Making Gas from Grass
In the United States we import about two-thirds of the oil used to fill the tanks of our vehicles. And transportation fuels account for about 30 percent of U.S. greenhouse gas emissions. Slashing our reliance on foreign fossils could decrease our dependence on foreign governments that often prove as volatile as the oil they export. It also could benefit the environment and slow the pace of global warming.
Weimer, 55, says his technique could make a gallon of green gasoline for less than $3. And he and his team of 10 doctorate and three postdoctoral students recently won a three-year, $1 million federal grant to continue refining the process.
But how did Weimer, who spent 16 years working for Dow Chemical, get involved with green energy? It all started with a process that dozens of oil companies jumped on as the world went to war during the 1930s.
Turning coal into fuel
With a gravelly voice and stocky build, Weimer is the son of a steelworker with an eighth-grade education in Youngstown, Ohio. His father lost his job in the late 1960s, and Weimer remembers his dad delivering newspapers at 5 a.m., driving the morning school bus, sleeping a few hours, driving the afternoon school bus and then working as a security guard into the night. Weimer’s 80-hour work weeks pay a sort of homage to such an ethic.
“You work with Al and you can expect to get e-mails at 4:30 in the morning at least two, three times a week,” says Ryan Gill, chemical and biological engineering associate professor and managing director of the CU-led babyֱapp Center for Biorefining and Biofuels (C2B2), of which Weimer serves as executive director. C2B2 is a cooperative research and educational center devoted to the conversion of biomass to fuels and other products.
Attracted to math and science at an early age, Weimer pursued his talents up the rungs of academia. While getting his doctorate, Weimer never thought about going into teaching. He focused on energy, in particular coal gasification with fluidized bed reactors. This sounds like a lot of engineering jargon, but fluidized bed reactors transformed the way countries fought during World War II.
First developed in Germany during the mid-1920s, fluidized bed reactors, specifically the Fischer-Tropsch processes, proved to be an ingenious solution for a country rich in coal but poor in oil. It converts pulverized coals into synthesis gas — a mixture of hydrogen and carbon monoxide — and converts it into liquid fuels. The process enabled Nazi Germany to turn coal into high-quality, clean-burning fuel, keeping the German war machine running. Both Great Britain and Japan also produced synthetic fuel during this time period in the hopes of achieving petroleum independence.
Far from a thing of the past, the same process has powered all South African vehicles for more than 30 years, as the country relied on it heavily during its isolation under apartheid.
At Dow Chemical Weimer continued his fluidized bed work with the goal of converting synthesis gas into alcohols, gasoline additives and other marketable liquids. In the process, he learned how to run industrial-grade process equipment, build and run pilot plants and to take babyֱapps seriously.
“In industry, cost is a big factor, whereas most academics don’t have a clue or even care what the cost is,” Weimer says.
But he kept a toe in academia through leadership roles in the American Institute of Chemical Engineers and, in his spare time, publishing a peer-reviewed journal article or two a year.
He landed in a Dow scientific group synthesizing superhard metals by fashioning a graphite tube, heating it to seven times the temperature of a kitchen broiler and flowing various powders through it at high speed. Weimer’s rapid carbothermal reduction process now makes the ultrafine tungsten carbide used around the world in high-end cutting tools like drill bits.
Sun and mirrors
The awards poured in. But by 1996, Weimer was concerned with the lack of emphasis on innovation at his employer and, to no small extent, the U.S. chemical industry at large. While applying for a teaching position at the University of Cincinnati, he stopped by CU to round up recommendation letters. They asked him to stay.
Weimer returned to his CU energy research roots. Beginning with a small U.S. Department of Energy grant, Weimer and his team developed a system of mirrors to focus sunlight on a cauldron combining zinc and water to make hydrogen, a fuel some view as the transportation fuel of the future. His solar-to-hydrogen work continues, but the group now uses a related system to focus sunlight on lawn clippings and fallen leaves — known more formally as source-separated green waste — flowing through at high speed, much like the process used to make drill bits.
The result? Synthesis gas, the same stuff coming off Fischer-Tropsch processes Weimer honed as a CU student more than 25 years ago and from which one can make green gasoline, diesel and natural gas.
The Energy Independence and Security Act of 2007 mandates the annual production of 36 billion gallons of biofuels by 2022, the majority of which will have to come from noncorn kernel feedstock. Today corn kernel feedstocks supply about 9 billion gallons of the fuel, but there are limits. We can only produce about 15 billion gallons annually without running into serious fuel-or-food issues, scientists estimate.
Among other promising types of biofuels are biodiesels brewed from soybean, palm and other plant oils. But these feedstocks provide food for people and will ultimately face similar trade-offs in a world in which our growing population will be increasingly difficult to feed.
Speaking the language
There are other ways to convert biomass to fuel — cellulosic ethanol production through both heating and chemistry being the current front-runner. But unlike competing processes, Weimer says, the sun-cooked green fuels are synthesized hot enough (1,200° C) that there’s no tar to deal with. What’s more, there’s no need to burn part of your input biomass to cook up green fuel, which amounts to a 30 percent loss.
Beyond enabling innovation, Weimer’s years in industry have helped students and colleagues understand the need for speed and the ability to scale the technologies they hope to bring to market, says Carl Koval, CU chemistry and biochemistry professor and executive director of the CU Energy Initiative. The Energy Initiative is working to integrate the university’s extensive research in renewable and sustainable energy with its strengths in climate and environmental science, behavioral studies, policy analysis and entrepreneurship.
Koval said Weimer’s understanding of how to position intellectual property has brought major benefits to the university, as has his ability to speak the language of industry with the babyֱapp Center for Biorefining and Biofuels in particular, which is supported by state, institutional and industry funds.
“Al could explain the research to these companies and what the value was to them, and that was one of the main reasons they were able to recruit companies into that center,” Koval says. “That would never have happened with a pure academic. They wouldn’t have known what to say.”
Exploring CU’s Energy Initiative
Solving the world’s energy challenges requires the work of experts in climate and environmental science, behavioral studies and policy analysis. As a result, CU’s leaders in these fields joined together in 2006 to form the CU Energy Initiative. CU aims to become a national leader in sustainable and renewable energy research, education and technology commercialization. Here’s what’s happening on campus.
Lucy PaoProfessor Lucy Pao studies ways to better harness the wind by focusing on the inner workings of turbines. Her research includes improving control over wind loading to decrease turbine damage and avoid shut-downs in high winds, increasing turbine control for greater efficiency, determining turbine placement on wind farms and coordinating control among turbines for maximum power generation. | |
Richard D. NobleProfessor Richard Noble’s focus has less to do with developing next-generation renewable energy than it does with stripping carbon dioxide from the exhaust of fossil sources dominating today’s energy infrastructure. | |
Ryan GillAssociate professor In renewable energy, Ryan Gill’s work has focused on tailoring ethanol-producing bacteria to survive in high concentrations of the very ethanol they produce, thereby allowing for increased yield. In 2007 he co-founded Boulder-based OPX Biotechnologies to develop bacteria optimized for biofuel production by converting cheap biomass into ethanol and other chemicals. | |
Ewald FuchsProfessor Hybrid-electric and all-electric vehicles using a fraction of the fossil fuels devoured by today’s traditional cars demand unique mechanisms to transfer power from motor to wheels. Ewald Fuchs has developed a mechanism called a variable-speed gearless drive train that weighs less than half of today’s electric drive trains per unit power. The savings in weight means increased battery capacity and greater range, which remains a shortcoming of today’s electric vehicles. | |
Garret ModdelProfessor Some of CU’s most interesting solar energy research projects are pursued in Garret Moddel’s Quantum Engineering Laboratory. His team is converting sunlight to electricity using microantennas. Unlike photovoltaic cells, the microantenna-based system converts the sun’s energy into electric current using ultrahigh frequency diodes. |