Scientific Opinion on a continuous multiple-step catalytic hydro-treatment for the processing of rendered animal fat (Category 1)
An alternative method for the treatment of rendered animal fat (Category 1) intended for the production of renewable fuels by a continuous multi-step catalytic hydro-treatment process was assessed. The alternative method is based on a pre-treatment by degumming and bleaching followed by a hydro-treatment comprising three main processes: catalytic hydro-treatment, stripping and isomerisation. The minimum processing conditions are pressure 30 bar, temperature 265°C and retention time 20 minutes. Based on the outcome of previous EFSA Opinions and the expert evaluation, the BIOHAZ Panel considered that a reduction of six log10 in the transmissible spongiform encephalopathy (TSE) agent by the alternative method is necessary to consider the process at least equivalent, for Category 1 animal by-products, to the processing methods previously approved. Experimental data in the reviewed literature showed that similar processes at temperatures between 160 and 200°C deliver at least a 6 log10 reduction in TSE infectivity in 20 minutes. Thus, at least a similar level of reduction is expected to be produced by the alternative method proposed. This is in addition to the inactivation achieved by the pressure sterilisation method applied prior to the application of the alternative method. The treatment under assessment is considered to achieve the required level of TSE inactivation, as long as the critical limits of key parameters are achieved as specified by the applicant. The minimum retention time is a critical parameter. The applicant’s estimate of minimum retention time is based on the reactor size and the flow rate of the material, but the real minimum time in actual processing conditions has not been determined. It should be confirmed that a minimum retention time of 20 minutes is achieved in all parts of Category 1 material under normal operational conditions in order to ensure the effectiveness of the treatment.