Biomass最新文献

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.

Evaluation of single cell proteins produced by Chrysonilia sitophila (TFB-27441 strain) with tannin, phlobaphene, bark and lignocellulosic material from Pinus radiata D. Don was made. The amino acids content and its quality were measured by their ratios of individual amino acids to total essential amino acids (A/E ratio) and total essential amino acids to total amino acids (E/T ratio). The values obtained were similar to those of egg and casein proteins. The same trends in the chemical scores were observed. The results of this study indicate that amino acids profiles obtained using bark components as substrates underwent some modification, but in general the obtained proteins could be considered as of excellent quality.

Experimental oil yields obtained from the operation of an entrained-flow pyrolysis reactor using oak as the feed are presented. In addition, a model of the reactor based on the numerical solution of simultaneous differential equations is discussed. Model predictions for oil yields are given and compared with experimental results. Although the maximum oil yield for all experimental runs reported is 51%, the model indicates that oil yields as high as 60% are possible.

It has been recognized that the chemical and physical properties of biomass feedstocks can play an important role in the efficiency of most energy conversion processes. These properties include the ratio of bark to wood, moisture content, specific gravity, calorific or heating value, and the relative content of extractives, α-cellulose, hemicellulose, and lignin.

A review of the literature dealing with the quality of poplar and willow biomass feedstock for energy conversion revealed that considerable variation existed in many of these traits. This variation may make it possible to improve the quality of feedstock through breeding and selection.

Little information exists with respect to heritability (both in the broad sense and narrow sense), the genetic correlation between characters, and the presence of genotype-environment interaction. A better understanding of these parameters is essential if the apparent variability is to be used to improve biomass quality.

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 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.

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.

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.

Performance of a downdraft, biomass gasifier-engine system is reported. Two types of diesel (direct injected and indirect injected) engines used in agricultural applications have been operated with the same gasifier system in the producer gas-cum-diesel, dual-fuel mode. The biomass used in these investigations is Subabool (Leucaena leucocephala). The systems have been evaluated with reference to their thermal, power and emission performance levels. Percentage diesel replacement at different loads has been evaluated as a parameter of interest. It was observed that the various performance facets of dual-fuel operation are considerably influenced by the engine design and operating parameters such as the design of the cooling-cleaning system, especially its volume, which is an important parameter determining the level of diesel replacement as well as the power capacity under dual-fuel mode. The low speed engine was found to be more sensitive to the volume of cooling-cleaning system. It was possible to improve diesel replacement from 68 to 80% at 80% of rated load and maximum power capacity from 3·7 kW to 4·5 kW by changing the volume of the gas cooling-cleaning system. Results of these investigations clearly suggest need for application-specific tuning of the gasifier and the engine units by optimisation of the design of gas processing sub-system for achieving best system performance. It has been established that dual-fuel operation results in substantial increase in engine exhaust CO content, more so at part loads. Reduction in smoke levels under dual-fuel operation is an important advantage irrespective of the engine design and operating particulars.