1a. Objectives (from AD-416):
The objective of FarmBio3 is twofold: (i) to leverage the existing synergies among partners to further research and optimize pyrolysis pathways to commodity fuels and chemicals and improve the TRL 4 status already achieved at ARS and (ii) increase to on-farm scale that will enable the current state of technology to, TRL 6, commercial status.
1b. Approach (from AD-416):
Will focus on three feedstocks that are important to U.S. agriculture including switchgrass, horse manure and woody biomass. The primary conversion platform will be catalytic and non-catalytic fast pyrolysis for production of stable fuel intermediates. Because barriers to utilization of such intermediates are high we will develop more robust multi-functional heterogeneous catalysts to balance deoxygenation pathways to minimize oxygenate production while increasing carbon efficiency for the selected feedstock pool. Bifunctional catalysts will be developed to upgrade and optimize carbon distribution in the condensed phase pyrolysate to achieve C6-C14 hydrocarbons and target entry to gasoline, diesel and jet range fuels markets. We will develop and optimize homogeneous catalysts to break C-O bonds of the lignin fraction of lignocellulosic pyrolysate to produce specialty chemicals. Pyrolysis process improvements will be integrated at on- the-farm scale using an existing patent-pending dual fluidized bed, combustion-reduction integrated pyrolysis, unit (CRIPS) designed to mimic the fluid catalytic cracking (FCC) process. Using real process data from this scale up and optimized upgrading, an exergetic LCA will be performed to describe not only economics and greenhouse gas emissions but also resource depletion and loss of quality for distributed on-farm thermolysis; this will be the first complete economic, environmental, and social sustainability analysis for on-farm pyrolysis.
3. Progress Report:
This is a sub-award for a NIFA funded Biomass Research & Development Initiative project (FarmBio3) for which ARS is the principal investigator. The collaborator selected homogeneous catalyst systems which were previously reported to perform C-O bond breaking in lignin model compounds, and then they tested those catalysts on pyrolytic lignins produced at ARS. A manganese-based compound was found to produce low molecular weight compounds from lignin. They also synthesized new catalysts for the breakdown of lignins into valuable chemical products. Also synthesized were several small molecule models of the different C-O linkages that are present in lignin, so that the reactivity and selectivity of the new catalysts can be tested in a more controlled manner. Analytical and chemical testing of pyrolyzed Etek lignin provided information on how the structure of lignin changes during pyrolysis. Similar studies with switchgrass lignin are underway.