A simple (one step) direct conversion process from plant cellulose into gasoline components; a new kind of grow op

Researchers have made a breakthrough in the development of "green gasoline," a liquid identical to standard gasoline yet created from sustainable biomass sources like switchgrass and poplar trees.

Reporting in the cover article of the April 7, 2008 issue of Chemistry & Sustainability, Energy & Materials (ChemSusChem), chemical engineer George Huber from the University of Massachusetts-Amherst (UMass) and his graduate students Torren Carlson and Tushar Vispute announced the first direct conversion of plant cellulose into gasoline components.

In the same issue, James Dumesic and colleagues from the University of Wisconsin-Madison announced an integrated process for creating chemical components of jet fuel using a green gasoline approach.

While Dumesic's group had previously demonstrated the production of jet-fuel components using separate steps, their current work shows that the steps can be integrated and run sequentially, without complex separation and purification processes between reactors.

"It is likely that the future consumer will not even know that they are putting biofuels into their car," said Huber. "Biofuels in the future will most likely be similar in chemical composition to gasoline and diesel fuel used today. The challenge for chemical engineers is to efficiently produce liquid fuels from biomass while fitting into the existing infrastructure today."

For their new approach, the UMass researchers rapidly heated cellulose in the presence of solid zeolite catalysts, materials that speed up reactions without sacrificing themselves in the process. They then rapidly cooled the products to create a liquid that contains many of the compounds found in gasoline.

The entire process was completed in under two minutes using relatively moderate amounts of heat. The compounds that formed in that single step, like naphthalene and toluene, make up one fourth of the suite of chemicals found in gasoline. The liquid can be further treated to form the remaining fuel components or can be used "as is" for a high octane gasoline blend.

From the paper, entitled: "Green Gasoline by Catalytic Fast Pyrolysis of Solid Biomass-Derived Compounds"

"Herein, we report that gasoline-range aromatics can be produced from solid biomass feedstocks in a single reactor at short residence times (less than 2 min) and intermediate temperatures (400-600 8C) by a method we call catalytic fast pyrolysis.  Fast pyrolysis involves rapidly heating biomass (500 8Cs_1) to intermediate temperatures (400-600 8C) followed by rapid cooling (vapor residence times 1-2 s).Fast pyrolysis produces a thermally unstable liquid product called bio-oil, which is an acidic combustible liquid containing more than 300 compounds.Bio-oils are not compatible with existing liquid transportation fuels including gasoline and diesel.  To use bio-oil as a conventional liquid transportation fuel, it must be catalytically upgraded. As we show here, introduction of zeolite catalysts into the pyrolysis process can convert oxygenated compounds generated by pyrolysis of the biomass into gasolinerange aromatics."

"In theory it requires much less energy to make than ethanol, giving it a smaller carbon footprint and making it cheaper to produce," scientists said. "Making it from cellulose sources such as switchgrass or poplar trees grown as energy crops, or forest or agricultural residues such as wood chips or corn stover, solves the lifecycle greenhouse gas problem that has recently surfaced with corn ethanol and soy biodiesel."

"Not only is the method a compact way to treat a great deal of biomass in a short time, researchers emphasized that the process, in principle, does not require any external energy. "In fact, from the extra heat that will be released, you can generate electricity in addition to the biofuel," he said. "There will not be just a small carbon footprint for the process; by recovering heat and generating electricity, there won't be any footprint."

ETA: 2013-2018

While it may be five to 10 years before green gasoline arrives at the pump or finds its way into a fighter jet, these breakthroughs have bypassed significant proof-of-concept hurdles to bringing green gasoline biofuels to market.

Look for a new legal or illegal  home-grown cottage industry, a high tech still in every backyard? a new kind of grow op !!

Comments

[Andrew Opala]

The essence of replacing gasoline with synthetic fuels is meant to minimize the shock to the entire delivery and usage chain. Keeping the auto industry, the gasoline companies and everything that lives off this from lots of distruption.

However, creating long carbon-chain molecules that are "like" gas may be a waste of energy. We are just making carbon bonds when we make the fuel (like storing them in a battery) and then break them in the combustion process (discharging the battery) when the fuel is burned. Using a smaller and easier to produce molecule (Methane for example) would be a better choice than Gasoline for this "battery" analogy.

I think after reviewing cost of production, time-to-market, and availability of raw materials, there will be a push for cars to be "tri-brid" - methane/gas/electric.

Methane and electric are the most sustainable and the easiest to get from a plug in the wall (from the natural gas company or from the electric company).

This is the distruptive model that will create a sustainable economy rather than to maintain one with a limited future (in recreating Gasoline).