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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Bioproducts Research » Research » Research Project #432304

Research Project: Optimizing Almond Coproducts: Continuous Torrefaction of Shells as Plastics’ Additives and Isolation of Hull-Derived Sugars for Bee Diets

Location: Bioproducts Research

Project Number: 2030-41000-058-14-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Jan 15, 2017
End Date: Sep 30, 2019

Objective:
California almond processors have seen a significant reduction in their returns on shells due to excess supply, with few viable commercial outlets. Shells have generally been used as bedding for cattle, but with increased almond production and decreases in the dairy cattle industry, there are fewer viable market outlets for shells. The industry needs to find more commercial uses for shells to provide broader market applications. One option being pursued by USDA researchers and their partners is to add value by thermal conversion of the shells to various forms of “biochar”, which are then used in several commercial products. While prototypes have been made and preliminary data may support these ideas, the USDA research team needs to scale-up their thermal processing into a continuous process that can provide viable quantities of biochar for further testing at a commercial level. Our objectives are to 1) purchase, install and test a (previously used) rotary furnace, 2) produce viable biochars from shells on a continuous basis at the pilot-scale, so that we can commercially-viable prototype models, 3) create prototype commercial products using biochar from shells as additives and enhancers and 4) present prototype materials to industrial partners for their review. Investigate and optimize sugar and phenolic extraction from almond hulls, characterizing solutions for sugar and tannin composition.

Approach:
We will first install the rotary furnace. We will then examine the effects of temperature, time (residence time in the furnace) and size of output particles (grind mesh) as well as the effect of grinding samples before or after thermal treatment. Basic measurement of the biochars’ output properties will include product yield, particle size, moisture uptake and color. We will create prototype commercial products using biochar from shells and then present prototype materials to industrial partners for their review. Apply rapid bee-testing assays to see if honey bees will consume bee diets rich in hull sugars and phenolics. 2. Investigate and optimize sugar and phenolic extraction from almond hulls, characterizing solutions for sugar and tannin composition; Apply rapid bee-testing assays to see if honey bees will consume bee diets rich in hull sugars and phenolics.