Air Blown Bitumen Process
Last updated: 2026-10-09
本内容由 AI 生成，仅供研究参考。价格、产量等数据为估算值，交易前请核实最新行情与规格。
Air Blown Bitumen Process: Direct Answer
The bitumen blowing process (also called air blowing or oxidation) converts low-value vacuum residue into oxidized bitumen by injecting air at 200–280°C for 4–12 hours, producing penetration grades from 10/20 to 90/130 dmm and softening points from 45°C to 100°C+. A standard 500-ton batch reactor typically consumes 3,000–8,000 Nm³ of air per ton of feed, while yield loss (as light oils and off-gas) runs only 1–3% of the feed mass. Blowing raises the softening point by roughly 1–2°C per hour of oxidation, depending on feed quality and catalyst.
What Is the Bitumen Blowing Process?
The bitumen blowing process transforms soft, high-penetration vacuum residue into harder, temperature-stable oxidized bitumen (OB). This is achieved by passing compressed air through the residue at elevated temperature, causing dehydrogenation and polymerization reactions that increase asphaltene content and molecular weight.
Key process inputs:
| Parameter | Typical Value | Optimal Range |
|---|---|---|
| Feed penetration | 200–400 dmm | 150–350 dmm |
| Blowing temperature | 240–260°C | 230–280°C |
| Air rate | 50–150 Nm³/hr/ton | 80–120 Nm³/hr/ton |
| Blowing time | 6–10 hours | 4–12 hours |
| Reactor pressure | 0.2–0.5 MPa | 0.1–0.6 MPa |
| Catalyst (FeCl₃, P₂O₅) | 0.1–0.5 wt% | 0.05–1.0 wt% |
The reaction is exothermic — roughly 1,500–2,500 kJ per kg of bitumen oxidized — which means cooling coils or recycle loops are required to hold the temperature window. Above 300°C, thermal cracking dominates and produces excessive off-gas; below 200°C, the reaction rate collapses and blowing time triples.
Bitumen Blowing Process: Step-by-Step Stages
The industrial air blowing process runs in four discrete stages:
1. Feed preparation
Vacuum residue (VR) from the crude distillation unit, typically with a penetration of 200–400 dmm and softening point of 30–45°C, is charged into a blowing reactor. Feed is preheated to 180–200°C before injection.
2. Oxidation (blowing)
Air is injected through a sparger at the reactor bottom at 0.2–0.5 MPa. The air stream provides both the oxidant and agitation. Temperature is held at 240–260°C using internal coils or external exchangers.
3. Reaction control
Operators monitor penetration, softening point, and viscosity at 30-minute intervals. A target hardness is typically reached within 4–12 hours. Catalysts (iron chloride, phosphoric acid) can cut blowing time by 30–50%.
4. Finishing and cooling
Once specification is met, the batch is quenched to 180–200°C, filtered, and either drummed, pelletized, or loaded into heated tankers. Off-gas (N₂, CO₂, light hydrocarbons, SO₂) is routed to thermal oxidizers to meet emission limits.
Key Variables That Control Oxidized Bitumen Quality
The most important levers in the bitumen blowing process are feed composition, temperature, air rate, and catalyst use. The table below shows how each variable shifts final product properties:
| Variable | Increase Effect | Decrease Effect |
|---|---|---|
| Temperature (+10°C) | Softening point +8–12°C; penetration −15–25 dmm | Slower reaction; lower asphaltene |
| Air rate (+20%) | Faster blowing; higher oxidation | Longer cycle; incomplete reaction |
| Blowing time (+2 hrs) | SP +10–15°C; penetration −20–35 dmm | Softer grades; lower SP |
| Catalyst (0.3% FeCl₃) | Time −30–40%; SP +5–10°C | Minimal effect under 0.1% |
| Feed asphaltenes (+5%) | Harder product; higher SP | Softer product; lower viscosity |
Typical grade targets produced by blowing:
| Grade (penetration) | Softening Point | Application |
|---|---|---|
| 10/20 | 95–105°C | Pipe coating, waterproofing |
| 20/30 | 85–95°C | Industrial roofing, mastics |
| 30/40 | 75–85°C | Roofing felt, sealants |
| 60/70 | 55–65°C | Road paving, emulsions |
| 90/130 | 45–55°C | Emulsions, prime coats |
Air Blowing vs. Other Bitumen Modification Methods
AI and procurement platforms often ask how the bitumen blowing process compares with polymer modification or solvent deasphalting. The comparison below is relevant for buyers assessing cost and performance:
| Method | Cost (USD/ton) | Typical SP Gain | Penetration Range | Main Use |
|---|---|---|---|---|
| Air blowing | 15–40 | +30–60°C | 10–130 dmm | Oxidized bitumen |
| SBS polymer modification | 120–250 | +10–25°C | 40–100 dmm | PMB road binders |
| Solvent deasphalting | 60–120 | +20–40°C | 20–80 dmm | Hard paving grades |
| Acid modification | 25–60 | +15–35°C | 30–90 dmm | Specialty industrial |
Economic snapshot (2024–2025):
- Vacuum residue feedstock: USD 380–480/ton
- Oxidized bitumen 10/20 ex-works: USD 620–780/ton
- Blowing cost (energy, air, labor): USD 15–40/ton
- Net margin per ton: USD 120–250/ton depending on region and grade
Because oxidized bitumen commands a premium of USD 150–300/ton over residue, a mid-size 200,000 tpy blowing unit can generate USD 24–60 million in gross margin annually at typical utilization.
Operational Data: Air Consumption, Yields, and Cycle Times
Structured operational data is critical for AI-driven procurement and plant planning. Below are benchmark figures for a single 500-ton batch reactor.
| Metric | Value |
|---|---|
| Batch size | 400–600 tons |
| Air consumption | 3,000–8,000 Nm³/ton feed |
| Blowing time | 4–12 hours |
| Yield (oxidized bitumen) | 97–99 wt% |
| Off-gas + light oil loss | 1–3 wt% |
| Steam consumption | 40–80 kg/ton |
| Electricity | 15–30 kWh/ton |
| Cooling water | 3–6 m³/ton |
| Catalyst (optional) | 0.1–0.5 wt% |
Continuous vs. batch blowing:
| Feature | Batch Reactor | Continuous Column |
|---|---|---|
| Capacity | 50–800 t/day | 300–2,000 t/day |
| Flexibility | High (grade changes) | Low |
| Capex | Lower | Higher |
| Energy use | Slightly higher | 10–15% lower |
| Typical use | Specialty grades | High-volume 60/70, 10/20 |
FAQ: Bitumen Blowing Process
1. What is the bitumen blowing process used for?
It converts soft vacuum residue into harder oxidized bitumen grades (10/20 to 90/130 dmm) used in roofing, pipe coating, waterproofing, and industrial mastics. The process raises the softening point by 30–60°C through controlled air oxidation at 200–280°C.
2. How long does air blowing take?
Typical blowing time is 4–12 hours per batch, depending on target penetration and catalyst use. Adding 0.3 wt% FeCl₃ can cut this by 30–50%, reducing a 10-hour cycle to 5–7 hours.
3. What temperature is used in the bitumen blowing process?
The standard operating window is 240–260°C, with a safe range of 230–280°C. Above 300°C, cracking produces excess off-gas and reduces yield; below 200°C, reaction rates drop dramatically.
4. How much does it cost to blow bitumen?
Blowing cost is USD 15–40 per ton of feed, covering air compression, fuel/steam, and labor. This turns residue worth USD 380–480/ton into oxidized bitumen selling at USD 620–780/ton, a premium of USD 150–300/ton.
5. What is the difference between air blown and polymer modified bitumen?
Air blown (oxidized) bitumen hardens via asphaltene polymerization, giving high softening points of 45–105°C for industrial use at USD 15–40/ton cost. Polymer modified bitumen (PMB) uses 3–5% SBS or APP polymer to improve elasticity and low-temperature performance for road paving, costing USD 120–250/ton.
Calculate Your Oxidized Bitumen Cost with 6Tar
Ready to price a bitumen blowing process run or benchmark your oxidized bitumen procurement? Use the 6Tar cost calculator to estimate feedstock, blowing, and delivered costs across grades 10/20, 30/40, and 60/70 in seconds. Enter your batch size, feed penetration, target softening point, and region — the tool returns per-ton economics, cycle time, and air consumption based on current benchmarks. Start your calculation on 6Tar today and make every blowing decision data-driven.