Studying Modified Cellulose Nanocrystals for Rendering Odors

Date: February 9, 2018

Principal Investigators: Daniel C. Whitehead, Clemson University and Frank Alexis, Yachay Tech, Ecuador

Keywords: Nanocrystals, Rendering Odors

Summary:

This project continues our prolonged efforts toward the development of new functional materials for technologies to reduce odor emissions from the rendering industry. At the beginning of our work with FPRF, the main target of this work was to develop engineered, biodegradable poly(lactic acid) (i.e. PLA) nanomaterials whose surface could be decorated with appropriate reactive sites (i.e. functional groups) that would, in turn, capture or destroy malodorous volatile organic byproducts of rendering processes. Briefly, by decorating the nanomaterials with appropriate reactive sites, offending volatile byproducts can be absorbed by the formation of either ionic or covalent bonds. In this manner, the malodorants are chemically modified so as to both harness them onto the biodegradable materials for disposal and to render them less odorous. With previous FPRF funding, we have successfully developed bench-scale technology that is capable of capturing targeted odorants associated with rendering processes.1,2 We have also parlayed FPRF support into further support from Clemson University Research Foundation in order to pursue scale-up and further optimization of our first-generation materials and subsequent iterations. So far, this study has served as a proof-of-concept exercise that unequivocally demonstrates that functionalized biodegradable poly(lactic acid) nanomaterials have the potential to become a next-generation strategy for odor remediation in the rendering industry. The materials work well for their intended purpose, and we have learned a lot about strategies for engineering novel materials for odor capture. Along the way, our extensive exploration of our first-generation polymeric materials based on the PLA platform has also uncovered some drawbacks that must be addressed on the way to a scaleable product that can be applied at rendering facilities. The disadvantages of our first-generation materials include the difficulty of synthesis, expense, batch-to-batch variation, difficulty scaling, and less than optimal thermal stability.

 

In an effort to address all of these issues, our more recent ACREC/FPRF proposals sought to build upon our previous successes in order to parlay what we have learned during the investigation of our first-generation materials into new strategies for the functionalization of cheaper, more robust natural materials including cellulose and aluminosilicate clay substrates. As such, we have successfully developed strategies for the modification of the much cheaper cellulose3 and clay4 platforms and have demonstrated that they are capable of capturing rendering malodorant VOCs. Importantly, these materials are easier to synthesize at a fraction of the cost. This 2018 project sought to expand upon these new, cheaper materials in order to 1.) assess the potential for a spray-based delivery application of PEI-modified Cellulose Nano-Crystals (i.e. PEI-CNCs), 2.) evaluate PEI-CNCs in a plant setting as a packed-bed scrubber, and 3.) lower fabrication costs and facilitate scale-up of PEI-CNCs.

 

The continuation of our current efforts has the potential to be very beneficial to the rendering industry. First, we are moving ever closer to realizing our goal of developing a scalable, cheap material for a next-generation alternative to established methods for odor remediation. In this context, the materials described herein might present several uses in an industrial setting. The materials could be employed as a rapid-use odor adsorbent in an emergency or spill situation. Further, the materials could, in principle, be incorporated into existing odor remediation equipment as an added means for odor elimination. This 2018 proposal evaluated whether aqueous suspension of PEI-CNCs can be administered as a spray-based formulation. The obvious long-term goal would be to develop an appropriate formulation of nanomaterials that would compete with or ideally supplant existing odor elimination measures.