Modeling Harvest Forest Residue Collection for Bioenergy Production

Forest harvest residues are often available at roadside landings as a byproduct of the log manufacturing process. This residue is usually available for renewable energy production if desired, however there is a significant amount of residues that do not reach the landing during the harvesting process and could potentially increase the supply of forest biomass from each harvest unit. The proportion of recoverable residues depends on their collection costs, which are a function of the distance from roadside landing, terrain conditions, and collection method. In this study, a forest residue collection model using forwarders and excavator-base loaders was developed to estimate the potential cost of biomass extraction from the forest to roadside landings. At the operational level, the model calculates the potential forwarder paths to estimate the cost depending on slope, machine arrangement and distance. For the analyzed harvest unit, the use of the excavator-base loader working alone is the most cost effective system for distances of less than 50 m and two forwarders and one excavator-base loader is the most cost effective system for distances beyond 50 m. The optimal solution collection costs ranged from USD 7.2 to 27.5 per oven-dry tonne for a range of distance between 15 and 350 m. The use of one operator to trade positions as forwarder operator and excavator-base loader operator resulted in lower productivity and higher cost compared to the use of a separate operator for each machine

Are double trailers cost effective for transporting forest biomass on steep terrain?

Transportation of forest biomass on steep terrain involves logistical challenges. Trucks with large single trailers are often unable to travel on forest roads due to their narrowness, tight curves, adverse grades and limited areas to turn around. A shorter trailer must be used but then transportation capacity is limited by the trailer volume due to the low bulk density of the processed biomass, particularly when the biomass is dry. With double trailers, transportation capacity can be limited by allowable legal weight based on axle number and spacing. We developed a simulation model that explores the economic feasibility of using double-trailer configurations to transport forest biomass to a bioenergy facility from the grinder at a landing or from a centralized yard in Washington, Oregon and California. Results show that double trailers can be a cost effective alternative to single trailers under limited conditions in Oregon and Washington, but they are not a competitive option in California due to the state's transportation regulations

Are double trailers cost effective for transporting forest biomass on steep terrain?

Transportation of forest biomass on steep terrain involves logistical challenges. Trucks with large single trailers are often unable to travel on forest roads due to their narrowness, tight curves, adverse grades and limited areas to turn around. A shorter trailer must be used but then transportation capacity is limited by the trailer volume due to the low bulk density of the processed biomass, particularly when the biomass is dry. With double trailers, transportation capacity can be limited by allowable legal weight based on axle number and spacing. We developed a simulation model that explores the economic feasibility of using double-trailer configurations to transport forest biomass to a bioenergy facility from the grinder at a landing or from a centralized yard in Washington, Oregon and California. Results show that double trailers can be a cost effective alternative to single trailers under limited conditions in Oregon and Washington, but they are not a competitive option in California due to the state's transportation regulations

Are double trailers cost effective for transporting forest biomass on steep terrain?

Transportation of forest biomass on steep terrain involves logistical challenges. Trucks with large single trailers are often unable to travel on forest roads due to their narrowness, tight curves, adverse grades and limited areas to turn around. A shorter trailer must be used but then transportation capacity is limited by the trailer volume due to the low bulk density of the processed biomass, particularly when the biomass is dry. With double trailers, transportation capacity can be limited by allowable legal weight based on axle number and spacing. We developed a simulation model that explores the economic feasibility of using double-trailer configurations to transport forest biomass to a bioenergy facility from the grinder at a landing or from a centralized yard in Washington, Oregon and California. Results show that double trailers can be a cost effective alternative to single trailers under limited conditions in Oregon and Washington, but they are not a competitive option in California due to the state's transportation regulations

Decision support for forest harvest residue collection

Forest harvest residues are often available at roadside landings as a byproduct of the log manufacturing process. This residue is usually available for renewable energy production if desired, however there is a significant amount of residues that do not reach the landing during the harvesting process that could potentially increase the supply of forest biomass from each harvest unit. The proportion of recoverable residues depends on their collection costs which are a function of the distance from roadside landing, terrain conditions, and collection method as well as subsequent truck transportation costs. Residues close to landings and nearest to the processing center will usually have the lowest delivered costs. Tradeoffs between increasing truck transportation costs and increasing collection costs affect which residues will be collected to reach a supply target or residue payment price. A forest residue collection model using forwarders and excavator loaders is presented to estimate the potential cost of biomass extraction from the forest to roadside landings. Tradeoffs between increasing collection costs and increasing road transportation are examined. The impact of tax credits and site preparation savings are discussed. On flatter terrain, one excavator is efficient at short distances. As distance from landing increases, one excavator loading one forwarder becomes more efficient, and at long distances, one excavator loading two forwarders becomes more efficient. Video available at https://www.youtube.com/watch?v=i5xOUmmdtC4

Are double trailers cost effective for transporting forest biomass on steep terrain?

Transportation of forest biomass on steep terrain involves logistical challenges. Trucks with large single trailers are often unable to travel on forest roads due to their narrowness, tight curves, adverse grades and limited areas to turn around. A shorter trailer must be used but then transportation capacity is limited by the trailer volume due to the low bulk density of the processed biomass, particularly when the biomass is dry. With double trailers, transportation capacity can be limited by allowable legal weight based on axle number and spacing. We developed a simulation model that explores the economic feasibility of using double-trailer configurations to transport forest biomass to a bioenergy facility from the grinder at a landing or from a centralized yard in Washington, Oregon and California. Results show that double trailers can be a cost effective alternative to single trailers under limited conditions in Oregon and Washington, but they are not a competitive option in California due to the state's transportation regulations.Material published in California Agriculture, excluding photographs, is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International license (CC BY-NC-ND 4.0) (http://creativecommons.org/licenses/by-nc-nd/4.0/#). Material may be copied and redistributed freely under the following terms: • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. • NonCommercial — You may not use the material for commercial purposes. • NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material. • No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits. When attributing, please credit California Agriculture, University of California, citing volume and number, or complete date of issue, followed by page numbers. Indicate ©2015 The Regents of the University of California.Keywords: Bioenergy, forest economics, Transportatio

Economic implications of grinding, transporting and pretreating fresh versus aged forest residues for biofuel production

The moisture content in forest harvest residues is a key factor affecting the supply cost for bioenergy production. Fresh harvest residues tend to contain higher amounts of water thus making transportation inefficient. Additionally, fresh harvest residues contain greater amounts of needles and bark that may reduce the content of polysaccharides, thus, affecting the production of liquid fuels derived from cellulosic components. In this study, we estimated the downstream economic effect in the supply chain of collecting, grinding, transporting and pretreating fresh versus aged residues. Specifically, we analyzed the effect of feedstock moisture content on grinder fuel consumption, bulk density, needles and bark content and polysaccharides proportion. Fresh forest harvest residues were 60% moisture content (wet basis) and aged forest residues were 15% moisture content. The bark and needles proportion is 6.1% higher in fresh versus aged residue. Polysaccharides were 26% higher in aged residue as compared to fresh residue. On a dry tonne basis, the cost of grinding fresh residues was about the same as aged residues. However, considering the difference in bulk density on transportation cost and the difference in polysaccharides yield, the value gain for in-field drying range from USD 29.6 to 74.9 per oven-dry tonne.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Stochastic simulation and optimization of mobile chipping economics in processing and transport of forest biomass from residues

We analyzed the economics of mobile chipping and transport of biomass from forest residues for energy purposes under uncertainty. A discrete-event simulation model was developed and utilized to quantify the impacts of controllable and environmental variables on productivity in order to determine the most cost effective transportation options under steep terrain conditions. Truck-chipper interactions were analyzed to show their effect on truck and chipper standing time. A costing model was developed to account for operating and standing time cost (for the chipper and trucks). The model used information from time studies of each activity in the productive cycle and spatial-temporal information obtained from geographic information system (GIS) devices, and tracking analysis of machine and truck movements. The model was validated in field operations, and proved to be accurate in providing the expected productivity. A cost distribution was elaborated to support operational decisions of forest managers, landowners and risk-averse contractors. Different scenarios were developed to illustrate the economic effects due to changes in road characteristics such as in-highway transport distance, in-forest internal road distance and pile to trailer chipper traveling distances

Feedstock Logistics

This report is a series of five reports that cover the varied challenges and opportunities related to processing and transporting forest biomass to a biorefinery. Topics covered in this collection include 1) biomass recovery coefficients for OR, WA, ID, MT; 2) moisture management strategies and models; 3) collection and transport models for regional modeling; 4) chipping and grinding production to meet alternative feedstock specifications; and 5) new trailer designs to improve transport efficiency