High pressure biomass conversion processes for biofuel and chemicals production

N. COTABARREN; G. SOTO; P. HEGEL; S. PEREDA

Concepción

Congreso; 3rd Iberoamerican Congress on Biorefineries (CIAB); 2015

Universidad de Concepción. Chile

The emerging high pressure processing techniques in the last years shows it is an interesting alternative to transform the concept of chemical biorefinery plants regarding more compact, safe, energy-efficient, environment-friendly sustainable processes. The continuous non-catalytic supercritical alcohol transesterification technology, for instance, is an interesting high pressure process useful to obtain biodiesel and acylglycerol derivatives from non-edible vegetable oil, microalgae, waste cooking oils, and oil by-products. This technology has several advantages including high production yields and environmental friendliness. Oleaginous microalgae have been proposed as sustainable alternative to produce biodiesel in order to replace the vegetable oil derived from oilseed crops. Different freshwater microalgae have been recognized as a promising oil feedstock, due to its capacity to accumulate lipids. Particularly, recent studies pointed out the potential of N. oleoabundans, cultured in sea water or in anaerobically digested dairy manure, to produce triglycerides with high content of monounsaturated fatty acids [1].Second generation oil-based biorefineries are aimed to enrich any residue with oil content. For example, the great increase of worldwide production of soybean and sunflower oil, impacted not only in the oil market but also in the oil refining by-products (phospholipids sludge and distillates of the deodorizer), which prices are rapidly changing, and because of the high production volume of vegetable oils this by-products are becoming a waste with disposal-associated problems. An alternative sustainable technology for this by-product is the direct alcoholysis of phospholipids and vegetable oil (triglycerides) occluded in the wet gum using high pressure supercritical ethanol to produce fatty acids ethyl esters (FAEEs) and derivatives [2]. On the other hand, acylglycerols (ACs) are high added-value products derived from vegetable oil. They are common food emulsifiers and surface active agents in many industrial cleaning products. ACs can be economically produced in biodiesel processing plants, carrying out an incomplete transesterification of vegetable oil. Moreover, the purification of monoglycerides (MG) from a mixture of biodiesel can be carried out with pure CO2 as a green solvent. Additionally, high purity fatty esters free of tinctures can be obtained also in the CO2 separation process [3].In this presentation, sustainable technologies for, microalgae, residues processing and vegetable oil recycling will be discussed. Moreover, also a high pressure technology for fractionation of fatty esters and MG up to high purity will be presented. Integration of the discussed technologies may contribute to pave the way towards oil-based second generation biorefinery development.[1] C.A. Popovich, C. Damiani, D. Constenla, A.M. Martínez, H. Freije, M. Giovanardi, S. Pancaldi, P.I. Leonardi. (2012) Neochloris oleoabundans grown in enriched natural seawater for biodiesel feedstock: Evaluation of its growth and biochemical composition, Bioresource Technology 114, 287-293.[2] G. Soto, A. Velez, P. Hegel, G. Mabe, S. Pereda. (2013) Fatty acids recovery from vegetable oil wet sludge by supercritical alcoholisis. (79), 62-66.[3] G. Soto, P. Hegel, S. Pereda, (2014). Supercritical production and fractionation of fatty acid esters and acylglycerols. J. Supercrit. Fluids 93, 74-81.