Recently, Ningbo Huatai Shengfu Polymer Materials Co., Ltd. (hereinafter referred to as “Ningbo Huatai”) has delivered an impressive operational performance from its 400,000‑ton‑per‑year styrene production unit. The facility employs an advanced, proprietary ethylbenzene dehydrogenation process developed by Changzhou Ruihua Chemical Engineering Technology Co., Ltd. (Ruihua Technology), along with Clariant’s high‑performance StyroMax™ UL‑3 catalyst, which features an ultra‑low water‑to‑oil ratio. Since the plant was restarted following a catalyst change in December 2024, multiple key operating metrics have consistently reached new all‑time highs, achieving outstanding performance characterized by long‑term operation, high load rates, low energy consumption, and stable, reliable running.

Ningbo Huatai’s 400,000-ton styrene plant

Since the unit was commissioned following a catalyst changeover, its catalyst activity and selectivity have remained consistently excellent, enabling the plant to operate continuously at a high load of over 100%. In particular, the di‑vinylbenzene (DVB) content in the reactor effluent is extremely low, completely eliminating the risk of main condenser blockage caused by DVB polymerization. This obviates the need for shutdowns and cleaning, thereby supporting long‑term, stable, and efficient operation. The process also effectively reduces raw material consumption and system energy losses, lowers carbon emissions, and delivers multiple benefits—improved product quality, enhanced efficiency, cost reduction, and decarbonization—while setting a new all‑time record for optimal operational performance.

A relevant person in charge at Ruihua Technology stated:

The outstanding performance of the Ningbo Huatai unit underscores the exceptional compatibility and synergistic value of Ruihua’s proprietary ethylbenzene dehydrogenation technology and Clariant’s advanced catalysts. Leveraging Ruihua’s process expertise and pairing it with Clariant’s high‑performance StyroMax UL‑3 catalyst, the solution effectively addresses key industry challenges—high energy consumption, frequent equipment fouling, and short operational cycles—helping customers achieve stable production, improved quality, cost reduction, and carbon footprint mitigation. Looking ahead, Ruihua will continue to deepen its strategic collaboration with Clariant, iteratively refine and optimize its comprehensive styrene‑production solutions, deliver greater value to customers, and drive the industry toward greener, more efficient upgrades.

Yin Wenjing, Senior Sales Manager at Clariant Catalysts, stated:

The stable operation of the StyroMax™ UL‑3 catalyst at Ningbo Huatai’s styrene plant fully demonstrates the product’s outstanding performance in Ruihua‑technology‑based units. We are deeply honored to have established a strategic partnership with Ruihua Technology; by leveraging the complementary strengths of both parties, we effectively help customers achieve long‑term, high‑efficiency plant operations while reducing energy consumption and costs. Looking ahead, Clariant will continue to deepen its innovation in styrene catalysis, integrate digital service capabilities, and collaborate with Ruihua’s advanced processes to sustainably drive green, low‑carbon production across the industry.

Ruihua Technology’s ethylbenzene dehydrogenation process for producing styrene

Changzhou Ruihua Chemical Engineering Technology Co., Ltd. boasts nearly 20 years of extensive experience in styrene technology. Building on China’s early‑stage styrene technologies, the company has introduced numerous innovative improvements and refinements. Its styrene process is continuously being upgraded, with the successful development of a new large‑scale reactor and advanced engineering solutions for high‑temperature piping. These advancements have established distinctive technical strengths, with key performance indicators at an industry‑leading level.

The design adopts a well‑established, widely applied two‑stage vacuum adiabatic dehydrogenation process featuring an intermediate heat exchanger for styrene production, and fully leverages the domestically developed technological advances accumulated over years of research on this process. Its key features are as follows:

(1) It employs a domestically developed negative-pressure adiabatic dehydrogenation process with interstage heat exchange, along with a unique high-temperature system treatment method.

(2) The dehydrogenation reactor employs a uniquely developed domestic radial reactor, with a hyperbolic conical flow distributor that eliminates pressure drop across the perforated plate. By leveraging radial flow technology and optimizing the design of the inlet and outlet flow channels, the reactor’s pressure drop meets the requirements of vacuum‑operated reactions, while the circumferential temperature difference remains below 2°C. This results in high volumetric and catalyst utilization rates. For reactors of comparable size, the production capacity is at least 10% higher than that of the previous generation of domestically produced reactor technology.

(3) The externally mounted horizontal triple‑effect heat exchanger, combined with a specially designed configuration, effectively eliminates thermal stresses, ensures low high‑temperature leakage rates, and facilitates convenient maintenance; the independent ethylbenzene evaporator enables staged heat recovery, delivering high thermal efficiency, reduced failure rates, and long‑term stable operation.

(4) Optimization of materials and expansion compensation for high-temperature pipeline equipment results in reduced investment and extended service life.

(5) In collaboration with Clariant Catalysts, the reactor inlet temperature is low, resulting in reduced by-product formation and lower energy and material consumption.

(6) Optimize the inhibitor injection scheme to suppress polymerization and reduce material losses.

(7) Thermal coupling distillation for the separation of ethylbenzene and styrene results in low steam consumption and mitigates thermal polymerization of styrene.

(8) A styrene recovery tower has been added to replace the flash evaporator, reducing steam consumption by half and improving product recovery.

End-to-end process optimization, in collaboration with Clariant Catalysts, enables multi‑stage heat cascade recovery, with efficient reuse of reaction heat, process waste heat, and low‑pressure by‑product steam from the unit, resulting in superior overall energy and material consumption compared to mainstream processes.

Clariant Styrene Catalyst

Clariant boasts more than 70 years of extensive expertise in the global styrene catalysis market. A key challenge faced by styrene producers is the extreme pressure within the reactor, which can adversely affect the performance of the evaporation system. Thanks to its unique ribbed design, Clariant’s StyroMax UL‑3 catalyst not only enhances selectivity but also significantly improves gas‑flow distribution, reducing pressure drop by 30%–50% compared with conventional cylindrical catalysts and ensuring smoother operation. Since its launch, it has become one of the most cost‑effective styrene catalysts worldwide.

Furthermore, the catalyst’s outstanding performance under low water-to-oil ratios helps significantly reduce energy consumption and associated costs. While conventional catalysts typically deliver superior activity or selectivity only at low water-to-oil ratios, StyroMax UL-3 excels in both simultaneously. Its high catalytic activity boosts productivity, while its exceptional selectivity further minimizes the formation of by‑products.

In addition, Clariant’s digital service platform, CLARITY, provides Huatai with 24/7 real-time catalyst performance data, along with advanced visualization, analytics, and monitoring tools. The platform supports all of Clariant’s catalyst applications and enables the visualization of key operating metrics through a customizable user interface. It includes visualization and optimization tools designed to enhance the performance of catalyst‑related production units, such as increasing throughput and reducing raw material consumption. Customers can also use the platform’s user interface to connect directly with Clariant experts for technical discussions and guidance, thereby achieving more efficient catalyst operations. The platform’s strengths are amply demonstrated by its exceptionally high adoption rate: since its launch, CLARITY has been implemented in over 240 plants, serving more than 800 active users across 31 countries worldwide—and the number continues to grow.

The outstanding operational performance of the Ningbo Huatai unit represents a successful implementation of Ruihua’s advanced integrated process technology, Clariant’s high-performance catalysts, and an integrated digital operations‑and‑maintenance solution. Moving forward, Ruihua will continue to deepen its strategic collaboration with Clariant, leveraging the complementary strengths of both parties to further optimize green styrene production solutions, enabling customers to build efficient, low‑carbon, and stable production systems, and driving the industry’s high‑quality, sustainable transformation.