The world's largest single-scale PDH unit was successfully renovated

As of June 7, the propylene tower of the world's largest 900,000 tons/year propane dehydrogenation (PDH) plant of Jinneng Chemical (Qingdao) Co.
, Ltd.
has been in continuous and stable operation for 18 days after energy-saving and efficiency-enhancing transformation, marking the transformation project.
One-time driving success
.

According to reports, the device adopts the Catofin process of Lummus, which is the world's first and the largest single-scale PDH device at present
.
Compared with before the transformation, the efficiency of the propylene tower has been greatly improved, the reflux ratio has been reduced by 20%, and the separation accuracy has been significantly improved.
, greatly improving the propylene yield
.

The propylene tower is the core equipment of the PDH plant
.
According to reports, the diameter of the upper tower of Jinneng Chemical's propylene tower is 11.
3 meters, and the diameter of the lower tower is 11.
9 meters, both of which are designed with six overflow trays, which are difficult to design and require high separation efficiency
.

The ADV-TDD patented technology of Beijing Zehua Chemical Engineering Co.
, Ltd.
was adopted in the energy-saving and efficiency-enhancing transformation of the propylene tower of Jinneng Chemical's PDH unit
.
This technology is the third generation high-efficiency tray technology developed on the basis of the classic ADV high-efficiency tray, combined with the newly developed hanging downcomer technology with precise liquid distribution function developed by Beijing Zehua
.
Compared with the ADV tray, the ADV-TDD tray can further increase the processing capacity and the efficiency of the tray can also be significantly improved, especially in the application of four overflow and six overflow trays, the efficiency advantage is more prominent
.

The person in charge of Beijing Zehua Technology introduced: "To achieve the best separation efficiency with multiple overflow trays, the liquid-to-gas ratio of each bubbling zone needs to be the same
.
Therefore, we need to accurately distribute the gas and liquid in each bubbling zone
.
The larger the number of overflows on the tray, the greater the necessity of this precise distribution
.
The tray can realize the precise distribution of the liquid in each bubbling area through the optimal design of the downcomer structure, so that each bubbling area can be accurately distributed.
The liquid and gas are completely matched to ensure the same liquid-to-gas ratio in each bubbling zone, thereby maximizing the efficiency of multiple overflow trays
.
”

On April 1, more than 200 on-site construction workers from Beijing Zehua entered the tower in an orderly manner through 11 manholes, and began to carry out local accurate transformation of the 251-story six-overflow tray
.
After nearly 20 days of continuous work day and night, the construction was successfully completed
.
The operation results of the device show that the propylene tower exhibits excellent separation performance and achieves the dual goals of energy saving and quality improvement
.

With the continuous increase of propylene demand and the greener way of hydrogen by-product, large-scale PDH units have become a trend, and units with a scale of more than 900,000 tons/year are already being planned, which also means that larger-sized propane will appear.
Propylene separation tower
.
Beijing Zehua's third-generation high-efficiency tray technology is especially suitable for such large and super-large towers with multiple overflows
.