Sweetening from sugar beet

Press, 7 March 1978, Page 17

Sweetening from sugar beet

“Reviving a technology that was left standing” is how Professor A. P. Mulcock, of Lincoln College, describes the present studies on blending ethanal with petrol.

Professor Mulcock has recently completed a survey with N. Kardos of ethanol production throughout the world.

Ethanol, or ethyl alcohol, is known to most people as a constituent of alcoholic drinks. It is also used as a fuel, a solvent, and a raw material for synthetic compounds.

As a fuel, ethanol has been used in the internal combustion engine for more than 80 years, so the idea of blending it with petrol is not new. It was used as a motor fuel until the Second World War when its use was limited by its importance as a military raw material. Since then it has been superceded by petrol.

The dramatic increase in the price of imported oil in the last five years has made part-replacement of petrol an attractive proposition. The survey by Kardos and Mulcock illustrates what is known about ethanol production, and suggests one way in which New Zealand could produce the fuel economically — through fermenting sugar beet. The survey admits that there has been no suitable replacement found for the internal combustion

engine, so that finding an assured fuel source for the engine is one of our major energy problems.

“When we become short of fuel for the internal combustion engine, we must look at what we’ve got,” says Professor Mulcock. He considers himself a realist, and is quick to admit that there are some major problems still to be overcome before a beetbased ethanol industry can be considered a viable proposition.

“L.P.G. may last 30 to 50 years: it is finite, and hardly likely to last any longer than that, so it is really no different from petrol. Sugar beet, on the other hand, is cyclical and self-perpetuating.”

He believes that the critical time in New Zealand’s energy scene will come aoout the year 2000, when oil and gas sources are expected to be depleted.

Sugar beet, of course, is a sensitive political issue. The Government is reluc* tant to approve a homegrown beet industry, but Professor Mulcock is optimistic that the Government may look more favourably at a proposal that will save the country valuable energy resources and overseas funds.

He also realises that the crop must be at least as economically attractive as present production on the best land. “The land required for growing sugar beet will be reasonably good land,” he says.

“I would be the first to say that if this land could be used to increase over-

seas funds — through selling mutton to the Arabs for petroleum imports, for instance — then there is no point in producing alcohol if you can get more from existing crops.”

Apart from the technical details of producing ethanol from sugars, there remains one major stumbling block in present production processes — the disposal of distillery wastes.

Severe pollution would result from dumping the wastes in rivers, lakes, or the sea, and it would be very expensive to convert the wastes into a usable spray.

“The idea would be to put it back into the soil from which it was grown,” Professor Mulcock says. He then suggests using it as an irrigation spray, or fermenting it one step further to produce methane, which might then be used to heat the still, and waste material poured on to the soil.

“Or you could add the waste material to something dry, like hay, and feed it to animals. You could then collect the dung, and produce methane from that.”

The final chapter of the survey is devoted to a study by R. J. Gillespie, of the Agricultural Economics Research Unit at Lincoln College. And, for the future of a beet-based ethanol industry, it is probably the most important part of the survey. Mr Gillespie estimates that there are 29,000 ha of land

available in New Zealand for producing the base crop. Sugar beet yields 35 or 50 tonnes per hectare, depending on whether it is grown under, dryland or irrigated conditions. The revenue to the farmer can be estimated by deducting all variable and. other costs and margins from the world price of ethanol, and it was found that sugar beet would be more than competitive with other crops, which could

be grown on the same land. Under present conditions, prices of at least $l3 and $l7 a tonne would need to be paid for irrigated and dry land sugar beet respectively, to ensure that it remained competitive. “It appears that an ethanol industry could afford to pay such prices,” the study concludes. Kardos and Mulcock have attempted ta estimate the final cost of eth-

anol to the car owner. Allowing for the cost of transport and distribution, wholesale and retail markup, and petrol tax added (when ethanol is finally blended), the cost per litre would be about 33 or 34 cents. The current retail price of premium petrol is 27 cents per litre.

The Government has undertaken to give L.P.G. a tax advantage over petrol, and Professor Mulcock agrees that this might also be suitable for ethanol.