For decades California has led the world with clean air regulations. Now, CR&R Environmental will be fuelling some 80 vehicles with upgraded biogas from organic wastes.
In Perris, California, CR&R Environmental is nearing completion of a 1.4 mile (2km) pipeline connecting its anaerobic digestion plant to the gas grid. The privately held firm serves more than 50 communities in the Southland area of California, which extends from the Mexican border to LA, where it serves around 3 million people and 58,000 businesses.
“We designed the facility in four phases,” explains Paul Relis, senior vice president, at CR&R Incorporated. “Each phase has a capacity of 83,000 tons per year. We’ve completed phase one and are operating it. We will complete phase two about the same time that the pipeline interconnect completed this June and we’ve applied for grant funding to assist with Phase III so we’re on a steady growth curve.
Speaking with WMW Relis says that unlike some AD operators, CR&R tied the project to its core business. “What we do is offer the anaerobic digester to communities who are interested in having a long term solution to organics, and who want a fleet of vehicles operating in their community with ultra low emissions.”
Around 15 years ago the South Coast Air District introduced a rule whereby if a company had a fleet of five or more vehicles it would have to convert them to operate on Compressed Natural Gas (CNG) as their contracts were renewed.
“There has been a conversion in the solid waste industry away from diesel towards natural gas,” explains Relis. “Now there’s a drive to reduce short lived climate pollutants and one of the most effective ways is to use renewable natural gas – in our case produced by waste from the cities we serve.”
“Because we’re in Los Angeles Metropolitan South we have the worst air quality in the United States,” he continues. “The communities are under pressure to continually improve emissions and that's one of the big selling points of our system. We guarantee that we’ll operate the collection system in the community on renewable natural gas.”
He adds that the other main driver of change is the increasing prohibition of disposing of organics in landfill in California, which is putting cities under pressure to find alternatives. That only leaves two main options, composting and anaerobic digestion. For CR&R the choice was obvious and the company has so far convinced 11 of the cities it operates in that the preferred path is to extract the energy content of the organics first, before composting.
Years in the Making
For any project on this scale the process of getting from concept to fruition is a long one.
“We’ve been at this a long time,” says Relis. Our system is unique and reflects our operating philosophy of building on what we know and provide the highest quality long term service we can for our communities. Our technology is designed to be effective for managing residential organic waste, which is largely lawn clippings along with food waste that is deposited in the “green can” used in it’s automated collection system. In Southern California we have a continuous growing season, so we wanted a system that could process curbside “clean green primarily.”
The facility processes only source separated organic materials and does not take general waste. “ We wanted to avoid the contamination issues associated with processing mixed municipal waste.”
“We have a one-acre receiving area for organics and in that building we have a lot of equipment that make this a “green waste MRF”. We have both manual processes and very sophisticated, grinders and screens and other separators. You never completely remove the human factor from quality but we’ve invested around $5 million in the treatment of the organics even though they are already source separated.”
When it comes to ensuring the quality of the digestate Relis says that most of the regulations come from the California Water Board which controls the application of digestate on farms and for other uses.
“There’s water quality requirements which have to be met, but then there’s also time and temperature regulations to control pathogens and so on,” he explains. “We have a full laboratory and talented operating team to meet our compliance obligations.”
During the design phase of the project the company selected Eisenmann as it’s core technology partner. The German firm, which has a US operation based in Chicago, offers a High Solids Anaerobic Digestion system. It employs a continuously fed, horizontal plug flow design which allows for maximum biogas production, a high degree of consistency and full automation.
“They’ve been really top draw,” comments Relis. “It’s a new industry so you really want to work with a company that has the resources and know how to stay with a long development process and support it afterwards. We have the exclusive rights to their technolgy in the state of California and we’re hoping to build more facilities in the future.”
Grid Connection
In Southern California there are a number of large publicly owned utilities called investor utilities which operate the gas network. To get connected to the network CR&R chose to work with the largest, Southern California Gas Co. (SoCalGas), which owns the distribution network.
For regulatory reasons the utility is not allowed to be involved in the anaerobic digestion business itself. For CR&R that means that it will be able to supply upgraded biogas to the utility via a soon to be completed pipeline.
Using technology developed by Greenlane Biogas the facility uses the Totara System of Greenlane employing water scrubbing and other advanced technologies to clean raw biogas to required specifications for vehicle fuel or pipeline injection.
For its part, Greenlane was involved in detailing a design solution to enable the RNG produced at the facility to meet the stringent Rule 30 requirements for injection into California pipelines. Rule 30 is a guideline created by the state utilities specifying the pipeline gas quality RNG producers must meet in order for RNG to be received and distributed. One standard in Rule 30 that has inhibited producers from injecting their RNG into pipelines is the requirement for the RNG to have a heating value of 990 BTU/SCF.
According to Greenlane, to meet the 990 BTU/SCF criteria, a higher heating value fuel such as propane, would normally need to be blended into the RNG. This practice reduces the “green” content of the RNG and it may be cost prohibitive. Lower heating value requirements for RNG, most commonly 960 BTU/SCF, have been adopted in other states making the California requirement the most rigorous in the US.
With a capacity range of 400 to 1,250 standard cubic feet (11.3 to 35.4 cubic metres) per minute, the Totara system will initially convert biogas into the equivallent of 1 million gallons (3.79 million litres) of diesel equivalent.
“Our raw biogas is about 50% methane. We initially clean that up to fuel grade, which is about 97% methane, but to be at pipeline quality we need to be at around 99% methane, so we had to add some additional equipment which is quite expensive – around $1.5 million,” says Relis.
"Bringing renewable gas into our pipeline system is a big step forward for SoCalGas and for California," adds Lisa Alexander, SoCalGas' vice president, customer solutions and communications. "Using our pipeline infrastructure to distribute this carbon-neutral fuel will help to slow climate change and meet state goals for increasing use of renewable fuels. We see this de-carbonisation of our pipeline system as the way of the future."
Over the Horizon
When it comes to the future of the industry in California Relis is cautiously optimistic and says that the company is already exploring the possibility of developing other similar facilities. “Because we’re a policy driven and a service industry we need to keep a sharp eye on policy and regulatory trends that can impact the “green values” attributed to our technology. We must also play close attention to educating our customer base and the city council’s and other government agencies so they understand and value the sophisticated organics system that we’ve developed. Our consistently high-quality service to our communities over many years has a established an essential trust factor
on their part. Nowhere is this more evident that with the City of Perris that appreciates how our facility contributes to its green aspirations and the quality of life for its residents and businesses.
