Reactors for scaling-up coal bioprocessing.

摘要

Although considerable research has been done on the biochemistry and microbiology of coal bioprocessing, relatively little attention has been paid to the type of reactor in which these processes could be carried out on a commercial scale. This is unfortunate for two reason. First, no bioreactors currently exist for large-volume low value solid products like coal. Second, the cost of building the reactor will be major of the economic feasibility of these processes must await the selection, optimization and first-stage scale-up of the reactor. The reactor must provide, at minimum cost, an environment in which the highest possible number of cells can work at their maximum specific rates. This implies a high concentration of finely ground coal and rapid transfer of nutrients (including O(sub 2)) and products to and from the coal surface. Unfortunately these are mutually exclusive without a large investment in energy for mixing. Some cell recycle will be essential to keep the microbial concentration high without the cost of buying nutrients to grow new microorganisms. Possible bioreactor types, including slurry reactors, ''heap'' reactors and fluidized beds will be discussed along with new problems arising from the possible use of genetically engineered organisms. 18 refs., 4 figs., 1 tab. (ERA citation 15:032067)