Gao Jin-sheng

Catalytic oxidation and kinetics of oxidation of coal-derived pyrite by electrolysis

Abstract The catalytic oxidation of coal-derived pyrite (CDP) into SO 4 2− and Fe 3+ and kinetics of oxidation of coal-derived pyrite by electrolysis were studied in a batch reactor. In this paper, the influence of electrolysis conditions on the pyrite conversion rate, such as particle size, electrolysis potential, reaction time, etc. was reported. It is obvious that the rate of conversion of pyrite ( C r ) increases with the increase of the electrolysis potential, reaction time, temperature, acidity and the concentration of catalyst (MnSO 4 ), but decreases with the increase of concentration of pyrite. The experimental data show that the reaction is marching with shrinking core model. The reaction-controlling step was found to be the reaction between Mn 3+ and pyrite. The active energy for oxidation of CDP into SO 4 2− and Fe 3+ by electrolysis is 29.6 kJ/mol.

Investigations on chemical compositions and fuel characteristics of biomass tar

Two kinds of biomass tars were obtained during the carbonization processes of corn straws (SL) and wood ships (FS) in the temperature range of 500–600 °C and 600–700 °C, respectively, and their physicochemical properties and chemical compositions were mainly investigated. The results showed that both of tars exhibited high volatile contents (55.45% and 76.44%), high carbon contents (48.42% and 52.36%, low sulfur contents (1.30% and 0.06%) and nitrogen contents (0.33% and 0.02%), and their heating value were both above 20.0MJ/Kg, which were favorable for being used as liquid fuel. Moreover, both of the tars were abundant in phenols, the content of phenols was 44.08% in SL and was up to 80.01% in FS. The main PAHs detected from SL were di-to tricyclic PAHs, including naphthalene and its derivatives, anthracene and pyrene, and the PAHs detected from FS were mainly included alkyl naphthalene. In addition, there were a large amount of alkanes (17.15%) in SL and a small amount of alkenes in two kinds of tars. These results obtained in this study could provide essential and useful information for the successful application of biomass tar, which also have an important influence on the efficiency of biomass energy.

The transformation and the hydrogenation activity of iron oxide under various reaction conditions in coal liquefaction

Abstract57Fe Mössbauer spectroscopy was used to investigate the evolution of iron oxide catalysts in coal liquefaction process. Their catalytic activities under various reaction conditions are disscussed.

DEVELOPMENT OF A NEW TYPE OF LOW-TEMPERATURE PATTERN WAX

The effects of several important components on casting waxes, such as low-melting point petroleum waxes, high-melting point waxes, stearic acid and additive 201 were investigated. A new type of LPW low-temperature pattern wax was developed by method of cooling curve. The experimental results showed that stearic acid and No. 56 petroleum wax could lower the casting temperature. No. 80 microcrystalline wax, No. 85 microcrystalline wax and additive 201 all could make the pattern wax crystal construction finer, although additive 201 was more effective than the microcrystalline waxes. The application tests showed that LPM pattern waxes were higher quality pattern waxes such as better gloss, higher rigidity and higher intensity than the original common low casting temperature pattern waxes.

DEVELOPMENT OF OXIDIZED POLYETHYLENE WAXES

ABSTRACT A method of preparation of oxidized polyethylene waxes, which have many applications such as in plastics, rubber, leather, paper, inks and textile, etc. was developed. The experiments of polyethylene waxes oxidization were carried out in a pilot plant. The reactor was a 0.27 m diameter and 3 m high column reactor with a conical distribution plate. The experimental results showed that the optimal conditions for preparation of the Oxidized Polyethylene Waxes were: catalyst KMnO4, reaction temperature 141—148°C, reaction time 3-7 h, air velocity 4—8 m/s. The oxidized polyethylene waxes with acid number of above 30 mgKOH/g could be obtained with this method.

A new activity phase in Hongqi brown coal liquefaction

The higher coal conversion yield is associated with the greater γ-Fe/Fe1−xS ratio in Hongqi brown coal liquefaction. The γ-Fe species possesses higher catalytic activity than Fe1−xS. Formation of γ-Fe species during liquefaction is related with the dispersity of iron in the coal.