Bioresource Technology, Vol.102, No.3, 2684-2694, 2011
Comparative life cycle assessment of three biohydrogen pathways
A life cycle assessment was performed to quantify and compare the energetic and environmental performances of hydrogen from wheat straw (WS-H(2)), sweet sorghum stalk (SSS-H(2)), and steam potato peels (SPP-H(2)). Inventory data were derived from a pilot plant. Impacts were assessed using the impact 2002+ method. When co-product was not considered, the greenhouse gas (GHG) emissions were 5.60 kg CO(2eq) kg(-1) H(2) for WS-H(2), 5.32 kg CO(2eq) kg(-1) H(2) for SSS-H(2), and 5.18 kg CO(2eq) kg(-1) H(2) for SPP-H(2)center dot BioH(2) pathways reduced GHG emissions by 52-56% compared to diesel and by 54-57% compared to steam methane reforming production of H2. The energy ratios (ER) were also comparable: 1.08 for WS-H(2), 1.14 for SSS-H(2) and 1.17 for SPP-H(2). A shift from SPP-H(2) to WS-H2 would therefore not affect the ER and GHG emissions of these BioH2 pathways. When co-product was considered, a shift from SPP-H2 to WS-H2 or SSS-H2 decreased the ER, while increasing the GHG emissions significantly. Co-product yield should be considered when selecting BioH(2) feedstocks. (C) 2010 Elsevier Ltd. All rights reserved.