The use of bio-based materials in buildings has become more and more significant last years.In most of the cases,their health properties and natural provenance have made them a great solution to face global climate wa...The use of bio-based materials in buildings has become more and more significant last years.In most of the cases,their health properties and natural provenance have made them a great solution to face global climate warming and the new policies to reduce building energy consumption.In many thermal problems,biobased materials can allow to optimize the building thermal behavior according to its energy consumption and inside comfort conditions.So it is when they are used as an insulation material in the building.However,it is not the case in this paper.In fact,the bio-based matter is rather used as a desiccant wheel to control air conditioning inside the building.The aim of this paper is to numerically verify if it is possible to use a bed of wood chips as a hygroscopic material(or a desiccant matter)in order to modify the relative humidity inside the building in Reunion Island and so improve thermal comfort.A simple model of heat and mass transfer between a bed of wood chips and building inside air has been set up and implemented into a validated building simulation code named ISOLAB.Numerical simulations were set up for the four climate zones of the island regulations and a focus has been made on the low altitude one(with high,solar irradiation,temperature and relative humidity).Simulation results give the thermal behavior of the building particularly the temperature and relative humidity of inside air temperature,and temperature and moisture content of wood chips.The obtained results lead to determine if the wood chips bed is suitable for the reference building and to verify its technical feasibility(wood species,size of the bed,integration to the building,etc.).The results show that the use of a WCB help to decrease the building inside air temperature and water content up to 10°C less and 11.6 g.kg-1 less.These are the ways to improve inside comfort conditions.Indeed,comfort analysis have shown the possibility to significantly increase building users’thermal comfort when coupled with a fan and natural ventilation,like the regulation needs for low altitude climate.In this case,a gain of 68%of year time is achieved for a building equipped with WCB system compared to one without it(6308 hours of comfort over a year with the WCB against 350 hours without WCB).So the WCB seems to be able to help reducing cooling loads in tropical climate conditions.展开更多
High dimensional stable particlcboards could be produced by usisng saturated steam treated wood chip at elevated pressures. Sample Particleboards were made from wood chip of Birch (Platyphylla). The component changes ...High dimensional stable particlcboards could be produced by usisng saturated steam treated wood chip at elevated pressures. Sample Particleboards were made from wood chip of Birch (Platyphylla). The component changes of steam treated wood chip were analysed by infrared. Infrared spectra demonstrated that the hemicelluloses in steam treated chip were less than those in untreated chip. This is one of the main reasons why steam treatment could improve particlcboard stability. The free radical concentration of steam treated chip surfaces was analysed by ESR spcctroscopy. The results showed that free radical concentration of treated chip surface was higher than that of untreated chip surface. The glueyncss of chip increased and particlcboard resin content decreased.展开更多
Intermodal containers have many advantages in the bulk supply chain, but idle times may cause freezing problems for containers in terminals and long-lasting deliveries, especially during the winter time in Nordic cond...Intermodal containers have many advantages in the bulk supply chain, but idle times may cause freezing problems for containers in terminals and long-lasting deliveries, especially during the winter time in Nordic conditions. The aim of the cold tests was to study metal and composite containers’ ability to tolerate wood chips freezing into the inner surface of the container. Two of the containers were normal metal containers and one was a composite container. The loaded containers were put inside the laboratory hall, the temperature of which was -30°C, and kept there for variable times: less than 24 hours. The inner surface of one of metal containers was treated with a special coolant, EC1. After the test, the chips were unloaded, and the container walls were checked to determine whether there was any material left on them. The test results indicated the advantages of composite containers having a thermally insulated structure without freezing problems. At the same time, chips were freezing badly onto the floor of both metal containers. A frozen chip layer with a thickness of approximately 50 cm - 60 cm was stuck to the floors. As such, EC1 did not seem to prevent the freezing of the chips onto the inner surfaces. The results proved that intermodal logistics of truck and train transportation would be more suitable for composite containers than for metal containers in the winter time in Nordic conditions.展开更多
1 INTRODUCTIONWood chip refining is the most critical step in mechanical pulping.Commercical experi-ences have been gained for years.Modelling and control of chip refiners,however,pose a challenge mainly because of th...1 INTRODUCTIONWood chip refining is the most critical step in mechanical pulping.Commercical experi-ences have been gained for years.Modelling and control of chip refiners,however,pose a challenge mainly because of the stochastic nature of the process.Some attemptshave been made to employ factor analysis technique[1]in the modelling andsimulating of refiner operation[2,3].Strand[2]used common factors as links betweenintrinsic fibre properties and pulp quality.He believed that a qualitative concept onthe physical nature of these common factors could be arrived at,and thus would helpto understand what refining variables need to be controlled or adjusted in order to im-prove pulp quality.However,the linear model used in factor analysis is based on theassumption that the interactions among the system variables are linear,which,ofcourse,is not true in practice.展开更多
Potato is the fifth largest agricultural crop in Canada and contributes to the generation of an abundant amount of potato peel.However,disposal/recycling this peel remains a challenge due to the stringent environmenta...Potato is the fifth largest agricultural crop in Canada and contributes to the generation of an abundant amount of potato peel.However,disposal/recycling this peel remains a challenge due to the stringent environmental regulations.Consequently,there is a lack of an appropriate recycling and valorization methods of potato peel.Gasification is an effective technology for producing syngas and an ecofriendly waste disposal approach.Syngas is an important industrial intermediate to produce synthetic fuels and chemicals.To develop an ecofriendly and cost-effective valorization approach for potato peel,this study used a mixture of woody biomass(i.e.,wood chips)and potato peel to produce syngas by co-gasification using O_(2) as the gasifying agent at a constant equivalence ratio of 0.3 using Aspen Plus simulation software.The influences of gasification temperature and wood chip/potato peel weight ratio on the carbon conversion efficiency(CCE),and product gas composition(molar fraction)and lower heating value(LHV)of product gas were investigated.This simulation indicated that a positive synergistic interaction occurs between wood chips and potato peel in co-gasification process in terms of an increase in CCE by comparing the arithmetic value and real value at all simulated wood chip to potato peel weight ratios(44.9%to 85.8%,46.5%to 76.2%,and 48.1%to 78.6%at ratios of 25:75,50:50,and 75:25,respectively,for wood chips to potato peel).While the molar fraction of H_(2) and CO decreased continuously with increase in the weight percentage of wood chips in the wood chip-potato peel mixture from 0 wt%to 100 wt%(H_(2),at 42.1 mol%to 41.4 mol%;and CO at 44.0 mol%to 40.4 mol%),accompanied by a decrease of the LHV of the product gas(10.3 to 9.78 MJ·Nm^(−3)).The study concluded that co-gasification for producing syngas is feasible and environmental-friendly option to recycle and valorize potato peel.展开更多
Bioconversion of lignocellulose to fermentable sugars is a promising approach to produce potential bio-based energy and chemicals.Pretreatment is the key step to remove or delocalize lignin in lignocellulose,thus impr...Bioconversion of lignocellulose to fermentable sugars is a promising approach to produce potential bio-based energy and chemicals.Pretreatment is the key step to remove or delocalize lignin in lignocellulose,thus improving enzymatic saccharification efficiency.In this study,three kinds of pretreatment methods(ethanol,bisulfite and sulfate)were employed to produce substrates with various lignin contents which were subsequently subjected to biological saccharification processes.Results showed that a lower lignin content led to a higher fermentable sugar yield based on reducing sugar release for all samples.Additionally,the sulfate pretreatment improved the enzymatic saccharification efficiency in a greater extent than the others.Fourier transform infrared(FTIR)spectroscopy confirmed the structure changes during pretreatment.展开更多
On the basis of analyses of service conditions and properties requirements of wood chip cutting knives, an alloying scheme was formulated and a kind of new tool steel was developed. Parameters for its heat treati...On the basis of analyses of service conditions and properties requirements of wood chip cutting knives, an alloying scheme was formulated and a kind of new tool steel was developed. Parameters for its heat treating process and mechanical properties were systematically investigated and optimized. Satisfactory results were obtained on the knives in practice.展开更多
An experimental study was carried out on bricks using local materials in order to take into account the waste wood management to protect the environment and to reduce the cost of the habitat. Chips and sawdust were bu...An experimental study was carried out on bricks using local materials in order to take into account the waste wood management to protect the environment and to reduce the cost of the habitat. Chips and sawdust were built-in clay bricks in order to study their influence on the compressive strength, Young’s modulus and the speed for soundproofing. Testings in compressive strength were made on the parallelepiped clay bricks, stabilized with different percentages of cement, with incorporation to various percentages of sawdust or wood chips (Mahogany), using a universal press. Young’s modulus was measured from the speed of sound by the ultrasonic method. The results obtained show that the incorporation of mahogany tree chips in the stabilized brick at 8% of cement, does not have much effect on the compressive strength. It was found that the incorporation of chips or sawdust on the clay brick, does not improve the compressive strength. The Young’s modulus decreases with increasing content of sawdust and practically remains constant regardless of the content of chips at 4% and 6% of cement. The clay brick mixed with 8% of mahogany sawdust can be an acoustic barrier.展开更多
An analogy between water flux and the field of temperature gradient in a column of wood fuel chips was discovered by these experiments.The heat-mass transfer coeffieient was deter-mined by least squares method.An equa...An analogy between water flux and the field of temperature gradient in a column of wood fuel chips was discovered by these experiments.The heat-mass transfer coeffieient was deter-mined by least squares method.An equation relating water flux and tempetature gradient was devel-opcd and it was demonstrated that the tempeature gradient was the main driving force for watertransport.The meehanism was evaporation-condensation of water vaor through natural convcctionin air phase.The study gives a theoretical exlanation for analyzing the problem of water transport inwood particle material.展开更多
In this research, a series of wood-based panels were produced by using wood chips [beech (Fagus Sylvatica L.) and Scotch pine (Pinus sylvestris L.)] as wastes of wood-working workshops and acrylic fibers as wastes of ...In this research, a series of wood-based panels were produced by using wood chips [beech (Fagus Sylvatica L.) and Scotch pine (Pinus sylvestris L.)] as wastes of wood-working workshops and acrylic fibers as wastes of textiles factory. Four kinds of different panels (Eltapan I, II, III and IV) were obtained by mixing these components in different composition (0%, 25% and 50%). Some physical and mechanical properties of the samples taken from these panels were determined in accordance with ASTM D1037-12 and ASTM-C 1113. The values were compared to properties of industrially produced chipboard. As a result, the textile fibers used as additive material reduced density, thermal conductivity and bending resistance of wood panel and increased dimensional stability of wood panel.展开更多
This study includes the manufacture of cement stabilized clay bricks with embedded mahogany chips. The impact of this waste and its interaction with water in the bricks was evaluated on the mechanical properties. The ...This study includes the manufacture of cement stabilized clay bricks with embedded mahogany chips. The impact of this waste and its interaction with water in the bricks was evaluated on the mechanical properties. The compressive strength tests using a universal press were carried out on bricks with and without adding wood chips. The results obtained show that the incorporation of wood chips into the bricks decreases the compressive strength. This reduction in compressive strength led us to conduct an analysis of clay and water as intrinsic factors, before and after incorporation of untreated wood waste. Thus, a mineralogical analysis of the clay with and without mahogany chips was made using an X-ray diffractometer, using an anticathode of cobalt with the line Κα, of wavelength λ = 1789Å. After quantification of the mineral constituents, it is noted that the concentration of SiO2 decreases considerably in the clay with addition of wood chips, resulting in the reduction of the compressive strength in these composite materials (from Rc = 9.26 MPa at 0% of chips to 3.55 MPa at 8%). A mathematical model following the interpolations of Lagrange was then proposed. The analysis of the water resulting from the impregnation of dry wood chips in the water, shows that the water becomes strongly acid (pH = 4.3 at the 7th day of immersion), thus contributing to the reduction of resistance. This analysis of intrinsic factors will allow future studies to take into account the treatment of wood waste by different processes in order to increase the mechanical, thermal and acoustic properties of composite bricks with the same contents, thus generating massive support for the use of its composite materials.展开更多
文摘The use of bio-based materials in buildings has become more and more significant last years.In most of the cases,their health properties and natural provenance have made them a great solution to face global climate warming and the new policies to reduce building energy consumption.In many thermal problems,biobased materials can allow to optimize the building thermal behavior according to its energy consumption and inside comfort conditions.So it is when they are used as an insulation material in the building.However,it is not the case in this paper.In fact,the bio-based matter is rather used as a desiccant wheel to control air conditioning inside the building.The aim of this paper is to numerically verify if it is possible to use a bed of wood chips as a hygroscopic material(or a desiccant matter)in order to modify the relative humidity inside the building in Reunion Island and so improve thermal comfort.A simple model of heat and mass transfer between a bed of wood chips and building inside air has been set up and implemented into a validated building simulation code named ISOLAB.Numerical simulations were set up for the four climate zones of the island regulations and a focus has been made on the low altitude one(with high,solar irradiation,temperature and relative humidity).Simulation results give the thermal behavior of the building particularly the temperature and relative humidity of inside air temperature,and temperature and moisture content of wood chips.The obtained results lead to determine if the wood chips bed is suitable for the reference building and to verify its technical feasibility(wood species,size of the bed,integration to the building,etc.).The results show that the use of a WCB help to decrease the building inside air temperature and water content up to 10°C less and 11.6 g.kg-1 less.These are the ways to improve inside comfort conditions.Indeed,comfort analysis have shown the possibility to significantly increase building users’thermal comfort when coupled with a fan and natural ventilation,like the regulation needs for low altitude climate.In this case,a gain of 68%of year time is achieved for a building equipped with WCB system compared to one without it(6308 hours of comfort over a year with the WCB against 350 hours without WCB).So the WCB seems to be able to help reducing cooling loads in tropical climate conditions.
文摘High dimensional stable particlcboards could be produced by usisng saturated steam treated wood chip at elevated pressures. Sample Particleboards were made from wood chip of Birch (Platyphylla). The component changes of steam treated wood chip were analysed by infrared. Infrared spectra demonstrated that the hemicelluloses in steam treated chip were less than those in untreated chip. This is one of the main reasons why steam treatment could improve particlcboard stability. The free radical concentration of steam treated chip surfaces was analysed by ESR spcctroscopy. The results showed that free radical concentration of treated chip surface was higher than that of untreated chip surface. The glueyncss of chip increased and particlcboard resin content decreased.
文摘Intermodal containers have many advantages in the bulk supply chain, but idle times may cause freezing problems for containers in terminals and long-lasting deliveries, especially during the winter time in Nordic conditions. The aim of the cold tests was to study metal and composite containers’ ability to tolerate wood chips freezing into the inner surface of the container. Two of the containers were normal metal containers and one was a composite container. The loaded containers were put inside the laboratory hall, the temperature of which was -30°C, and kept there for variable times: less than 24 hours. The inner surface of one of metal containers was treated with a special coolant, EC1. After the test, the chips were unloaded, and the container walls were checked to determine whether there was any material left on them. The test results indicated the advantages of composite containers having a thermally insulated structure without freezing problems. At the same time, chips were freezing badly onto the floor of both metal containers. A frozen chip layer with a thickness of approximately 50 cm - 60 cm was stuck to the floors. As such, EC1 did not seem to prevent the freezing of the chips onto the inner surfaces. The results proved that intermodal logistics of truck and train transportation would be more suitable for composite containers than for metal containers in the winter time in Nordic conditions.
文摘1 INTRODUCTIONWood chip refining is the most critical step in mechanical pulping.Commercical experi-ences have been gained for years.Modelling and control of chip refiners,however,pose a challenge mainly because of the stochastic nature of the process.Some attemptshave been made to employ factor analysis technique[1]in the modelling andsimulating of refiner operation[2,3].Strand[2]used common factors as links betweenintrinsic fibre properties and pulp quality.He believed that a qualitative concept onthe physical nature of these common factors could be arrived at,and thus would helpto understand what refining variables need to be controlled or adjusted in order to im-prove pulp quality.However,the linear model used in factor analysis is based on theassumption that the interactions among the system variables are linear,which,ofcourse,is not true in practice.
基金funding provided through the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery grant and as the University of Prince Edward Island start up award to Yulin Hu.
文摘Potato is the fifth largest agricultural crop in Canada and contributes to the generation of an abundant amount of potato peel.However,disposal/recycling this peel remains a challenge due to the stringent environmental regulations.Consequently,there is a lack of an appropriate recycling and valorization methods of potato peel.Gasification is an effective technology for producing syngas and an ecofriendly waste disposal approach.Syngas is an important industrial intermediate to produce synthetic fuels and chemicals.To develop an ecofriendly and cost-effective valorization approach for potato peel,this study used a mixture of woody biomass(i.e.,wood chips)and potato peel to produce syngas by co-gasification using O_(2) as the gasifying agent at a constant equivalence ratio of 0.3 using Aspen Plus simulation software.The influences of gasification temperature and wood chip/potato peel weight ratio on the carbon conversion efficiency(CCE),and product gas composition(molar fraction)and lower heating value(LHV)of product gas were investigated.This simulation indicated that a positive synergistic interaction occurs between wood chips and potato peel in co-gasification process in terms of an increase in CCE by comparing the arithmetic value and real value at all simulated wood chip to potato peel weight ratios(44.9%to 85.8%,46.5%to 76.2%,and 48.1%to 78.6%at ratios of 25:75,50:50,and 75:25,respectively,for wood chips to potato peel).While the molar fraction of H_(2) and CO decreased continuously with increase in the weight percentage of wood chips in the wood chip-potato peel mixture from 0 wt%to 100 wt%(H_(2),at 42.1 mol%to 41.4 mol%;and CO at 44.0 mol%to 40.4 mol%),accompanied by a decrease of the LHV of the product gas(10.3 to 9.78 MJ·Nm^(−3)).The study concluded that co-gasification for producing syngas is feasible and environmental-friendly option to recycle and valorize potato peel.
基金support from National Training Programs of Innovation and Entrepreneurship for Undergraduates(Qilu University of Technology)National Science Foundation of China(Grant Nos.31670584,31500490).
文摘Bioconversion of lignocellulose to fermentable sugars is a promising approach to produce potential bio-based energy and chemicals.Pretreatment is the key step to remove or delocalize lignin in lignocellulose,thus improving enzymatic saccharification efficiency.In this study,three kinds of pretreatment methods(ethanol,bisulfite and sulfate)were employed to produce substrates with various lignin contents which were subsequently subjected to biological saccharification processes.Results showed that a lower lignin content led to a higher fermentable sugar yield based on reducing sugar release for all samples.Additionally,the sulfate pretreatment improved the enzymatic saccharification efficiency in a greater extent than the others.Fourier transform infrared(FTIR)spectroscopy confirmed the structure changes during pretreatment.
文摘On the basis of analyses of service conditions and properties requirements of wood chip cutting knives, an alloying scheme was formulated and a kind of new tool steel was developed. Parameters for its heat treating process and mechanical properties were systematically investigated and optimized. Satisfactory results were obtained on the knives in practice.
文摘An experimental study was carried out on bricks using local materials in order to take into account the waste wood management to protect the environment and to reduce the cost of the habitat. Chips and sawdust were built-in clay bricks in order to study their influence on the compressive strength, Young’s modulus and the speed for soundproofing. Testings in compressive strength were made on the parallelepiped clay bricks, stabilized with different percentages of cement, with incorporation to various percentages of sawdust or wood chips (Mahogany), using a universal press. Young’s modulus was measured from the speed of sound by the ultrasonic method. The results obtained show that the incorporation of mahogany tree chips in the stabilized brick at 8% of cement, does not have much effect on the compressive strength. It was found that the incorporation of chips or sawdust on the clay brick, does not improve the compressive strength. The Young’s modulus decreases with increasing content of sawdust and practically remains constant regardless of the content of chips at 4% and 6% of cement. The clay brick mixed with 8% of mahogany sawdust can be an acoustic barrier.
文摘An analogy between water flux and the field of temperature gradient in a column of wood fuel chips was discovered by these experiments.The heat-mass transfer coeffieient was deter-mined by least squares method.An equation relating water flux and tempetature gradient was devel-opcd and it was demonstrated that the tempeature gradient was the main driving force for watertransport.The meehanism was evaporation-condensation of water vaor through natural convcctionin air phase.The study gives a theoretical exlanation for analyzing the problem of water transport inwood particle material.
文摘In this research, a series of wood-based panels were produced by using wood chips [beech (Fagus Sylvatica L.) and Scotch pine (Pinus sylvestris L.)] as wastes of wood-working workshops and acrylic fibers as wastes of textiles factory. Four kinds of different panels (Eltapan I, II, III and IV) were obtained by mixing these components in different composition (0%, 25% and 50%). Some physical and mechanical properties of the samples taken from these panels were determined in accordance with ASTM D1037-12 and ASTM-C 1113. The values were compared to properties of industrially produced chipboard. As a result, the textile fibers used as additive material reduced density, thermal conductivity and bending resistance of wood panel and increased dimensional stability of wood panel.
文摘This study includes the manufacture of cement stabilized clay bricks with embedded mahogany chips. The impact of this waste and its interaction with water in the bricks was evaluated on the mechanical properties. The compressive strength tests using a universal press were carried out on bricks with and without adding wood chips. The results obtained show that the incorporation of wood chips into the bricks decreases the compressive strength. This reduction in compressive strength led us to conduct an analysis of clay and water as intrinsic factors, before and after incorporation of untreated wood waste. Thus, a mineralogical analysis of the clay with and without mahogany chips was made using an X-ray diffractometer, using an anticathode of cobalt with the line Κα, of wavelength λ = 1789Å. After quantification of the mineral constituents, it is noted that the concentration of SiO2 decreases considerably in the clay with addition of wood chips, resulting in the reduction of the compressive strength in these composite materials (from Rc = 9.26 MPa at 0% of chips to 3.55 MPa at 8%). A mathematical model following the interpolations of Lagrange was then proposed. The analysis of the water resulting from the impregnation of dry wood chips in the water, shows that the water becomes strongly acid (pH = 4.3 at the 7th day of immersion), thus contributing to the reduction of resistance. This analysis of intrinsic factors will allow future studies to take into account the treatment of wood waste by different processes in order to increase the mechanical, thermal and acoustic properties of composite bricks with the same contents, thus generating massive support for the use of its composite materials.
