What I am imagining here is a high diameter drain pipe that attaches to a specialized macerator pump. This attaches to a specialized conical sink next to the conventional sink in a kitchen. The pipe leads to a composting aerator outside of the house. To minimize the potential for unpleasant odors the maceration pump is of a positive displacement style and the composting setup would be of a vented design. The rinsing of plates and serving ware into this special segment of the sink would also aid in keeping the pipe relatively clear. The collected compost may either be processed communally in the case of apartments or collected occasionally by a municipal utility if not used on site. For multiple user applications the addition of paper and other organic compostables to the blend might be done in an automated fashion while individuals would need to fine tune the ratio of digestives by manually adding non-food-stuffs to the heap. The system must be robust enough to force material down the pipe and also energy efficient enough to make routine use economical. The composter must be of a high aeration design with provision for draining excess liquid into the sewage system. The system should be safe and quiet with the ability to detect that a foreign object such as a spoon has been dropped into it.
-- WcW, Apr 30 2011

A very similar idea. Redundant? yes. Compost_20disposal
This idea needs more study. A convnetional disposall isn't adequate for this task. [WcW, Apr 30 2011]

random, halfbakery