Hemp Processing Takes Steps to Become Rich Cellulosic Ethanol Source

 

According to a report this week by The Leaf (San Francisco, Calif., USA), 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 in some studies to be no better for the environment than burning fossil fuels, due to overall expenditure of energy in growth, production, and supply, 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, from the University of Wisconsin, has now found a way to efficiently convert the cellulose from the non-usable parts of plants like Hemp. 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 focused on 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 many tree species and grows much faster than most North American trees, it is a potentially better candidate for certain types of specialty paper and/or paper production facilities that do not process lignin, a chemical much more abundant in trees (providing their tall growth and bark's resistance to rot to name a few benefits). However, the sustainable economy, including scientists and investors behind it have found, especially in recent years, additional and potentially valuable uses for lignin as an organic renewable substitute to numerous synthetic materials. For many years it was and has been rumored that the timber and paper industry is opposed to hemp production based on competition. In the economy of our future, one focused on sustainability, it seems they will and must co-exist; hemp to produce supplemental biomass for energy as to not cause wood price fluctuations for the wood product industries, and tree farming to assure a source of paper, including globally growing use of paper packaging, and lignin derived organic building materials capable of making strong moulds such as in automobile chassis / vehicle bodies.  

 

Hemp’s higher cellulose content makes it better than wood for building the homes of the future, which cannot sustainably be made to house billions from wood alone without causing prices of wood to skyrocket. Hempcrete has been around in various countries internationally since the 1960s, but is it quite new to the U.S. 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 be used to make certain types of paper, complimenting wood cultivation and farming instead of supplanting it. As mentioned, it can also produce an abundant natural oil superior to many plants of its type. In the interest of sustainability, the report claims it can also replace everything we currently make out of oil including plastics.

 

Zeoform, cited as an example, is a new type of plastic that uses hemp-derived cellulose mixed with other recycled fibers and water to form a 100% recycled material identical to reformed plastic that now contains cellulose. The density can be changed to make Zeoform suitable for all sorts of industries, everything from aviation and automotive, to musical instruments, and even 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 such as hemp. But now, cellulose or bio-oil based fuels, available from switchgrass and woodwaste for years, possibly with a new infrastructure for the vibrant, fast growth of hemp more specifically able to supplement the needed raw material requirements for a future of clean biofuels to truly stop the expected devastating affects of unchecked CO2 emissions. Fuels made from plants and trees may sequester, or at least balance CO2 emissions, rather than create their atmospheric buildup.

 

A growing consensus of scientists and researchers agree with the idea that biomass is carbon neutral; from top academic professors studying climate, advocates of changing laws related to hemp research and attitudes of investment related to what has become a progressively dated negative association to recreational marijuana (closely related to hemp), to those allied with a variety of closed-loop / grid energy producers such as paper, tissue, and packaging companies tapping into the unused power of a P&P mill's wood raw material leftovers for biofuel in their own plants (a fight supported by the AF&PA as energy experts point out these realities to the EPA in an effort to be recognized as contributing towards a sustainable energy plan) how cellulosic or plant based fuels naturally re-absorb the carbon with each generation planted after the harvest of their parent generations releases it when used for power combustion.