Natale Palmeri

Feedstocks for biodiesel production

Abstract: Globally dominating feedstocks for biodiesel production nowadays are mainly rapeseed, soybean, sunflower and palm oils; animal fats (tallow) and recycled frying oils are minor contributors. This chapter describes the main characteristics of the major and minor first-generation foodstocks for biodiesel production and the short- to medium-term prospects of second-generation, non-edible feedstocks (in particular Jatropha and algae) and various highly acidic, low-quality oils for the same purpose. Biodiesel outlooks are differing geographically as a result of the prevailing agronomic and climatic conditions. Important developments can be observed in various parts of the world.

Solid-state luminescence switching of platinum(II) dithiooxamide complexes in the presence of hydrogen halide and amine gases

In the solid state, a non-luminescent platinum(ii) dithiooxamide species adsorbs gaseous HCl, yielding a tight ion pair species which exhibits photoluminescence; the process is quantitatively reversed on heating or by exposing the sample to ammonia vapors.

Industrial process technology for biodiesel production

This chapter describes the main characteristics of various biodiesel process technologies (batch, semi-continuous, continuous flow; base- and acid-catalysed; plant size from miniplants at community level to large-scale plants; plant modularity; feedstock quality control, etc.) in terms of critical success factors. Plant technology is discussed in relation to feedstock supply. Factors affecting biodiesel manufacturing technology are outlined as well as minimum conditions for economically viable biodiesel plants. Several proprietary transesterification processing technologies are described. Selected biodiesel producers worldwide (Europe, USA, South-East Asia, South America), ranging from community-based production units to highly integrated biodiesel plants, are considered. Biodiesel blending techniques are evaluated.

Sustainability and use of biodiesel

One of the energy policy goals is production and use of sustainable biodiesel. There is no general consensus on the use of an important analytical tool (life cycle assessment) as to inclusion of the effects of land use (change). Biodiesel fuel properties were evaluated in comparison to petrodiesel, in particular as to operability in terms of cold-temperature performance, storage stability and engine exhaust emissions. Not all biodiesel fuels are created equal. Biodiesel economics have been evaluated in particular in relation to feedstock and manufacturing costs and competitiveness. Biodiesel use and market prospects were detailed critically for the EU, the US and emerging economies (BRIC, South-East Asia, Argentina).

Vegetable oil formulations for utilisation as biofuels

Although direct use of high-viscosity straight vegetable oils in standard modern diesel engines has been reported, the practice of using such non-regulated fuels is generally not recommended as short- and long-term problems do result. Engine compatibility for vegetable oils and animal fats may be enhanced chemically (by derivatisation, pyrolysis/gasification, ozonation) or physically (by dilution, blending, microemulsification). Fuel properties of oils and fats are outlined.

8 – Biodiesel catalysis

: This chapter considers the various aspects of homogeneous and heterogeneous alkaline and acid catalysis of high-quality, low free fatty acids (FFAs) containing feedstocks for transformation of vegetable oils and animal fats into fatty acid alkyl esters (biodiesel). The influence of the most important operating variables affecting fatty acid ester yield are considered. In particular, the effects of FFAs and water on alcoholysis have been investigated. Mechanisms of alkali- and acid-catalysed reactions are described. Acid catalysis is indicated as being essential for transesterification of notoriously difficult triglyceride feedstocks with high FFA and water contents.

Valorisation of the glycerol by-product from biodiesel production

The economic viability of the transesterification process of triglycerides is enhanced by valorisation of the main by-product, glycerol. Glycerol quality depends on the biodiesel process characteristics. This chapter describes new high-volume products and applications based on direct use of crude glycerol as a platform substrate, cost-effective purification processes, and innovative commercial use of glycerol by (bio)catalytic conversion into commodity chemicals by selective oxidation, hydrogenolysis and dehydration, pyrolysis and gasification, steam reforming, thermal reduction, selective (trans)esterification and etherification, oligomerisation and polymerisation, chlorination and carboxylation.

Emerging new energy crops for biodiesel production

Selection criteria for potential energy crops for biodiesel application include chemical structure and quality parameters of the oil and factors related to genotype, ecology, cultivation, maturation, oil extraction performance, etc., of the plant species. Target compositions should ensure desirable cold flow, ignition, oxidative stability and emission characteristics of biodiesel. The agronomic challenge is to create such affordable oils, preferably complying with food applications and creating value across the food and fuel chains. New feedstock opportunities vary significantly as to their potential impact in the market in terms of volume and timing to commercialisation. A limited number of developments will add to the global feedstock supply for biodiesel.

Oleochemical sources: basic science, processing and applications of oils

Natural lipid biosynthesis is regulated by enzymatic activity and leads to a broad variety of oils in seeds and fruits in which a restricted subset of fatty acid compositions predominates and accounts for the traditional use of oils and fats in food and oleochemical applications. Both genetic and environmental factors affect triacylglycerol (TAG) biochemistry. Manipulation of fatty acid and TAG synthesis for the purpose of usability for both nutritional and industrial applications by means of natural breeding methods and genetic engineering techniques rely on detailed knowledge of biochemical pathways. The features of various oil recovery and refining techniques are outlined and the applications of unusual fatty acids are described.

Evolution of biodiesel and alternative diesel fuels

First-generation liquid biofuels such as biodiesel (via transesterification) and bioethanol suffer from various limitations, foremost limited access to foodstocks. Second-generation biodiesel and renewable diesel substitutes require alternative feedstocks, which can be produced without interference with edible agricultural crops. Development of these energy crops in commercial quantities still requires at least five years. Breakthrough catalyst technologies are already available. Technological developments based on hydroprocessing have led to commercialisation of second-generation alkane-based renewable diesels based on the same feedstocks as biodiesel, namely vegetable oils and animal fats. Next-generation renewable diesels will be biomass-based without the present supply limitations. Gas-to-liquid (GTL) and biomass-to-liquid (BTL) technologies are still under development.