skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Design, testing and evaluation of a small scale injection cooker for ground corn

Thesis/Dissertation ·
OSTI ID:6562731

A continuous cooker for 0.2 kg/min of ground corn (Zea mays) was developed to match the expected alcohol fuel needs of a 300 ha Iowa farm. A commercial jet cooker (Hydroheater) was used, but the design and implementation of the slurry handling, enzyme dosage, pH adjustment, and automatic control were local. Pure corn starch and corn meal were used as feedstocks. Solids concentrations from 10 to 27% w/w were examined. The feedstocks were hydrolized with ..cap alpha..-amylase at temperatures from 97 to 124/sup 0/C, and saccharified at 60/sup 0/C with amyloglucosidase. Slurry samples at four locations were anlayzed for total reducing sugars (TRS). The same jet cooker was used under laboratory conditions to cook small batches of slurry; saccharification was done as a batch. Problems with the acid and base metering pumps led to poor pH control. The results for both cookers were analyzed using a response surface technique, because pooling all the results was expected to give some indication of the performance of a farm scale cooker operated with unsophisticated controls. The dependent variables were: 1) material efficiency, the fraction of starch converted to TRS, 2) conversion ratio, the ratio of TRS in the output supernatant to the input solids concentration, and 3) energy ratio, the ratio of the higher heating value of the TRS produced to the electrical and steam energy during conversion. The independent variables were solids concentration in the input slurry and the temperature of the cooking process.

OSTI ID:
6562731
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English