The overall process is designed to operate with coarse-milled grain. Grain fragments as large as ¼ of a kernel are allowed without an adverse impact on process operations or efficiency. Several plants have demonstrated a measurable increase in ethanol yield per bushel of grain with increased screen sizes. The coarse grind milling system provides for reduced power and maintenance on the milling equipment. In addition, the increased particle size distribution improves the operating efficiency of the decanter centrifuges, evaporators and DDGS dryers.
Facilities are designed to process numerous cereal grains without major changes in process equipment, plant configuration or operating practices. Feedstocks capable of being processed include but are not limited to: corn, grain sorghum or milo, wheat, barley, triticale, field peas, cassava, sugar beets, sugar cane, potatoes, molasses, and cheese whey permeate.
The design of the liquefaction process combines the auto-refrigeration mash cooling process with enzymatic hydrolysis into a single process step. The net effect is a process with minimal pieces of process equipment, reducing the installed cost and operating costs relating to power requirements, maintenance, and consumption.
SSF was first commercially implemented by KATZEN in 1981 at a plant capacity of 65 million gallons per year. The starch-based SSF process was developed in association with KATZEN’s activities relating to technologies for the enzymatic hydrolysis of cellulosic feedstocks. Today, SSF is the fermentation process used in 90% of grain-based ethanol plants in operation.
The highest ethanol yields in the industry have been demonstrated on a sustainable basis in KATZEN plants. The yield is a result of an overall process technology package which:
Provides for extended operations without downtime for cleaning column internals. Operations periods of over four years between maintenance have been demonstrated in KATZEN plants.
The distillation system is designed for pressure cascade operations providing for high efficiency, minimal downtime and reduced capital equipment costs.
The use of our rectifying column operating at elevated pressures eliminates the need to revaporize the molecular sieve feed, reducing the associated energy demand and equipment cost.
Provides for extended operations at product solids concentrations up to 40 wt.%.
The overall process design and demonstrated high yield fermentation results in an exceptional quality DDGS. The reduction in the concentrations of unconverted starches and bacterial metabolic byproducts results in higher protein content DDGS.
KATZEN processes call for total recycle or recovery of all process fluids including:
Major processes and equipment items can be designed for future application in biomass-to-ethanol process. Units operations are designed for:
KATZEN-designed plants are capable of processing high-moisture corn (greater than 25 wt.%) providing a reduction in feedstock costs due to the elimination of the drying step normally required by the grain producer. Furthermore, a plant that processes high-moisture corn can take direct delivery of the feedstock, which eliminates costs associated with elevator storage of grain.
Integrated feedlot plants are able to directly feed wet cake to livestock thereby eliminating the drying process. This results in a significant reduction in capital investment and eliminates the corresponding costs of operating and maintaining the equipment associated with the drying process.
The plant operating costs are further reduced due to the shared overhead between the feedlot and ethanol production facilities.