Background
Biogas cleaning plants offer a viable solution for purifying biogas to biomethane. Through this process, biomethane is separated from Carbon Dioxide and hydrogen sulphide before being dried, subsequently ready as vehicle fuel or for gas networks.
Unfortunately, biofouling in scrubber towers impacts efficiency, requiring regular caustic cleaning to restore optimal performance levels. In some instances, deep cleaning every 8 weeks is necessary as part of a routine maintenance programme.
The Challenge
A water wash plant producing 900m³ per hour of bio-methane at an Anaerobic Digestion site was experiencing loss of performance after just six weeks of operation.
Performance Decline
Decline began two weeks prior to scheduled cleaning, with 25% of production lost by cleaning time.
Operational Impact
24 hours required to restore gas scrubber performance after each caustic cleaning procedure.
The caustic cleaning process uses large quantities of chemicals which are inefficient, potentially hazardous, and lead to significant interruption of biogas plant operations.
The Solution
ChloroKlean Plus, a unique biocidal agent specifically engineered for treatment of water wash columns, was trialled with the aim of eliminating bacteria and destroying biofilms.
The goal was to increase the time between caustic cleaning cycles and reduce operational inefficiencies caused by biofouling.
The Results
The result of the trial was exceptional. The facility was able to extend time between caustic cleans from six weeks to four months - a 167% improvement. During the trial, no adverse impact on gas quality was observed.
| Cost Item | Previous Method | With ChloroKlean Plus |
|---|---|---|
| Cleans per Year | 8.7 | 3 |
| Cleaning & Chemicals | £164,667 | £57,000 |
| Lost Production | £602,082 | £208,413 |
| ChloroKlean Plus | - | £150,180 |
| Total Annual Cost | £844,437 | £442,485 |
Annual Saving: £401,951.67
Key Benefits Achieved
Extended Clean Intervals
Cleaning interval extended from 6 weeks to 4 months, reducing operational disruption by 65%.
£401k Annual Saving
Total annual cost reduction of over £400,000 through reduced cleaning, chemicals, and lost production.
No Quality Impact
No adverse impact on gas quality was observed during or after the trial period.
Conclusion
Following the successful trial, the facility adopted ChloroKlean Plus as the ideal solution to biofouling in their water wash plant. The treatment has proven to be both cost-effective and operationally beneficial, delivering:
- 47.6% reduction in total operational costs
- Significantly reduced chemical usage and handling
- Extended operational periods between maintenance
- Maintained gas quality throughout treatment