Energy crops are crops that are used mainly for energy production. Large studies have been made in this sector in last 20 years and there is increasing demand for these crops. The main reason for usage of this crops is climate change and high emissions of CO2. Emissions of every biomass, including energy crops, are
Energy crops are crops that are used mainly for energy production. Large studies have been made in this sector in last 20 years and there is increasing demand for these crops. The main reason for usage of this crops is climate change and high emissions of CO2. Emissions of every biomass, including energy crops, are in life cycle zero. These crops are used to change coal and other fossil fuels as primary fuel in production of heat and electricity. You can read below main characteristics of some energy crops and which ones are used in Bosnia and Herzegovina.
According to the EU directive and the Council of Europe No.Â 2003/30/EC from 2003, according to the Article 2 biomass is defined as â€œtheÂ biodegradable parts of products, waste and residues from agriculture, forestÂ waste and related industries as well as the biodegradable parts of industrialÂ and municipal wasteâ€. Thus, biomass consist of products of plant and animalÂ origin and there is also included forest and timber industry residues, residuesÂ in agricultural production, food industry residues, waste etc. AgriculturalÂ biomass that can be used for energy production is different and can be dividedÂ into following groups:
1.Â Arable farming, where we include residues afterÂ the harvest of crops and energy crops
2.Â Livestock, where we include solid manure andÂ slurry
3.Â Perennial crops (orchards, vineyards, oliveÂ groves) where we include branches and wood residues after regular maintenance
4.Â Primary production in agriculture (residues fromÂ wine production, residues from fruit processing, sugar production, wheatÂ procession, oils production and other)
The story begins with the crop Miscantus x giganteusÂ (elephant grass) that is now used worldwide. This perennial crop belongs to theÂ family of grasses and it grows in Southeast Asia, China, Japan and some typesÂ of this crop are growing in Africa. This energy crop achieves excellent yieldÂ and it advantages are: simple cultivation and harvest, perennial plant,Â resistant to diseases and pests and it has very good dry matter yield andÂ calorific value. Once it is planted, it renews every year from the rhizomesÂ that stayed in the ground. The crop is planted in spring and on 1 ha (10,000 m2)Â is planted 10,000 rhizomes. This crop can reproduce itself and stays on oneÂ place for 20-25 years. Some experiments have showed that this crop thieves onÂ low quality soils e.g. tailings, repaired dumps, so they can engage onÂ non-agricultural land which is very important aspect due to the fact that weÂ need agricultural land for food production.
At the first year the yield is lowÂ because crop is still developing, in the second year yield is 6-10 t/ha andÂ after third year and later it reaches its maximum yield of 20-25 t/ha.Â According to professional literature Miscantus has calorific value of 17 MJ/kgÂ and ash content 3.7%. The energy value of 20 tons of Miscantus is equivalent toÂ the energy value of 8 tons of coal.
The next energy crop that is mentioned here is SalixÂ (willow). These crops were originally grown in subtropical area, but later theyÂ spread out to temperate zone and Arctic regions. Today willows are commonlyÂ grown in north temperate regions (Europe, Asia and North America). Fast growingÂ willows require soil which is rich with nutrients and organic matter. TheseÂ crops also require light and water during growth. Lack of water in growingÂ season can affect their height and reduce yield.
In this review we will mention Brassica sp. (oilseed rape).Â These crops are annual plants that can be spring and winter types. Winter formsÂ are grown in moderate climate zones, while spring forms in northern and coldÂ regions. The average yield is 2.5 t/ha. In addition to soy, sunflower and palmÂ it is most important oil crop in the world. It is used in soap, paint,Â textiles, plastic, cosmetic and pharmaceutical production, and in recent yearsÂ in biodiesel production. Biodiesel is environmentally friendly fuel and theseÂ crops are used for its production.
Table 1. CharacteristicsÂ of energy crops
dry matter (t/ha)
energy per ha GJ/ha
|Straw||2 â€“ 4||17||35 â€“ 70||14,5||5|
|Miscantus||8 â€“ 32||17,5||140 â€“ 560||15||3,7|
|Hemp||10 â€“ 18||16,8||170 â€“ 300||n/a||n/a|
|Willow||8 â€“ 15||18,5||280 â€“ 315||53||2,0|
|Poplar||9 â€“ 16||18,7||170 â€“ 300||49||1,5|
|Chervil||15 â€“ 35||16,3||245 â€“ 570||50||5|
|6 â€“ 12||16,3||100 â€“ 130||13||4|
|9 â€“ 18||17||–||15||6|
|Acacia||5 â€“ 10||19,5||100 â€“ 200||35||n/a|
|Wood||3 â€“ 5||18,7||74,8||50||1 â€“ 1,5|
In table 1 we can see main characteristics of energy crops.Â Calorific value of all these crops is going from 16 to 20 MJ/kg. MoistureÂ content is low except for willow, poplar and straw.
In Bosnia and Herzegovina in recent years some steps haveÂ been made when it comes to production of biodiesel. We still cannot beÂ satisfied with the use of Brassica sp. Because our biodiesel is made from usedÂ vegetable oils and fats which are recycled in Srbac, Tuzla. To evaluate theÂ possibility of Miscantus to grow in Bosnia and Herzegovina there have been setÂ couple of experimental fields in country. It is important that we started withÂ some work in this field because we have big potential for biomass and we haveÂ to exploit it.