About Miscanthus

Why Miscanthus for Bio Fuel?

Miscanthus is a genus of perennial grasses. It was extensively researched in Europe and the United States to produce an ideal energy crop for combustion to generate heat and electricity.

Miscanthus has become known to be a viable crop that is both economically profitable and environmentally friendly. The fast-growing Miscanthus x Giganteus is a specialty crop of BioGreens. This is a sterile hybrid (so the crop cannot become invasive), formed by natural hybridization. Stems emerge from an underground rhizome complex annually in March reaching maximum height (3m) towards the end of August. Miscanthus yields more biomass than corn is that it produces green leaves about six weeks earlier in the growing season.

Cooler temperatures in autumn trigger biological aging and change of location of reserves down below ground. The crop is left in the field over winter. During this phase leaf material falls to the ground recycling nutrients and providing mulch that suppresses weed growth in the spring.

At this stage the crop is composed of tall canes that look like bamboo in appearance. By early spring the plant/cane is ready for harvest. As the crop is perennial, once a field is established it is cut back in year one, then harvested annually thereafter for at least 10 years and possibly up to 20 years.

The end product each year is a dry biomass similar in appearance to bamboo canes. This material can easily be processed into a range of forms from conventional bales (such as used for cereal straw) through to compacted forms for different energy end users and uses. The crop is currently harvested and processed using existing farm machinery, but new dedicated equipment is in the pipeline.

Miscanthus also is a very efficient fuel, because the energy ratio of input to output is less than 0.2. In contrast, the ratios exceed 0.8 for ethanol and bio-diesel from canola, which are other plant-derived energy sources. Miscanthus to coal ratio is 12 tons coal to 20 tons Miscanthus.

The main feature distinguishing giant Miscanthus from other biomass crops is its high lignocelluloses yields. In the United States, giant Miscanthus can yield more annual biomass than any other major biomass crop save Saccharin spp. (sugarcane, energy-cane) and has a much broader growing range.

Non Energy Uses

Miscanthus makes an excellent low input game cover crop and once established will produce shoots annually for over 10 years. Miscanthus is used successfully as a high quality bedding product for the equine trade and other markets such as cattle and chicken. Miscanthus can be used for a number of industrial end markets from paper productions through to use in sustainable composite (paper and pulp) materials.

There are a number of advantages to using Miscanthus as a bedding product for animals:

Dust extracted
Low Odour
High absorbency
Long lasting
Economical
Easily disposed of
100% Miscanthus grass

Farmers: The Economics of Miscanthus

It has an estimated productive lifetime of at least 20 - 25 years, and both the stems and leaves of the crop can be harvested annually. Miscanthus is a promising non-food crop, yielding high quality lignocelluloses material for energy, bio fuel/ethanol and fibre production. It is characterised by relatively high yields, low moisture content at harvest, high water and nitrogen use efficiencies and an apparently low susceptibility to pests and diseases.

More Benefits

Miscanthus and other similar energy crop feedstock's can be utilized to produce heat, electricity, liquid fuels (bio-ethanol), industrial materials (bio-composites) & agricultural markets (animal bedding). Miscanthus can be processed into a range of fuel formats. There are many companies that are beginning to use Miscanthus and it derivatives for its commercial, economic and environmental benefits.

The crop, once established needs no pesticide or fertiliser treatments, and offers biodiversity and additional carbon sequestration benefits. Miscanthus is one of the most efficient and environmentally friendly means of producing sustainable biomass for renewable energy markets.
The crop produces biomass 3 times more efficiently than conventional agricultural crops such as wheat or maize.
One of its uses is for the remediation of soils against nematodes, particularly potato soils. Miscanthus is said to be resistant to nematodes. It was tested to see if it would remediate soils contaminated with cadmium, the cadmium killed the rhizomes.
Once established very little or no irrigation is required, minimal amounts of nitrogen fertiliser (50 kg of fertiliser per ha per year is needed), and can be grown on marginal land.
The crop will yield annually for up to 25 years without replanting and is non-evasive.
Miscanthus can be used in co-generation with coal fired power stations to generate electricity and as ethanol.

Environmental Profile of Miscanthus

Miscanthus is more environmentally efficient at producing biomass than annual crops such as cereals. It can produce biomass approximately 3 times more energy efficiently than a crop such as Wheat. This is achieved because Miscanthus does not need high inputs of fertilizer application associated with arable crops and the crop is perennial.

There is therefore only energy expenditure at the start of the 10 year production cycle (to cultivate and spray the land) once, unlike arable crops which require annual energy expenditure to prepare land for planting. In addition, because Miscanthus requires minimal inputs once established, there are no energy requirements during the season to apply pesticides. It also means that the crop can be onward processed into compacted fuels (pellets or cubes) or liquid fuels such as bio ethanol without attracting a negative energy balance, as found with some starch based crops such as Maize (Corn).

Because Miscanthus is a perennial grass, it also accumulates much more carbon in the soil than an annual crop such as corn or soybeans. In the context of global change, that's important because it means that by producing a bio-fuel on that land you're taking carbon out of the atmosphere and putting it into the soil. Miscanthus is one of the most environmentally friendly means of producing biomass for renewable energy. Every tonne of Miscanthus that replaces coal, prevents up to two tones of carbon dioxide being emitted - making an instant impact on carbon emissions. Annual crops that use nitrogen fertilizer (derived from fossil fuels) contribute only a small reduction in CO2 emission.

Comparison of energy balance against other crops

The advantage of supplementing crops such as corn and soybeans with Miscanthus is that its longer growing season allows farmers to harvest the grass long after the corn and soybean harvests have been completed, a time when farmers typically have more time to do harvesting work. Miscanthus produces high yields of biomass with relatively few inputs. As a perennial, fields of Miscanthus can remain productive for many years. Canes of Miscanthus also stand well in the field during winter months. This facilitates storage and makes spring harvest possible for biomass users establishing year-round supply chains.

In terms of the overall environmental profile, the crop is benign when it comes to pests, having a strong energy balance as described, but also having efficient use of water, and positive effects on bio diversity. The sustainability profile of Miscanthus has been evaluated by a number of projects. As an example 100 tonnes of compacted Miscanthus co-fired displaces 55.9 t of coal saving, 148 tonnes of CO2 equivalent emissions. This represents a 94% saving in emissions compared to coal generation of electricity.

Summary

In summary, giant Miscanthus is one of the most promising biomass crops in the world today. It is a cold-tolerant cousin of sugarcane and capable of high biomass yields at cool temperatures. Further, it tolerates marginal lands and some flooding. It is more open to thermo chemical conversion to bio-fuel than biochemical conversion, with good potential for the heat and power as well as the animal bedding industries. Giant Miscanthus is distinguished from other biomass crops, which can be more than double those typical of switch grass. Giant Miscanthus shows an inconsistent response to fertilizer and is generally characterized by low input requirements for production. These low inputs and consistently high yields make giant Miscanthus more profitable that corn/soy in over the long term.

Benefits of Miscanthus (Elephant Grass)

High yielding
Environmentally friendly
Easy to grow
Low maintenance
Annual growing cycle
No pesticides or fertilizers*
Increases wildlife biodiversity
Eligible for cross compliance
Long lifespan
Excellent game cover

*After Established Growing