The assessment of biorefineries generally encounters as a difficulty, that so far there is no unified classification system. The most widely quoted definition of ‘biorefinery’ has been published by the International Energy Agency (IEA) Task 42. ‘Biorefinery is sustainable processing of biomass into a spectrum of marketable products (food, feed, materials, and chemicals) and energy (fuels, power, heat).’ In the same report, a generic classification of biorefinery systems is proposed based on four main features: platforms, products, feedstocks, and conversion processes. Most LCA studies on biorefineries consider or compare products or feedstocks, thus the other classification features such as platform and process appear only in the background. Information about platform and process only gets a closer look when systems are optimized, e. g. to use the same platform for multiple products, to optimize and reduce processing steps, or to avoid energy­intensive processes. The focus of LCA studies is on the products of biorefineries, which is not surprising, as LCA is always focused along the life cycle of its functional unit. This is an advantage on one hand, as it makes comparisons with other process routes for the same product quite easy. On the other hand, it is a shortcoming because the possible specific advantage of a biorefinery as a networking production system is difficult to account for. Still, in the following section a structure following specific products of biorefineries will be applied, while possible shortcomings by the holistic approaches of biorefineries will be discussed later.