Direct Ethanol Fuel Cell (DEFC) & Farm Compatibility

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