Cutting Greenhouse Gases: Biofuels That Don't Involve Food Crops Or Microbial Fermentation

California researchers plan to make biofuels in a novel way that doesn't involve food crops or microbial fermentation. A new research effort involving three University of California campuses and West Biofuels LLC, will develop a prototype research reactor that will use steam, sand and catalysts to efficiently convert forest, urban, and agricultural "cellulosic" wastes that would otherwise go to landfills into alcohol that can be used as a gasoline additive.

"We have a very feasible design to combine individual components of technology that have been proven separately into a successful biomass processing prototype," said Robert Cattolica, leader of the research program and a professor of mechanical and aerospace engineering at UC San Diego's Jacobs School of Engineering. Cattolica is the principal investigator of the project, which includes researchers at UC San Diego, Davis, and Berkeley.

Since carbon dioxide is naturally recycled from the atmosphere into cellulose in plants and back into the atmosphere as carbon dioxide when plants decompose, burning biomass-derived fuel such as alcohol in internal combustion engines has a zero net effect on the amount of carbon dioxide in the atmosphere. On the other hand, burning fossil fuels continually adds carbon dioxide, a greenhouse gas, to the atmosphere.

The new biofuels research project was inspired by California's Global Warming Solutions Act, which was signed into law by Governor Arnold Schwarzenegger in September 2006. The act requires a 25 percent reduction in greenhouse gas emissions in California by 2025. Substituting biomass fuel for petroleum would help California achieve its goal. The two-year UC project is funded with a $1.85 million grant from West Biofuels LLC, a San Rafael, CA, company that is developing the biomass-to-alcohol technology, and a $1.15 million state-funded UC Discovery Grant.

"My company is excited about partnering with the University of California on a very promising technology that could eventually have a significant beneficial impact on our environment while also reducing California's reliance on oil imports," said Peter Paul, chief executive officer of West Biofuels.

The alcohol currently added to gasoline sold in California is derived from corn, sugar cane, beets, or other farm crops. About 95 percent of the alcohol additive comes from outside of California and as far away as China. Rather than fermenting food crops into ethanol, Cattolica's project will use a thermo chemical process to break down shredded cellulosic wastes into a mixed alcohol, predominately ethanol. "The technology we're developing will tap a huge, energy-rich resource that now is literally going to waste," said Cattolica.

The prototype reactor will mix the wastes with high temperature sand in a reaction chamber while the mixture is heated with steam. The gasification process generates an energy rich combination of hydrogen (H2), carbon monoxide (CO), methane (CH4), and carbon dioxide (CO2). Those gases will be catalytically "reformed" into alcohols. About 30 percent of the energy content of the starting material will be burned to supply the energy needed to operate the plant.

This will actually include a three-step process. First, the biomass will be gasified thermochemically in a process that is widely used around the world to process wood, coal, and other carbon-containing materials into a "producer gas." The methane in producer gas is typically burned to power electricity-generating power plants. However, the new reactor will catalytically "reform" the producer it into syngas, a mixture of hydrogen gas and carbon monoxide. In the final step, the syngas will be catalytically converted into mixed alcohols with a "synthesis" catalyst similar to one developed in the late 1980s by Dow Chemical Company.

In order for all the processes to run at maximum efficiently, the researchers will make use of highly sensitive laser sensors developed at UCSD to continuously monitor the entire operation. Process-control algorithms under development at UCSD's Center for Control Systems and Dynamics (CCSD) will use the sensor data to continuously fine-tune steam temperatures and flows, gas mixtures, and catalyst regeneration to achieve the most efficient and reliable conversion of the biomass into fuel.

Cattolica's team, which includes nine UC professors and seven post-doctoral fellows, will conduct research on a $1 million, 4-ton-per-day reactor. West Biofuels is building the reactor and will donate it to the University of California. Lessons learned will be incorporated into a 100-ton-per-day pilot plant, which could generate one 10,000-gallon tanker truck of mixed-alcohol fuel for every seven semi-tractor trailer trucks of biomass waste. California generates a huge volume of such wastes.

The Orange County basin alone produces about 30,000 tons of urban green wastes per day, which is simply dumped at landfills and used as compost. Cattolica said that waste supply could generate 3 million gallons per day of mixed-alcohol fuel, which is equivalent to all the ethanol currently added to California gasoline.

The biomass processing technology could also permit California to reduce its dependence on outside sources of ethanol. Motorists in California currently purchase more than 900 million gallons of ethanol a year, or 25 percent of the national total. However, the state produces only about 5 percent of the ethanol fuel it consumes. Schwarzengger issued an executive order in 2006 that requires the state to produce at least 20 percent of its biofuels by 2010, 40 percent by 2020, and 75 percent by 2050.

Cattolica said green wastes generated in San Diego and the Los Angeles and San Francisco Bay areas represent a huge untapped energy resource.

"The more paper and cardboard, agricultural and forest wastes, and sludge and municipal solid waste that we can process into biofuels the sooner the state can meet the state's biofuels goals," said Cattolica. "This is all attainable, and it will allow us to continue using internal combustion engines, reduce our dependence on fossil fuels, and reduce the production of greenhouse gases."

I could give a rats behind about greenhouse gases until someone can make a persuasive case for anthropogenic climate change/global warming. So far no one has. I want energy self sufficiency for the U.S. This technique has the extra benefit of being a method for garbage disposal.

Well if they are fossil fuels from prior organic life does’nt the logic apply to that also? Most plants are co2 starved and are looking for that co2.

Maybe they could turn all the lipids collected from liposuction into oil too? :)

Actually, some dork has already done it. He took the fat from liposuction on his butt and converted it to biodiesel. Then he used it as a tiny bit of the fuel to sail around the world. Wish I had the link.

It’s bogus. We’ve been trying to find a viable gasification technology for 2 years. It’s simply not there. They may be able to make the fuel, but not profitably. Besides, you aren’t serious about gasification unless you can do 500 tons per day.

"I want energy self sufficiency for the U.S. This technique has the extra benefit of being a method for garbage disposal."

This basically boils down to gasifying garbage and using the syngas to make fuel. The only difference here is that the end product is intended to be "mixed alcohols" rather than hydrocarbons.

I've long wondered why such an approach wasn't tried---any major city probably processes enough carbonaceous waste into its landfills in a single day to replace all the fuel it uses for that same day.

you aren’t serious about gasification unless you can do 500 tons per day.

I did notice a lack of cost estimates in this article (or more to the point time). Along with the fact they are talking about a 4-ton reactor as the next step, these researchers are looking for money for their research. I suspect that it will take at lest two years with a 4-ton reactor before going to the 100-ton reactor. Then at least two years before main production, a reactor in the 500-1000 ton range.

The next question is how much yard waste can they conveniently acquire? A typical large chip truck for residential work can carry about 5 tons.

You’d be shocked at how much is out there between wood chips, landfill waste, dead animals, food waste, pet coke, tires etc. 500 tons a day sounds like alot but we found out it isn’t really that much. The problem is finding a gasifier that will run without problems and generate enough syngas to do something with profitably.

You’d be shocked at how much is out there between wood chips, landfill waste, dead animals, food waste, pet coke, tires etc.

I believe that much of that is already spoken for. The point is that to change the direction of these waste streams, you have to prove to those hauling it to the dump that this is a better use ($$$). I remember a presentation at the Allegheny SAF where the presenter showed one of the problems with firing power plants with wood chips, many of the studies showing there were sufficient supplies did not consider the already existing plants. Overlapping catchment areas.

As for getting the gasifier to work reliably at these rates in excess of 500+ tons a day, that will take 5-10 years from the start of scale-up.

"As for getting the gasifier to work reliably at these rates in excess of 500+ tons a day, that will take 5-10 years from the start of scale-up"

Everything I have read on Energy and Alternatives to Oil is that the return on investment of alternative froms never comes close to Oil. And I mean on the actual energy invested to get more energy.

From what I read, oil is 4:1 return on investment. Invest one unit of energy and you get four back. The Best any of the present froms of alternative fuels is offering so far is a 2:1 R.O.I.

However if a system can be put into place that rescues wasted energy (stuff that is sent to landfills and such) then I would surmise the system would work. That is "IF" it can be done so to be competitive financially. However I fear it will be setup as a feel/good Congressional endless moneyhole.

However I fear it will be setup as a feel/good Congressional endless moneyhole.

I think this is likely. Similar things happened with SUNY's process for hybrid willows as fuel for power plants: The process was for ~twenty years a research project for several Ag (forestry?) professors, untill a jump in fuel prices suddenly made growing willows on marginal cropland seem like a profitable proposition, and private entities took up what the good professors had been working on for years. In New England they burn so much wood for Electricity that the price of pulpwood tracks the price of coal.(~equal in terms of $per BTU)

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