A simple method for predicting the lower heating value of municipal solid waste in China based on wet physical composition

Integration of gasification with CO2 capture using CaO sorbent is proposed as an alternative treatment to convert municipal solid waste (MSW) into energy. Aspen Plus process simulator was employed to study the process. Two models were built to represent the non-sorbent and the sorbent-enabled MSW gasification. The model validation against available experimental data shows high accuracy of the simulation result. The effect of CO2 capture using CaO sorbent on the syngas composition and lower heating value (LHV) was observed by comparing the two models, and sensitivity analysis was performed on both models. Several process parameters affecting the syngas composition and LHV were investigated, including CaO/MSW ratio, temperature, equivalence ratio, and steam/MSW ratio. The addition of CaO sorbent for CO2 capture was found to successfully reduce the CO2 content in the syngas, increase the H2 composition, and improve the syngas LHV at the temperature below 750 oC. The maximum H2 composition of 56.67% was obtained from the sorbent-enabled gasification. It was found that increasing equivalence ratio leads to a higher H2 concentration and syngas LHV. Raising steam/MSW ratio also increases the H2 production, but also reduces the LHV of the syngas. Observation of the temperature effect found the highest H2 production at 650 oC for both non-sorbent and sorbent-enabled gasification.

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Combustion Study of Polyoxymethylene Dimethyl Ethers and Diesel Blend Fuels on an Optical Engine

Energies ◽

10.3390/en14154608 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4608

Author(s):

Jingjing He ◽

Hao Chen ◽

Xin Su ◽

Bin Xie ◽

Quanwei Li

Keyword(s):

Soot Formation ◽

Comprehensive Evaluation ◽

Chemical Properties ◽

Heating Value ◽

Optical Engine ◽

Leading Role ◽

Combustion Duration ◽

Polyoxymethylene Dimethyl Ethers ◽

Lower Heating Value ◽

Lower Heating

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.

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