Thermodynamic investigation and environment impact assessment of hydrogen production from steam reforming of poultry tallow

In this research, various assessment tools are applied to comprehensively investigate hydrogen production from steam reforming of poultry tallow (PT). These tools investigate the chemical reactions, design and simulate the entire hydrogen production process, study the energetic performance and perform an environment impact assessment using life cycle assessment (LCA) methodology. The chemical reaction investigation identifies thermodynamically optimal operating conditions at which PT may be converted to hydrogen via the steam reforming process. The synthesis gas composition was determined by simulations to minimize the Gibbs free energy using the Aspen Plus (TM) 10.2 software. These optimal conditions are, subsequently, used in the design and simulation of the entire PT-to-hydrogen process. LCA is applied to evaluate the environmental impacts of PT-to-hydrogen system. The system boundaries include rendering and reforming along with the required transportation process. The reforming inventories data are derived from process simulation in Aspen Plus (TM), whereas the rendering data are adapted from a literature review. The life cycle inventories data of PT-to-hydrogen are computationally implemented into SimaPro 7.3. A set of seven relevant environmental impact categories are evaluated: global warming, abiotic depletion, acidification, eutrophication, ozone layer depletion, photochemical oxidant formation, and cumulative non-renewable fossil and nuclear energy demand. The results are subject to a systematic sensitivity analysis and compared to those calculated for hydrogen production from conventional steam methane reforming. The LCA results indicate that the thermal energy production process is the main contributor to the selected environmental impact categories. Improvement actions to minimize the reforming thermal energy and the transport distance are strongly recommended as they would lead to relevant environmental improvements. (C) 2013 Elsevier Ltd. All rights reserved.