The stable operation of the endothermic gas generator relies on three types of maintenance: daily inspections (temperature, pressure, dew point/carbon potential, flow rate, alarm), regular carbon burnout (removing carbon deposits in the catalyst and reaction tank and restoring activity), and periodic component inspections (catalyst, reaction tank, cooler, mixing pump, valves and sensors). Dew point drift, rising residual methane, and falling outlet pressure are often early signs that maintenance is needed.
- Daily: temperature, pressure, dew point/carbon potential, gas production, alarm records
- Burn carbon regularly: remove carbon deposits and restore catalyst activity
- Periodic inspection: catalyst, reaction tank, cooler, mixing pump, valves, sensors
- Early signs: dew point drift, CH₄ increase, pressure differential increase, carbon black
- Maintaining records is important evidence for CQI-9 audits
Why does carbon deposit occur?
When the generator has a low air-fuel ratio, insufficient temperature, or drastic load changes, the cracking reaction may be incomplete, and free carbon will be deposited on the catalyst surface and the inner wall of the reaction tank. Carbon Deposits Association:
- Covering the active sites of the catalyst increases residual CH₄;
- Increase air flow resistance and reduce gas production and outlet pressure;
- Making dew point control difficult.
Burn-out
Charcoal burning is to pass an appropriate amount of air into the reaction tank according to regulations after stopping gas production, and oxidize the coke into CO₂ under controlled temperature and discharge it.
Key points:
- Strictly follow the equipment operating procedures, control the air volume, and prevent local overtemperature damage to the reaction tank and catalyst;
- Charcoal burning frequency depends on operating conditions and can be determined based on CH₄, dew point and differential pressure trends, rather than mechanically fixed cycles;
- Gas cannot be supplied during charcoal burning. If continuous production is required, double furnaces can be used, one in use and one in standby, to burn charcoal in turn.
Daily inspection list
| Project | Check content |
|---|---|
| Reaction tank temperature | Whether it is within the set range and whether each area is balanced |
| Gas production and pressure | Are the outlet pressure and flow rate of each furnace branch normal? |
| Dew point / carbon potential | Is it stable and does it need frequent adjustments? |
| gas, air pressure | Is it within the interlocking range? |
| cooler | Outlet temperature, cooling water flow (water-cooled type) |
| Alarm record | Are there any unhandled alarms? |
| safety facilities | Flame detection, igniter, pressure relief and venting ignition |
Periodic inspection
- catalyst: Screening needs to be supplemented or replaced when activity decreases, powders or agglomerates;
- reaction tank: Check for deformation, cracks and oxidation thinning;
- cooler: Clean carbon deposits and scale;
- Mixing pumps and valves: Check for wear and leaks;
- sensor: Calibration and replacement of oxygen probes, dew point sensors, and thermocouples.
Fault symptoms and troubleshooting sequence
- Let’s look at measurement first: Whether the sampling pipeline is leaking and whether the sensor is aging;
- Look at the ratio again: Gas pressure, air flow, proportional valve status;
- Look at the reaction again: Reaction tank temperature, catalyst carbon deposit;
- Finally, look at cooling and transportation: Cooler, pipeline carbon deposits and condensed water.
Frequently asked questions
How often should you do charcoal burning?
There is no uniform cycle. Continuously record the residual CH₄, dew point adjustment amount and pressure difference, and arrange charcoal burning when they show trend changes, which is more scientific than a fixed period.
How often should the catalyst be replaced?
Depends on operating temperature, load, charcoal quality and raw gas quality. If the residual CH₄ is still high after carbon burnout and the gas production capacity cannot be restored, the catalyst usually needs to be checked and replaced.
Can maintenance be outsourced?
Can. The service section of Gosi Control's official website provides generator maintenance services; when outsourcing, maintenance records and test data should be provided upon request for inclusion in quality system documents.