4.1. Utilities 4.2.1. Water The plant required water, for cooling water and steam. Water supply is obtained from Selat Sunda, approximately 10 km near the Cilegon Industrial Area where the plant is located. Before using it for the utilities, the seawater must get treatments to remove the impurities through desalination. Desalination is a process to remove of salts and minerals from a target (in this casi is sea water). The salts and mineral from sea water need to treat because it can be crystalized in equipment. These factor can be dangerous for the equipment. The cleaned seawater is then pumped to the equipment as fresh tank water to produce steam. 184.108.40.206 Cooling Water Requirement Cooling water is used for heat exchange between cooling water stream and hot process streams. Therefore, the water loss from drift loss could exist. The water loss from drift loss is usually 0.1-0.2% from the total inlet cooling water. This plant assumes 0.1% drift loss. Table X.X Table Cooling Water Requirement Equipment E-104 T in T out Q (̊C) (̊C) (kJ/s) 235 92 543,06 Q (kJ/h) 1955016 Cp water Mass flow (kJ/kg.K) (kg/h) 4,2 3255,104895 3255,104895 TOTAL Table X.X Calculation of Makeup Cooling Water Losses Number Amount (kg/h) Drift loss (0,1%) (W) 0,10% 3,2551049 Total Makeup Cooling Water (kg/h) 3,2551049 Total amount of water is 𝑇𝑜𝑡𝑎𝑙 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑚𝑒𝑛𝑡(𝑘𝑔/ℎ) = 𝐹𝑒𝑒𝑑 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑚𝑒𝑛𝑡 + 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑚𝑒𝑛𝑡 𝑇𝑜𝑡𝑎𝑙 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑚𝑒𝑛𝑡(𝑘𝑔/ℎ) = 3,255.104895 + 3,255.1049 𝑇𝑜𝑡𝑎𝑙 𝑤𝑎𝑡𝑒𝑟 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑚𝑒𝑛𝑡(𝑘𝑔/ℎ) = 3,258.36 Cooling water requirement equal to 3,258.36 kg/h. 220.127.116.11 Water Requirement The water is supplied from the ocean, which has high total hardness. Therefore, this plant needs to do the water treatment before using the seawater. The method to treat the seawater is by desalination unit with some micro and ultra filtration unit. To ensure a continuous supply of water, it was built on the location of the water intake which is also a pre-treatment of seawater. Moreover, water is pumped to the plant to be processed and used as needed. Table X.X Table Water Requirement T in T out Q (oC) (oC) (kJ/s) E-107 28 48 935.98 Q-101 30 46 E-106 46 30 Equipment Cp water Mass flow (kJ/kg.K) (kg/h) 3,369,528 4.2 40,113.42857 114.13 4,129,668 4.2 61,453.39286 233.53 840,708 4.2 12,510.53571 Q (kJ/h) 114,077.3571 TOTAL The water requirement is about 114,077.3571 kg/h. 18.104.22.168 Water Treatment The water is supplied from the ocean, which has high total hardness. Therefore, this plant needs to do the water treatment before using the seawater. The method to treat the seawater is by desalination unit with some micro and ultra filtration unit. Function of this unit are to remove the impurities through desalination . To ensure a continuous supply of water, it was built on the location of the water intake which is also a pre-treatment of seawater. Moreover, water is pumped to the plant to be processed and used as needed. 4.2.2. Steam There are some heating system in this plant which uses steams as the hot fluids for heating systems. The steam will be heated by heater before supplied to the equipment. The steam is needed to heat air, MMA, Acetone, Toluene, and used in evaporator. Table X.X Steam Requirement in Plant Before HEN Equipment T in T out (̊C) (̊C) Q (kJ/s) Q (kJ/h) Cp water Mass flow (kJ/kg.K) (kg/h) E-101 30 92 503.81 1,813,716 4,2 6,965.1152 E-102 30 92 2089.83 7,523,388 4,2 28,891.6590 E-103 30 92 8.92 32,112 4,2 123.3180 EV-101 92 180 623.97 2,246,292 4,2 6,077.6299 E-105 30 120 320.44 1,153,584 4,2 3,051.8095 45,109.5316 TOTAL After applying HEN, there is a stream process whose heat is exchanged with another stream process. Table below shows the result of steam, requirement after HEN. Table X.X Steam Requirement in Plant Before HEN T in T out (̊C) (̊C) E-101 30 E-102 Cp water Mass flow (kJ/kg.K) (kg/h) 1,813,716 4,2 6,965.1152 1546.77 5,568,372 4,2 21,383.9171 32,112 4,2 123.3180 623.97 2,246,292 4,2 6,077.6299 320.44 1,153,584 4,2 3,051.8095 Q (kJ/s) Q (kJ/h) 92 503.81 30 92 E-103 30 92 8.92 EV-101 92 180 E-105 30 120 Equipment TOTAL 37,601.7896 It shows that after using HEN, the plant save some steam. Steam requirement before using HEN is 45,109.5316 kg/h, while after using HEN the requirement can be reduce until 37,601.7896 kg/h. 4.2.3. Fuel Fuel needed in the plant is used for diesel generator as an electricity supplier. It is known that the fuel heating value (Hv) is 19,200 Btu/lb, and the combustion efficiency (η) is 85%. Electricity power needed for the generator is 400 kW, or 1,364,876.64 Btu/hr. The fuel requirement calculation: 𝑀𝑎𝑠𝑠 = (𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑖𝑡𝑦 𝑛𝑒𝑒𝑑𝑒𝑑) 𝑥 (𝐻𝑣 𝑥 η) 𝑀𝑎𝑠𝑠 = (1,364,876.64 Btu 𝐵𝑡𝑢 ) 𝑥 (19,200 𝑥 0.85) hr 𝑙𝑏 𝑀𝑎𝑠𝑠 = 83.63 𝑙𝑏/ℎ𝑟 𝑀𝑎𝑠𝑠 = 37.92 𝑘𝑔/ℎ𝑟 The fuel requirement for the generator if it is assumed a power outage for 1 hour per day is: 𝐹𝑢𝑒𝑙 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = 37.92 𝑘𝑔 ℎ𝑟 𝑥 24 ℎ𝑟 𝑑𝑎𝑦 𝐹𝑢𝑒𝑙 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = 910.44 𝑘𝑔/𝑑𝑎𝑦 The total fuel requirement with a safety factor of 20% is: 𝑇𝑜𝑡𝑎𝑙 𝑓𝑢𝑒𝑙 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = 910.44 𝑘𝑔 𝑥 (1 + 0.2) 𝑑𝑎𝑦 𝑇𝑜𝑡𝑎𝑙 𝑓𝑢𝑒𝑙 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = 1,092.53 𝑘𝑔/𝑑𝑎𝑦 Knowing the fuel density is 850 kg/m3, so the volume is: 𝑉𝑜𝑙𝑢𝑚𝑒 = 𝑇𝑜𝑡𝑎𝑙 𝑓𝑢𝑒𝑙 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 𝑉𝑜𝑙𝑢𝑚𝑒 = 1,092.53 𝑘𝑔/𝑑𝑎𝑦 850 𝑘𝑔/𝑚3 𝑉𝑜𝑙𝑢𝑚𝑒 = 1,285.33 𝑙𝑖𝑡𝑟𝑒/𝑑𝑎𝑦 4.2.4. Electricity Electricity needed for the plant is used for process equipment, and is supplied by PLN and a diesel generator. The electricity power needed for each equipment can be seen in the Table x.x. Table Ошибка! Текст указанного стиля в документе отсутствует..1 Electricity power needed for each equipment No. Equipment Code Function Power (HP/hr) 1. P-101 Flowing MMA to Reactor 7.50 2. P-102 Flowing Acetone to the Reactor 0.02 3. P-103 Flowing Toluene to the Reactor 0.02 4. C-101 Flowing the Evaporator output to the Reactor 8.30 5. R-101 Polymerization reaction to form PMMA (stirrer) 29.50 6. CR-101 Cutting 7.26 7. RD-101 Drying PMMA chip 27.47 8. P-105 Transferring BPO raw materials into Silo 6.23 9. To S-102 Transferring PMMA products into Silo (conveyor) 35.96 Total (in HP/hr) 122.26 Total (in kWh) 91.17 To guarantee the continuity of production and company performance, one generator unit with diesel fuel is provided, which can run the generator if a power outage occurs, with the capacity of 700 kW. 4.2.5 Nitrogen Nitrogen is used to drive BPO into the reactor as well as to remove oxygen in the reactor during polymerization because the oxygen will react with benzoyl peroxide radicals and inhibit the polymerization process. Needs of nitrogen will be obtained from PT Air Liquid (Alindo) in Cilegon. 4.2.6 Waste Water Treatment 4.2.7 Comparison of Utility Requirement Pre- HEN and Post-HEN The comparison of utility energy between before and after HEN is used to know how much heat that has been recovered by the integration of heat in the process fluids. The calculation of utility requirement before and after the implementation of HEN is made on the following table. Table X.X Efficiency of HEN for Hot and Cold Utility Q (kW) Utility Difference Efiiciency (kW) (%) 3199,155 659,825 0,171 116,765 659,825 0,849 Before After HEN HEN Hot 3858,98 Coold 776,59 The HEN system manages to decrease the necessity up to 17.1% for hot utility and 84.9% for cold utility. The application of HEN gives significant results in saving cold utility steam usage.