Less fuel in harvesting maize

Maize is one of the New World plants nobody else had experienced before 1500. Compared with wheat or rye, it certainly looked peculiar. The grain is hidden in a wrap of leaves, the many kernels attached to a large core (cob). The two ‘ears’ per plant stick out at a height convenient to pick by hand. Also, the kernels are large and relatively soft, with no need for a miller. It is little wonder maize became so popular with growers.

Commercial production at a large scale is another matter. Today, the combine harvester is generally used, with only grain leaving the field. But this style of harvest is peculiarly expensive with maize.

The combine is a general-purpose harvester used in many different crops. It is a mobile thresher being fed material by a detachable front unit, of which there are several types meant for other crops. A maize header picks the ears from the plants, strips off the leaves wrap, and then sends cobcorn (naked ears) into the machine’s maw.
The threshing action is much too aggressive, with cobs being broken into small bits. Then freed kernels are gathered, and the broken bits of cob ejected. No surprise that threshing is the largest use of the engine’s power, and a big engine is both necessary and a major cost item for this expensive machine.
If instead cobcorn were wanted, a combine harvester would no longer be used in maize — only the front-end unit would be attached to something else.

Cobcorn Harvester

Comparatively, little power is used to pick, strip, and deliver cobcorn. A self∙propelled unit may be the maize header fronting something like the tractor end of a self∙propelled windrower.

A conveyor to a wagon or box receiving the cobcorn completes this picture. Such a ‘cobcorn harvester’ is a less complex machine with a smaller engine, so less cost to build and then less expensive to buy. Due to much less fuel being used in the field, it also will be cheaper to operate. And there are other cost differences, with yet more fuel saved.

Loose grain coming off the field is often too moist to store safely and, unless dried, may rot. Typically, fossil fuel is burnt to heat the air blown through the grain. How much depends on the moisture in the grain, which in part depends on weather conditions at harvest.

However, any farmer growing a large amount of maize is sure to harvest some that are too moist to store safely because it is impractical to wait for all the crops to dry to an acceptable level. So, they will always incur a drying cost that varies greatly.

Natural Drying

Drying cobcorn is a breeze comparatively, as it uses natural air circulation. Unlike loose grain, which packs closely, cobcorns have much air space around them, and air moves through easily. If necessary, fans can blow more unheated air through.

Since cobcorn is less expensive to harvest and less costly to dry, profitability is not the primary consideration in the choice of harvesting system for maize. Convenience is.

It is inconvenient to harvest ears as cobcorn and store them for many weeks before separating the grain from the cobs. However, one positive is a lower investment in portable machinery specific for maize, mainly when using a smaller machine over a long run of days. And if it is powered by electricity, this would further reduce the total fuel use of the farm.

No one focussed on profits first, last and always would use a combine harvester in maize. This creates doubt about whether farmers are capitalists, even though most economists presume they must be.

Markets for Cobcorn

In the USA, and Europe, to a lesser degree, ethanol by fermentation is based on maize. But this starchy grain is mainly used to feed livestock. At times it can be pricey, which is one reason why this style of ethanol production has iffy economics. It usually needs some form of subsidy to be financially viable.

Cobcorn could change this situation, depending on how it is priced and used in the ferment. Likely, cobcorn would be valued at the same price as the grain it has. This benefits the farmer, who avoids the expense of threshing. Though less noticeable, the fermenter need not thresh the cobcorn either.

Yeast or bacteria will only tolerate a low percentage of fermentables in the water they inhabit. That may be provided from the kernels without removing them from the cob. Puncture or slice the tops of the kernels, then immerse the cobcorns in hot water, having in it the enzymes used to turn starch into something the microbes can use. Drain that water and send it to the fermenters. Alternatively, flow water containing enzymes repeatedly over the prepared cobcorn.

Once all the starch has disappeared, the soggy cobs can be sent to a furfural digester on site. Furfural is made only from plant material, and being high priced, would be another significant income stream for the fermenter.

Of course, there would be other changes besides, but even this brief glimpse should be enough to demonstrate that a market for cobcorn can exist, and it is a large one, given how much fermentation ethanol is being made. [Though 2,3∙butanediol is a better choice of ferment to produce an engine fuel and should displace ethanol.]

Hybrid Power

Returning to the cobcorn harvester, it could have hybrid power, a combination of combustion engine and storage. Not electric batteries but hydraulic oil under high pressure as storage, with hydraulic motors doing all the work, including moving the wheels.

It would mean the engine runs at full power or off, making it fuel efficient. Its only purpose is to provide high-pressure hydraulic fluid. Given a reasonably large reservoir on board, that reservoir could be charged with pressurized fluid at the beginning of each day using an electric motor and pump, further reducing the amount of combustion fuel used on the farm.

The cobcorn harvester has almost all the crop∙specific parts in the detachable header unit, and as the weeks of harvesting are not many, the tractor end of it may work the rest of the year in or near the farm yard.

It could then rely mainly on the electric route of fluid pressurizing. Perhaps also on a windmill pump with a large reservoir. Either or both would lessen the total annual use of combustion fuel on the farm for this equipment.

Theo Hart