Biomass Yield and Fuel Properties of Different Poplar SRC Clones

Abstract

The goal of the research was to determine the biomass yield and fuel properties of ten different poplar clones. The research was conducted in an experimental plot established in Forest Administration Osijek, Forest Office Darda, in the spring of 2014. The layout of the plot consisted of three repetitions per clone with 40 plants per repetition in spacing 3x1 m. Based on the DBH distribution, in the early spring of 2018, one sample tree of an average DBH per repetition was selected, thus forming a sample of 30 trees. Average survival rate of the investigated trees after four vegetation periods was 74.54 ±13.85% ranging from 52.08% (Koreana) to 91.67% (SV885 and SV490). Average DBH of the sample trees was 8.2 ±1.9 cm, height 9.3 ±1.8 m and root collar diameter 10.7 ±1.9 cm. Moisture content in fresh state (just after the felling) ranged from 51.6% (Hybride 275) to 55.9% (SV885). Bark content averaged 18.4%, from 15.4% (Baldo) to 21.1% (V 609). Average nominal density of the sampled trees amounted to 383.5 ±35.9 kg/m3. Bark ash content was on average ten times higher (6.44 ±0.65%) than wood ash content (0.64 ±0.07%) resulting in average ash content of 1.7 ±0.1% (taking the bark content into account). The clone SV490 showed the highest biomass yield with 15.8 t/ha/year, while the lowest biomass yield was recorded for the clone Hybride 275 with 2.8 t/ha/year. High inter-clonal productivity variation stresses the importance of selection work to find the most appropriate clones with the highest productivity potential for the given area where the poplar SRC plantations are to be established. Due to high initial moisture content, if direct chipping harvesting systems are preferred, wood chips could be efficiently used in CHP (Combined Heat and Power) plants that operate on the principle of biomass gasification (where a gasifier is coupled to a gas engine to produce electric power and heat). In several CHP gasification plants operating in Croatia, wood chips with high initial moisture content (from traditional poplar plantations) are used as a feedstock that has to be pre-dried using the surplus heat. In this respect SRC poplar wood chips could make an ideal feedstock supplement.

Comprehensive Overview of REDD+ in India: Status, Opportunities and Challenges

“…The variation in biomass production, partitioning and per cent contribution to plant components of clones was reported by many workers (Dinko et al, 2017;Swamy et al, 2006;Saravanan, 2019). Similar observation of the higher branch biomass in the highest biomass accumulated clone was found in the hybrid aspen (Populus tremula × P. tremuloides) clone (Hytonen et al, 2020).…”

“…Total above ground dry biomass (kg) was 0.002604(G) ^ 2.7826), where 'G' is the girth (trunk) at 150 cm, which was validated (Ambily et al, 2012) for the rubber clones in India. Similar method of the estimation of biomass using allometric equation was reported for the coniferous and broadleaved mixed forest in north-eastern China (He et al, 2018) and among Poplar SRC clones (Dinko et al, 2017). The allometric equation for biomass estimation was also reported in Olea europaea, L. Subsp.…”

Comparison of the Initial Growth of Different Poplar Clones on Four Sites in Western Slovakia—Preliminary Results

“…'Matrix 49' was also planted on R05, under dry conditions, and their differences between the growth were clearly visible (Table 6). Vusić et al [55] described similarly weak growth in the case of 'Hybride 275', 'Matrix 21', and 'Max 4' in Croatia. 'Bakan' and 'Skado' have shown higher growth under the oceanic climate in Belgium than DN hybrids [56].…”

Variability of Normative Properties of Wood Chips and Implications to Quality Control

“…Energy wood with bark also showed favorable ash content results, considerably lower than average values for similar raw material reported in the previous research [50], which could indicate a proper raw material handling in the procurement chain in terms of selecting adequate harvesting equipment and proper storage. Previous research found extreme differences between wood and bark ash contents, the latter being up to ten times greater for instance in the case of SRC poplar [40]. On the roundwood level, ash content is a result of natural levels of bark and wood ash but also favorable wood to bark ratio.…”

“…Ash content of wood chips is directly affected by the natural organic to inorganic matter ratio of the raw material. Apart from the naturally occurring negative effect of the present tree parts that contain significant amounts of leaves/needles or the unfavorable bark-to-wood ratio, common, for e.g., in the raw material originating from the SRC [39,40], the final product ash content can be negatively affected by inorganic matter (e.g., dirt, sand) contamination during the harvesting process [41] or by organic matter deterioration during storage [17]. Positive effects can be achieved by proper raw material manipulation; for instance, by seasoning of forest residues to lower the amount of foliage [20] or by debarking of the raw material prior to grinding, drying, and palletizing [42], which is a common practice of the quality upgrade in pellet production process when energy roundwood is used as raw material [43].…”