How Is CBG Stored After Compression?
After compression, compressed biomethane (CBG) is stored in cascade pressure banks, split into low, medium, and high-pressure steel vessels that fill vehicles efficiently, or loaded into tube trailers for transport to off-site dispensers. Cascade storage lets a dispenser draw from the bank that best matches the vehicle tank pressure, while tube trailers decouple production from distant refueling sites.
Cascade Storage Logic
A single buffer at 250 bar wastes energy refilling a near-empty vehicle tank. Splitting storage into low, medium, and high banks lets each fill start from the closest pressure and finish from the high bank, speeding dispensing and smoothing compressor load.
Design Parameter Table
| Parameter | Typical value or range | Why it matters |
| Storage pressure | 200-250 bar | Matches vehicle CBG |
| Bank split | Low / medium / high | Efficient cascaded fill |
| Vessel type | Steel pressure vessels | ASME / PED rated |
| Transport | Tube trailers | Move gas off-site |
| Buffer need | Hours to days of output | Decouples production |
| Limitation to check | Thermal expansion | Allow for sun/heat |
Storage Options Compared
| Option | Best for | Note |
| Cascade banks | On-site dispensing | Fast, efficient fills |
| Single buffer | Small, steady use | Simpler, less efficient |
| Tube trailer | Off-site transport | Mobile high-pressure |
Project Case Study
Zhenyuan Group Biogas Project, Henan. The vehicle-grade methane plant produces 3 million m³ of CH₄ per year from 650 tonnes per day of manure and washing wastewater; such a fuel-grade output requires compressed storage and filling infrastructure so the gas can be dispatched to vehicles rather than flared.
| Project | Zhenyuan Group Biogas Project, Henan |
| Location | Xinzheng, Henan, China |
| Industry | Agriculture / Renewable Fuel |
| Application | Vehicle-grade methane production |
| Product | CSTR Ø15.29 × 15 m primary, Ø5.22 × 6 m secondary |
| Result | 3,000,000 m³ vehicle-grade CH₄ per year |
| Status | Delivered 2013 |
About Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel)
Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel) supplies the product technology for CBG storage through its pressure-vessel manufacturing capability (I/II class license, ASME and ISO 9001 discipline), relevant to the cascade banks and buffer vessels of a biomethane skid. The upstream GFS digester tanks and the downstream steel pressure vessels are engineered as one fuel system.
Store CBG in cascade steel banks at 200-250 bar for efficient dispensing, or in tube trailers to move it off-site. Send your daily output and fill pattern and we will size the banks and vessels.
Frequently Asked Questions (FAQ)
Q1: How is compressed biomethane stored?
A: In cascade banks of low, medium, and high-pressure steel vessels, or in tube trailers for transport.
Q2: What is cascade storage?
A: Splitting storage into pressure tiers so a vehicle fills from the closest bank first, then the high bank, saving energy and time.
Q3: Are tube trailers used for CBG?
A: Yes, to carry compressed biomethane from a production site to a distant dispenser.
Q4: What vessels hold CBG at 250 bar?
A: Steel pressure vessels rated to ASME, PED, or equivalent codes for 200-250 bar service.
Q5: Why not one big buffer?
A: A single buffer is simpler but refills vehicles inefficiently; cascade banks match pressure and speed fills.
Q6: How much buffer is needed?
A: Enough for hours to days of output so production and dispensing are decoupled.
Suggested CTA
Send your CBG output and dispensing pattern. We will size the cascade banks and pressure vessels for your site.