Biomass最新文献

Six trees of each of 36 red alder (Alnus rubra Bong.) open-pollinated families were harvested from a genetic test plantation in September of the second field season and analyzed for growth and dry weight partitioning. Families from elevations greater than 300 m were significantly shorter than from those below 300 m and tended to be in intermediate or suppressed positions in the plantation canopy. Families from the most southerly drainage system, Santiam, were smaller than those from the more northerly drainages. When low elevation families (those from less than 300 m; 24 of the 36 families met this criterion) were analyzed separately, no statistically significant variation was found among the growth traits. In contrast, significant family variation was found in all of the dry weight partitioning traits and relative crown class. Family heritability (h²) values for low elevation families varied from 0·00 to 0·39 for growth traits and from 0·39 to 0·69 for dry weight partitioning traits. At this age and stage of plantation development, there seemed to be more variation in dry weight partitioning than growth of low elevation red alder families. Family means of the dry partitioning traits varied from as little as 5% to as much as 20% around the population means; hence, it appears that variation in some partitioning traits is large enough to be of practical significance in breeding and tree improvement programs.

Based on 53 tree analyses and 105 sample plots of Eucalyptus globulus, models for volume and biomass at single tree and stand levels were developed. The possible growing sites were divided into four site classes. In seedling stands, the site class I corresponds to yield class 44 m³ ha⁻¹ year⁻¹, in coppice stands to yield class 46 m³ ha⁻¹ year⁻¹. The site class IV corresponds in seedling stand to yield class 9 m³ ha⁻¹ year⁻¹, in coppice stands to yield class 13 m³ ha⁻¹ year⁻¹. The maximum mean annual increment was reached in seedling stands at the age of 18–19 years, in coppice stands at the age of 14 years.

Survival, growth, and insect and disease damage of 54 hybrid poplar clones were compared in a three-year-old genetic selection field trial located in the St Lawrence River Valley, near Massena, New York, USA. Clones were grouped into growth potential classes using cluster analysis and indices of total growth and canker severity. Statistical significance of growth potential classes was tested using discriminant analysis. Seven of the 54 clones examined (DN16, NM6, NE17, D51, DN38, DN55 and NE21) were recommended for additional evaluations in larger scale clone-site trials. The technique presented in this report facilitates hardwood clone performance evaluation for a wide variety of desired products.

The consolidation stage in the compaction of fibrous agricultural materials in an extrusion press has been analysed in order to provide design equations for the optimal choice of die length and estimation of the pulsation domain (region of the die where the material expands and is recompacted repeatedly), for minimisation of die wear. An analysis of the heat flow and transfer processes in the die and the material is also provided. Application of the analyses to the development of a non-frictionally heated biaxial press is discussed. The heated press is designed to be a compromise between conventional extrusion and piston presses, to optimise the qualities of briquettes with power input into material compaction.

Five countries participated in the IEA Activity on chunkwood. The objective was to improve the knowledge of the production and use of chunkwood. Research encompassed production, material characteristics, materials handling, drying and storage, combustion and markets. The results show that the energy consumption is much lower for producing chunkwood than for chips, and the potential capacity is higher. Chunkwood has quicker initial drying, normally less substance losses with seasonal storage and a slightly lower content of fungal spores. The airflow resistance is lower than for chips. The time for complete burnout is about twice as long as for chips. As a whole, the results suggest that a wood fuel with a larger particle size might have several advantages, but also a few disadvantages.

Trials of a common set of seed lots representing 39 parents and five species of Alnus have been started in four countries: Belgium, Canada, the UK, and the U.S. Initial results indicate that cold hardiness is a problem in using A. acuminata but that sufficiently hardy A. rubra sources are available. A. glutinosa had the best growth in the nursery, and A. cordata had the best survival under severe moisture-stress conditions. A summary also is given of a workshop on alder improvement that further demonstrates the potential for developing the genus for biomass energy production.

The thermophilic methanogenic bacterium, Methanobacterium thermoautotrophicum, was grown on H₂CO₂. In continuous culture, high CH₄ productivities were obtained (288 litres litre⁻¹ day⁻¹) with 96% CH₄ in the effluent gas, i.e. the productivity was twice as high as that obtained previously by other authors, with pure or mixed cultures; the biomass was 3·6 g dry wt litre⁻¹.

The interin results of a genetic testing program established within the International Energy Agency (IEA) Forestry Energy Agreement are reported. The ‘Joint Evaluation Activity’ was initiated to evaluate Alnus, Populus and Salix germplasm collected by IEA projects and national programs. The project was designed to compare the growth rates of selected genetic materials under a variety of growing environments, and identify germplasm with potential for biomass cultivation. The project was also designed to examine the limitations of long-distance international transfer of alder, poplar, and willow clones/provenances/species among national biomass programs. Four field tests were established, each containing selected clones and provenances of alder poplar and willow. Three-year growth data are reported here that identify genetic materials with superior growth potential in one or more of the test environments. They also identify the maximum climatic tolerance of several previously untested species/provenances. The results can be used to guide the selection of materials for future exchanges among the national programs participating in the study.

In this paper heating values and ultimate analysis of groundnut shell, coconut shell and palm kernel shell are reported. In addition, the quantity of air required for perfect combustion, volume of products of combustion and the temperature of combustion products have been calculated.

The moisture-free higher calorific values of palm kernel shell, groundnut shell and coconut shell are 25·46, 15·70 and 22·89 MJ/kg respectively.