Sugar Beet Trash

February 5, 2009

ISSUE 207

A Vincent KP-16 press was installed at a sugar beet plant in Sidney, Montana for the 2008-2009 campaign.  The press is used to dewater beet stems, small beet chips, and weeds which are separated from the whole beets during the washing process. 

40% of world sugar supply comes from sugar beets.  Extraction of sugar (99.9% pure sucrose) from the beet involves three major stages:  preparation, diffusion, and purification.  During the preparation stage the beets are washed and then cut into long, thin strips called cossettes.  The cossettes are sent to a countercurrent diffusion column where 98% of the beets’ sugars leach into hot water.  Lime and carbon dioxide are mixed with the sugar enriched water to remove impurities, and the sucrose is eventually crystallized using evaporators and centrifuges. 

Eight Stord screw presses are used to dewater the sugar-depleted cossettes.  These presses reduce the moisture content of the beet pulp to below 75% moisture.  In 2007, the pulp was sold as cattle feed for $6/ton.  This year the price is $12/ton.  (The pulp has not been dried and pelletized for several years.)  

Until this year the beet stems, small beet chips, and weeds removed during the wash cycle were collected in a heap and hauled away for a fee.  The trash was eventually plowed into fields to minimize odor and to act as fertilizer. 

This year the Vincent KP-16 screw press is dewatering the trash to 76-78% moisture with cone pressure set to 80psi.  The press is currently producing 3-4TPH of press cake, and it could easily handle a load three times larger.    The cake from the Vincent press is added to the cake from the Stord presses and sold as cattle feed. 

Since sugar beet processing is a "24x7" operation, the Vincent press is generating an extra 500-700 tons per week of saleable material.  At 2007 prices, this equates to additional $3,000 per week potential cash flow.  With a rental price of $650/week, the KP-16 easily pays for itself.  Plus, there is no longer any disposal fee associated with the wash cycle waste.