A long-standing ACD customer developed a new food grade product in 2012 and scaled up to commercial production in 2013. The product applications were very sensitive to the presence of any darker particles in the final powder so the use of fine mesh sifting screens was required to meet the customer’s specifications. This sifting generated a substantial amount of powder that contained an excess of dark particles and could not be used by ACD’s customer.
As a result, the material containing dark particles had to be discarded as waste and the early yields for the product were between 75-85%.
Both ACD and the customer were very interested in increasing the product yield to above 90% by either reducing the amount of material containing excessive dark particles or by developing a procedure to remove the dark particles and recover the waste material.
In collaboration with the customer, ACD’s Research and Development team developed a plan for recovering the waste material by mixing the powder with water to form a solution, filtering out the dark particles, and spray drying the material a second time. The efficacy of the mixing and filtration steps was first demonstrated in ACD’s Pilot Plant. Then a trial of the re-drying step was conducted at commercial scale in ACD’s food grade spray dryer, during which the powder produced from the recovered waste material met all of the customer’s specifications. Samples of the trial material were provided to the customer for further analysis, microbiological testing, and application testing.
The customer confirmed that the powder produced following the recovery procedure developed by ACD was in specification and usable for downstream applications. Since then, ACD has followed the same procedure for recovering waste material during each of the customer’s spray drying campaigns. The average product yield since implementing the recovery procedure has been 96%.