Chemisch-analytische Charakterisierung technischen tierischen Fettes aus einer Tierkörperbeseitigungsanstalt

Aims and Scope

German rendering plants produce 300,000 tons of animal fat per year. Until recently, these raw products have been in wide use as nutritional additive for cattle and other animals fodder but now they have been banned due to their assumed role in BSE infection. Therefore, alternative fields of usage are required. In this context the Deutsche Bundesstiftung Umwelt (DBU) is sponsoring a joint research project which deals with the production and testing of cooling lubricants based on animal fat esters.

Methods

In a first step, characteristics and quality of the animal fat were analyzed and monitored for a whole year in order to identify e.g. seasonal variations. The investigations covered the following fat specific and trace analytical parameters: total contamination, sulfates ash, water content, peroxide number, iodine value, kinematical viscosity, neutralisation number (free fatty acids), fatty acid spectra, elements / heavy metals (Al, B, Ca, Cd, Cr, Cu, Fe, K, Mo, Mn, Na, Ni, P, Pb, S, Sn, V, W and Zn), polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

Results

Valuable hints on the design of the technical process of fatty acid methylesters production were gained by regarding the fat specific parameters. For example, filtration and dewatering of the fats proved necessary. Small variations of iodine value, viscosity and fatty acid spectrum pointed at a quite constant composition of the raw material in the course of the year. Clues to the degree of hydrolysis and decay of the fat were given by the share of free fatty acids. The saturated fatty acids, most interesting for the production of the cooling lubricants, were present in the fatty acid spectra in the rage of 36.4% to 54.6%. Trace analytical investigations concerning inorganic and organic pollutants proved a low basic contamination of the technical animal fats.

Outlook

Next step will be to present the pilot plant for the production of the cooling lubricants and further analytical results in context with the production process.     

From waste to value-added products: A review of opportunities for fish waste valorization

The fishing industry is responsible for generating large amounts of organic waste rich in compounds of commercial interest. This review aimed to present the state of the art about the possibilities of using solid waste to obtain value-added products. Skins, fins, and scales have been used to obtain gelatin and collagen, a promising compound for use as an additive in yogurts and creams, as well as for the synthesis of biodegradable packaging that, if applicable, can reduce the environmental impact caused by petroleum packaging. Other parts, such as the head and the viscera, contain polyunsaturated fatty acids and other fat-soluble vitamins that have been studied for the production of omega-3 capsules for the pharmaceutical industry, but when the extracted oil does not fit the feeding parameters, it can be applied for the production of biodiesel. Furthermore, fishes are a promising source of astaxanthin, a carotenoid with high antioxidant properties. The use of combined techniques such as chemical and enzymatic methods can increase the extraction yield and favor the obtaining of more purified compounds, in addition to promoting the reduction of chemicals that are aggressive to the environment. In general, conscious production in the fishing industry through the valorization of waste generated for use as inputs for other value chains encompasses aspects of the circular economy, which can positively impact several Sustainable Development Goals.     

Thermal formation of PBDD/F from tetrabromobisphenol A--a comparison of polymer linked TBBP A with its additive incorporation in thermoplastics

For a long period, polybrominated flame retardants are under discussion because of the formation of polybrominated dibenzo-p-dioxins (PBDD)/dibenzofurans (PBDF) (PBDD/F) in case of thermal stress. Concerning polymer linked tetrabromobisphenol A (TBBP A), formation of PBDD/F was commonly presumed to be sterically hindered because of the covalent fixation into the polymer backbone. Combustion experiments with additively incorporated TBBP A compared with its polymer linkage revealed, that this assumption is incorrect and has to be revised. Under same conditions, similar PBDD/F concentrations in the range of 17.5-19.6 mg PBBD/F per kg TBBP A applied were analyzed. PBDD/F homologue distribution patterns were almost identical predominated by low brominated PBDF. These findings for PBDD/F formation have to be considered in future discussions regarding thermal stress caused by combustion or recycling processes, including other flame retardants bound in polymer matrix, e.g. polybrominated polystyrene (PS), or those with molecular structures showing less analogy to PBDD/F, like hexabromocyclododecane. The second aspect introduced, is the influence of different plastics on the formation rates of PBDD/F. In this context, combustion experiments were performed in an atmosphere consisting of synthetic air and HBr. PBDD/F concentrations were 8.47 mg/kg polyethylene, 1.67 mg/kg PS, 3.92 mg/kg phenolic resin and 18.1 mg/kg epoxy resin. Distribution patterns of PBDD/F homologues could partly be correlated with the occurrence of the precursors polybrominated benzenes and phenols.     

Nativ-basierte Grundöle für die Produktion von Kühlschmierstoffen

Aims and Scope

Compared to mineral oil products, cooling lubricants based on fatty acid esters have technological advantages. Moreover, they are more environmentally compatible and make a contribution to a sustainable economy. Nevertheless, they are rarely applied in practice, because of their comparably high price, that is based on raw-material and synthesis costs. Alternatives concerning raw-materials and synthesis pathways are considered and properties of resulting ester products are compared.

Methods

The investigations aimed at three fatty acid-2-ethyl-hexylesters that were synthesized in an enzymatic-catalytic routine based on peanut oil, suet, and waste edible fat and at esters that were conventionally produced from animal and plant fats and 2-ethyl-1-hexanol. Physical properties, fatty acid patterns, contents of free fatty acids, as well as oxidative and hydrolytic stabilities were determined. Thermolysis experiments were performed.

Results

The physical properties of the seven esters, density, viscosity, pourpoint, and flash point, were comparable and gave reason for the assumption, that the products could be used as basis oils in lubricant formulations. Hydrolysis stabilities of the esters were high and thermal stress did not point at high potential of hazardous compounds formation. Especially the enzymatic-catalytically produced esters showed deficits concerning oxidation stabilities and free fatty acid contents.

Outlook

For practice it will be necessary to define minimum qualities for raw-materials and resulting ester oils to be used as lubricant basis oils. Moreover, processes have to be developed, that yield high quality ester products from waste edible and animal fats without loosing the advantage of low-cost raw-materials by high production and refinement costs. Surely, one contribution is the further development of the energy-saving enzymtic alcoholysis for ester production.