ZSM-22 Zeolite in Lubricant Base Oil Production: Unlocking Efficiency and Stability

The global demand for high-performance lubricants is increasing rapidly, driven by stricter emission regulations, the rise of electric vehicles, and the demand for longer oil drain intervals. Traditional Group I base oils, derived from solvent refining, are no longer sufficient to meet the performance requirements of modern engines and industrial systems.

This shift has placed catalytic hydroprocessing and hydroisomerization at the heart of base oil production. Among the catalysts available, ZSM-22 (TON-type zeolite) has emerged as a promising material for lubricant base oil upgrading due to its unique pore structure, high thermal stability, and ability to control isomerization without excessive cracking.

The Industry Challenge: Producing Stable, High-VI Base Oils

Modern lubricant base oils must satisfy several key requirements:

• High Viscosity Index (VI): Ensures stable performance across temperature extremes.

• Low Pour Point: Maintains fluidity in cold conditions.

• Oxidation Resistance: Prevents degradation over long operating periods.

• Environmental Compliance: Reduced sulfur, nitrogen, and aromatics content.

Traditional catalysts, such as ZSM-5, face challenges due to their medium-pore structure (10-membered ring, ~5.5 Å pores), which often leads to over-cracking of feedstock into light gases instead of desired isomerized molecules. This reduces yield and creates inefficiencies.

ZSM-22 addresses this pain point. With its TON framework, one-dimensional 10-membered ring channels (~4.5 × 5.5 Å), and low diffusion restrictions, it enables selective hydroisomerization of long-chain paraffins into high-quality base oils without excessive cracking losses.

ZSM-22: Structural Advantages in Lubricant Base Oil Production

1. One-Dimensional Channel System:
   The TON framework allows linear molecules to enter and undergo selective isomerization, avoiding bulky intermediates that cause catalyst deactivation.

   
   

2. Controlled Isomerization:
   Compared to ZSM-5, ZSM-22 exhibits higher selectivity for mono-branched isomers, which significantly improves viscosity index (VI) and reduces pour point.

   
   

3. Thermal and Hydrothermal Stability:
   ZSM-22 can operate under the severe conditions of hydroisomerization units (350–420°C, 3–8 MPa H₂), ensuring long catalyst life cycles.

   
   

4. Synergy with Metals (Pt/ZSM-22, Pd/ZSM-22):
   When loaded with noble metals, ZSM-22 demonstrates high hydroisomerization activity while suppressing cracking.

   
   

Comparative Performance: ZSM-22 vs. ZSM-5 and SAPO-11

According to Weitkamp et al., Applied Catalysis A (2001), ZSM-22 demonstrates superior selectivity in hydroisomerization of long-chain n-paraffins, outperforming ZSM-5 in lubricant yield and quality.

Applications of ZSM-22 in Base Oil Upgrading

1. Hydroisomerization of Fischer–Tropsch Wax:

• Produces Group III+ base oils with high VI and low pour point.

• Reduces dependence on conventional crude-derived feedstocks.




2. Upgrading Heavy Gas Oils:

• Converts long-chain paraffins into high-value base oil molecules.

• Extends feedstock flexibility for refiners.

  
  

3. Blending in Modern Lubricants:

• ZSM-22 derived base oils enhance engine oils, hydraulic fluids, and transmission oils.

• Meets API Group III specifications for synthetic-like performance.

  
  

Pain Point Resolution: Why ZSM-22 Matters

• Problem 1: Over-Cracking in ZSM-5 Systems
  → Solution: ZSM-22 balances isomerization and minimizes cracking, improving lube yields.

• Problem 2: Poor Cold Flow Properties in Conventional Oils
  → Solution: ZSM-22 enhances pour point depression through selective isomerization.

• Problem 3: Catalyst Deactivation due to Aromatics
  → Solution: TON framework resists coke formation, enabling longer cycles.

Future Outlook: ZSM-22 as a Commercial Catalyst

The commercial relevance of ZSM-22 is steadily increasing. Refiners are exploring Pt/ZSM-22 hydroisomerization catalysts for Fischer–Tropsch derived wax upgrading, with promising results in both pilot and commercial units.

At Yutai Zeolite, we are preparing to introduce ZSM-22 to our product line, offering high-purity TON zeolite tailored for lubricant base oil applications. Specifications, data sheets, and application guides will be published upon official launch.

FAQs

Q1: What makes ZSM-22 different from ZSM-5 in base oil production?
ZSM-5 tends to over-crack heavy paraffins, leading to lower lubricant yields. ZSM-22, with its TON structure, provides controlled isomerization and better cold flow properties.

Q2: Can ZSM-22 be used with Fischer–Tropsch waxes?
Yes. ZSM-22 is highly effective in hydroisomerizing FT wax into high-VI, low pour point Group III base oils.

Q3: How does ZSM-22 improve cold start performance in lubricants?
By selectively producing mono-branched isomers, ZSM-22 significantly lowers pour point, ensuring fluidity at low temperatures.

Q4: Is ZSM-22 commercially available?
Yes, ZSM-22 catalysts (often Pt/ZSM-22) are in commercial use. At Yutai Zeolite, we are preparing to launch high-quality ZSM-22 powder and catalyst support for industrial partners.

Q5: What industries benefit from ZSM-22 based base oils?
Automotive lubricants, aviation oils, industrial machinery oils, and hydraulic systems all benefit from ZSM-22 upgraded base oils.