It has been known for years that microbial surface active agents have a wide range of applications not only in oil spill environment but also in many industries. Their properties including: (i) changing surface active phenomena, such as lowering of surface and interfacial tensions, (ii) wetting and penetrating actions, (iii) spreading, (iv) hydrophylicity and hydrophobicity actions, (v) microbial growth enhancement, (vi) metal sequestration and (vii) anti-microbial action attract the biotechnologist’s attention to be substituted instead of synthetic ones. There are many advantages of biosurfacants in comparison with chemically synthesized counterparts like biodegradability, generally low toxicity, biocompatibility and digestibility, availability of cheap raw materials, acceptable production economics, use in environmental control, specificity and Effectiveness at extreme temperatures, pH and Salinity. Hydrophobic petroleum hydrocarbons require solubilization before degradation by microbial cells. Surfactants can increase the surface area of hydrophobic materials, such as oil spills in soil and water environment, thereby increasing their water solubility. Hence, the presence of surfactants would increase biodegradation of complex hydrocarbons like asphaltenes and resins. Increasing supply of heavy crude oils, bitumens, distillation vacuum residue in most of oil producing countries has increased the interest in transportation and conversion of the high-molecular weight fractions of these materials into refined fuels and petrochemicals and also the interest of conversion of heavy fraction of crude oil like vacuum distillation residue to more valuable components.

Dimethyl amino ethane azide (DMAZ) is a good replacement of hydrazine derivatives in aerospace industries. It is produced from the reaction between dimethyl amino ethyl chloride and aqueous sodium azide. DMAZ is formed in organic phase with a purity of at least 90%. High pure DMAZ is necessary for aerospace utilization. Thermal sensitivity of DMAZ leads the purification procedure to be performed at low temperatures. So, the Distillation at sub-atmospheric pressures is a good choice for this purpose. In this paper, effect of various parameters such as temperature and pressure on the distillation time and loss of material and final purity of DMAZ was studied in regular packed column, known as vigorous column, and optimized conditions were found.

The distillation unit is one of the main units in refining companies, and it serves as the mother unit in any refinery with any degree of complexity. The optimization of this unit can increase productivity. In this study, the vacuum distillation unit of a refinery was selected as the case study. The shares of different expenses of this unit were clarified using a novel material flow cost accounting (MFCA) method, the identification of the positive and negative products, and the identification of the actual values of the products. To this end, the vacuum distillation column was simulated by replacing Ahvaz’ s crude oil with different types of crude oils such as Mansouri, and Maroon and also by combining these crude oils types. The results showed that the difference between the quality of Ahvaz crude oil products and Maroon and their combination was less than 2%, so it can be an appropriate alternative to the main crude oil, without changing the column operating conditions. The influence of changing the column conditions was also studied which revealed the zero effect of the variations of the quality of Mansouri’ s crude oil products and its blend with Ahvaz crude oil. The feed temperature was changed 20 ° C while the input and bottom column pressure increased 7 and 5 mmHg, respectively. But API varied from approximately 3 to 7 in the products. Finally, two types of Mansouri’ s crude oil and a blend of Maroon and Ahvaz crude oil were introduced as the best alternatives to Ahvaz’ s crude oil.

A novel approach for the recovery of the proteins contained in the effluent formed during production of surimi-like material from mechanically recovered poultry meat was proposed, using an integrated membrane process comprising microfiltration, ultrafiltration and vacuum membrane distillation. Additionally, the possibility of using the integrated membrane process to achieve high-quality water for reuse was also investigated. Using cross-flow membrane techniques, it was found that the total recovery of soluble proteins as well as the average degree of concentration amounted to 84% and 9.3, respectively. Moreover, using this process, the total recovery of water was 70% and the percentage reduction in COD, TOEM and TSS in the permeate obtained using vacuum membrane distillation exceeded 99%. As a result, the water recovered by the integrated membrane process could be reused in the manufacture of surimi-like material from mechanically recovered poultry meat.

This investigation studied the separation of asphaltenes from the vacuum bottom, using industrial solvents such as normal pentane, hexane, and heptane. The central composite design (CCD) as a response surface methodology (RSM) method was applied to optimize the process. The weight percentage of asphaltene and the yield of de-asphalted oil (DAO) had been achieved at 0. 447 and 48%, respectively, under optimum economic conditions (normal hexane solvent, solvent to feed ratio of 9. 5 mL/g, and extraction temperature of 25 °C). The statistical study indicated that the response surface quadratic model for the mentioned parameters was significant and a perfect correlation between the statistical model and experimental data was found. Furthermore, according to an analysis of variance (ANOVA), the temperature of extraction and the quadratic interaction of the solvent to feed ratio parameter have shown a significant impact on the weight percentage of asphaltene. In general, the results suggest that the introduced approach is an efficient and economical technique to increase residual fluid catalytic cracking unit (RFCC) capacity and production of high-quality bitumen.

The Persian Gulf and its coastal areas are considered to be the largest source of crude oil in the world. On the other hand, the waste heat from the refining and petrochemical industries located around the Persian Gulf region can be used based on simple feed conditions for membrane distillation. Therefore, in order to improve the performance of this system in the desalination of Persian Gulf water and increase the flux of output, the mass and heat transfer model is simultaneously introduced into a membrane distillation system and validated with experimental data. The effect of different operating conditions such as feed temperature, vacuum pressure on the permeate side, feed concentration and heat transfer coefficient on the flux permeated have been investigated. Also, the effect of feed temperature on the temperature polarization phenomenon has been studied. The results showed that permeate flux increased with increasing feed temperature and heat transfer coefficient and decreased with increasing vacuum pressure and feed concentration. It was also found that the temperature increase would have an adverse effect on the phenomenon of temperature polarization.

Background: Chronic diabetes is substantially associated with circulatory disorders in lower limbs. Vacuum-Compression Therapy (VCT) has been commonly used in treatment of peripheral circulatory disorders. VCT is based on intermittent alteration of Positive- Negative pressure phases. The purpose of this study was to determine effects of VCT on diabetic subjects' peripheral blood flow.Methods: In this Before-After and case-series study, 18 type 2 diabetic subjects with diabetic neuropathy and/or peripheral vascular disease (PVD) completed the study. Subjects received 45 min of VCT for 10 sessions three times weekly. Blood flow (calf+foot) was measured via venous occlusion plethysmography.Results: Among Variables of "Arterial Inflow", "Venous Outflow", "Venous Capacity", "Postischemic Reactive Hyperemia" and "Peak Flow of Reactive Hyperemia", only "Venous Outflow" significantly improved after 10 sessions treatment via VCT (P<0.05).Conclusions: Arterial blood inflow, which was the most important determinant evaluated in this study, was not increased via VCT. Additional studies are required to investigate the effective VCT parameters and duration of each session and number of sessions, considering progressive and deteriorative natural history of diabetes.