Life cycle assessment of natural gas power plants in Thailand

Background, aim, and scope  The main primary energy for electricity in Thailand is natural gas, accounting for 73% of the grid mix. Electricity generation from natural gas combustion is associated with substantial air emissions. The two technologies currently used in Thailand, thermal and combined cycle power plant, have been evaluated for the potential environmental impacts in a “cradle-to-grid” study according to the life cycle assessment (LCA) method. This study evaluates the environmental impacts of each process of the natural gas power production over the entire life cycle and compares two different power plant technologies currently used in Thailand, namely, combined cycle and thermal. Materials and methods  LCA is used as a tool for the assessment of resource consumption and associated impacts generated from utilization of natural gas in power production. The details follow the methodology outlined in ISO 14040. The scope of this research includes natural gas extraction, natural gas separation, natural gas transmission, and natural gas power production. Most of the inventory data have been collected from Thailand, except for the upstream of fuel oil and fuel transmission, which have been computed from Greenhouse gases, Regulated Emissions, and Energy use in Transportation version 1.7 and Global Emission Model for Integrated Systems version 4.3. The impact categories considered are global warming, acidification, photochemical ozone formation, and nutrient enrichment potential (NEP). Results  The comparison reveals that the combined cycle power plant, which has a higher efficiency, performs better than the thermal power plant for global warming potential (GWP), acidification potential (ACP), and photochemical ozone formation potential (POCP), but not for NEP where the thermal power plant is preferable. Discussion  For the thermal power plant, the most significant environmental impacts are from power production followed by upstream of fuel oil, natural gas extraction, separation, and transportation. For the combined cycle power plant, the most significant environmental impacts are from power production followed by natural gas extraction, separation, and transportation. The significant difference between the two types of power production is mainly from the combustion process and feedstock in power plant. Conclusions  The thermal power plant uses a mix of natural gas (56% by energy content) and fuel oil (44% by energy content); whereas, the combined cycle power plant operates primarily on natural gas. The largest contribution to GWP, ACP, and NEP is from power production for both thermal as well as combined cycle power plants. The POCP for the thermal power plant is also from power production; whereas, for combined cycle power plant, it is mainly from transmission of natural gas. Recommendations and perspectives  In this research, we have examined the environmental impact of electricity generation technology between thermal and combined cycle natural gas power plants. This is the overview of the whole life cycle of natural gas power plant, which will help in decision making. The results of this study will be useful for future power plants as natural gas is the major feedstock being promoted in Thailand for power production. Also, these results will be used in further research for comparison with other feedstocks and power production technologies.     

Life cycle assessment of biofuels: Energy and greenhouse gas balances

The promotion of biofuels as energy for transportation in the industrialized countries is mainly driven by the perspective of oil depletion, the concerns about energy security and global warming. However due to sustainability constraints, biofuels will replace only 10 to 15% of fossil liquid fuels in the transport sector. Several governments have defined a minimum target of GHG emissions reduction for those biofuels that will be eligible to public incentives, for example a 35% emissions reduction in case of biofuels in Members States of the European Union. This article points out the significant biases in estimating GHG balances of biofuels stemming from modelling choices about system definition and boundaries, functional unit, reference systems and allocation methods. The extent to which these choices influence the results is investigated. After performing a comparison and constructive criticism of various modelling choices, the LCA of wheat-to-bioethanol is used as an illustrative case where bioethanol is blended with gasoline at various percentages (E5, E10 and E85). The performance of these substitution options is evaluated as well. The results show a large difference in the reduction of the GHG emissions with a high sensitivity to the following factors: the method used to allocate the impacts between the co-products, the type of reference systems, the choice of the functional unit and the type of blend. The authors come out with some recommendations for basing the estimation of energy and GHG balances of biofuels on principles such as transparency, consistency and accuracy.     

A survey of unresolved problems in life cycle assessment

Background, aims, and scope  Life cycle assessment (LCA) stands as the pre-eminent tool for estimating environmental effects caused by products and processes from ‘cradle to grave’ or ‘cradle to cradle.’ It exists in multiple forms, claims a growing list of practitioners, and remains a focus of continuing research. Despite its popularity and codification by organizations such as the International Organization for Standards and the Society of Environmental Toxicology and Chemistry, life cycle assessment is a tool in need of improvement. Multiple authors have written about its individual problems, but a unified treatment of the subject is lacking. The following literature survey gathers and explains issues, problems and problematic decisions currently limiting LCA’s goal and scope definition and life cycle inventory phases. Main features  The review identifies 15 major problem areas and organizes them by the LCA phases in which each appears. This part of the review focuses on the first 7 of these problems occurring during the goal and scope definition and life cycle inventory phases. It is meant as a concise summary for practitioners interested in methodological limitations which might degrade the accuracy of their assessments. For new researchers, it provides an overview of pertinent problem areas toward which they might wish to direct their research efforts. Results and discussion  Multiple problems occur in each of LCA’s four phases and reduce the accuracy of this tool. Considering problem severity and the adequacy of current solutions, six of the 15 discussed problems are of paramount importance. In LCA’s first two phases, functional unit definition, boundary selection, and allocation are critical problems requiring particular attention. Conclusions and recommendations  Problems encountered during goal and scope definition arise from decisions about inclusion and exclusion while those in inventory analysis involve flows and transformations. Foundational decisions about the basis of comparison (functional unit), bounds of the study, and physical relationships between included processes largely dictate the representativeness and, therefore, the value of an LCA. It is for this reason that problems in functional unit definition, boundary selection, and allocation are the most critical examined in the first part of this review.

A survey of unresolved problems in life cycle assessment

Background, aims, and scope  Life cycle assessment (LCA) stands as the pre-eminent tool for estimating environmental effects caused by products and processes from ‘cradle to grave’ or ‘cradle to cradle.’ It exists in multiple forms, claims a growing list of practitioners and remains a focus of continuing research. Despite its popularity and codification by organizations such as the International Organization for Standardization and the Society of Environmental Toxicology and Chemistry, life cycle assessment is a tool in need of improvement. Multiple authors have written about its individual problems, but a unified treatment of the subject is lacking. The following literature survey gathers and explains issues, problems and problematic decisions currently limiting LCA’s impact assessment and interpretation phases. Main features  The review identifies 15 major problem areas and organizes them by the LCA phases in which each appears. This part of the review focuses on the latter eight problems. It is meant as a concise summary for practitioners interested in methodological limitations which might degrade the accuracy of their assessments. For new researchers, it provides an overview of pertinent problem areas toward which they might wish to direct their research efforts. Having identified and discussed LCA’s major problems, closing sections highlight the most critical problems and briefly propose research agendas meant to improve them. Results and discussion  Multiple problems occur in each of LCA’s four phases and reduce the accuracy of this tool. Considering problem severity and the adequacy of current solutions, six of the 15 discussed problems are of paramount importance. In LCA’s latter two phases, spatial variation and local environmental uniqueness are critical problems requiring particular attention. Data availability and quality are identified as critical problems affecting all four phases. Conclusions and recommendations  Observing that significant efforts by multiple researchers have not resulted in a single, agreed upon approach for the first three critical problems, development of LCA archetypes for functional unit definition, boundary selection and allocation is proposed. Further development of spatially explicit, dynamic modeling is recommended to ameliorate the problems of spatial variation and local environmental uniqueness. Finally, this paper echoes calls for peer-reviewed, standardized LCA inventory and impact databases, and it suggests the development of model bases. Both of these efforts would help alleviate persistent problems with data availability and quality.

Life cycle assessment (LCA) of industrial milk production

A Life Cycle Assessment (LCA) was carried out for milk production extending from the origin of the inputs to the agricultural step to the consumer phase and the waste management of the packaging. Three Norwegian dairies of different sizes and degree of automation were studied. The main objectives were to find any hot spots in the life cycle of milk, to determine the significance of the dairy size and degree of automation, and to study the influence of transport. The agriculture was found to be the main hot spot for almost all the environmental themes studied, although the dairy processing, packaging, consumer phase and waste management were also of importance. The consumer phase was the main contributor to photo-oxidant formation and important regarding eutrophication. The small dairy was found to have a greater environmental impact than the middle-sized and the largest dairies. The transport did not have any major influence.     

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 and socioeconomic evaluation of the illicit crop substitution policy in Colombia

The peace treaty of Colombia contemplates a crop substitution policy seeking to replace coca crops with legal alternatives. Although crop substitution diverts funding of illegal activities and provides an income to farmers, it is important to understand how the change to a variety of legal crops (coffee, sugarcane, and cacao) affects the income of farmers, and whether there is an environmental advantage of a crop over another. This study applies life cycle assessment (LCA) coupled with socioeconomic indicators to two regions, Putumayo and Catatumbo, over different policy scenarios. LCA results show that a policy success does not ensure a lower environmental impact across the board. Legal crops consume less fuel than coca crops, which reduce fuel‐related impacts, but the use of fertilizer in coffee and pesticide use in sugarcane increase toxicity‐related impacts. The results, however, are affected by a lack of characterization factors of agrochemicals, but once these are replaced by proxies, coca crops appear to have greater toxicity impacts. In terms of individual crops, cacao crops have a lower environmental impact than coffee and sugarcane, but it also takes the longest to harvest, which may pose a financial risk to farmers. The socioeconomic analysis reveals that for Catatumbo farmers, a policy success reduces the income, whereas for Putumayo farmers, a policy success increases income and job generation. In general, it was observed that the dynamics of the illegal supply chain vary for each region, influencing the environmental and socioeconomic outcome of the substitution policy.     

基于在线供应链调查的产品生命周期评价

产品生命周期评价(LCA)中的供应链数据收集非常困难而且效率低下,因而在产品LCA研究中常常近似处理、甚至忽略供应链实际生产过程,严重影响了LCA的数据质量与可信度。开发专门的供应链数据收集工具是解决这一问题的有效途径。介绍了可进行在线供应链调查、建模与计算分析的LCA系统e Footprint,基于该系统提出了在线的LCA工作方法,通过长虹美菱冰箱的应用案例验证了系统与方法的可行性,为提高产品LCA的效率和质量提供了新的解决方案。     

Life cycle assessment of Australian automotive door skins

Background, aim, and scope  Policy initiatives, such as the EU End of Life Vehicle (ELV) Directive for only 5% landfilling by 2015, are increasing the pressure for higher material recyclability rates. This is stimulating research into material alternatives and end-of-life strategies for automotive components. This study presents a Life Cycle Assessment (LCA) on an Australian automotive component, namely an exterior door skin. The functional unit for this study is one door skin set (4 exterior skins). The material alternatives are steel, which is currently used by Australian manufacturers, aluminium and glass-fiber reinforced polypropylene composite. Only the inputs and outputs relative to the door skin production, use and end-of-life phases were considered within the system boundary. Landfill, energy recovery and mechanical recycling were the end-of-life phases considered. The aim of the study is to highlight the most environmentally attractive material and end-of-life option. Methods  The LCA was performed according to the ISO 14040 standard series. All information considered in this study (use of fossil and non fossil based energy resources, water, chemicals etc.) were taken up in in-depth data. The data for the production, use and end-of-life phases of the door skin set was based upon softwares such as SimaPro and GEMIS which helped in the development of the inventory for the different end-of-life scenarios. In other cases, the inventory was developed using derivations obtained from published journals. Some data was obtained from GM-Holden and the Co-operative research Centre for Advanced Automotive Technology (AutoCRC), in Australia. In cases where data from the Australian economy was unavailable, such as the data relating to energy recovery methods, a generic data set based on European recycling companies was employed. The characterization factors used for normalization of data were taken from (Saling et. al. Int J Life Cycle Assess 7(4):203–218 2002) which detailed the method of carrying out an LCA. Results  The production phase results in maximum raw material consumption for all materials, and it is higher for metals than for the composite. Energy consumption is greatest in the use phase, with maximum consumption for steel. Aluminium consumes most energy in the production phase. Global Warming Potential (GWP) also follows a trend similar to that of energy consumption. Photo Oxidants Creation Potential (POCP) is the highest for the landfill scenario for the composite, followed by steel and aluminium. Acidification Potential (AP) is the highest for all the end-of-life scenarios of the composite. Ozone Depletion Potential (ODP) is the highest for the metals. The net water emissions are also higher for composite in comparison to metals despite high pollution in the production phases of metallic door skins. Solid wastes are higher for the metallic door skins. Discussion  The composite door skin has the lowest energy consumption in the production phase, due to the low energy requirements during the manufacturing of E-glass and its fusion with polypropylene to form sheet molding compounds. In general, the air emissions during the use phase are strongly dependent on the mass of the skins, with higher emissions for the metals than for the composite. Material recovery through recycling is the highest in metals due to efficient separation techniques, while mechanical recycling is the most efficient for the composite. The heavy steel skins produce the maximum solid wastes primarily due to higher fuel consumption. Water pollution reduction benefit is highest in case of metals, again due to the high efficiency of magnetic separation technique in the case of steel and eddy current separation technique in the case of aluminium. Material recovery in these metals reduces the amount of water needed to produce a new door skin set (water employed mainly in the ingot casting stage). Moreover, the use of heavy metals, inorganic salts and other chemicals is minimized by efficient material recovery. Conclusions  The use of the studied type of steel for the door skins is a poor environmental option in every impact category. Aluminium and composite materials should be considered to develop a more sustainable and energy efficient automobile. In particular, this LCA study shows that glass-fiber composite skins with mechanical recycling or energy recovery method could be environmentally desirable, compared to aluminium and steel skins. However, the current limit on the efficiency of recycling is the prime barrier to increasing the sustainability of composite skins. Recommendations and perspectives  The study is successful in developing a detailed LCA for the three different types of door skin materials and their respective recycling or end-of-life scenarios. The results obtained could be used for future work on an eco-efficiency portfolio for the entire car. However, there is a need for a detailed assessment of toxicity and risk potentials arising from each of the four different types of door skin sets. This will require greater communication between academia and the automotive industry to improve the quality of the LCA data. Sensitivity analysis needs to be performed such as the assessment of the impact of varying substitution factors on the life cycle of a door skin. Incorporation of door skin sets made of new biomaterials need to be accounted for as another functional unit in future LCA studies. Discussion contributions to this article from the readership would the highly welcome. The authors     

System expansion and allocation in life cycle assessment of milk and beef production

Background, Goal and Scope  System expansion is a method used to avoid co-product allocation. Up to this point in time it has seldom been used in LCA studies of food products, although food production systems often are characterised by closely interlinked sub-systems. One of the most important allocation problems that occurs in LCAs of agricultural products is the question of how to handle the co-product beef from milk production since almost half of the beef production in the EU is derived from co-products from the dairy sector. The purpose of this paper is to compare different methods of handling co-products when dividing the environmental burden of the milk production system between milk and the co-products meat and surplus calves. Main Features  This article presents results from an LCA of organic milk production in which different methods of handling the co-products are examined. The comparison of different methods of co-product handling is based on a Swedish LCA case study of milk production where economic allocation between milk and meat was initially used. Allocation of the co-products meat and surplus calves was avoided by expanding the milk system. LCA data were collected from another case study where the alternative way of producing meat was analysed, i.e. using a beef cow that produces one calf per annum to be raised for one and a half year. The LCA of beef production was included in the milk system. A discussion is conducted focussing on the importance of modelling and analysing milk and beef production in an integrated way when foreseeing and planning the environmental consequences of manipulating milk and beef production systems. Results  This study shows that economic allocation between milk and beef favours the product beef. When system expansion is performed, the environmental benefits of milk production due to its co-products of surplus calves and meat become obvious. This is especially connected to the impact categories that describe the potential environmental burden of biogenic emissions such as methane and ammonia and nitrogen losses due to land use and its fertilising. The reason for this is that beef production in combination with milk can be carried out with fewer animals than in sole beef production systems. Conclusion, Recommendation and Perspective  Milk and beef production systems are closely connected. Changes in milk production systems will cause alterations in beef production systems. It is concluded that in prospective LCA studies, system expansion should be performed to obtain adequate information of the environmental consequences of manipulating production systems that are interlinked to each other.     

Life cycle assessment of emerging technologies: A review

In recent literature, prospective application of life cycle assessment (LCA) at low technology readiness levels (TRL) has gained immense interest for its potential to enable development of emerging technologies with improved environmental performances. However, limited data, uncertain functionality, scale up issues and uncertainties make it very challenging for the standard LCA guidelines to evaluate emerging technologies and requires methodological advances in the current LCA framework. In this paper, we review published literature to identify major methodological challenges and key research efforts to resolve these issues with a focus on recent developments in five major areas: cross‐study comparability, data availability and quality, scale‐up issues, uncertainty and uncertainty communication, and assessment time. We also provide a number of recommendations for future research to support the evaluation of emerging technologies at low technology readiness levels: (a) the development of a consistent framework and reporting methods for LCA of emerging technologies; (b) the integration of other tools with LCA, such as multicriteria decision analysis, risk analysis, technoeconomic analysis; and (c) the development of a data repository for emerging materials, processes, and technologies.     

Life cycle assessment of biodiesel production from microalgae in ponds

This paper analyses the potential environmental impacts and economic viability of producing biodiesel from microalgae grown in ponds. A comparative Life Cycle Assessment (LCA) study of a notional production system designed for Australian conditions was conducted to compare biodiesel production from algae (with three different scenarios for carbon dioxide supplementation and two different production rates) with canola and ULS (ultra-low sulfur) diesel. Comparisons of GHG (greenhouse gas) emissions (g CO₂-e/t km) and costs (¢/t km) are given. Algae GHG emissions (−27.6 to 18.2) compare very favourably with canola (35.9) and ULS diesel (81.2). Costs are not so favourable, with algae ranging from 2.2 to 4.8, compared with canola (4.2) and ULS diesel (3.8). This highlights the need for a high production rate to make algal biodiesel economically attractive.     

Life cycle assessment of recirculating aquaculture systems: A case of Atlantic salmon farming in China

Recirculating aquaculture systems (RAS) are an alternative technology to tackle the major environmental challenges associated with conventional cage culture systems. In order to systematically assess the environmental performance of RAS farming, it is important to take the whole life cycle into account so as to avoid ad hoc and suboptimal environmental measures. So far, the application of life cycle assessment (LCA) in aquaculture, especially to indoor RAS, is still in progress. This study reports on an LCA of Atlantic salmon harvested at an indoor RAS farm in northern China. Results showed that 1 tonne live‐weight salmon production required 7,509 kWh farm‐level electricity and generated 16.7 tonnes of CO₂ equivalent (eq), 106 kg of SO₂ eq, 2.4 kg of P eq, and 108 kg of N eq (cradle‐to‐farm gate). In particular, farm‐level electricity use and feed product were identified as primary contributors to eight of nine impact categories assessed (54–95% in total), except the potential marine eutrophication (MEU) impact (dominated by the grow‐out effluents). Among feed ingredients (on a dry‐weight basis), chicken meal (5%) and krill meal (8%) dominated six and three, respectively, of the nine impact categories. Suggested environmental improvement measures for this indoor RAS farm included optimization of stocking density, feeding management, grow‐out effluent treatment, substitution of feed ingredients, and selection of electricity generation sources. In a generic context, this study can contribute to a better understanding of the life cycle environmental impacts of land‐based salmon RAS operations, as well as science‐based communication among stakeholders on more eco‐friendly farmed salmon.     

Material life cycle assessment in china

From the very beginning, the research of Material Life Cycle Assessment (MLCA) has been an important part of the ecomaterials research in China, and large numbers of researchers have been focusing their efforts on it. From 1998, and supported by the National High-tech Program-863 Projects, the study of some typical materials has been put into practice. Thus far, the first phase of the project has been finished smoothly. The practical MLCA methods have been developed, and the manufacturing technologies and processes of the steel and iron, aluminum, cement, ceramic, polymer and construction coatings have been assessed. The relevant assessment software has been developed. Reference systems are being set up for evaluation by studying typical materials. In this paper, the main achievements are reviewed. Some other developments of MLCA in China are also introduced.     

Life cycle assessment of tractors

This study was intended to evaluate the environmental impact, and potential improvements for a typical tractor model (LT360D) of LG Machinery Co., Ltd. The life cycle of this study includes all stages from raw material acquisition up to final disposal. The eco-indicator 95 method was employed to perform an impact assessment. The result of this study is expected to represent the environmental feature of typical diesel vehicles at each life cycle stage. This study is a starting point of building life cycle inventories for typical off-road diesel tractors. With this result, environmental weak points of the tractor have been defined, and major improvement strategies have been set up to develop the ‘Green Tractor’.     

Cradle-to-gate life cycle inventory and assessment of pharmaceutical compounds

Background, Goal and Scope  The research presented here represents one part of GlaxoSmithKline’s (GSK) efforts to identify and improve the life cycle impact profile of pharmaceutical products. The main goal of this work was to identify and analyze the cradle-to-gate environmental impacts in the synthesis of a typical Active Pharmaceutical Ingredient (API). A cradle-to-gate life cycle assessment of a commercial pharmaceutical product is presented as a case study. Methods  Life cycle inventory data were obtained using a modular gate-to-gate methodology developed in partnership with North Carolina State University (NCSU) while the impact assessment was performed utilizing GSK’s sustainability metrics methodology. Results and Discussion  Major contributors to the environmental footprint of a typical pharmaceutical product were identified. The results of this study indicate that solvent use accounts for a majority of the potential cradle-to-gate impacts associated with the manufacture of the commercial pharmaceutical product under study. If spent solvent is incinerated instead of recovered the life-cycle profile and impacts are considerably increased. Conclusions  This case study provided GSK with key insights into the life-cycle impacts of pharmaceutical products. It also helped to establish a well-documented approach to using life cycle within GSK and fostered the development of a practical methodology that is applicable to strategic decision making, internal business processes and other processes and tools.     

Integration of life cycle assessment in the environmental information system

Background, aim, and scope  As the sustainability improvement becomes an essential business task of industry, a number of companies are adopting IT-based environmental information systems (EIS). Life cycle assessment (LCA), a tool to improve environmental friendliness of a product, can also be systemized as a part of the EIS. This paper presents a case of an environmental information system which is integrated with online LCA tool to produce sets of hybrid life cycle inventory and examine its usefulness in the field application of the environmental management. Main features  Samsung SDI Ltd., the producer of display panels, has launched an EIS called Sustainability Management Initiative System (SMIS). The system comprised modules of functions such as environmental management system (EMS), green procurement (GP), customer relation (e-VOC), eco-design, and LCA. The LCA module adopted the hybrid LCA methodology in the sense that it combines process LCA for the site processes and input–output (IO) LCA for upstream processes to produce cradle-to-gate LCA results. LCA results from the module are compared with results of other LCA studies made by the application of different methodologies. The advantages and application of the LCA system are also discussed in light of the electronics industry. Results and discussion  LCA can play a vital role in sustainability management by finding environmental burden of products in their life cycle. It is especially true in the case of the electronics industry, since the electronic products have some critical public concerns in the use and end-of-life phase. SMIS shows a method for hybrid LCA through online data communication with EMS and GP module. The integration of IT-based hybrid LCA in environmental information system was set to begin in January 2006. The advantage of the comparing and regular monitoring of the LCA value is that it improves the system completeness and increases the reliability of LCA. By comparing the hybrid LCA and process LCA in the cradle-to-gate stage, the gap between both methods of the 42-in. standard definition plasma display panel (PDP) ranges from 1% (acidification impact category) to −282% (abiotic resource depletion impact category), with an average gap of 68.63%. The gaps of the impact categories of acidification (AP), eutrophication (EP), and global warming (GWP) are relatively low (less than 10%). In the result of the comparative analysis, the strength of correlation of three impact categories (AP, EP, GWP) shows that it is reliable to use the hybrid LCA when assessing the environmental impacts of the PDP module. Hybrid LCA has its own risk on data accuracy. However, the risk is affordable when it comes to the comparative LCA among different models of similar product line of a company. In the results of 2 years of monitoring of 42-in. Standard definition PDP, the hybrid LCA score has been decreased by 30%. The system also efficiently shortens man-days for LCA study per product. This fact can facilitate the eco-design of the products and can give quick response to the customer's inquiry on the product's eco-profile. Even though there is the necessity for improvement of process data currently available, the hybrid LCA provides insight into the assessments of the eco-efficiency of the manufacturing process and the environmental impacts of a product. Conclusions and recommendations  As the environmental concerns of the industries increase, the need for environmental data management also increases. LCA shall be a core part of the environmental information system by which the environmental performances of products can be controlled. Hybrid type of LCA is effective in controlling the usual eco-profile of the products in a company. For an industry, in particular electronics, which imports a broad band of raw material and parts, hybrid LCA is more practicable than the classic LCA. Continuous efforts are needed to align input data and keep conformity, which reduces data uncertainty of the system.     

Life cycle assessment of pasture-based suckler steer weanling-to-beef production systems: Effect of breed and slaughter age

Demand for beef produced from pasture-based diets is rising as it is perceived to be healthier, animal friendly and good for the environment. Animals reared on a solely grass forage diet, however, have a lower growth rate than cereal-fed animals and consequently are slaughtered at an older age. This study focused on the former by conducting life cycle assessments of beef production systems offering only fresh or conserved grass, and comparing them to a conventional pasture-based beef production system offering concentrate feeding during housing. The four suckler weanling-to-beef production systems simulated were: (i) Steers produced to slaughter entirely on a grass forage diet at 20 months (GO-20); (ii) Steers produced to slaughter entirely on a grass forage diet at 24 months (GO-24); (iii) Steers produced to slaughter on a grass forage diet with concentrate supplementation during housing (GC-24), and (iv) Steers produced to slaughter entirely on a grass forage diet at 28 months (GO-28). Two breed types were evaluated: early-maturing and late-maturing (LM). The environmental impacts assessed were global warming potential (GWP), non-renewable energy (NRE), acidification potential (AP), eutrophication potential (marine (MEP) and freshwater) were expressed per animal, per kg live weight gain (LWG), kg carcass weight gain, and kg meat weight gain (MWG). The GO-20 production system had the lowest environmental impact across all categories and functional units for both breeds. Extending age at slaughter increased environmental impact across all categories per animal. The LWG response of EM steers to concentrate feed supplementation in GC-24 was greater than the increase in total environmental impact resulting in GC-24 having a lower environmental impact across categories per kg product than GO-24. Concentrate feed supplementation had a similar effect on LM steers with the exception of NRE and AP. The increase in daily LWG in the third grazing season in comparison to the second grazing and housing resulted in GO-28 having lower GWP, NRE, AP, and MEP per kg product than GO-24. Early-maturing steers had lower environmental impact than LM when expressed per kg LWG. However the opposite occurred when impacts were expressed per kg MWG, despite LM steers producing the least LWG. The LM steers compensated for poor LWG performance by having superior carcass traits, which caused the breed to have the lowest environmental impact per kg MWG. The results reaffirms the importance of functional unit and suggests reducing the environmental impact of LWG does not always translate into improvements in the environmental performance of meat.     

农业生命周期评价研究进展

作为评价产品系统全链条环境影响的有效工具,生命周期评价（LCA）方法已广泛用于工业领域。农业领域也面临着高强度的资源和环境压力,LCA在农业领域的应用应运而生。旨在综述已有农业LCA研究的基础上,鉴别农业LCA应用存在的问题,并为农业LCA未来的发展提出建议。目前农业LCA存在系统边界和功能单位界定不明晰、缺少区域清单数据库、生命周期环境影响评价模型（LCIA）不能准确反映农业系统环境影响、结果解释存在误区等方面的问题。为了科学准确地衡量农业系统的环境影响,促进农业系统的可持续发展,文章认为农业LCA应该从以下几个方面加强研究,即科学界定评价的参照系、系统边界的扩大及功能单位的合理选取、区域异质性数据库构建与LCIA模型开发、基于组织农业LCA的开发以及对于利益相关者行为的研究。