**9. Conclusion**

290 Sustainable Growth and Applications in Renewable Energy Sources

The high alkali content, which was adsorbed during the lifetime of the plant, causes the low ash melting point of the energy grass. This causes combustion problems because the ash melting occurs in the operating temperature of boiler. The material can melt and sick onto the surface of the structure elements of the boiler, and this will lead to interior depositions and permanent damage. To solve this problem, new boiler and grate types were developed. The part of the combustion chamber where the fuel burns in solid phase cannot reach high enough temperatures for the ash melting. Continuous movement of the fuel also helps to avoid scorification and interior depositions. Boiler technology was developed so that the fuel is moving on a moving grate in the boiler while the volatile component of the fuel is gasified between 150°C and 400°C**.** The charred roughage falls off the grate to the ash pit before the fuel would be able to reach the critical melting temperature (Fig. 17.). The volatile component is burnt in the second part of the boiler (the so-called post-combustor) where the temperature of the combustion chamber is approx. 800-900°C. The problem of ash melting was solved and sufficient burnout of the combustion gas was also ensured by this new technical solution. Based on this operating principle there are many structural solutions and

The boilers, which are suitable for energetic utilization of the energy grass, can be ranked

Due to their structure and size the low power equipments are mainly operated with pellet fuel. These automatic systems are suitable for the combustion of energy grass pellets with appropriate efficiency and low emission. The size of the boiler and the manufacturing cost are greatly increased by the necessary moving grate. These equipments are more robust than the prevalent wood-pellet boilers. Medium power equipments are primarily used in communal and social facilities, which are mainly operated using pellets. They are

Fig. 17. Ash melting diagram of fuels

performances available on the market.

into three different groups based on their performance levels.




A new energy crop (*Elymus elongatus* subsp. *ponticus* cv. Szarvasi-1, tall wheatgrass) has recently been introduced to cultivation in Hungary to provide biomass for solid biofuel energy production. The cultivar was developed in Hungary from a native population of *E. elongatus* subsp. *ponticus* for agronomic and energetic purposes. The main goal of our research was to investigate the performance of Szarvasi-1 energy grass under different growing conditions (e.g. soil types, nutrition supply). We focused on the ecological background, biomass yield, weed composition, morphology, ecophysiology and the genetics of the plant.

The biomass yield of Szarvasi-1 energy grass depends mainly on the presence of macronutrients, soil texture and water availability of fields. Under typical soil nutrient conditions, precipitation has a considerable effect on biomass yield. Average yield of Szarvasi-1 energy grass is as much as 10-15 t DM ha-1 with great spatial and temporal variation depending on weather and habitat conditions. As part of an intensive agricultural management, the use of fertilizers can be a good solution when soil nutrients are inadequate. Nitrogen plays an important role in increasing biomass in any phenophases of Szarvasi-1 in the course of annual growth (Fig. 18.).

Tall Wheatgrass Cultivar Szarvasi–1 (*Elymus elongatus* subsp. *ponticus* cv. Szarvasi–1)

herbaceous energy plant for arid or semi-arid lands in Eastern Europe.

Emily Rauschert for the thorough linguistic corrections of our manuscript.

194, No. 3-4, (September 1995), pp. 189-205, ISSN 0378-2697

Thinopyrum Á. Löve, 8 June 2011, Available from:

(November 1997), pp. 1361-1371, ISSN 0140-7791

New Mexico Botanist, Vol. 17, (January 2001), pp. 1-8.

Szt. István Egyetem ISBN 978-963-9483-77-4 pp. 89-92

impossible according to our results.

**10. Acknowledgement** 

**11. References** 

as a Potential Energy Crop for Semi-Arid Lands of Eastern Europe 293

In order to maintain a standard quality of Szarvasi-1 as an energy crop, it was essential to clarify its genetic characteristics. RAPD-based DNA fingerprinting revealed a low level of genetic variability among samples of the cultivar. In addition, a comparative analysis of three native Hungarian *Elymus elongatus* populations and Szarvasi-1 cultivar confirmed their genetic identity, having found no specific marker characteristic only for the latter. Ecological risk of unwanted gene exchange among close taxonomic relatives may be rather low but not

Moderate phenotypic plasticity, enormous capability to suppress weeds, high potential to produce biomass even among drier climatic conditions and a relatively high energy and moderate ash content suggest that tall wheatgrass cultivar Szarvasi-1 has great potential as a

Our research and publication were financially supported by NKFP 3A/061/2004 and TÁMOP-4.2.2/B-10/1-2010-0029. Special thanks should be given to John Michael Lynch and

Assadi, M. Runemark, H. (1995). Hybridization, genomic constitution and generic

Barkworth, M. (2011). Thinopyrum ponticum (Podp.) Z.W. Liu & R.R.-C. Wang, In:

Bleby, T.M.; Avcote, M.; Kennett-Smith, A.K.; Walker, G.P. & Schachtman, R.P. (1997).

Cox, G.W. (2001). An inventory and analysis of the alien plant flora of New Mexico. The

Díaz, O.; Sun, G. L.; Salomon, B. & Bothmer, R. (2000). Levels and distribution of allozyme

delimitation in Elymus sl (Poaceae, Triticeae). Plant Systematics and Evolution Vol.

http:// herbarium.usu.edu/webmanual/info2.asp?name=Thinopyrum\_ponticum

Seasonal water use characteristics of tall wheatgrass (Agropyron elongatum (Host) Beauv.) in a saline environment. Plant Cell and Environment Vol. 20, No. 11,

and RAPD variation in populations of Elymus fibrosus (Poaceae). Genetic Resource and Crop Evololution, Vol. 47, No. 1, (February 2000), pp. 11-24, ISSN 0925-9864 Guadagnuolo, R.; Bianchi, D. S. & Felber, F. (2001). Specific genetic markers for wheat, spelt,

and four wild relatives: comparison of isozymes, RAPDs, and wheat microsatellites. Genome, Vol. 44, No. 4, (July 2001), pp. 610-621, ISSN 0831-2796 Häfliger, E. Scholz, H. (1980). Grass Weeds. Vol. 2. CIBA-GEIGY Ltd. Basel, Switzerland Heslop-Harrison, Y. Shivanna, K.R. (1977). The Receptive Surface of the Angiosperm

Stigma. Annals of Botany Vol. 41, (November 1977), pp. 1233-1258, ISSN 0305-7364 Janowszky, J. & Janowszky, Zs. (2007). A Szarvasi-1 energiafű fajta – egy új növénye a

mezőgazdaságnak és az iparnak (Szarvasi-1 energy grass – a novel crop for the agriculture and industry) In: Tasi, J. A magyar gyepgazdálkodás 50 éve Gödöllő,

Johnson, R.C. (1991). Salinity resistance, water relations, and salt content of crested and tall wheatgrass accessions. Crop Science Vol. 31, (n.d.), pp. 730-734, ISSN 0011-183X

Fig. 18. Energy grass field in Baranya county (photo: Róbert W. Pál)

Quantitative analyses of the plant material of Szarvasi-1 were conducted to describe the chemical profile of the biofuel. Ash and energy content were determined by combustion experiments in laboratory while the dynamics of firing were studied in different experimental furnaces. We developed best practices for combusting Szarvasi-1 biofuel.

Dry matter content of Szarvasi-1 is highly influenced by the morphological features of the vegetative organs. The occurrence and proportion of mechanical and vascular tissues were investigated in the leaves and culms of Szarvasi-1 in various experimental settings for two years. Having examined the effect of different soil types on the anatomical characteristics of the culm and the leaves, we determined the most favourable habitat types of this energy plant to achieve the highest biomass yields with the greatest dry matter content.

Ecophysiological regulation and the threshold limits of gas exchange parameters (assimilation, transpiration, water use efficiency, stomatal conductance) of Szarvasi-1 were also investigated. For abiotic environmental variables, air humidity and light had the most significant effect on gas exchange parameters. Assimilation curves and some characteristic values (e.g. light compensation and efficiency, assimilation capacity) were different at the beginning of the growing period on all studied soil types. These parameters characteristically declined under water-limited environmental conditions. Water limitation had a slightly positive effect on water use efficiency. Ecophysiological conclusions, drawn from gas exchange analyses, can be utilized for planning biological and agronomical aspects to achieve higher biomass production, in accordance with the abiotic environmental regime.

The typical weed composition and abundance in energy grass fields were compared to other arable crop cultures. Weed-crop competition was also investigated in different soil conditions. The weed composition of energy grass fields is more similar to perennial cultures like alfalfa than to other annual ones (cereals, row crops). Although no herbicide treatment was carried out, percent cover of Szarvasi-1 energy grass increased significantly year by year with decreasing weed cover and species number. By the second year, the average weed cover dropped from the first year's value of 48 % to 17 % and in the third year it did not exceed 4 %. Different soil types had different effect on the temporal variation of weed composition.

In order to maintain a standard quality of Szarvasi-1 as an energy crop, it was essential to clarify its genetic characteristics. RAPD-based DNA fingerprinting revealed a low level of genetic variability among samples of the cultivar. In addition, a comparative analysis of three native Hungarian *Elymus elongatus* populations and Szarvasi-1 cultivar confirmed their genetic identity, having found no specific marker characteristic only for the latter. Ecological risk of unwanted gene exchange among close taxonomic relatives may be rather low but not impossible according to our results.

Moderate phenotypic plasticity, enormous capability to suppress weeds, high potential to produce biomass even among drier climatic conditions and a relatively high energy and moderate ash content suggest that tall wheatgrass cultivar Szarvasi-1 has great potential as a herbaceous energy plant for arid or semi-arid lands in Eastern Europe.
