NAPHTHA REMOVAL FROM PETROLEUM INDUSTRIAL EFFLUENT

Transcription

1 International Journal of Civil Engineering and Technology (IJCIET) Volume 6, Issue 9, Sep 2015, pp , Article ID: IJCIET_06_09_013 Available online at ISSN Print: and ISSN Online: IAEME Publication NAPHTHA REMOVAL FROM PETROLEUM INDUSTRIAL EFFLUENT Sherif A. Moustafa Assistant Professor of Public Work Engineering, Construction and Building Department, Faculty of Engineering, October 6th.University, EGYPT, Mohamed H. Al Awady Water Pollution Research Department, National Research Centre, Dokki, Cairo, Egypt M. A. Ashmawy Assistant Professor of Sanitation and environmental Department faculty of engineering Helwan University ABSTRACT The Purpose of this research is treat the industrial wastewater flow generated from El Nasr Petroleum Company to the accepted quality before discharging it into Suez Gulf. A series of bench scale experiments, were conducted in order to determine the best treatment process for such kind of industrial flow. This research succeeded to remove the phenolic compounds (naphtha) from the industrial effluent to the level stated in Law 4/1994. The optimum doses of both Fe2+ and H2O2 were determined using jar test to remove color, odor and COD constituents from the industrial effluent. The experimental results indicated that the optimum doses of 0.8 and 20 ml/l for Fe2+ and H2O2 respectively reduced COD concentration from 8200 to 500 mg/l in 30 minutes reaction time Key words: Petroleum Refinery and Petrochemical Waste; Electrolysis, Naphtha Removal Cite this Article: Sherif A. Moustafa, Mohamed H. Al Awady and M.A.Ashmawy. Naphtha Removal from Petroleum Industrial Effluent. International Journal of Civil Engineering and Technology, 6(9), 2015, pp INTRODUCTION Large amounts of water are used in a petroleum refinery and, consequently, significant volumes of wastewater are generated ( times the volume of processed oil) (Fica-Piras 2000). Petroleum refinery wastewater and its major editor@iaeme.com

2 Sherif A. Moustafa, Mohamed H. Al Awady and M.A.Ashmawy components such as phenols and Benzene, Toluene, ethylbenzene and Xylene (BTEX) and Naphtha has been studied to investigate the treatment efficiency by using aerobic, anaerobic and anoxic or a combinations of two or more biological conditions (1, 2,3,6.) El-Nasr Petroleum Company is one of two refineries located at Suez governorate, Egypt. The refinery is Egypt's largest with a capacity of 146,300 barrels per day (bpd). It processes more than 30 percent of the petroleum produced in Egypt and comprises of three crude distillation units, an accompanying asphalt production unit and a power generation plant. The company is discharging 16,800 m3/day of treated industrial wastewater mixed with 216,000 m3/day cooling water with total wastewater flow of 233,000 m3/day into Suez Gulf. The quality of effluent from El Nasr Company is not complying with Egyptian Environmental regulation in Egypt. El Nasr Petroleum Company is specialized crude distillation and asphalt. The industrial effluent of the company is discharged after passes through the existing treatment units into Suez Gulf. The effluent does not comply with the parameters stated in law No 4/1994 regarding the discharge into Sea. Therefore, the NPC requested to study this situation and modify / upgrade the existing treatment process to produce effluent complying with the parameters stated in law 4/1994. The existing treatment process consists of API oil separator to remove oil and grease. The total industrial wastewater is passed to Skim Basin where the 9000 m3 per hour cooling water is thoroughly mixed with the industrial wastewater coming from Naphtha section. Naphtha represents the main source of organic pollutants, with the maximum phenolic concentration, high alkalinity and chemical oxygen demand which exceeding the trigger levels in Law 4/1994 for discharging the water onto the sea shore. Samples were collected from Naphtha department outlet, effluent water from cooling process, influent waste to the API separator, effluent waste from API separator and final wastewater discharged onto Suez Gulf. Table No. 1 presents the characteristics of the industrial wastewater effluent from Naphtha department in the El Nasr Petroleum Company. Table 1 Characteristics of Industrial Wastewater flow from Naphtha Department Parameters Unit Value Maximum Limits of Parameters in Law 4/1994 Status ph Not Comply Chemical Oxygen Demand mg/l Not Comply Biological Oxygen Demand mg/l Not Comply Total Suspended Solids mg/l Not Comply Total Dissolved Solids mg/l Phosphate mg/l Comply Chlorides mg/l Not Comply Phenol mg/l Not Comply Total Kjeldahl Nitrogen mg/l Not Comply editor@iaeme.com

3 Naphtha Removal From Petroleum Industrial Effluent 2. MATERIALS AND METHODS Jar test was applied to the collected samples in order to determine the optimum doses of Fe 2+ and H 2 O 2, the optimum ph and reaction time to achieve maximum color, odor and COD removal efficiencies. The effect of different variables was studied by changing each in turn while keeping the other constant Analytical Measurements The materials used in the experiments were Fe 2 SO 4 7H 2 O solution and lime slurry and H 2 O 2 solution of (30%) (H 2 SO 4 30%) and [Ca (OH) 2 ] of 50% were prepared daily. All experiments were carried out in the jar test. Mixing speed of the apparatus was adjustable between 0 and 250 rpm. The ph-measurement was carried out using a phmeter. The measured parameters of wastewater during the experiments were Chemical Oxygen Demand (mg/l), Total Suspended Solids (TSS, mg/l), total Kjeldahl Nitrogen, Nitrite, Nitrate, Ammonia, ph and Oil & Grease. All parameters have been measured according to procedures given in the American Standard Methods, APHA (2008). The Naphtha industrial wastewater samples were obtained from the effluent from the Naphtha Department. The experiments were carried out at the laboratory of water pollution in NRC. 3. RESULTS AND DISCUSSION The optimal reaction conditions determined by following up the removal of COD and phenol, respectively. The effect of Fenton's reagent dosages on Fenton oxidation are summarized as follows: 3.1. Optimum ph The experiments were carried out using Jar tests to determine the optimum ph versus removal of both COD and Phenol. It is found that the optimum ph value to achieve the maximum removal of both COD and Phenol ranges from 9.5 to Optimum Detention Time Figure 1 COD Removal versus Detention Time editor@iaeme.com

4 Sherif A. Moustafa, Mohamed H. Al Awady and M.A.Ashmawy Figure 2 Phenol Removal versus Detention Time Figures 1 and 2 show that the optimum detention time for removal of both COD and Phenol is 30 minutes. It is found that 10 minutes detention time can achieve removal efficiency of COD and Phenol reaches up to 95% but in order to achieve the limits stated in law 4/1994, the detention time shall be increased to be 30 minutes Hydrogen Perxide (30%) Dose Figure 3 COD Removal versus Hydrogen Perxide (30%) Dose Figures 3 and 4 show that the optimum dose of hydrogen peroxide (30%) can reduce the concentration of COD and phenol to the limits stated in law 4/1994 at dose equal 65 ml/l editor@iaeme.com

5 Naphtha Removal From Petroleum Industrial Effluent Figure 4 Phenol Removal versus Hydrogen Perxide (30%) Dose 3.4. Optimum Dose of Fe2+ versus COD Figure 5 COD Removal versus Fe 2+ Dose Figure 6 Phenol Removal versus Fe 2+ Dose editor@iaeme.com

6 Sherif A. Moustafa, Mohamed H. Al Awady and M.A.Ashmawy Figures 5 and6 show that the optimum dose of Fe 2+ can reduce the concentration of COD and phenol to the limits stated in law 4/1994 at dose equal 5 and 8 mg/l respectively Proposed Industrial Wastewater Treatment Units Naphtha Effluent Spent caustic from Naphtha Treatment Unit will be treated according to the Fenton reaction. The collected spent caustic is treated with Acid, Ferrous Sulfate, and Peroxide. This treatment will reduce the phenol, COD and associated TKN content prior to discharge in the main oily water stream. Spent Caustic ph adjustment Fe 2 SO 4 Addition H 2 O 2 Addition Discharge to Oily Water Stream API separator Effluent Effluent from API separator will be treated by flocculation and Dissolved air floatation. This treatment will reduce the Total Suspended Solids, COD, and associated TKN before discharge to the skim basin for dilution. From API Separator Alum Addition Flocculation Dissolved Air Floatation Discharge to Skim Basin The following process flow diagram shows the proposed treatment process. Proposed Industrial Wastewater Treatment Process for Portion 1 (from Naphtha Department- Phenol Removal) Flow 12.5 m3/hr Fe 2+ H 2 O 2 Caustic Soda Flow 12.5 m 3 /hr ph Fe2+ Adjustment Fe2+ ph Adjustment To Existing API Temperature Reduction (Cooling) Schematic Flow Diagram for Industrial Wastewater from Naphtha Department editor@iaeme.com

7 Naphtha Removal From Petroleum Industrial Effluent Proposed Industrial Wastewater Treatment Process for Portion 2 (from Other Departments - COD and TSS Removal) Flow 725 m3/hr Alum dose 100 mg/liter Flow 725 m 3 /hr Flash Mixing Fe2+ tank 1 min Flocculation Fe2+ Tank 15 min Dissolved Flotation Tanks To Existing API 4. CONCLUSION OF THE TREATABILITY STUDY From the previous results the following are concluded that the optimal operating conditions are as follows: 1. Reaction time is 30 minutes to complete the reaction. 2. The Fe 2+ dose is 0.8 g/l. 3. The (30 %) H 2 O 2 dose is 65 ml/l. 4. The starting ph value up to 10, reduced to the level of optimal value of the reaction. 5. The reduction in COD reaches up the required level in law 4/ The reduction in phenol reaches up the required level in law 4/1994 REFERENCES Schematic Flow Diagram for Industrial Wastewater from Other Departments [1] E.T. Yoong, A. P. Biodegradation of High Strength Phenolic Wastewater Using SBR. Wat.Sci.Tec. - Iwa, 43(3) Pp [2] Fica-Piras P (2000) Refinery Effluent Nitrification Studies in Triphasic Bioreactors. MSc Thesis (in Portuguese), Federal University of Rio de Janeiro, Rio de Janeiro. [3] Y. B. Shaheen, R.M. Abd El-Naby, M.A. Adam and A.M. Erfan. Strength and Behavior of Innovative Composite Columns. International Journal of Civil Engineering and Technology, 5(11), 2014, pp [4] G. Ma, A. N. Creating Anoxic and Microaerobic Conditions in Sequencing Batch Reactors Treating Volatile BTX Compounds, Water Science and Technology - Iwa, 43(3) Pp [5] R. M. Abd El-Naby, A. A. Gamal and T. A. El-Sayed. Controlling the Demolition of Existing Structures: An Approach to Analyze the Collapse of the World Trade Center North Tower WTC1. International Journal of Civil Engineering and Technology, 5(11), 2014, pp [6] H.H.P. Fang, D.W. Liang, T. Zhang, Y. Liu, Anaerobic treatment of phenol in wastewater under thermophilic condition. Water Research, 40(3), pp , ISSN DOI: /j.watres February editor@iaeme.com

8 Sherif A. Moustafa, Mohamed H. Al Awady and M.A.Ashmawy [7] Nwaichi, E. O., Akaninwor, J. O. and Wegwu, M. O. Physico chemical properties of effluent from a beverage company. JASEM (Journal of Applied Science and Environmental Management 11(1): [8] Pedro, J. S. Inductive and Resonance Effects on the acidities of phenol, Enols, and Carbonyl αhydrogens, Junior Organic Chemistry 74(2): [9] S. T. Sami Sarfaraz. Anoxic Treatment of Phenolic Wastewater in Sequencing Batch Reactor, Water Research 38, [10] World Bank, Petroleum Refining, Pollution Prevention and Abatement Handbook, World Bank, pp editor@iaeme.com