Comprehensive Introduction to Yipu CNG Station Natural Gas Dehydration Unit

Overview

Yipu CNG Station Natural Gas Dehydration Unit is a key purification equipment ensuring the safe, efficient, and economical operation of CNG refueling stations. Through deep dehydration technology, it fundamentally solves the core problems plaguing station operations—ice blockage, corrosion, and failure to meet gas quality standards. Its high automation, reliable skid-mounted design, and excellent performance indicators make it an ideal choice for new station construction or old station renovation, creating long-term, stable value for CNG station operators.

I. Market Pain Points

• Corrosion and Damage to Key Equipment: Natural gas without deep dehydration undergoes multiple compression, storage, and decompression processes at CNG stations, causing moisture to condense and accumulate. This leads to electrochemical corrosion of core equipment such as on-site compression units, gas storage cylinders (wells), high-pressure pipelines, and gas dispensers, triggering leaks, seal failures, and even safety accidents with extremely high maintenance costs.
• Gas Dispenser Ice Blockage and Measurement Inaccuracy: During the instant gas refueling process for vehicles, the rapid decompression and heat absorption of natural gas cause a sudden temperature drop, freezing residual moisture and clogging precision valves and nozzles of gas dispensers (i.e., “ice blockage”), resulting in interrupted refueling. Meanwhile, moisture affects the measurement accuracy of flow meters, leading to trade losses.
• Vehicle Engine Failures and Safety Hazards: CNG containing moisture entering the vehicle fuel system will corrode high-pressure fuel pipelines and injectors. When combined with sulfides in the gas, it also corrodes engine cylinders and spark plugs, resulting in reduced power, stalling, and increased maintenance frequency, seriously affecting user confidence and the station’s reputation.
• High Operation and Maintenance Costs: Non-automated drying equipment requires dedicated personnel on duty and frequent maintenance, increasing the station’s labor costs. Unstable dehydration effects can cause unplanned shutdowns, impacting the station’s normal operation and revenue.
• Failure to Meet Gas Quality Standards: National standards for Compressed Natural Gas (CNG) for Vehicle Use (GB 18047) impose strict requirements on water dew point (at the maximum operating pressure, the water dew point shall not be higher than -13℃; for deep dehydration, lower requirements are usually specified). Non-compliance will result in penalties from quality inspection authorities.

II. Unit Process

Designed specifically for the continuous and efficient operation needs of CNG stations, the process is as follows:

1. Inlet Gas Pretreatment: Pipeline natural gas from urban gas networks or front-end pressure regulation (inlet temperature ≤40℃) first enters a filter to remove solid particles and free liquid water, protecting subsequent adsorbents.
2. Adsorption Deep Dehydration: The pretreated gas enters a molecular sieve tower in the adsorption state (e.g., Tower A). The 3A/4A molecular sieve filled in the tower efficiently and selectively adsorbs water molecules.
3. Clean Dry Gas Output: The deeply dehydrated dry gas has an atmospheric dew point of -55℃ ~ -70℃, far exceeding national standards. This dry gas is divided into two paths:
   • Main Path: Transported to the CNG compression unit for pressurization and filling.
   • Branch Path: A small amount of gas is used as the gas source for regeneration.
4. Regeneration and Cooling:
   • Switching: When the adsorbent in Tower A is nearly saturated, the system automatically switches to Tower B for adsorption without disturbance, ensuring continuous gas supply.
   • Heating Regeneration: The dry gas from the branch path is heated to 150~180℃ by an electric heater and then blown back into Tower A to desorb the moisture trapped in the molecular sieve.
   • Cooling: After the completion of heating regeneration, switch to normal-temperature dry gas to cool the adsorption tower, preparing for the next adsorption cycle.
5. Intelligent Fully Automatic Control: The entire “adsorption-regeneration-cooling” cycle is fully controlled by a PLC system without manual intervention. Regenerated waste gas is usually discharged to a vent pipe or a safe area.

III. Working Principle

The core working principle is “Temperature Swing Adsorption (TSA)”.

• Adsorption Process: At ambient temperature and system pressure, 3A/4A molecular sieve has a strong affinity for polar water molecules due to its uniform microporous structure (pore size 3-4Å) inside the crystals. It can firmly adsorb water molecules in the pore channels while allowing gas molecules such as methane to pass through, thereby achieving deep dehydration.
• Regeneration Process: The adsorption capacity of the adsorbent decreases with increasing temperature. Through low-temperature regeneration technology, a small amount of product gas is heated and then backblown through the adsorption tower to provide energy for the adsorbed water molecules, enabling them to desorb, thereby restoring the drying capacity of the molecular sieve for cyclic use.

IV. Core Advantages

• Ultra-Low Dew Point with Comprehensive Protection: The outlet atmospheric dew point is ≤-55℃ ~ -70℃, which can completely eliminate the risk of ice blockage and corrosion at CNG stations and vehicle terminals, providing the highest level of protection for core equipment and end users.
• High Efficiency, Energy Saving, and Reduced Losses: Adopts closed-loop regeneration technology. The regeneration gas is its own product gas, and the dosage is optimized through design, resulting in an extremely low gas loss rate (usually <5%), directly reducing operating costs.
• Fully Automatic Operation with Unattended Capability: The PLC control system realizes one-key start-stop, fully automatic cycle switching, and fault alarm. Station staff can operate it without professional knowledge, greatly saving labor and being suitable for 24/7 operating stations.
• Skid-Mounted Integration for Quick Installation: The equipment is manufactured, tested, and pre-assembled in the factory, then transported to the site as an integrated skid. It can be put into operation only by connecting external pipelines and power supplies, significantly shortening the installation cycle and reducing on-site construction costs.
• Safe, Reliable, and Fully Certified: The overall explosion-proof grade reaches Exd Ⅱ BT4, and the protection grade is IP54/IP65, ensuring safe and stable operation in the flammable and explosive environment of CNG stations. Provides mechanical test reports and supports video factory inspection, with guaranteed quality.

V. Technical Strength

• Strong Targeted Design: Specifically designed for CNG station working conditions, it has good adaptability to fluctuations in inlet pressure and flow, ensuring stable output of qualified dry gas even when the compressor operates intermittently.
• Wide Processing Capacity Range: The working flow covers 500~20,000 Nm³/h, meeting the needs of different scales from standard stations to large mother stations.
• Optimization of Core Components: Optimizes and matches core components such as circulating compressors, electric heaters, and program-controlled valves to ensure the reliability and economy of long-term system operation.
• Intelligent Operation and Maintenance Support: The control system is equipped with remote monitoring functions, which can upload operating data to the cloud or central control room, realizing predictive maintenance and remote fault diagnosis.

VI. Product Introduction

• Product Name: Yipu Skid-Mounted CNG Station Natural Gas Dehydration Unit
• Brand: Yipu
• Design Standard: Strictly designed in accordance with the national standard for Compressed Natural Gas (CNG) for Vehicle Use (GB 18047).
• Working Method: Dual-tower alternation, continuous cycle operation.
• Control Method: PLC programmable controller, digital temperature control instrument, automatic fault alarm.
• Appearance and Structure: Compact skid-mounted design with flexible dimensions (L: 2500~8000mm) and weight of 2000-7000kg, saving valuable space in the station.

VII. Application Scenarios

• CNG Mother Stations: Provides deeply dehydrated natural gas for CNG transportation tank trucks, ensuring no liquid water precipitation during transportation and transfer, and protecting tank trucks and sub-station equipment.
• CNG Standard Stations: Directly connects to pipeline natural gas, performs purification treatment, and supplies it to on-site compressors and gas storage systems, serving as the core pretreatment equipment of standard stations.
• CNG Sub-Stations: In sub-stations using hydraulic boosting or compressor boosting, deeply dehydrates the incoming gas to protect boosting equipment and gas dispensers.
• L-CNG Refueling Stations: Serves as a post-treatment unit for vaporized LNG, deeply dehydrates the reheated natural gas, and then prepares CNG through high-pressure pumps and vaporizers, ensuring the final product gas meets dew point requirements.

VIII. Technical Indicators

Parameter Item	Technical Indicator / Description
Product Category	CNG Station Natural Gas Dehydration System
Working Medium	Natural gas (as well as oilfield associated gas, shale gas, etc.)
Treatment Flow	500 ~ 20,000 Nm³/h
Working/Design Pressure	0.1 ~ 8.0 MPa / 1.0 ~ 9.0 MPa
Inlet Condition	At 0.6MPa, dew point -13℃ (saturated with water)
Outlet Atmospheric Dew Point	≤ -55℃ ~ -70℃ (far exceeding national standards)
Adsorbent	3A / 4A molecular sieve
Regeneration Method/Temperature	Low-temperature regeneration / 150 ~ 180℃
Power Supply and Power	380V / 50Hz / 12.30 ~ 150 kW
System Pressure Drop	≤ 50 kPa (effectively ensuring the intake pressure of the downstream compressor)
Noise	≤ 85 dB
Protection/Explosion-Proof Rating	IP54 or IP65 / Exd Ⅱ BT4
Core Advantages	Stable and efficient equipment, fully automatic operation, energy saving and environmental protection, remote maintenance

Technical Parameter Table of CNG Station Natural Gas Dehydration Unit

Item	Parameter	Item	Parameter
Product Category	CNG Station Natural Gas Dehydration Unit	Working Medium	Oilfield associated gas, shale gas, natural gas, coalbed methane, biogas
Brand	Yipu	Place of Origin	Zhejiang, China
Working Flow	500~20,000 Nm³/h	Core Components	Motor, compressor, adsorption tower, molecular sieve, filter, booster, cooler, separator, heater, control valve and control system
Core Advantages	Stable and efficient equipment, fully automatic operation, energy-saving and environmentally friendly, remote maintenance	Application Industries	CNG mother stations and refueling stations; urban gas and industrial fuel sector; power generation industry; chemical and fertilizer industry
Mechanical Test Report	Available	Video Factory Inspection	Available
Working Pressure	0.1~8.0 MPa	Inlet Temperature	0~40℃ (50℃)
Inlet Pressure Dew Point	0.6 MPa/-13℃/saturated with water	Single-Tower Continuous Working Time	12~48 h
System Design Pressure	1.0~9.0 MPa	Regeneration Time	≤8 h (10 h)
Adsorbent	3A/4A molecular sieve	Outlet Atmospheric Dew Point	≤-55℃~-70℃
Regeneration Cooling Method	Air cooling/Water cooling	Outlet Filtration Precision	≤3 μm
Power Supply/Power	380V/50Hz/12.30~150 kW	Protection Grade	IP54 or IP65
Import and Export Pressure Drop	≤50 kPa	Motor Explosion-Proof Grade	ExdⅡ BT4
Noise	≤85 dB	Regeneration Gas Heating Temperature	150~180℃
Overall Dimensions	L: (2500~8,000) mmW: (1600~3,000) mmH: (2350~2,850) mm	Equipment Weight	2000-7000 kg
		Import and Export Pipe Diameter	DN50~DN200
Working Method	Dual-tower/multi-tower alternating “adsorption-regeneration” for continuous gas supply	Regeneration Method	Closed/open cycle, pressure reduction/isobaric regeneration/heating regeneration
Control Method	PLC programmable controller, digital temperature control instrument, automatic fault alarm	Switching Method	Manual/Automatic

Packaging, Shipping Information and Quotation

Item	Details
Sales Unit	Single product/set
Single Package Dimension	250020002850 (LWH) mm
Single Product Gross Weight	3000 kg
Packaging Method	Wooden case/three-proof cloth (waterproof, mildew-proof, corrosion-resistant)
Quotation	$28,000 ~ $100,000