Location:
2017 Annual Report
Objectives
1: Enable commercial processes for transforming animal protein into new marketable flocculants.
1a. Develop processing techniques for the solubilization of rendered protein with emphasis on intact proteins and high molar mass protein fragments.
1b. Evaluate technological alternatives for transforming raw chicken blood into a high potency flocculant at low processing cost.
2: Enable market growth for flocculants based on animal proteins by improving their performance and expanding their market applications.
2a. Apply a series of covalent modification strategies to improve blood and rendered protein flocculant performance.
2b. Identify particular application areas to which blood and rendered protein flocculants are well suited.
Approach
Both rendered protein and chicken blood have inherent flocculant properties, but these substances also have other properties which make them unsuitable for commercial flocculant applications in their ‘raw’ state. Poor solubility is a primary obstacle to commercial utilization of rendered protein as a flocculant. Instability, high water content, and dark red color are among the obstacles to blood utilization. The project will focus on developing processing techniques for surmounting these obstacles under Objective 1. With the current state-of-the-art, rendered protein or blood flocculants have significant performance limitations. Improving their performance through covalent modifications is the focus of Objective 2a. Finally, any class of flocculants is well suited to some particular application areas and not to other areas. In Objective 2b, the focus is on identifying particular application areas appropriate for rendered protein and blood flocculants.
Progress Report
This project focuses on improving the performance and commercial viability of experimental biobased flocculants, and creating economic impact by transferring the technology developed to industry. It addresses NP306 Action Plan Component 2, Problem Statement 2.B, “Enable technologies for producing new marketable nonfood biobased products derived from agricultural products and byproducts, and ensure that these technologies will create economic impact by estimating their potential economic value.” Over the past year, substantial progress was made towards each of the project’s objectives.
One of the agricultural substances that has been used for flocculant production is known as ‘meat and bone meal’ (MBM). Objective 1a addresses the problem of the low solubility of MBM protein. During the reporting period, two efforts were completed in support of this objective. The first project investigated whether a particular protein hydrolysis method that had been demonstrated at small scale would be practical for larger scale production of flocculant. The researchers found that two processing steps used in the earlier research were unnecessary; this finding significantly reduced MBM processing cost estimates. On the other hand, researchers also observed problematic inhibition of the hydrolysis reaction at larger scale, but after identifying the source of the inhibition, were able to devise a simple workaround. This technology has been transferred to an international firm under a formal agreement, so that the firm can attempt to replicate the results at full scale. The second project addressing Objective 1a examined industrially practical methods for solubilizing MBM protein without hydrolysis. Although moderately good results were achieved by applying a variety of chemical treatments to the protein, much better results were achieved using appropriate conditions of elevated pressure and temperature. This finding is substantial because it achieves the objective without the expense, safety concerns or pollution potential associated with chemical treatments.
The research group also uses slaughterhouse blood as a feedstock for flocculant production. Objective 1b is intended to examine how a blood-based flocculant could be commercially produced. Although this objective does not have a milestone in the reporting period, additional work beyond what was planned was accomplished by working with a commercial partner under a CRADA, funded by an SBIR phase I grant. The collaborating firm uses a fraction of slaughterhouse blood to make an existing product. The work reported here determined the parts of blood not used by the firm can be processed into a high performance flocculant, thus producing two valuable products from the same blood. The success in this project has resulted in the awarding of a SBIR phase II award, which is intended to support research towards commercialization.
There is reason to believe that while the naturally occurring flocculant properties blood and MBM proteins are very good, they can be improved upon, and that doing so would make the protein-based flocculants more attractive for technology transfer. Objective 2a seeks to improve performance through protein modification. In the reporting period, researchers pursued a strategy improving performance by increasing molecular weight of the flocculants. Hemoglobin from blood was successfully cross-linked by chemical and enzymatic means. This results in two or more hemoglobin molecules joined together, effectively creating a substance of much higher molecular weight. Whether the cross-linked hemoglobin has the desired increase in flocculation performance has not yet been determined.
Flocculants are used in a huge variety of industries, and Objective 2b is centered on identifying particular application areas for which protein based flocculants are well suited. During the reporting period blood-based flocculants were used to treat a by-product stream known as “thin stillage”. Normally, the solids and nutrients in thin stillage are recovered by evaporating the water, which requires a large amount of energy. Recovery of solids by flocculation is much less energy intensive. Research showed that pig blood or purified hemoglobin could effectively recover the suspended solids in thin stillage. This flocculation treatment by itself did not recover phosphate for the stillage, but it was found that it could be used in conjunction with another treatment that causes phosphate to precipitate.
Accomplishments
1. Development of a magnetic, bio-based substance for removal of water contaminants. Some industrial wastewaters, including the dye-contaminated wastewater from textile manufacture, are treated with activated carbon to physically adsorb the contaminants. Activated carbon, however, is expensive and usually not re-usable. ARS researchers at Wyndmoor, Pennsylvania developed a novel substitute for activated carbon using hemoglobin from slaughterhouse blood. The substance is an insoluble co-precipitate of hemoglobin and iron salts which adsorbs multiple types of dye comparably to activated carbon, but in contrast to activated carbon it can be easily recovered using a magnet, and after a simple reactivation step, can be re-used multiple times. This patent-pending technology is expected to create a new use for very low value slaughterhouse blood, and provide an attractive solution for water pollution control.
2. A new approach for making rendered protein more useful. Rendered protein is not soluble, and therefore not useful for many value-added applications. Past attempts at overcoming this problem by cutting the protein into smaller pieces have been unsatisfactory because the protein loses most of its useful properties when cut into very small pieces. ARS Researchers at Wyndmoor, Pennsylvania identified a simple reaction that instead cuts the protein into large, soluble pieces which retain useful properties. The researchers showed that this reaction could be used despite the degraded nature of MBM (meat and bone meal) protein and the presence of non-protein interfering substances. The technology was transferred to a rendering firm that needed a hydrolysis method like this for producing a new line products based on rendered protein.
Review Publications
Zhang, C., Garcia, R.A., Piazza, G.J. 2017. Solubilization of meat & bone meal protein by dilute acid hydrolysis for the production of bio-based flocculant. Journal of Food and Bioproducts Processing. 102:362-366.
Piazza, G.J., Lora, J., Garcia, R.A. 2016. Flocculation of wheat straw soda lignin by hemoglobin and chicken blood: Effects of cationic polymer or calcium chloride. Journal of Chemical Technology & Biotechnology. doi: 10.1002/jctb.5061.
Garcia, R.A., Nieman, C.M., Haylock, R.A., Rosentrater, K.A., Piazza, G.J. 2016. The effect of chicken blood and its components on wastewater characteristics and sewage surcharges. Poultry Science. 95(8):1950-1956. doi: 10.3382/ps/pew114.
Piazza, G.J., Garcia, R.A. 2016. Biobased flocculants derived from animal processing protein by-products. In: Dhillon, G. Protein Byproducts. Canada: Elsevier. p. 135-146. doi: 10.1016/B978-0-12-802391-4.00008-2.
Essandoh, M., Garcia, R.A., Strahan, G.D. 2017. Methylation of hemoglobin to enhance flocculant performance. Journal of Chemical Technology & Biotechnology. doi: 10.1002/jctb.5197.
