Synergistic effect, kinetic and thermodynamics parameters analyses of co-gasification of municipal solid waste and bituminous coal with CO2

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.

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Investigation on Gaseous Product Distributions During Co-Pyrolysis of Platanus Wood and Different Rank Coals From Northwestern China in a Drop Tube Furnace

ASME 2015 Power Conference ◽

10.1115/power2015-49073 ◽

2015 ◽

Author(s):

Haiyu Meng ◽

Shuzhong Wang ◽

Lin Chen ◽

Wu Zhiqiang ◽

Jun Zhao

Keyword(s):

Synergistic Effect ◽

Municipal Solid Waste ◽

Solid Waste ◽

Gaseous Product ◽

Experimental Results ◽

Tube Furnace ◽

Thermochemical Conversion ◽

Drop Tube ◽

Drop Tube Furnace ◽

Product Distributions

Co-thermochemical conversion of municipal solid waste blends with coal has the advantage of diversifying energy resources and decreasing consumption of fossil fuels. As the initial and fundamental stage of co-thermochemical conversion, co-pyrolysis of municipal solid waste and coal has important influence on performance of the further co-combustion or co-gasification process. In this paper, gaseous product distributions during co-pyrolysis of platanus wood (wood waste from urban roadside trees platanus acerifolia) and two different rank coals (Shenmu bituminous and Pingzhuang lignite from northwestern China) were investigated through a semi-batch type drop tube furnace at different temperatures. The platanus wood/coal blends were fed into the furnace with five different mass ratios of 100/0, 70/30, 50/50, 30/70, and 0/100. The gaseous products (H2, CO, CO2, CH4 and light hydrocarbons) were continuously collected and then determined by gas chromatography. Experimental results indicated that the gaseous product distributions from pyrolysis of the platanus wood and coal blends were significantly affected by the temperature, the platanus wood/coal mass ratio and coal type. Compared the experimental results with the calculated values obtained from individual samples based on weighted average, some signs about positive or negative synergistic effect were observed on the formation of the major gas composition. The synergistic effect could probably be caused by the secondary reactions between volatiles and chars. In addition, the coal rank appeared to have different influence on the synergistic effect between platanus wood and coal during co-pyrolysis process.

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

Applied Sciences ◽

10.3390/app10061921 ◽

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.

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