Iraqi Journal of Chemical and Petroleum Engineering

The corrosion of low carbon steel boiler tubes in demi water had been investigated. The purpose
of this investigation was to determine the change produced in corrosion behavior of the carbon
steel as a result of the specific presence of chloride and copper ions in the water under different
temperatures.
For low carbon steel experiments, the temperature was taken in three levels (125, 175, and
215°C) under about 27 bar pressure and 1500 rpm in autoclave. Using weight loss technique, the
corrosion rate ranges from (85 to 789 gmd) for low carbon steel boiler tubes

Used automobile oils were subjected to filtration to remove solid material and dehydration to
remove water, gasoline and light components by using vacuum distillation under moderate pressure,
and then the dehydrated waste oil is subjected to extraction by using liquid solvents. Two solvents,
namely n-butanol and n-hexane were used to extract base oil from automobile used oil, so that the
expensive base oil can be reused again.
The recovered base oil by using n-butanol solvent gives (88.67%) reduction in carbon residue,
(75.93%) reduction in ash content, (93.73%) oil recovery, (95%) solvent recovery and (100.62)
viscosity index, at (5:1) solvent to used oil ratio and (40 oC) extraction temperature, while using nhexane solvent gives (60.25%) reduction in carbon residue, (76.54%) reduction in ash content,
(89.06%) oil recovery, (94.78%) solvent recovery and (100.3) viscosity index, at (6:1) solvent to
used oil ratio and (50 oC) extraction temperature.

The present work aims to study the efficiency of using aluminum refuse, which is available locally
(after dissolving it in sodium hydroxide), with different coagulants like alum [Al2 (SO4)3.18H2O],
Ferric chloride FeCl3 and polyaluminum chloride (PACl) to improve the quality of water. The
results showed that using this coagulant in the flocculation process gave high results in the removal
of turbidity as well as improving the quality of water by precipitating a great deal of ions causing
hardness. From the experimental results of the Jar test, the optimum alum dosages are (25, 50 and
70 ppm), ferric chloride dosages are (15, 40 and 60 ppm) and polyaluminum chloride dosages were
(10, 35 and 55 ppm) for initial water turbidity (100, 500 and 1000 NTU) respectively. While, adding
sodium aluminate with the coagulants (Alum, FeCl3 and PACl), the optimum dose of 50 ppm was
enough for the reduction of turbidity and hardness of water.

Feasibility of biosorbent of England bamboo plant origin was tested for removal of priority
metal ions such as Cu and Zn from aqueous solutions in single metal state. Batch single metal state
experiments were performed to determine the effect of dosage (0.5, 1 and 1.5 g), pH (3, 4, 4.5, 5
and 6), mixing speed (90, 111, 131, 156 and 170 rpm), temperature (20, 25, 30 and 35 °C) and
metal ion concentration (10, 50, 70, 90 and 100 mg/L) on the ability of dried biomass to remove
metal from solutions which were investigated. Dried powder of bamboo removed (for single metal
state) about 74 % Cu and 69% Zn and maximum uptake of Cu and Zn was 7.39 mg/g and 6.96
mg/g respectively, from 100 mg/L of synthetic metal solution in 120 min. of contact time at pH 4.5
and 25°C with continuous stirring at 170 rpm. Experimental results have been analyzed using
Langmuir and Freundlich isotherms. Both equilibrium sorption isotherms were found to represent
well the measured sorption data, but Freundlich isotherm was better than Langmuir isotherm. The
effect of time was studied and the rate of removal of Cu (II) and Zn (II) ions from aqueous solution
by bamboo plant was found. The rates of sorption of copper and zinc were rapid initially within 5-
15 minutes and reached a maximum in about 60 minutes.

Experimental activity coefficients at infinite dilution are particularly useful for calculating the
parameters needed in an expression for the excess Gibbs energy. If reliable values of γ∞1 and γ∞2 are
available, either from direct experiment or from a correlation, it is possible to predict the composition
of the azeotrope and vapor-liquid equilibrium over the entire range of composition. These can be used
to evaluate two adjustable constants in any desired expression for G E. In this study MOSCED model
and SPACE model are two different methods were used to calculate γ∞1 and γ∞2

The production of power using the process of pressure–retarded osmosis (PRO) has been studied both
experimentally and theoretically for simulated sea water vs. river water and deionized water under two
cases: the first is for simulated real conditions of sea water and river water and second under low brine
solution concentration to examine the full profile of the power- pressure. The influence of
concentration polarization (CP) on water flux has been examined as well.