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Direct Ethanol Fuel Cell (DEFC) & Farm Compatibility

image credit: They are my own photos edited using Canva
Allan Jay Martirez's picture
Chemist, RISAL

I am a biofuel enthusiast. My dream is to convert farm waste to bioethanol be fed to spark-ignited engines to provide power for farm operations. I also wish to be able to collect the exhaust...

  • Member since 2023
  • 7 items added with 1,047 views
  • Mar 16, 2023

Observing the rice harvest, I noticed that farm residues comprise the major bulk of materials in the farm. Riceland farm residue are rice straws, rice hulls, leaves and other plant parts. Except for rice hull, the farm residues after rice harvest are either burned or left to rot to fertilize the field. Rice hull is the most stubborn of all the rice farm residues because it can’t be fed to livestock, nor can they be left to rot in the field. At least to a rice farmer, if anyone would take their rice hull after milling, they will appreciate it.

There are several studies that discuss rice hull pretreatment that could render rice hull apt for saccharification by enzyme cellulase. But those pretreatment methods require equipment that are a little more involved and thus pricey, let alone the operational cost entailed in using them.

Rice hull are sold charred in gardening supplies as fertilizer and sometimes a anchor for hydroponic farms. The heating requirement for charring rice hull is energy intensive and polluting. If rice hull can be turned to glucose without complex and expensive pretreatment methods, it is a real bonanza for those who want to try decentralized farming, using farm residue to fuel their spark-ignited engines like electricity generators which can in turn, run electric irrigation pumps. Perhaps it can also provide lighting and some power for farmhouses too. And this application is not limited to rice. Perhaps this is applicable to wheat farms as well.

The cellulosic grain seed hull will react with a copper based chemical solution called Schweitzer’s reagent and readily solubilize the cellulose into the solution. The residual mass is too frayed and soft making them ready for direct enzymatic treatment. The remainder are mostly silica that might be valorized for silica refinement which has an application as desiccant among other things.

The cellulose that are isolated from the Schweitzer’s reagent after neutralization can be washed thoroughly and be enzymatically treated with cellulase in  buffer solution and kept in optimum condition. Several days after, glucose will be produced from it and it will be decided whether to refine the glucose or directly ferment them to ethanol. Distillation follows which is easy for everyone. The moonshiners’ skill will come into play here. After three passes in the distillatory and at between 95 – 98% ethanol, your fuel from farm residue is ready.

For more details about the use of Schweitzer’s reagent, kindly watch my video: 

The picture of the propeller is from a STEM toy we purchased from the Czech Republic and delivered to Manila. It is a Direct Ethanol Fuel Cell or DECF. The DEFC technology is not as developed as the hydrogen fuel cell as the complete oxidation from ethanol to CO2 has not yet been perfected. The farthest reached in this oxidation is until the formation of acetic acid which can be purified or used as neutralizing agent for cellulose production using Schweitzer’s reagent. 

I’m not a native speaker so please excuse my accent and grammatical errors. Please proceed with caution if anyone will try the technique depicted in the video as they are not peer reviewed technic although I personally did the activities in the video. Thanks

Rick Engebretson's picture
Rick Engebretson on Mar 17, 2023

I wish I could thank you enough for your shared thoughts and efforts. I had hoped to reply with insightful, useful, helpful related information. But I just dug out my old thesis, blew off a lot of dust, and realize I have a lot to re-learn to contribute to a REAL SCIENTIST that you are.

I did my grad research in the Laboratory for Biophysical Chemistry at the University of Minnesota in the late 1970s-early 80s. I was paid to build and use a very high pressure (to over 100,000 psi) Hydrogen (tritium) Exchange Kinetics in proteins contraption. While drilling holes in steel I took a lot of advanced classes in computers, biochemistry, genetics, solid state physics. I saw a lot of physics in biochemicals many didn't. For example, the heme group of hemoglobin is a current loop with iron in the center ie; an electromagnet, and oxygen is the only magnetic gas in the air. Also, the peptide alpha helix structure has a huge dipole. Starting reading my thesis now I re-learned the Xray protein-water-crystal structures might be inside out from fat membrane proteins. After the pressure stuff I got to try my electric field and ultra-sound hydrogen exchange kinetics experiments.

So I totally agree with your ultimate goal of farm waste/fuel cell generation. But I think we are stalled out in REAL ENERGY SCIENCE development. A good example after my fancy work was proposing a "recycled plastic livestock septic tank" to recycle trash and provide fuel, fertilizer, sanitation to local dairy farms. Today, the landfills are full and the dairy farms are gone. But government still pushes solar panels and windmills using borrowed money.

So I share your urgency, and believe do it simple and do it fast. Car electric generators produce enough for my average use, about 1KW, roughly 2 horsepower. At one time methanol, wood alcohol, was favored, and ran race cars.

So I leave it to you, YOUNG SCIENTIST. We need you.

Allan Jay Martirez's picture
Allan Jay Martirez on Mar 20, 2023

How are you doing Sir? I'm truly humbled with your kind words and at the same time, extremely excited with your ideas. I started doing my YouTube channel Sir to show the young people that conceptually, a green alternative fuel is possible, and it was up for them to fill in the gaps. If it is ok and convenient to you Sir, I would like to have a copy of your thesis. I believe it is a good read.

By the way Sir, I'm starting to believe that people with the same goals meet one way or the other. When you mentioned about plastic and septic as source of energy, I'm really thrilled because I have been imagining it to be my phase 2 after I get through my phase 1. I imagine harnessing methane and ammonia from livestock manure and ammonia from urine. The methane could either be burned directly or reduced to methanol to be converted to sodium methoxide for biodiesel production. I imagine I can scrub the tailpipe emission of CO2 by either compressing them into tanks or reacting them with ammonium hydroxide to produce. CO2 might be used for plastics pyrolysis. 

My phase 1 Sir is to settle in our province and start a backyard, low budget rice farm residue to ethanol project to produce small electricity using generator. Then I'll try to compress the CO2 emissions from the generator into cylinder tanks. Now this part seems dreamy because I haven't tried it before. But the next part is a bit exciting because I plan to establish a stoichiometric ratio of CO2 feed compared to plant growth in a small greenhouse.  I want to make an actual case in point that biofuels are not as offensive as what some clean energy lobby group thought it is. I chanced upon a LinkedIn post that some people labelled biofuels as a "criminal" for using food as feedstock for biofuel production while the use of it emits CO2, this was aimed at some bioethanol plant somewhere in Europe. I want to prove that the biofuel CO2 emissions are carbon neutral in this perspective. And for bioethanol alone, there are more cellulose than the readily fermentable food stuff. I will keep you posted on this Sir because with your vast experience and superb grasp in the foundational science behind this all, I know that you can guide me to the right direction.

Thank you, Sir.

Rick Engebretson's picture
Rick Engebretson on Mar 21, 2023

My name is Rick, please. And I don't know how you and many others learn and communicate so well in my only language. So start out giving yourself a LOT of credit. My thesis was written in typewriter days, like my learning was done in thick book days, and much of my promoted science is now reality, so you have a new starting point even though new challenges. History happens.

As you describe your ethanol inquiry in this post, you already know you have plenty of cellulose that is sloppy and often expensive to use well. And you know ethanol fuel cells are imperfect at best. Please consider from Minnesota USA that a Biophysical Chemist has some little experience with the topic. Biochemical structures are extremely complex, and food requires complex cell biology synthesis. Essential nutrients like protein can't be made in a laboratory beaker. One reason is the symmetry properties of amino acids must be exclusively "left handed" (not right handed) to fit into the cell biology molecular assembly machinery. Similarly, DNA is clearly not just a "good enough" assembly of nucleic acids. These vital complex nutrients can now only be made in sufficient quantities feeding simple nutrients like sugar to simple organisms like yeast and harvesting the yeast to feed up the food chain. Ethanol was simply a waste product, and proposals were requested to figure out what to do with it. Luckily, Henry Ford had already considered ethanol fuel before gasoline dominated. I had this ethanol process at least as wrong as everybody else, and I had more reasons to understand it from the start than I can list. So, like you say (as a REAL SCIENTIST), don't take my theories as fact.

To reply to your "on farm fuel cells" post I dug out an old briefcase I thought might contain a booklet I got from the "National Rural Electric Cooperative Association" promoting such a system using methane. Instead I found materials from a tour of the stationary fuel cell installation at the 934th Airlift Wing in Minneapolis, sponsored by some great US energy and US DOD leaders in 1999. Your science insight and projection are excellent, except for your ethanol hangup.

I think a good read for you is the earlier link to 

describing syngas from biomass. A remarkable feature of this process is DIRECT STORAGE OF SOLAR ENERGY into the product fuel gas. Nothing beats it for simplicity and green friendly. And I think your chemistry talent is well suited trying to play with the syngas.

It is surely the case excess atmospheric CO2 needs consideration. But it is also the case 8 billion people need quality food and modern energy. Only agricultural innovation can help do it all.

Your friend, Rick.

Allan Jay Martirez's picture
Allan Jay Martirez on Mar 22, 2023

Hi Rick. I'm glad to have a friend like you. Thanks for all your inputs. And you're perfectly accurate about my ethanol hung-up. It's a spot on. It's something in my personality that when I get attached to an idea I cling on to it. Time to move on I guess.

This is the first time I learned about CSP and I truly appreciate this. If I remember correctly, I chanced upon a YouTube video before that briefly described this process. I didn't know it is called CSP. It was about a project in Tunisia to provide power to Spain using mirrors to create steam to power an STG. The biomass-CSP tandem is truly best suited in farms because where biomass and animal manure could be fed to biodigesters. The CSP could perhaps power the heating requirements of the biodigesters while the biogas is being produced. This is a more direct way to deal with the biomass with the least steps to produce farm electricity. The CO2 will be used in greenhouse and seedling nursery. A perfect idea. It does not require rare earth too. I'm sure I can't afford it for now, but the biodigester is a reasonable project to start with. I'll refer to the link you sent me to get more ideas.

As for my communication style, believe me, there are many more in the Philippines who are way better than me. Infact, mine is mediocre compared to them. English became our second language because we became a US Commonwealth territory well into the 1950's. The Americans built the modern Philippine institutions and most of the administrative practices survived until today. Our state university was founded by the Americans. Our premier military school was founded by General Arthur McArthur, his son became the first Field Marshall of the Philippine Army. The Philippine Historical Institute erected a statue for General Douglas McArthur and his party to commemorate his return to liberate the Philippines in the 40s. One avenue in Manila is named after Howard Taft, the first Governor General after the Spanish rule. I grew up watching Bugs Bunny and Sesame Street and The Three Stooges. The medium of instructions at school is English. 

Thanks my friend.

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