Life cycle assessment (LCA) applied to the process industry: a review

Purpose

Life cycle assessment (LCA) methodology is a well-established analytical method to quantify environmental impacts, which has been mainly applied to products. However, recent literature would suggest that it has also the potential as an analysis and design tool for processes, and stresses that one of the biggest challenges of this decade in the field of process systems engineering (PSE) is the development of tools for environmental considerations.

Method

This article attempts to give an overview of the integration of LCA methodology in the context of industrial ecology, and focuses on the use of this methodology for environmental considerations concerning process design and optimization.

Results

The review identifies that LCA is often used as a multi-objective optimization of processes: practitioners use LCA to obtain the inventory and inject the results into the optimization model. It also shows that most of the LCA studies undertaken on process analysis consider the unit processes as black boxes and build the inventory analysis on fixed operating conditions.

Conclusions

The article highlights the interest to better assimilate PSE tools with LCA methodology, in order to produce a more detailed analysis. This will allow optimizing the influence of process operating conditions on environmental impacts and including detailed environmental results into process industry.     

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 capacity roadmap (section 1): decision-making support using LCA

When life cycle assessment (LCA) results do not show a clear and certain environmental preference of one choice over one or several alternatives, current methods are limited in their ability to inform decision-makers. To address this and related cross-cutting issues, a group of LCA practitioners has been working on a roadmap for capacity development in LCA. The roadmap is identifying common needs for development in LCA, which can then be addressed by the broader LCA community. The roadmap document on decision-making support, having undergone a public comment period, outlines the current state as well as needs and milestones to ensure progress continues apace. The roadmap document, available for download, covers five main areas of development: (1) performance measures of confidence, which identify the acceptable uncertainty for study results, while minimizing expenditures; (2) selection of impact categories, an area with multiple existing methods. The roadmap suggests codifying these methods and identifying their suitability to various applications; (3) normalization; while several methods of normalization are in use, the method with the greatest acceptance in the LCA community (i.e., relying on total or per capita regional emissions/extractions) has a number of methodological drawbacks; (4) weighting, which is a form of multi-criteria decision analysis (MCDA). The broader MCDA field can enrich LCA by providing studied methods of assessing trade-offs; and (5) visualization of results. Many other LCA capacity needs would benefit from documentation. These include but are not limited to the following: addressing ill-characterized uncertainty, life cycle inventory data needs, data format needs, and tool capabilities. Other roadmapping groups are forming and are looking for practitioners to support the effort.     

Life cycle assessment of dairy production systems in Inner Mongolia: reiterate LCA modeling approaches

The International Journal of Life Cycle Assessment - The selection of different LCA modeling approaches can lead to inconsistent applications and results. Here, we proposed decision trees to...     

Representing crop rotations in life cycle assessment: a review of legume LCA studies

The International Journal of Life Cycle Assessment - There is an imperative to accurately assess the environmental sustainability of crop system interventions in the context of food security and...     

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.     

Application of life cycle assessment to the LCA case studies single superphosphate production

Goal, Scope and Background  

There is a competition between wet and thermal routes for phosphate fertilizers manufacture. In the Brazilian case, the thermal route is represented by thermophosphate. This fertilizer is considered the most adequate one for Brazilian agricultural conditions; its main restriction is the intensive consumption of energy necessary for its production. The wet route uses sulfuric acid to direcdy produce the single superphosphate (SSP) or the intermediate phosphoric acid, which will be used to result in triple superphosphate (TSP) and ammonium phosphate production. The main restriction of the wet route is the large amount of phosphogypsum generated in phosphoric acid production. Envisaged is an environmental comparison of both routes using LCA methodology. This paper presents the LCA for SSP production. The goal of the study is to establish the Environmental Profile of this fertilizer. Eight impact categories were selected for the study. The system boundaries was defined for a ‘cradle to gate’ approach, including extraction of natural resources, intermediate products, and production.     

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’.     

Life cycle assessment of a multi-material car component

Background, Aims and Scope In recent years, the automotive industry has been experiencing an increasing concern with environmental requirements. A particular focus is being given to light-weighting of cars, to reducing fuel consumption and to the use of different recycling materials. Consequently, decisions on product design and development must involve economic and technological as well as environmental considerations. In adequate conditions, the LCA methodology enables one to assist an effective integration of the environmental considerations in the decision-making process [1]. In this paper, a multi-material car component which is part of the current automotive brake system, has been modified by its original manufacturer. Such a modification included the use of a new multi-material injection moulding process and the consumption of recyclable materials. The new and the current component were comparatively assessed throughout their life cycles in order to evaluate their respective environmental impacts and, thus, to verify if the new component offers a lower environmental load. The results described in this paper are part of the outcome of a broader research project involving industrial companies, university, technological centres and research institutes based in Portugal, Spain and Germany. Main Features The car component under focus has four subcomponents whose base materials consist of steel and plastic. The LCA methodology is used to evaluate two scenarios describing the new car component, on the one hand, and the reference scenario, which consists of the existing car component, on the other. The former results from the selection of new subcomponents materials, aiming to use a new production process together with a recycling strategy. Results and Discussion The inventory analysis shows a lower energy consumption in the alternative scenario (4.2 MJ) compared to the reference scenario (6.1 MJ). Most of that energy is still non-renewable, relating in particular to crude consumption in the car use phase and in the production phase (transports and plastics production). The life cycle inventory analysis indicates also that the alternative scenario has lower air emissions of CO₂, CO, NO_x, SO_x, NM VOC and PM10, as well as lower solid wastes and water emissions of oils and BOD5. Otherwise, the water emissions of undissolved substances and COD are higher for the alternative scenario. Most of the energy consumed and the air pollutants inventoried occur as a consequence of the use phase. Otherwise, for most of the life cycle water emissions inventoried and solid wastes, the production phase is the major contributor. The impact assessment, performed with the CML method, allows one to conclude that the alternative scenario exhibits lower results in all the impact categories. Both scenarios have similar environmental profiles, being: (i) the use phase, the major contributor for the abiotic depletion, global warming, photochemical oxidation, acidification and eutrophication; and (ii) the production phase, the main contributor for ozone depletion, human toxicity, fresh water aquatic ecotoxicity, marine aquatic ecotoxicity and terrestrial ecotoxicity. The sensitivity analysis, with respect to the fuel consumption reduction value, the impact assessment method and the final disposal scenario, performed in this study allows one to confirm, as a main conclusion, that the alternative scenario is environmentally preferable to the reference scenario. Conclusion The results obtained through the application of the LCA methodology enable one to conclude that the alternative component has a lower environmental load than the reference component. Recommendations and Perspectives Considering that the time required for the inventory data collection is a critical issue in LCA practise, the insights provided by this particular case study are likely to be useful to product developers in the car component manufacturing industry, particularly to brake system manufacturers supporting the environmental design within the sector.     

Life cycle assessment of a basic lager beer

The current case study was performed to determine and evaluate the environmental impacts, and to look for possible improvements in the production and distribution of a basic lager beer that is packed into multi-packs of glass bottles. The life cycle investigated includes the stages from agricultural production up to the delivering of products to the shops, the consumption phase has been excluded. Raw water treatment and energy production and use have been included, and the contribution of different sub-systems inside of the life cycle to climate change, acidification, eutrophication, oxygen depletion and summer smog were assessed. The investigation resulted with several suggestions for improving the product and environmental performance of brewery.     

Life cycle impact assessment sophistication

On November 29 – 30, 1998 in Brussels, an international workshop was held to discuss Life Cycle Impact Assessment (LCIA) Sophistication. Approximately 50 LCA experts attended the workshop from North America, Europe, and Asia. Prominent practitioners and researchers were invited to present a critical review of the associated factors, including the current limitations of available impact assessment methodologies and a comparison of the alternatives in the context of uncertainty. Each set of presentations, organised into three sessions, was followed by a discussion session to encourage international discourse with a view to improving the understanding of these crucial issues. The discussions were focused around small working groups of LCA practitioners and researchers, selected to include a balance of representatives from industry, government and academia. This workshop provided the first opportunity for International experts to address the issues related to LCIA Sophistication in an open format. Among the topics addressed were: 1) the inclusion or exclusion of backgrounds and thresholds in LCIA, 2) the necessity and practicality regarding the sophistication of the uncertainty analysis, 3) the implications of allowing impact categories to be assessed at “midpoint” vs. at “endpoint” level, 4) the difficulty of assessing and capturing the comprehensiveness of the environmental health impact category, 5) the implications of cultural/philosophical views, 6) the meaning of terms like science-based and environmental relevance in the coming ISO LCIA standard, 7) the dichotomy of striving for consistency while allowing the incorporation of state-of-the-art research, 8) the role of various types of uncertainty analysis, and 9) the role of supporting environmental analyses (e.g., risk assessments). Many of these topics addressed the need for increased sophistication in LCIA, but recognised the conflict this might have in terms of the comprehensiveness and holistic character of LCA, and LCIA in particular. The participants concluded that the exchange of ideas in this format was extremely valuable and would like to plan successive International workshops on related themes.     

Life cycle assessment of zircon sand

The International Journal of Life Cycle Assessment - To support the needs of downstream users of zircon sand and other industry stakeholders, the Zircon Industry Association (ZIA) conducted an...     

Life cycle assessment of nickel products

Purpose

To support the data requirements of stakeholders, the Nickel Institute (NI) conducted a global life cycle impact assessment (LCIA) to show, with indicators, the potential environmental impacts of the production of nickel and ferronickel from mine to refinery gate. A metal industry wide agreed approach on by-products and allocation was applied.

Methods

Nine companies, comprising 19 operations, contributed data, representing 52 % of global nickel metal production and 40 % of global ferronickel production. All relevant pyro- and hydrometallurgical production routes were considered, across most major nickel-producing regions. Data from Russia, the biggest nickel-producing nation, was included; the Chinese industry did not participate. 2011 was chosen as reference year for data collection. The LCIA applied allocation of impacts of by-products using both economic and mass allocations. A sensitivity analysis was conducted to further understand the relevance and impact of the different allocation approaches.

Results and discussion

The primary extraction and refining steps are the main contributors to primary energy demand (PED) and global warming potential (GWP), contributing 60 and 70 % to the PED for the production of 1 kg class I nickel and 1 kg nickel in ferronickel, respectively, and over 55 % of the GWP for both nickel products. The PED for 1 kg class 1 nickel was calculated to be 147 MJ, whilst the PED for 1 kg nickel in ferronickel was calculated to be three times higher at 485 MJ. The main factors influencing energy demand in the metallurgical processes are ore grade and ore mineralogy. Sulphidic ore is less energy intensive to process than oxidic ore. Eighty-six percent of the production volume from class 1 nickel producers, in this study, is from sulphidic ore. All ferronickel was produced from oxidic ore. The LCIA results, including a sensitivity analysis of the impact of producers with higher and lower PED, reflect the influence of the production route on energy demand and on environmental impact categories.

Conclusions

Conformant to relevant ISO standards, and backed-up with a technical and critical review, this LCIA quantifies the environmental impacts associated with the production of the main nickel products. With this study, a sound background dataset for downstream users of nickel has been provided. The Nickel Institute aims to update their data in the coming years to reflect upon changes in technology, energy efficiency, and raw material input.

     

Life cycle impact assessment of pesticides

Pesticides are biologically active substances that are directly released to the environment during the use phase of their life cycle. Pesticides are widely used and play an important role in the production of vital goods such as food, feedstuffs and cotton. The Discussion Forum 19 focused on the impact assessment of pesticides applied in agriculture. The discussion forum started with three talks about new approaches to estimate pesticide emissions and to assess their fate in the environment. The following short presentations illustrated the application of some of these methods in case studies and highlighted the problem of data availability. The last two presentations provided insight into risk assessment models used for pesticide registration from a company perspective and from the viewpoint of the authorities.