Anaerobic digesters and biogas
Anaerobic digester electrician for Northern Colorado
Digester plants combine continuous process equipment, gas handling, classified areas, and vendor skids that each arrive with their own controls. Very few electrical contractors in Northern Colorado have worked on them. A good share of our time in the trade has been spent on exactly that.
The work
Power and controls for the whole process
A digester has to keep mixing, heating, and moving gas around the clock. The electrical work behind it has to be built for continuous duty, a corrosive atmosphere, and the hazardous-location rules that apply around biogas.
Scope
From feed pumps to the gas train
We wire and service mixers, feed and recirculation pumps, separators, and augers, and the power and controls for gas handling equipment: blowers, conditioning and treatment skids, flares, and upgrading equipment. On sites with an engine-generator or CHP unit, we handle the wiring at the equipment: power and control connections between the generator package, its controls, and the plant. The utility interconnection and its protection are designed by the utility and the engineer of record, and we build to their drawings.
The same classified-area methods carry over to oil and gas facilities, a newer area of work for us that we are growing into deliberately.
- Mixer, pump, and auger circuits
- Gas handling and blower controls
- Flare and upgrading skid hookups
- Generator and CHP equipment wiring
- Classified-area wiring methods
- Process instrumentation and loop checks
- Heat trace and freeze protection
- PLC and control panel integration
What goes wrong
Common digester electrical problems
Digester sites are hard on equipment, and mistakes in classified areas are not just a maintenance problem. These are the issues we see most.
Seals and classified-area mistakes
Areas around gas handling equipment, digester covers, and gas piping can be classified locations under the NEC. Missing or unpoured conduit seals and equipment not suited to the location are common findings, and they need to be corrected, not worked around.
Corrosion from biogas
Hydrogen sulfide in biogas attacks copper and electrical terminations. Enclosure selection, placement, and sealing all matter, and corroded terminations get replaced rather than cleaned and reused.
Mixer and pump motor failures
Mixers and pumps run continuously against heavy, abrasive material. Correct protection, sound connections, and drives set for the load help them last, and a failure gets traced to its cause.
Heat trace failures in winter
A Northern Colorado winter finds every heat trace circuit that has failed. Testing before the cold arrives is cheaper than thawing lines afterward.
Vendor skids that do not agree
Each equipment vendor brings its own panel, wiring practices, and documentation. Tying them together cleanly, and documenting the result, prevents finger-pointing when something stops.
Process
What to expect when you call
A digester cannot simply be turned off, so most of the job is planning with your operators.
- Tell us the scope. Drawings, vendor documentation, and a description of the problem or the change you need.
- Site walk with the operator. We review the equipment, the area classification drawings, and your site safety procedures before quoting.
- Straight quote. Scope, lead times, and what each step means for the process.
- Work coordinated with operations. Shutdowns are planned with your operators, and work around gas equipment follows your site's procedures.
- Documentation. Updated drawings, labels, and a record of what was installed and checked.
Questions
Digester electrical questions, answered plainly
Who determines the hazardous area classification?
The classification comes from the facility's engineer or area classification drawings. Our job is to install to it under the NEC: the right wiring methods, equipment suited to the location, and properly installed seals. If something on site does not match the drawings, we raise it before we build.
Do you wire generator and CHP equipment?
Yes, at the equipment level: power and control wiring between the generator package, its controls, and the plant. The utility interconnection and its protection are designed by the utility and the engineer of record, and we build to their drawings.
Can you work on a digester that is operating?
Yes, with planning. We coordinate with your operators on which equipment can be isolated and when, and follow your site's safety procedures for work near gas equipment.
Do you work with equipment vendors' skids?
Yes. We land power and controls to vendor skids, tie them into plant controls, and document how everything connects so the plant has one accurate set of drawings.
Do you also do oil and gas work?
Yes, on a smaller scale. It is a newer area for us. The classified-area and process-control methods carry over from digester work, and we will tell you plainly where our experience ends.
Related
Related work
Digester work draws on the drives, motor control centers, and controls covered on our services page. Many digesters sit alongside dairies, which are covered on the industries page.
Start a project
Planning digester work?
Send drawings, vendor documentation, or a description of the problem. We will get back to you the same business day with a straight answer.