The mechanism of gold lock-up in refractory wood chips

Abstract - There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.

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The Operating Experiences Using Low Bulk Wood Chips

JAPAN TAPPI JOURNAL ◽

10.2524/jtappij.60.1038 ◽

2006 ◽

Vol 60 (7) ◽

pp. 1038-1042 ◽

Cited By ~ 2

Author(s):

Ryuuichi Suzumi

Keyword(s):

Wood Chips

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Sawmill worker killed while unplugging wood chips from a chipper duct.

10.26616/nioshsface98ia075 ◽

1999 ◽

Keyword(s):

Wood Chips

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A complementary analysis of the porous structure of biochars obtained from biomass

Carbon letters ◽

10.1007/s42823-019-00101-4 ◽

2019 ◽

Vol 30 (3) ◽

pp. 325-329 ◽

Cited By ~ 1

Author(s):

Mirosław Kwiatkowski ◽

Dimitrios Kalderis

Keyword(s):

Structural Analysis ◽

Porous Structure ◽

Rice Husk ◽

Wood Chips ◽

Complementary Information ◽

Analysis Methods ◽

Eucalyptus Wood ◽

Adsorptive Properties ◽

Complementary Analysis ◽

Carbonaceous Adsorbent

Abstract This paper presents the results of the analysis of the porous structure of biochars produced from biomass, namely eucalyptus, wood chips, pruning waste and rice husk. The structural analysis was carried out using the BET, the t-plot, the NLDFT and the LBET methods, which yielded not only complementary information on the adsorptive properties of obtained biochars from these materials, but also information on the usefulness of the structural analysis methods in question for the research into an effect of the technology of carbonaceous adsorbent preparation.

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Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽

10.3390/en12091590 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1590 ◽

Cited By ~ 9

Author(s):

Angelo Del Giudice ◽

Andrea Acampora ◽

Enrico Santangelo ◽

Luigi Pari ◽

Simone Bergonzoli ◽

...

Keyword(s):

Moisture Content ◽

Power Plants ◽

Black Locust ◽

Thermal Power ◽

Initial Moisture Content ◽

Wood Chip ◽

Wood Chips ◽

Cocurrent Flow ◽

Drying Process ◽

Rotary Dryer

Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kgdry solids−1 (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

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Improvement of Enzymatic Saccharification of Cellulose-Containing Raw Materials Using Aspergillus niger

Processes ◽

10.3390/pr9081360 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1360

Author(s):

Ekaterina Budenkova ◽

Stanislav Sukhikh ◽

Svetlana Ivanova ◽

Olga Babich ◽

Vyacheslav Dolganyuk ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Aspergillus Niger ◽

Filter Paper ◽

Raw Materials ◽

Enzymatic Saccharification ◽

Wood Chip ◽

Cellulase Activity ◽

Wood Chips ◽

Acid Pretreatment ◽

Hydrolysis Of

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.

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Parameters of Trucks and Loads in the Transport of Scots Pine Wood Biomass Depending on the Season and Moisture Content of the Load

Forests ◽

10.3390/f12020223 ◽

2021 ◽

Vol 12 (2) ◽

pp. 223

Author(s):

Grzegorz Trzciński ◽

Łukasz Tymendorf ◽

Paweł Kozakiewicz

Keyword(s):

Moisture Content ◽

Bulk Density ◽

Load Capacity ◽

Wood Chips ◽

Total Weight ◽

Wood Biomass ◽

Four Seasons ◽

Gross Vehicle Weight ◽

Bulk Volume ◽

Average Quantity

Transport of wood biomass is one of the key operations in forestry and in the wood industry. An important part is the transport of shredded wood, where the most common forms are chips and sawdust. The aim of the research was to present the variability of the total weight of trucks (gross vehicle weight, GVW), the weight of the empty trucks (tare), and loads of chips and sawdust in different periods of the year. Changes in specific parameters were analyzed: GVW; tare weight; trailer capacity; use of the trailer load capacity; bulk volume and bulk density of wood biomass loads; solid cubic meter (m3) and weight of 1m3 of the load; and load weight depending on the season, with simultaneous measurements of wood chips and sawdust moisture. More than 250 transports from four seasons of the year were analyzed in the research. It was found that the total weight of trucks (GVW) was at a comparable level, on average from 39.42 to 39.64 Mg with slight differences (with SD 0.29 and 0.39). The weight of empty trucks was 16.15 Mg for chip-bearing trucks and 15.93 Mg for sawdust-bearing trucks (with SD 0.604 and 0.526). The type of wood material has an influence on the transported volume. The average quantity of load in the bulk cubic meter was 64.783 m3 for wood chips (SD 3.127) and 70.465 m3 (SD 2.516) for sawdust. Over 30% differences in the volume of transported wood chips and approximately 18% for sawdust were observed. The use of the loading capacity of the trailer was on average 72.58% (SD 5.567) for the transport of wood chips and 77.42% (SD 3.019) for the transport of sawdust. The sawdust bulk density was from 0.3050 to 0.4265 Mg⋅m−3 for wood chips and 0.3200 to 0.3556 Mg⋅m−3 for sawdust. This parameter is significantly dependent on moisture content, and the determined correlation functions can be used for estimating and predicting bulk density. The abovementioned absolute moisture content of chips and sawdust also depends on the season, which also affects the selected parameters of wood biomass loads.

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Effects of microwave irradiation on the moisture content of various wood chip fractions obtained from different tree species

Journal of Wood Science ◽

10.1186/s10086-021-01958-8 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Monika Aniszewska ◽

Krzysztof Słowiński ◽

Ewa Tulska ◽

Witold Zychowicz

Keyword(s):

Moisture Content ◽

Microwave Irradiation ◽

Microwave Power ◽

Irradiation Time ◽

Initial Moisture Content ◽

Radiant Energy ◽

Wood Chip ◽

Wood Chips ◽

Chip Size ◽

Drying Rates

AbstractThe paper proposes the use of microwave irradiation to lower the initial moisture content of wood chips. The study involved willow and fir chips fractionated by means of a sieve separator and unfractionated ash chips. The wood chips were exposed to a constant microwave power of 800 W for 30 s, 60 s, 120 s and 180 s. The chips were weighed before and after irradiation to measure loss of moisture. It was found that the decline in moisture content increased with wood chip size for a given irradiation time and microwave power. The initial moisture content of wood chips was not found to significantly affect loss of moisture as the drying rates of wood chips with higher and lower moisture content exposed to microwaves were not statistically different. The results showed that irradiation intensity increased with the time of exposure to microwaves and unit radiant energy per unit of evaporated moisture decreased with increasing wood chip size in the 3.15–31.50 mm range.

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Development of a New Sensor Module for an Enhanced Fuel Flexible Operation of Biomass Boilers

Processes ◽

10.3390/pr9040661 ◽

2021 ◽

Vol 9 (4) ◽

pp. 661

Author(s):

Martin Meiller ◽

Jürgen Oischinger ◽

Robert Daschner ◽

Andreas Hornung

Keyword(s):

Particle Size ◽

Bulk Material ◽

Detection System ◽

Wood Chips ◽

Convective Drying ◽

Characteristic Functions ◽

Biomass Combustion ◽

Fuel Flexibility ◽

Sensor Module ◽

Over Time

The heterogeneity of biogenic fuels, and especially biogenic residues with regard to water and ash content, particle size and particle size distribution is challenging for biomass combustion, and limits fuel flexibility. Online fuel characterization as a part of process control could help to optimize combustion processes, increase fuel flexibility and reduce emissions. In this research article, a concept for a new sensor module is presented and first tests are displayed to show its feasibility. The concept is based on the principle of hot air convective drying. The idea is to pass warm air with 90 °C through a bulk of fuel like wood chips and measure different characteristics such as moisture, temperatures and pressure drop over the bulk material as a function over time. These functions are the basis to draw conclusions and estimate relevant fuel properties. To achieve this goal, a test rig with a volume of 0.038 m3 was set up in the laboratory and a series of tests was performed with different fuels (wood chips, saw dust, wood pellets, residues from forestry, corn cobs and biochar). Further tests were carried out with conditioned fuels with defined water and fines contents. The experiments show that characteristic functions arise over time. The central task for the future will be to assign these functions to specific fuel characteristics. Based on the data, the concept for a software for an automated, data-based fuel detection system was designed.

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Isothermal Kinetic Analysis of the Thermal Decomposition of Wood Chips from an Apple Tree

Processes ◽

10.3390/pr9020195 ◽

2021 ◽

Vol 9 (2) ◽

pp. 195

Author(s):

Ivan Vitázek ◽

Martin Šotnar ◽

Stella Hrehová ◽

Kristína Darnadyová ◽

Jan Mareček

Keyword(s):

Thermal Decomposition ◽

Apple Tree ◽

Combustion Process ◽

Reaction Model ◽

Wood Chips ◽

Small Scale ◽

Exponential Factor ◽

Air Atmosphere ◽

First Order Chemical Reaction ◽

Isothermal Kinetic

The thermal decomposition of wood chips from an apple tree is studied in a static air atmosphere under isothermal conditions. Based on the thermogravimetric analysis, the values of the apparent activation energy and pre-exponential factor are 34 ± 3 kJ mol−1 and 391 ± 2 min−1, respectively. These results have also shown that this process can be described by the rate of the first-order chemical reaction. This reaction model is valid only for a temperature range of 250–290 °C, mainly due to the lignin decomposition. The obtained results are used for kinetic prediction, which is compared with the measurement. The results show that the reaction is slower at higher values of degree of conversion, which is caused by the influence of the experimental condition. Nevertheless, the obtained kinetic parameters could be used for the optimization of the combustion process of wood chips in small-scale biomass boilers.

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