Use Of Wood Waste Research Articles

Reduction of PCDD, PCDF and PCB during co-combustion of biomass with waste products from pulp and paper industry

The use of waste wood as an energy carrier has increased during the last decade. However, elevated levels of alkali metals and chlorine in waste wood compared to virgin biomass can cause increased deposit formation and higher concentrations of organic pollutants. In this study, we investigated the effect of the ChlorOut technique on concentrations of organic pollutants. Ammonium sulfate was injected into the combustion system to inhibit formation of KCl (which causes deposits) and persistent organic pollutants, namely polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). The results showed that concentrations of the toxic congeners of PCDD, PCDF and PCB decreased in the presence of ammonium sulfate.

Using Life-Cycle Assessments to Demonstrate the Impact of Using Wood Waste as a Renewable Fuel in Urban Settings for District Heating

ABSTRACT The use of wood waste for heating in urban settings provides an opportunity for communities to reduce annual fossil emissions by directly reducing the amount of fossil fuel used. Life-cycle assessments (LCA) comparing the environmental impacts of alternative processes or products provide the essential information to better understand opportunities for improvement. An LCA was performed on a Seattle, Washington, district heating system that provides thermal energy to a large number of buildings in downtown Seattle. This study presents annual impacts in terms of carbon emissions for heat production generated using a new boiler design fuel mix including wood wastes as well as natural gas. Results are compared with the results from the 100 percent natural gas boiler that was previously used. The LCA includes results from both a life-cycle inventory of all inputs and outputs and a life-cycle impact assessment comparing alternatives. Results show that global warming potential (GWP) was reduced by 57 percent for the mix fuel design boiler compared with an all natural gas boiler. When 100 percent woody biomass is used, the reduction increases to 104 percent. Transportation and collection of feedstocks contributed minimally (8%) to the overall impact, while the combustion life-cycle stage accounted for 92 percent of the total GWP.

Combustion and emission characteristics of a domestic boiler fired with pellets of pine, industrial wood wastes and peach stones

This study evaluates the combustion and emission characteristics of a domestic boiler fired with pellets of pine, industrial wood wastes and peach stones. Initially, the boiler performance, firing pine pellets, was evaluated as a function of the thermal input. Subsequently, the influence of the pellets type on boiler performance was also examined. The results reveal that the type of pellets affects significantly the boiler emissions characteristics, with the pine pellets performing significantly better than the pellets of industrial wood wastes and peach stones. The boiler thermal efficiency is not negatively affected when fired with the pellets of industrial wood wastes and peach stones. Typical operating conditions of the boiler are not suitable for the use of wood wastes and peach stones pellets as CO and HC emissions are superior. The pellets of industrial wood wastes and peach stones have, however, an attractive potential for use in domestic boilers, through the optimization of the boiler operating conditions, being this a sustainable means of energetic valorisation of residues with no specific use.

A standardized well-to-wheel model for the assessment of bioethanol and hydrogen from cellulosic biomass

The well-to-wheel (WtW) results of biomass-based chains are found to be significantly sensitive to changes in the elements of the chain model such as the land use change. Our new standardization model is based on the conviction that the synthesis of a statistical aggregate of the possibilities that are defined by the major models in the field including GREET and GEMIS would build reliability into the result by buffering against the changes in the elements of the chain model. In this paper we assess a chosen set of biomass-based chains in terms of energy and GHG emissions using the innovative concept of the standardization transport model (STM). Hydrogen was found to be very attractive with the use of waste wood. On the other hand, sugar ethanol was found to be a promising fuel for the reduction of GHG emissions. Unfavorable land use changes and high fertilizers use should be avoided to maximize confidence in significant reductions from sugar ethanol.

Assessing Options for Electricity Generation from Biomass on a Life Cycle Basis: Environmental and Economic Evaluation

Co-firing biomass with coal is being increasingly seen in the EU region as an option that could contribute not only towards reaching the Kyoto targets on greenhouse gas emissions but also towards compliance with the EU directives on renewable energy and large combustion plants. Perennial grasses, short rotation coppice, seasonal agricultural residues and waste forestry wood are all considered as viable alternatives. However, although the use of biomass for electricity generation could help reduce direct emissions of pollutants generated during combustion of coal, including carbon dioxide, sulphur dioxide and nitrogen oxides, the whole life cycle implications of using biomass are less clear. This paper uses a life cycle approach to evaluate the environmental impacts and economic costs of co-firing with coal three types of biomass: miscanthus, willow and waste forest wood. Both direct combustion and gasification of biomass are considered. The results of life cycle assessment indicate that all biomass options lead to a substantial reduction in the environmental impacts compared to the coal-only power generation. Overall, use of waste wood appears to be environmentally the most sustainable option. In comparison to direct combustion, biomass gasification has higher global warming potential due to the higher consumption of biomass and energy for gasification. The results of the life cycle economic costing show that electricity from biomass is economically less attractive than from coal. Direct firing is two times more expensive than coal and gasification up to three times. Therefore, while attractive from the environmental point of view, biomass appears currently to be less sustainable economically.

Role of wood waste as source of biomass fuel in the UK

<title/>Biomass is a generic term for a wide range of organic materials, including wood, which is used to generate electricity and/or heat. Waste wood is just one form of biomass for which there is rapidly growing interest in the UK. An overview is provided of the issues involved in the generation, processing and use of wood waste as biomass.

Forest soil rehabilitation with tillage and wood waste enhances seedling establishment but not height after 8 years

We evaluated soil conditions of rehabilitated log landings in the Interior Douglas-fir biogeoclimatic zone of British Columbia during the first 3 years after treatment and the growth of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) on these log landings over 8 years. Rehabilitation treatments included combinations of tillage and the addition of either stockpiled topsoil or one of three organic amendments: hog fuel, sort-yard waste, and a wood waste – biosolids compost. The woody amendments were either applied as a surface mulch or incorporated into the soil after tillage. Tillage and addition of wood waste reduced soil bulk density and increased carbon content. Daytime soil temperatures in summer were lower under a hog fuel mulch than for the other treatments. The plots receiving hog fuel also had higher soil moisture content. One year after treatment, soil mechanical resistance for untreated soils, and those that were simply tilled, exceeded 2500 kPa for much of the growing season. Plots receiving wood waste had lower mechanical resistance. Use of wood waste in rehabilitation improved soil conditions and contributed to improved survival rates for planted lodgepole pine seedlings. Height growth after 8 years was not significantly affected by the treatments.

Potential of Wood Waste Ash as an Additive in Concrete

The enormous amount of wastes produced during wood processing operations in many countries provides challenging opportunities for the use of wood waste as a construction material. In this research, wood waste (sawdust and wood shaving) ash (WWA) of pretreated timber of 0, 5, 10, 15, 20, 25, and 30% by weight of cement was added as a supplement to a concrete of mix proportion 1:2:4:0.56 (cement:sand:coarse aggregate:water cement ratio), and the strengths and the water absorption of the matrix were evaluated. Also, the metal leachability of WWA was analyzed. The compressive and the flexural strengths of WWA concrete for the ages investigated ranged from 12.83to28.66N∕mm2, and 3.65to5.57N∕mm2, respectively, with the lowest values obtained at 30% additive level of ash. When compared with the strength of plain concrete (control), the compressive and flexural strengths of WWA concrete were between 62 and 91% and 65 and 98%, respectively, of the former. The trend of the water absorption of WWA concrete was a reversal of those of the strengths, that is, the highest water absorption values were recorded for concrete specimens with the highest additive level of ash. A batch leaching test also performed at an ash-leachant volumetric ratio of 20 produced leachate containing chromium, arsenic, iron, copper, and zinc at the following concentrations: 410, 6720, 150, 280, and 1690μg∕L, respectively, when leached at a pH of 4, and 400, 10,670, 0, 100, 1470μg∕L, respectively, when leached at a pH of 5. These concentration levels exceed the EPA fresh water acute criteria limits.

Effectiveness of policy instruments for supporting the use of waste wood as a renewable energy resource in the Czech Republic

This paper focuses on an examination of the government's strategy for encouraging the use of wood as a renewable fuel in Czech households. It examines the development of modern combustion technology and its impact on the environment. It describes the estimated requirement for wood by an average household and examines the overall availability of wood as a renewable fuel in the Czech Republic. The paper analyses in detail the policy instruments used by the Czech government to promote the use of this technology. It evaluates the impact of this policy on the users of the technology and practical achievements of the policy measures with respect to the overall objective that is the promotion of generation of renewable energy.

Life Cycle Inventory of Particleboard: A Case Study in the Wood Sector (8 pp)

Wood has many applications and it is often in competition with other materials. Chipboard is the most common item of wood-based materials and it has attained the highest economical development in recent years. Relevant up-to-date environmental data are needed to allow the environmental comparison of wood with other materials. There are several examples of Life Cycle Assessment (LCA) evaluations of some wood products and forest-technology systems, but no comprehensive Life Cycle Inventory (LCI) data for particleboard manufacture is available in the literature. The main focus of this study is to generate a comprehensive LCI database for the manufacture of resin-bonded wood particleboards. In this work, International Organization for Standardization (ISO) standards and Ecoindicator 99 methodology were considered to quantify the potential environmental impact associated to the system under study. A Spanish factory considered representative of the 'state of art' was studied in detail. The system boundaries included all the activities taking place inside the factory as well as the activities associated with the production of the main chemicals used in the process, energy inputs and transport. All the data related to the inputs and outputs of the process were obtained by on-site measurements. LCI methodology was used for the quantification of the impacts of the particleboard manufacture. The inventory data of the three defined subsystems are described: - Wood preparation: a comprehensive inventory of data including storage, debarking, particle production, storage and measurement of particles, drying and combustion of the bark for energy purposes. - Board shaping: data related to particle classification, resin mixing, mattress formation and the pressing stage. - Board finishing: cooling data, finishing, storage and distribution of the final product. The system was characterised with Ecoindicator 99 methodology (hierarchic version) in order to identify the 'hot spots'. Damage to Human Health was mainly produced by the subsystem of Board finishing. The subsystem of Board shaping was the most significant contributor to damage to the Ecosystem Quality and Resources. With the final aim of creating a database to identify and characterise the manufacture of particleboard, special attention was paid to the inventory analysis stage of the particleboard industry. A multicriteria approach was applied in order to define the most adequate use of wood wastes. Environmental, economic and social considerations strengthen the hypothesis that the use of forest residues in particleboard manufacture is more sustainable than their use as fuel. In this work, particleboard was the product analysed, as it is one of the most common wood-based materials. Future work will focus on the study of another key wood board: Medium Density Fibreboard (MDF). Moreover, factors with strong geographical dependence, such as the electricity profile and final transport of the product, will be analysed. In addition, the definition of widespread functional unit to study the use of wood wastes at the end-of-life stage may be another issue of outstanding interest.

The German bakery waste incident; use of a combined approach of screening and confirmation for dioxins in feed and food

During the last six years several incidents have occurred with dioxins in feed, stressing the need for rapid screening methods for these compounds. The most recent incident was the contamination of bakery waste used for animal feed due to the use of waste wood for drying of the material. In addition to Germany, the material was also shipped to the Netherlands. Levels up to 12 ng TEQ/kg have been detected, being about 15 times over the current limit of 0.75 ng TEQ/kg. In the Netherlands a combined strategy of screening with the CALUX-bioassay and the HRGC/HRMS confirmatory method was used to rapidly control the incident. Pigs were contaminated by the incident but only to a very limited extent. Despite the rather low limits for pig meat, the CALUX bioassay showed excellent performance, once again confirming the value of this assay.

Use of Wood Waste in Rehabilitation of Landings Constructed on Fine-Textured Soils, Central Interior British Columbia, Canada

Abstract Rehabilitation of temporary landings and roads constructed on fine-textured Alfisols must ameliorate poor soil structure, high bulk densities, and greatly reduced organic matter. A long-term field experiment in the central interior of British Columbia (BC) was begun in 1995 to compare soil properties and seedling growth on landings rehabilitated with three operationally feasible treatments: (1) incorporation of waste wood chips (140 t/ha, oven-dry basis), supplemented with 600 kg N/ha; (2) subsoiling; and (3) shallow tillage combined with recovery and spreading of topsoil. After 4 years, soil bulk density at 7–14 cm depth was lowest in the chip incorporation treatment. Although total C, N, and S, and mineralizable N concentrations were highest in the topsoil recovery treatment, the chip incorporation treatment had the highest 3-year growth rates of hybrid white spruce (Picea glauca × engelmannii). Foliar analyses indicated that macro- and micronutrient concentrations were generally adequate, with only S and Mg being of concern. Establishment of paper birch (Betula papyrifera) did not succeed due to severe rodent damage to seedlings, perhaps encouraged by rapid and dense revegetation by seeded agronomic legumes. Silviculturists should consider treatments involving incorporation of chipped wood wastes, with appropriate supplementary N fertilization, in rehabilitation of access structures on fine-textured soils in the BC central interior. West. J. Appl. For. 19(3):175–183.

Evaluation of the environmental impact of waste wood co-utilisation for energy production

The need for a practical, economic and environmentally sound solution for waste wood arises from the requirements for resource conservation and recent regulations. Co-firing with coal is a promising option for the thermal recycling of waste wood. The overall environmental impact caused by the co-utilisation of waste wood with coal was evaluated by using life cycle assessment as established by Society of Environmental Toxicology and Chemistry (SETAC) [A technical framework for life cycle assessment. Washington, DC: SETAC, USA; 1991, Guidelines for life cycle assessments: A code of practice. Brussels: SETAC, Europe; 1993]. This provides opportunities to evaluate direct environmental impact, to identify possible improvements, and to reduce energy resource consumption. In this work, the environmental impact of co-utilising lignite and waste wood in an industrial steam boiler was evaluated. Results obtained showed that co-utilisation is technically feasible and can meet strict environmental standards. A net decrease of CO 2 emissions can be achieved by the thermal use of waste wood, as well as conservation of fossil fuel resources, minimisation of waste disposal and reduction of impacts on health.