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By Robert Rapier on Aug 20, 2012 with 21 responses

Why Sugarcane Bagasse is the Most Promising Pathway for Cellulosic Ethanol

In last week’s Energy Trends Insider (ETI) I explained Why Sugarcane Bagasse is the Most Promising Pathway for Cellulosic Ethanol. In addition, I answered a reader’s question about Ethanol’s Role in Rising Gas Prices and whether that increases the chances of a partial waiver this year of the Renewable Fuel Standard. As we have done previously, we would like to share a story from ETI with regular readers of this column. Interested readers can find more information on the newsletter and subscribe for free at Energy Trends Insider.

Why Sugarcane Bagasse is the Most Promising Pathway for Cellulosic Ethanol

The history of cellulosic ethanol is a lot longer than most people probably realize. In 1819, French chemist Henri Braconnot discovered how to break cellulose down into component sugars by treating biomass with sulfuric acid. Once sugars are released from cellulose, the solution can be fermented to ethanol in processes that are very similar to those used to produce corn ethanol or sugar cane ethanol. Regardless of the way the sugars are released, processes that produce ethanol from cellulosic sugars are collectively categorized as cellulosic ethanol.

The Germans first commercialized cellulosic ethanol production from wood in 1898. The technology was commercialized in the U.S. in 1910, when Standard Alcohol Company built a cellulosic ethanol plant in South Carolina to convert lumber mill waste into ethanol. Standard Alcohol later built a second plant in Louisiana. Each plant was capable of producing over 5,000 gallons of ethanol per day from wood waste, and both were in production for several years before being idled for economic reasons.

Many subsequent attempts were made to commercialize cellulosic ethanol during the 20th Century, but there were huge challenges in developing cellulosic ethanol as a cost-competitive energy option. Because of the extra steps involved relative to corn or sugarcane ethanol, capital and operating costs are higher for cellulosic ethanol than for ethanol derived from simple sugars. But the ongoing attraction of cellulosic ethanol is the potential to utilize waste streams that are cheap or even negatively priced to produce the ethanol. Therefore a number of companies continue to work toward commercialization.

I have long felt that the residue from the processing of sugarcane — bagasse — seems to be the lowest hanging fruit for the production of cellulosic ethanol (better even than municipal solid waste). There are residual sugars in the bagasse, and it is washed, pulverized, and already delivered to a factory. In fact, even after using some bagasse to power their plants, sugar plants struggle to dispose of excess bagasse. Thus, the economics of bagasse versus purpose-grown crops for cellulosic ethanol production should be significantly better.

Some companies have focused on the potential of bagasse for ethanol production.* In 2008 Verenium announced their intention to build a bagasse-based ethanol demonstration plant in Louisiana and a commercial plant in Florida. Those plans ultimately did not pan out, and Verenium sold their cellulosic ethanol business to BP.

But Blue Sugars Corporation (previously KL Energy) recently reported that they had achieved the major milestone of claiming the first cellulosic ethanol tax credits under the RFS2 for a 20,000 gallon batch of cellulosic ethanol produced from bagasse. I have confirmed with Blue Sugar officials that this is the 20,069 gallons of cellulosic biofuel that the EPA lists for April. (No cellulosic biofuel RINs are reported by the EPA in May or June).

Cellulosic ethanol commercialization still faces a number of challenges. Capital and operating costs are expected to remain higher than for corn ethanol producers, and even they are currently struggling with low margins. The ethanol market also faces the hurdle of the blend wall, which makes it difficult to expand domestic production without increases in E15 and E85 consumption, and/or ethanol exports.

Nevertheless, I believe that those focused on waste feedstocks have the greatest chance of successful commercialization of cellulosic ethanol. I would put my money on bagasse as the most attractive feedstock, followed by municipal solid waste and agricultural residues.

*Beyond ethanol, Solazyme has reported production of algal fuel from sugars derived from bagasse.

Link to Original Article: Why Sugarcane Bagasse is the Most Promising Pathway for Cellulosic Ethanol

By Robert Rapier

  1. By nick on August 20, 2012 at 12:21 pm

    longtime follower, first time commenter

    i see no mention of eroei…do you have a figure ? many believe anything below 5-8:1 will not run any modern society and many biofuels are actully -ive?

    part 2 how important do you think the measuring of eroei is for a fuel source?

    • By tennie davis on August 20, 2012 at 6:00 pm

      Nick, I can’t speak for R squared, but here’s my opinion.

      EROEI is way overrated, what’s important is cost. If input energy is cheap, and the output energy is valuable (transportable and energy dense), EROEI becomes somewhat irrelevant.

      • By nick on August 21, 2012 at 4:33 am

        interesting view.

        if we are talking about trying to create an energy source its clearly useful if you get more energy out than you put in. unless you are a bankster they follow that plan !!

        • By tennie davis on August 21, 2012 at 6:41 am

          Nick, we’re not necessarily talking about “creating” an energy source, the source of almost all energy comes from the sun, this includes fossil fuels, and agriculture. You can’t get more out than you put in, and it doesn’t matter how much energy you  put in, what does matter, is the utility, or usefulness, of the end result, I don’t think banksters have much to do with it. But since we’re on the subject of “bankster bashing”, have you ever put money in a bank, or do you just hide it under your mattress;)

    • By Robert Rapier on August 21, 2012 at 4:48 am

      i see no mention of eroei…do you have a figure ? many believe anything below 5-8:1 will not run any modern society and many biofuels are actully -ive?

      Hi Nick,

      Sorry for the slow response. I am traveling at the moment.

      I suspect that the EROEI for cellulosic ethanol producers is not that good, but it is likely better for sugarcane than for the other options. I don’t really have an idea of what it might be, but I doubt it is higher than 5/1. My main point is simply this: To the extent that cellulosic ethanol has any chance of succeeding, bagasse should be the best option.

      As far as the importance of EROEI, it is important for understanding the sustainability of a particular option, but that won’t dictate whether a particular option is pursued. If a company can turn cheap natural gas into more valuable liquid BTUs, they may do that even if the EROEI is poor. But a low EROEI may mean that the process is worse than just burning the fossil fuels directly.

      Cheers, RR

      • By nick on August 21, 2012 at 11:35 am

        the reason they are going through the process is to create a source of usable energy hence i believe the eroei is important, especially in aggregate we cant have all the energy producing companies concentrating just on profit or they will not produce any net energy to run society. that said i agree this may well be the best of the biofuels other than future algae systems 

        • By Alice Finkel on August 21, 2012 at 4:23 pm

          Nick, EROEI is one small piece in a very large and complex puzzle.  It is not the key piece of the puzzle by any means.  You will not believe this, but the concept of EROEI is more of an obstructive fixation than a conceptual empowerer.  It clogs the thinking process rather than facilitating it.  The sooner you outgrow that thinking trap the better.  But as I say, you will not believe these words of advice, as kindly as they are intended.

          • By nick on August 22, 2012 at 1:55 am

            If you can explain why net energy is not key i am happy to listen. Charle hall got the idea from nature where its crucial…just dont tell me money will sort it out !!!!

  2. By Optimist on August 20, 2012 at 2:20 pm

    Because of the extra steps involved relative to corn or sugarcane ethanol, capital and operating costs are higher for cellulosic ethanol than for ethanol derived from carbohydrates.

    On a technicality: cellulose is also a carbohydrate. Chemically it is identical to starch. The mere difference in orientation of the monomer-to-monomer link is what makes cellulose so much harder to hydrolyze.

    You may want to replace carbohydrates with starch or sugars.

    • By Robert Rapier on August 21, 2012 at 4:43 am

      You may want to replace carbohydrates with starch or sugars.

      That’s a good observation.


    • By Alice Finkel on August 21, 2012 at 4:26 pm

      In the nutrition field, they refer to cellulose as an undigestible fibre.

      But try telling a termite that.

      • By P.M.Lawrence on September 15, 2012 at 7:03 pm

        Not even termites can digest cellulose. Even they have to put it through a processing stage, which they do by bringing the raw material back to their mounds and putting it in fungus gardens.

        Related, I somewhere saw an article speculating that coal was only formed in a period before fungi had evolved the ability to cope with all the cellulose, lignin, etc. from dead plants; until then, enough material remained to be trapped geologically, but not since then. Apparently even fungi had to do a lot of development to be able to process all this reasonably well.

  3. By stan on August 21, 2012 at 9:37 am

    Conventional farming is not an efficient method of producing ethanol…….period.

    Only a VERY intelligent and analytical individual would be able to determine how to go about this correctly……and I’m sorry to say, there are most likely no people right now who are good enough at it, if you look at what a total mess has been made of the world’s economy over this issue. But here’s a starting point……you know thos evil people at Monsanto who make GMOs? Well, there is a country… can google for which one it is……who gets all their cellulose without about 90% of the farming expense, OR the pollution it causes…..for FREE. The “crop” can grow faster than anything else on the planet..up to 3 feet per day…and it’s genetics can be added to many other plants………it’s called BAMBOO..we now have skyrocketing food prices because our so-called experts are dangerously stupid.

    • By Optimist on August 22, 2012 at 12:59 pm

      Stan, you are implying that there are efficient ways of producing fuel ethanol. I’d love to know what you base that opinion on.

      Ethanol is a terrible fuel. Period.

      At least the military-industrial complex will save biofuels with their drop-in renewable fuels. If they can get it past the prostitutians in Washington, that is.

  4. By Ben on August 21, 2012 at 4:26 pm

    EROEI is key and, unless you’ve figured out how to line up feedstocks that are cheap and long-term, well, you’ll need to keep tabs on conversion efficiencies.  As the supply/demand constraints become increasingly apparent in the months ahead, the issue of sustainability (economics accommodating regulatory requirements) will likely dictate that some formula involving EROEI will figure into the federal government’s regulatory and fiscal (tax) treatment of energy production/use.   Such an eventuality is kinda the sine qua non of the type of analysis that Charles Hall and colleagues find themselves promoting in recent days.   Some of this may not be particularly motivating to free market-types (I tend to be more not less sympathetic to market mechanisms), but such bottom-line performance standards are coming down the pike.   It will  sound a death-knell for a range of ineffcient platforms in the bioenergy space that trade on political connections and temporary subsidies.  Wow, perish the thought that we might actually require demonstrable output before distributing largess via the public treasury.   Why, that might suggest that we’re actually getting serious about breaking up the pie-in-the -sky biofuels con game that we’ve witnessed for nearly a generation.   Don’t get me wrong, biofuels will continue to have a place in the overall energy mix, it just happens to be a little further towards the back of the energy efficiency bus.  And it certainly doesn’t belong anywhere near the driver’s seat (all these yellow buses running around the Washington suburbs this afternoon sort of inspires the analogy–good luck to all all the students and congratulations to the surviving moms and dads! :)











    • By Optimist on August 22, 2012 at 12:57 pm

      EROEI is key…

      Nope. Profitability is key. Now, it is true that if you have terrible EROEI, you are unlikely to be profitable, but if you are in the ethanol business, there is always Uncle Sam to take care of you.

      I think RR has tried to make this point (on multiple occasions) before: not all kWh are created equal. One kWh of electricity is more useful than one kWh of coal. Hence we burn several kWh of coal to create one kWh of electricity. EROEI is to blunt a tool to measure the added value of electricity compared to coal.

      That’s the beauty of a free market. You get a pretty good idea of how those numbers shake out. Of somebody thinks the numbers do not reflect reality, well maybe there is an opportunity to enter the market, set things straight and get a nice profit for your troubles.

      In the current political market it is worth pointing out that free markets do not occur spontaneously any time Uncle Sam leaves the room. Quite the opposite. You need Uncle Sam to set the rules and enforce them. Keeping the playing field level is a full time job. Unfortunately, Uncle Sam has been doing a terrible job lately, doing more to trying to tilt the field to his favorite constituents (and lobbyists). America’s political system is slowly failing, but that’s a different topic altogether.

      Wow, perish the thought that we might actually require demonstrable output before distributing largess via the public treasury.

      Yeah, right: I trust farm state senators to look at the data objectively before making up their minds. Sure. ROFLOL!

      The better proposal is again our friend RR’s: pay for kWh delivered, and nothing else. Pay on a sliding scale where the first X kWh get more money, until eventually you get nothing extra. Find your own private investors. Let’s see how many of them fall for that slick PowerPoint presentation…

  5. By Ben on August 24, 2012 at 2:57 pm

    Optimist really does help make some of my points without much of a hint of agreement.  That might require a measure of humility–something in short supply on the web and in politics:)    Nonetheless, the endorsement of free markets and defence of responsible governance is always welcome.   I’m much less sanguine re: contributions out of the military industrial complex for biofuels.  I think General Eishenhower got it right in the cautionary notes sounded in his presidential farewell address to the nation.  I suspect the Defense Production Act and it’s Title III projects will provide ample eveidence of that in the days ahead.   Conservative the Pentagon is not.  Alas, all bureaucracies are wasteful and the bigger they are……

    RR’s blogspot is always worth the read and worthy of discussion.  This is made all the more gratifying, as he is a gentleman.

    Ben (enroute to the Sahel)




  6. By Russ Finley on August 25, 2012 at 6:09 pm

    I will wager that the return (both monetary and EROEI) is higher when the bagasse is burned on site to create heat for processing or electricity. Converting it to a liquid fuel before wasting most of its energy in an internal combustion engine seems less efficient.

    I saw a commercial the other day from Shell Oil. It was hawking their investments in sugarcane ethanol–not corn ethanol …interesting.


  7. By Ben on August 26, 2012 at 4:30 pm

    Yes, in situ recovery of waste feedstocks adds markedly to cost/energy efficiencies;  savings results from optimizing EROEI and achieving increased profitability; this  will remian the private sector’s holy grail even  as the government has an obligation to look at profitability even as it contemplates larger societal issues–security and evironmental protection being primary among so many others.   Many of my project financing associates here at home and abroad join in the view that public policy is inching along toward a more sophisticated understanding of how private capital allocation interrelates with the strategic objectives of sustainable economics; this nexus is where energy effeciencies plays a central role in determining the potential and actual efficacy of ventures in these most turbulent of times.

    Thanks, Russ, for pointing out this particular example.  I like your balanced approach to saving the planet one initiative at a time.  What’s that line about “if everyone does a little………?




  8. By Optimist on August 27, 2012 at 5:05 pm


    FWIW, I have no problem being humble, AFAIK. Obviously it’s a subjective opinion ;-)

    On a related note, I find your posts very sensible, and hence worth responding to. You even have a knack for staying on topic, in spite of my ascerbic style.

    There is a lot of irony in my comments on the military-industrial complex and their efforts to save renewable fuels. Nonetheless, I stand by my comments. Washington is literally acting like a drunken sailor, urinating endless funds into ethanol, mandating its use, and refusing to acknowledge that, like everything else, ethanol has its limitations. Cellulosic ethanol = pixie dust, inside the beltway.

    The military-industrial complex, by comparison, is looking at drop-in replacements. Poof! goes all the issues with the blendwall, storage, transportation and changes needed to ICEs. Next, the are closely following the strategy outlined by RR: paying for delivered product, rather than generous loan guarantees from which Vinod Khosla and others have benefited so handsomely. (Won’t you know it, that company went bankrupt! But here’s an even better opportunity!!!) Sure, they are paying outrageous prices right now, but they are leaving a lot of doors open to current and future innovation. In stark contrast with Washington’s ethanol-only (hic!) policy.

  9. By galonga on March 24, 2014 at 7:06 am

    To speak to americans about bagasse when they have not ever seen a sugarcane plant is a waste of time. They are too stuck with the notion that ethanol only comes from corn and that therefore absolutely all ethanol known to mankind is evil.

    The author of this post is wasting his time trying to expose something new to the american brainwashed public who thinks it knows it all when it comes to biofuels.

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