Journal of the University of Chemical Technology and Metallurgy, XXXVII, Book4, 2002

CHEMICAL TECHNOLOGIES

 

ZnO - SORBENT EXPLOITATION PROPERTIES MODELING. II.TECHNICAL GRADE ZnO HYDROXICARBONIZATION - ASPECTS OF TECHNOLOGY
Tz. Velinova, L. Angelov, D. Shishkov

THE INFLUENCE OF PROCESSING PARAMETERS ON THE PROPERTIES AND COMPATIBILITY FROM LDPE/PP AND HDPE/PP BLENDS
Iv. Dimitrova

UNIFORM DYEING OF WOOL FIBRES AND REPRODUCTION OF COLOR
V. Lukanova, V. Gantchev

THE EFFECTS OF MICROWAVE IRRADIATIONS ON NATURAL SILK
A. K.Haghi, M. Mahfoozi, K. Mohammadi

TECHNOLOGY FOR BUTYL ACETATE PRODUCTION BY REACTIVE DISTILLATION
Zh. Balgaranova, L. Philipov

CALCULATION OF THE TEMPERATURE FLAMMABILITY LIMITS OF INDIVIDUAL HYDROCARBONS AND DISTILLATE OIL FRACTIONS I. TRANSFORMATION OF THE WILSON EQUATION
Z. Zdravchev, J. Balgaranova, M. Hristova, Ek. Tcholakova

 

ZnO - SORBENT EXPLOITATION PROPERTIES MODELLING.
II.TECHNICAL GRADE ZnO HYDROXICARBONIZATION - ASPECTS OF TECHNOLOGY.
Tz. Velinova, L. Angelov, D. Shishkov

        The positive results from the laboratory studies of ZnO - technical grade hydroxicarbonization as a method to produce ZnO-sorbent [1] show the expedience to continue experiments on a large scale. It is possible in this way not only to confirm the laboratory research conclusions but also to give detailed description of the process technology considering its industrial application. Modelling as intermediate or final stage is obligatory a component of almost all catalysts and sorbents technological production processes. Its inclusion in the studies will specify the possibilities for combination or compromise of the structural parameters (specific surface and porosity) and sorbent mechanical properties-strength.
Keywords: sorbent, hydroxicarbonization, micronization, technology, sulphur consumption.

THE INFLUENCE OF PROCESSING PARAMETERS ON THE PROPERTIES AND COMPATIBILITY FROM LDPE/PP AND HDPE/PP BLENDS
Iv. Dimitrova

 

 

It is well known, that polyethylene and polypropylene are thermodynamic incompatibile. The aim of this investigation is to improve the characteristics of blends of both semicrystalline polymers by means of optimization of mixing conditions.
Two types of polyethylene - low density polyethylene (LDPE) and high density polyethylene (HDPE) are blended with polypropylene (PP) by a single screw mixing extruder at different conditions (different proportions of polymers in blends and processing parameters - temperature and shear rate).
The received rheological data, changing of density and physical-mechanical properties of the blends studied here, show that the processing parameters considerably influence and reflect on the properties of the polymer blends.
Keywords: polymer blends, reactive extrusion, compatibility.

 

UNIFORM DYEING OF WOOL FIBRES AND REPRODUCTION OF COLOR
V. Lukanova, V. Gantchev

 

University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria E-mail: vkg@uctm.edu

Received 16 August 2002 Accepted 11 November 2002

 

The color system "DATACOLOR" gives unlimited possibilities for color sampling and running control, of the obtained during dyeing colorings' level of reproduction. This work examines research for obtaining of reseda green color on wool tops of 70-th and 60-th grade with "Lanaset" dyes in the presence of leveling additions on different chemical bases. The results show very good reproduction of the colorings compared to the standard, regarding color difference as well as depth and shade of color. It is determined that the use of leveling agents with fibre affinity results in better uniformity. The colorings obtained possess high fastness to washing, perspiration and rubbing with all examined products.
Keywords: wool, dyes "Lanaset", color system "DATACOLOR", leveling agents.

 

THE EFFECTS OF MICROWAVE IRRADIATIONS ON NATURAL SILK
A. Haghi, M. Mahfoozi, K. Mohammadi

 

The microwave and convective drying of an industrially prepared bundle of natural silk yarn has been experimentally investigated on a laboratory scale. The experiments were performed at different levels of heating temperature. The results obtained from the two drying techniques show less damage to the silk yarn by microwave radiation and a strong relationship between applied microwave power and drying time of natural silk samples.
Keywords : natural silk , convective drying , microwave drying , scanning electron microscopy.

TECHNOLOGY FOR BUTYL ACETATE PRODUCTION BY REACTIVE DISTILLATION
Zh. Balgaranova, L. Philipov

 

A non-waste technology for butyl acetate production of 97,5% purity was developed. The flow diagramme includes a distillation column, which substitutes reactors in series working in counter current. According to the method two processes occur simultaneously: a chemical reaction and a separation by distillation of the reaction products and non-reacted raw materials. Thus, a high rate of conversion is achieved. The optimal parameters of the stage column and of the process are determined by simulation.
Keywords: technology , butyl acetate, reactive distillation.

 

CALCULATION OF THE TEMPERATURE FLAMMABILITY LIMITS OF INDIVIDUAL HYDROCARBONS AND DISTILLATE OIL FRACTIONS
I. TRANSFORMATION OF THE WILSON EQUATION
Z. Zdravchev, J. Balgaranova, M. Hristova, Ek. Tcholakova

 

 

Analytical relationships are derived for the calculation of the temperature flammability limits of individual hydrocarbons present in distillate oil fractions. Aimed to this, Wilson's equation, which expresses the analytical dependence of the vapor pressure on the temperature, is transformed. Using the suggested equations, the upper temperature flammability limit is determined with sufficient practical accuracy, while for the lower temperature flammability limit greater deviations are observed when compared with the experimental data, existing in the literature.
Keywords: temperature flammability limits, fire hazard parameters, individual hydrocarbons from distillate oil fractions.