Environmental Engineering Reference
In-Depth Information
product, or service and includes all energy and raw material as
inputs
and the environmental
wastes as
outputs
. Conducting an LCA requires the identification and assessment of all inputs and
outputs in the process including packaging, transportation, and distribution. The process is time-
consuming and requires considerable amounts of data that sometimes is difficult to obtain; there-
fore, assumptions or simplifications are made in many cases.
LCAs do not incorporate into the analysis important environmental effects such as biodi-
versity, the landscape, and the local impact of water use (Foster et al., 2006). As mentioned,
monetary issues are also not included in an LCA; therefore, other tools are used to account for
cost and performance to make the best decision about a product or a process (Environmental
Protection Agency [EPA], 2006).
To illustrate the intricacies of an LCA, the production of canned green beans will be used
as an example. The basic process for production of canned green beans consists of filling
metal cans with clean, sorted, and trimmed green beans that are then covered with brine,
closed, commercially sterilized, labeled, and packed in secondary containers. These contain-
ers are then palleted and sent to distributions centers. So in a first layer of analysis, the materi-
als needed to make canned green beans are green beans, metal cans and lids, salt, water,
cardboard boxes, pallets, and miscellaneous items such as glue, plastic films, and labels.
Energy requirements include electricity to run the canning plant and natural gas for steam
production. Effluents and emissions primarily include wastewater, solid waste from the sorting
and cleaning, and air emissions.
If the process just described is observed with a magnifying glass then energy, materials, and
wastes produced at every single step of the process needs to be included in the analysis. This would
also include the impacts involved during production of green beans in the fields, construction of
cans, and the production of labels, cardboard boxes, and plastic films, just to mention a few.
Depending on the depth of the analysis, LCAs can be classified into three different orders.
The simplest is one in which only materials and transport are included is called a
first-order
approach
to LCA and it is hardly ever used. In a
second-order approach
, all environmental
impacts are considered, including production of electricity, fuel for machinery and transport,
chemical additives, pesticides, fertilizers, herbicides, ingredients, and water. In a
third-order
approach
, all capital goods are included in the analysis. For the canned green beans example,
it would include such things as the impact of manufacturing farming equipment, trucks, the
canning plant, the pulp and paper mill, and equipment for salt mining operations. When
including capital goods in the analysis, a first-order approach is generally followed for their
evaluation (Goedkoop et al., 2008).
Figure 4.1 depicts a flowchart with the ramifications of conducting a second-order LCA for
the canned green beans example. This LCA includes all steps from agricultural production
until the product reaches the consumer and is called a
cradle-to-gate
analysis. If preparation
of the food at home is incorporated in the LCA, it turns into a
farm-to-fork
analysis. When
disposal of wastes after consumption (e.g., packaging, food scraps, etc.) is included, then the
LCA is a
cradle-to-grave
analysis.
It is understandable that for companies with a large number of products in their portfolio
the complexity of conducting this kind of analysis for every single product may become labor
intensive.
Applications of LCAs
At this time, there are no requirements for companies to provide consumers with informa-
tion on the environmental impact of products or services. However, pressure is increasing
from consumers and nongovernmental organizations about the impact of products and
