Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2009
Publication Date: 12/30/2009
Citation: Butts, C.L., Sorensen, R.B., Nuti, R.C., Lamb, M.C., Faircloth, W.H. 2009. PERFORMANCE OF EQUIPMENT FOR IN-FIELD SHELLING OF PEANUT FOR BIODIESEL PRODUCTION. Transactions of the ASABE. 52(5):1461-1470. Interpretive Summary: In an on-going project to produce peanuts for on-farm production of biodiesel, researchers found that one-third of the biodiesel production costs were due to drying, cleaning and shelling the peanuts. A conventional peanut combine normally used to simply harvest the in-shell peanuts, was modified to shell the peanuts, separate the hulls from kernels, and accumulate the shelled peanuts. Test were conducted during the 2008 harvest and shell peanuts while harvesting using a conventional grain combine and the modified peanut combine. The grain combine harvested 62% of the harvestable peanut kernels of which 93% where shelled. The modified peanut combine harvest 91% of the harvestable peanuts and shelled 99% of those. By allowing the peanuts to completely cure in the windrow, then harvest and shell with the modified peanut combine, the postharvest costs can be reduced from $2.29 to $1.46 per gallon of peanut oil.
Technical Abstract: Drying, cleaning, and shelling peanuts represents approximately one-third of the costs of growing, harvesting, and processing peanuts for oil extraction. A conventional two-row peanut combine normally used to thresh windrowed peanuts was modified to shell the peanuts as they were harvested. Peanuts were dug, windrowed and allowed to partially dry in the windrow. They were then harvested using the modified peanut harvester, and a conventional grain combine. As a control treatment, peanuts were harvested using the modified peanut combine with the shelling grates removed from the sheller. The modified peanut combine successfully captured 91% of the peanut kernels harvested in the control and shelled 99% of the kernels harvested. The grain combine captured only 62% of the peanut kernels. The grain combine shelled 93% of the peanuts harvested. Peanuts harvested with the grain combine had 30% foreign material compared to 11% harvested with the modified peanut combine or the control. Allowing the peanuts to dry in the windrow and shelling with the modified peanut combine reduced the estimated post harvest oil production costs as much as 36% from $611/1000 L of oil to $391/1000 L.