14 May 2015

9 Ways Hemp Can Help

1) We can stop cutting down forests for paper products and use hemp to make paper

There are four characteristics of hemp which make it particularly appealing for making paper:

Hemp fibres are long (makes for stronger paper which can be recycled more times than wood paper); 
Hemp contains high levels of cellulose (57-77%) and more cellulose makes for more pulp; 
Hemp has low (3%) lignin content (this is what makes wood-pulp paper turn yellow over time); 
One acre of hemp can produce as much usable fibre as four acres of trees. Hemp can be harvested every 100 days. Trees take decades to harvest.

The best part about hemp-based paper is that its production is environmentally friendly. Wood paper? Not so much … 

Due to its chemical and physical composition, hemp can produce high pulp yields and can be pulped without use of the Kraft process (chemical pulping of wood and long-fibre speciality papers) which uses sulphur compounds that are environmentally toxic. Also, as with other non-wood pulp, hemp can be bleached with peroxide and through other processes that do not involve chlorine.

2) We can build stronger homes with it, use less lumber and create carbon neutral structures

Hemp has some fascinating qualities for a natural fibre. One of the building products made from hemp is called Hempcrete. It’s a good acoustic dampener, it breathes (doesn’t trap vapours and humidity) and is a good insulator. And while it doesn’t have great potential as a structural (load-bearing) material on it’s own, it does have exciting possibilities as insulation that strengthens the existing structure. Hempcrete infill can increase, up to 4 times, the strength of a timber wall by preventing weak axis buckling by acting as continuous lateral elastic support.

With Hempcrete, construction costs are reduced by: shallower foundations; 30-40% less lumber, labour in framing; lower transport costs of materials to site; lower finish costs; discounted insurance costs; reduced mechanical (HVAC) requirements; NO termite fumigation needed after build

Another product, called Cannabric, can be used as a load bearing material for buildings of multiple floors. It provides much of the same acoustic, insulating and breathing benefits of Hempcrete, but it can also replace nearly all of the lumber or steel support used in typical construction.

The mineral components of the Cannabric are responsible for its mechanical hardness, its density and its excellent thermal inertia. The result is a brick of low thermal conductivity (0,1875 W/m·K) and high specific thermal capacity (1291 kJ/m3·K); it possesses thermo-physical characteristics to protect against both cold and hot climates. All this with one-layer walls of small thickness, without additional thermal insulation.

Another fascinating benefit of almost every hemp-based building material is that they are carbon negative. No, not carbon neutral, but carbon negative. In other words, hemp absorbs so much carbon from the atmosphere while it is growing that even the gas-powered machines used to harvest it, to manufacture it and to transport it do not equal as much carbon as it has already absorbed. Cannabric has a GWP (Global Warming Potential) of -0.624 kg CO2 eq/kg, that means negative. It is a material that retains CO2. In its manufacturing processes (materials, transport, used energy) it does not contribute to global warming.

3) We can fuel our cars with hemp 'gasoline' (petrol) and bio-diesel and stop burning fossil fuels

We’ve all heard of bio-diesel, and any vegetable oil can be made into bio-diesel. What’s really a game-changer is hemp can be used to make 'green gasoline', almost identical to the stuff we currently put into our combustion engine vehicles, but derived completely from cellulose.

In 2008, US researchers made a breakthrough in the development of green gasoline, a liquid identical to standard gasoline, created from sustainable biomass sources. Chemical Engineer George Huber of the University of Massachusetts-Amherst (UMass) and his graduate students announced the first direct conversion of plant cellulose into gasoline components. "Green gasoline is an attractive alternative to bio-ethanol since it can be used in existing engines and does not incur the 30% gas mileage penalty of ethanol-based flex fuel. In theory it requires much less energy to make than ethanol, giving it a smaller carbon footprint and making it cheaper to produce. Making it from cellulose sources such as switchgrass or poplar trees grown as energy crops, or forest or agricultural residues such as wood chips or corn stover, solves the life-cycle greenhouse gas problem that has surfaced with corn ethanol and soy bio-diesel", said John Regalbuto at the US National Science Foundation (NSF) who supported this research.

"Huber's ... process for the direct conversion of cellulose to gasoline aromatics is at the leading edge of the new ‘Green Gasoline' alternate energy paradigm that NSF, along with other federal agencies, is helping to promote. Not only is the method a compact way to treat a great deal of biomass in a short time, the process, in principle, does not require any external energy. In fact, from the extra heat that will be released, you can generate electricity in addition to the bio-fuel. There will not be just a small carbon footprint for the process; by recovering heat and generating electricity, there won't be any footprint."

And it turns out, hemp is the best plant in the world to produce biomass for cellulosic gasoline. According to the paper Energy Farming in America, "Hemp is the world’s most versatile plant. It can yield 10 tons per acre in four months. Hemp contains 80% cellulose; wood produces 60% cellulose. Hemp is drought resistant making it an ideal crop in the dry western regions of the country".

Once this technology has evolved sufficiently to be cost effective on a large scale, it will confirm that hemp, Cannabis sativa, is a superior cultivar for bio-fuel production. Hemp exhibits far superior ethanol yields per unit biomass compared to corn or switchgrass which are the two most supported cultivars for bio-fuel by the US government.

Industrial hemp on a large scale is not a crop considered viable in Australia by the Australian government. 

If the production of cellulosic gasoline (supplied by hemp) ramps up to the point that most vehicles can be fuelled with it, simply using cellulosic gasoline will reduce greenhouse gas emissions (GHG) by 85% compared to reformulated petrol or ethanol.

4) We can start to solve world hunger with the complete proteins and amino acids of hemp seeds

Hemp is cheap to grow, and it grows almost everywhere. So we could grow a whole lot of it for very little. And while we're using all that cellulose from hemp’s biomass to make gasoline (petrol) and clothes and better materials for our homes, we could be using the seeds for food.

Technically a nut, hemp seed typically contains over 30% oil and about 25% protein, with considerable amounts of dietary fibre, vitamins and minerals. Hemp seed oil is over 80% polyunsaturated fatty acids (PUFAs) and an exceptionally rich source of the two essential fatty acids (EFAs) linolenic acid (18:2 omega-6) and alpha-linolenic acid (18:3 omega-3). The omega-6 to omega-3 ratio (n6/n3) in hemp seed oil is normally between 2:1 and 3:1, which is considered to be optimal for human health. In addition, the biological metabolites of the two EFAs, gamma-linolenic acid (18:3 omega-6; ‘GLA’) and stearidonic acid (18:4 omega-3; ‘SDA’), are also present in hemp seed oil. The two main proteins in hemp seed are edestin and albumin. Both of these high-quality storage proteins are easily digested and contain nutritionally significant amounts of all essential amino acids. In addition, hemp seed has exceptionally high levels of the amino acid arginine. Hemp seed has been used to treat various disorders for thousands of years in traditional oriental medicine. Recent clinical trials have identified hemp seed oil as a functional food and animal feeding studies demonstrate the long-standing utility of hemp seed as an important food resource.

What could be accomplished if hemp were being grown in large quantities all over the world for fuel, for clothing, for paper and so on? How many could we feed with all those hemp seeds?

5) We can make clothing and fabrics with a fraction of the environmental impact and water consumption of cotton

For millennia, humankind has made clothing from hemp’s long, strong fibres. Turning to hemp as a source of textile fabric would actually be a re-turning to hemp. The environmental impact of increased hemp production over cotton would be tremendously positive. Cotton requires more water, more fertilisers, more herbicides and more pesticides to grow.

Hemp represents the lowest ecological footprint of the three textiles. The footprint of hemp does not vary significantly in the different case studies, starting at 1.46 g/ha and reaching 2.01 g/ha. As with cotton, crop cultivation represents the greatest proportion of the ecological footprint in the hemp case studies. Again, this can be attributed to the land area required to grow the crop. However, unlike cotton, hemp productivity levels are much greater with yields of up to 3 tonnes of dry fibre per hectare compared to 1.35 tonnes of cotton lint per hectare.

When it comes to water needs, cotton loses by a landslide to hemp. It takes just over 4,474 litres (1,182 gallons) of water to produce 0.45 kg (1 lb) of usable cotton. It takes over 961 litres (254 gallons) of water to produce 0.45 kg (1 lb) of usable hemp fibre.

6) We can reverse / negate the effects of carbon emissions on global warming

Through carbon bio-sequestration, a process of capturing carbon emissions from the atmosphere through plants, we can trap or, 'sequester', carbon from the air into plants. Once the plants are harvested we can then create a substance called biochar, not through burning the plants, but slow-smouldering them to create a form of charcoal, which we then mix with nutrients and bury back into the soil.

The ancient tribes of the Amazon had this process figured out a long time ago. There’s a particular type of soil made from this active human interaction called 'terra preta' and it’s spectacular stuff. Compared with the surrounding soil, terra preta can contain three times as much phosphorus and nitrogen. 

Leaving aside the subtleties of how char particles improve fertility, the sheer amount of carbon they can stash away is phenomenal. In 1992, Sombroek published his first work on the potential of terra preta as a tool for carbon sequestration. According to Glaser’s research, a hectare of metre-deep terra preta can contain 250 tonnes of carbon, as opposed to 100 tonnes in unimproved soils from similar parent material. The extra carbon is not just in the char — it’s also in the organic carbon and enhanced bacterial biomass that the char sustains.

But what does hemp have to do with this? Hemp is one of the highest yielding biomass crops on the planet, and it takes far less water and fertiliser to grow than other high-yielding biomass plants. Seen as a carbon sequester, hemp might give as much as 13 tonnes of charcoal per hectare annually, which would outdo salix plantations (a popular biomass crop) by about three times.

7) We can stop using as much toxic herbicide and pesticide and restore our soils

Hemp has been on earth for a long, long time, and for millennia, our ancestral farmers grew it everywhere and knew how to take full advantage of it. One of its main benefits was in crop rotation. Until hemp became illegal to cultivate in the early twentieth century, farmers regularly planted hemp as a part of their crop rotation. Why? Because it naturally restored the fields for use by other crops through numerous mechanisms:
restores vital nutrients into the soil.removes chemicals from the soil (phyto-remediation)
naturally killed off invasive plant species (weeds) without the use of chemical herbicides.
relatively pest-resistant, so entire hemp crops didn’t need to use pesticides, allowing the field’s soil to be chemical free for the next crop’s planting.

Hemp absorbs CO2 and converts carbon dioxide into oxygen and improves the soil in which it is grown. Sometimes used as a 'mop crop' and planted on some farms to restore the soil’s nutrients during agricultural crop rotation, hemp has the phyto-remediation potential to remove toxins in the soil. Hemp offers real environmental advantages, particularly with regard to the limited need for herbicides and pesticides. Hemp is pre-adapted to organic agriculture and accordingly, to the growing market for products associated with environmentally-friendly sustainable production.

8) We can reclaim land destroyed by pollution, radiation, and toxic wastes

Hemp is a member of an elite class of hearty plants that can naturally extract and filter toxins and pollutants from some of the worst disasters in the world, even radioactive soils. This is a process of soil recovery known as phyto-remediation. Why use hemp as a phyto-remediator? 

high biomass which is unaffected by pollutants
root can grow up to 2.5 metres (8 feet) below ground
low growing cost
quick growing season
full maturation in 180 days
good accumulator from air and soil

Contaminated products can be used for industrial purposes: Bio-diesel fuels, industrial lubricants and varnishes, insulation, construction materials, paper, clothing, food and plasticised or composited materials for a variety of uses.

A number of studies have identified industrial hemp as a top candidate in bio-remediation, especially phyto-extraction of heavy metals from industrially contaminated soils. Hemp has been used to process grey-water in Australia, extensively tested in Europe for the removal of heavy metals from soil, including cadmium, lead, copper, zinc, and nickel often associated with mining, used for the clean-up of polycyclic aromatic hydrocarbons at a site in Hawaii and cultivated on radionuclide-contaminated soils at the Chernobyl nuclear reactor site.

9) We can power coal-powered plants with much lower sulphur pollution (or even none)

Coal. A dirty word for many. A cheap source of electrical power for most. And one of the most devastating sources of pollution in the modern world. But we can cut emissions from coal plants by simply adding hemp biomass to the coal being burned. By blending coal with biomass materials such as hemp, sulphur emissions from power generation can be reduced (by 40%) and less valuable coal that is high in sulphur can remain competitive.

Even more exciting is the prospect of bio-coal, a complete alternative to replace traditional coal with almost no sulphur emissions at all . Currently, most bio-coal is made from wood, but as we know hemp has a higher cellulose content (57-77%) than wood (38-49%) it stands to reason that as we begin to grow hemp more efficiently and in more abundance, that we could eventually derive more cost productive and efficient bio-coal from hemp.

So, all this information is great, but where are all these amazing hemp products? Where’s the hemp?

Officially, hemp is still illegal to grow in many states across the US and in Australia the fledgling hemp industry has been trying to join the rest of the developed world and produce oil and food for human consumption. A prohibition on growing industrial hemp in Australia was lifted in the late 1990's, but Australian farmers are restricted to growing fibre and construction materials and politics has prevented them from gaining access to booming hemp food markets (hemp isn't legal for human consumption in Australia and New Zealand). Industrial hemp is grown by Australia's biggest producer on farms and facilities in New South Wales, Queensland and Tasmania, producing about 2,000 tonnes of raw material a year.
The US is finally getting 'turned on' by all the possibilities of hemp. With all that this amazing plant has to offer, and all the ways that it can change our world for the better, we need to support hemp growers, producers (and their products) and further research.

Illegally green: Environmental Costs of Hemp Prohibition
Structural Benefits of Hempcrete Infill in Timber Stud Walls

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