Engineering and scaleup of biopulping
- USDA Forest Service, Madison, WI (United States)
Biopulping, defined as the fungal pretreatment of wood chips for mechanical pulping, saves energy during refining and improves paper quality. Current research efforts have focused on scaleup of fungal pretreatment in chip piles and process design to bring the process to the industrial level. To achieve this goal, several engineering questions need to be addressed, including decontamination, cooling, and aeration. Experiments have shown that steam exposure as short as 15 seconds sufficiently decontaminates the surface of the chips. Subsequent cooling with blown air reduces the temperature of the chips sufficiently to allow inoculation. Since the first large pile revealed the need for cooling to promote optimum growth, an aeration system was developed to provide relatively sterile, humidified air. Using well-instrumented, insulated reactors, the effects of heat buildup in tall stacks was simulated. The control strategies developed are effective in the 360-kg reactor. From these experiments, several engineering parameters for heat generation as a function of time and temperature, characteristics of air flow through the chips, and compressibility of the chips have been identified. We used this information in an air flow model to predict cooling air requirements and to evaluate air distribution systems.
- OSTI ID:
- 370059
- Report Number(s):
- CONF-960376--
- Country of Publication:
- United States
- Language:
- English
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