With reference to ISO standards, the definitions commonly used by professionals on an international level are provided in alphabetical order. Round brackets indicate the English terminology and, where applicable, the reference to the regulatory paragraph. The literal translation is in italics.
Composting
(Composting): Biological degradation of wet waste with high organic content; leads to the production of compost (stabilized organic material for agricultural and horticultural use based on its composition).
CO2-equivalent Concentration
(CO2-equivalent): synthetically expresses the greenhouse gases' capacity to cause the greenhouse effect; it is obtained by converting the concentration of each gas that can cause a greenhouse effect into the concentration of CO2 that would provide an equal contribution to that effect (different gases contribute differently to the greenhouse effect at the same concentration). The conversion is done through the GWP or Global Warming Potential, available for different time periods (50, 100, and 500 years).
System Boundaries
(System boundary - ISO 14040, par 3.17): interface between the specific system being studied and the environment or other systems produced.
Comparative Assertion between Equivalent Systems
(Comparative assertion - ISO 14040, par. 3.2): Environmental statement regarding the superiority or equivalence of a product compared to a competing product with the same function; a term introduced by ISO 14040 to indicate how, through the comparison in terms of Life Cycle Assessment of production systems with the same function, it is possible to assert which one has a better environmental performance.
Co-Product
(Co-product - ISO 14041, par. 3.2): Each of the 2 or more products derived from the same unit process; in this context, a byproduct or waste of the same industrial process with market value and subject to allocation rules.
Eco-Balance
(Eco-balance): in this context, an energy and environmental analysis applied to a single link in the production chain, or the simplest element of which an LCA (Life Cycle Assessment) is composed.
Eco-Profile
(Eco-profile): is a life cycle analysis interrupted at the material flows leaving the facility ("from cradle to gate").
Efficiency
In general, efficiency measures the ability of a system to generate a useful function compared to the cost incurred to achieve it. Energy efficiency is the ratio of energy in products and energy expended (input energy + energy in raw materials); exergy efficiency is the ratio of the exergy of useful products to the input exergy.
Gross Energy
(Gross energy): It is the total energy that belongs to a production system and consists of the sum of energies corresponding to all the operations that made it possible, starting from the extraction of raw materials. Gross energy can be divided into at least 5 parts: direct energy (direct energy or energy content of fuel), feedstock energy, production and transportation energy of fuels, energy of the transports used, and biomass energy.
Direct or Process Energy
(Direct energy or process energy - ISO 14041, par. 3.9): energy required to power a unit process or an apparatus within the process, excluding the production and distribution of the energy itself; it is the energy directly consumed in operations strictly related to the process being studied; it coincides with the energy content of the energy source used.
Feedstock Energy
(Feedstock energy - ISO 14041, par. 3.5): energy content of the raw materials entering the production system, not usable as an energy source, expressed in terms of higher or lower calorific value; it is the energy contained in materials entering the process that could potentially be used as fuels. Their contribution in energy terms can be expressed through the higher calorific value; gas and oil used in the petrochemical industry and wood used in the paper industry are clear examples.
Production & Delivery Energy of Fuels
(Production & Delivery energy): It is the energy involved in the extraction, processing, and transportation of primary energy sources later made available to the user in the form of direct energy. It is part of the indirect energy.
Indirect Energy
(Indirect energy): It consists of the sum of the energy for the production and transportation of fuels with the energy necessary to make the materials entering the process available.
Exergy
(Exergy): Generally indicated by the letter B, it is defined as the portion of an energy resource usable in a thermodynamically reversible process. In practice, it is the concept that allows to evaluate the quality of the spent energy, or its ability to cause changes.
Following Part 3
