Prospective analysis of propane dehydrogenation to polypropylene is unique in the industry

The diversification trend of polypropylene has become more and more obvious in recent years.
Among them, the development trend of light weight of raw materials is prominent, and the growth rate of propylene by-product of traditional naphtha cracking has slowed down.
Propane dehydrogenation to polypropylene series is one of them.
The products of the "dark horse" category in the polypropylene industry have once become the focus of attention due to their low cost and high profit advantages.
Even this year when the cost of raw materials is rising, they can still maintain a rapid development momentum.
What is the reason?

I.
Development Status of Domestic Propane Dehydrogenation to Propylene Process Technology

The international propane dehydrogenation to propylene process is shown in the table below
.

Table 1 International Propane Dehydrogenation to Propylene Process

Data source: public information collation

After more than 20 years of continuous development and improvement of propane dehydrogenation to propylene technology, the industrial application is becoming more and more mature
.
At present, the global dehydrogenation of propane to propylene mainly includes the Oleflex process of UOP, the Catofin process of Lummus, the Star process of Uhde, the PDH process of Linde, Snamprogetti-Yarsintez The FBD process jointly developed by the company,
etc.
The most widely used propane dehydrogenation processes in the industry are the Oleflex process of UOP and the Catofin process of Lummus
.
The catalysts used are mainly Pt-based and Cr-based
.

The propane dehydrogenation process has a relatively short history of development in China, but its development momentum is extremely strong.
In 2013, the first domestic propane dehydrogenation unit, the 600,000-ton/year unit of Tianjin Bohua, was put into operation, and the propane dehydrogenation series was launched in China
.
Because the PDH process has the advantages of single raw material, short process, high propylene yield, low investment cost and high economy, it has attracted the attention of many domestic investors
.

2.
Statistical analysis of domestic production capacity of PP from propane dehydrogenation

According to statistics from Longzhong Information, the current domestic production capacity of propane dehydrogenation to PP totals 4.
7 million tons, accounting for 14.
65% of the national total PP production capacity.
Compared with the 7% propane dehydrogenation capacity in 2015, the proportion of propane dehydrogenation capacity has increased by 7.
65%.
It can be seen that in recent years, propane dehydrogenation capacity Hydrogen production of polypropylene is developing rapidly
.
According to the regional division, the highest production capacity ratio in East China accounts for 45% of the total PP production capacity, South China accounts for 39%, and North China accounts for 16%.
East China is currently the main area for the production of PP from propane dehydrogenation.
1.
6 million tons/year polypropylene plant, Shaoxing Sanyuan 500,000 tons/year polypropylene plant
.
Southern China is mainly concentrated in Dongguan Juzhengyuan 600,000 tons/year, Sinochem Quanzhou 550,000 tons/year and Zhongjing Petrochemical 700,000 tons/year polypropylene plant
.
From the perspective of future capacity layout, the expansion of propane dehydrogenation units in South China is relatively intensive, and will be the main area leading the future capacity expansion of PDH to polypropylene
.

3.
Comparative analysis of the cost and profit of polypropylene dehydrogenation to polypropylene

From the analysis and comparison of the cost and gross profit of polypropylene dehydrogenation from propane dehydrogenation from 2017 to 2021, it is found that the profit of polypropylene dehydrogenation from propane dehydrogenation is currently the best among the five different raw material categories
.
From 2017 to 2020, its average profit was 1908 yuan/ton, while the average profit value from January to October this year shrank to 883 yuan/ton, a decrease of 60.
05% compared with the same period last year (average 2210 yuan/ton)
.
Analysis of the reasons for this, as the price of propane this year is boosted by the high price of overseas natural gas shortage, the cost of producing polypropylene from propane dehydrogenation this year is significantly higher than the same period in previous years, and the average cost of producing polypropylene from propane dehydrogenation from January to October 2021 is 7919 yuan / ton Compared with the same period last year, the average cost (5,643 yuan / ton) increased by 40.
33%, while the price of polypropylene from propane dehydrogenation increased by 17.
74% compared with the same period last year.
status quo
.

4.
Analysis of advantages and disadvantages of propane dehydrogenation technology

The advantage of propane dehydrogenation technology is to greatly improve the yield of propylene products
.
Steam cracking produces propylene, and the highest propylene yield is only 33%, while the total yield of propylene produced by catalytic dehydrogenation can reach more than 80%.
Due to the single raw material in the process, the products are only hydrogen and propylene and are easy to separate, so the propylene yield is high
.
Secondly, the production cost of propane dehydrogenation is only closely related to the fluctuation of propane price, and the price of propane is not directly related to the price of naphtha and the propylene market
.
Propane is a low-value gas.
In the past, it was mainly used as a fuel.
Its chemical value has not been well developed.
PDH can convert low-value propane into high-value propylene, thereby improving corporate efficiency
.
Finally, compared with the traditional refinery by-product and steam cracking process, PDH has a shorter process flow, simpler installation, lower investment and operating costs, and under medium and high oil prices, PDH is more profitable than the traditional refinery gas process and steam The pyrolysis process is high
.

The disadvantage is that the PDH unit has high requirements for the purity of propane, the purity requirement is 97%, and the volume fraction of impurity gaseous sulfur is less than 100 μL/L.
Domestic propane mainly comes from the by-product of the refinery.
The by-product liquefied petroleum gas has a high sulfur content, so the quality of propane cannot meet the raw material requirements of the PDH process, and the supply of propane is highly dependent on imports
.
Since the cost of raw material propane accounts for about 80% of the total cost, the economy of the process is mainly determined by the price difference between propane and propylene.
The lower the price of propane, the more profitable the project will be
.

5.
Prospects for the future production of polypropylene from propane dehydrogenation

In the context of the continuous development of domestic demand in the domestic economy, the diversified competition mode of polypropylene has become the norm, so the competition mode of various raw materials will also be more intense, so the cost and profit competition is particularly important
.
Due to the single raw material of PDH process, the price difference between propane and propylene is the main indicator to determine the economical type of PDH.
With the continuous increase of domestic PDH units, the gap of raw material propane is gradually increasing, and imported propane is still in a long-term growth trend
.
In the future, how to have a long-term, stable and low-price propane price, and at the same time have the advantages of sufficient propane storage facilities and port terminal logistics facilities, will become a key factor affecting the development of PDH enterprises
.
In the future, with the gradual improvement of the integration trend of the polypropylene industry chain, the ability of enterprises to resist risks will also be gradually improved
.