7. Liquid and Gaseous Biofuels for the Transport Sector

In regards to a demand-oriented biofuel supply for the transport sector, this chapter considers the most relevant technologies and concepts for the production and supply of the most important liquid and gaseous biofuels and their current status quo. The limits of and opportunities presented by flexible biofuel production are considered. It has to be noted that flexible or part load operation of biofuel plants is not common. This also applies for most engineering plants in the chemical industry. Today biofuel plants are most commonly constructed as multiproduct plants such as bio refineries. Since the most inflexible step has an effect on the general system flexibility, intermediate storage, raw materials and various products are utilized in order to increase the system flexibility. Flexible management (i) of raw material and other input streams such as auxiliaries (reaction media, catalysts) and (ii) of plant operation in terms of main and by-products including the provision of products with high flexibility in application, is much more common than part load. In the article these opportunities are discussed for existing and new biofuel concepts. Furthermore, general issues of costing and environmental impact are considered.