Ethylene production cost
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I would like to ask everyone how to calculate the production cost of ethylene for various processes? What is the raw material consumption per unit?
Below, energy consumption is calculated using a 660 kt ethylene plant as an example. The energy consumption of an ethylene plant mainly consists of three components: fuel, steam, and electricity. The following values are known:
**Fuel consumption:**
Methane, hydrogen – 28,025 kg/h
Mixed C5 – 9,812.5 kg/h
Mixed C9 – 9,425 kg/h
**Steam consumption:**
Ultra-high pressure steam (input) – 88.28 t/h
Medium pressure steam (output) – 130.68 t/h
Low pressure steam (output) – 4.19 t/h
**Electricity consumption:** 12,250 Kw
**Ethylene production:** 82.5 t/h
The calculations are as follows:
**(1) Fuel**
The calorific value of the fuels is as follows:
Methane, hydrogen – 48,070 kJ/kg
Mixed C5 – 41,870 kJ/kg
Mixed C9 – 41,870 kJ/kg
Total calorific value of fuels = 28,025 × 48,070 + 9,812.5 × 41,870 + 9,425 × 41,870 = 2,152.64 (GJ/kg)
**(2) Steam**
The calorific values of the steam used in the ethylene plant can be found in tables:
Ultra-high pressure steam – 3,169.94 kJ/kg
Medium pressure steam – 2,704.72 kJ/kg
Low pressure steam – 2,559.55 kJ/kg
Heat from input steam = 88.28 × 10³ × 3,169.94 = 279.84 (GJ/h)
Heat from output steam = 130.68 × 10³ × 2,704.72 = 353.45 (GJ/h)
Heat from output low-pressure steam = 4.19 × 10³ × 2,559.55 = 10.72 (GJ/h)
**(3) Electricity**
1 Kw = 10,241 kJ/h
Electricity energy consumption = 10,241 × 12,250 = 125.45 (GJ/h)
**(4) Hourly energy consumption**
Q_input = 2,152.64 + 279.84 + 125.45 = 2,557.93 (GJ/h)
Q_output = 353.45 + 10.72 = 364.17 (GJ/h)
Q_input – Q_output = 2,193.76 (GJ/h)
**(5) Energy consumption per ton of ethylene**
(Energy input – Energy output) / 82.5 = 2,193.76 / 82.5 = 26.59 (GJ/t)
**(6) Conclusion**
Based on the consumption of fuel, steam, and electricity, the energy consumption per ton of ethylene in this plant is 26.59 GJ (equivalent to 6.35 million BTU). If the energy required for cooling water is taken into account, it should be added to this value. Summarize the above calculations in the table below. Table of comprehensive energy consumption for fuel and power in ethylene plants – Item, Energy Consumption, Unit of Consumption, Quantity Unit, Coefficient Unit, Total Amount. Fuel: GJ/t, 26.09; 1 GJ/t × 26.09 = 26.09. Ultra-high pressure steam: 11.8 Mpa, 520°C, t/t, 1.07 GJ/t; total = 3.17 GJ/t, further 3.39 GJ/t. Medium pressure steam: 1.55 Mpa, 290°C, t/t, -1.58 GJ/t; total = 2.70 GJ/t, further -4.27 GJ/t. Low pressure steam: 0.4 Mpa, 200°C, t/t, -0.051 GJ/t; total = 2.56 GJ/t, further -0.13 GJ/t. Electricity: Kw·h/t, 148.48 kJ/Kw·h; 10,241 GJ/t, 1.52. Comprehensive consumption: GJ/t, 26.6. ① Negative values indicate output.
**Fuel consumption:**
Methane, hydrogen – 28,025 kg/h
Mixed C5 – 9,812.5 kg/h
Mixed C9 – 9,425 kg/h
**Steam consumption:**
Ultra-high pressure steam (input) – 88.28 t/h
Medium pressure steam (output) – 130.68 t/h
Low pressure steam (output) – 4.19 t/h
**Electricity consumption:** 12,250 Kw
**Ethylene production:** 82.5 t/h
The calculations are as follows:
**(1) Fuel**
The calorific value of the fuels is as follows:
Methane, hydrogen – 48,070 kJ/kg
Mixed C5 – 41,870 kJ/kg
Mixed C9 – 41,870 kJ/kg
Total calorific value of fuels = 28,025 × 48,070 + 9,812.5 × 41,870 + 9,425 × 41,870 = 2,152.64 (GJ/kg)
**(2) Steam**
The calorific values of the steam used in the ethylene plant can be found in tables:
Ultra-high pressure steam – 3,169.94 kJ/kg
Medium pressure steam – 2,704.72 kJ/kg
Low pressure steam – 2,559.55 kJ/kg
Heat from input steam = 88.28 × 10³ × 3,169.94 = 279.84 (GJ/h)
Heat from output steam = 130.68 × 10³ × 2,704.72 = 353.45 (GJ/h)
Heat from output low-pressure steam = 4.19 × 10³ × 2,559.55 = 10.72 (GJ/h)
**(3) Electricity**
1 Kw = 10,241 kJ/h
Electricity energy consumption = 10,241 × 12,250 = 125.45 (GJ/h)
**(4) Hourly energy consumption**
Q_input = 2,152.64 + 279.84 + 125.45 = 2,557.93 (GJ/h)
Q_output = 353.45 + 10.72 = 364.17 (GJ/h)
Q_input – Q_output = 2,193.76 (GJ/h)
**(5) Energy consumption per ton of ethylene**
(Energy input – Energy output) / 82.5 = 2,193.76 / 82.5 = 26.59 (GJ/t)
**(6) Conclusion**
Based on the consumption of fuel, steam, and electricity, the energy consumption per ton of ethylene in this plant is 26.59 GJ (equivalent to 6.35 million BTU). If the energy required for cooling water is taken into account, it should be added to this value. Summarize the above calculations in the table below. Table of comprehensive energy consumption for fuel and power in ethylene plants – Item, Energy Consumption, Unit of Consumption, Quantity Unit, Coefficient Unit, Total Amount. Fuel: GJ/t, 26.09; 1 GJ/t × 26.09 = 26.09. Ultra-high pressure steam: 11.8 Mpa, 520°C, t/t, 1.07 GJ/t; total = 3.17 GJ/t, further 3.39 GJ/t. Medium pressure steam: 1.55 Mpa, 290°C, t/t, -1.58 GJ/t; total = 2.70 GJ/t, further -4.27 GJ/t. Low pressure steam: 0.4 Mpa, 200°C, t/t, -0.051 GJ/t; total = 2.56 GJ/t, further -0.13 GJ/t. Electricity: Kw·h/t, 148.48 kJ/Kw·h; 10,241 GJ/t, 1.52. Comprehensive consumption: GJ/t, 26.6. ① Negative values indicate output.
Cash operation costs are part of Solomon Company’s performance analysis; they represent the total cost of all cash payments. Non-cash costs such as depreciation and interest expenses are not included in this calculation. Similarly, raw materials are also not taken into account in the calculation of cash operation costs, in accordance with international practices. The unit cash operation cost is the total of all cash operation costs divided by the total ethylene production. According to the performance analysis conducted by Solomon Company, the cash operating costs for ethylene production at Sinopec Corporation are significantly higher than international advanced levels, especially compared to those in the Asia-Pacific region. The table below shows the statistics for cash operation costs in 1999: Global average ($/t), Asia-Pacific region ($/t), Sinopec average ($/t)*, PetroChina ($/t). Subtotal of fixed costs: 43.22, 27.31, 32.22, 7.19. Annual maintenance costs: 6.29, 5.67, 4.72, 6.53. Subtotal of variable costs: 98.47, 97.95, 134.87, 152.31. Administrative costs: 2.58, 3.44, 0.09, 4.52. Total cash operation costs: 150.56, 134.34, 175.88, 190.54
Thank you very much for the information provided by the person above; I will study it carefully
Outdated information.. Ugh! :The evaluation standard abroad for L is now: XXX t SRF/t C2; the standard commonly used domestically is: xxx t Standard Oil/t C2=
There are many factors that influence this, and the calculated value might differ significantly from the actual one
Can the material consumption indicators be shared? Do I need it right now? :handshake :handshake :handshake