Life cycle inventory analysis of granite production from cradle to gate

Purpose

Granite is a traditional high-quality material that is widely used in construction. A key strategy that is increasingly promoted to highlight the competitiveness of materials is life cycle environmental performance. Due to the lack of comprehensive life cycle inventories (LCIs), the environmental characterisation of granite products has received little attention in scientific literature. In this paper, a complete LCI of the production chain of intermediate and finished granite products is provided and analysed.

Methods

The Spanish granite production industry, which is the second major European producer and the seventh worldwide, is examined. The reference unit is defined as 1 m² of finished granite tiles with dimensions 60?×?40?×?2 cm used for indoor and outdoor applications. Input and output data were collected through the distribution of technical data collection surveys to quarries and processing facilities and via on-site visits. During data calculation and validation, technical support was provided by technicians from the Spanish Cluster of Granite Producers. The LCI data describe the industrial activity in baseline year 2010 that corresponds to a total production volume of 48,052 m³ of quarried granite and a net of 881,406 m² of processed granite.

Results and discussion

The production of 1 m² of polished granite tiles requires 28 kWh of electricity, 23 MJ of diesel, 103 l of water, and 7 kg of ancillary materials. Sandblasted, flamed or bush-hammered finishes applied to granite tiles have a minimal effect on their total energy and material requirements but significantly affect their water consumption. Electrical energy, cooling water and steel are the major industrial requirements in which granite sawing is the most demanding process. The resource efficiency of the production chain is 0.31. Approximately 117 kg of granite are wasted per square meter of granite tiles that are produced (53 kg). Seventy-four percent of granite waste is composed of granite scrap, which becomes a marketable by-product. The predominant source of granite waste is the sawdust that is generated during stone-cutting operations.

Conclusions

LCIs provide the relevant information required to characterise the environmental performance of granite production and products. LCI data can be easily managed by users due to the disaggregation into unit processes. LCI data can be used to analyse the environmental burden associated with intermediary granite products, such as granite blocks, sawn granite slabs and finished granite slabs, and to analyse the environmental burden of finished granite tiles according to the corresponding net production volumes.

Recommendations

LCI dataset of granite production should be extended to include alternative production technologies, such as diamond multiwire machines for sawing granite, which is an increasingly competitive production technology with interesting properties for cleaner production. Strong competitive granite industries, such as the industries in China, India and Brazil, should also provide LCIs of granite products to transparently compare different product chains, identify environmental strategies on the sector level, and promote the green procurement of granite products.     

Life cycle inventory of medium density fibreboard

Goal, Scope and Background Wood is the most important renewable material. The management of wood appears to be a key action to optimise the use of resources and to reduce the environmental impact associated with mankind’s activities. Wood-based products must be analysed considering the two-fold nature of wood, commonly used as a renewable material or regenerative fuel. Relevant, up-to-date environmental data are needed to allow the analysis of wood-based products. The main focus of this study is to provide comprehensive data of one key wood board industry such as the Medium Density Fibreboard (MDF). Moreover, the influence of factors with strong geographical dependence, such as the electricity profile and final transport of the product, is analysed. In this work, International Organization for Standardization standards (ISO 14040-43) and Ecoindicator 99 methodology have been considered to quantify the potential environmental impact associated to the system under study. Three factories, considered representative of the ‘state of art’, were selected to study the process in detail: two Spanish factories and a Chilean one, with a process production of around 150,000 m³ per year. The system boundaries included all the activities taking place into the factory as well as the activities linked to the production of the main chemicals used in the process, energy inputs and transport. All the data related to the inputs and outputs of the process were obtained by on-site measurements during a one-year period. A sensitive analysis was carried out taking into account the influence of the final transport of the product and the dependence on the electricity generation profile. Life Cycle Inventory Analysis LCI methodology has been used for the quantification of the impacts of the MDF manufacture. The process chain can be subdivided in three main subsystems: wood preparation, board shaping and board finishing. The final transport of the product was studied as a different subsystem, considering scenarios from local to transoceanic distribution and three scenarios of electricity generation profile were assessed. The system was characterised with Ecoindicator 99 methodology (hierarchic version) in order to identify the ‘hot spots’. Damage to Human Health, Ecosystem Quality and Resources are mainly produced by the subsystem of Wood Preparation (91.1%, 94.8% and 94.1%, respectively). The contribution of the subsystem of Board Finishing is considerably lower, but also significant, standing for the 5.8% of the damage to HH and 5.5% of the damage to Resources. Condusions With the final aim of creating a database of wood board manufacture, this work was focused in the identification and characterisation of one of the most important wood-based products: Medium Density Fibreboard. Special attention has been paid in the inventory analysis stage of the MDF industry. The results of the sensitive analysis showed a significant influence of both the final transport of the product and the electricity generation profile. Thus, the location of MDF process is of paramount importance, as both aspects have considerable site-dependence. Recommendations and Perspectives Research continues to be conducted to identify the environmental burdens associated to the materials of extended use. In this sense, future work can be focused on the comparison of different materials for specific applications.     

Methodology for developing gate-to-gate Life cycle inventory information

Life Cycle Assessment (LCA) methodology evaluates holistically the environmental consequences of a product system or activity, by quantifying the energy and materials used, the wastes released to the environment, and assessing the environmental impacts of those energy, materials and wastes. Despite the international focus on environmental impact and LCA, the quality of the underlying life cycle inventory data is at least as, if not more, important than the more qualitative LCA process. This work presents an option to generate gate-to-gate life cycle information of chemical substances, based on a transparent methodology of chemical engineering process design (an ab initio approach). In the broader concept of a Life Cycle Inventory (LCI), the information of each gate-to-gate module can be linked accordingly in a production chain, including the extraction of raw materials, transportation, disposal, reuse, etc. to provide a full cradle to gate evaluation. The goal of this article is to explain the methodology rather than to provide a tutorial on the techniques used. This methodology aims to help the LCA practitioner to obtain a fair and transparent estimate of LCI data when the information is not readily available from industry or literature. Results of gate-to-gate life cycle information generated using the cited methodology are presented as a case study. It has been our experience that both LCI and LCA information provide valuable means of understanding the net environmental consequence of any technology. The LCI information from this methodology can be used more directly in exploring engineering and chemistry changes to improve manufacturing processes. The LCA information can be used to set broader policy and to look at more macro improvements for the environment.     

Life cycle inventory for electricity generation in China

Background, Goal and Scope The objective of this study was to produce detailed a life cycle inventory (LCI) for the provision of 1 kWh of electricity to consumers in China in 2002 in order to identify areas of improvement in the industry. The system boundaries were processes in power stations, and the construction and operation of infrastructure were not included. The scope of this study was the consumption of fossil fuels and the emissions of air pollutants, water pollutants and solid wastes, which are listed as follows: (1) consumption of fossil fuels, including general fuels, such as raw coal, crude oil and natural gas, and the uranium used for nuclear power; (2) emissions of air pollutants from thermal power, hydropower and nuclear power plants; (3) emissions of water pollutants, including general water waste from fuel electric plants and radioactive waste fluid from nuclear power plants; (4) emissions of solid wastes, including fly ash and slag from thermal power plants and radioactive solid wastes from nuclear power plants. Methods Data were collected regarding the amount of fuel, properties of fuel and the technical parameters of the power plants. The emissions of CO₂, SO₂, NO_x, CH₄, CO, non-methane volatile organic compound (NMVOC), dust and heavy metals (As, Cd, Cr, Hg, Ni, Pb, V, Zn) from thermal power plants as well as fuel production and distribution were estimated. The emissions of CO₂ and CH₄ from hydropower plants and radioactive emissions from nuclear power plants were also investigated. Finally, the life cycle inventory for China’s electricity industry was calculated and analyzed. Results Related to 1 kWh of usable electricity in China in 2002, the consumption of coal, oil, gas and enriched uranium were 4.57E-01, 8.88E-03, 7.95E-03 and 9.03E-08 kg; the emissions of CO₂, SO₂, NO_x, CO, CH₄, NMVOC, dust, As, Cd, Cr, Hg, Ni, Pb, V, and Zn were 8.77E-01, 8.04E-03, 5.23E-03, 1.25E-03, 2.65E-03, 3.95E-04, 1.63E-02, 1.62E-06, 1.03E-08, 1.37E-07, 7.11E-08, 2.03E-07, 1.42E-06, 2.33E-06, and 1.94E-06 kg; the emissions of waste water, COD, coal fly ash, and slag were 1.31, 6.02E-05, 8.34E-02, and 1.87E-02 kg; and the emissions of inactive gas, halogen and gasoloid, tritium, non-tritium, and radioactive solid waste were 3.74E+01 Bq, 1.61E-01 Bq, 4.22E+01 Bq, 4.06E-02 Bq, and 2.68E-10 m³ respectively. Conclusions The comparison result between the LCI data of China’s electricity industry and that of Japan showed that most emission intensities of China’s electricity industry were higher than that of Japan except for NMVOC. Compared with emission intensities of the electricity industry in Japan, the emission intensities of CO₂ and Ni in China were about double; the emission intensities of NO_x, Cd, CO, Cr, Hg and SO₂ in China were more than 10 times that of Japan; and the emission intensities of CH₄, V, Pb, Zn, As and dust were more than 20 times. The reasons for such disparities were also analyzed. Recommendations and Perspectives To get better LCI for the electricity industry in China, it is important to estimate the life cycle emissions during fuel production and transportation for China. Another future improvement could be the development of LCIs for construction and operation of infrastructure such as factory buildings and dams. It would also be important to add the information about land use for hydropower.     

Life cycle analysis with ill-defined data and its application to building products

In contradiction with the flow accuracy requirement of the classical LCA model, most LCA data cannot be represented by an accurate value because they loose realism in the process. It is particularly true with building products’ data. Intervals are introduced to model such data, thus allowing LCA calculations to get rid off flow accuracy. Thus, interval calculation techniques for LCA are developed and the benefits from a replacement of classical LCA algorithms with these techniques are analyzed.     

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 inventory for electric energy system in Brazil

Goal, Scope and Background  

The goal of this paper is to present the modeling of life cycle inventory (LCI) for electric energy production and delivery in Brazil for the reference year 2000 by application of ISO 14040. Site specific data along with sector production data have been combined to construct an energy production model, which has been applied to emissions estimation. Background-data of all the inputs and outputs from the system have been inventoried as follows: gross electric energy generation, installed nameplate capacity, flooded area, losses, emissions to air / water, process waste, used fuel, efficiency and land use.     

Life cycle inventory modeling of phosphorus substitution,losses and crop uptake after land application of organic waste products

Purpose

Life cycle assessments (LCAs) that attempt to provide advice on treatment options for phosphorus (P) containing organic waste products encounter problems related to the quantification of mineral P fertilizer substitution, P loss and crop P uptake after land application. The purpose of this study was to develop a relatively easy to use life cycle inventory model, known as PLCI, that could be used to estimate these values.

Methods

A life cycle inventory model for P was developed, which estimates the effect of an application of organic waste followed by ordinary fertilizer management in the modeling period. This was compared with a simulation without the initial waste application. The difference in mineral P fertilizer application (substitution), P loss and crop P uptake was then calculated and expressed as a proportion of the amount of waste applied. As an example, the effect of an initial application of mineral fertilizer, sewage sludge and ash on two farm types was simulated. These results were applied in an LCA case study of different sewage sludge treatment options.

Results and discussion

Farm type influenced the P fertilizer substitution, loss and crop uptake factors. The application on an arable farm showed a substitution of 28 to 31%, relatively low P loss and a large spread in crop P uptake for the different P sources, compared with the pig farm. Application on a pig farm showed no mineral P substitution. For substitution, mineral fertilizer outperformed waste product fertilizer with a short modeling period, due to higher immediate P availability, which was not the case with a long period. The LCA case study showed that the P substitution factor had an influence on the environmental impact categories climate change and depletion of reserve-based abiotic resources while the P loss factor influenced freshwater eutrophication. Application of the P loss and substitution factors generated from the PLCI model resulted in higher environmental burdens and lower savings than using conventional factors.

Conclusions

The soil P status mainly affected P substitution and loss, with the fertilizer type only having a small influence when soils had a low P status. The PLCI model can facilitate more coherent and rigorous estimates of P substitution and loss to be used in LCA studies involving application of waste products on agricultural land. This is important since P substitution and loss can have an important influence on impact categories, such as freshwater eutrophication and resource depletion.

     

Life cycle assessment as a tool for improving process performance: A case study on boron products

This paper explores the use of LCA as a tool for process environmental management, thereby moving the focus from product to process oriented analysis. The emphasis is on Improvement Assessment in which the “hot spots” in the system are targeted for maximum environmental improvements. In this context, it is useful to use multiobjective optimisation which renders Valuation unnecessary. The approach is illustrated by the case study of the system processing boron ores to make five different products. The results of Inventory Analysis and Impact Assessment are presented and discussed. In Improvement Assessment, a number of improvement options are identified and evaluated, using system optimisation. It is shown that the site environmental performance can be improved over current operation by an average of 20% over the whole life cycle. Thus the study demonstrates that the optimisation approach to environmental process management may assist in identifying optimal ways to operate a process or plant from “cradle to grave”. This may help the process industries not only to comply with legislation but also provide a framework for taking a more proactive approach to environmental management leading to more sustainable industrial operations and practices.     

Life cycle inventory study of the electrical energy production in Romania

Aim, Scope and Background The paper proposes the assessment of the environmental interventions resulting from the electrical energy production in Romania, a Central East European country, using the LCA technique limited to a Life Cycle Inventory study (an LCA without the Life Cycle Impact Assessment phase). Main Features The following life cycles of the energy carriers employed in the production of the electrical energy are analysed according to their provenance: lignite (domestic) 31.2%, brown coal (domestic) 3.4%, brown coal (import) 0.4%, heavy oil (domestic, land) 4.2%, heavy oil (domestic, continental platform of the Black Sea) 0.4%, heavy oil (import) 3.6%, natural gas (domestic) 12.4%, natural gas (import) 6.1%, hydropower 27.8%, and nuclear energy 10.5% from the total of the electrical energy produced in Romania. The unit processes of the life cycles of these energy carriers are aggregated in two main stages: Pre-combustion (extraction, processing, transport and achievement of infrastructure) and Combustion (the production of electricity). The functional unit of the study is represented by 1 kwh. The spatial limits of the analysed system are extended as far as CIS countries for coal, Western Siberia (Russian Federation) for natural gas and the OPEC countries for oil. The temporal limits are included in the year 2000. Results and Discussion The LCI study enabled us to quantify the interventions on the environment, which result from the electricity production in Romania, the independent use of different energy carriers and the different life cycle stages of the system. The use of the LCA technique in a prospective way shows the reduction of these interventions that could be achieved through the adoption of specific scenarios for the development of electrical energy production in the country. Conclusions The main findings of this Life Cycle Inventory study, the first for Romania, are: the emissions of pollutant substances are prevailing in the combustion stage; for different energy carriers, the magnitude of environmental interventions decrease in the following order: coal, oil, natural gas, hydropower and nuclear energy. By comparison with other countries, the environment is more affected by the production of electricity in the case of Romania and only the promotion of alternative, renewable resources such as hydropower could substantially improve these interventions. Recommendations and Perspectives Some important interactions with the environment, like land use or the risks of the nuclear energy, are not taken into consideration in the study because of the lack of particular data for Romania. We would like to continue the investigation in order to surpass the limits of the study, on the one hand by collecting data concerning the risk of nuclear power or land use at the national level for different energy carriers or, on the other hand, by taking into account some other renewable resources like wind or solar energy.     

Life cycle inventory modelling of land use induced by crop consumption

Background, aims and scope  

Most life cycle inventory data for crops do not include the ultimate (marginal) land use induced by crop consumption. The aims of this study were to present, document and discuss a method which can solve this problem and, furthermore, to present concrete examples for wheat consumption in Brazil, China, Denmark and the USA. A global scope is applied and the simulated adaptation to increased wheat demand corresponds to a long-term temporal scope under present market conditions with present technology.     

Life cycle inventory modelling of land use induced by crop consumption

Background, Aims and Scope  

The actual land use consequences of crop consumption are not very well reflected in existing life cycle inventories. The state of the art is that such inventories typically include data from crop production in the country in which the crop is produced, and consequently the inventories do not necessarily consider the land ultimately affected in the systems being studied. The aims of this study are to analyse the mechanisms influencing the long-term land use consequences of changes in crop demand and to propose a methodological framework for identifying these consequences within a global scope.     

Life cycle assessment of automotive fuels: critical analysis and recommendations on the emissions inventory in the tank to wheels stage

Purpose  

As new alternative automotive fuels are being developed, life cycle assessment (LCA) is being used to assess the sustainability of these new options. A fuel LCA is commonly referred as a “Well To Wheels” analysis and calculates the environmental impacts of producing the fuel (the “Well To Tank” stage) and using it to move a car (the “Tank To Wheels” stage, TTW). The TTW environmental impacts are the main topic of this article.     

Life cycle analysis of algae biodiesel

Background, aim, and scope  

Algae biomass has great promise as a sustainable alternative to conventional transportation fuels. In this study, a well-to-pump life cycle assessment (LCA) was performed to investigate the overall sustainability and net energy balance of an algal biodiesel process. The goal of this LCA was to provide baseline information for the algae biodiesel process.     

Life cycle assessment of products from agro-based companies in Uganda

The International Journal of Life Cycle Assessment - Despite the fact that life cycle assessment (LCA) is a very vital tool, it has not been used in Uganda most likely because very little is known...