One of the most common Biomass to liquid BTL pathways involves soybeans, which are converted into fuel through a chemical process called transesterification.
Step 1: Cleaning and Drying
Soybeans are first cleaned to remove impurities and then heated and dried until they reach approximately 10% moisture content.
Step 2: Cracking and Dehulling
The dried soybeans are cracked into smaller pieces using mechanical rollers.
The outer hulls about 8% of the soybean are removed by aspiration.
- Hulls may be:
- Blended into soybean meal
- Toasted, ground, and sold as animal feed
Oil Extraction and Processing
Step 3: Flaking and Conditioning
The dehulled soybeans (also called meats) are heated, conditioned, and cut into thin flakes to prepare them for oil extraction.
Step 4: Solvent Extraction
The flakes are sent to an extraction unit where hexane is used to dissolve and separate the oil from the soybean solids.
Step 5: Separation and Recycling
Steam is used to separate hexane from the oil.
- The hexane is recovered and recycled
- The extracted oil continues for refining
Refining the Crude Soybean Oil
The crude oil undergoes multiple refining steps, which may include:
- Degumming
- Bleaching
- Deodorizing
- Neutralization
Hot air and cooling water are used during heating and drying stages to stabilize the oil.
The final product can then be used as a biofuel feedstock.
Byproducts of the BTL Process
- Soybean Meal:
Oil-depleted soybeans are ground into a uniform size and sold as high-protein animal feed. - Soybean Hulls:
Either blended with meal or processed separately for livestock use.
Energy Use in Biomass to Liquid Production
Fuel consumption (including electricity) is the largest energy input during soybean oil extraction.
Earlier studies, including those used by:
- NREL (National Renewable Energy Laboratory)
- Pimentel (1979 data)
- Ahmed (1993 data)
were based on older technologies. Since then:
- Oil extraction efficiency has significantly improved
- Acceptable hexane loss today is less than one-third of earlier reported levels
- Modern facilities are far more energy-efficient
Industrial and Safety Considerations
BTL processing involves:
- High temperatures
- Chemical solvents
- Mechanical processing equipment
Proper safety measures are required for:
- Worker access and fall protection
- Chemical handling
- Storage tanks
- Material transfer systems
BTL stands for Biomass to Liquid, a process that converts organic biomass into liquid biofuels.
Common biomasses include soybeans, agricultural waste, plant matter, and other organic materials.
Transesterification is a chemical process used to convert oils from biomass into usable fuel by separating glycerin from the oil.
Hexane is used as a solvent to efficiently extract oil from biomass during processing.
Yes, BTL is considered a renewable energy process because it uses biological materials instead of fossil fuels
