Minggong Chen

Hydrogen production by steam reforming for glycerol as a model oxygenate from bio-oil

Glycerol is a model whose ingredients are dominant in bio-oil, that is the reason why this thesis chooses glycerol as the model to pyrolyze biomass into oil. The thesis adopts coprecipitation method to produce a series of Ni-based catalysts, researches the rules and principles of restructuring glycerol into hydrogen in gasification reactor and explores the reaction conditions and reaction principles to restructure glycerol and to produce hydrogen. The result of this experiment shows that Ni-dolomite catalyst, in addition with oxide MgO or oxide CoO, greatly improves the activities of catalyst and effectively reduces the rate of carbon deposition. In order to study the restructuring reaction-temperature, ratio of water-carbon as well as the effect of feeding flow rate on the restructuring glycerol into hydrogen by steam catalysis, the thesis chooses Ni/MgO-CoO-dolomite as catalyst and the productivity of H2, CO, CH4, CO2 in reaction gas as research index. The ideal reaction condition is acquired as follow: reaction temperature is 650–700°C; S/C is 8–10 and feeding flow rate is 2.5–4ml/min.

Catalytic effects of several additives on co-pyrolysis of tobacco stalk and waste rubber tire powder

The components and yield of the oil obtained by co-pyrolysis of a mixture of tobacco stem and waste rubber tire powder were investigated. The results shows that 450°C is an optimal temperature in terms of liquid product yield when the reactants are mixtures of tobacco stem and waste rubber tire powder with a mass ratio of 1∶1. It is found that the liquid product from co-pyrolysis contains less water and oxygen element, and meanwhile, hydrocarbon content increases to some degree compared with that from pyrolysis of solo pyrolysis of tobacco stem, which means the oil from co-pyrolysis is improved. However, how to improve the liquid product quality further and how to control the hazardous element emissions via co-pyrolysis needs still further studies.

Non-thermal plasma combined with CuO/sepiolite clay catalyst removal NO

The modified sepiolite clay catalyst cleaned by nitric acid, impregnated copper nitrate, drying and then calcinations, combined with non-thermal plasma produced by dielectric barrier discharge reactor to remove NO. With XRD analyzed pattern of original and modified sepiolite, the Mg element and others were effectively removed from the original sepiolite by cleaning with nitric acid; the stable phase CuO was formed in the surface of catalyst after immersion and calcinations; the structure of sepiolite almost did not changed after modification so the sepiolite has a good ability to act as catalyst carrier. SEM micrograph of the sepiolite catalyst indicated the number of micro hole were improved and the surface area was increased by treatment, the active point of CuO was uniformly distributed in the surface without stack mess. The results show the acid concentration, cleaning time has an effect on NO removal ratio. Catalyst activity increased and then decreased with increasing of the acid cleaning time. The ratio increased with the increasing of input voltage. The modified sepiolite catalyst has a good ability to adsorb and store NO and take on Barrier Dielectric for Discharge. The order NO removal ratio is as follows: (plasma+ catalyst with acid cleaning, copper nitrate immersed and calcinations) > (catalyst with acid cleaning, copper nitrate immersed and calcinations) > (plasma+ sepiolite catalyst without acid cleaning, but copper nitrate immersed and calcinations) > (plasma+ original sepiolite) > only plasma. When the input voltage was 35kV, the nitric acid concentration of 1.5mol/L used to immerse original sepiolite for 48h, 8% CuO was loaded in the sepiolite surface and the catalyst was calcinated at 500°C for 5h, the maximum ratio value may reach 71%. The This research has been supported by the National Natural Science Foundation of China (No.21076002) investigation proved that the modified sepiolite catalyst combined with non-thermal plasma had a good ability to remove NO.

Gasification of Acetic Acid as a Model Oxygenate from Bio-Oil by Microwave Heating

Acetic acid was chosen as a model compound of fast pyrolysis bio-oil, A series of Ni-based catalyst were prepared for gasification of acetic acid in a fixed bed by microwave heating. The experimental results indicate that the additives of MgO and CoO to the Ni/Dolomite can improve the catalyst selectivity obviously, at the same time, Ni/Dolomite catalyst can reduce the carbon deposition rate efficiently. Here we have conducted the gasification of acetic acid with Ni/MgO- CoO-Dolomite and H2,CH4,CO,CO2 as indicator in a fixed bed by microwave heating for the purpose of obtaining some knowledge of its behavior under different conditions. The effects of the reactor temperature, feeding rate, molar ratio of H2O/C on yields of gas and composition of gaseous product have been investigated and the liquid product has been qualitatively analyzed. the optimum conditions is microwave temperature 750℃-900℃,H2O to carbon ratio 4-7 and feeding rate 2.5-3.2ml/min.

Treatment of cutting and emulsifying wastewater by non-thermal plasma

The technology of non-thermal plasma was used to treat cutting and emulsifying wastewater and investigate the effect of initial pH value of wastewater, several kinds of inorganic salt or not, velocity of airflow, electrode distance, input voltage, discharge time on wastewater treatment ratio. The experiment results show: the effect of wastewater purifying ratio increases with prolonging the plasma discharge time, the effect of wastewater purifying tends to steady after discharge time exceeds 120min; acidic conditions of wastewater is benefit to improve purifying ratio then basic condition. Putting a little of inorganic salt can increase the effect of wastewater purifying ratio, in this experiment, the effect of CaCl2 is better than Al2(SO4)3, FeSO4, NaCl. The distance between electrodes have more effects of wastewater treatment, the purifying ratio of gas phase discharge is better then liquid phase discharge and gas-liquid interface. Putting air into the wastewater can increase the effect of treatment, but when the velocity of airflow is too high the residence time will be short and then reduce the purifying ratio. The purifying ratio increases with the increasing of input voltage. In this experiment when the input voltage is 25kV, electrode distance 35mm, airflow 0.2L/min, CaCl2 1.6g/L, discharge time 30 min, the removal ratio of COD and turbidity could reach 90% and 92%, respectively.

The effect of catalyst sizes on discharge power in dielectric barrier discharge reactor

Dielectric Barrier Discharge (DBD) with catalyst can remove NOx effectively from diesel exhaust gas, the solid catalyst particles in the type of one section DBD reactor can play the role of barrier, lead to improve the discharge power effectively. The effect rule of the particle diameter which filled in the DBD reactor on the discharge power is studied by establishing mathematical model and testing in this paper. The results show that the discharge power first increase and decrease afterwards with the improving of material filler diameter, as well as the effect of particle diameter on the discharge power is more significant in pace with the input voltage rising. The gap enhances with particle diameter increases when the filler particle diameter is lager than the peak in the DBD reactor, under the same conditions, gap capacitance is less than solid particles capacitance, reducing the total capacitance decrease, so discharge power decreases with the particle diameter increases. When the filler particle diameter is less than the peak, the thickness of the equivalent capacitance of solid particles becomes smaller with the particle diameter decreases, susceptible to breakdown, the capacitance reducing, so discharge power falls with the particle diameter decreases. The discharge enhances with the input voltage increases, the effective area improving while the maximum effective discharge area is related to the particle diameter, so the effects of particle diameter on the discharge power is enhanced with the input voltage increases. The filler particle diameter has little effect on the total input power of the reactor because the total input energy is not only consumed for the system discharge, but also resulted heat the system. Theoretical model has the basically variation trend with experimental test results, the result provides the theoretical basis for selecting a suitable diameter of catalyst particles in catalytic reactions which assisted with DBD.