Amount and availability of forest biomass as an energy resource in a mountainous region in Japan: a GIS-based analysis

Feasibility of energy utilization of forest biomass in a mountainous region in Japan has been discussed with the aid of a geographic information system (GIS). In this study, logging residues, thinned trees, and broad-leaved forests are defined as forest biomass. First, the distribution map of biomass resources has been completed by use of the GIS, and information on topography of each sub-compartment has been prepared. Second, harvesting and transporting systems have been classified into six types according to the parts of tree used as energy source (two types) and topographical conditions (three types). The equations for calculating the costs whose variables are slope, skidding/yarding distance, and transporting distance have been developed. Finally, the relationship has been analyzed between the mass and procurement cost of forest biomass in the region. As a result, logging residues [the annual available amount is 4,035 t/y1 (DM2)] proved to be the most cost effective, followed by broad-leaved forests [0,317 t/y (DM)]; thinned trees [27,854 t/y (DM)] proved to be the most costly. This analysis could be of help in drawing an operational plan, i.e., in selecting sub-compartments to be felled. For instance, it has been calculated that the amount of biomass resources of 30,106 t/y (DM) was required for the construction of a power-generation plant that covered 24.8%of the power consumed by households in the region. To obtain this amount of forest biomass for energy purposes, forest biomass should be harvested in sub-compartments, whose procurement costs are lower than 13,037 yen/t (DM)

Current Situation and Future Outlook of Forest Biomass Production and Its Utilization in Japan

The current situation of forests and forestry as well as woody biomass utilization in Japan was described, and the future outlook for the use of forest biomass in Japan was presented. Many planted forests are now becoming mature, so the operational efficiency in forestry should be improved not only by the development of the forest infrastructure but also by the full mechanization of the logging system. The Kyoto Protocol adopted in 1997 promoted the energy utilization of waste woody biomass such as mill residues and wood-based waste materials, and the launch of the Feed-in Tariff scheme for renewable energy (FIT) in 2012 promoted the energy utilization of once-unutilized thinnings. In order to further expand the production of forest biomass and its utilization for energy, logging residues, small-sized trees, and short rotation woody coppices (SRWC) are promising. Thus, low-cost harvesting technologies should be developed as soon as possible, with reference to machines and systems operating in foreign countries where the utilization of such forest biomass is making steady progress

Estimating Annual Available Amounts of Forest Biomass Resources with Total Revenues and Costs during the 60-Year Rotation in a Mountainous Region in Japan

This study extracted production forests and estimated the annual available amounts of forest biomass resources under profitable forest management. Production forests were extracted as sub-compartments where expected revenues surpassed all costs, from planting to final harvesting, for a 60-year rotation. These revenues and costs were estimated for two types of timber harvesting systems (a conventional operation system using a chainsaw and mini-forwarder, and a mechanized operation system using a processor and forwarder) and three types of forest biomass harvesting systems (normal extraction, landing sales, and no biomass extraction) in each sub-compartment using a geographic information system. Then, annual available amounts of forest biomass resources were estimated on the basis of annual supply potentials from production forests. The model was then applied to Nasushiobara City and the Kanuma area in Tochigi Prefecture, Japan. As a result, the number of profitable sub-compartments was estimated as 2,814 out of a total of 5,756 in Nasushiobara City, and 22,872 out of a total of 32,851 in the Kanuma area. The annual amounts of available forest biomass resources were estimated as 11,849 m3 y–1 and 115,213 m3 y–1 in Nasushiobara City and the Kanuma area, respectively. These amounts largely exceed the annual demands of a 500 kW woody biomass power generation plant planned in Nasushiobara City (6,000 m3 y–1) and a chip production factory located in the Kanuma area (12,000 m3 y–1), respectively. €1 = 143 yen on March 13, 201

Forest biomass diversion in the Sierra Nevada: Energy, economics and emissions

As an alternative to open pile burning, use of forest wastes from fuel hazard reduction projects at Blodgett Forest Research Station for electricity production was shown to produce energy and emission benefits: energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); based on measurements from a large pile burn, air emissions reductions were 98%-99% for PM2.5, CO (carbon monoxide), NMOC (nonmethane organic compounds), CH4 (methane) and BC (black carbon), and 20% for NOx and CO2-equivalent greenhouse gases. Due to transport challenges and delays, delivered cost was $70 per bone dry ton (BDT) - comprised of collection and processing ($34/BDT) and transport ($36/BDT) for 79 miles one way - which exceeded the biomass plant gate price of$45/BDT. Under typical conditions, the break-even haul distance would be approximately 30 miles one way, with a collection and processing cost of $30/BDT and a transport cost of$16/BDT. Revenue generated from monetization of the reductions in air emissions has the potential to make forest fuel reduction projects more economically viable

Application of a Sugarcane Harvester for Harvesting of Willow Trees Aimed at Short Rotation Forestry: an Experimental Case Study in Japan

An experiment on the growing and harvesting of willow trees aimed at short rotation forestry was conducted in northern Japan. Willows were harvested using a sugarcane harvester from southern Japan during its agricultural off-season. The growing experiment showed the high potential of willow plantations to produce woody biomass of more than 10 dry-t/ha/y. The harvesting experiment showed that space for turning around, one line in one row as a planting method, a growing cycle of three years, and an extractor fan in the harvester are necessary for mechanical harvesting. Mechanical harvesting was considered to have little influence on willow regeneration provided that the machine cut reasonably well-grown trees. The system performance of harvesting and collecting willow billets in a hypothetical model field was calculated as 22.4 m^3/h, suggesting the feasibility of supplying low-cost wood chips

Discussion on Economic and Energy Balances of Forest Biomass Utilization for Small-Scale Power Generation in Kanuma, Tochigi Prefecture, Japan

In this study, the economic and energy balances of forest biomass utilization for small-scale power generation are discussed, considering the spatial distribution of the forest biomass resources using the geographic information system (GIS) in the Kanuma area of Tochigi Prefecture, Japan. First, the optimum scales of two power-generation plants are discussed. For a direct combustion power-generation plant operating at an optimum scale of 5MWgeneration capacity, the electricity cost would be 23.7 yen/kWh. For a small-scale gasification power plant operating at an optimal scale of 2.4MWgeneration capacity, the electricity cost would be 12.8 yen/kWh. As the average electricity price in Japan is 22.2 yen/kWh, the electricity generated from the small-scale gasification power-generation plant could be economical. The energy balance and CO2 emissions from the energy utilization of forest biomass resources were analyzed using the life cycle inventory (LCI) method. For both types of power generation, the ratio of energy output to input was calculated to be about 20, indicating that the system examined in this study could be feasible as an energy production system. The CO2 emission from the direct combustion power generation with a generation capacity of 5MW was 754.9 tCO2/year, while the CO2 emission of the small-scale gasification power plant with a generation capacity of 2.4MWwas 381.9 tCO2/year. However, the reductions in the amount of CO2 emission that would result from replacing fossil fuel were 15,707 tCO2/year and 6,275 tCO2/year, respectively. €1 = 114 yen on June 27, 2011