Chemical Safety Usage and Handling - Lab Report Example

Name: Instructor: Course: Date: Water Treatment Plant Chemical Safety Usage and Handling Handling of Chemicals Chlorine, Hydrochloric Acid and Sodium Hydroxide are the most dangerous chemicals in the WTP. Hydrochloric acid (HCl), in itself, is a strong acid that has a concentration of up to 35 %. This, therefore, means that it should be handled with a lot of care since it can cause severe skin burns as well as cause damage to metallic materials. Sodium Hydroxide (NaOH), on the other hand, is a corrosive material which can cause skin burns and if inhaled can damage one’s lungs. Chlorine is a poisonous gas which when inhaled in high concentrations can kill instantaneously. Carbon Dioxide (CO2), on its part, is a suffocating gas and this means that an oxygen tank ought to be taken. It is recommended that the other chemicals should be ingested. However, if they come into direct contact with the skin, it is important that one washes thoroughly. Chemicals are supposed to be kept in a cool area that is not under direct sunlight. Additionally, chemicals should not be stored near combustible materials. They should also be kept away from humid areas. Fork lifts are used to move these chemicals. How and Where to the Use Chemicals 1. Lime Powder and CO2 Lime, in form of lime water, is injected into drinking mixers to change distillate water into drinkable water. This lime will react with carbon dioxide (CO2) to produce carbonhydocarbonate. That reaction is represented by the equation below: Ca(OH)2+CO2 CaHCO3 (Calsium Bicarbonate) 2. Sea Water In order for it to have the taste as well as the minerals, sea water is added to the drinking water. The conductivity is measured to know how much sea water to add to the drinking water. Conductivity ought to be maintained at 350 µs/cm and 450 µs/cm. It should be noted that the greater the conductivity, the lower the sea water we will add. 3. Chorine Chlorine is used as a disinfectant to remove the bacteria and marine organisms (algae) from the drinking water. The concentration of these additives should range between 0.4 ppm and 0.6 ppm. Chlorine is also essential in controlling the algae growth in the sea water, sterilizing drinking water as well as cooling the water system. 4. Potassium Permanganate (KmNO4) This chemical is used to oxidize the Carbon Monoxide (CO) to Carbon Dioxide (CO2). Additionally, it is used to remove any MEA or ash carry over. Its main characteristic in this process is that it is a strong oxidizing agent. 5. Mono Ethanol Amine (MEA) Monoethanol Amine is used in carbon dioxide generator plant with concentration of 15% solution to separate CO2 from other gases (absorb CO and CO2 between 40 and 800C) and release CO and CO2 above 800C. 6. Tri-Sodium Phosphate (Na3PO4) Tri-Sodium Phosphate is used in GUP for boiler water conditioning to control traces of hardness and to adjust pH. It is used as anticorrosion in both drinking and distillate mixers at a concentration of 3% because lime is used in this case. (Nowadays, drinking mixers are out of service). It is equally used in the boiler injected in the discharge of the boiler feed pumps to draw at a concentration of 5%. 7. Hydrochloric Acid (HCl) and Sodium Hydroxide (NaOH) It is not used in the WTP anymore but was used in the regeneration of the polishing lines. Hydrochloric acid was used for regeneration of WTP ‘cation’ resin. It is also used in the adjustment of the neutralization pit ‘pH’. Sodium Hydroxide on the other hand is used as an anion resin regenerator. It is also used to adjust the neutralization pit ‘pH’. 8. Diethanol Hydroxyl Amine (DEHA) It is a mixture of steamate and cartrol. It is an oxygen excavanger. It is also used to remove the oxygen from the feed water before it goes to the boiler to prevent corrosion. This mixture is injected into the suction header. 9. Cortrol It is a chemical used in the boiler in order to increase the pH value to between 9 and 10 to make it alkaline (basic) to protect the boiler and tubes (boiler protection). 10. Antiscale It is prepared in the WTP and dosed in the MSF dosing tank to prevent scaling. 11. Corrshield It is a chemical that is injected into the secondary cooling systems to minimize scaling and to kill algae. Additionally, if pH or conductivity reduces, it is injected into the system. 12. Soda Ash It is a solution that is used to remove all the sulphur components from the inert gas. CO2 Plant Operation Basic Overview The CO2 generating plant produces liquid CO2 from the combustion of natural gas by washing, compressing, refrigerating and liquefaction. The washing plant is of the absorption type. The boiler is of the short flame fire-tube-smoke tube type where a “mono-ethanol-amine” solution at 15% in water covers the fire-tube bundle. Mounted on top of the boiler is a stripper-fractioner which is a vertical vessel. Operation In the boiler, a mixture of oxygen, fuel gas and ignition are on the tube side of the boiler. The inert gas released from the combustion goes through the inert gas fan to the soda tower. In the soda tower, a reaction occurs between the inert gas and the soda ash (Sodium Carbonate, Na2CO3). Mono-ethanol-amine (MEA) is taken from the boiler and then taken through a heat exchanger to reduce the temperature and finally through a pump and a second heat exchanger (secondary cooling water, scw). From there, it will be sprinkled from the top of MEA tower where it will come into contact with the inert gas and absorb all the carbon monoxide (CO) and carbon dioxide (CO2). All other gases are then released into the atmosphere. The rich MEA (rich in CO and CO2) goes through a pump and then the original heat exchange to increase the temperature and then to the boiler. In the stripper on top of the boiler, the temperature is increased hence resulting into CO and CO2 being released from the MEA solution. From there, the CO and CO2 will go through a SCW to cool the temperature and then to the bubbler while the MEA water goes back to the boiler. From the bubbler, it goes direct to the water wash tower (water scrubber) where water is sprinkled to clean the CO2 and remove any KMNO4 carry over. It then goes to a compressor so as to increase the pressure to 17 bar. It again goes through the heat exchange to decrease temperature to the CO2 dryer which removes all water particles. It then goes to the CO2 filter, followed by CO2 receivers, then the CO2 goes to the liquefier before going to the pre-intercooler. The CO2 then goes to the liquefier to change it from gas to liquid which then goes to the liquid CO2 storage tank. When needed in gaseous form, it can go through the heater to turn it back into gas. It then proceeds to the mixers. Note: CO2 is produced so that it can react with lime to produce bicarbonate hardness. CO2+Ca(OH)2 CaHCO3 (Calcium Bicarbonate) Interlock and Protection of Raw and Pure Condensate Pumps 1. Tank Level 2. Motor Overload Protection 3. Safety Valve 4. Low Pressure Startup 5. Stand-in motor pump (starts at 5.5 bar). Start-Up and Shutdown Procedures of the CO2 Plant Chemical Preparations 4 kg of Sodium Carbonate/ Soda Ash (Na2CO3) 2 kg of Potassium Permanganate (KMNO4) Start-Up Procedures N/B: All valves ought to be open in the CO2 plant. 1. Fill the soda tower; KMNO4 vessel and water washer tower. 2. Fill the boiler with MEA (400l) and pure condensate water (45% in DCS, 90% in sight glass). 3. Fill absorber tower with pure condensate water. 4. Circulate MEA, start rich MEA/ Lean MEA pumps. MEA flow should be 1000 liter/ hour. 5. Control boiler level, put level control valve on auto. 6. Keep one air fan (open discharge valve) on manual; inert fan (open succharge + discharge valves) on auto. 7. Start the air fan and purge the boilers for 5 minutes. 8. Keep the dumper in min position. 9. Place the inert gas fan on auto position and then start the ignition using ignition line. 10. Wait for a few seconds until main gas line electro valve energizes and then open the main gas valve gradually and air valve too. 11. Release damper valve gradually as you check that the vent valve is closed and inert gas fan is closed too is closed. 12. Start on auto. 13. Gradually open air valve to increase firing (MEA flow should be maintained at 1500 liters/ hour and furnace pressure kept at normal 20m bar). 14. When boiler reaches 1.4 bar, open KMNO4 vessel inlet valve gradually. When compressor suction pressure reaches 1.4 bar, start compressor upkeep suction valve closed and dischargeable valve open, then gradually open compressor suction valve. 15. Freon compressor can be started when the receiver pressure reaches above 16 bar. Shutdown Procedures 1. Stop firing by pressing push button open manual vent valve. 2. Keep pumps running while MEA and soda ash cools down. Once it is cooled, pumps can be switched off. 3. Stop CO2 gas compressor immediately and then close gas line isolation valves. 4. Drain all the vessels and then flush all the vessels with water thoroughly. Chemical Safety Usage Working with every single chemical needs to have special techniques and clothes in order to avoid any hazards. Description of each chemical is attached with the report. Polishing Lines Flow Diagrams (Cation and Mixed Bed) Consumers Steamate Dosing Chemical Dosing Pumps and their Operation Procedures 1. POY Dosing Pumps (Concentration of about 5%) Six pumps are used to distillate mixer 1 and 2 (3 on each side). 2. Boiler POY Dosing Pumps (7 pumps) 3 pumps to boiler 1 and 2; 2 pumps to steam converter and 2 pumps to WHRB 28. 3. POY Dosing to Drinking Mixers 1 and 2 (6 pumps) 3 pumps to each mixer. Note: All the 6 pumps are on standby since POY is injected into the distillate mixers. 4. DEHA Dosing to Boiler Side (6 pumps) 3 pumps to boiler 1; 3 pumps to boiler 2 and 2 pumps to boiler 3. 5. Corrshield Dosing to Secondary Water Tube (4 pumps) 2 pumps to secondary water 1; 2 pumps to secondary water 2. Note: It is used to increase pH so that corrosion doesn’t happen in the tube and also to kill algae. 6. Lime Dosing to Drink Mixers 1 and 2 (6 pumps) 3 pumps to each drink mixer. 7. Sea Water Propulsion Pump Mixing by Chlorine Cylinder Pressure 4 Pumps to Drink Water 1 and 2 Note: We’ve Y chlorinator injectors; each chlorinate injector is connected to a pump. It is used to increase water conductivity and to kill any bacteria. 8. (2) POY Transfer Pumps to POY Dosing Tanks 9. Steamate to Outlet of Polishing Line (Product) before entering the pure tank 3 pumps. Condensate Cleaning and Polishing Plant Condensate polishing plant consists of two trains of cation and mixed beds in parallel. Each train is capable of processing 300m3/hr. The raw condensate pumping group consists of 4 centrifugal pumps rated at 2*165m3/hr and 2*80m3/hr with a discharge pressure of 8 bar. Pure condensation pumps are rated at 2*200m3/hr and 2*80m3/hr respectively with a discharge pressure of 8 bar. The cartridge filters are used to remove suspended matter from turbine and brine heater condensate. All cation and mixed bed exchangers are also suitable for the demineralization of water. HCl and NaOH for regeneration are stored in welled outdoor storage tanks made of carbon steel, rubber-lined; each of 20m3 net capacity. Two transferring pumps for each chemical with capacity of 20 ton/hr each are used to transfer the chemicals from the trucks to the storage tanks. Regeneration Pumping Group .2*100 m3/hr regeneration water pumps; .1*300 m3/hr back wash water pump and .1*300 m3/hr circulation pump. .1*20 m3 acid storage tank; . 1*20 m3 NaOH storage tank; .1*500 m3 raw condensate storage tank and . 1*500 m3 pure condensate storage tank. Raw Condensate Tank Sources Distillate water dosed from distillate tanks; distillate water undosed from MSF #3 production; condensate steam turbine #1 and #2; condensate pumps (between 2 boilers). Pure Condensate Tank Sources From polishing lines (A or B); From demi plant. Drinking Water Quality Ph should be between 7.8 and 8.3 controlled by PO4; Conductivity should be between 350 and 500µs/cm controlled by sea water; Chlorine should be 0.07 controlled by chlorine; Hardness (CaH) should be between 24 and 27 PPM. Distillate Tank Water Quality Ph should be between 7.8 and 8.5; Conductivity should be below 55µs/cm. Raw Tank Water Quality Ph should be between 8 and 9.5 pH; Conductivity should be below 50µs/cm. Turbine condensates (Conductivity should be below 7 µs/cm). Neutralization Basin All water from the drains in the WTP is taken to neutralization basin where the pH value is tested automatically to see if it is alkaline or acidic. If it is alkaline, we add HCl to neutralize the water. If it is acidic, we add caustic soda to neutralize the water. The water has to have a neutral pH value because the water will get sent to the sea and if it’s alkaline or acidic it will harm the sea life. Drinking Water Production 650 m3/hr 650 m3/hr 650 m3/hr 550 m3/hr 550 m3/hr To raw tanks as Make up (undosed) Soda+PO4 Soda+PO4 PO4 PO4 References Edzwald, James. Water Quality and Treatment. 6th ed. New York: McGraw-Hill, 2011. Print.  Read More