Time-Dependent Climate Impact and Energy Efficiency of Internationally Traded Non-torrefied and Torrefied Wood Pellets from Logging Residues

Demand for wood pellets as a renewable alternative to fossil fuels has increased in the past decade. However, production and use of wood pellets involves several operations (biomass extraction, chipping, transport, drying, milling, pelleting, combustion) with negative impacts on e.g. the climate. In this study, the energy efficiency and climate impact of production and use of non-torrefied and torrefied wood pellets were analysed and compared. The wood pellets, produced from logging residues extracted from a boreal coniferous forest stand (Norway spruce (Picea abies (L.) H. Karst)) in northern Sweden, were assumed to be exported and finally used in a power plant. Time-dependent life cycle assessment, expressing the climate impact as global temperature change over time, was used to include annual greenhouse gas fluxes of both fossil and biogenic origin. The results showed that carbon stock changes due to extraction of logging residues contributed most of the warming effect on global temperature. Due to greater demand for raw material, a higher warming impact per gigajoule fuel was obtained for torrefied wood pellets than for non-torrefied wood pellets. However, torrefied wood pellets demonstrated a lower climate impact (per GJ electricity) when advantages such as higher electrical energy efficiency and higher co-firing rate were included. A general conclusion from this study is that replacing coal with non-torrefied or torrefied wood pellets made from logging residues can mitigate climate change. The energy output of these systems was about sevenfold the primary energy input.     

Tracking Economic and Environmental Indicators of Exported Wood Pellets to the United Kingdom from the Southern United States: Lessons for Policy?

This study estimates the abatement cost of greenhouse gas (GHG) emissions for a unit of electricity generated in the UK from wood pellets imported from Southern USA. We assumed that only pulpwood obtained from loblolly pine (Pinus taeda) plantations was used for manufacturing exported wood pellets. The use of imported wood pellets for electricity generation could save at least 69.9 % of GHG emissions relative to coal-based electricity in the UK. The average unit production cost of electricity generated from imported wood pellets (US$222.3 MWh^?1) was higher by 30.0 % than the unit production cost of electricity generated from coal (US$171.0 MWh^?1) without any price support. In the presence of payments from the established price support mechanisms of Renewable Obligation Certificates (ROCs) and Levy Exemption Certificates (LECs), the unit production cost of electricity generated from imported wood pellets (US$142.9 MWh^?1) was lower by about 16.0 % than the unit production cost of electricity generated from coal. Policy makers should consider 1 MWh of electricity generated from imported wood pellets equivalent to 0.58 ROCs or 0.71 ROCs in presence and absence of payments from LECs, respectively. This will ensure zero abatement cost and lead to economic efficiency in reducing GHG emissions. However, a more in-depth analysis focusing on the market risks for power-generating companies and other wood pellet supply chains is required before modifying existing equivalency factors for ensuring continuous use of imported wood pellets for displacing coal-based electricity in the UK.     

Is Use of Both Pulpwood and Logging Residues Instead of Only Logging Residues for Bioenergy Development a Viable Carbon Mitigation Strategy?

This study adopts an integrated life-cycle approach to assess overall carbon saving related with the utilization of wood pellets manufactured using pulpwood and logging residues for electricity generation. Carbon sequestered in wood products and wood present in landfills and avoided carbon emissions due to substitution of grid electricity with the electricity generated using wood pellets are considered part of overall carbon savings. Estimated value of overall carbon saving is compared with the overall carbon saving related to the current use of pulpwood and logging residues. The unit of analysis is a hectare of slash pine (Pinus elliottii) plantation in southern USA. All carbon flows are considered starting from forest management to the decay of wood products in landfills. Exponential decay function is used to ascertain carbon sequestered in wood products and wood present in landfills. Non-biogenic carbon emissions due to burning of wood waste at manufacturing facilities, wood pellets at a power plant, and logging residues on forestlands are also considered. Impacts of harvest age and forest management intensity on overall carbon saving are analyzed as well. The use of pulpwood for bioenergy development reduces carbon sequestered in wood products and wood present in landfills (up to 1.6 metric tons/ha) relative to a baseline when pulpwood is used for paper making and logging residues are used for manufacturing wood pellets. Avoided carbon emissions because of displacement of grid electricity from the electricity generated using wood pellets derived from pulpwood fully compensate the loss of carbon sequestered in wood products and wood present in landfills. The use of both pulpwood and logging residues for bioenergy development is beneficial from carbon perspective. Harvest age is more important in determining overall carbon saving than forest management intensity.     

Life cycle assessment of a pyrolysis/gasification plant for hazardous paint waste

Goal, Scope and Background Life Cycle Assessment (LCA) remains an important tool in Dutch waste management policies. In 2002 the new National Waste Management Plan 2002–2012 (NWMP) became effective. It was supported by some 150 LCA studies for more than 20 different waste streams. The LCA results provided a benchmark level for new waste management technologies. Although not new, operational techniques using combined pyrolysis/gasification are still fairly rare in Europe. The goal of this study is to determine the environmental performance of the only full scale pyrolysis/gasification plant in the Netherlands and to compare it with more conventional techniques such as incineration. The results of the study support the process of obtaining environmental permits. Methods In this study we used an impact assessment method based on the guidelines described by the Centre of Environmental Science (CML) of Leiden University. The functional unit is defined as treatment of 1 ton of collected hazardous waste (paint packaging waste). Similar to the NWMP, not only normalized scores are presented but also 7 aggegated scores. All interventions from the foreground process (land use, emissions, final waste) are derived directly from the site with the exception of emissions to soil which were calculated. Interventions are accounted to each of the different waste streams by physical relations. Data from background processes are taken from the IVAM LCA database 4.0 mostly originating from the Swiss ETH96 database and adapted to the Dutch situation. Allocation was avoided by using system enlargement. The study has been peer reviewed by an external expert. Results and Discussion It was possible to determine an environmental performance for the pyrolysis/ gasification of paint packaging waste. The Life Cycle Inventory was mainly hampered by the uncertainty occurred with estimated air emissions. Here several assumptions had to be made because several waste inputs and two waste treatment installations profit from one flue gas cleaning treatment thus making it difficult to allocate the emission values from the flue gasses. Compared to incineration in a rotary kiln, pyrolysis/gasification of hazardous waste showed better scores for most of the considered impact categories. Only for the impact categories biodiversity and life support the incineration option proved favorable due to a lower land use. Several impact categories had significant influence on the conclusions: acidification, global warming potential, human toxicity and terrestrial ecotoxicity. The first three are related to a better energy efficiency for pyrolysis/gasification leading to less fossil energy consumption. Terrestrial ecotoxicity in this case is related to specific emissions of mercury and chromium (III). A sensitivity analysis has been performed as well. It was found that the environmental performance of the gasification technique is sensitive to the energy efficiency that can be reached as well as the choice for the avoided fossil energy source. In this study a conservative choice for diesel oil was made whereas a choice for heavy or light fuel oil would further improve the environmental profile. Conclusions Gasification of hazardous waste has a better environmental performance compared to the traditional incineration in rotary kilns mainly due to the high energy efficiency. As was determined by sensitivity analysis the differences in environmental performance are significant. Improvement options for a better performance are a decrease of process emissions (especially mercury) and a further improvement of the energy balance by decreasing the electricity consumption for shredders and oxygen consumption or making more use of green electricity. Recommendations and Perspectives Although the life cycle inventory was sufficiently complete, still some assumptions had to be made in order to establish sound mass balances on the level of individual components and substances. The data on input of waste and output of emissions and final waste were not compatible. It was recommended that companies put more emphasis on data storage accounted to particular waste streams. This is even more relevant since more companies in the future are expected to include life cycle impacts in their environmental performance.     

Two-stage steam gasification of waste biomass in fluidized bed at low temperature: parametric investigations and performance optimization

Steam gasification of waste biomass has been studied in a two-stage fluidized bed reactor, which has the primary pyrolysis fluidized bed using silica sand as bed material and the secondary reforming fixed bed with catalyst. The main objectives are parametric investigation and performance improvement especially at low temperature of around 600 °C using the wood chip and the pig manure compost as feedstock. Main operating variables studied are pyrolysis temperature, catalytic temperature, steam/biomass-C ratio, space velocity and different catalyst. Reaction temperatures and steam/C ratio have important role on the gasification process. About 60 vol.% H2 (dry and N2 free) and about 2.0 Nm3/kg biomass (dry and ash free basis) can be obtained under good conditions. Compared to Ni/Al2O3, Ni/BCC (Ni-loaded brown coal char) has a better ability and a hopeful prospect for the stability with coking resistance.     

Quantifying GWI of Wood Pellet Production in the Southern United States and Its Subsequent Utilization for Electricity Production in The Netherlands/Florida

This study attempts to determine global warming impact (GWI) of imported wood pellets from the Southern United States for electricity production in The Netherlands. An attempt is also made to determine GWI of utilizing produced wood pellets within the state of Florida for electricity generation instead of exports. A life-cycle approach is adopted to determine overall GWIs of both the cases. Economic objectives of forest landowners are also incorporated to determine biomass (pulpwood and harvesting residues) availability from a hectare of slash pine plantation. The GWI of a unit of electricity produced at a power plant located at Geertruidenberg, The Netherlands and Gainesville, Florida was 296.4 and 177.5 g of carbon dioxide equivalent greenhouse gas, respectively. An overall saving of 72.6% in greenhouse gas emissions was estimated for every kilowatt-hour of electricity generated using imported wood pellets in The Netherlands when compared with coal-based electricity. This value was found to be 82.4% if produced wood pellets are utilized within Florida for electricity generation instead of exports. A need exists to evaluate the potential of other feedstocks for wood pellet production like understory forest biomass. Additionally, macroeconomic and ecological impacts of utilizing forest biomass for wood pellet production needs to be quantified.     

Carbon and life cycle implications of thermal recovery from the organic fractions of municipal waste

Purpose

The aim of this research was to determine the optimum way of recovering energy from the biodegradable fractions of municipal waste. A part-life cycle study was carried out on the following wastes: paper, food waste, garden waste, wood, non-recyclable mixed municipal waste and refuse-derived fuel. The energy recovery processes considered were incineration, gasification, combustion in dedicated plant, anaerobic digestion and combustion in a cement kiln.

Methods

The life cycle assessment (LCA) was carried out using WRATE, an LCA tool designed specifically for waste management studies. Additional information on waste composition, waste collection and the performance of the energy recovery processes was obtained from a number of UK-based sources. The results take account of the energy displaced by the waste to energy processes and also the benefits obtained by the associated recycling of digestates, metals and aggregates as appropriate.

Results and discussion

For all the waste types considered the maximum benefits in terms of climate change and non-renewable resource depletion would be achieved by using the waste in a cement kiln as a substitute fuel for coal. When considering the impacts in terms of human toxicity, aquatic ecotoxicity, acidification and eutrophication, direct combustion with energy recovery was the best option. The results were found to be highly sensitive to the efficiency of the energy recovery process and the conventional fuel displaced by the recovered energy.

Conclusions and recommendations

This study has demonstrated that LCA can be used to determine the benefits and burdens associated with recovering energy from municipal waste fractions. However, the findings were restricted by the lack of reliable data on the performance of waste gasification and anaerobic digestion systems and on the burdens arising from collecting the wastes. It is recommended that further work is carried out to address these data gaps.     

Status and prospects for renewable energy using wood pellets from the southeastern United States

The ongoing debate about costs and benefits of wood‐pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, ‘How is the production of wood pellets in the SE USA affecting forest systems and the ecosystem services they provide?’ To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in the SE USA are a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services. Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically based best management practices in planning and implementing harvest for the export market. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy also increases the value of forest land to landowners, thereby decreasing likelihood of conversion to nonforest uses. Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long‐term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management.     

Effects of gasifying conditions and bed materials on fluidized bed steam gasification of wood biomass

The effect of steam gasification conditions on products properties was investigated in a bubbling fluidized bed reactor, using larch wood as the starting material. For bed material effect, calcined limestone and calcined waste concrete gave high content of H(2) and CO(2), while silica sand provided the high content of CO. At 650 degrees C, calcined limestone proved to be most effective for tar adsorption and showed high ability to adsorb CO(2) in bed. At 750 degrees C it could not capture CO(2) but still gave the highest cold gas efficiency (% LHV) of 79.61%. Steam gasification gave higher amount of gas product and higher H(2)/CO ratio than those obtained with N(2) pyrolysis. The combined use of calcined limestone and calcined waste concrete with equal proportion contributed relatively the same gas composition, gas yield and cold gas efficiency as those of calcined limestone, but showed less attrition, sintering, and agglomeration propensities similar to the use of calcined waste concrete alone.     

Evaluation of waste mushroom logs as a potential biomass resource for the production of bioethanol

In order to investigate the possibility of using waste mushroom logs as a biomass resource for alternative energy production, the chemical and physical characteristics of normal wood and waste mushroom logs were examined. Size reduction of normal wood (145 kW h/tone) required significantly higher energy consumption than waste mushroom logs (70 kW h/tone). The crystallinity value of waste mushroom logs was dramatically lower (33%) than normal wood (49%) after cultivation by Lentinus edodes as spawn. Lignin, an enzymatic hydrolysis inhibitor in sugar production, decreased from 21.07% to 18.78% after inoculation of L. edodes. Total sugar yields obtained by enzyme and acid hydrolysis were higher in waste mushroom logs than in normal wood. After 24h fermentation, 12 g/L ethanol was produced on waste mushroom logs, while normal wood produced 8 g/L ethanol. These results indicate that waste mushroom logs are economically suitable lignocellulosic material for the production of fermentable sugars related to bioethanol production.     

Utilization of recovered wood in cascades versus utilization of primary wood—a comparison with life cycle assessment using system expansion

Purpose

A cascading utilization of resources is encouraged especially by legislative bodies. However, only few consecutive assessments of the environmental impacts of cascading are available. This study provides answers to the following questions for using recovered wood as a secondary resource: (1) Does cascading decrease impacts on the environment compared to the use of primary wood resources? (2) What aspects of the cascading system are decisive for the life cycle assessment (LCA) results?

Methods

We conducted full LCAs for cascading utilization options of waste wood and compared the results to functionally equivalent products from primary wood, thereby focusing on the direct effects cascading has on the environmental impacts of the systems. In order to compare waste wood cascading to the use of primary wood with LCA, a functional equivalence of the systems has to be achieved. We applied a system expansion approach, considering different options for providing the additionally needed energy for the cascading system.

Results and discussion

We found that the cascading systems create fewer environmental impacts than the primary wood systems, if system expansion is based on wood energy. The most noticeable advantages were detected for the impact categories of land transformation and occupation and the demand of primary energy from renewable sources. The results of the sensitivity analyses indicate that the advantage of the cascading system is robust against the majority of considered factors. Efficiency and the method of incineration at the end of life do influence the results.

Conclusions

To maximize the benefits and minimize the associated environmental impacts, cascading proves to be a preferable option of utilizing untreated waste wood.     

Fluidized-bed steam gasification of rice hull

Steam gasification of grain by-products can be a significant biomass conversion technology because of the need to utilize agricultural waste for non-food applications including energy resources. The most obvious beneficiary will be the developing countries whose economies are often tied to agricultural produce and are lacking in conventional fuels. One agricultural by-product that shows promise is the rice hull; it is found in abundance in the rice mills of producer countries and is considered as a waste material. Although gasification of rice hull has been proposed as a potential waste disposal and energy recovery method, little has been done to fully realize this proposition. In the present work, data were obtained for steam gasification of rice hull in a bench-scale fluidized-bed gasifier, a technology which has proven to be feasible for other grain by-products. The produced gas, which is rich in hydrogen, has been found to have a heating value ranging between 12.1 and 11.1 MJ m⁻³ at the respective reactor temperatures of 700 and 800°C; energy recovery varies between 35 and 59%.     

Environmental footprints of British Columbia wood pellets from a simplified life cycle analysis

Purpose  

Environmental footprints of wood pellets produced in British Columbia (BC) of Canada are to be estimated based on industry surveys and published emission factor data.     

Design,Construction, and Operation of a Fast Pyrolysis Plant for Biomass

A continuous fluidized‐bed plant (PDU‐scale) for fast pyrolysis of lingnocellulosic biomass gives rise to bio‐oil yields of 65 wt.‐%. The average reactor gas residence time was 1.2 s only. The gas and charcoal yields were 15–20 wt.‐%, respectively. The bio oils were chemically characterized. The main monomeric products of the thermal degradation of carbohydrates are acetic acid, hydroxyacetaldehyde, hydroxypropanone, and levoglucosan. The process described in this paper can also be used for disposal of inorganic‐, metal‐organic‐, and chlorine‐organic contaminated waste‐wood. Inorganic compounds of wood preservatives are concentrated in the charcoal fraction and can be separated easily. Chlorine‐organic wood preservatives are mostly degraded. The process has been positively tested as a technique for disposal, recycling, and exploitation of industrial biomass waste (wood waste, grinding grit, fibre sludge, cocoa shell and modern composites like HPL). Bio oil from fast pyrolysis can be used for the production of energy and chemical feedstock. Research for these purposes is ongoing.     

Damaged forests provide an opportunity to mitigate climate change

British Columbia (BC) forests are estimated to have become a net carbon source in recent years due to tree death and decay caused primarily by mountain pine beetle (MPB) and related post‐harvest slash burning practices. BC forest biomass has also become a major source of wood pellets, exported primarily for bioenergy to Europe, although the sustainability and net carbon emissions of forest bioenergy in general are the subject of current debate. We simulated the temporal carbon balance of BC wood pellets against different reference scenarios for forests affected by MPB in the interior BC timber harvesting area using the Carbon Budget Model of the Canadian Forest Sector (CBM‐CFS3). We evaluated the carbon dynamics for different insect‐mortality levels, at the stand‐ and landscape level, taking into account carbon storage in the ecosystem, wood products and fossil fuel displacement. Our results indicate that current harvesting practices, in which slash is burnt and only sawdust used for pellet production, require between 20–25 years for beetle‐impacted pine and 37–39 years for spruce‐dominated systems to reach pre‐harvest carbon levels (i.e. break‐even) at the stand‐level. Using pellets made from logging slash to replace coal creates immediate net carbon benefits to the atmosphere of 17–21 tonnes C ha^?1, shortening these break‐even times by 9–20 years and resulting in an instant carbon break‐even level on stands most severely impacted by the beetle. Harvesting pine dominated sites for timber while using slash for bioenergy was also found to be more carbon beneficial than a protection reference scenario on both stand‐ and landscape level. However, harvesting stands exclusively for bioenergy resulted in a net carbon source unless the system contained a high proportion of dead trees (>85%). Systems with higher proportions of living trees provide a greater climate change mitigation if used for long lived wood products.     

Experimental studies on producer gas generation from wood waste in a downdraft biomass gasifier

A process of conversion of solid carbonaceous fuel into combustible gas by partial combustion is known as gasification. The resulting gas, known as producer gas, is more versatile in its use than the original solid biomass. In the present study, a downdraft biomass gasifier is used to carry out the gasification experiments with the waste generated while making furniture in the carpentry section of the institute’s workshop. Dalbergia sisoo, generally known as sesame wood or rose wood is mainly used in the furniture and wastage of the same is used as a biomass material in the present gasification studies. The effects of air flow rate and moisture content on biomass consumption rate and quality of the producer gas generated are studied by performing experiments. The performance of the biomass gasifier system is evaluated in terms of equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate, zone temperatures and cold gas efficiency. Material balance is carried out to examine the reliability of the results generated. The experimental results are compared with those reported in the literature.     

A re-appraisal of wood-fired combustion

Targets for a considerable increase in electricity generation from renewables have been set in order to reduce greenhouse gas emissions and fossil fuel dependence. Extensive planting of willow, poplar and alder as energy crops has been planned for power generation plants which use wood as the fuel. The current trend is to use gasification or pyrolysis technology, but alternatively a case may be made for wood combustion, if wood becomes readily available. A range of wood-fired circulating fluidised bed combustion (CFBC) plants, using from 10 to 10,000 dry tonne equivalent (DTE)/day, was examined using the ECLIPSE process simulation package. Various factors, such as wood moisture content, harvest yield, afforestation level (AL) and discounted cash flow rate (DCF) were investigated to test their influence on the efficiency and the economics of the systems. Steam cycle conditions and wood moisture content were found to have the biggest effects on the system efficiencies; DCF and AL had the largest influences on the economics. Plants which could handle more than 500 dry tonnes/day could be economically viable; those using more than 1000 dry tonnes wood/day could be competitive with large-scale, conventional coal-fired plants, if sufficient wood were available.     

Abatement cost of wood‐based energy products at the production level on afforested and reforested lands

We combined economic and life‐cycle analyses in an integrated framework to ascertain greenhouse gas (GHG) intensities, production costs, and abatement costs of GHG emissions for ethanol and electricity derived from three woody feedstocks (logging residues only, pulpwood only, and pulpwood and logging residues combined) across two forest management choices (intensive and nonintensive) and 31 harvest ages (year 10–year 40 in steps of 1 year) on reforested and afforested lands at the production level for slash pine (Pinus elliottii) in the Southern United States. We assumed that wood chips and wood pellets will be used to produce ethanol and generate electricity, respectively. Production costs and GHG intensities of ethanol and electricity were lowest for logging residues at the optimal rotation age for both forest management choices. Opportunity cost related with the change in rotation age was a significant determinant of the variability in the overall production cost. GHG intensity of feedstocks obtained from afforested land was lower than reforested land. Relative savings in GHG emissions were higher for ethanol than electricity. Abatement cost of GHG emissions for ethanol was lower than electricity, especially when feedstocks were obtained from a plantation whose rotation age was close to the optimal rotation age. A carbon tax of at least $25 and $38 Mg^?1 CO₂e will be needed to promote production of ethanol from wood chips and electricity from wood pellets in the US, respectively.     

Life cycle cost analysis of distributed versus centralized plastic sorting and recycling

Miniaturizing plastic recycling through distributed systems has been viewed as a way to manage waste closer to the source while minimizing logistics requirements. The environmental performance of distributed manufacturing and waste management systems has been evaluated, but few studies have measured the financial performance. This study combines life cycle costing and hybrid simulation modeling to compare the net present value of small-scale distributed versus large-scale centralized systems of sorting and recycling plastic bottles and takeaway containers disposed in Singapore over 7 years. The results showed that distributed systems face a net financial loss at existing prices of SGD80–120/tonne recycled pellets. This is because of the high operation costs, particularly the labor costs due to the reliance on manual sorting. Despite being closer to the waste sources, distributed scenarios have higher fuel costs due to the poorer fuel efficiency of commercial vans compared to the larger trucks in the centralized scenarios. To improve the financial performance of distributed small-scale plastic recycling systems, it is generally recommended that small-scale sorting facilities reduce the reliance on manual labor; the smaller trucks should have higher fuel economies than conventional large waste hauling trucks; the number of small-scale facilities set up should match the amount of waste to be converted; and the price of the recycled pellets should be high enough to recover the high operating costs of recycling. The findings of this study provide motivation for future research in evaluating the financial performance of distributed recycling of other waste streams. This article met the requirements for a gold-gold data badge JIE data openness badge described at http://jie.click/badges      

Ethanol production from acid hydrolysates based on the construction and demolition wood waste using Pichia stipitis

The feasibility of ethanol production from the construction and demolition (C&D) wood waste acid hydrolysates was investigated. The chemical compositions of the classified C&D wood waste were analyzed. Concentrated sulfuric acid hydrolysis was used to obtain the saccharide hydrolysates and the inhibitors in the hydrolysates were also analyzed. The C&D wood waste composed of lumber, plywood, particleboard, and medium density fiberboard (MDF) had polysaccharide (cellulose, xylan, and glucomannan) fractions of 60.7-67.9%. The sugar composition (glucose, xylose, and mannose) of the C&D wood wastes varied according to the type of wood. The additives used in the wood processing did not appear to be released into the saccharide solution under acid hydrolysis. Although some fermentation inhibitors were detected in the hydrolysates, they did not affect the ethanol production by Pichia stipitis. The hexose sugar-based ethanol yield and ethanol yield efficiency were 0.42-0.46 g ethanol/g substrate and 84.7-90.7%, respectively. Therefore, the C&D wood wastes dumped in landfill sites could be used as a raw material feedstock for the production of bioethanol.