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 is producing novel catalysts for the pyrolysis of biomass, with the goal of making robust, coke resistant catalysts. A newly installed CDS pyroprobe coupled with GC/MS was identified as a tool for evaluation of catalyst activity and deactivation. Pyroprobe testing of separate reactor for modeling deactivation was demonstrated. Results comparing various catalyst bed temperatures on rates of deactivation and product yields at constant pyrolysis temperature were produced. The results validated this approach and the choice of reactor configuration in the pyroprobe (in-situ vs. ex-situ) vs. others commonly encountered in the literature. Initial testing with various commercial zeolites, following the established protocol was started. Results of varying Si/Al ratio were also obtained; zeolites with Si/Al ratios ranging from 45 to 11 were tested, indicating much higher deactivation rates for the low Si/Al ratio catalysts. While these results highlight the importance of this ratio, these commercial catalysts did not contain the same crystal size indicating that further investigation is necessary. Therefore, novel ZSM-5 zeolites with varying crystal sizes from 20nm to 20 microns were prepared and characterized. Testing of these experimental catalysts is underway.