A recent article published by The Press-Enterprise provided false information about UCR researchers currently studying the potential benefits of fecal matter in the renewable gas (RNG) sector. In an interview with the Highlander, Arun Raju, director of the Center for Renewable Natural Gas (CRNG) and assistant research engineer at UCR’s Bourns College of Engineering, clarified that he and the writer of the Press-Enterprise article, Mark Muckenfuss, “didn’t even discuss anything about human waste to RNG. While it is doable, the guy just came up with that.”
When asked about what exact research projects the CRNG has planned or is currently running, Raju said, “We have a lot of projects that we are working on but it is probably premature to say a specific project because we never know until the project is funded.” He and CRNG are still in their research and development process of identifying “specific projects in terms of the technology, the location, the size and whether it has to be pilot or larger scale or other things.”
One example of Raju’s ongoing projects is one “that is looking at the potential of RNG in California, as in how much RNG can be realistically produced. That is one goal, but the other goal is to identify specific technologies that are the most viable in commercially producing RNG as quickly as possible,” he said.
Raju also provided insight into the divisions of renewable energy, carbon based versus non-carbon based. “Non-carbon based energy can be claimed from solar energy systems, wind energy systems and nuclear energy systems. All of these are electrical generation technologies,” and since a big portion of energy used is electricity based, Raju said it is a very big sector of renewable energy research. On the other hand, “we use a lot of fuel and almost all the fuel we use is carbon-based energy,” since it is used for transportation, heating and cooling and electronic products.
Despite the success with switching to renewables, it has been mostly in the electricity sector with solar, wind and hydro power, but “if you look in the fuel sector, especially transportation, not much has happened,” explained Raju. One of the research areas that he and the Center for Environmental Research and Technology (CE-CERT) have been working with is renewable fuels, such as the development of synthetic diesel and methanol. To produce renewable fuels, carbon-based feedstock or biomass is required which, Raju said, “we at CE-CERT give a very broad spectrum to include wood, municipal solid waste, sewage sludge, yard waste and agricultural residues.” All of these carbon based materials can be converted into fuel.
“The way to convert it is through gasification, by taking the carbon feedstock and use some chemical reactions to break it down into a synthesis gas, hydrogen and carbon dioxide, which becomes the raw material to produce fuel,” said Raju. This process is something UCR uses heavily and owns a patented-technology called steam-hydro gasification process. There are other ways as well, such as fermentation to produce ethanol.
In regards to the Press-Enterprise article that was published, Raju made clear that “We (CE-CERT) have done a lot of this work with our patented technology in the past. We have taken sewage from the waste treatment plants and trash from landfills to turn it into fuel. We are not doing experiments right now but as a part of the center, we are planning to demonstrate these conversion technologies soon.”
He concluded that though there may be new technologies available to produce RNG, they still lack commercial viability because they are not compatible with large industrial use. However, the process of gasification can change the industry because it uses all types of carbon-based feedstocks, whereas the present methods to produce RNG only use a certain type of feedstock. “RNG has a lot of potential to make an impact. If you look at it’s carbon intensity, it has some of the lowest carbon intensities of transportation fuels. There is a need for RNG productions in very high volumes but the technology is still not there. We’re hoping to change that with CRNG,” assured Raju.