Coal Plus Biomass - The Next Generation of Fuels

 
 
First, in case you weren't aware of innovation, an intro:
 
"innovation: America's Journal of Technology Commercialization, formerly TechComm, is a bimonthly magazine published ... in partnership with the US Department of Energy. It reports on new technologies, entrepreneurial activity, topics of interest to investors, activity at DOE and other national laboratories, and issues concerning technology transfer."
 
Some excerpts, edited, as indicated, for concision:
 
Next-Gen Fuels--What’s Old Is New Again
 
June/July 2008
 
By Howard Brown
 
"Al Darzins ... at the National Renewable Energy Laboratory ... finds himself spending a lot of time these days looking at ... some of the laboratory’s earli­est research. As group manager ... he is overseeing several “new” research efforts that build on some very old ones. His efforts are aimed at converting biomass—algae and plant-derived materials—into fuels."

"“Previous biofuels work performed at NREL under various programs has provided a strong foundation for our current efforts to kick-start that research again,” says Darzins."

"Today ... three of these technologies—the production of pyrolysis oil, liquefied synthesis gas (both of which can be obtained from coal) and microalgal oil—are once again attracting a lot of attention."
 
"Coal was once the transportation fuel of choice for the United States ... But ... gasoline and diesel fuel became the domi­nant transportation fuels."

"... it can be well worth expending energy to convert solid fuels—whether they be biomass or coal—to liquids. By heating biomass to very high temperatures with limited or no oxygen, researchers can either liquefy or gasify it. When biomass is lique­fied, the resulting pyrolysis oil can be used after pretreatment as a feedstock for conventional oil refining. When it is gasified, the synthesis gas can be catalytically converted to liquid fuels that substitute well for diesel or gasoline."

"In fact, the pyrolysis and gasification technologies used for converting biomass to liquids were initially ap­plied to coal to produce petroleum substitutes. With a strong utility interest in integrated gasification and combined-cycle technologies for coal power (so-called “clean coal” technologies), gasifier technology has advanced significantly."

(Note of the foregoing. It emphasizes the point that CoalTL technologies can be applied to some biomass. CoalTL and BioTL are not just complementary, but, because of the biological carbon cycle, synergistic.)
 
"While the core technology has advanced, biomass pyrolysis and gasification are gaining renewed interest in part because of the emphasis on producing ethanol from cellulosic biomass, such as wood chips and plant leaves and stalks."
 
"Cellulosic biomass is made up of cellulose, hemicellulose and lignin. Cellulose and hemicellulose are plant-derived, sugar-based polymers, and biological biomass conversion technology can ferment the sugars to ethanol. But lignin, the third major component of biomass—making up 15 to 25 percent of biomass by weight—does not contain sugars."

"Until recently, NREL’s process designs for ethanol production called for burning the lignin to provide heat and power for the ethanol plant. But with transpor­tation fuels as a top priority, the new thought is to use multiple technologies to produce fuels. Because thermochem­ical processing can produce fuels from any biomass source (and coal!), not just sugars, researchers can use it to convert the lig­nin and any other residue from biologi­cal processing to additional ethanol or other liquid fuels within the same bio­refinery." (As we have been suggesting.)

"Also, biological processing is currently focused on agricultural residues such as cornstalks and husks. Other biomass—particularly softwoods (i.e., cellulose ), which may be­come extensively available from forest thinning operations—is more challeng­ing for fermentation and may be more suitable for pyrolysis or gasification (as applied to coal)."


"Full Circle on Pyrolysis Research"

"NREL’s research on biomass pyrolysis has returned to its roots. (It's roots lie in coal gasification for "town gas" production, as we've documented - in the 1800's. The gas wasn't liquefied, as in the following.) Pyrolysis involves liquefying biomass by first heating it to about 550C in the absence of oxygen and then condensing the vapors. The resulting pyrolysis oil is a complex mix­ture analogous to crude oil (except that it contains oxygen) and can be burned as fuel or, after pretreatment, used as a feedstock for con­ventional oil refineries."

"NREL’s original pyrolysis research had that direct product as its objective, but in the late 1980s, the laboratory turned its focus to making specific fuel ad­ditives or other petrochemicals from pyrolysis vapors before they condensed."
 
"NREL researchers worked on crack­ing the vapors to aromatic hydrocarbons and olefins that could be used as gasoline blends." (They worked on it. Why did they stop?)

"“The goal is to make pyrolysis oil (obtainable from coal, biomass and sewage sludge) a stan­dard petroleum refinery feedstock,” says Czernik (NREL researcher Stefan Czernik). One project is exploring the suitabil­ity of pyrolysis oil derived from lignin (from trees) for such a feedstock. NREL produces the pyrolysis oil, and research part­ners at the Pacific Northwest National Laboratory and UOP LLC, a private petroleum research company, hydrotreat it; that is, they upgrade it by removing impurities. Among other things, the process removes oxygen, which is the primary difference between pyrolysis oil and crude petroleum."
 
UOP - Honeywell

"NREL is conducting techno-economic and life-cycle analyses of the biorefinery pathway involving lignin pyrolysis and hydrotreating to determine how profit­able it will be, what kinds of energy and environmental impacts it would have, and what changes could be made to most effectively improve that profitabil­ity and impact."

"A second project seeks to upgrade pyrolysis oil during its  production by reacting either the condensed oil or the oil vapors with ethanol (which can also be obtained from coal - JtM) . Researchers expect this process to reduce the acidity of the pyrolysis oil and make it more stable, both of which would improve its suit­ability as an oil refinery feedstock."

"Because of the potential for either hydrotreating or ethanol upgrading, or a combination of both, the future for pyrolysis oil appears bright."

"“We think pyrolysis is a powerful tech­nology and are eager to use it to help meet transportation fuel needs,” says Czernik."

From Solid to Gas to Liquid

"Another approach to converting solid biomass into a liquid fuel is to first con­vert it into a gas. NREL scientists gasify biomass to a mixture of carbon monox­ide and hydrogen, known as synthesis gas or syngas (Just as can be done with coal), by taking the pyrolysis process a step further—heating it to about 850C with about one-third the oxygen needed for efficient combustion."

"In the 1990s, syngas (from coal) was envisioned pri­marily as a fuel for electrical power gen­eration, with a focus first on large utility systems and then on smaller distributed generation systems. The shift from elec­tricity production back to liquid fuels is in large measure a tribute to the great gains made by wind turbines, solar cells and other renewable energy technolo­gies for power generation. When it comes to liquid transportation fuels, however, biomass is the only renewable game in town."

"Conversion of syngas to liquids also has a colorful and somewhat dark history. Franz Fischer and Hans Tropsch first studied conversion of syngas into larger, useful organic compounds in 1923. Using syngas made from coal and metal catalysts, they were able to produce liq­uid hydrocarbons. Fischer-Tropsch sys­tems were used successfully in Germany during World War II and South Africa during apartheid embargoes when each faced limited oil supplies. Several commercial Fischer-Tropsch operations continue today, and the term Fischer-Tropsch has come to be applied to any catalytic conversion of syngas to liquid fuel."

"The NREL syngas-to-liquid system bub­bles the gas through an oil slurry under high pressure, with the catalyst sus­pended in the liquid. While traditional Fischer-Tropsch processes seek to pro­duce non-oxygenated hydrocarbons, NREL’s objective is to produce ethanol or perhaps “higher alcohols”—a mixture of ethanol and larger-molecule alcohols."

"“The process is similar to Fischer-Tropsch or methanol reformation,” says NREL scientist Steve Deutch, “but we stop it at an earlier stage.”"

"Producing ethanol from syngas would be an ideal companion technology for a biorefinery that ferments biomass into ethanol because the syngas process would produce ethanol from mate­rial that cannot be fermented, such as lignin (and coal! - JtM). Because both processes would produce ethanol, the approach would avoid the need for additional infrastruc­ture to deliver another product, such as a lignin-derived chemical."

"NREL is currently working with PNNL on a joint effort to produce al­cohols from syngas. PNNL is working to improve the catalyst, while NREL is focusing on improving the process con­ditions and testing the catalyst and pro­cess against a wide range of operating conditions, using actual syngas derived from biomass."

An Aquatic Approach to Future Fuels

"Yet another early biofuel research area that is back in the spotlight is the con­version of algae to fuels. Although small in size compared to cellulosic ethanol efforts, the NREL research effort on fuels from algae involved extensive research through the 1980s and early 1990s. NREL’s biomass researchers led the way in developing technology for growing microalgae that produce high levels of lipids (oils) for processing into biodiesel. NREL developed an extensive microal­gae culture collection as well as a tool kit for the genetic engineering of these organisms. Former NREL analyst John Sheehan, who managed the last few years of the microalgae program, cited economic factors for its being set aside."

"“In addition to having to compete with 57-cent-per-gallon diesel at the time (That's certainly changed), one of the main reasons for dropping the microalgae program was realizing that even using simple outdoor ponds, the capital cost of facilities for growing the microalgae would always keep the technology relatively expensive,” says Sheehan." ­

“Today, however—in addition to dramatically higher petroleum diesel cost—low plastic container cost makes the possibility of growing the algae in closed systems such as transparent tubular reactors (reactors, we suggest, connected to the exhaust flues of coal-fired power plants and coal-to-liquid conversion factories) a very realistic possibility­ and is making the technology much more attractive again.”"

"NREL scientist Eric Jarvis, a genetic en­gineering specialist, is especially excited about the possibility of restarting micro­algae research because of new capabili­ties developed since the mid-1990s."

"“The metabolic engineering we did to try to make microalgae produce more lipids was cutting edge at the time,” says Jarvis, “but the whole field of genetic engineering has advanced so dramati­cally since then that we will now have far greater ability to improve the organ­isms’ performance.”"

"Another exciting reason for reestablish­ing microalgae research is the possibility of developing a new end product. Rather than converting the microalgal oil to biodiesel, it is possible to chemi­cally convert it to jet fuel. The same hydrotreating process that could make pyrolysis oil a good oil refinery feed­stock could also convert microalgal oil into kerosene, the basic component of jet fuel."
 
(And, again, we can grow the algae in bio-reactors connected to the exhaust flues of our coal plants. We'll note that several airlines, such as Virgin, have tested algae-based jet fuel, as we've documented.)

"Jet fuel now accounts for about 8 percent of our petroleum use and no renewable alternative has been developed to this point. Ethanol is not dense enough, hav­ing only about half the energy per vol­ume of jet fuel. Biodiesel has about 80 percent the energy density of kerosene, but can solidify at the low temperatures of high altitude flight."

Howard Brown is a senior communicator at NREL., and it might well be worth your time to have a few words with him, presuming your interest. We know the foregoing has been an overly-long presentation, but the fact that it is so long serves, we think, to highlight the fact that there are a lot of things going on, developments underway, that could be positive for all of us - West Virginia, the Coal Industry, the US.