Biopulping: A new energy-saving technology for papermaking
Biopulping is defined as the treatment of wood chips with lignin-degrading fungi prior to pulping. Fungal pretreatment prior to mechanical pulping reduces electrical energy requirements during refining or increases mill throughput, improves paper strength, reduces the pitch content, reduces cooking time for sulfite pulping, and reduces the environmental impact of pulping. The recent work involved scaling up the biopulping process towards the industrial level, investigating both the engineering and economic feasibility of the technology. The authors envision the process to be done in either a chip-pile or silo-based system for which several factors need to be considered. These factors include the degree of decontamination, a hospitable environment for the fungus, and the overall process economics. Currently, treatment of the chips with low pressure steam is sufficient for decontamination. Furthermore, a simple, forced ventilation system can be used to maintain the proper temperature, humidity, and moisture content throughout the chip bed, thus promoting uniform growth of the fungus. The pilot-scale trial resulted in the successful treatment of 4 tons, of wood chips (dry weight basis) with results comparable to those on a laboratory scale. For mechanical pulping, a 2-week treatment results in approximately 30% energy savings that, considering the additional equipment and operating costs, results in an overall savings of $9 to $20/ton of pulp in a chip-pile system. The other benefits that biopulping confers improve the economics considerably A larger, 40-ton trial was also successful, with energy savings and paper properties comparable with the laboratory scale.
- Research Organization:
- Dept. of Agriculture Forest Service (US)
- OSTI ID:
- 20001944
- Report Number(s):
- CONF-970750--
- Country of Publication:
- United States
- Language:
- English
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