Hi Allen: I don't think you will get saleable honey from rendered old combs. It is very dark and has poor flavour. You may be able to use a variant of my method for separating wax from cappings. The cappings are put in a barrel with an equal weight of warm water. I have a 1/3 hp electric motor with a 5/8" shaft extension and a 6" diameter propeller made from twisted 16 gauge stainless steel. I run this for about twenty minutes and then pump the honey/water mix out through a bag filter which retains the cappings. I feed the honey water back to the bees and they evaporate it back to honey.The wax is rendered separate from the honey. This yields bright yellow wax and quite clear honey/water. You would have to find some way to demolish your combs so that the water could get at the honey. (I use a scratcher to uncap, so my cappings are small grains to start with). You could warm them up in steam chest to about 110 deg F, bang the frame on a board over the barrel and then mince them up with the propeller mixer. The barrel would take about 150 lb of comb at a time so a steam chest that would do three supers at a time would be adequate. This stuff would be better fed back in the spring as it would make fairly poor honey.It is necessary that it be fed immediately after processing or it ferments. ( You might use it for making ethanol...) This method would realistically do 100 lb an hour.If you have 50,000 pounds you are looking at a couple of months. Feeding back that much honey would be a problem. The ethanol idea sounds better. Best regards Donald Aitken