Forestry biomass liquid fuel
1Key Takeaways
This standard establishes specifications for the production, quality, and testing of liquid fuel derived from forest biomass. It outlines requirements for raw materials, processing methods, and performance criteria to ensure consistency and reliability in the final product. The document also includes procedures for sam…
2Expert Interpretation
This in-depth analysis of the LY/T 3451-2025 industry standard, "Forestry Biomass Liquid Fuels," covers the classification, raw material requirements, core technical indicators, inspection rules, and safety specifications for hydrocarbon, ester, alcohol, ether, and blended liquid fuels. It analyzes the standard's role in promoting the industrialization of forestry biomass energy and provides professional guidance for production, inspection, and application.
Background and Strategic Significance of Standard Development
The release of LY/T 3451—2025 "Forestry Biomass Liquid Fuels" marks a new stage in the construction of my country's forestry biomass energy standardization system. Driven by global energy transition and the "dual carbon" goal, developing and utilizing non-grain biomass resources has become a key path to ensure energy security and reduce carbon emissions. This standard systematically integrates the technical specifications for the conversion and utilization of forestry "three residues" (logging residues, timber residues, and processing residues), energy forest fruits and seeds, etc., filling the gap in biomass liquid fuel product standards in the forestry field.
The standard drafting units brought together 28 industry-university-research institutions, including Beijing Forestry University, Sinopec Research Institute of Petroleum Processing, and Tsinghua University, reflecting the characteristics of cross-domain collaborative innovation.
The technical content not only references 42 existing national and industry standards, but also fully considers international biofuel development trends, providing authoritative technical support for the large-scale production and market access of forestry biomass liquid fuels in my country. The standard clearly defines 11 key terms, constructing a clear conceptual system for forestry biomass liquid fuels. Among them, forestry biomass liquid fuel (3.2) is defined as "a liquid combustible substance that can generate heat or power, made primarily from forestry biomass through physical, chemical, or biological conversion processes." This definition highlights the forestry attributes of the raw materials, the diversity of processes, and the energy function of the product.
Dual-Dimensional Classification Framework
The standard establishes a dual-dimensional classification system of raw material source and chemical composition:
| Classification Dimensions | Main Categories | Typical Raw Materials | Main Products | Application Fields |
|---|---|---|---|---|
| By Production Raw Materials (4.1) | Oil Crops | Tung Oil, Sapindus mukorossi, Jatropha curcas Fruit/Seeds | Hydrocarbons, Ester Fuels | Diesel Substitutes for Vehicles |
| Starches | Cassava, Oak, Quercus glauca Starch Parts | Alcohol and Ether Fuels | Fuel Ethanol and Additives | |
| Lignocellulosic Fuels | Forestry Residues and Energy Forests | Ester and Blended Fuels | Industrial Boiler Fuels | |
| By Chemical Composition (4.2) | Hydrocarbon Liquid Fuels | Various Forestry Biomass | Second-Generation Biodiesel and Biojet Fuel | Aviation and Vehicle Engines |
| Ester Liquid Fuels | Oil-Based Biomass | Fatty Acid Methyl/Ethyl Ester | Vehicle and Marine Engines | |
| Alcohol-based liquid fuels | Starch-based biomass | Green methanol, fuel ethanol | Internal combustion engines, aircraft engines | |
| Ether-based liquid fuels | Various forestry biomass | Polyoxymethylene dimethyl ether, etc. | Fuel additives | |
| Blended liquid fuels | Lignocellulosic fuels | Pyrolysis oil, liquefied oil | Industrial kiln fuels | |
| Blended liquid fuels | Multiple component blends | Alkane and alcohol-ether blends | Cooking stoves, agricultural machinery |
Application Case: A biodiesel company uses tung oil fruit to produce fatty acid methyl esters. Following standard requirements, it established a raw material traceability system, recording the collection location, time, and forest type for each batch of raw materials. Through carbon footprint accounting, the product's total life-cycle carbon emissions are reduced by more than 65% compared to fossil diesel, earning green product certification and a market premium.
In-depth Analysis of Technical Indicators for Six Types of Fuels
Chapter 6, "Technical Requirements," is the core technical content of the standard, specifying detailed physicochemical indicator requirements for each of the six types of liquid fuels.
Key Indicator Comparison Analysis
| Fuel Type | Density Range (kg/m³) | Flash Point Requirement (°C) | Calorific Value Requirement (MJ/kg) | Sulfur Content Limit | Special Indicators |
|---|---|---|---|---|---|
| Hydrocarbon Liquid Fuels | 750~810 | ≥60 | ≥40 (lower) | ≤10 mg/kg | Cetane Number ≥50, C15~C18 Alkanes ≥70% |
| Ester Liquid Fuels | 820~900 | ≥130 | ≥32 (low position) | ≤10 mg/kg | Fatty acid methyl esters ≥96.5%, total glycerol ≤0.240% |
| Alcohol-based liquid fuels | 720~820 | ≥12 | ≥22 (high position) | Not directly specified | Water content ≤0.2%, inorganic chlorine ≤8.0 mg/L |
| Ether-based liquid fuels | 650~1100 | ≥20 | ≥20 (low position) | ≤10 mg/kg | Oxygen content 15~40%, cetane number ≥55 |
| Mixed liquid fuel | 1100~1300 | ≥45 | ≥15 (high) | ≤0.05% (mass) | Particulate matter ≤1%, water content ≤30% |
| Blended liquid fuel | 800~900 | ≥20 | ≥40 (high) | ≤10 mg/kg | Polycyclic aromatic hydrocarbons ≤11%, cold filter plugging point ≤-5℃ |
Technical Considerations for Setting Indicators
1. Relationship between Density and Calorific Value:Density range reflects the differences in molecular structure among different fuels. Hydrocarbon fuels have the closest density to traditional diesel (750~810 kg/m³), ensuring compatibility with existing engine systems. Ester fuels have a higher density due to oxygen content (820~900 kg/m³), and their calorific value is correspondingly lower to ≥32 MJ/kg, which is consistent with international biodiesel standards (such as EN 14214).
2. Strict Control of Sulfur Content:Except for blended liquid fuels, the sulfur content limit for the other five types of fuels is ≤10 mg/kg, meeting the China VI diesel standard level and reflecting high environmental protection standards. Modern analytical techniques such as
3. Low-Temperature Flowability Indicators: Cold filter plugging point (CPP), pour point (POP), and other indicators are set for different application scenarios. The CPP for hydrocarbons and blended liquid fuels is required to be ≤-5℃ to ensure performance in cold regions. Due to their higher water content (≤30%), blended liquid fuels require a pour point of ≤-9℃ to prevent freezing in winter.
4. Stability Requirements: Oxidation stability is a key indicator for biofuels. Hydrocarbon fuels require a total insoluble matter ≤2.5 mg/100mL (SH/T 0175), and ester fuels require an oxidation induction period of ≥6.0 h at 110℃ (NB/SH/T 0825). These indicators ensure the stability of the fuel during storage and transportation.
Technology Evolution Analysis: Compared with earlier biofuel standards, the indicator system of LY/T 3451—2025 is more refined. For example, the fatty acid methyl ester content requirement for ester-based liquid fuels is ≥96.5%, higher than the ≥96.0% requirement in GB/T 20828—2015 "Biodiesel for Blending Diesel Engine Fuels (BD100)," reflecting advancements in production technology. Simultaneously, a new requirement has been added for the C15~C18 alkane content (≥70%) of hydrocarbon-based liquid fuels. This is a characteristic indicator for the hydrotreating process used to produce second-generation biodiesel, demonstrating the diversification of technological routes.
Inspection Rules and Quality Control System
Chapter 7 establishes a complete dual-track quality control system of **factory inspection + type inspection**.
Differentiated Design of Factory Inspection Items
The standard specifies 10 factory inspection items for each of the six types of fuels (Table 7), reflecting the principle of "key control and classified management":
- Hydrocarbon fuels:Focus on combustion performance indicators such as distillation range (50% recovery temperature ≤300℃) and 10% distillate carbon residue (≤0.3%).
- Ester fuels:Emphasis on conversion efficiency indicators such as total glycerol content (≤0.240%) and fatty acid methyl ester content (≥96.5%).
- Alcohol fuels:Control corrosive impurity indicators such as water content (≤0.2%) and inorganic chlorine (≤8.0 mg/L).
- Blended fuels:Monitor crude product characteristic indicators such as particulate matter (≤1%) and acid value (≤100 mg/g).
Marking, Packaging, Transportation, Storage and Safety Specifications
Chapters 8-9 reference a series of basic standards such as GB 190, GB 13690, GB 30000.7, and NB/SH/T 0164, constructing a complete product circulation and safety management system.
Safety Classification:According to GB 30000.7 "Classification and Labelling Specifications for Chemicals Part 7: Flammable Liquids", forestry biomass liquid fuels must be classified and labeled according to their flash point:
- Alcohol fuels (flash point ≥ 12℃) belong to Class 3 flammable liquids
- Hydrocarbon fuels (flash point ≥ 60℃) have relatively low fire hazard
- Ester fuels (flash point ≥ 130℃) have high storage safety
Packaging and Transportation:Packaging containers must comply with GB 190 "Packing Marking of Dangerous Goods", and transportation and storage must comply with NB/SH/T 0164 "Rules for Packaging, Storage, Transportation and Delivery Acceptance of Petroleum Products". Special emphasis is placed on storage conditions of protection from light, airtightness, and low temperature (-5℃~15℃), with a storage period of not less than 3 months, providing a clear basis for the product's shelf life.
Standard Implementation Recommendations and Industry Impact
Implementation Recommendations for Manufacturing Enterprises
- Raw Material System Construction:Immediately establish a raw material traceability system, recording information throughout the entire process of procurement, transportation, and processing in accordance with the requirements of 5.3. Prioritize cooperation with energy forest bases that meet sustainability requirements.
- Testing Capacity Building:Equip necessary testing equipment, such as a closed-cup flash point analyzer, kinematic viscometer, and gas chromatograph, according to the test methods in Tables 1-6. Consider cooperating with third-party testing institutions to ensure the authority of test results.
- Process Optimization Direction:Improve processes targeting key indicators in the standard. For example, ester fuel producers need to optimize transesterification and refining processes, increasing the fatty acid methyl ester content from 96.0% to ≥96.5%, and controlling the total glycerol content to ≤0.240%. Carbon Footprint Management: Conduct full life-cycle carbon footprint accounting as early as possible, establish a carbon emission database, and prepare for future participation in carbon trading and obtaining green certification. Implementation Recommendations for Regulatory Agencies: Standards Dissemination and Training: Organize a series of training sessions for producers, testing institutions, and users, focusing on interpreting the classification system, technical indicators, and testing requirements. Standardized Testing Methods: Coordinate with all testing institutions to strictly operate according to the 42 methods referenced in the standard, ensuring the consistency and comparability of test results. Market Access Integration: Use this standard as the technical basis for the certification and market access of forestry biomass liquid fuel products, promoting the formation of a standardized market.
Industry Impact and Outlook
The implementation of LY/T 3451—2025 will have multi-dimensional industry impacts:
1. Promoting efficient resource utilization: The standard clarifies the legality of forestry residues as raw materials, which will promote the energy utilization of approximately 350 million tons of forestry residues annually, creating new economic value.
2. Guiding technological upgrading: The refined indicator requirements will force enterprises to carry out technological transformation. For example, the C15~C18 alkane content requirements for hydrocarbon fuels will promote the application of second-generation biodiesel technologies such as hydrodeoxygenation (HDO) and hydrocracking.
3. Expanding application scenarios: The clear classification and indicator settings of the six types of fuels provide matching products for different application scenarios. Ether fuels, as additives and blended fuels, will be developed in niche markets such as industrial kilns.
4. Alignment with International Standards: The standards are aligned with international standards in key indicators such as sulfur content and oxidation stability, which is conducive to my country's participation in international market competition for forestry biomass liquid fuels and serves the "Belt and Road" green energy cooperation. 5. Supporting Policy Formulation: The standard provides technical support for policies such as fiscal subsidies, tax incentives, and green procurement, contributing to a virtuous cycle of "standard-led development - industry growth - policy support."Forward-looking Recommendations:
It is recommended to initiate revision research 2-3 years after the standard's implementation, focusing on: 1) adding specific technical requirements for aviation biofuels (SAF); 2) supplementing emerging product categories such as bio-based naphtha and bio-based lubricating oil base oils; 3) introducing rapid testing methods to meet on-site regulatory needs; and 4) further aligning with the sustainability requirements of international regulations such as EU RED II and US RFS.
LY/T 3451—2025, as my country's first comprehensive product standard for forestry biomass liquid fuels, was released and implemented at a critical juncture in the energy transition. The standard not only provides specific technical specifications but also conveys the core concepts of sustainable development, full life-cycle management, and high-quality development.
With the implementation of the standards, my country's forestry biomass energy industry will upgrade from "having products" to "having high-quality products," playing a more important role in ensuring energy security, promoting rural revitalization, and achieving "dual carbon" goals.