Source: theleafonline.com
Hemp has been reported to have some of the most diverse uses out of any plant currently known. One new use for hemp is as a raw material for biofuels, namely as cellulosic ethanol, which unlike other methods of making biofuels, uses a plant’s cellulose instead of the oil or sugar it contains to produce a fuel. While corn-based ethanol has been shown to be no better for the environment than burning fossil fuels, cellulosic ethanol is much closer to being carbon-neutral.
Cellulose is what forms the structure of green plants, everything from grass to trees. Professor George Huber, at the University of Wisconsin, has found a way to convert the cellulose from the non-usable parts of plants, such as yard waste, compost scraps, or wood debris into ethanol and other bio-oils. “The goal of the Huber research group is to develop the clean technology that will allow us to economically use our biomass and other sustainable resources for the production of cheap renewable gasoline, diesel fuel, jet fuel, and chemicals.”
Professor Huber’s work is revolutionary because it will allow cities to turn a large portion of their garbage into fuel that can power buses and other city vehicles. Clearly, waste material alone will not be enough to switch our current fossil fuel economy to a grassoline economy, which is where hemp comes in.
Hemp is ideal as a fuel-stock for cellulosic ethanol for several reasons. Hemp has an exceptionally high cellulose content, it grows very quickly allowing for multiple harvests per year, it can be grown in nearly all climates, it is drought resistant, frost resistant, pest resistant, and unlike other fuel-stocks like switchgrass, hemp has edible seeds which can be harvested allowing for two harvests from one crop. While switchgrass may grow quickly like hemp, it’s cellulose content is roughly half that of hemp, which has a higher cellulose content than wood.
Currently, while bio-oils can be produced for under $1 a gallon, they faces several issues in being adopted widely around the country. Bio-oils cannot be used in existing gasoline and diesel fuel engines because they have lower energy densities and a higher oxygen content. Bio-oils are also nearly-insoluble with petroleum fuels, making it impossible to have a flex-fuel vehicle that uses a combination of each. Finally, bio-oils degrade over time and are acidic with a pH of 2.5, limiting options in fuel storage. If sugars are added to bio-oils to ferment them into cellulosic ethanol, there are additional challenges, such as the need for sterile conditions, the lengthy residence time of the chemicals, and the distillation of ethanol from water is very energy intensive. Professor Huber is already working on solutions to these problems, while he does, hemp’s exceptionally high cellulose content coupled with fast growth and low costs to grow make it ideal for more than just bio-fuels.
Since hemp has a higher cellulose content than trees and grows much faster than even the fastest growing trees, it is a much better candidate for paper than current lumber options, such as pine. The world currently produces over 400 million tons of paper every year, imagine if all of that was easily replanted hemp instead of trees which take years to grow to maturity.
Beyond paper, hemp’s higher cellulose content makes it better than wood for building the homes of the future, which cannot sustainably be made from wood alone. Hempcrete has been around in other countries since the 1960s, but is it quite new to America due to the federal ban on industrial hemp production, only recently lifted. Hempcrete is remarkably strong yet also very lightweight, about 1/7th the weight of concrete.
Now, America’s first hemp house has been built in North Carolina, and it may also be the first carbon-neutral house in the country. According to the Limecrete Company, a UK based hempcrete manufacturer, hempcrete is carbon negative because “the carbon trapped in the hemp offsets the carbon not only of the hemp production but also the residual carbon from the lime production after re-absorption of carbon as the lime cures.”
Hemp can replace more than paper, wood, and oil, it can also replace everything we currently make out of oil including plastics. Zeoform is a new type of plastic that uses hemp-derived cellulose mixed with other recycled fibers and water to form a 100% recycled plastic. The density can be changed to make Zeoform suitable for all sorts of industries, everything from aviation and automotive, to musical instruments and McDonalds toys. Zeoform and hempcrete will not stop the steady onslaught of greenhouse gas emissions and climate change on their own, but they mark the beginnings of a trend towards widespread use of more environmentally friendly raw materials, and may also sequester CO2 emissions rather than create them. Thanks to modern science and technologies, like cellulosic ethanol, humanity may be approaching another time when we can declare Hemp for Victory, as we did in World War II.
No comments:
Post a Comment