Energy and climate impact assessment of waste wood recovery in Switzerland

Today, about 1,800,000 m3 of waste wood are generated on the Swiss territory. With the decision of the Federal Council to phase out nuclear energy in the medium term, new energy source need to be found to compensate the shortfall of electricity production without compromising the GHG emission reductions targets. The aim objective is to assess the long term waste wood potentials for the energy generation and climate change mitigation in Switzerland in the span of a century. The evaluation method relied on a modelling by material flux analysis (MFA) of the metabolism of wood and waste wood in the Swiss anthroposphere. The results reveal that waste wood will stays a limited energy source for the electricity generation but a significant secondary feedstock to meet the energy generation targets from the bioenergy. The heat production from waste wood has the potential to become a significant energy source to answer to the heating district demand. Thus, the relevance of the energy recovery of waste wood lies in its ability to substitute the fossil energy sources for heat demand.

Assessment of the coherence of the Swiss waste wood management

Analysis of the global warming potential for wood waste recycling systems

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

The State of Wisconsin has been a leader in recycling and waste reduction for a number of years. With the passage of 1990 Recycling and Waste Reduction Act 335, the State banned over 15 items from landfill disposal and created a series of financial mechanisms to further waste reduction efforts. Since the Act's passage, the State has provided over $300 million in grants and loans to municipalities and businesses and achieved a 40% reduction from landfill disposal. However, despite this significant effort, many materials are still being landfilled. Based upon these results, more recent attempts have been made to address problem materials. The UW-Extension, in cooperation with staff and students from the Milwaukee School of Engineering, has targeted several key materials for waste reduction efforts. These include: (1) Electronic equipment, especially TVs and computers; (2) wood wastes and (3) mercury containing materials. These studies have indicated that further reduction of these materials will lead to significant reductions of green house gas emissions, decrease the toxicity of waste disposal, and lead to less reliance on landfill disposal. This paper will highlight these research findings as well as the strategies being proposed and implemented to achieve further reductions in Wisconsin's municipal solid waste.

Potential for greenhouse gas reduction and energy recovery from MSW through different waste management technologies

The use of biochar to stabilize soil contaminants is emerging as a technique for remediation of contaminated soils. In this study, an environmental assessment of systems where biochar produced from wood waste with energy recovery is used for remediation of soils contaminated with polycyclic aromatic hydrocarbons (PAH) and metal(loid)s was performed. Two soil remediation options with biochar (on- and off-site) are considered and compared to landfilling. The assessment combined material and energy flow analysis (MEFA), life cycle assessment (LCA), and substance flow analysis (SFA). The MEFA indicated that on-site remediation can save fuel and backfill material compared to off-site remediation and landfilling. However, the net energy production by pyrolysis of wood waste for biochar production is 38% lower than incineration. The LCA showed that both on-site and off-site remediation with biochar performed better than landfilling in 10 of the 12 environmental impact categories, with on-site remediation performing best. Remediation with biochar provided substantial reductions in climate change impact in the studied context, owing to biochar carbon sequestration being up to 4.5 times larger than direct greenhouse gas emissions from the systems. The two biochar systems showed increased impacts only in ionizing radiation and fossils because of increased electricity consumption for biochar production. They also resulted in increased biomass demand to maintain energy production. The SFA indicated that leaching of PAH from the remediated soil was lower than from landfilled soil. For metal(loid)s, no straightforward conclusion could be made, as biochar had different effects on their leaching and for some elements the results were sensitive to water infiltration assumptions. Hence, the reuse of biocharremediated soils requires further evaluation, with site-specific information. Overall, in Sweden's current context, the biochar remediation technique is an environmentally promising alternative to landfilling worth investigating further.

Waste wood as bioenergy feedstock. Climate change impacts and related emission uncertainties from waste wood based energy systems in the UK

Comparative study on the life-cycle greenhouse gas emissions of the utilization of potential low carbon fuels for the cement industry

The disposal of wood waste at facilities for incineration in Sweden is the only applied management practice today. Energy production from biomass has gained attention for its potential to recover energy and reduce greenhouse gas emissions. However, besides being a valuable source for energy generation, wood waste can be effectively recycled into new products. Specifically, recycling wood waste into particleboard is the widely practiced method in Europe, while its benefits have not been explored in the country so far. The objective of this study is to assess the environmental, social, and economic sustainability of producing particleboard and generating energy from wood waste in Sweden. This research investigates four alternative systems for wood waste disposal. The first system involves the production of heat, the second system involves heat and power by wood waste, while the third and the fourth systems, in addition to energy recovery, include partial recycling of wood waste in particleboard production. A life cycle sustainability assessment covering all three pillars (environment, social, and economic) of sustainability was conducted to compare these systems. The results show that adding recycling schemes to incineration in wood waste management practices strengthens the sustainability for all three aspects, and hence, these management methods can be considered as complementary methods rather than competing methods. When all sustainability categories are considered, alternative three (heat recovery and recycling) comes forward as the best option in 11 out of 16 impact categories.

Effectively addressing today’s energy challenges requires advanced technologies along with policies that influence economic markets while advancing the public good.

Wood is a renewable material that can store biogenic carbon, and waste wood can be recycled to recover bioenergy. The amount of energy recovery from the waste wood can vary depending on the type of wood and its chemical and structural properties. This paper will analyse the life cycle environmental impact of energy recovery from waste wood, starting from the wood production stage. These are cradle-to-cradle systems, excluding the use phase and the waste collection phase. The types of waste wood considered in the current study are softwood, hardwood, medium-density fibreboard (MDF), plywood, and particleboard. The results showed that all waste wood has great potential to produce energy while reducing climate change impact. Hardwood and softwood products showed the most beneficial aspects in terms of energy recovery from waste wood and thus could help to reduce harmful environmental emissions. However, MDF and particleboard show the least potential for energy recovery as they contribute to the greatest emissions among all types of wood products. The outcomes of this study could be used as guiding principles for Australia to consider waste-to-energy recovery facility establishment to generate additional energy while reducing waste wood.

The greenhouse gas (GHG) emissions related to the recycling of wood waste have been assessed with the purpose to provide useful data that can be used in accounting of greenhouse gas emissions. Here we present data related to the activities in a material recovery facility (MRF) where wood waste is shredded and foreign objects are removed in order to produce wood chips for use in the production of particleboard. The data are presented in accordance with the UOD (upstream, operational, downstream) framework presented in Gentil et al. (Waste Management & Research, 27, 2009). The GHG accounting shows that the emissions related to upstream activities (5 to 41 kg CO(2)-equivalents tonne( -1) wood waste) and to activities at the MRF (approximately 5 kg CO(2)-equivalents tonne(-1) wood waste) are negligible compared to the downstream processing (-560 to -120 kg CO(2)equivalents tonne(-1) wood waste). The magnitude of the savings in GHG emissions downstream are mainly related to savings in energy consumption for drying of fresh wood for particleboard production. However, the GHG account highly depends on the choices made in the modelling of the downstream system. The inclusion of saved electricity from avoided chipping of virgin wood does not change the results radically (-665 to -125 kg CO(2)-equivalents tonne(- 1) wood waste). However, if in addition it is assumed that the GHG emissions from combustion of wood has no global warming potential (GWP) and that the energy produced from excess wood due to recycling substitutes energy from fossil fuels, here assumed to be coal, potentially large downstream GHG emissions savings can be achieved by recycling of waste wood (-1.9 to -1.3 tonnes CO(2)-equivalents tonne(- 1) wood waste). As the data ranges are broad, it is necessary to carefully evaluate the feasibility of the data in the specific system which the GHG accounting is to be applied to.

The use of micro-hydropower (MHP) for energy recovery in water distribution networks is becoming increasingly widespread. The incorporation of this technology, which offers low-cost solutions, allows for the reduction of greenhouse gas emissions linked to energy consumption. In this work, the MHP energy recovery potential in Spain from all available wastewater discharges, both municipal and private industrial, was assessed, based on discharge licenses. From a total of 16,778 licenses, less than 1% of the sites presented an MHP potential higher than 2 kW, with a total power potential between 3.31 and 3.54 MW. This total was distributed between industry, fish farms and municipal wastewater treatment plants following the proportion 51–54%, 14–13% and 35–33%, respectively. The total energy production estimated reached 29 GWh∙year−1, from which 80% corresponded to sites with power potential over 15 kW. Energy-related industries, not included in previous investigations, amounted to 45% of the total energy potential for Spain, a finding which could greatly influence MHP potential estimates across the world. The estimated energy production represented a potential CO2 emission savings of around 11 thousand tonnes, with a corresponding reduction between M€ 2.11 and M€ 4.24 in the total energy consumption in the country.

Wood wastes could be renewable resources by recycling as particleboard manufacturing or energy production. Particle board is the most common item of wood waste recycling and energy production from wood wastes has highlighted for energy recovery to reduce greenhouse gas generation in recent years. The aim of this study was to evaluate the environmental benefits of the processes for particle board manufacturing and energy production. The functional unit was one ton of wood wastes and the environmental impact was analyzed by life cycle assessment methodology. The result was that 112kg of carbon dioxide equivalent was produced from particle board manufacturing process and 382kg of carbon dioxide equivalent was produced from combined heat and power generation process. The concept of temporary biomass carbon storage was to applied to this study.