There has been a lot of buzz, so to speak, in the past year about using biochar to grow marijuana, but I’d like to address biochar usage with a far more common herbaceous ‘weed’. I am talking about grass, the kind upon which one walks and which needs constant cutting in warm weather! Many people have asked whether biochar can be made from grass, and to be honest in it is recently cut state, it is not generally a great candidate for biochar. For one reason, grass doesn’t have a whole lot of energy value and can be difficult to carbonize without converting it first into pellets. Another issue is that recently cut grass has high moisture content which readers of this blog will know makes charring a challenge.
But as I was driving along miles of NYS Thruway seeing tractors cutting endless stretches of grass, it occurred to me that some of the newer robotic gasifier technologies could be used on these long stretches to not only save money on maintenance, but to mitigate an increasing problem with winter road maintenance: salt. Sodium chloride can cause havoc to surrounding eco-systems, yet substitutes for salt are not without consequence either.
Enter the biochar solution. Self-fueled mowers may sound like future tech, but they are already prototyped and being put to excellent use spinning hay into pellets and using a portion of the pellets to fuel the mowers via gasification technology. Iron Goat Tech has a very interesting version of this type of technology as does EcoMower. Right now the unused pellets are marketed mostly for feed or fuel. But as with biomass technology which is being tweaked to produce biochar instead of ash, these machines can be tweaked to produce biochar instead of pellets. If the char can be safely quenched and left along the mowing path, then it will be able to help prevent salt from leaching into local water bodies, all the while reducing GHG emissions by eliminating the use of fossil fuels as well as sequestering carbon in the soil.
For cities and states looking for a triple win on reducing costs, reducing GHG emissions and ameliorating harm from salting sidewalks or highways, this type of technology looks like it can do it all! No reason to stop at highways either, golf courses, parks, college campuses even residential homeowners could benefit from this exciting new technology!