Lab of Non-equilibrium Energy Conversion
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Ultimate Combustion

1. Supercritical Combustion Experiments

Supercritical combustion has tremendous potential in engines and gas turbines and due to its high combustion efficiency and ultra-lean flammability. However, supercritical combustion chemistry is very challenging due to the failure of gas-phase chemistry theory. We have built the first supercritical-pressure jet-stirred reactor (SP-JSR) for reaction kinetics study up to 200 atm. It is noted that this is the first ultra-high pressure JSR in the world. Our reactor design has won the Karl H. Walther Award from American scientific glassblowers society.

2. Supercritical Flow Computation

The Virial method describing real-fluid EoS, thermodynamic properties, and chemical potentials calculations is developed and applied for combustion modelling for various fuels in this work. The Virial method is constructed with deeper-level physical insights and higher accuracy comparing with empirical methods. The complete Virial method applicable to simulations of various fuels has been incorporated into Cantera program.

3. Supercritical Combustion Theory

We developed supercritical combustion models of H2, CH4, CH4O, C3H8, DME, C4H10 at 100 atm by using SP-JSR coupled with advanced diagnostics and real-fluid combustion simulations. Special attentions have been paid to supercritical low temperature chemistry and special NTC behavior. It is a collaborative work between PKU, Princeton University, and Argonne National Lab.

4. Sensitized Combustion Chemistry

The reaction mechanism of the following fuel was studied by means of electron impact flight mass spectrometry, laser absorption spectroscopy, Faraday rotation spectroscopy and Schlieren imaging.
The non-equilibrium fast thermal decomposition of formaldehyde (HCO) radical under high pressure was experimentally demonstrated by using a high pressure spherical combustion bomb, and the kinetic mechanism of the high pressure reaction between formaldehyde and 1, 3-butadiene was developed/updated.

The sensitization of NOx and ozone to low temperature chemistry of fuel was studied. The Princeton ozone reaction mechanism (HP-O3 MECH), NOx reaction mechanism, ozonedimethyl ether coupling mechanism and n-pentane NOx coupling mechanism were developed.

Quantification of H2O、CH4、C2H2、CH2Oby using QCL


Plasma Assisted Synthesis

1. Chemical Synthesis

We use non-thermal plasma technology to assist important chemical synthesis, such as ammonia, bio-methane, bio-methanol, etc., and further reduce CO2 emission and enhance energy sustainability. We studied the plasma catalyzed synthesis of NH3, and firstly identified and measured the concentration of the radical NNH and N2H2 by using in-situ molecular-beam mass spectrometry. This work was published in ACS Energy Letters as the front cover.

2. Experiments and Kinetic Modeling

We developed pulsed heating/quenching technology for enabling ammonia synthesis under atmospheric conditions, and predicted its potential application both in experiments and kinetic modeling. This work has been recently published in Nature as the front cover.

  • Programmable Heating and Quenching for Efficient Thermochemical Synthesis
    Qi Dong, Yonggang Yao, Sichao Cheng, Konstantinos Alexopoulos, Jinlong Gao, Sanjana Srinivas, Yifan Wang, Yong Pei, Chaolun Zheng, Alexandra H. Brozena, Xizheng Wang, Jiaqi Dai, Hao Zhao, Weiqing Zheng, Hilal Ezgi Toraman, Zhiwei Lin, Bao Yang, Yiguang Ju, Dionisios G. Vlachos, Dongxia Liu, Liangbing Hu*.
    Nature, 605 (2022) 470-476.

Lithium Battery Fire Safety

1. The Kinetic Chemistry of Battery

In lithium batteries, thermal runaway occurs at abuse conditions due to the interaction between cathode material and electrolyte, however, the kinetic chemistry of battery fire is still unknown. We first used ozone to mimic the oxidizing environment in Li-ion battery by providing active atomic oxygen. This study provides insights of the chemically sensitized gas-phase low temperature chemistry of electrolyte components and its degradation at 400-500 K.

2. In-situ Diagnostics of Key Parameters

In-situ monitoring of key characteristic parameters in electrolyte under strong electromagnetic interference is very important. We proposed an all-fiber probe and realized the in-situ diagnostics of key parameters in lithium batteries such as temperature, stress, and chemical composition in high accuracy.