(305a) Life Cycle Assessment of Advanced Regional Biomass Processing Depots Integrated with Sustainable Cellulosic Feedstock Landscapes

Lignocellulosic biomass can help fulfill escalating demands for liquid fuels and mitigate the environmental impacts of petroleum-derived fuels. Cellulosic biofuels also offer potential solutions to many socio-economic and sustainability problems caused by petroleum dependence. However, the large biorefineries which process cellulosic biomass to fuels face many logistical problems because they are fully integrated, centralized facilities in which all units of the conversion process are present in a single location. Biomass logistical problems are further exacerbated by physical characteristics of feedstocks such as low bulk density, compositional variability, seasonality and their tendency to decompose.

A potential solution to these problems might be a network of distributed processing facilities called “Regional Biomass Processing Depots” (RBPDs). In their simplest configuration these depots procure, preprocess /pretreat, densify and deliver feedstock to the biorefinery while providing a single co-product animal feed to end-users. However, the RBPDs can be configured into other, more complex setups by employing multiple technologies such as the ammonia fiber expansion pretreatment (AFEX), Leaf Protein Concentrate (LPC) extraction, leaf/stem separation, pyrolysis and anaerobic digestion, as dictated by feedstock characteristics and local conditions, to produce a variety of valuable co-products and for energy generation via synergies among these technologies.

In a previous analysis we considered the differences between distributed processing and centralized processing combined with a variety of landscape scenarios. This study established that combining high yielding perennial grasses with distributed processing that includes densification of AFEX treated biomass prior to transportation to the biorefinery may generate greater energy yields and lower greenhouse gas emissions compared to centralized processing. In this study we aim to extend this analysis to watershed- scales in various landscape configuration scenarios using more sophisticated geospatial information system tools as well as by including a wider range of feedstocks and sustainable management practices, including the use of marginal lands. On the processing side, we evaluate the energy balances and environmental impacts of advanced RBPDs and their associated transport systems. We then intend to integrate the various elements within this overall system and conduct a life cycle analysis (LCA) using the Gabi software.

Through an integrated systems-wide analysis and by developing flexible models we seek the most sustainable landscape-processing-transportation arrangements for cellulosic biofuel production. We believe that greater energy and environmental benefits can be added to biofuel production by not merely aiming at improved logistics but by reimagining agricultural systems and landscapes, minimizing the challenges associated with biomass supply and its processing and by investigating multiple, potentially synergistic processing technologies and related complexities.