112663 Utilities

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.
4.2.1.1 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.
4.2.1.2 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.
4.2.1.3 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.