More uses for biofuel byproducts on the way

Researchers, entrepreneurs, and venture capitalists nation-wide are looking for potential uses for the byproducts from large scale biofuel production. Researchers hope to achieve an industry similar to the traditional oil refinery industry where as the raw material is processed, a multitude of products are produced in addition to the primary product (fuel). Researchers believe that as more value is obtained from these byproducts, the economic viability of biofuels such as ethanol will increase.

One company, Purevision, is working on a way to convert lignin so that it can be used in glues, sealants, and detergents. “Most plans for cellulosic ethanol processing call for burning the lignin to generate steam and heat to run the process. As a fuel, lignin is worth around $40 a ton. PureVision has devised a way to make a different form of lignin–one with a molecular composition that could make it an attractive material for a variety of industrial products like glues, sealants and detergents. Ed Lehrburger, PureVision’s founder and chief executive, said he thought his lignin could sell for $300 a ton or more. Lehrburger said his company was collaborating with a wood and paper products manufacturer that is interested in using the lignin for a biobased glue for its laminates, plywoods and other products.

Lignin makes up roughly 25% of the total mass of most plants.  Suppose that by 2017 we achieve Bush’s goal of 35 billion gallons of ethanol per year.  Since many experts put the maximum corn ethanol production for the US at around 15 billion gallons, this means that roughly 20 billion of these gallons will need to come from cellulosic sources.  At 100 gallons of ethanol per ton of switchgrass (a huge simplification): 20 billion gallons/100 g/t*.25t lignin/t biomass = 50 million tons.  50 million tons *300 dollars per ton= 15 billion dollars/year.  Say that the only half of this lignin is able to be obtained, it is still a 7.5 billion dollar per year industry.  This is huge.  Of course this all depends on how much it costs to convert a ton of lignin from being worth $40/ton to $300/ton and the details in the article seem to be lacking here.

“Lin and his colleagues are trying to turn the resulting glycerol into a substance called 1,3 propanediol, or PDO, the base material for a substance used in upholstery, carpets, clothing and other applications. DuPont uses PDO to make its Sorona line of fabrics.  “For every gallon of biodiesel you make, you make a pound of glycerol,” said George Kraus, a professor of chemistry at Iowa State, where he is director of the Center for Catalysis and a collaborator of Lin. “A lot of people have been contacting us about burning it, and we say there have to be better uses.”  The price of glycerol, now 20 to 50 cents a pound, could drop as low as 5 cents a pound as biodiesel production increases.  Kraus said the higher quality glycerol made with the new process could command a much higher price. “What we see,” he said, “is an opportunity to make something that might cost 80 cents a pound.”  This isn’t exactly relevant to this site but it is interesting none the less.

Many believe that as more uses are found for what are currently waste streams from biorefineries, the economics of biofuels will improve.  Anyway, the article goes through many other examples like the ones I quoted and is definitely worth a read.

Cellulosic Ethanol from Rice Straw Plant Being Built in California

Ron Kotrba has written an incredibly interesting article for Ethanol Producer Magazine about a company which hopes to soon be making ethanol from rice straw in California.  Currently, California rice farmers must pay $25 to $45 per acre to have the rice straw baled and removed from their fields.  Colusa Biomass Energy Corp. (CBEC), the company which is currently in the process of building their first plant to process rice straw, has offered to take it off their hands for a mere $15.  There is a general understanding that once the plant is built CBEC will be removing the straw at no charge.

Rice straw has limited other uses since it has a very high sodium silicate content which is not palatable to livestock and is very abrasive for machinery.  CBEC intends to separate the silicate and use it as an extra revenue stream, selling it to a range of manufacturers.

The plant will be relatively small, processing “35,000 acres of rice straw into 12.5 MMgy of ethanol and 33 million pounds of sodium silicate.”  This is not necessarily a bad thing however as it will cut down on average transportation costs to the plant.  Generally 3.5-4 tons of rice straw can be collected per acre.

The amazing thing is that CBEC will be doing this with no federal or state money.  They have generated enough investor interest to fund their project via investment capital.   CBEC has been doing small scale research for years, it is only relatively recently that they hired Harris group, a respected engineering firm to do an analysis to see whether their research can be scaled into an economical, large scale, continuous process.  Harris group seems to think that this is doable, so the project is moving forward.

The actual process is described by the article to work as follows:

“We wash it, then introduce a mild solution of a strong acid then [which] hydrolyzes out the lignin and the hemicellulose,” Bowers says. “Then a second hydrolysis process occurs where we extract the cellulose from the remaining substrate.” He says the process whereby CBEC hydrolyzes the substrate, removing most of the lignin and all of the silica, is proprietary. “We have designed the hardware and the software to propel a reverse osmosis custom filtration device that we built to do the extraction,” Bowers says. “Through filtration, we separate the silica out and precipitate it as silica sodium oxide, and from the other side we pull out the lignin.” Once the lignin is dried down, CBEC plans to use it as boiler fuel. The company’s sales forecasts indicate the ability to retrieve 34-cents a pound from the more than 33.5 million pounds of sodium silicate, a versatile compound used to make everything from micro-electronics to toothpaste.  Once the cellulose and hemicellulose are separated from the lignin and silica, fermentation begins. “Our fermentation will look just like the corn guys’,” Bowers says.”

I hope that they don’t look exactly the same, if CBEC tries to break down the cellulose like corn starch (using amylase), they are going to be sadly mistaken.  They will be needing to use cellulase which as far as I know still acts more slowly than amylase and will be considerably more expensive.  I wonder whether they are going to just take on the cost of the cellulase or if they have figured out a plan for this expensive item too.  I would be extremely interested in the details of how exactly their second hydrolysis process works as well.

“We’re considering separate five-C and six-C lines”–and how do they propose to enzymatically break down the hemicellulose? I could be very mistaken but as far as I know there is not yet an economical way to break down hemicellulose since hemicellulose consists of so many different sugars.  You would need a multitude of enzymes each being unique to the sugar that they attack.  They could break down the hemicellulose via acid hydrolyis however but that is questionably economical.

Anyway, the company hopes to expand to 11 refineries by 2012 located in California, Texas, and Arkansas.   In the long term they see a lot of potential for global expansion since rice is such a staple crop world wide.  Whether they succeed or not, I guess we will have to wait and see.

Wood to Wheels, Michigan Tech’s answer to “Turning down the carbon pump”

With all of the recent press regarding Mascoma’s new wood based cellulosic ethanol plant that will be built in northern Michigan and the assistance that they are receiving from Michigan’s universities, I thought it would be interesting to write about one such program that will be assisting them. The Wood to Wheels program at Michigan Tech is “a graduate enterprise in sustainable transportation utilizing fuels and co-products from forests and other biomass sources.” Basically Michigan Tech is trying to tackle many issues involving creating a sustainable means of fulfilling our nation’s energy requirements.

The four main objectives of the program are to “improve bioprocesses that will utilize woody biomass, improve forest management and apply biotechnology to increase forest biomass productivity/utilization per acre by 65%, demonstrate forest land management, fuels production, and vehicular technologies that close the carbon cycle and stabilize atmospheric CO2 levels, and optimize powertrain technologies that reduce fossil fuel consumption over the life cycle by up to 100% in vehicles that use these technologies.”

In their effort to improve the bioprocesses, wood to wheels participants are working on a number of things. They are trying to genetically enhance cellulase enzymes, take advantage of peptidomimetic modification of cellulase activity, genetically enhance the yeast organisms so that a higher yield of sugar can be converted into ethanol, and improve efficiency of the entire process to reduce waste.

The Wood to Wheels forest resources initiative seems to be slightly more general. They are researching wood formation, defense and fitness (of the plants), natural variation, and carbon sequestrations. Researchers are also looking at metabolite profiling and chemical fingerprinting.

From the Wood to Wheels site, the objective of their efforts to improve engine and vehicle designs is as follows: “Develop technologies that will optimize engines for the use of ethanol and ethanol/gasoline mixtures for vehicles including hybrid applications.” They hope to increase vehicle efficiency by 50% and improve the cold start for E85 to E100 ethanol vehicles.

Finally, their assessment initiative looks at broader issues. From environmental effects, to policy analysis, to huge life-cycle analyses.

Anyway, this program looks to be very promising and should be a boon to Mascoma’s efforts in the state.

Ethanol From Plant Waste

The author of this article is definitely a supporter of enzyme based cellulosic ethanol. He makes several points. The first is that neither ethanol from corn, nor the thermo chemical hydrolysis cellulosic ethanol production technique is sustainable. Both of these are not useful because of efficiency issues –they do not have the potential to compete with enzyme based cellulosic ethanol once the process is perfected. He does a good job presenting some of the reasons why we are currently having issues with enzymes being useful, and talks about how we are going to overcome them. He does believe that the goals presented by the department of energy are achievable, but that we need to be careful with how we spend money so that we do not waste. The answer to the enzyme problem will be through genetic mutation of either our source of cellulose, or through modifying our enzymes.