scholarly journals Uncertainty Simulation of Wood Chipping Operation for Bioenergy Based on Queuing Theory

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 822
Author(s):  
Yoshida ◽  
Takata
Keyword(s):  
Supply Chain ◽  
Moisture Content ◽  
Queuing Theory ◽  
Wood Chip ◽  
Stochastic Modelling ◽  
Simulation Method ◽  
Daily Production ◽  
Deterministic Simulation ◽  
Loss Compensation ◽  
Truck Arrival

Managing uncertainty is the way to secure stability of the supply chain. Uncertainty within chipping operation and chip transportation causes production loss. In the wood chip supply chain for bioenergy, operational uncertainty mainly appears in the moisture content of the material, chipping productivity, and the interval of truck arrival. This study theoretically quantified the loss in wood chip production by applying queuing theory and stochastic modelling. As well as the loss in production, the inefficiency was identified as the idling time of chipper and the queuing time of trucks. The aim of this study is to quantify the influence of three uncertainties on wood chip production. This study simulated the daily chip production using a mobile chipper by applying queuing theory and stochastic modelling of three uncertainties. The result was compared with the result of deterministic simulation which did not consider uncertainty. Uncertainty reduced the production by 14% to 27% compared to the production of deterministic simulation. There were trucks scheduled but not used. The cases using small trucks show the largest daily production amount, but their lead time was the longest. The large truck was sensitive to the moisture content of material because of the balance between payload and volumetric capacity. This simulation method can present a possible loss in production amount and enables to evaluate some ways for the loss compensation quantitatively such as outsourcing or storing buffer. For further development, the data about the interval of truck arrival should be collected from fields and analyzed. We must include the other uncertainties causing technical and operator delays.

scholarly journals Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1590 ◽  
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.

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

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.

scholarly journals Electrical Capacitance Characteristics of Wood Chips at Low Frequency Ranges: A Cheap Tool for Quality Assessment

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3494
Author(s):  
Jakub Lev ◽  
Václav Křepčík ◽  
Egidijus Šarauskis ◽  
František Kumhála
Keyword(s):  
Moisture Content ◽  
Linear Models ◽  
Economic Value ◽  
Wood Chip ◽  
Principal Component ◽  
Dissipation Factor ◽  
Industrial Applications ◽  
Wood Chips ◽  
Electrical Capacitance ◽  
Low Frequencies

Moisture content is one of the most important parameters related to the quality of wood chips that affects both the calorific and economic value of fuel chips. For industrial applications, moisture content needs to be detected quickly. For this purpose, various indirect moisture content measurement methods (e.g., capacitance, NIR, microwave, ECT, X-ray CT, and nuclear MR) have been investigated with different results in the past. Nevertheless, determining wood chip moisture content in real time is still a challenge. The main aim of this article was therefore to analyze the dielectric properties of wood chips at low frequencies (10 kHz–5 MHz) and to examine the possibility of using these properties to predict wood chip moisture content and porosity. A container-type probe was developed for this purpose. The electrical capacitance and dissipation factor of wood chips with different moisture content was measured by an LCR meter at 10 kHz, 50 kHz, 100 kHz, 500 kHz, 1 MHz, and 5 MHz frequencies. Wood chip porosity was also measured using a gas displacement method. Linear models for moisture content and porosity prediction were determined by backward stepwise linear regression. Mathematical model was developed to better understand the physical relationships between moisture content, porosity, and electrical capacitance. These models were able to predict the moisture content of observed quantities of wood chips with the required accuracy (R2 = 0.9−0.99). This finding opens another path to measuring the moisture content and porosity of wood chips in a relatively cheap and fast way and with adequate precision. In addition, principal component analysis showed that it is also possible to distinguish between individual wood chip fraction sizes from the information obtained.

scholarly journals Improving Margins of the Indonesian Seaweed Supply Chain Upstream Players: The application of the Kaizen Approach

2021 ◽  
Vol 226 ◽  
pp. 00004
Author(s):  
Agus Heri Purnomo ◽  
Rinta Kusumawati ◽  
Asri Pratitis ◽  
Ilham Alimin ◽  
Singgih Wibowo ◽  
...  
Keyword(s):  
Supply Chain ◽  
Moisture Content ◽  
Business Development ◽  
External Factors ◽  
Analysis Approach ◽  
Problem Analysis

The margin obtained at the upstream in the Indonesian commercial seaweed supply chain is generally small and makes the motivation for business development low. The research aimed to identify the opportunities to overcome these problems. The research conducted with the Kaizen analysis approach that seven upstream business nodes were chosen at three locations: two Gracilaria sp. farmers and one Gracilaria sp. trader in Brebes, one Eucheumatoid farmer and one intermediary trader in Serang, also two Eucheumatoid farmers in Sumenep. The results show some inefficiency in several loci in the business lines of intermediate farmers and traders. These include a gap on moisture content (Gracilaria of 2 % and Eucheumatoid of 4 %), productivity of Gracilaria pond 0.6 t ha–1 yr–1 and its by-product is 50 %, while the productivity of Eucheumatoids was 10 %. The quality of dry Gracilaria is one grade only. All result loss of potential margin. Root problem analysis found several external factors outside the Kaizen domain and other internal aspects can be corrected through intervention. The Kaizen analysis determined some simple interventions including improvement of cultivation embankments and extension of maintenance periods, use of monofilament net to dry seaweed, optimization of cultivation spacing, and use of moisture checker.

scholarly journals A review: hybrid simulation in forestry supply chain

2021 ◽  
Vol 912 (1) ◽  
pp. 012009
Author(s):  
N Sembiring ◽  
H L Napitupulu ◽  
M T Sembiring ◽  
A Ishak ◽  
F Irwany
Keyword(s):  
Supply Chain ◽  
Experimental Testing ◽  
Hybrid Simulation ◽  
Simulation Method ◽  
Scientific Article ◽  
Supply Chain Network ◽  
Supply Chain Optimization ◽  
Production Methods ◽  
Time Period ◽  
Forestry Sector

Abstract Changes in supply chain availability in the forestry sector can significantly change efficiency responsiveness. This forestry supply chain network involves various processes such as harvesting, energy generation, wood, paper and board production. Methods that can be used to perform supply chain optimization are hybrid modelling and simulation. Substructure techniques with experimental testing methods that target numerical component conductors with communication loop components as well as transfer systems to form an entire system commonly referred to as Hybrid Simulation. In this study, we aim to find solutions so that the supply chain network in the forestry sector is not cut off by using hybrid simulation method. Hybrid simulations used can take into account when the supply chain will run out and prevent excessive exploitation so as to repair damage and recycle the supply chain so that it is not disconnected until the time period is taken into account. Each scientific article is rigorously selected to obtain articles that align with the purpose of this research.

Measurement of Bulk Electrical Properties Using GPR with a Variable Reflector

2018 ◽  
Vol 23 (4) ◽  
pp. 489-496
Author(s):  
J. David Redman ◽  
A. Peter Annan ◽  
Nectaria Diamanti
Keyword(s):  
Electrical Properties ◽  
Moisture Content ◽  
Ground Penetrating Radar ◽  
Arrival Time ◽  
Wood Chip ◽  
Direct Wave ◽  
Trace Data ◽  
Ground Penetrating ◽  
Prototype Instrument

Bulk electrical properties of media are important inherently for ground penetrating radar (GPR) applications and for providing a means to determine indirectly other physical properties such as moisture content. We have developed a reflector whose reflectivity can be controlled electronically. This variable reflector controlled by a GPR provides an effective method to measure bulk electrical properties of media. For sample measurements, the GPR is placed on one side of a sample and the variable reflector on the opposite side. GPR trace data are then acquired with the reflector in an on-state and in the off-state. By differencing these measurements, we improve the ability to detect the specific reflection event from the variable reflector. This process removes both the direct wave and clutter from the trace data, improving the quality of the refection event and our ability to accurately pick its arrival time and amplitude. We describe the variable reflector, a prototype instrument based on the reflector and numerical modeling performed to understand its response. We also show the results of testing applications to the measurement of wood chip moisture content and monitoring of the electrical properties of concrete during the curing process.

Simulation of M/M/1 Queue Model Based on WITNESS

2011 ◽  
Vol 261-263 ◽  
pp. 753-756
Author(s):  
Hua Meng ◽  
Hua Wang ◽  
Jian Jun Wang
Keyword(s):  
Complex System ◽  
Production Line ◽  
Queuing Theory ◽  
Simulation Method ◽  
System Optimization ◽  
Theory Method ◽  
Steel Making ◽  
Queue Model ◽  
System Characteristics ◽  
Static Simulation

The techno-interface of BF-BOF region is an important stage that connects iron making procedure with steel making procedure in the production line, acting as a connecting link between the preceding and the following procedure. It is also the key region to optimize the iron making and steel making process as a whole. In this paper, based on queuing theory method for BF-BOF region simulation, a static simulation method is presented to realize the simulation of dynamic system, WITNESS is used to simulate the M/M/1 queue model. The number of different transportation ladles has been analyzed to influence the BF-BOF region, the best ladles were obtained in order to improve production rate. The results show that the modeling method can reflect the complex system characteristics of BF-BOF region and provide the advice for system optimization.

scholarly journals Simulation of Boarding Time Prediction using M/M/C/K Queuing Model for Airport Passengers

2019 ◽  
Vol 8 (4) ◽  
pp. 5863-5867
Keyword(s):  
Queuing Theory ◽  
Minimum Cost ◽  
Simulation Method ◽  
Comfort Level ◽  
Mathematical Methods ◽  
Queuing Model ◽  
Security Systems ◽  
Analytical Result ◽  
Scheduled Time ◽  
Good Agreement

Successfully executing takeoff of an aircraft as per the scheduled time is mainly depends on how effectively various queues of different security systems in the airport is managed. Recently, due to the globalization, air traffic is increasing exponentially. Number of passengers handled by airport authorities in various queues with minimum waiting time of the passenger in queues is need of the hour. Queuing theory concepts and the mathematical models already developed are used to optimize largely in airports. However the congestion in the airports is ever increasing and need computation to arrive at quick decision to handle such situations with minimum cost while not compromising the passengers comfort level. In a typical airport, starting from the entry gate to exit gate, passengers need to experience various types of queues. However the queuing system which is selected for boarding in a aircraft is most critical and aircraft operator need to address the queue properly, to takeoff the aircraft at right time. In this work boarding time is predicted using simulation method and is compared with that of mathematical methods. The simulated results are in good agreement with that of analytical result.

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