Trash to treasure: From dairy waste to renewable natural gas distributed as fuel

Operating since 2011, Meridiam’s biogas facility in Idaho has used dairy cow manure to produce clean, renewable electricity delivered to the electric grid. The company set out to expand the digestion capacity and transform the plant from electric power to RNG, taking feedstock to the next level, capturing the gas, and reducing greenhouse gas emissions generated by the combustion of raw biogas in the generators.

The purpose of the endeavor is to reduce greenhouse gases such as methane that would otherwise be released to the atmosphere. Establishing an anaerobic digestion process using the dairy feedstock, breaks down and captures the gases in the headspace of the digesters and through the gas upgrading system where it is cleaned of impurities and concentrated. It can then be transmitted to be used as a natural gas fuel alternative.

Our team implemented a series of strategic solutions to address the multifaceted challenges, extending the relationship with the client from the initial due diligence to extensive on-site support. The role ended up evolving to owner's advisor, responsible for guiding the team through the contractor selection and development of the RNG facility. Once the project was conceived, we assisted with bidding services, developed specifications, assisted with a host of operations and maintenance (O&M) improvements and efficiency, as well as health and safety and regulatory compliance requirements. Our team oversaw the design and portions of the construction.

The project included different sites to oversee:

• The main upgrader site, where the digesters from the former electricity production facility were replaced with the RNG plant

• The nine-mile pipeline stretch

• Construction management of the installation of canal casings

• Nine different canals that the pipeline had to cross

• Six remote dairy receiving sites for feedstock collection

• One feedstock pipeline for receipt from a nearby dairy site
  
  

The project called for comprehensive stakeholder coordination of multiple owner’s representatives, between contractors and subcontractors, along with navigating overlapping regulatory approvals and easement challenges across six different project sites.

As the project continued, we assisted with commissioning activities and will continue to collaborate closely with Meridiam to implement the Process Safety Management Plan.

The conversion of the diary biogas to electricity-to-RNG facility aimed to reduce greenhouse gas emissions and produce more efficient renewable energy. The digesters at the facility reduced the amount of manure returned to the environment by about 770 lbs per day. As for the community surrounding the facility, they will enjoy cleaner air, free from the hazards of toxic gases, such as hydrogen sulfide and methane with the reduction of over 240,000 gallons of diary waste throughout the waste process.

The project contributes to a circular economy by utilizing feedstock as a byproduct of the dairy industry and turning it into clean, green energy that can help decarbonize household and transportation fuel use. In fact, the anticipated RNG production will be distributed as renewable fuel for household and vehicle uses.