Important Terms from A to Z
Life Cycle Assessment (LCA)
Life cycle assessment (LCA) is the methodical analysis of the environmental effects of products in particular (but also of processes and services). It usually takes the entire lifecycle into account, from production and use through to disposal, as well as associated upstream and downstream processes (e.g. extraction of raw materials or manufacturing intermediate products). So the LCA is a process to analyze and evaluate products or processes in terms of their environmental impact. Calculations using GEMIS (Global Emissions Model for Integrated Systems) are considered the standard for contemporary life cycle assessments. GEMIS is a free public domain life-cycle and material flow analysis model, which also includes an extensive database on energy carriers, materials, and energy and material processes.
The life cycle assessment of fuels should consider the processes of material extraction and raw materials processing on the one hand, and environmental pollution from combustion on the other.
The easiest to evaluate is the environmental impact of combustion. Carbon dioxide emissions are calculated purely stoichiometrically from the chemistry of the fuel: 1 liter of diesel fuel produces about 2.6 kilograms of carbon dioxide during combustion; 1 liter of gasoline 2.3 kilograms of carbon dioxide. Other emissions arise primarily from the fuel quality (e.g. the sulfur content) or the parameters of the combustion process (in particular the production of nitrogen oxides).
The evaluation of fuels with regard to their upstream environmental impact is more difficult. Especially with biofuels to generate motion, this calculation is often only possible using certain assumptions. For instance, the previous use of the land on which the bioenergy is produced plays a major role for the LCA. This is known as indirect land use change (ILUC). To set an example: plants for fuel are being grown on land that was previously used for other crops. If new land is then sought for this, it may replace forest or fallow land. When converting these natural habitats to arable land, greenhouse gas emissions arise that should logically be attributed to the biofuel.
Nor is it easy to assess the process energy needed to produce this fuel. For example, the production of biodiesel results in glycerin as a by-product. As long as this substance finds a use as a raw material on the market, the biodiesel production can be credited with the amount of energy that is usually required for the production of glycerin. But as soon as the market can no longer absorb the glycerin, this credit must be eliminated. So, the life cycle assessment does not depend solely on scientific and technical aspects.
The LCA in accordance with ISO 14040 and 14044 is an international standardizing procedure for evaluating and assessing environmental impact from "cradle to grave.” DIN EN ISO 14040 (“Environmental Management - Life Cycle Assessment - Principles and Framework”) establishes principles and conditions for the creation of product lifecycle assessments. DIN EN ISO 14044 (“Environmental Management - Life Cycle Assessment - Requirements and Guidelines”) contains details relating to requirements and instructions. But when carrying out LCAs at companies, not only one method is prescribed, but rather countless different methods can be used, e.g. ABC analysis, greenhouse gas footprint, the Sustainable Process Index, the CML method, UBA impact indicators, the Eco-Indicator 99 and many more. Many of the methods involve different indicators.
The life cycle assessments published by different protagonists for products, processes and services, and in this connection also for biofuels, for example, vary accordingly. But in order to standardize the assessment of biofuels at European level, standard values have been defined for biofuels produced in Europe, at least for greenhouse gas emissions. To comply with the Fuel Quality Directive (Directive 2009/30/EC), biofuels must achieve greenhouse gas emission reductions of currently at least 35% compared to fossil fuels. This value increases to 50% in 2017.
At the Marquard & Bahls Group, environmental issues are an integral part of the HSSE and sustainability management system, with the aim of minimizing direct and indirect impacts on the environment, and improving the life-cycle assessments of our services. Please refer to Marquard & Bahls’ annual Sustainability Report for detailed figures (cf. News & Info > Publications & Downloads > Sustainability Report).
Status: December 2015
All information subject to change. Errors and omissions excepted.