Nickel catalyst in coupled plasma-catalytic system for tar removal

Tar formation is a significant issue during biomass gasification. Catalytic removal of tars with the use of nickel catalyst allows to obtain high conversion rate but coke formation on catalysts surface lead to its deactivation. Toluene decomposition as a tar imitator was studied in gliding discharge plasma-catalytic system with the use of 5%, 10% and 15% by weight Ni and NiO catalyst on Al2O3 (α-Al2O3) and Peshiney (γ-Al2O3) carrier in gas composition similar to the gas after biomass pyrolysis. The optimal concentration of nickel was identified to be 10% by weight on Al2O3. It was stable in all studied initial toluene concentrations, discharge power while C7H8 conversion rate remained high – up to 82%. During the process, nickel catalysts were deactivated by sooth formation on the surface. On catalysts surface, toluene decomposition products were identified including benzyl alcohol and 3-hexen-2-one.

REFORMING OF ETHANOL IN PLASMA-CATALYTIC SYSTEM WITH DC AND AC ROTATING GLIDING DISCHARGE

The article presents the results of the investigation of the reforming of ethanol into synthesis gas using a plasmacatalytic system with either AC or DC wide-aperture rotating gliding discharge. Current and voltage oscillograms of the wide-aperture rotating gliding discharge were measured. The time-dependence of the instantaneous power of the discharge in the air was built. The photographs of the discharge in the airflow and discharge during the ethanol reforming were compared. The optical emission spectra of the plasmas of the torches of AC and DC wide-aperture rotating gliding discharges were studied. The rotational and vibrational temperatures of the plasma torch in the reaction chamber were determined. The results of the gas-chromatography of the synthesis gas produced during the plasm-catalytic reforming of ethanol using either AC or DC rotating gliding discharge are presented.

PLASMA-CATALYTIC SYSTEM WITH NARROW-APERTURE ROTATING GLIDING DISCHARGE

The article presents the results of the investigation of the rotating gliding discharge with the narrow aperture in the airflow. The photographs of the rotating gliding discharge with the narrow aperture were matched with its voltage oscillograms. Photographs were used to determine the maximum length of the discharge channel and its dependence on the airflow Gd into the discharge chamber. Voltage oscillograms were used to determine the difference between the maximum and minimum discharge voltage ΔU = Umax-Umin. The dependence of the electric field in the positive column on the airflow Gd into the discharge chamber was plotted. Optical emission spectra of the plasma of the rotating gliding discharge with a narrow aperture were captured and used to determine the distribution of the vibrational Tv and rotational Tr temperatures along the length of the plasma torch inside the reaction chamber.

Plasma Activated Synthesis of Macromolecular Compound

The paper is devoted to study of the plasma-activated synthesis of organic compounds with optically activity. Synthesis was carried out in plasma-liquid system with a rotating gliding discharge submerged in a liquid. The initial reagents of synthesis were ethanol, ammonia, and CO₂. The possibility of the influence of the electric field direction on the optical activity of the products of plasma-activated synthesis is shown.

Hybrid Plasma-Catalytic Reforming of Ethanol into Synthesis Gas: Experiment and Modeling

Understanding of the plasma-assisted reforming of hydrocarbons requires a combined application of the experimental studies of reforming systems and the kinetics modeling of reforming processes. Experiments were conducted on a system with a wide-aperture rotating gliding discharge with atmospheric air used as a plasma gas. Reforming parameters essential for the kinetics modelling of the reforming process were obtained. The influence of water addition method on the product composition of plasma-catalytic ethanol reforming was investigated.

Coupled Plasma-Catalytic System with Rang 19pr Catalyst for Conversion of Tar

A coupled plasma-catalytic system (CPCS) for the conversion of toluene was investigated and compared to the homogeneous system of gliding discharge plasma. Toluene was used as a model compound, which is present in tars. The study was carried out at atmospheric pressure, in a gas composition similar to the one obtained during pyrolysis of biomass. The effect of the initial toluene concentration, energy supplied to gliding discharge (GD) and the presence of a catalyst on the conversion of toluene was studied. Both the composition of outlet gas and its calorific value were monitored. Based on the obtained results it can be concluded that the conversion of toluene increases with the increase of gliding discharge power. The highest toluene conversion (89%) was received in the coupled plasma-catalytic system (catalyst: RANG-19PR) under the following conditions: CO (0.13 mol. fr.), CO2 (0.12 mol. fr.), H2 (0.25 mol. fr.), N2 (0.50 mol. fr.) and 4400 ppm of toluene with a gas flow rate of 1000 Nl/h. The composition of the outlet gas in the homogeneous system and in the CPCS changed in the range of a few percents. Toluene levels were reduced tenfold. Benzene, C3 and C4 hydrocarbons, as well as acetylene, ethylene and ethane, were detected in the outlet stream in trace amounts. Carbon deposits were present in the reactor. The products of methanation of carbon oxides were detected in the both studied systems. A mechanism of toluene decomposition in the CPCS was proposed. The application of the catalyst brought about an increase in the calorific value of the outlet gas. It was above the minimal level demanded by engines and turbines.