Laizhi Sun

High quality fuel gas from biomass pyrolysis with calcium oxide.

The removal of CO2 and tar in fuel gas produced by biomass thermal conversion has aroused more attention due to their adverse effects on the subsequent fuel gas application. High quality fuel gas production from sawdust pyrolysis with CaO was studied in this paper. The results of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments indicate that the mass ratio of CaO to sawdust (Ca/S) remarkably affects the behavior of sawdust pyrolysis. On the basis of Py-GC/MS results, one system of a moving bed pyrolyzer coupled with a fluid bed combustor has been developed to produce high quality fuel gas. The lower heating value (LHV) of the fuel gas was above 16MJ/Nm(3) and the content of tar was under 50mg/Nm(3), which is suitable for gas turbine application to generate electricity and heat. Therefore, this technology may be a promising route to achieve high quality fuel gas for biomass utilization.

Characterization of Rice Husk by Pyrolysis–Gas Chromatography–Mass Spectrometry

The analysis of products from rice husk under different decomposition temperatures was investigated by pyrolysis–gas chromatography–mass spectrometry. Compounds of molecular weight among 50–400 amu in the reaction products were identified. The products were characterized as unsaturated aliphatic hydrocarbons, carboxyolic acids, aromatics, phenols, and aldehydes/ketones. The results showed that pyrolysis temperature above 700°C accelerated the generation of unsaturated aliphatic hydrocarbons. The minimum concentrations of carboxylic acids and aldehydes/ketones appeared at 800 and 900°C, respectively, while the maximum levels of carboxylic acids, phenols, and aldehydes/ketones were obtained at 700°C. The lowest concentration of aromatics was also obtained at 700°C. These results are expected to serve as reference values for research and industrial production of biological oils.

A study of the in-situ CO 2 removal pyrolysis of Chinese herb residue for syngas production

The in-situ CO2 removal pyrolysis of Chinese herb residue was studied by thermodynamic equilibrium simulation and experimental methods. The effects of temperature, pressure, and CaO loading on the gas composition, heating value and yield were determined. The simulation results indicate that the heating value of product gas increases with the increase of Ca/H and pressure, and slightly decreases with the increase of temperature. The simulation results were verified by the experiments conducted with a micro fixed-bed reactor. Under the simulated reaction conditions including atmospheric pressure, reaction temperature of 700 °C and the Ca/H of 0.65, the CO2 in the product gas was effectively removed, resulting the syngas with a high heating value. The product gas was mainly composed of H2, CO, CO2 and CH4 with the contents of 47.52, 22.04, 9.01 and 14.02 respectively by experiment. And the lower heating value of the product gas reached 18.1 MJ/Nm3.

Study of the Ambient Vibration Energy Harvesting Based on Piezoelectric Effect

The resonance between piezoelectric vibrator and the vibration source is the key to maximize the ambient vibration energy harvesting by using piezoelectric generator. In this paper, the factors that influence the output power of a single piezoelectric vibrator are analyzed. The effect of geometry size (length, thickness, width of piezoelectric chip and thickness of metal shim) of a single cantilever piezoelectric vibrator to the output power is analyzed and simulated with the help of MATLAB (matrix laboratory). The curves that output power varies with geometry size are obtained when the displacement and load at the free end are constant. Then the paper points out multi-resonant frequency piezoelectric power generation, including cantilever multi-resonant frequency piezoelectric power generation and disc type multi-resonant frequency piezoelectric generation. Multi-resonant frequency of cantilever piezoelectric power generation can be realized by placing different quality mass at the free end, while disc type multi-resonant frequency piezoelectric generation can be realized through series and parallel connection of piezoelectric vibrator.