bed Using Aspen Plus

Industrial & Engineering Chemistry Research ◽

10.1021/ie400026b ◽

2013 ◽

Vol 52 (42) ◽

pp. 14768-14775 ◽

Cited By ~ 52

Author(s):

Miaomiao Niu ◽

Yaji Huang ◽

Baosheng Jin ◽

Xinye Wang

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Fluidized Bed ◽

Aspen Plus ◽

Syngas Production ◽

Bubbling Fluidized Bed ◽

Waste Gasification

Download Full-text

Gasification of Municipal Solid Waste Using Tyre Char as Catalyst

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.797.102 ◽

2019 ◽

Vol 797 ◽

pp. 102-107

Author(s):

Mizan Qistina Saharuddin ◽

Sharifah Aishah Syed A. Kadir ◽

Rusmi Alias

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Energy Recovery ◽

Catalytic Performance ◽

Catalytic Gasification ◽

Tar Removal ◽

Principal Problem ◽

Syngas Production ◽

Gasification Process ◽

Waste Tyre

Gasification is raised as the most promising technologies of municipal solid waste (MSW) removal as well as energy recovery. The principal problem related with the gasification process is the high amount of tar released during the gasification process that causes environmental and operational problems. The purpose of this study is to investigate the performance of MSW gasification using tyre char as an alternative option for catalytic gasification to produce tar free clean gas. Catalytic performance of tyre char was compared with performance of MSW gasification alone without the tyre char in a bench scale downdraft reactor. The waste tyre char removed 80% of tars in syngas at 700 °C. Analysis of the syngas compositions indicated that concentration of H2and CO were significantly increased. Therefore, it was concluded that chars especially tyre char can be an effective and inexpensive catalyst for tar removal and syngas production of MSW gasification.

Download Full-text

Comparative Biodrying Performance of Municipal Solid Waste in the Reactor under Greenhouse and Non-greenhouse Conditions

Journal of Environmental Treatment Techniques ◽

10.47277/jett/9(1)217 ◽

2020 ◽

Vol 9 (1) ◽

pp. 211-217

Keyword(s):

Moisture Content ◽

Municipal Solid Waste ◽

Solid Waste ◽

Energy Content ◽

Pilot Scale ◽

Aeration Rate ◽

Operating Conditions ◽

Airflow Rate ◽

Greenhouse Condition ◽

Drying Time

The high moisture content of municipal solid waste yields a lower energy content of solid fuel that affects the thermal conversion efficiency. Biodrying is an alternative drying method using bio-heat generated by microbial metabolism to reduce the moisture content of municipal solid waste. This research was conducted in three pilot-scale biodrying reactors, two under greenhouse conditions compared with one conventional non-greenhouse condition. Two bunkers with greenhouse cladding were connected with aerators, and airflow rates were set at 0.4 and 0.6 m3/(kgwaste·day), respectively. Meanwhile, a passive aeration method was applied to the non-greenhouse bunker. This study aims to investigate the effect of the greenhouse condition on the biodrying process and assess the performance of the drying process through different operating conditions. The result shows that the greenhouse mainly affects the air temperature rise in the reactor. The aeration rate is positively correlated with weight reduction (r = 0.93). At 0.6 m3/(kgwaste·day) airflow rate, the treatment can reach a moisture content less than 30% on average within ten days, while at 0.4 m3/(kgwaste·day) airflow rate, it takes 15 days to reduce the moisture content to less than 30%. Biodrying under the greenhouse condition with active aeration potentially achieves desirable moisture content reduction and heating value increase more efficiently than the common biodrying. However, the airflow rate is a crucial factor in determining the suitable drying time in biodrying under the greenhouse condition.

Download Full-text

The Simulation of Sudanese Sugar Cane Bagasse Gasification Process Using ASPEN PLUS

Journal of Karary University for Engineering and Science ◽

10.54388/jkues.v1i1.8 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Mawa Mutaz ◽

Ibrahim H.Elamin ◽

Hamid M. Mustafa

Keyword(s):

Sugar Cane ◽

Aspen Plus ◽

Sugar Cane Bagasse ◽

Syngas Production ◽

Gasification Process ◽

Cold Gas Efficiency ◽

Biomass Ratio ◽

Gas Efficiency ◽

Alternative Processes ◽

Gasification Temperature

Bagasse has traditionally inefficiently burned in boilers for steam and electricity generation which still suffers from significant inefficiencies creating; therefore there is a need for alternative processes to be analyzed. Among the biomass utilization technologies, biomass gasification is an attractive solution for utilizing biomass effectively. In this study Aspen Plus simulation package V8 was used to develop a model for the gasification of Sudanese sugar cane bagasse in a fluidized bed reactor for syngas production. The developed model is based on Gibbs free energy minimization applying the non-stoichiometric equilibrium method for optimization of the gasifier performance. The objective is to study the effect of important operating parameters including gasification temperature, steam to biomass ratio (SBR) and air to biomass ratio (ABR), on syngas composition, low heating value (LHV) of syngas and cold gas efficiency (CGE). The optimal values of syngas composition, LHV and CGE were located at gasification temperature range from 750C to 950C, steam to biomass ratio around 0.5 to 0.8 and air to biomass ratio values equal to or below 0.4.

Download Full-text