Life cycle assessment energy inputs

For a full life cycle assessment, the basic principle is that each material and energy input into the system should be traced back to natural resources obtained from the environment, or to releases into the environment. These are termed elementary flows , and they represent inputs into or outputs from the system being analysed. In an analysis of this type, it may be relatively straightforward to assign a material value to a flow of (for example) water effluent into the environment, but what may be less certain is the environmental impact of such a flow in a quantitative sense. 

In the previous chapters, thermodynamic analysis is used to improve processes. However, as pointed out in Chapter 9 (Energy Conversion), the exergy analysis did not make any distinction between the combustion of coal and natural gas and, as a result, could not make any statements regarding toxicity or environmental impact of exploration, production and use of the two fuels. A technique that can do this is LCA. What exactly is life cycle analysis In ISO 14040 [1], life cycle analysis (or life cycle assessment) is defined as "the compilation and evaluation of the inputs, outputs and potential environmental impacts of a product throughout its life cycle."... 

Next, Cornelissen extended the LCA study to include the effect of depletion of natural resources making use of ELCA, the exergetic life cycle assessment. In this analysis a full mass and energy balance was made, that is, a first law analysis. Exergy values for all mass and energy streams were included in accordance with the Tables 6.1, 6.2, 6.3, 7.1, 7.2, 7.3 and 7.4 in Chapters 6 and 7. This analysis clearly showed where work was available in inputs and outputs and where it was lost. He could show that the cup scored less favorable than the mug in terms of depletion of natural resources (817 MJ vs. 442 MJ). 

The total energy efficiency of the plant, which is determined by the total available output energy and total input energy, reaches 72.6%. These heat balance data are available for LCA (life-cycle assessment). 

Pandey, K. K., Pragya, N., Sahoo, P. K. (2011). Life cycle assessment of small-scale high-input Jatropha biodiesel production in India. Applied Energy, 88, 4831—4839. 

Compared with conventional diesel refining process, GTL diesel offers significant environmental advantages such as less carbon emissions and improvement of air quality with the total absence of sulfur in the fuel. However, the GTL technology often requires intensive energy and resources input. This paper applies Life cycle assessment (LCA) method to quantify the environmental impacts of gas-to-liquid fuel processes. LCA is a tool for the analysis of environmental impacts of a product or a system, taking into... 

The life cycle inventory is a quantification of relevant energy and material inputs and environmental release data associated with the production of cotton fixrm cradle-to-gate (fiber) and manufacturing from gate-to-gate (fabric). The associated life cycle assessment models the environmental impact of representative cotton apparel from the field through to consumer care, use and disposal. 

Life Cycle Assessment is a methodology to assess the environmental impacts of a product, process or service. The International Organization for Standardization s (ISO) defines Life Cycle Assessment as A systematic set of procedures for compiling and examining the inputs and outputs of materials and energy and the associated environmental impacts directly attributable to the functioning of a product or service throughout its life cycle . 

Life cycle assessment is a methodology to assess the environmental impacts of a product, process, or service. ISO 14040 and 14044 are international standards for developing LCA, which has four steps that include definition of goal or scope, inventory of relevant material and energy inputs and relevant environmental outputs, evaluation of environmental impacts per functional unit, and interpretation of results. 

So far, there has been limited life cycle assessment of nanoparticles. Examples include carbonaceous nanoparticles and Ti02 nanoparticles. These assessments show that production of such particles requires relatively large inputs of energy and materials, if compared with larger sized particles [35-39]. For instance, 1 kg Ti02... 

Determining the impact assessment requires classification of each impact into one of these categories, characterization of the impact to establish some kind of relationship between the energy or materials input/output and a corresponding natural resource/human health/ecological impact, and finally the evaluation of the actual environmental effects. Many life cycle analyses admit that this last phase involves social, political, ethical, administrative, and financial judgments and that the quantitative analyses obtained in the characterization phase are only instruments by which to justify policy. A truly scientific life cycle analysis would end at the characterization phase, as many of the decisions made beyond that point are qualitative and subjective in nature. 

CBA, cost-benefit analysis DMC, direct material consumption DMI. direct material input EF. ecological footprint EIA, environmental impact assessment EMS, environmental management system En. energy analysis lOA, input-output analysis LCA, lifecycle assessment LCC. life cycle costing MFA, material flow accounting MIPS material intensity per unit service RA, risk assessment SEA. strategic environmental assessment SEEA system of economic and environmental accounts SFA, substance flow analysis TMR. total material requirement. 

Most LCAs are performed only xmtil Step 2, since impact assessment and interpretation involve many more qualitative assumptions. In this case, LCA are called life cycle inventories (LCIs). This latter is a tool required to estimate the direct and indirect inputs of each step of a biofuel pathway. The results are the use of resources (eg, energy consumption) and the environmental emissions (eg, CO2, sulfur oxides, nitrogen oxides). LCIs permit the assessment of impact categories, such as climate change, photooxidant formation, acidification, eutrophication, ecotoxicity and human toxicity, and the depletion of biotic and abiotic resources. These factors of the LCI will be converted into environmental damages. Various indicators can be derived from these mechanisms at intermediate levels (midpoints) or damage levels (endpoints) after normalization, often weighting approaches. 

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