Abstract: The article selects four plant-wide processing plans for the production of paraxylene. According to different raw materials, they are divided into two plans: heavy oil to aromatics and condensate to aromatics. The five-year average price of the domestic market from 2015 to 2019 is selected. , carry out benefit calculation and cost analysis of unit paraxylene, with the purpose of obtaining the recommended reference range and internal relationship of the complete processing fee of unit paraxylene, raw material processing cost and total processing cost, so as to provide raw material selection and plan for the enterprise in the early decision-making stage. Choose to provide reference value.
Keywords: paraxylene; processing flow; benefit calculation; unit cost analysis; raw material cost; complete processing fee
Introduction
Para-xylene, abbreviated as “PX” in English, is a colorless and transparent liquid, which is an aromatic hydrocarbon. It is an important intermediate product connecting oil refining and chemical industry. Toluene is the most important product among its subordinate products and is also the leading raw material in the polyester industry.
1. Paraxylene market situation and supply and demand development trends
China’s paraxylene industry is currently in a growth stage because of many The reason is that China’s paraxylene industry has experienced a long period of slow development, and the explosive expansion of the downstream PTA industry driven by the rapid development of the polyester industry has caused an imbalance in the supply and demand of paraxylene, and import dependence has climbed to more than 50%. However, this pattern will change in 2019-2020. Thanks to the successive commissioning of new units of Hengli Petrochemical, Sinochem Hongrun and Hainan Refining Phase II, China’s PX output in 2019 was 14.67 million tons, and domestic supply increased by 11.65% year-on-year. In 2020, PX production will reach 19.86 million tons, import volume will be reduced to 13 million tons, and self-sufficiency capacity will be enhanced again. In 2020, China’s PX market will gradually transition to a stage of balanced supply and demand, and import dependence will also be significantly reduced.
2. Benefit calculation and cost analysis ideas
Due to the above reasons, paraxylene has become the main processing method for many refining and chemical companies. The target product of the overall process. This article selects 4 plant-wide refining projects whose target products are paraxylene, and conducts benefit calculations and cost analysis, hoping to find some internal connections and patterns. The whole-plant refining and chemical project has simple raw materials, does not involve intermediate raw materials and product pricing, and has a good reference value for real-life enterprises to estimate costs and predict benefits. The overall processing process of the example project selected in this article has the characteristics of short process, reasonable processing depth, clear target products, and similar design ideas, which improves the comparability and rationality of the analysis.
The idea behind this benefit calculation and cost analysis is to determine the type and quantity of incoming and outgoing materials based on the overall process flow of the entire plant for each project. Then select a representative price system to price the materials. Calculate the economic benefits based on the new whole plant project. Then compare and analyze the raw material cost per unit PX of different raw materials and the complete processing fee per unit PX to find out the approximate internal relationship between the cost of paraxylene and the selected processing raw materials and processing costs, which will provide a reference for raw material selection and benefit prediction for subsequent projects. data.
3. Benefit calculation and cost analysis
3.1 Sample project overview and material comparison
For the four new plant-wide paraxylene projects selected, the raw materials for projects A and B are heavy oil; the raw materials for projects C and D are condensate (light crude oil). The PX output of the four projects is 1.6 million tons/year, 2.8 million tons/year, 1 million tons/year and 1.6 million tons/year respectively. Due to the differences in the nature of raw materials and the quantity of products, the device composition and scale of each project are somewhat different, but the overall processing flow idea is to maximize the production of paraxylene, without producing gasoline, coal and diesel products, and the by-product light naphtha is taken away or As the raw material for ethylene cracking in the downstream industry, other by-products include benzene, commercial liquefied gas, sulfur, heavy aromatics and petroleum coke, etc., which are directly sold. The production of paraxylene in the four projects is realized by large-scale aromatics complex units using naphtha as raw material. The comparison of the whole factory materials of the four projects is shown in Table 1.
3.2 Calculated Price
The price adopted is the five-year average price of the domestic market from 2015 to 2019, and is based on the raw materials and products The nature is determined. For a unified caliber, the freight of raw materials entering the factory is not taken into account, and the prices of raw materials are calculated based on prices excluding consumption tax. The specific prices are shown in Table 2, and the prices in the table do not include VAT.
3.3 Benefit Calculation
In the calculation, the basic parameters are consistent with those in the financial evaluation of regular project feasibility study reports, with reference to China “Technical and Economic Parameters and Data for Feasibility Study of Petrochemical Projects in China” released by the Economic and Technical Research Institute of Petrochemical Corporation. After calculation, under the selected price system, the main technical and economic indicators of the four projects are summarized in Table 3.
It can be seen from Table 3: Projects A and B that use heavy oil as raw materials have better benefits, and the financial internal rate of return after income tax exceeds the benchmark rate of return, which are 12.83% and 15.49% respectively; while those that use light crude oil as raw materials Projects C and D have poor returns, and the financial internal rate of return after income tax does not exceed the benchmark rate of return.
Table 1 Comparison of materials for each project
Table 2 Raw material product price list unit: yuan/ton
3.4 Unit Cost Analysis
The main difference between the four selected projects is the raw materials. Due to the different raw materials used,This results in a large difference in the economic benefits of the final project. Therefore, it is very necessary to analyze the raw material cost and total processing cost of unit paraxylene products.
In cost analysis, the following principles are adopted for raw material cost allocation: products other than paraxylene are regarded as by-products, and by-product income deducting a certain proportion of profit is deducted from the raw material cost (the profit rate in this article is temporarily Take it as 10%), and then divide it by the paraxylene product output to get the raw material cost per unit of paraxylene. The unit complete processing fee is obtained by multiplying the proportion of the raw material cost minus by-products to the total raw material cost multiplied by the total complete processing fee. The cost analysis results are shown in Table 4.
3.4.1 Cost analysis results of projects A and B using heavy oil as raw material
(1) The unit raw material cost of projects A and B accounts for the total unit processing cost The proportions are 80.77% and 74.02% respectively, and the average unit raw material cost is about 3,000 yuan/ton.
(2) The complete unit processing fees of projects A and B account for 19.23% and 25.98% of the total unit processing costs respectively. The reference value of unit complete processing fee for the hydrocracking-aromatics combined route using heavy oil as raw material is 800 to 979 yuan/ton.
Table 3 Summary of main technical and economic indicators of the project
Table 4 Unit PX cost analysis table
( 3) The ratio coefficient of the unit raw material cost of project A and the weighted average raw material unit price is 1.42, and the ratio coefficient of project B is 1.28. When the feed price is determined, the company can estimate the raw material cost per unit of paraxylene based on this coefficient, which can provide the manufacturer with a reference prediction of the cost.
(3) The total unit processing costs of projects A and B are 4,158 yuan/ton and 3,767 yuan/ton respectively, which can also be understood as the cost price of producing paraxylene. The paraxylene price used in the calculation is 6,100 yuan/ton, which is higher than the total unit processing cost and has a certain profit margin.
3.4.2 Cost analysis results of projects C and D using condensate as raw material
(1) The unit raw material cost of projects C and D accounts for the total unit cost The proportions of processing costs are 85.88% and 87.94% respectively. The average unit raw material cost is 5,900 yuan/ton.
(2) The complete unit processing fees of projects C and D account for 14.12% and 12.06% of the total unit processing cost respectively. The reference value of unit complete processing fee for the hydrocracking-aromatics combined route using condensate as raw material is 774 to 994 yuan/ton.
(3) The ratio coefficient of unit raw material cost and weighted average raw material unit price of project C is 1.74, and the ratio coefficient of project D is 1.62. The price of condensate is higher than that of heavy oil and other heavy crude oils, so the unit PX raw material cost of producing aromatics from condensate is higher.
(4) The total unit processing cost and PX cost price of projects C and D are 7125 yuan/ton and 6416 yuan/ton respectively. The price of paraxylene in the price system used in this cost price ratio is 6100 yuan. / ton high, so it is not difficult to understand why the two projects C and D are less efficient under the selected price system.
3.5 Conclusion
(1) The cost of raw materials has been deducted from the calculation of the complete processing fee, which is only related to the complexity of the processing technology. The degree is related to the level of manufacturing management, and there is little difference in the complete processing fee per unit PX of each project. The reference range of the complete processing fee for PX units of aromatic hydrocarbon manufacturing projects using similar processing procedures is 700 to 1,000 yuan/ton.
(2) According to the above analysis results, the ratio coefficient of the raw material cost per unit PX to the weighted average raw material price is between 1.3 and 1.4 for the processing plan of producing aromatics from heavy oil. Processing plan, the ratio coefficient is between 1.6 and 1.75. When an enterprise selects raw materials, it can use this ratio coefficient to estimate the cost of raw materials per unit PX.
(3) The total unit processing cost is the sum of the unit complete processing fee and the unit raw material cost. The reference range of the total processing cost of heavy oil to aromatics: 180# fuel oil price 2164 * coefficient (1.3~1.4) + complete processing fee (700~1000), that is, 3513~4030 yuan/ton. The reference range of the total processing cost of condensate to aromatics: South Pas condensate price 3489 * coefficient (1.6 ~ 1.75) + complete processing fee (700 ~ 1000), that is, 6282 ~ 7106 yuan / ton. In practice, the enterprise can multiply the known prices of alternative processing raw materials by the above ratio coefficient according to the above method to obtain the raw material cost per unit PX of each raw material, and then add the complete processing fee per unit PX to obtain the total unit PX. Processing cost, that is, the cost price of PX. Compare the obtained cost price with the PX market price and analyze the size of the profit margin, thereby providing some reference for raw material selection and cost prediction.
4. Conclusion
(1) The benefit calculation results of the four projects show that the benefits of producing aromatics from heavy oil are better than those of condensate oil Production of aromatics. When selecting raw materials and product solutions, companies should pay attention to evaluating the properties of light crude oil and selecting a more suitable process route to produce aromatics.
(2) The average market price from 2015 to 2019 selected in the benefit calculation in this article was the five years when international crude oil prices were relatively high. In these five years, Brent crude oil averaged 60 US dollars per barrel. level. The results may change amid lower international crude oil prices.
(3) The number of example projects selected in this article is limited, and the project stage is in the planning or feasibility study stage, and the depth is shallow. It is only used as a reference for companies to estimate costs and benefits in the early decision-making stage. Now there are For more examples, you can continue to do more in-depth research. </p
