تکتم شنوایی زارع

Disposal of storage tanks’ sludges due to the high concentration of hydrocarbon involved in them and environmental hazards are a major concerns in oil depots. In this study, reducing concentration of hydrocarbon in petroleum sludge by applying a low cost absorption was investigated. For this purpose, natural zeolite of Semnan zone was applied. In the first stage, modification of the zeolite surface was performed by different acids and the modified zeolites efficiencies were studied. According to obtained results, modification of zeolite surface improves hydrocarbon adsorption, so that HCl-modified zeolite provides maximum adsorption. In the second stage, the influence of physical and chemical parameters on the process was studied using Taguchi methods at two levels. The results show that contact time, the amount of adsorption and temperature are effective on the adsorption process. In the last stage, adsorption isotherm of process was examined, and it was found that the hydrocarbon adsorption on the modified zeolite follows the Temkin isotherm. Finally, the results of this study show that hydrocarbon concentration of sludge can be reduced to 83% using just 0.28 gr of low cost zeolite per 1 gr of sludge.

After the onset of the industrial revolution, the concentrations of greenhouse gases in the atmosphere increased rapidly. Global warming is caused by the emission of greenhouse gases. Carbon dioxide emissions are the most important cause of global warming. Now, there are several methods to remove carbon dioxide from gas streams. One of the proposed methods is the use of zeolites as the adsorbent which can separate CO2 using molecular sieve method. In this study, CO2 removal from Sabzevar Cement plant flue gas by Sabzevar zeolite was investigated.For this purpose, a laboratory - scale column was made and the effect of three factors including the size of zeolite, height-to-diameter ratio of the column (L/D), and gas inlet pressure were investigated in three levels using Taguchi method. ANOVA results showed that in the range of variables, the size of zeolite is the most important factor on the adsorption process. Also, L/D factor had a significant effect on the adsorption process. Under the obtained optimum conditions that involved the size of zeolite 2-2.36 mm, L/D 10.8,gas inlet pressure 90-98 kPa, about 80% of CO2 was removed from the flue-gas after 10 minutes and more than 60% of it was also removed after one hour by the zeolite column.