Drying of beet pulp

Jensen, A. S., Steam Drying of Beet Pulp and Bagasse, Internal Sugar J., 105, 83-88 (2003). 

Although existing dryers using this concept are currently operational in Europe for drying of beet pulp, pilot tests indicate that this dryer can successfully dry the following products as well ... 

As may be expected, the net energy consumption of such dryers can be very small. Up to 90 percent fuel saving over conventional dryers has been reported for drying of beet pulp in a high-pressure fluidized bed dryer (Bosse and Valentin, 1988). 

Improvements in pulp pressing technology have enabled manufacturers to reduce the moisture content of pressed pulp from 80% (moisture-to-sohds ratio 4 1) to 75% (3 1 ratio), which has reduced the drying requirements by one-fourth. Beet pulp is much mote difficult to press than most vegetable products, but there are indications that moisture in the mid-60% (ratios <2 1) range may be achievable with properly designed equipment. 

In addition to the alfalfa hay, the cows received a grain ration which consisted of a mixture of 80% barley and 20% molasses dried beet pulp, to which were added 2% steam bone meal and 1% fine hay salt (sodium chloride). This ration was fed at the rate of 0.75 pound of grain per day for each pound of butterfat produced during the previous week. If the butterfat production dropped below 0.8 pound per day, the grain ration was routinely discontinued. 

The disposal of sugar beet pulp does not offer any very serious problem, since it can readily be dried and used as a cattle food and it is probable that all the available supplies are absorbed in this way. The utilization of molasses is discussed separately in Section VII. 

Diffusion. The cossettes are fed into the diffuser by means of a continuous weigher. Countercurrent hot water is introduced at the upper end of the diffuser. The extracted sugar leaves from the lower end of the diffuser as a grayish-black 10 to 15 percent sucrose solution called diffusion or raw juice. The extracted pulp is discharged at the top. The pulp contains residual sugar of approximately 0.2 percent of the beet dry weight. The pulp is pressed, dried, and enriched by the addition of 2 to 3 percent molasses. It serves as cattle feed. 

The pulp, leaving the diffuser after the extraction of sugar from the beet cossettes, is pressed in screw-t5q>e presses to remove water. The pressed pulp is enriched by the addition of molasses or concentrated Steffen filtrate and is dried in rotary driers. Molasses-dried beet pulp... 

A case study is presented for the HTU conversion of sugar beet pulp 130 kton/a on a dry basis). A process description is given, and the heat economy is discussed. For the generation of process heat some external fuel is required (2% of the heating value of the feedstock). 

C5H10O5, Mr 150.13. d-A. mp. 159-160°C, [a]n -175- -105° (H2O) l-A. mp. 160°C, [a]o +190- +105 (HjO). Monosaccharide of the aldopen-tose series. d-A. occurs only rarely in nature in bacterial polysaccharides. l-A. is frequently found in nature in plants, gums, hemicelluloses, pectins, bacterial polysaccharides, in the form of glycosides, glycocon-jugates, and heteropolysaccharides. l-A. is isolated from dried beet pulp. Aloe, and gums. ... 

Recently, Niro A/S of Denmark has successfully commercialized a pressurized-steam-fluid bed dryer for particulate and sludgelike or pulpy materials [9]. The fluid bed has a special cellular design and operates at 3 bar. The fluid bed is driven by superheated steam flow that is recycled through a heat exchanger by a fan and blown up through the fluid bed. Capacities of 2-40 ton/h water evaporation are available. Initiated at pilot scale in 1982, the full-industrial-scale dryer (6-m diameter) for drying beet pulp came on stream in Denmark in 1985. 

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