Leather processing for commercial purposes involves going through a set of complex and laborious operations, resulting in over 70% waste relative to the initial feedstock; a quarter of this waste is produced in Europe. Worldwide there are about 36,000 companies active in this sector, generating a turnover of almost 48 billion euros. As in any industrial sector, waste recovery is a highly researched topic, with alternatives for its use being constantly considered. One of the most interesting solutions to this problem consists of using part of the waste for power applications. For instance, the 10% fats from total animal waste could well be employed to power diesel engines, both in raw state or as biodiesel. The remainder, which contains mostly proteins, can be exploited to obtain biogas through anaerobic digestion. This paper presents the results of experimental determinations on the combustion of animal fats and compares it to other biofuels, such as vegetable oils and solid biomass. The advantages of co-firing hydrogen-rich gas (HRG) and vegetable biomass are also analyzed. According to the presented results, combustion of the investigated fuels has a lower impact on the environment, with the concentration of pollutants in the flue gases being low. Thus, the paper proves that all the proposed solutions are ecological alternatives for biomass exploitation for energy recovery purposes, based on comparing the results in terms of pollutant emissions. This paper provides qualitative and quantitative perspectives on multiple alternatives of energy recovery from biomass resources, while also briefly describing the methods and equipment used to this end.
Numerical and experimental investigations on inflow loss in the energy recovery turbines with back-curved and front-curved impeller based on the entropy generation theory
