Muhanned A. Hararah

Pyrolysis of poly(vinyl chloride) and-electric arc furnacedust mixtures.

An investigation into the pyrolysis kinetics of PVC mixed with electric arc furnace dust (EAFD) was performed. Mixtures of both materials with varying PVC ratios (1:1, 1:2, 1:3) were prepared and pyrolyzed in a nitrogen atmosphere under dynamic heating conditions at different heating rates (5, 10, 30 and 50 °C/min). The pyrolysis process proceeded through two main decomposition steps; the first step involved the release of HCl which reacted with the metal oxides present in the dust, subsequently forming metal chlorides and water vapor. Benzene was also found to release as detected by TGA-MS. The remaining hydrocarbons in the polymer backbone decomposed further in the second step releasing further volatile hydrocarbons. Different models were used to fit the kinetic data namely the integral, the Van Krevelen, and Coats and Red fern methods. The presence of EAFD during PVC decomposition resulted in a considerable decrease in the activation energy of the reaction occurring during the first decomposition region. Furthermore, iron oxides were retained in the pyrolysis residue, whilst other valuable metals, including Zn and Pb, were converted to chlorides that are recoverable by leaching in water. It is believed that EAFD can be utilized as an active catalyst to produce energy gases such as propyneas evident from the TGA-MS.

Zinc adsorption–desorption isotherms: possible effects on the calcareous vertisol soils from Jordan

Calcareous vertisol soil is the dominant agricultural soil type and covers over 80% of the agricultural cultivated land in Jordan. This type of soil is characterized by its high pH and CaCO3 content, which made the heavy metals including Zn to be oxidized and adsorbed onto soil. Therefore, this type of soil is regarded as potentially Zn deficient. The effect of Zn initial concentration and average rainfall on the Zn adsorption and desorption from three types of calcareous vertisol soils has been examined. The amount of Zn adsorbed and desorbed at equilibrium increased with increasing Zn initial concentration for each of the three investigated soils. However, the percentage of adsorption and desorption decreased as the initial concentration of Zn ions increased. Moreover, results showed that rainfall has no influence on the behavior of Zn in the calcareous vertisol soils. Freundlich and Redlich-Peterson models provide the best representation of the experimental data, followed by the Langmuir model.

Viscosity correlations for jojoba oil blends with biodiesel and petroleum diesel

ABSTRACT In this study, the effect of temperature and mixture composition on viscosity of Jojoba oil-Biodiesel (JO-BD) and Jojoba oil-Diesel (JO-PD) blends are investigated. Moreover, the relationship between the viscosity and the specific gravity of the blends is studied. Experimental viscosity data for the temperature range between 20°C and 80°C are used. The results show that the viscosity–temperature dependency can be well correlated by Vogel model for the viscosity–temperature relation. Also, a method that could estimate the blends viscosity from the specific gravity data is established.

A preliminary study on the hydrogen reduction of jordanian iron ore

Abstract Jordanian iron ore samples, obtained from Warda area, were reduced using hydrogen gas and preliminary kinetic observations and results were obtained. Samples of iron ore were carefully sized, weighed and reduced using flowing hydrogen in a tubular furnace. Constant temperature experiments were conducted to examine the effect of particle size (180 to 710 μm), temperature (400 to 600°C) and gas flow rate (1 to 3 L min–1 at STP) on the percentage of reduction with time. It was found that the reduction rate increased with decreasing particle size, increasing gas flow rate, and increasing temperature. In general, the course of ore reduction was observed to follow three distinct stages; an initial stage of increasing percentage of reduction at an increasing rate, followed by a stage of decreasing rate, and a final stage with constant percentage of reduction. The initial stage was successfully modelled using the shrinking core model with the chemical reaction step controls, probably combined by gas diffusion. The observed activation energy of reduction for this period was 29 kJ mol–1.