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New simple, energy-efficient process for the direct production of renewable diesel from biomass waste

Corma
Non-edible carbohydrates are converted to renewable diesel-range liquids via two consecutive catalytic steps. Credit: Wiley-VCH, Corma et al. Click to enlarge.

A team at the Universidad Politécnica de Valencia (Spain) has designed a new simple, energy-efficient process (that also does not require any organic solvents) for the production of renewable diesel from biomass waste. A paper on their work is published in the journal Angewandte Chemie International Edition.

The process converts 2-methylfuran (2MF)—which can be obtained from biomass wastes such as corncobs, oat hulls, bagasse, and sunflower husks—into diesel-range hydrocarbons through two consecutive catalytic steps that involve hydroxyalkylation/alkylation and hydrodeoxygenation, with an overall yield of 87%.

A number of routes have been and are being developed for the conversion of biomass into renewable fuels, including (but not limited to):

  • Gasification of biomass followed by Fischer-Tropsch synthesis;
  • Fast pyrolysis and upgrading of bio-oil;
  • Hydrolysis of biomass followed by the fermentation of the sugars by genetically modified microorganisms to hydrocarbons;
  • Dehydration of hydrolyzed sugars to 5-hydroxymethylfurfural (HMF) or into furfural (FUR) when starting from hexoses or pentoses, respectively, followed by aqueous phase processing;
  • Production of γ-valerolactone from biomass-derived carbohydrates via levulinic acid, followed by decarboxylation to produce butene and CO2, the former then being oligomerized to octenes and hexadecenes in a second step.

This list of processes to produce second-generation biofuels can be further expanded, but the extent to which one of these technologies will play an active role in the future biofuel industry will depend on economics, energy efficiency, and environmental issues. Surplus energy consumption and process limitations can be detected in most of the processes proposed to date. For example, the excessive cleavage of carbon–carbon bonds and subsequent reformation leads to energy losses. Extractions of products with organic solvents are energy and cost-intensive steps that change, to the worse, the overall energy balance of the process. Organic solvents as reaction medium should be avoided, as they enlarge process volumes with a negative impact on process economics and environment. A crucial point for the optimization of the overall process economics is the perfect overlap of the boiling point range of the product mixture, with diesel range C9 to C24 hydrocarbons.

By considering all of the above described limitations, we have designed a sustainable process, based on reactions other than those reported before, which involves hydrophobic intermediates and produces nonpolar alkane products suitable for high-quality diesel fuel. This strategy implies that, owing to the polarity of the products, water separation by distillation is not required, but an automatic, energy-neutral physical separation of (intermediate) products from water will occur reducing energy consumption in the process.

—Corma et al.

The first step is the conversion of biomass into furfural—an established industrial process. In an adaptation of another current process, furfural can be converted with high selectivity into 2-methyl-furfural (2MF), a ring consisting of four carbon atoms and one oxygen atom, with a side chain consisting of a methyl group (-CH3).

Three molecules of 2MF are linked together. This requires water and an acid catalyst. This reaction causes one third of the rings to open and each to link to two other rings (hydroxy alkylation/alkylation). The aqueous phase, which also contains the catalyst, separates from the organic phase, which contains the intermediate product, on its own. It can easily be removed and the catalyst recycled. In a second reaction, the two other rings must also be opened and their oxygen atoms removed. This reaction uses a special platinum-containing catalyst (hydrodeoxygenation).

In the end we obtain 87% of the diesel fraction in the form of branched hydrocarbon chains with nine to 16 carbon atoms. This is the best yield reported in the literature thus far for biodiesel synthesis.

—Avelino Corma

The process is very stable at lab levels (more than 140h). Gas-phase and lower molecular weight byproducts can be used to produce heat. The resulting renewable hydrocarbon liquids are of excellent quality (cetane number 71, pour point -90 °C) and can be mixed directly with conventional diesel fuels.

The process described herein opens new routes for producing high quality diesel from waste biomass. Indeed, we can envisage two other processes that we are currently working out in which 5-hydroxymethylfurfural (HMF) and 5- methylfurfural derived from hexoses are reacted with 2MF in the presence of an acid catalyst under similar conditions as employed before for butanal and 2MF.

—Corma et al.

Resources

  • Corma, A., Torre, O. d. l. , Renz, M. and Villandier, N. (2011) Production of High-Quality Diesel from Biomass Waste Products. Angewandte Chemie International Edition, doi: 10.1002/anie.201007508

Comments

creativforce

Biomass waste? Isn't soil being depleted at least as quickly as fuel?

ExDemo

ceativforce,

Shssh! Quiet. The eco-loons are on a run. Since they no nothing, don't ruin their day with petty questions about depleting the soil by utilizing al the components of farming and returning nothing to the soil.

This development is surely as great as the perpetual motion machines they propose to create by oxydizing (burning) fossil fuels into Carbon dioxide gaining energy of 50% or less as useable work.

Then the fools believe eco-charlatans, who tell them they can reverse and un-oxidize CO2 to re-constitute fossil fuel. All at a net release of useful energy in both directions.

Just like your father told you he walked 20 miles to school every day. Uphill! Both ways!

After they spend prodigious amounts of government taxpayer funds to do so, they will return to their favorite activity of constantly encountering the Law of Unintended Consequences. The eco-boodlers will say it was overlooked that you can't get back out what you put in, but they are working on reversing Entropy, whatever that is. Merely spend some more money, which the eco-loons will cheerfully support doing.

Let the eco-Loons who know no Science, be what they are ... Loons.

Henry Gibson

Before coal was used, one of the first iron producing areas of Germany which made one of the first iron water pipes, used about 80 percent of its land area for the coppicing of wood to make charcoal for the furnaces. There was not enough remaining agricultural area to supply food for the population so when the tree growth schedule allowed it, crops were planted among the trees and cattle grazing was done around the trees after the trees grew too big for the cattle to eat. People had to bake their bread in community ovens to save on fuel.

Even with the full care that that area gave to coppicing, from before the time of Columbus, it is doubtful if there would be enough fuel to run all of the computers now in use in the area. Even without wasting much of the energy by making charcoal out of the wood. ..HG..

Henry Gibson

It has been a very long time since I first read Angewandte Chemie.
In case any of you are worried that I am getting forgetful, I am, and I will add that any biomass can be converted to food and there was a prior article about how enzymes were newly discovered in cattle that help them do it. Prior chemical and other treatment of ordinary cattle fodder will even improve on this. Ethanol is, of course, a useful food even if it is made from fossil fuel or cellulostic biomass.

My favorite method to think about of converting biomass to food, is to convert it to CO, CO2 and hydrogen and feed the gases to to organisms that use it to make ethanol. In the USA at least, the FEDS test drinking alcohol to see if it has enough C-14 radioactivity to have come from biomass, as fossil fuels and petro-ethanol have very little Carbon 14. Corn ethanol factories could make a lot of money by feeding CO and H2 made from natural gas, LPG or even coal to their organisms. If they use CO and H2 made from grass and logs the Geiger counters will never rat them out.(reveal them) ..HG..

danm

Most bio-mass waste is not returned to the field today. Much of it turns into pollution, so turning it into something useful is better.
For example, scramento valley rice husks were burned for decades, resulting in air pollution. I have friends who developed asthma (adult onset) from this.
Soon this well be turned into biofuel instead.
I used to live in the florida orange groves and witnessed the pollution from orange peels from local orange juice factories. They never dumped these back on the orange groves (as the first 2 commenters imply).

Nick Lyons

@danm: Right on.

In urban areas, huge amounts of green waste and other biodegradable waste goes into land fills, where it decomposes, releasing methane, etc, which is often flared off. Turning this waste stream into diesel fuel replacement is a great idea.

Alain

Depletion of soil is only for a small part because of biomass removal, but mostly because of tilting and erosion and some mineral and nitrogen removal (which can easily be restored). The production of high-yield biomass will probably result in less tilting and erosion because of the use of fast-growing trees and perineal grasses (whose roots will be kept alive). Waste biomass is seldom returned to the fields, and even if it is returned, it is degraded very fast and turned into CO2. The use of perennial plants for biofuel could be an incentive to turn wastelands into economically productive valuable ecosystems. Harvesting the biomass from time to time can be done ecologically.
The timber and paper industry in norway has resulted in vast areas of (ecologically) valuable forests that used to be poor grasslands.

Account Deleted

To save our planet, we need to change our behavior, our consumption on oil and gas. High demand of oil will make Oil company explore more and more oil and gas, the we produce more heat and pollutions, damage our ozone.

Because when the needs of oil is decreasing, the Oil company will decrease their production. This is a good news for us, that we have a power to control oil production by changing our consumption behavior.

So, let's start to buy smaller car (engine), use electric power wisely. I think production renewable diesel from biomass waste will be a good idea.
Cheers: mobil Bekas

Coke Machine

Danm,

Obviously you have never heard of tropicana products where none of the orange goes to waste. After juice extraction, the remaining pulp and rind are mixed with water to remove remaining sugars and concentrated to make food quality ingredients. The orange oil from this concentration, as well as other orange essences and is either sold to chemical companies or the essences added to their concentrates they sell. That is why Tropicana orange juice (even the concentrate) is best OJ on the planet. After the extraction of the extra sugar from the squeezed orange (called pulpwash) the rind is sent to a feed mill where it is turned into cattle feed. The results of the cattle feed, are definitely returnable to the soil. No decent orange processor has dumped rind onto fields in decades. Before joinging the AF as a pilot I was a chemist in processing at Tropicana and after the AF, worked for the USDA inspecting their product. Believe me, there is NO waste.

danm

Coke, glad to hear of Tropicana's efforts. Your comments still help refute the 1st poster's claim...that using biomass for fuel depletes the soil.
If Topicana is not dumping the rinds back in the groves then the soil in the groves is being depleted, he would argue.
I agree with your point that making something valuable from the waste is OK.

Reel$$

"To save our planet, we need to change our behavior, our consumption on oil and gas."

Eddy, while this is true, I suggest you look at this video regarding your "save our planet" idea:

http://www.youtube.com/watch?v=eScDfYzMEEw

Engineer-Poet

You're citing George Carlin as an authority? A new low.

Reel$$

As a spokesman for common sense. Something millions of people admire. But is lacking in certain personality types.

HarveyD

Biomass may not (never) have the sustained capacity to feed 10+ B people and 10+ B vehicles + energy for industries, commerces, etc.

Solar, Wind, Nuclear +++ may have to come to the rescue.

Engineer-Poet

Common sense is only worth a crap when the phenomenon is part of every-day experience or at least similar to it. Quantum mechanics, molecular biology, even basic physics is way beyond the average Joe and they'll get simple questions wrong time after time.

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