Bioprocessing of bio-based chemicals produced from lignocellulosic feedstocks

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Life cycle assessment of bread produced on different scales

A case study of white bread has been carried out with the purpose of comparing different scales of production and their potential environmental effects. The scales compared are: home baking, a local bakery and two industrial bakeries with distribution areas of different sizes. Data from the three bakeries and their suppliers have been collected. The systems investigated include agricultural production, milling, baking, packaging, transportation, consumption and waste management. Energy use and emissions have been quantified and the potential contributions to global warming, acidification, eutrophication and photo-oxidant formation have been assessed. The large industrial bakery uses more primary energy and contributes more to global warming, acidification and eutrophication than the other three systems. The home baking system shows a relatively high energy requirement; otherwise, the differences between home baking, the local bakery and the small industrial bakery are too small to be significant.     

Evaluation of sugar feedstocks for bio-based chemicals: A consequential,regionalized life cycle assessment

Fermentable sugars are an attractive feedstock for the production of bio-based chemicals. However, little is known about the environmental performance of sugar feedstocks when demand for sugars increases, and when local conditions and sensitivities of receiving ecosystems are taken into account. Production of monosaccharides from various first- and second-generation feedstocks (sugar beet, sugar cane, wheat, maize, wood, residual woodchips, and sawdust) in different geographic locations was assessed and compared as feedstock for monoethylene glycol (MEG) using consequential, regionalized life cycle assessment. Sugar cane grown in Thailand performed best in all three areas of protection, that is, for life cycle impacts on human health, ecosystem quality, and resources (respectively, equal to −7.6 × 10⁻⁵ disability-adjusted life years, −1.2 × 10⁻⁸ species-years and −0.046 US dollars per amount of feedstock needed to produce 1 kg of MEG). This was mainly due to benefits from by-products—incineration of sugar cane bagasse generating electricity and use of sugar cane molasses for the production of bioethanol. The wood-based feedstocks and maize performed worse than sugar cane and sugar beet, but their evaluation did not consider that sugar extraction technology from lignocellulose is immature, while identification of marginal suppliers of the marginal crop is particularly uncertain for maize. Wheat grown in Russia performed the worst mainly due to low agricultural yields (with impacts equal to 8.9 × 10⁻⁵ disability-adjusted life years, 6.9 × 10⁻⁷ species-years, and 1.8 US dollars per amount of feedstock required to produce 1 kg of bio-based MEG). Our results suggest that selection of sugar feedstocks for bio-based chemicals should focus on (i) the intended use of by-products and functions they replace and (ii) consideration of geographic differences in parameters that influence life cycle inventories, while spatial differentiation in the life cycle impact assessment was less influential.     

Life cycle assessment of fuel ethanol from cassava in Thailand

Goal and Scope  A well-to-wheel analysis has been conducted for cassava-based ethanol (CE) in Thailand. The aim of the analysis is to assess the potentials of CE in the form of gasohol E10 for promoting energy security and reducing environmental impacts in comparison with conventional gasoline (CG). Method  In the LCA procedure, three separate but interrelated components: inventory analysis, characterization and interpretation were performed for the complete chain of the fuel life cycle. To compare gasohol E10 and CG, this study addressed their impact potentials per gasoline-equivalent litre, taking into account the performance difference between gasohol and gasoline in an explosion motor. Results and Discussions  The results obtained show that CE in the form of E10, along its whole life cycle, reduces certain environmental loads compared to CG. The percentage reductions relative to CG are 6.1% for fossil energy use, 6.0% for global warming potential, 6.8% for acidification, and 12.2% for nutrient enrichment. Using biomass in place of fossil fuels for process energy in the manufacture of ethanol leads to improved overall life cycle energy and environmental performance of ethanol blends relative to CG. Conclusions and Outlook  The LCA brings to light the key areas in the ethanol production cycle that researchers and technicians need to work on to maximize ethanol’s contribution to energy security and environmental sustainability ESS-Submission Editor: Mark Goedkoop (goedkoop@pre.nl)     

Life cycle assessment of fuel ethanol from sugarcane in Argentina

Purpose

The production of bioethanol in Argentina is based on the sugarcane plantation system, with extensive use of agricultural land, scarce use of fertilizers, pesticides, and artificial irrigation, and burning of sugarcane prior to harvesting. The objective of this paper is to develop a life cycle assessment (LCA) of the fuel ethanol from sugarcane in Tucumán (Argentina), assessing the environmental impact potentials to identify which of them cause the main impacts.

Methods

Our approach innovatively combined knowledge about the main impact pathways of bioethanol production with LCA which covers the typical emission-related impact categories at the midpoint life cycle impact assessment. Real data from the Argentinean industry subsystems have been used to perform the study: S1—sugarcane production, S2—milling process, S3—sugar production, and S4—ethanol production from molasses, honey, or sugarcane juice.

Results and discussion

The results are shown in the three alternative pathways to produce bioethanol. Different impact categories are assessed, with global warming potential (GWP) having the highest impact. So, the production of 1 kg of ethanol from molasses emitted 22.5 kg CO₂ (pathway 1), 19.2 kg CO₂ from honey (pathway 2), and 15.0 kg CO₂ from sugarcane juice (pathway 3). Several sensitivity analyses to study the variability of the GWP according to the different cases studied have been performed (changing the agricultural yield, including economic and calorific allocation in sugar production, and modifying the sugar price).

Conclusions

Agriculture is the subsystem which shows the highest impact in almost all the categories due to fossil fuel consumption. When an economic and calorific allocation is considered to assess the environmental impact, the value is lower than when mass allocation is used because ethanol is relatively cheaper than sugars and it has higher calorific value.     

Life cycle cost analysis of fuel ethanol produced from cassava in Thailand

Background, aim, and scope

As a net oil importer, Thailand has a special interest in the development of biofuels, especially ethanol. At present, ethanol in the country is mainly a fermentation/distillery product of cane molasses, but cassava holds superior potential for the fuel. This study aims to assess the economics of cassava-based ethanol as an alternative transportation fuel in Thailand. The scope of the study includes the cassava cultivation/processing, the conversion to ethanol, the distribution of the fuel, and all transportation activities taking place within the system boundary.

Materials and methods

The life cycle cost assessment carried out follows three interrelated phases: data inventory, data analysis, and interpretation. The functional unit for the comparison between ethanol and gasoline is the specific distance that a car can travel on 1 L ethanol in the form of E10, a 10% ethanol blend in gasoline.

Results

The results of the analysis show, despite low raw material cost compared to molasses and cane-based ethanol, that cassava ethanol is still more costly than gasoline. This high cost has put an economic barrier to commercial application, leading to different opinions about government support for ethanol in the forms of tax incentives and subsidies.

Discussion

Overall, feedstock cost tends to govern ethanol’s production cost, thus, making itself and its 10% blend in gasoline less competitive than gasoline for the specific conditions considered. However, this situation can also be improved by appropriate measures, as discussed later.

Conclusions

To make ethanol cost-competitive with gasoline, the first possible measure is a combination of increasing crop yield and decreasing farming costs (chemical purchase and application, planting, and land preparation) so as to make a 47% reduction in the cost per tonne of cassava. This is modeled by a sensitivity analysis for the cost in the farming phase. In the industrial phase of the fuel production cycle, utilization of co-products and substitution of rice husk for bunker oil as process energy tend to reduce 62% of the price gap between ethanol and gasoline. The remaining 38% price gap can be eliminated with a 16% cut of raw material (cassava) cost, which is more practical than a 47% where no savings options in ethanol conversion phase are taken into account.

Recommendations and perspectives

The life cycle cost analysis helps identify the key areas in the ethanol production cycle where changes are required to improve cost performance. Including social aspects in an LCC analysis may make the results more favorable for ethanol.     

Life cycle assessment of fuel ethanol from cane molasses in Thailand

Background, aim and scope

After China and India, Thailand is considered another emerging market for fuel ethanol in Asia. At present, ethanol in the country is mainly a fermentation/distillery product of cane molasses, although cassava and cane juice are considered other potential raw materials for the fuel. This study aims to evaluate the environmental impacts of substituting conventional gasoline (CG) with molasses-based gasohol in Thailand.

Materials and methods

The life cycle assessment (LCA) procedure carried out follows three interrelated phases: inventory analysis, characterization and interpretation. The functional unit for the comparison is 1 l gasoline equivalent consumed by a new passenger car to travel a specific distance.

Results

The results of the study show that molasses-based ethanol (MoE) in the form of 10% blend with gasoline (E10), along its whole life cycle, consumes less fossil energy (5.3%), less petroleum (8.1%) and provides a similar impact on acidification compared to CG. The fuel, however, has inferior performance in other categories (e.g. global warming potential, nutrient enrichment and photochemical ozone creation potential) indicated by increased impacts over CG.

Discussion

In most cases, higher impacts from the upstream of molasses-based ethanol tend to govern its net life cycle impacts relative to CG. This makes the fuel blend less environmentally friendly than CG for the specific conditions considered. However, as discussed later, this situation can be improved by appropriate changes in energy carriers.

Conclusions

The LCA procedure helps identify the key areas in the MoE production cycle where changes are required to improve environmental performance. Specifically, they are: (1) use of coal as energy source for ethanol conversion, (2) discharge of distillery spent wash into an anaerobic pond, and (3) open burning of cane trash in sugar cane production.

Recommendations and perspectives

Measures to improve the overall life cycle energy and environmental impacts of MoE are: (1) substituting biomass for fossil fuels in ethanol conversion, (2) capturing CH₄ from distillery spent wash and using it as an energy supply, and (3) utilizing cane trash for energy instead of open burning in fields.     

Life cycle assessment of bio-based products: a disposable diaper case study

Purpose

In this study, a life cycle assessment of a bioplastic based diaper was performed. The product has several innovative elements, due to the implementation of eco-design principles, such as: (1) introduction of biopolymers (namely polylactic acid (PLA) and Mater-bi®), (2) relevant reduction of petrochemical plastics, and (3) minimization of energy consumptions and use of renewable energy in manufacturing. The aim of the study is to evaluate the environmental benefits gained through eco-innovation, while identifying further areas of improvement.

Methods

The bio-based diaper has been evaluated using a “cradle-to-gate” analysis. The functional unit is one diaper, assuming an average size among the different commercial options. A case study of an enterprise in Italy (WIP S.p.A) was carried out to collect as much reliable primary data as possible. In order to highlight potential areas of improvement and to compare the environmental performance of the product, a sensitivity analysis based on three different impact assessment methods (adopting ReCiPe 2008, IMPACT 2002+ and Cumulative Energy Demand (CED)) and a comparison with a standard commercial diaper were performed. Finally, three possible end-of-life scenarios including composting of WIP diaper were hypothesized and tested.

Results and discussion

Contribution analysis suggested that sourcing and production of raw materials used in WIP diaper manufacturing contributed most significantly to the potential environmental impacts. Adopting ReCiPe method, pulp, and sodium polyacrylate present the highest environmental burdens in WIP diaper system. Applying IMPACT2002+ method, PLA relative contribution to the toxicity increases, due to the generation of the electricity used in corn production and in PLA production phases. For both methods, impacts related to energy consumption of the WIP diapers’ production process look to be negligible. WIP diaper performance has room for improvement, since critical points were detected in the life cycle stages of raw materials used. However, the results of the normalization step, according to ReCiPe method, state that WIP diapers can bring environmental benefits, compared to standard ones. Moreover, if composting end-of-life scenario is included in the assessment, there is a significant improvement in WIP diaper environmental performance compared to a standard diaper.

Conclusions

Integrating eco-innovation and eco-design principles in the production of the bio-based diaper leads to a better environmental profile, compared to the standard one. Nevertheless, there are several areas of concerns to be considered in order to further improve its environmental performance. So far, the possible improvements identified from the case study are: (1) the selection of biopolymers suppliers with better production systems from an environmental point of view, (2) the reduction of distances along the supply chain, and (3) the implementation of composting procedures for the end of life. In conclusion, the introduction of biopolymers in diaper composition could lead them to be preferable compared to standard diapers, but criticisms arise, which need to be solved, to avoid the risk of burdens shifting.     

Trends in biotechnological production of fuel ethanol from different feedstocks

Present work deals with the biotechnological production of fuel ethanol from different raw materials. The different technologies for producing fuel ethanol from sucrose-containing feedstocks (mainly sugar cane), starchy materials and lignocellulosic biomass are described along with the major research trends for improving them. The complexity of the biomass processing is recognized through the analysis of the different stages involved in the conversion of lignocellulosic complex into fermentable sugars. The features of fermentation processes for the three groups of studied feedstocks are discussed. Comparative indexes for the three major types of feedstocks for fuel ethanol production are presented. Finally, some concluding considerations on current research and future tendencies in the production of fuel ethanol regarding the pretreatment and biological conversion of the feedstocks are presented.     

Life cycle assessment of switchgrass-derived ethanol as transport fuel

Background, aim, and scope  

The increasing gasoline price, the depletion of fossil resources, and the negative environmental consequences of driving with petroleum fuels have driven the development of alternative transport fuels. Bioethanol, which is converted from cellulosic feedstocks, has attracted increasing attention as one such alternative. This study assesses the environmental impact of using ethanol from switchgrass as transport fuel and compares the results with the ones of gasoline to analyze the potential of developing switchgrass ethanol as an environmentally sustainable transport fuel.     

Life cycle assessment of fuel ethanol derived from corn grain via dry milling

Life cycle analysis enables to investigate environmental performance of fuel ethanol used in an E10 fueled compact passenger vehicle. Ethanol is derived from corn grain via dry milling. This type of analysis is an important component for identifying practices that will help to ensure that a renewable fuel, such as ethanol, may be produced in a sustainable manner. Based on data from eight counties in seven Corn Belt states as corn farming sites, we show ethanol derived from corn grain as E10 fuel would reduce nonrenewable energy and greenhouse gas emissions, but would increase acidification, eutrophication and photochemical smog, compared to using gasoline as liquid fuel. The ethanol fuel systems considered in this study offer economic benefits, namely more money returned to society than the investment for producing ethanol. The environmental performance of ethanol fuel system varies significantly with corn farming sites because of different crop management practices, soil properties, and climatic conditions. The dominant factor determining most environmental impacts considered here (i.e., greenhouse gas emissions, acidification, eutrophication, and photochemical smog formation) is soil related nitrogen losses (e.g., N2O, NOx, and NO3-). The sources of soil nitrogen include nitrogen fertilizer, crop residues, and air deposition. Nitrogen fertilizer is probably the primary source. Simulations using an agro-ecosystem model predict that planting winter cover crops would reduce soil nitrogen losses and increase soil organic carbon levels, thereby greatly improving the environmental performance of the ethanol fuel system.     

Life cycle assessment of printing and writing paper produced in Portugal

Goal, Scope and Background The environmental sustainability is one of the current priorities of the Portuguese pulp and paper industry. Life Cycle Assessment (LCA) was the methodology chosen to evaluate the sustainability of the printing and writing paper production activity. This paper grade represents about 60% of the total production of paper in Portugal and its production is expected to increase in the near future. The main goal of this study was to assess the potential environmental impacts associated with the entire life cycle of the printing and writing paper produced in Portugal from Eucalyptus globulus pulp and consumed in Germany, in order to identify the processes with the largest environmental impacts. Another goal of this study was to evaluate the effect on the potential environmental impacts of changing the market where the Portuguese printing and writing paper is consumed: German market vs. Portuguese market. Methods The main stages considered in this study were: forestry, pulp production, paper production, paper distribution, and paper final disposal. Transports and production of chemicals, fuels and energy in the grid were also included in these stages. Whenever possible and feasible, average or typical data from industry were collected. The remaining data were obtained from the literature and specialised databases. A quantitative impact assessment was performed for five impact categories: global warming over 100 years, acidification, eutrophication, non-renewable resource depletion and photochemical oxidant formation. Results In the German market scenario, the paper production stage was a remarkable hot spot for air emissions (non-renewable CO₂, NO_x and SO₂) and for non-renewable energy consumption, and, consequently, for the impact categories that consider these parameters: global warming, acidification and non-renewable resource depletion. These important environmental impacts are due to the energy requirements in the printing and writing paper production process, which are fulfilled by on-site fuel oil burning and consumption of electricity from the national grid, which is mostly based on the use of fossil fuels. The pulp production stage was identified as the largest contributor to water emissions (COD and AOX) and to eutrophication. Considering that energy consumed by the pulp production processes comes from renewable fuels, this stage was also the most contributing to renewable energy consumption. Discussion The paper distribution stage showed an important contribution to NO_x emissions, which, however, did not result in a major contribution to acidification or eutrophication. The final disposal stage was the main contributor to the photochemical oxidant formation potential due to CH₄ emissions from wastepaper landfilling. On the other hand, paper consumption in Portugal was environmentally more favourable than in Germany for the parameters/impact categories where the paper distribution stage has a significant contribution (non-renewable CO₂, NO_x, non-renewable energy consumption, acidification, eutrophication and non-renewable resource depletion) due to shorter distances needed to deliver paper to the consumers. For the remaining parameters/impact categories, the increase observed in the final disposal stage in the Portuguese market was preponderant, and resulted from the existence of significant differences in the final disposal alternatives in the analysed markets (recycling dominates in Germany, whereas landfilling dominates in Portugal). Conclusions The pulp and paper production stages were found to be of significance for almost all of the inventory parameters as well as for the impact assessment categories. The paper distribution and the final disposal stages were only of importance for some of the inventory parameters and some of the impact categories. The forestry stage played a minor role in the environmental impacts generated during the paper life cycle. The consumption of paper in Portugal led to a decrease in the environmental burdens of the paper distribution stage, but to an increase in the environmental burdens of the final disposal stage, when compared with the consumption of paper in Germany. Recommendations and Perspectives This study provides useful information that can assist the pulp and paper industry in the planning of future investments leading to an increase in its sustainability. The results of inventory analysis and impact assessment show the processes that play an important role in each impact category, which allow the industry to improve its environmental performance, making changes not only in the production process itself, but also in the treatment of flue gases and liquid effluents. Besides that concern regarding pollution prevention, other issues with relevance to the context of sustainability, such as the energy consumption, can also be dealt with.     

玉米秸秆基纤维素乙醇生命周期能耗与温室气体排放分析

生命周期评价是目前分析产品或工艺的环境负荷唯一标准化工具,利用其生命周期分析方法可以有效地研究纤维素乙醇生命周期能耗与温室气体排放问题。为了定量解释以玉米秸秆为原料的纤维素乙醇的节能和温室气体减排潜力,利用生命周期分析方法对以稀酸预处理、酶水解法生产的玉米秸秆基乙醇进行了生命周期能耗与温室气体排放分析,以汽车行驶1 km为功能单位。结果表明：与汽油相比,纤维素乙醇E100 (100％乙醇) 和E10 (乙醇和汽油体积比=1∶9) 生命周期化石能耗分别减少79.63％和6.25％,温室气体排放分别减少53.98％和6.69％;生物质阶段化石能耗占到总化石能耗68.3％,其中氮肥和柴油的生命周期能耗贡献最大,分别占到生物质阶段的45.78％和33.26％;工厂电力生产过程的生命周期温室气体排放最多,占净温室气体排放量的42.06％,提升技术减少排放是降低净排放的有效措施。     

Life cycle assessment for emerging materials: case study of a garden bed constructed from lumber produced with three different copper treatments

Purpose

The objective of this research was to evaluate the appropriateness of using life cycle assessment (LCA) for new applications that incorporate emerging materials and involve site-specific scenarios. Cradle-to-grave impacts of copper-treated lumber used in a raised garden bed are assessed to identify key methodological challenges and recommendations applying LCA for such purposes as well as to improve sustainability within this application.

Methods

The functional unit is a raised garden bed measuring 6.67 board feet (bf) in volume over a period of 20 years. The garden beds are made from softwood lumber such as southern yellow pine. The two treatment options considered were alkaline copper quaternary and micronized copper quaternary. Ecoinvent 2.2 provided certain life cycle inventory (LCI) data needed for the production of each garden bed, while additional primary and secondary sources were accessed to supplement the LCI.

Results and discussion

Primary data were not available for all relevant inventory requirements, as was anticipated, but enough secondary data were gathered to conduct a screening-level LCA on these raised garden bed applications. A notable finding was that elimination of organic solvent could result in a more sustainable lumber treatment product. Conclusions are limited by data availability and key methodological challenges facing LCA and emerging materials.

Conclusions

Although important data and methodological challenges facing LCA and emerging materials exist, this LCA captured material and process changes that were important drivers of environmental impacts. LCA methods need to be amended to reflect the properties of emerging materials that determine their fate, transport, and impacts to the environment and health. It is not necessary that all recommendations come to light before LCA is applied in the context of emerging materials. Applications of such materials involve many inputs beyond emerging materials that are already properly assessed by LCA. Therefore, LCA should be used in its current state to enhance the decision-making context for the sustainable development of these applications.     

Life cycle assessment of sugarcane ethanol production in India in comparison to Brazil

Purpose

India’s biofuel programme relies on ethanol production from sugarcane molasses. However, there is limited insight on environmental impacts across the Indian ethanol production chain. This study closes this gap by assessing the environmental impacts of ethanol production from sugarcane molasses in Uttar Pradesh, India. A comparative analysis with south-central Brazilian sugarcane ethanol is also presented to compare the performance of sugarcane molasses-based ethanol with sugarcane juice-based ethanol.

Methods

The production process is assessed by a cradle-to-gate life cycle assessment. The multifunctionality problem is solved by applying two variants of system expansion and economic allocation. Environmental impacts are assessed with Impact 2002+ and results are presented at the midpoint level for greenhouse gas emissions, non-renewable energy use, freshwater eutrophication and water use. Furthermore, results include impacts on human health and ecosystem quality at the damage level. Sensitivity analysis is also performed on key contributing parameters such as pesticides, stillage treatment and irrigation water use.

Results and discussion

It is found that, compared to Brazilian ethanol, Indian ethanol causes lower or comparable greenhouse gas emissions (0.09–0.64 kgCO_2eq/kg_ethanolIN, 0.46–0.63 kgCO_2eq/kg_ethanolBR), non-renewable energy use (?0.3–6.3 MJ/kg_ethanolIN, 1–4 MJ/kg_ethanolBR), human health impacts (3.6?·?10^?6 DALY/kg_ethanolIN, 4?·?10^?6 DALY/kg_ethanolBR) and ecosystem impairment (2.5 PDF?·?m²?·?year/kg_ethanolIN, 3.3 PDF?·?m²?·?year/kg_ethanolBR). One reason is that Indian ethanol is exclusively produced from molasses, a co-product of sugar production, resulting in allocation of the environmental burden. Additionally, Indian sugar mills and distilleries produce surplus electricity for which they receive credits for displacing grid electricity of relatively high CO₂ emission intensity. When economic allocation is applied, the greenhouse gas emissions for Indian and Brazilian ethanol are comparable. Non-renewable energy use is higher for Indian ethanol, primarily due to energy requirements for irrigation. For water use and related impacts, Indian ethanol scores worse due groundwater irrigation, despite the dampening effect of allocation. The variation on greenhouse gas emissions and non-renewable energy use of Indian mills is much larger for high and low performance than the respective systems in Brazil.

Conclusions

Important measures can be taken across the production chain to improve the environmental performance of Indian ethanol production (e.g. avoiding the use of specific pesticides, avoiding the disposal of untreated stillage, transition to water efficient crops). However, to meet the targets of the Indian ethanol blending programme, displacement effects are likely to occur in countries which export ethanol. To assess such effects, a consequential study needs to be prepared.     

Life cycle assessment standards

The newly emerging LCA standards provide an opportunity to review and improve upon the current LCA methodology. As more industrial practitioners enter the arena, the opportunity arises to not only demand environmental improvement from industrial service and product providers but also to fill LCA data gaps. A framework is suggested for improvement in the current LCA framework that focuses on the business relationships of the industrial practitioner. The framework seeks to promote environmental improvement from industrial sectors through the identification of state-of-the-art technologies used throughout a life cycle. Basing LCAs on the best performers in an industry will create a market for a high level of environmental performance, disperse the responsibility of inventory data gathering, and improve upon the advancements already anticipated through the widespread application of LCA.     

Life cycle assessment of medium density particleboard (MDP) produced in Brazil

Purpose

The wood panel industry is one of the most important forest-based industries in Brazil. The medium density particleboard (MDP) is currently produced and consumed worldwide and represents about 50 % of the wood panel industry in Brazil. Unlike other regions, Brazilian MDP is produced from dedicated eucalyptus plantations and heavy fuel oil is an important energy source in MDP manufacture, which may result in a different environmental profile. This paper presents a life cycle assessment of MDP panel produced in Brazil and suggests improvement opportunities by assessing alternative production scenarios.

Methods

The cradle-to-gate assessment of 1 m³ of MDP produced in Brazil considered two main subsystems: forest and industrial production. Detailed inventories for Brazilian eucalyptus production and MDP industrial production were collected as a result of technical visits to Brazilian MDP producers (foreground systems) as well as literature review (mainly background systems). The potential environmental impacts of MDP were assessed in terms of seven impact categories using CML (abiotic depletion, acidification, global warming, eutrophication, and photochemical oxidation) and USEtox (ecotoxicity and human toxicity) impact assessment methods in order to identify the main hotspots.

Results and discussion

The industrial production was responsible for most of the impacts in all impact categories, except ecotoxicity (EC). The main hotspots identified were the use of heavy fuel oil (HFO) as a thermal energy source in MDP manufacture and the production of urea–formaldehyde (UF) resin used as synthetic adhesive. Glyphosate herbicide application in soil in forestry operations was the main responsible for the impacts in EC. Scenarios for HFO substitution were assessed and results showed that substituting HFO for in-mill wood residues or diesel leads to reduced environmental impacts.

Conclusions

The identification of the main hotspots in the MDP life cycle can assist the wood panel industry to improve their environmental profile. Further research should focus on UF resin production in order to reduce its environmental impacts as well as the possibility of using alternatives resins. Other sources of wood for MDP production could also be investigated (e.g., pine wood and wood residues) to assess potential improvements.