WOOD. Research papers. Reports. Announcements - No. 174 2005

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ISSN 1644-3985

 

Contents


RESEARCH PAPERS
Mariusz STOLARSKI, Hanna WROBLEWSKA, Wojciech CICHY, Stefan SZCZUKOWSKI, Jozef TWORKOWSKI: 
Chemical composition and carorific value of basket willow  wood obtained from arable lands
(Polish language version)
 5
Marek JUSZCZAK: 
Laboratory research on the thermal utilization of pine-tree wooden waste in heating boilers
(English language version) 
17 
Mariusz JOZWIAK, Stanislaw PROSZYK, Witold JABLONSKI:
Influence of urea on the course of the gelation process and the degree of hardening of the adhesive mixture from melamine-urea-formaldehyde resins
(Polish language version) 
31 
Vadim GRIGORIEVICH ULASOVEC: 
The volume yield of edged saw-timber acquired from unedged using different methods of log sawing 
(English language version)
41 

REPORTS 
Wladyslaw STRYKOWSKI, Anna LEWANDOWSKA, Andrzej NOSKOWIAK, Zofia WAWRZYNKIEWICZ: 
Environmental life cycle assessment (LCA) in the wood industry – possibilities and challenges 
(Polish language version) 
55 
Sergiusz SUBOCZ: 
Characteristics of forests resources of the Republic of Belarus
(Polish language version)  
67 

ANNOUNCEMENTS 
Przemyslaw GACA: 
The 10th International “Indoor air 2005” Conference
(Polish language version)  
75

 

Summaries

 

RESEARCH PAPERS

Mariusz STOLARSKI, Hanna WROBLEWSKA, Wojciech CICHY, Stefan SZCZUKOWSKI, Jozef TWORKOWSKI: 
Chemical composition and carorific value of basket willow  wood obtained from arable lands
(Polish language version)

The object of the work was to assess the usability of  willow coppice (Salix viminalis) wood from a field culture on a brown soil of IIIa class of a wheat complex of good quality, for energy and industrial purposes on the basis of the chosen chemical-physical properties of this wood. Analytic samples were taken from wood of one-, two- and four-year-old shoots in bark and from debarked one-year old shoots and the bark obtained from them. Basic chemical composition of willow wood (content of cellulose, lignin, pentosanes and substances soluble in water, in 1-percent NaOH and in ethanol-benzene mixture), elementary composition (N, C, H), macro elements content (N, P, K, Mg, Ca, Na, Cl and S), ash, heat of combustion and calorific value were determined. No significant differences in the chemical composition and energy properties of Salix viminalis wood depending on its age were observed in the tested range of 1, 2 and 4 years (cellulose - from 41,54 to 44,86%; lignin - from 19,72 to 23,88%; substances soluble in 1-percent NaOH - from 21,14 to 23,28%; ash - from 0,78 to 2,78%; calorific value - from 17 685 to 18 077 kJ . kg-1). Whereas the bark obtained from the one-year-old willow shoots differed significantly from the other samples of the tested wood (cellulose - 35,05%; lignin - 37,05%; 1% NaOH extract - 51,61%; ash - 6,89%; calorific value - 17 008 kJ . kg-1).
On the basis of the gained results it can be stated that non-debarked basket willow (Salixviminalis) wood cultivated on arable lands is suitable to be used for energy and industrial purposes (cellulose, panels).

Marek JUSZCZAK: 
Laboratory research on the thermal utilization of pine-tree wooden waste in heating boilers
(English language version)
 

The thermal utilization was done in the heat station belonging to the Poznan University of Technology, Division of Heating, Air Conditioning and Air Protection. Dry pine pieces (about 20-30 cm long and 5-10 cm of diameter) were burned in a domestic heating boiler of 25 kW  heat power. The process was performed in two steps: pyrolisis and combustion of wood gas in the nozzle. The boiler was operating without water heat storage. The measurements were taken throughout the entire thermal utilization process including the beginning and the end, when the flame temperature in the nozzle and the boiler water temperature were low and the air excess rate was too high. In this unsteady state the heat efficiency of the boiler was estimated to be about 50%. The following parameters were measured and recorded manually every three minutes: volume stream rate and boiler water temperature, heat quantity obtained by the boiler water, present heat power of the boiler (using an ultrasonic heat meter), flame temperature in the nozzle, temperature of flue gases, carbon monoxide, nitric oxide and oxygen concentrations, air excess rate in the stack (using thermocouples and a gas analyzer with electrochemical cells). The tables show the relationship between the measured values and their influence on the carbon monoxide and nitric oxide concentration values in the flue gases.

Mariusz JOZWIAK, Stanislaw PROSZYK, Witold JABLONSKI:
Influence of urea on the course of the gelation process and the degree of hardening of the adhesive mixture from melamine-urea-formaldehyde resins
(Polish language version)
 

Urea is one of the compounds widely used in the synthesis and modification of amine glues playing a role both as the sorbent of formaldehyde and a buffer substance. The mentioned processes in relation to urea-formaldehyde resin (UF), commonly used in the production of wood-based materials, are relatively well described in literature, while not so commonly used in melamine-urea-formaldehyde resins (MUF). 
This paper covers part of the studies on the effect of urea share  in MUF resin during the hardening process with the use of thermal analysis (DTA, TG, DTG) and upon the degree of its hardening in a glue layer determined by disintegration and washing in boiling water of the granulate fractions. 
Upon analysis of the results, it can be stated, that mass loss occurred also in the early stage of gelation at 30÷80°C, characterised by intense evaporation of volatile constituents such as: water, formaldehyde, and the process increasing polycondensate molecules, as in the final stage of the slow linking of polycondensate at 150÷200°C, characterised by the splitting of low molecular products and cracking of methylenoether bonds. As in the final stage of polycondensate hardening (130÷150°C) there are significant differences in mass losses. At this stage splitting of methylated groups with a release of formaldehyde took place. This process does not occur in the case of linked resin in the presence of urea, which is caused by its reaction with methylolol groups of polycondensate. In the main phase of the gelation process, characterised by the initial resin hardening process and splitting of water at 80÷130°C, distinct differences in mass loss 11.7-7.9% are observed, which can be associated with urea bonding with oligomers of polycondensate. This has been confirmed by other authors on UF resin.  Together with an increase in adding urea and lowering  the gelation temperature of glue mixtures from MUF resin a decrease in the reaction order took place. In the temperature range of 80÷150°C distinct difference (about 42.5%) between mass with 30% additional urea and the comparative system is observed. 
Studies on the degree of MUF resin hardening at 120oC show: urea introduced to glue masses  lowers the degree of hardening of MUF glue , the final hardening degree of MUF glue without additional urea is reached in 60 min and with additional urea reached between 480-960 min.

Vadim GRIGORIEVICH ULASOVEC: 
The volume yield of edged saw-timber acquired from unedged using different methods of log sawing 
(English language version)

The comparative analysis of log-sawing methods has shown that the volume yield of edged saw- timber from unedged, got while sawing the log parallel with the lateral generatrix, is greater than from the boards sawn parallel with the longitudinal log axis.

REPORTS

Wladyslaw STRYKOWSKI, Anna LEWANDOWSKA, Andrzej NOSKOWIAK, Zofia WAWRZYNKIEWICZ: 
Environmental life cycle assessment (LCA) in the wood industry – possibilities and challenges 
(Polish language version) 

The paper concerns an environmental life cycle assessment (LCA) which is a technique of the environmental management used to identify, quantify and assess the environmental burdens generated during the whole life cycle of products. The main aim of the paper is to show the most important methodological and practical aspects occurring in LCA studies that are characteristic for wood industry. LCA can be used 
in wood industry to assess products, services, processes, technological solutions and consumer patterns. Thanks to LCA, the problems can be analyzed from the wide life cycle perspective: from timber production, processing and manufacturing of wood products, the usage stage, to the final disposal. The characteristic point in LCA studies performed for wood products is a positive environmental effect resulted from the photosynthesis and the assimilation of CO2 occurring at the stage of timber production. Thanks to it, reduction of the air pollution is possible. On the other hand,  CO2 emissions occur during the life cycle of wood products what leads to various negative environmental impacts, particularly related to the climate changes. For this reason, in the case of wood products, some kind of the final results correction is needed. The correction is done by comparing the negative and positive effects. In the case of the example presented in the paper (the production of timber - beech wood), the final score for the climate changes equals - 7,22 Pt. The result includes wood production in a forest. The negative sign of the result means the positive environmental effect (the environmental profit). As a next step, the result can be compared with the results for other environmental problems (impact categories) for example land use category. Besides, the considerations on the representativness and data quality related to the wood industry can be found in the paper. The general description of the ecoinvent database and the principal assumptions are presented. It is worth mentioning that the ecoinvent database is one of the largest LCA databases in the world today that includes data covering about 100 different products based on wood. In the paper, the main attention 
is focused on the timber production as a starting point in the life cycle of all products based on wood. The paper is intended to be an introduction to the series of the publications presenting the results of the scientific project Environmental management
 in wood industry by use of the life cycle assessment (LCA)
 has been caring out by the Wood Technology Institute in Poznan. For this reason, in the final part of the paper the general description of the project can be found.  

Sergiusz SUBOCZ: 
Characteristics of forests resources of the Republic of Belarus
(Polish language version)
 

In the article the analysis of the Belarus Republic's forests' condition was presented. It includes characteristics of the forest resources from the point of view of wood volume and age structure as well as method of management and exploitation of forest resources.

ANNOUNCEMENTS 

Przemyslaw GACA: 
The 10th International “Indoor air 2005” Conference
(Polish language version)
 

Indoor air is increasingly recognized as important to our health and well-being, because we spend up to 90% of our time indoors. Since 1978, the series of Indoor Air conferences have been the premiere international meeting place for scientists and professionals in the multidisciplinary field of indoor air sciences. In 4-9th of September the next conference in the series, Indoor Air 2005, was held in Beijing, China. There were described the subjects and current problems connected with indoor air quality and climate presented by the scientists from all over the world.