Economic Analysis Of Forest Residues Logistics Options To Produce Quality Feedstocks

"Woody biomass feedstock that is both high-quality and low-cost has become increasingly important for the bioenergy and bioproducts industries. Logging generates forest residues – low-quality feedstock – and4 additional operations that also incur additional cost, such as biomass sorting and treetops processing (BSTP),5 micro-chipping, and screening, are required to improve the feedstock’s quality. Considering recent6 developments in technologies and BSTP to generate high-quality feedstocks, economic models were7 developed in this study to estimate various forest residues logistics operational costs and analyze the8 economics of delivering feedstocks to near-woods Biomass Conversion Technology (BCT) sites or to9 faraway-located power plants in the form of chips, hog-fuel, and bales. The results show that the cost of10 BSTP can vary between 0 and2/Oven Dry Metric Ton (ODMT) based on the biomass sorting intensity.11 The most economical way to deliver forest residues was transporting processed stem-wood from landings12 to near-wood BCT sites and comminuting it into woodchips there [~0/ODMT, assuming a one-way13 (32-km) road-distance and no-cost of BSTP at landings]. Grinding slash at the landing and transporting14 ground-biomass (i.e., hog-fuel) to a plant (

An economic analysis and optimization of forest biomass processing and transportation at the operational level is presented. Renewable sources of energy have captured the interest of public and private institutions to develop cost-effective supply chains to reduce dependence on fossil fuels. The production of energy from forest harvest residues constitutes an opportunity to develop a supply chain for producing heat, electricity and liquid fuels from renewable materials. Special interest has been directed to the production of aviation fuel given the characteristics of the commercial aircraft technology that cannot use other renewable sources such as electricity, nuclear power or wind turbines. In economic terms, the production of energy from forest harvest residues at actual market prices requires efficient cost management and planning in order to compete with traditional fossil fuel supply chains. Efficient cost management requires an understanding of the operational stages in order to propose alternatives to improve the planning process, reduce costs, and increase the chance of success of this emerging supply chain. The main goal of this study is to improve cost-efficiency of an emerging energy supply chain from forest harvest residues. A general objective is the economic optimization of forest biomass processing and transportation at the operational level. We developed a model and frame-work to analyze the economics of forest biomass processing and transportation using mixed integer programming (MIP), simulation, Geographic Information Systems (GIS) and forest operation analysis. We developed an economic costing model that accounts for the cost of machinery and truck waiting time. The study is primarily focused on difficult access steep-land regions although it can also be applied to areas with less restricted road access. A stochastic discrete-event simulation model was developed to estimate cost management strategies to improve economics of mobile chipping operations and analyze the effect of uncertainty in this type of operation. The model was successful in predicting productivity of actual forest biomass recovery operations. The model also allowed analyzing the economic effect of truck-machine interactions when using mobile equipment to process the forest residues With stationary processing equipment, the economic effect of truck-machine interactions on closely coupled operations was analyzed through a simulation model. It was demonstrated that truck-machine interactions affect machine utilization rates and, thus, the economics of the operation. Truck-machine interaction must be accounted for when analyzing forest recovery operations to avoid inaccurate cost estimation. Finally a mathematical solution procedure based on mixed integer programming, GIS and simulation was developed to support planning decisions in forest biomass recovery operations, including economic modeling of the effect of waiting times. The solution procedure was incorporated in the decision support system, Residue Evaluation and Network Optimization (RENO) developed in JAVA platform. The decision support system was demonstrated to be an accurate and effective tool to estimate the most cost effective processing machinery and transport configuration given road access, material physical properties, spatial location of the residue piles and accounting for truck-machine interactions. Additionally, an Ant Colony heuristic is included in the model to bring support to the MIP branch and bound solution method by providing an initial solution for objective function. The model is also flexible to user changes to allow the analyst to analyze the sensitivity of the results to main production variables.

Woody biomass residues generated from timber harvest or fuel reduction thinning operations are a potential feedstock for emerging biomass conversion technologies. However, forest residues typically produce a low quality feedstock which may not be suitable for certain biomass conversion technologies. In an effort to increase feedstock quality, this study separated non-merchantable trees and tops from piled limbs during a timber harvest operation. A portion of the separated material was further processed to remove limbs to create five material types: processed and unprocessed, conifer and hardwood stems, and slash (limbs and chunks). These materials were comminuted with a disc-chipper, grinder, and micro-chipper, two and 12 months after harvest. The quality of the feedstock produced from each machine was characterized by moisture content, particle size distribution, bulk density and ash content. Chapter one reviews the comminution of 2-month old material. There was no difference in moisture content between the chipped materials, however, slash material was significantly lower. Processing material did not have an effect on the size distribution nor bulk density of chips. A lower ash content was observed in the conifer type material after processing. Overall, we learned that through sorting and chipping, we were able to improve feedstock quality compared to ground slash. An improvement in feedstock quality may justify the additional cost to sort. In Chapter two, 12-month old material was comminuted and results were compared to those found in Chapter one. The moisture content of chips collected in the study ranged between 18% and 29%. There was a 7.25% decrease in moisture content across all material types. The size distribution of chip samples were dependent on tree type, moisture content and treatment. The bulk density of the 12-month chips decreased by 12% over the 2-month period due to moisture loss. Results show that additional processing (i.e., delimbing stems) does not have a big impact on ash content, bulk density, nor moisture content. Allowing the material to sit for an additional 10 months did have a significant influence on moisture content, which contributed to changes in particle size and bulk density. The chipper produced 30.1 bone dry metric tonne (BDmT)/productive machine hour (PMH) at an estimated cost of $11.87/BDmT. In Chapter three, 12-month material was comminuted using a micro-chipper designed to produce a 3 mm chip. Micro-chips had a smaller particle size distribution, which raised the bulk density 13% over bulk density results found in Chapter 2. The micro-chipper produced 33.9 BDmT/PMH at an estimated cost of $11.16/BDmT. Our findings show that with proper handling and comminution methods, forest residues, once considered a waste bi-product, have the potential to be a high quality feedstock for biomass conversion technologies. These technologies may provide added value and different options for land managers to handle forest residues.

Results are reported of a preliminary investigation of feasibility of using wood residue to meet energy and raw material needs in the Pacific Coast States. Magnitude of needs was examined and volume of logging-residue and unused mill residue was estimated. Costs of obtaining and preprocessing logging residue for energy and pulp and particle board raw material were estimated and compared with selling values of mill residue fuel, pulp chips, and particle board. Marginally feasible energy use seemed best suited for inplant steam and power production by the wood industry, Although raw material selling values make wood residue use for products more attractive than for electric power generation, even these returns are seldom sufficient to meet the high costs of delivering logging residue for such use alone. Production of higher valued products or public absorption of extra costs of utilization can make these residue management alternatives more feasible.

The TEA and LCA impacts of utilizing low-cost feedstocks in a high-temperature conversion process are of great interest. Here, we investigate the conversion cost impacts of two underutilized feedstocks from the commercial pine industry; 13-year-old whole trees, representing trees removed for the purpose of pre-commercial thinning, and 23-year-old pine residues, representing a waste stream produced from the deconstruction of mature trees for other purposes. Experimental fast pyrolysis data for each feedstock was used in tandem with results from supply and preprocessing analyses in order to evaluate the field-to-fuel economics. A low difference in MFSP was found between the conversion costs for the two feedstocks, with residues demonstrating a net benefit of $0.27/GGE compared to the whole tree thinnings, driven primarily by feedstock supply costs. This suggests that both whole tree thinnings and pine residues may be viable feedstock options for CFP conversion. Life cycle inventories were also generated for each case, enabling a field-to-fuel quantification of the cost and carbon cycle associated with each feedstock.

In the United States, we have come to depend on plentiful and inexpensive energy to support our economy and lifestyles. In recent years, many questions have been raised regarding the sustainability of our current pattern of high consumption of nonrenewable energy and its environmental consequences. Further, because the United States imports about 55 percent of the nation's consumption of crude oil, there are additional concerns about the security of supply. Hence, efforts are being made to find alternatives to our current pathway, including greater energy efficiency and use of energy sources that could lower greenhouse gas (GHG) emissions such as nuclear and renewable sources, including solar, wind, geothermal, and biofuels. The United States has a long history with biofuels and the nation is on a course charted to achieve a substantial increase in biofuels. Renewable Fuel Standard evaluates the economic and environmental consequences of increasing biofuels production as a result of Renewable Fuels Standard, as amended by EISA (RFS2). The report describes biofuels produced in 2010 and those projected to be produced and consumed by 2022, reviews model projections and other estimates of the relative impact on the prices of land, and discusses the potential environmental harm and benefits of biofuels production and the barriers to achieving the RFS2 consumption mandate. Policy makers, investors, leaders in the transportation sector, and others with concerns for the environment, economy, and energy security can rely on the recommendations provided in this report.

Greenhouse Gases Balance of Bioenergy Systems covers every stage of a bioenergy system, from establishment to energy delivery, presenting a comprehensive, multidisciplinary overview of all the relevant issues and environmental risks. It also provides an understanding of how these can be practically managed to deliver sustainable greenhouse gas reductions. Its expert chapter authors present readers to the methods used to determine the greenhouse gas balance of bioenergy systems, the data required and the significance of the results obtained. It also provides in-depth discussion of key issues and uncertainties, such as soil, agriculture, forestry, fuel conversion and emissions formation. Finally, international case studies examine typical GHG reduction levels for different systems and highlight best practices for bioenergy GHG mitigation. For bringing together into one volume information from several different fields that was up until now scattered throughout many different sources, this book is ideal for researchers, graduate students and professionals coming into the bioenergy field, no matter their previous background. It will be particularly useful for bioenergy researchers seeking to calculate greenhouse gas balances for systems they are studying. I will also be an important resource for policy makers and energy analysts. Uses a multidisciplinary approach to synthesize the diverse information that is required to competently execute GHG balances for bioenergy systems Presents an in-depth understanding of the science underpinning key issues and uncertainty in GHG assessments of bioenergy systems Includes case studies that examine ways to maximize the GHG reductions delivered by different bioenergy systems