Gasification of leather waste for energy production: Laboratory scale and industrial tests

The following paper presents in detail the results of two separate test runs of the leather waste gasification process. The first one was conducted in a laboratory and the second in an industrial installation with 2.5 MW of thermal power. The aforementioned gasification plant transforms 1000 kg/h of various leather waste with ER = 0.38-0.4 producing hot producer gas with a calorific value of 4.1-6.5 MJ/m(3) used for steam production. This local energy center uses waste from a leather processing factory to secure the energy needs of the host plant and produces ashes with up to 55% of Cr2O3 suitable for Cr recovery and reuse in the tanning process. The gasification of refuse-derived fuel derived from the used leather goods illustrating the effectiveness of separate collection and thermal transformation of Cr containing waste was tested as a path to closing the chrome economy cycle in the leather industry. Moreover, the effectiveness of Ca(OH)(2) for the purification of flue gas resulting from syngas burning and removal of SO2 and HCl was taken into account. Ashes analysis from gasification and flue gas cleaning showed very low Cr(VI) content. The study, according to the laboratory and industrial-scale tests, proves that gasification leads to effective energy conversion of leather waste and can be advantageous in comparison to incineration, mainly due to producing safer ashes that are easier for handling and processing, with the simultaneous production of valuable syngas.