生命周期评价案例1

Background of the study
The usuage of renewable resources [see also “Renewable Resources”, glossary] will become more important in future. For being competitive, products made by refining these renewable resources have to be technically and economically equal to products made from petrochemical raw materials. In addition, they have to be more sustainable.
Credit items Within the study it was considered that intermediates are not produced in any affiliated location and that there is no usage of the waste heat. Credits were only considered for the production of acrylic acid because of the good database. There was also no bonus passed to the inventory’s credit for the
How was the Inventory Analysis drawn up?
In the following paragraph the details of drawing up an inventory analysis should be described more precisely. The time scope and the demands on the amounts of data could be demonstrated by it. The structure of the system was refined because of the fact that two different ways of manufacturing are compared to each other and those methods consist of varying steps. This procedure is explained in the following. Fine Structure of the System The system boundaries have been divided into the sectors “Linseed Oil Epoxide” and “Petrochemical coating binder” for drawing a comparison. Additional subdivisions depend on the logical order of the value-added chain of each system. The inventory section “Linseed Oil Epoxide” was subdivided into the sub-processes shown in Figure 3 according to the chain of economic value added.
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Fig. 1: System of Coating Binders
Other predefinitions must be determined for selecting the inventory boundaries. They are described subsequently.
Cut-off Criteria (Limits of detail) No material flows were usually cut off in the presented study. All flows required for the interpretation have been observed and evaluated from entering to leaving the system boundaries if the database was sufficient.
Allocation The total process energy was allocated according to the proportion of the particular product in the total production. The emissions and disposals that result from the manufacturing were treated as well. They were prorated according to their share in the entire otilization of coupling products, but the possibility was pointed out.
Geographical and chronological reference The considerations refer to the political borders of the Federal Republic of Germany. If substances were provided in other countries (e. g. mineral oil) the country of origin has been chosen as reference weighed according to the particular market share of the substance in Germany. The year 1999 was selected as reference year for the views.
Life Cycle Assessment – Example 1
Why has this study been selected as an example?
The requirements of the Life Cycle Assessment method provided by the ISO/DIN 14040 et sqq. standards are sometimes difficult to understand. The study “Life Cycle Assessment of selected raw materials for paints: a comparison between vehicles based on renewable and petrochemical raw materials” was chosen to make the abstract statements of this norm more clearly. The study was carried out according to the ISO standard. Differently from this, the parts “Life Cycle Impact Assessment” as well as “critical review” were not included into the balance. Nevertheless, the necessary steps the Life Cycle Assessment method (without Impact Assessment) can be conceived within this example.
Fig. 1: parquet surface, sealed with UV-hardening varnishes
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How were the general conditions defined?
The Aim of this Study The aim of the study was a holistic data entry of environmental impacts caused by the production of the coating binder linseed oil epoxide (Leinölepoxid, ELO) on the basis of the renewable material linseed oil. A petrochemical coating binder consisting of a mixture (50:50) of tripropylene glycol diacrylat (TPGDA) and bisphenol-A-diglycidetheracrylat (DGEABA) has been taken as reference.
The System boundaries of the Investigation According to the aim of a holistic examination all up- and downstream processes were considered. That means that the non-facility scopes of supplying raw materials and energy were also included in the examination. The material and energy flows emerging within the system boundaries were observed and inventoried usually from their withdrawal or to their releasing into the environment respectively. The environment serves as source (e. g. the removal of crude oil from the deposits) or as drain (e. g. CO2-emissions into the atmosphere) for material flows. The system boundary is defined as the gate of the manufacturer of the processible coating binder. The system boundary “gate” could be chosen because technical equivalence was assumed for the different products. That means there is no difference in usuage, disposal etc..