Bartosz Rozmystowicz, Paivi Maki-Arvela and Dmitry Yu. Murzin

6.1 Introduction

Constant decrease of fossil fuels reserves creates a great need for development of the new technologies for production of liquid transportation fuels based on renewable sources. World crude oil reserves, according to OPEC [1], are at the level of 1,337.2 billion barrels. In year 2010 the daily world consumption reached

86.6 million barrels per day (mb/d) [2] with the forecast of increase by 1.4 and

1.6 mb/d in the following 2 years [2]. Even with an assumption that the world fuel consumption will be maintained at the same level, reserves of oil should run out in approximately 40 years. This threat of oil pools depletion leads to an increase of interest in biofuels, both by governments and industries.

Recently in numerous countries legislation measures were taken to increase biofuels share in transportation fuels. European Union will increase the usage of biofuels both in gasoline and diesel to 10% by 2020 [3]. Analogous regulations were proposed in China, Brazil, India, and USA which indicates that biofuels will have significant share of liquid transportation fuels market.

Renewable fuels can be named as first or second generation biofuels depending on the origin. The first-generation biofuels are made mainly from crops. To produce bioethanol cereals, maize or sugar beet is used, whereas biodiesel feed­stock consists of canola, soybean, or palm oil. There is a great concern that the production of those fuels in large scale could in a significant way decrease food cropland. Therefore, the second generation of biofuels was introduced using non-food crops source such us lignocellulosic residues, tall oil, or algae. Another advantage of those fuels is lower emissions of CO2 per unit of energy content

B. Rozmystowicz • P. Maki-Arvela • D. Yu. Murzin (H)

Laboratory of Industrial Chemistry and Reaction Engineering, Process Chemistry Centre, Abo Akademi University, 20500 Turku/Abo, Finland e-mail: dmurzin@abo. fi

C. Baskar et al. (eds.), Biomass Conversion,

DOI: 10.1007/978-3-642-28418-2_6, © Springer-Verlag Berlin Heidelberg 2012

(Fig. 6.1) by LCA WTW assessment (life cycle assessment, well-to wheel), which is the product life cycle starting from extraction to waste disposal [4, 5].

While in first — and second-generation bioethanol there are no differences in composition of the fuel, significant differences could be observed in the case of biodiesel. Originally biodiesel was the name connected to fatty acids methyl ester (FAME), but recently new technologies emerged for production of diesel fuels that originates from biomass. Deoxygenation of fatty acids is a process involving hydrodeoxygenation (HDO) or decarboxylation/decarbonylation of carboxylic group that leads to formation of diesel-like hydrocarbons (Green diesel). Process of HDO is already applied on industrial scale by Neste Oil (NExBTL oil). There are three units already operating (Singapore and two in Finland) and one in construction (Rotterdam, which should be ready in the end of the year 2011) with combined capacity of around 2 million tons per year [6]. In this process fatty acids are converted to aliphatic hydrocarbons, which is advantageous compared to transesterification method, where products contain significant amount of oxygen.

The other option besides HDO is decarboxylation/decarbonylation. Pioneering work was performed recently with participation of the authors [7-9]. It was found that it is possible to remove carboxylic group using heterogeneous catalysts, with less hydrogen consumption than in HDO process.

In this chapter comparison of different routes of deoxygenation will be described as well as recent research in this field.