Better resource utilization: This benefit of establishing ethanol distilleries is related to increasing production of sugarcane. It is understood that serious consideration is being given to the possibility of the forward integration of sugar cane producers into ethanol production facilities. Integration of sugar and ethanol production can also provide for the production of storable syrup that can extend the working week or the working season of the fermentation and distillation works.

Assessment of the potential for alcohol production from sugarcane and other agricultural crops. The article discusses some of the alternatives that exist for large-scale ethanol production. Thus, it can be seen from Table 2 that the estimated cost of processing cane into ethanol is 20.6 cents per liter of ethanol product.

The cost of the cane at the mill must be added to the processing costs.

Table 1. Factory Gate Costs of Liquid Fuels from Various Sources*

THE CURRENT STATUS OF ENERGY FARMING IN NEW ZEALAND*

THE CURRENT STATUS OF ENERGY AGRICULTURE IN NEW ZEALAND*. method and then investigated in detail the kinetics of the process under different temperature and pressure conditions. Some of the most important recommendations in the energy agriculture study relate to building the research on topics that are not currently being researched. The costs of raw materials are shown together with the proportion they represent of the total costs.

The Minister of Energy is an enthusiastic supporter of the idea of bringing energy farming to commercial scale. Time is needed to explore and fully prove the variations in the technology and to solve some of the problems (e.g. waste management) associated with energy farming. Much of the workshop was in favor of effective control and coordination of energy agriculture research and development across government departments, universities, etc.

The material in this paper was prepared by members of the Energy Farming Research Group and their respective institutions: Professor J.B.

Table 1. Interrelationships of Energy Crop Land Suitability (hectares)

PROSPECTS AND TECHNOLOGY FOR FUEL ETHANOL FROM GRAINS

Cereals and whole grains, on the other hand, meet all the requirements now. Because of ethanol's potential role as a fuel extender in the short to medium term, it is important that expertise in these areas be developed rapidly. The substrate is introduced into the bottom of the tube and the ethanol is removed at the top.

Over the next twelve months, it is planned to expand this aspect of the work to various sugar mill juice streams as carbon sources. The cost of this treatment is likely to be of the same order of magnitude as the cost of fermentation itself. High product concentration — the economics of the distillation stage are improved with a higher concentration of ethanol resulting from fermentation.

In the case of ethanol production, however, the potential gains in productivity are limited due to the inhibitory effects of high ethanol concentrations on yeast growth and ethanol production.

Table 3 shows typical current market values for various common protein com- com-modities from which it can be seen the values ascribed above for yeast and grain pro-teins are not unrealistic

Time (hrs)

Most microorganisms will, for teleological reasons, stop the synthesis of cellulase enzymes in the presence of glucose or other metabolizable carbon sources. When this program began, cellulolytic bacteria were only used for the production of microbial proteins, and fungal cellulase preparations such as those produced by T.reesei were to be used for the production of glucose from cellulose (saccharification). the cellulolytic activity of the mutants isolated in this program allowed the development of saccharification processes based on bacterial enzymes,7 which is the first such process to be reported. In the T. reesei preparation, the presence of 6 percent glucose reduces the activity of the preparation to 20 percent of the activity present at zero glucose concentrations.9 In the Cellulomonas system, the presence of 8 percent glucose only reduces the activity to 80 percent of that present at zero glucose concentrations.

Reactor studies of the saccharification stage involving a counter-current reactor to achieve maximum recirculation of the enzyme. Assessment of the value as animal feed of the biomass and residual cellulosic materials produced as by-products of a cellulose-to-ethanol process. Agricultural and forestry liquid fuel production in Australia: resuming a national potential study.

Hypercellulolytic mutants and their role in saccharification' in Proceedings of the Second Annual Fuels from Biomass Symposium.

ORGANIC COMPONENTS OF DISTILLERY WASTES

Dextrose' column (developed by Waters Associates in Australia) was used to subfractionate the oligosaccharide component when necessary. We have now made a preliminary assessment of the possibility of converting ethanol and aqueous ethanol into hydrocarbons over the ZSM5 catalyst. We saw in Dr. MacLennan's paper this afternoon the value of the protein in distillation in terms of viability in the production of ethanol, especially from cereal crops.

If we start making all our sausages from the byproducts of an ethanol fuel industry, my friends in the meat industry won't be too happy. The Chair: I think Dr MacLennan pointed out the urgency of the problem as he saw it in Australia. All we can do, I think, is look at the swings we see in the price of protein commodities that exist today.

A lot of the work that needs to be done would be refining existing processes – the optimization of something we already have.

Figure 3. Products from Ethanol at 420 °C Figure 4. Ethylene Formation

LIQUID FUEL PRODUCTION FROM AGRICULTURE AND FORESTRY IN AUSTRALIA

RESUME OF A SURVEY OF THE NATIONAL POTENTIAL

The largest single source is methanol from existing cropland residues, which is about one quarter of the total (105 PJ). The potential production of liquid fuels from residual cereal grains and energy crops is more than half of the total (230 PJ), and the potential production of sugar cane, forestry and cassava is about one quarter (100 PJ), one sixth (75 PJ) and one thirtieth (14 PJ) of the total amount. For simple alcoholic biomass fuels, the cost of one liter of motor gasoline equivalent is 3 to 4 times the price of refinery motor gasoline (with a small difference between ethanol and methanol).

Capital cost of the very large plants (18 to 99 PJ per year) for coal mining plus conversion to methanol or motor spirit is $10 to $15 per GJ (109J) of gross annual output. This is equivalent to more than half of the current annual use of liquid fuels for transport in Australia. The net liquid fuel output is calculated by subtracting the following energy input components from the gross liquid fuel output: a) the amount of liquid fuel used directly;.

Australian Institute of Petroleum (1977) Oil and Australia 1977 — the figures behind the facts. 1978) 'Methanol production in Australia' in Conference on Alcohol Fuels, Sydney, Institute of Chemical Engineers (NSW) 9-11 August, 1978.

Table 1. Arable land use in 1975-6 and potential areas for energy crops on new land in Australia (million hectares)

ENERGY CROPS IN AUSTRALIA: CASSAVA

Areas with more than 1000 mm of rainfall are limited to the coastal plain and highlands of eastern Queensland, the Cape York Peninsula and in the Northern Territory, areas north of the Daly River. Growth of cassava, without irrigation, will probably be limited, even in areas with high total annual rainfall. Experimental cassava sites have been successfully grown on a wide range of soils in northern Australia, with the exception of heavy self-mulching soils, saline soils and soils with poor internal drainage.

The dual soils that occur in large areas of coastal Queensland will be a major consideration for cassava production. The last areas of great development have been the mechanization of planting and harvesting, which in the past was done almost entirely by hand. Climatic demands, however, may limit potential production, regardless of major irrigation inputs, in areas of the east coast of Queensland and parts of the Atherton Tableland.

Before large-scale production of cassava can be considered, several areas of research and development will need to be clarified.

Table 1. Yields of Fresh Tubers, Harvest Index, Tuber Dry Matter and Fermentable Sugars of Cassava at Bundaberg under Drought Conditions

ENERGY CROPS IN AUSTRALIA: SUGAR BEET

The British consultants in their first report (Beet Sugar Developments Ltd 1977) reviewed the area of land suitable for sugar beet production in Tasmania. Consequently, it was concluded that a potential average root yield for a sugar beet industry in Tasmania would be approximately 50 tonnes per hectare with a sugar yield of 8 to 9 tonnes per hectare. At this stage we have made an estimate of the likely size of the farm gate price of sugar beet to enable it to be competitive with other crops in Tasmania.

As a result, it is considered that a gross margin of at least $700 per hectare will be required to make sugar beet a profitable crop for Tasmanian farmers. This means that the gross income for sugar beet must be at least $1340 per hectare. The potential average root yield for a sugar beet operation in Tasmania would be approximately 50 tonnes per hectare with a sugar yield of 8 to 9 tonnes per hectare.

The variable costs of sugar beet farming in Tasmania are estimated at $640 per hectare and a gross margin of at least $700 per hectare would be required to make sugar beet a competitive crop.

Figure 1.- Total Area Available for Beet Production (Adapted from Beet Sugar Dev. Ltd 1979)

ENERGY CROPS IN AUSTRALIA: SUGAR CANE

The use of sugarcane bagasse is one of the few cases where agricultural crop residues are used as an energy source for product processing. If sugarcane is to be grown as an energy crop, total biomass (soluble carbohydrates and fiber) becomes important. The availability of fiber in combination with soluble carbohydrates is the main advantage of sugarcane as an energy crop.

Four potential irrigation areas in Northern Australia – the Ord and Fitzroy Rivers in Western Australia and the Burdekin and Fitzroy Rivers in Queensland are considered suitable for sugarcane production. The 285,000 hectares of additional sugar cane harvested each year could yield 3.53 million tonnes of sugar, bringing Australia's total sugar production to 6.3 million tonnes. Sugar cane is normally harvested between June and early December, when the sucrose content of the sugar cane is at its highest.

An increase of 285,000 hectares in the area of sugarcane harvested annually in Australia is potentially possible and if all the sugarcane produced in this area were used for ethanol production, this would account for 2.4 GL or 12 percent of the current needs for motor fuel and car distillate in Australia are. could be produced.

Table 1. Average production data for Queensland sugar districts, 1969-78

ENERGY CROPS IN AUSTRALIA: SWEET SORGHUM

However, for sweet sorghum to be used in such a process, it must be similar in physical characteristics to sugarcane. It has been shown at the Hawkesbury Agricultural College that a pilot scale counter-current extraction system, similar to that used in the sugar beet industry, could be used successfully for the extraction of sweet sorghum. To date, the literature on sweet sorghum has been limited mainly to sucrose content, pol value and c.c.s.

The labile nature of the juice was considered a weakness in the use of sweet sorghum and sugar cane for energy. At the Hawkesbury Agricultural College, sweet sorghum juices were stored at room temperature with various concentrations of sodium metabisulphite (1000 mg/L to 2500 mg/L). It was found that sweet sorghum juice does not need to be amended with nitrogen and phosphorus macronutrients.

A general screening test for the selection of microorganisms suitable for sweet sorghum juice up to 27 percent w/w sugar was also performed.