A growing company in California is attempting to turn waste into energy, and the University of Wyoming could help.
Sierra Energy is creating a gasifier — a device used to extract synthesis gas from landfill rubbish and tires to low-grade inefficient coal. Synthesis gas is a mixture of mostly hydrogen and carbon monoxide and can be refined in to other substances.
“For us, the intent was to take municipal waste, move them through a system and create a synthesis gas that can be primarily used for three main things — electricity, hydrogen and then, possibly most excitingly, Fischer-Tropsch diesel,” Sierra Energy Chief Strategist Rob White said. “We are inviting in the academic community because we know there are many innovations that could happen that we’re not working on.”
White and other Sierra Energy companies are working with the state government and UW for a possible researching partnership, petroleum engineering professor Maohong Fan said.
“Collaboration is dependent on opportunities and funding, and there is no set schedule, but we benefit each other,” he said.
Synthesis gas emitted from the gasifier is not immediately profitable, Fan said UW research would work on that part of the project.
“We could focus on the downstream part,” he said. “We’d look at the syngas part and see if we can get different products. Right now, you get carbon monoxide and you get hydrogen — but we look at how to use it and make more valuable chemicals.”
Sierra Energy already has a testing version of its device, which Fan compared to a blast furnace.
“The waste starts on a conveyer belt and is dumped into the top, which is 400 degrees at the top and 4,000 at the bottom,” White said.
Gasification is not incineration, White explained — there is no combustion in the chamber. The high heat breaks down materials on a molecular level, creating the synthesis gas and slag, which can be repurposed for road base or reprocessed to extract some of the metals. White said it looks like a piece of obsidian or the glass beads normally used in aquariums.
“You’re putting in waste and heat, and you’re getting gas and glass,” he said.
White explained a possible scenario for a gasifier’s use at a Wyoming coal mine. Mines produce an amount of lower-grade coal not fit for shipping, which is normally put back into the mine. The mine’s equipment also wears down tires, leaving an abundance of used tires.
“Those tires can easily be shredded, and the system we have loves that carbon-rich feedstock,” White said. “The metals in the tires don’t bother the system and, on top of that, they can throw in some of that low-grade coal and power their operations at the facility through electricity or Fischer-Tropsch diesel to power their equipment.”
The scenario is forward-thinking, White said, and not something immediately planned.
The company had not considered using the waste coals until recently — originally, the U.S. Department of Defense granted funds to create a zero-waste base and a gasifier that could be used in forward operating bases in the field.
There are still several problems to overcome, White explained, which is why continued partnerships with universities is important. Analysis for greenhouse gas emissions from products like PVC is ongoing. Some metals, like mercury found in batteries, are also in landfills and would likely go into the gasifier with other materials, and the company still searching for a way to handle such metals.
There is money available to help fund research in the gasification field, White said, which could be used by various institutions.
“This year alone, in the low-carbon fuel area, there is over $250 million being distributed to companies to demonstrate and show what they can do,” he said. “From a university standpoint, that’s a good pot of money that can be captured to do some of the work that’s already being done on this campus.”