Gasoline Additives: Product Overview, MMT Focus, and Global Development Trends

I. Main Categories of Gasoline Additives and Their Advantages & Disadvantages

As core chemical agents for improving fuel performance and protecting engines, gasoline additives have formed a market pattern with multiple categories and segmented functions. The mainstream products include the following four categories:

(I) Oxygenated Compounds

Core Representatives: Methyl Tertiary Butyl Ether (MTBE), Ethyl Tertiary Butyl Ether (ETBE), Tertiary Amyl Methyl Ether (TAME)

Core Functions: Promote complete combustion of fuel through oxygen atoms in molecules, increase octane number, reduce emissions of carbon monoxide and unburned hydrocarbons. They are currently the most widely used basic additives.

Advantages: Stable octane number improvement effect, excellent miscibility with gasoline, no metal residues, no additional wear on engines, moderate production costs, and suitable for large-scale gasoline production. Under China's National VI B standard, adding 3%-5% volume ratio of ETBE can increase gasoline octane number by 2.3 units and reduce CO emissions by 12.7%.

Disadvantages: Energy density is slightly lower than that of pure gasoline; excessive addition may lead to a slight increase in fuel consumption; MTBE has strong water solubility and may contaminate groundwater if leaked, so its usage ratio has been restricted in some regions.

(II) Detergent-Dispersants

Core Representatives: Polyetheramine (PEA), Polyisobutylene Amine (PIBA)

Core Functions: Adsorb carbon deposits inside engines through amphiphilic molecular structure, prevent aggregation of colloid deposits, protect key components such as fuel injectors and intake valves, and improve combustion stability.

Advantages: Significant cleaning effect—PEA can achieve a carbon deposit removal rate of 63% on the piston top of gasoline direct injection (GDI) engines, while PIBA is more suitable for intake system cleaning of multi-point injection vehicles; no adverse residues, can be used for a long time, and effectively extend engine service life.

Disadvantages: High production cost of PEA resulting in high terminal product prices; continuous use for 3-5 times is required to show the best effect, with no obvious effect in a single use; low-concentration products have limited cleaning power and require strict matching of addition ratios.

(III) Metal Organic Antiknock Agents (with MMT as the core)

Core Representatives: Methylcyclopentadienyl Manganese Tricarbonyl (MMT), Ferrocene

Core Functions: Regulate free radical reactions through nanoparticles generated by pyrolysis during combustion, inhibit engine knock, and efficiently increase gasoline octane number. They are traditional core products for low-cost antiknock solutions.

Advantages: High octane number improvement efficiency—adding 8.3mg Mn/L of MMT to RON 92 gasoline can increase the Anti-Knock Index (AKI) by 1.5 units and thermal efficiency by 1.2%; low addition ratio, no change to the basic composition of gasoline, and production cost much lower than that of ether-based and PEA-based products.

Disadvantages: Combustion produces metal residues such as MnO₂, which are prone to depositing on spark plugs, three-way catalytic converters and other components, affecting catalytic converter activity and engine ignition efficiency; restricted or banned in most environmentally strict regions globally (e.g., China has prohibited intentional addition since the National V standard, and the EU has gradually tightened restrictions since 2000); long-term high-concentration use may increase engine maintenance costs.

(IV) Functional Auxiliaries (Antioxidants, Rust Inhibitors, etc.)

Core Representatives: BHT/BHA derivatives, Organic amine compounds

Core Functions: Antioxidants delay gasoline oxidation and deterioration, extend storage period; rust inhibitors protect metal components of fuel systems from corrosion, adapting to complex storage and usage environments.

Advantages: Extremely low addition amount (10-30ppm) to exert effects, small cost ratio; good compatibility with other additives, no impact on core fuel performance.

Disadvantages: Single function, unable to directly improve power or cleaning effect; excessive addition may react with other components, affecting fuel stability; product quality varies greatly in the market, and inferior products may produce precipitates.

 II. In-Depth Analysis of MMT Products

(I) Core Mechanism of Action

The core value of MMT lies in efficient antiknock performance and octane number improvement. Its mechanism of action is different from traditional oxygenated compounds: through pyrolysis during combustion, it generates MnO₂ nanoparticles that act as free radical capture centers to promote the conversion of hydrogen peroxide free radicals to hydroxyl radicals, regulating the branching ratio of combustion reactions, thereby inhibiting knock. This catalytic antiknock pathway enables significant effects at low addition amounts, and it was once widely used for octane number improvement in the unleaded gasoline era, but has been gradually restricted due to environmental issues.

(II) Technical Maturity

As a classic product with over half a century of industrial application, MMT has extremely high maturity in basic production technology: the core synthesis pathway is stable, product purity and performance consistency are strong, and the application technology system is improved. Consensus has been formed in the industry regarding the addition ratio for different gasoline grades and compatibility schemes. However, due to environmental policy restrictions, its technological upgrading focuses on the direction of "low residue and low manganese content". Nevertheless, limited by its own chemical properties, the upgrading space is limited, and it has gradually become a "transitional technology", marginalized in the technological iteration of mainstream markets.

(III) Global Regional Production and Usage

1. Production Distribution

From the perspective of global production pattern, MMT production is still concentrated in three major regions: Asia-Pacific, North America, and Europe. However, China's production has completely shifted to export-oriented, and the global market scale showed a slow contraction trend in 2024. The specific distribution is as follows:

Asia-Pacific Region: Accounts for over 55% of global production. China is the core producing country (relying on the cost advantage of the coal chemical industry chain), but there is no legal application demand domestically, and 100% of the products are exported to regions with loose environmental standards such as Southeast Asia, the Middle East, and Africa. India and South Korea have only a small amount of production capacity, serving only local special scenarios such as non-road oil (not civil gasoline).

North America: Accounts for about 25% of global production. The United States is the main producing country, with products mainly of high-purity and low-impurity specifications, supplying small and medium-sized local refineries (for non-civil gasoline blending) and the Latin American market. Production capacity is shrinking year by year.

Europe: Accounts for about 15% of global production, concentrated in non-EU countries such as Russia and Turkey. Products are mainly adapted to low-standard gasoline production in Eastern Europe, the Balkans, and Africa; Western Europe (including EU member states) has no MMT production capacity.

Other Regions (Latin America, Middle East, Africa): Account for less than 5% of global production, with small-scale local production mainly meeting the demand for low-environmental-standard oil products in the region.

2. Regional Usage

Regional differences in MMT usage are mainly driven by environmental policies, oil product standards, and cost requirements. China has completely prohibited the addition of MMT to civil gasoline. The geographical classification and usage status are corrected as follows:

Asia-Pacific Region: The world's largest consumer market (accounting for over 60% of global consumption), but consumption is concentrated in Southeast Asia, ASEAN countries, and some South Asian regions. These regions have relatively loose environmental standards (the manganese content limit in some countries is still 18mg/L), and MMT is widely used in medium and low-grade gasoline due to cost advantages. However, countries such as Vietnam and Thailand have begun to follow China in tightening manganese content limits (gradually reducing to below 8mg/L), and demand is showing a downward trend. In China, illegal addition of MMT may only exist in unqualified non-standard gasoline, and there is no legal usage scenario in the formal market.

North America: Usage is restricted but there is still rigid demand, accounting for about 20% of global consumption. The United States, Canada, and other countries allow limited use in non-civil gasoline (such as industrial equipment oil) (≤8mg Mn/L). MMT has been basically eliminated from civil gasoline, and only a small amount of residual demand remains for special oil in remote areas.

Europe:

Western Europe (including Switzerland, Germany, France, etc.): Strictly prohibits use in civil gasoline. As a non-EU country, Switzerland implements environmental standards equivalent to the EU. It has prohibited intentional addition of manganese-containing additives since 2005, with a mandatory limit of ≤2mg/L for manganese content in gasoline, consistent with China's National VI standard, and no legal usage space.

Eastern Europe (including EU member states such as Hungary, Poland, Czech Republic): Follows the EU Directive 2009/30/EC, with a manganese content limit of ≤2mg/L in gasoline and prohibits intentional addition of MMT. Only trace residues exist in non-road oil for some old industrial equipment (accounting for less than 3% of regional consumption).

Non-EU Eastern European countries (such as Serbia, Bosnia and Herzegovina): Relatively loose environmental standards, with a manganese content limit of 8-15mg/L. MMT is still used in small amounts in medium and low-grade civil gasoline (accounting for about 12% of regional consumption), but faces pressure from EU policy transmission and is gradually tightening restrictions.

Russia and Turkey: MMT is still used to a certain extent in civil gasoline (manganese content limit of 10-18mg/L), but both production capacity and demand are showing a shrinking trend year by year.

Latin America, Middle East, Africa: Stable demand, accounting for about 10% of global consumption. These regions have loose environmental regulations and are sensitive to gasoline production costs. MMT remains the mainstream antiknock agent for medium and low-grade gasoline due to its cost-effectiveness. However, with the global coordination of environmental standards, some countries have launched restriction policies, and long-term demand will gradually shrink.

III. Future Development Trends of the Industry

(I) Overall Industry Trends

Green Environmental Protection Drives Formula Upgrading: Global carbon neutrality goals and stringent emission standards (such as National VI B and Euro 7) are promoting the transformation of additives towards "low ash, no residue, and biodegradable". Bio-based additives and metal-free antiknock agents have become research hotspots, and the proportion of composite functional formulas will increase from the current 34% to 68% by 2030.

Coexistence of High Performance and Customization: Engines are developing towards high compression ratio, miniaturization, and hybridation, spurring demand for additives with multiple synergistic functions such as "antiknock + cleaning + anti-preignition". Scenario-based customized formulas are emerging, such as special detergents for GDI engines and antiknock maintenance agents for hybrid vehicles, with rapid growth in segmented products.

Technological Iteration Accelerates Domestic Substitution: The technology of third-generation detergents represented by PEA is constantly maturing, domestic production capacity is continuously expanding, and import dependence is declining. Traditional metal-based additives such as MMT are gradually withdrawing from the mainstream market, and their share is being replaced by metal-free products such as ETBE and alkylate oil.

Intensified Market Structure Differentiation: The high-value-added high-end product market is dominated by a few multinational enterprises, while in the mid-to-low-end market, local enterprises with cost advantages and regional channel advantages are enhancing their competitiveness. MMT manufacturers are accelerating the transfer of production capacity to overseas markets with loose environmental standards or transforming to other products.

(II) Development Trends of MMT Products

Continuous Compression of Compliant Living Space: Global environmental restrictions on metal-based additives will be further tightened. It is expected that by 2027, Southeast Asia, the Middle East, and non-EU Eastern European countries will successively reduce the manganese content limit to below 5mg/L, basically eliminating the effective addition space of MMT, which can only remain in a very small number of regions without implemented environmental standards.

Accelerated Shrinkage of Application Scenarios: Demand for MMT in civil gasoline will decrease year by year, and its global share in the civil market is expected to be less than 3% by 2030, with only a small amount of demand remaining in special scenarios such as non-road oil and industrial equipment oil. China will continue to maintain a comprehensive ban, and the regulatory crackdown on illegal addition will be further strengthened.

Transfer of Production Capacity to Low-Standard Regions: MMT manufacturers will accelerate the transfer of production capacity to regions with loose environmental policies such as Africa and Latin America. Production capacity in traditional producing countries such as China and the United States will continue to withdraw, and the overall industry scale will show a "shrinking migration" trend.

Gradual Replacement by Metal-Free Antiknock Agents: The technological maturity and cost competitiveness of alternative products such as ETBE, bio-based ethers, and high-purity alkylate oil are continuously improving. It is expected that by 2030, the share of MMT in the global gasoline additives market will drop from the current 12.8% to below 3%, eventually becoming a niche special-purpose product.