Beyond 2025: Transitions to
the biomass-alcohol economy using ethanol and methanol
Barney Foran1 and
Chris Mardon2
1
CSIRO Resource Futures
Program, Canberra
2
Consultant,
Melbourne
The National Dryland
Salinity Program
of the
Land and Water Resources
Research and Development Corporation
December 1999
Contents
Contents..................................................................................................................................................................................................
2
Foreword..................................................................................................................................................................................................
3
Executive summary................................................................................................................................................................................
4
Chapter 1 Biomass fuels from a world perspective.........................................................................................................................
9
Chapter 2 Biomass fuels from an Australian perspective...........................................................................................................
17
Chapter 3 The production of ethanol from woody biomass..........................................................................................................
23
Chapter 4 The production of methanol from woody biomass.......................................................................................................
32
Chapter 5 Modelling the transition to biofuels..............................................................................................................................
40
Chapter 6 Locating biomass plantations.........................................................................................................................................
82
Chapter 7 Caveats and uncertainities.............................................................................................................................................
88
Appendix 1 The OzEcco embodied energy model of Australia’s physical
economy................................................................
93
Appendix 2: Cost Estimates for Ethanol and Methanol..............................................................................................................
108
Foreword
This research report was developed in response to a request from the Land and Water Resources Research and Development Corporation that the CSIRO Resource Futures Program prepare a discussion report on 'biomass opportunities for fuel generation and recharge reduction'.
Particular thanks are due to a number of people who contributed to the process. Firstly Nicholas Newland, the National Coordinator of the National Dryland Salinity Program of LWRRDC, who organised this opportunity. Then my co-author and colleague Chris Mardon who wrote Chapters 3 and 4. Reviewers offered many helpful and challenging comments in particular Allen Kearns Acting Chief of CSIRO Wildlife and Ecology, Bob Gordon of the Fuel Alcohol Association of Australia, Russell Reeves from APACE Limited, Dr. Stephen Schuck from the Biomass Taskforce and Dr. Franzi Poldy from the CSIRO Resource Futures Program. John Bartle from the Farm Forestry Unit of the Department of Conservation and Land Management in Western Australia provide a wide range of up to date information on the rationale and development of the oil mallee industry in that state. Many other colleagues helped with facts and sources of information.
Lastly to Greenwords and Images in Canberra who contributed an exacting edit and helped with layout.
Barney Foran
Program Manager
CSIRO Resource Futures Program
CSIRO Wildlife and Ecology, Gungahlin, Canberra
December 1999
Disclaimer
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neither CSIRO not its agents or employees are liable to any person for any
damage or loss whatsoever which has occurred or may occur in relation to that
person taking action in respect of any statement, information or advice given in
this publication.
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Executive summary
1 In the context of national environmental policy, it is generally recognised that the function of Australia’s farmed landscapes requires policy attention and large-scale remediation. Diverse sources note that by 2020, between 10 million and 40 million hectares of more-intensively used land may have declining function because of the combined problems of dryland salinity, soil acidification, nutrient and structural depletion and fragmentation of biodiversity resources. This report explores scenarios that envisage replacing large areas of cropping and pasture lands with perennial deep-rooted production systems which help halt, and then reverse, the dryland salinity challenge. The rationale for such an undertaking is to facilitate the transition from the hydrocarbon economy to the carbohydrate economy by using biomass to produce ethanol and methanol as replacements for traditional oil-based fuels and feedstocks.
2 The control of dryland salinity and associated problems of landscape function pose an immense challenge for monetary investment and physical action. The scale of the problem will require action over one to four human generations, or 25 to 100 years. In implementing a biomass-based economy this study provides wider rationales for the solution of the problem, rather than just the refurbishment and rehabilitation of broadscale landscape function. The first of these is to present a new industry which requires deep rooted plants, large areas and which has the ability to attract investment and produce employment and prosperity for rural Australia. The second is to prepare in advance for the possible constraints to national production and prosperity posed by a run down in Australia's domestic stocks of oil. The transition to a biomass-alcohol economy is able to link these seemingly separate future issues.
3 Australia relies heavily on transport services and petroleum fuels that maintain its far-flung economy. Within the next human generation the domestic stocks of traditional oil may become constrained, the shortfall having to be sourced from imports, thereby contributing to an increasing import bill and additional balance of payments tensions. There are a number of domestic energy sources which could meet this shortfall These sources include natural gas condensate, liquefied natural gas, oil from oil shale deposits and liquid fuels from biomass.
4 Many developed economies in Europe and North America are investing heavily in the research and development needed to underpin the transition towards renewable forms of energy, including biomass fuels. The strategic reasons are: biomass-based energy sources for heat, electricity and transportation fuels are potentially carbon neutral, that is, they recycle the same carbon molecules; domestically sourced energy reduces reliance on imports which might be affected by market and political instability; biomass-based fuel cycles potentially employ more people than fossil-fuel based cycles.
5 Australia’s farmed landscapes, the industries sourced from them and the regional economies that depend on them require deep-rooted perennial crops to help mimic the function of ecosystems that are now gone or non-functional. The key physical attributes needed from these systems are such that they halt the leakage of water and nutrients which now contribute towards dryland salinity and soil acidification. Tree and shrub crops, many of them Australian native plants, are potentially suitable for this task. Supplying biomass fuels and carbohydrate feedstocks may provide a strong economic, political and market rationale, one human generation from now, when Australia’s domestic oil stocks may be constrained.
6 In the international and Australian context there are two biomass based liquid transportation fuels that might replace petrol. These are ethanol and methanol. Bio-diesel is also a well-developed technology. Ethanol is viewed in North America, Brazil and Australia as a more useable fuel that can be readily blended with petrol, used as an octane enhancer and even as a 100% replacement for petrol with suitable engine modifications. Methanol appears to be the substitution fuel of choice in Europe, particularly for new generation cars powered by fuel cells. Methanol is more toxic, acidic and corrosive than ethanol, it requires larger fuel tanks per unit of energy, but is still amenable to 100% replacement of petrol with appropriate engine technology. Current commercially available cars (flexible fuel vehicle or FFVs) in the United States have sensing technology which adjusts engine tuning and performance to the fuel in the tank (petrol, ethanol, methanol and blends), so future vehicle fleets need not be disadvantaged by the regional availability of different fuel types.
7 The ethanol process is produced by biologically catalysed reactions (fermentation) after pre-processing with dilute acid solutions (hydrolysis) which make five carbon sugars (pentoses) and six carbon sugars (hexoses) more available to the fermenting organisms. A wide variety of feedstocks can be used, including grains, whole crops, wastes and woody materials. The yield (in terms pure ethanol yielded per 100 kg of dry feedstock) varies from 40 kg for high sugar crops (sugar cane, sugar beet and sweet sorghum) to 25 kg for waste streams (bagasse, newspapers and processing waste) to 16 kg for woody materials. A commercially sized ethanol from wood plant producing 50 million litres per year is expected to require a capital investment of $50 million to $70 million per plant and 200,000 to 300,000 dry tonnes of feedstock per year supplied from a 30 km to 40 km radius of the plant. Commercial developments currently under way in Australia promise the possibility of a step change in the process efficiency of the ethanol production system. In particular two parts of the process, the concentrated acid hydrolysis of the feedstock to liberate sugars for fermentation, and the acid-alcohol separation and subsequent acid recycling, have received US patents and are being integrated into a pilot production plant.
8 Methanol is manufactured primarily by thermal processes where biomass is gasified to a synthesis gas, and the carbon monoxide and hydrogen in the synthesis gas are reacted over a catalyst to form methanol. Much commercial methanol is also sourced from natural gas in very large industrial-scale plants. The yield from the woody biomass process is 40% (400 kg of methanol per 1000 kg of dry wood) and should soon increase to 50% with process development. The methanol process can be undertaken in smaller-sized modules which may suit small business scales. These modules can be transported between sites, thus reducing the biomass transport component inherent in a large centralised plant if the source of feedstock becomes more remote.
9 Simulation experiments with the OzEcco embodied energy modelling framework showed that a transition to an ethanol transport fuels system is feasible. By the year 2020, an ethanol fuels industry could replace traditional oil-based hydrocarbon fuels for transport and could generate around 160,000 direct jobs, most of them in rural Australia. By 2050, it could reduce carbon dioxide emissions by more than 300 million tonnes per annum. If feedstocks not digested in the ethanol process were used to cogenerate electricity, then the carbon dioxide reductions could total 500 million tonnes per annum compared to the base case. Other advantages include a reduction in the fossil energy intensity of gross domestic product (GDP), expressed as megajoules of fossil energy required to generate a constant dollar, and considerable reductions in hydrocarbon imports with subsequent advantages in the visible balance of payments account. However, there are some areas of concern arising out of the simulation experiments. These are driven in turn by the initial assumptions used in the studies. Since crop biomass is assumed to make up 50% of the biomass feedstock for the production chain, the large tonnages required drive up the energy inputs to the agriculture and forestry sector by a factor of six times compared to the base case. The energy ratio for the whole ethanol production system declines from 6:1 initially to between 2:1 and 3:1 (two to three times the output of useable energy per unit of energy input to the production system). More detailed work on modelling the biomass production system in the model might improve these outcomes, but the results accord with the published literature internationally.
10 Similar simulation experiments for a transition to a methanol transport fuel system in Australia gave superior results due mainly to the assumption of a superior yield of dry wood to methanol on a weight for weight basis (compared to the ethanol production system). The methanol system reduced carbon dioxide emissions by between 200 million and 500 million tonnes per annum, depending on whether the experiment produced methanol alone, or electricity by cogeneration in addition. There was a substantial change over time in the energy intensity of GDP and by 2050 it reduced to one-quarter the level of the base case (2 MJ of fossil energy per constant dollar compared to 8 MJ per constant dollar in the base case and 6 MJ per constant dollar for ethanol). Up to 400,000 direct jobs were stimulated by the methanol fuels system by 2050. The energy ratio (output versus input on a system-wide basis) varied from 4:1 to 5:1, almost double that of the ethanol fuel system. One radical version of the methanol system managed to decrease carbon dioxide emission back to 1990 levels by 2050, but it also decreased physical measures of per capita affluence and reduced rates of yearly growth in GDP.
11 The land required for a managed perennial tree and shrub production system varied from 12 million to 31 million hectares, depending on the particular set of simulations undertaken. These are large areas of land and were assumed to come from the higher-rainfall pasture lands, and from croplands requiring rehabilitation due to dryland salinity, soil acidification and general problems of depletion. Although these are large areas in an immediate policy sense, the transition process is a steady one over long time scales. The areas required are within the land stocks and rainfall zones representing Australia’s more intensively farmed zones. Simplifying assumptions of a 20-year rotation with a 20 m3 per hectare mean annual increment (ie 400 m3 of wood per hectare after 20 years), drove the gross demand for biomass plantation area noted above. These assumptions are consistent with a range of current studies on carbon sequestration and carbon trading.
12 12 As well as providing a source of liquid fuels for Australia’s transportation systems, the development of biomass farming allows Australia to progress from the hydrocarbon economy to the carbohydrate economy where feedstock for chemicals and plastics is also derived from biomass rather than petroleum. A common characteristic for integrated bio-refineries is t hat ethanol is just one of a number of valuable co-products produced. The range of co-products would include chemicals, lubricants, solvents, plastics, paints, building materials and a range of starch and protein by-products. Gaining a foothold in the practice and the knowledge required for this new form of energy agriculture or the green chemistry of the future, could allow Australia to leap-frog many of its international competitors and gain market position and market advantage. The mallee oil developments under way in the Western Australian wheatbelt show the way ahead for these next-generation agricultural industries.
13 As well as helping the Australian economy meet some long-term strategies through energy self sufficiency and import replacement, the biomass-based alcohol fuel transition over the next 25 to 50 years could be expected to stimulate many opportunities for employment, mainly in regional and rural Australia. Replacement of today’s 1000 PJ of petroleum consumption with alcohol fuels, could provide 50 long-term jobs in each of 1000 to 1600 local alcohol production units (50,000 jobs nationally), and four to five times that number (200,000 jobs) to grow and deliver biomass and to service these primary activities. The construction and maintenance of the biomass fuel system, phased in over the next 25 to 50 years, would ensure many more jobs in construction and engineering sectors as well as revitalising Australia’s light industry base. The transport of Australia's biomass-alcohol fuels from country to city could stimulate a revival in transport infrastructure and services in rural and regional Australia, especially in rail services.
14 Current economic assessments based on price alone do not make a compelling case for a transition to a biomass fuelled economy. Step changes are possible in the efficiency of use for both transport fuels and electricity by applying technologies and management methods currently available off the shelf. The overall efficiency of coal fired thermal electricity plant is still below advanced technologies that are currently available. Coal in Victoria and southern Queensland is relatively low in sulphur and cost approximately $0.5 per GJ. The opportunity cost of woodchips for export is $164 per tonne dry weight or $8.3 per GJ, or 16 times the cost of coal. Ethanol or methanol with a future production cost of $0.8 to $1 per litre is still four times more expensive than unleaded petrol before excise and taxes. Much of the rationale for the transition to a biomass will therefore not rest on simple price arguments. Instead issues such as new industries for the twenty first century, jobs for rural Australia, productive refurbishment of farmed landscapes, carbon neutral fuel cycles and import replacement of transport fuels will form a richer and more complex suite of rationales.
15 The future of petroleum industries, transport technologies and the alcohol fuel systems cannot be predicted with assurance in the 25 year to 50 year time frames used in this analysis. New forms of vehicle transportation systems based on fuel cells could stabilise, and then reduce, Australia’s overall requirement for domestic transportation fuels. However, those developments seek to use ethanol, methanol and hydrogen to help meet global greenhouse requirements and city air pollution challenges. Australia might find new oilfields and thereby delay the economic and trade-balance imperative to move to new fuel systems. At the same time, technological developments within the science of alcohol fuel production promise substantial increases in the process efficiencies and potential cost decreases. Whatever the fallout between these issues, Australia’s farmed landscapes will still be seeking and requiring, deep-rooted perennial cropping systems to help redress the problems of landscape damage caused by the land clearance and annual cropping systems developed over the past 150 years.
16 The choice of alcohol fuel produced by the biomass-alcohol system is the subject of increasing debate particularly in the United States. The future of methanol, particularly MTBE the octane enhancer derived from methanol, in under increasing scrutiny following evidence of ground water contamination by MTBE in California. The Governor of California has issued a regulation calling for a total ban on the use of MTBE by 2002 and other US states are considering similar legislation. The degree to which the combustion of ethanol and methanol in appropriately engineered and tuned cars contributes to air, land and water contamination, now and in the future, is beyond the scope of this report. Both alcohol fuels should be closely examined in relation to a range of key environmental issues and also compared to the current fossil fuel transport cycle.
17 Biomass-based alcohol fuel systems are not yet proven to be ecologically sustainable. It would be a mistake to impose short rotation woody cropping systems on Australian farmed landscapes on vast scales without addressing the issue of long-term sustainability. There are four issues with which to contend. The retention of branches and leaves is probably necessary to ensure nutrient recycling and maintenance of soil organisms. Large-scale tree and shrub plantings may dry up overland flow from catchments, further affecting our challenged inland river systems and restricting water flows for our irrigation industries. The use of productive biomass systems that are exotic, regionally or nationally, could further reduce the function of native ecosystems and further depress survival and resilience of native plants and animal communities. Finally these initial analyses should be viewed as a guide to further work needed, rather than the final answer. The analytical approach is, by nature and design, broadscale, approximate and ignores much of the detail that is important at the fine scale of how society, governance, markets, real people and real landscapes function. More detailed investigations are required to explore the many unknowns highlighted in this study.
Chapter
1
Biomass fuels from a world
perspective
‘What is certain, however,
is that fossil fuels will face ever increasing competition from renewable
energy. I believe that over time, surpluses will arise and we may – ultimately –
leave oil and gas in the ground – as we are leaving most of the coal in the
ground.’
Heinz Rothermund, Managing
Director
Shell UK Exploration and
Production
20 May 1997, Glasgow
Abstract
A number of drivers operating on long time-scales and from regional to global scales are suggesting the possibility of a paradigm shift in how energy supplies, so crucial to the functioning of societies and economies, will be sourced and delivered. The drivers are a unique combination of threats and opportunities. The threats are obvious and are usually highlighted by the environmentally concerned and aware part of society. They include depletion of oil supplies, concern about greenhouse gas emissions and possible global warming, and the challenges posed by the inequitable distribution of economic production within and among countries. The opportunity part of the shift is built on the possibility of a carbohydrate economy. In this economy a lot of transportation fuels, heat, electricity, chemical feedstocks and commodity products would come from plant or biomass resources. This opening chapter brings together some of the relatively new directions in technology, land use and energy supply that might form the basis for the carbohydrate economy as the transition is, or might be, made over the next 100 or more years.
Overview of the context
of biofuels
The business and political climate
The views of economic writers, market analysts and business leaders towards global greenhouse gas emissions, the prospect of global warming and the contributions that fossil fuels make to these issues, are changing. Robinson (1999) notes that on Wall Street markets ‘the renewable-energy growth stocks are outperforming the fossil fuels groups for good reasons…they are facing monumental litigation…New York State has just launched a massive lawsuit against 17 coal-burning plants in upwind states citing pollution and the failure to update their emission control systems’.
Major multinational energy companies are now promoting views that respond to the question ‘how far it is sensible to explore for and develop new hydrocarbon reserves given that the atmosphere may not be able to cope with the greenhouse gases that will emanate from the utilisation of the hydrocarbon reserves discovered already’ (Rothermund, 1997a). These views also note the ‘renewables could provide half of the world’s energy by 2060’. This scenario is now part of a company catch-cry: the ‘50-50 Vision, that is ‘that by 2050, 50% of world energy will be supplied by renewables’ (Rothermund, 1997b).
There are immense barriers to implementing these visions, many of which are embodied in the layers of the institutions that maintain the modern economy. Rosch and Kaltschmitt (1999) note that the impediments lie in five key areas: difficulties with funding, financing and insuring; unfavourable administrative conditions; organisational difficulties; lack of knowledge or adequate flow of information; and insufficient perception and acceptance. Faced with these institutional barriers and the considerable technical difficulties still to be surmounted, a crisis may be required to provoke community and political action.
The carbohydrate economy
Many writers see that we are now at the beginning of the transition from the hydrocarbon economy (or more specifically fossil fuel economy) to the carbohydrate economy. Lynd et al. (1999) make the point that ‘biocommodity engineering is the application of biotechnology to the production of commodity products and offers huge benefits in terms of sustainable resource supply and environmental quality…and is the only foreseeable source of organic fuels, chemicals and materials’. They also note that ‘multi-product and integrating refineries which produce fuels, chemicals, power and feed will be essential for the viability of economic systems and will need to be integrated into the broader resource, economic and environmental systems in which they operate’. Some authors, for example Okkerse and van Bekkum (1999), claim that the world as a whole will have to move to a plant-based economic and social system just to survive past the year 2050. They also note that land area may be limiting and that the socioeconomic implications for achieving this transition are immense. Other authors, for example Morris and Ahmed (1998), claim that the carbohydrate economy is the way to solve both the environmental crisis and the farm crisis in the United States. Morris uses the symbolism of current activity and technology in the ethanol industry as ‘the runway from which to launch the carbohydrate economy’ and further notes that ‘the challenge now is to move plant matter derived products from the margin of the economy to its centre’.
Carbon-neutral fuel cycles
The main advantage of a biomass-based fuel cycle is that it has the potential to recycle the same carbon molecules and thus reduce the emissions of carbon dioxide into the atmosphere. Examples of biomass-based transportation cycles which reduce carbon dioxide emissions in comparison to a gasoline fuel cycle include: ethanol from corn (–16%), ethanol from biomass (–76%), and methanol from wood (–66%) (International Energy Agency, 1998). The process of accumulating carbon molecules to transform into a biofuel such as ethanol or methanol can be understood in a pine forest under a 28-year rotation cycle. A total of 230 tonnes of carbon per hectare is accumulated by photosynthesis over the 28 years and 115 tonnes is located in the logs harvested at the end of the management cycle. The remaining 115 tonnes of carbon remains on site after harvest and oxidises over time. This stored carbon in the logs is released again during the process of making and then using the biofuel.
Developing a carbon-neutral fuel cycle is a complex process and to date has been seen as too costly in dollar terms and too inefficient in useful energy output, compared to transportation fuels from the highly developed and highly integrated fossil fuel and petrochemical industry. Grado and Chandra (1998) have evaluated a fully integrated ethanol fuels system using biomass where the production cost was US$0.45 per litre of ethanol. In a sensitivity analysis of the important determinants of final price per litre, Grado and Chandra found that the ethanol yield from feedstock accounted for 44% of total variability of final cost, the capability of harvesting equipment accounted for 37% and the plantation yield accounted for 9%. Analyses such as these emphasise the requirement for critical breakthroughs in processing technology before carbon neutral fuel cycles can compete on cost and dependability. However, taxes on emitted carbon, as currently levied in some European countries, could make the carbon-neutral fuels equally cost competitive to current liquid fuels from fossil sources.
Industrial systems in place
The Brazilian ethanol-from-sugar cane system produces 15 billion litres of ethanol each year saving 250,000 barrels of oil imports per day. There are 339 distilleries providing 700,000 jobs and each production system, producing 50 million litres of ethanol per year, is responsible for more than 2000 jobs. These are much lower paid jobs than in Australia, but this picture provides some idea of the scale of the enterprise. A total of 220 million tonnes of sugar cane is grown each year in Brazil and 65% or 175 million tonnes is used to produce sugar cane. The sugar cane productivity is 65 tonnes per hectare for an average of 5000 litres of ethanol per hectare, which, at US$0.45 per litre, gives returns of US$2250 per hectare. Over the whole production system a capital cost of US$20,000 was required to make one job.
The ethanol-from-corn system in the United States produces 5.3 billion litres of ethanol from 550 million bushels of grain. There are 51 ethanol plants in 19 states and five more are being built. Canada has six ethanol plants and produces 201 million litres per year. A detailed life cycle analysis (Shapouri et al., 1995) shows that the ethanol-from-corn system is not particularly defensible from an energy yield point of view. The net energy ratio is estimated to be 1.24; that is, for every unit of fossil energy input over the whole production system, 1.24 units of useful ethanol energy are produced. The authors of this report go on to argue that ‘ethanol production utilises abundant domestic energy supplies of coal and natural gas to convert corn into a premium liquid fuel that can extend petroleum imports by a factor of 7 to 1’. Other authors report a net energy ratio of 1.38:1 for an average-efficiency corn farm, rising to 2.5:1 for state-of-the-art practices, while cellulosic crops based on current data would have a net energy ratio of 2.62:1 (Lorenz & Morris, 1995). A more detailed life cycle analysis of a soybean-to-biodiesel process for urban buses produced an energy ratio of 3.2 which reduced carbon dioxide emissions by 78% compared to petroleum diesel (Sheehan et al., 1998). The modelling simulations reported in chapter 5 achieve a net energy ratio of 2:1 for ethanol production using biomass as a feedstock, so the modelling results lie within the correct order of magnitude.
A new ethanol-from-biomass plant is being constructed by BC International in Jennings, Louisiana, United States (United States Department of Energy, 1999). This is the first industrial-scale plant of the biomass-to-ethanol process and uses the genetically engineered strain of the organism Escherichia coli developed by the University of Florida. The feedstock for the plant is derived from sugar cane residues, rice hulls, forestry and wood waste and other organic materials. The plant costs US$90 million and produces 25 million gallons of ethanol per year, displacing 500,000 barrels of oil imports annually, creating 350 jobs during the construction phase and 50 full-time jobs for full-time operation. Numerous other smaller ethanol projects are under way in the United States using crop residue, processing waste and domestic refuse. One of the key rationales, particularly close to urban communities, is that the digestion process is a more societally acceptable way of disposing of waste which to date has been burnt or disposed of as landfill.
From a historical context it is interesting to note that in 1935 over 439 million litres of ethanol were used in Europe alone, but that after 1945 ethanol was replaced by petrol of diesel produced by the petrochemical industry (Classen et al., 1999).
Scenarios for the future
A number of wide-reaching scenario studies including biomass fuels have been conducted as part of designing future options for delivering world energy and limiting greenhouse gas emissions. Leemans et al. (1996) concluded that 796 million hectares were required for biomass production and that this would have significant effects on agricultural food production and biodiversity values. They also noted that the effectiveness in reducing greenhouse gas emissions would have to be evaluated in combination with many other environmental, land use and socioeconomic factors. By 2050 in their main scenario analyses (LESS B1), biomass energy was supplying 181 exajoules (1018) of a world total of 574 exajoules (that is, 14%) and by 2100 the contribution had risen to nearly 50%. The carbon dioxide emissions from energy use had declined by 30% in 2050 and by 60% in 2100 compared to 1990 levels. Similar studies by the International Institute for Applied Systems Analysis and the World Energy Council (Nakicenovic et al., 1998) suggested a source of potential land use conflict between food production and biomass land requirements of 610 million hectares in 2050 and 1350 million hectares in the year 2100. The energy productivity of biomass land in these later studies was assumed to be 6 tonnes of oil equivalent per hectare per year by 2050 and 10 tonnes per hectare per year by 2100.
A study by Gielen et al. (1998), which focused on continental Europe using the MARKAL MATTER modelling framework, assessed the possible competition in the use of biomass resources both for energy and material uses. The feasible operation of their scenarios required 22 million hectares of high-yielding crops (eucalyptus, sweet sorghum, miscanthus and poplar) to supply both bioethanol and petrochemical feedstocks. A key tension highlighted in the analysis was the availability of land for biomass production with production targets of 400 to 800 million dry tonnes of biomass per year. The total biomass production per hectare was assumed to be approximately 10 tonnes of dry matter per hectare per year for crops (miscanthus, wheat, poplar and rape) to 23 tonnes per hectare per year for eucalyptus.
A wide range of studies has been undertaken on biomass energy in Sweden where Johansson and Lundqvist (1999) note that the current gross felling of forest has an energy value of 860 PJ per year. They note that Sweden has 2.8 million hectares of arable land, of which 2 million is regarded as essential for food and fodder production, leaving 0.8 million hectares potentially available for biomass energy production. Borjesson (1999), assessing the use of short rotation Salix forest and reed canary grass, noted a wide range of environmental benefits that might flow from converting land from traditional agricultural usage to energy crops. These include decreased water and wind erosion from perennial crop cover, the ability to treat sewage sludge and waste water, the augmentation of biodiversity habitat and the increased banking of below-ground carbon in the energy crop systems.
National economic agenda
The international literature notes a number of benefits in biomass energy systems for the national economy in a more holistic sense. The case of ethanol production from sugar cane in Brazil is a well-documented example. Moreira and Goldemberg (1999) report that US$12.3 billion has been invested in the program in the 15 years 1975 to 1989. Some 174 million cubic metres of ethanol have been produced, displacing the consumption of 141 million cubic metres of gasoline. This has saved US$33 billion of hard currency in fuel imports, which could have risen to US$50 billion if interest rates had been included. This represents 85% of the current reserves in hard currency and 50% of the total government secured external debt. The total annual saving for the country has been US$4.9 billion and ethanol production can be viewed as an effective mechanism to use soft money to control international debt. In addition, the program has created more than 700,000 rural jobs with a modest investment cost of US$20,000 for each job, whereas petrochemical projects in the same region are referenced as costing 20 times more per job to implement.
Being self sufficient in strategic areas such as transportation fuels is an important national policy issue according to Lugar and Woolsey (1999), who note that ‘America’s addiction to middle eastern oil forces dangerous foreign policy compromises, worsens global warming and strengthens unreliable Persian Gulf countries’. The Renewable Fuels Association in the United States reports that its industry will provide a net saving to the Federal Treasury of US$4 billion over the next seven years, create US$60 billion of final demand in the economy, support 55,000 jobs annually, generate more than US$15 billion in farm income and reduce the merchandise trade deficit by US$2 billion a year (Urbanchuk, 1996). Sims (1998) reported that ‘even densely populated Europe has a land surplus of 50 million hectares which could be used to grow energy crops to meet 30–40% of the demand’. He noted that ‘in Bavaria alone over 18,000 jobs use biomass as an energy resource and that 4–5 times more labour is required using bioenergy than when using fossil fuel energy carriers’.
Issues of sustainability
A wide range of sustainability issues relating to the implementation of bioenergy systems at the scale required to provide sound practical and economic alternatives to the fossil fuel system, remain unresolved. Kimmins (1997) suggests that a ‘key issue in sustainability is the retention of foliage and branches on site at the time of harvest…although this material is potential bioenergy, on many sites it should be left to supply soil organisms with an energy source and to supply nutrients’. Evans (1997) suggested four key issues around sustainability as follows: the failure to conserve organic matter between rotations; the physical damage to the site during harvesting; weed problems; and nutrient depletion. He suggested that coppiced systems were particularly prone to these four problems. On the positive side, he noted that many silvicultural systems improved site productivity through drainage and rectification of nutrient imbalances and that tree selection and breeding had much to offer because ‘compared to crop plants the great bulk of forest crops still consist of unselected material from wild populations’.
The cumulative effects literature (Boyle et al., 1997) notes that large-scale perturbations to the current systems such as that proposed by large-scale biomass energy plantation will have effects that: tend to accumulate incrementally; may combine with other effects through space and time; and can result from dissociated and unrelated activities of various land owners. Boyle et al. note the importance for each watershed of integrating the possible effect of the location of road corridors (effects on water flows, sediments, stream habitats, spread of diseases), with the felling and delimbing of trees (plant succession, altered composition of vegetation, new organisms and weeds), with hydrogeologic processes and overall forest management practices.
Finally all biomass-alcohol production systems require a constant source of process water which could be reallocated from agricultural usage. More importantly the conversion of cropland and grassland to forest will have profound effects on the hydrological cycle (Vertessy and Bessard, 1999). It is possible that streamflow from forests in areas with less that 600 mm per year will be negligible since mean annual evapotranspiration is usually less than 650 mm in grasslands, but more than 1300 mm in forests.
Future developments
The literature survey of international developments noted two key areas of importance to the potential of future biomass energy systems. These are the technological developments in the production of both ethanol and methanol which promise significant improvements in yield and improved development of plant production systems which could double the biomass yield per unit area and develop species selection procedures which allow designer ecosystems to be implemented for each soil type, water catchment and farming zone.
The development of ethanol production systems relies on making biomass depolymerisation more rapid and less costly (Himmell et al., 1999) through ‘directed evolution’ of microorganisms to develop industrially hardened strains, able to perform at higher temperatures and without suffering toxicity problems. The evolution of these new fermentation technologies aims to produce not only alcohols but a wide range of commodity products which are currently sourced from crude oil and its derivatives. As well as maximisation of the conversion of cellulose and hemicellulose to sugars for subsequent fermentation, a large technological barrier has existed to the ethanolic conversion of pentoses, the five carbon sugars, (Ogier et al., 1999). Only recently has a University of Florida team used genetic engineering to combine two genes into a ‘portable ethanol production cassette’ (Ingram et al., 1999). This cassette has been integrated into the chromosome of Escherichia coli B to give a strain, KO11, which produces ethanol efficiently from the hexose and pentose sugars present in the polymers of hemicellulose. Ingram et al. (1999) further note that ‘many opportunities remain for the further improvements in these biocatalysts as we proceed toward the development of single organisms that can be used for the efficient fermentation of both hemicellulosic and cellulosic substrates’.
The methanol conversion process is already a well-developed and efficient process but work continues to improve its yield from 40% on a weight-for-weight basis to 50% or more. Hybrid processes such as the HYNOL process (Dong and Steinberg, 1997) combine hydrogasification of biomass and the introduction of a natural gas feedstock, avoiding the need for an expensive oxygen plant and delivering a capital cost of methanol plant considerably cheaper than conventional designs, and an overall methanol cost that is competitive with current United States gasoline prices.
Biomass production systems are still centred on optimising yield from well-known crop and tree plants. Thus late maturing sweet sorghum genotypes are becoming available that are capable of producing 6000 litres of ethanol per hectare (Dolciotti et al., 1998). These genotypes yield between 20 and 27 tonnes per hectare dry weight per year, have three times the sucrose content and have cellulose and lignin contents 40% to 50% lower than standard varieties. Applied in a broad brush manner, this productivity provides sufficient ethanol to run three Australian family sedans for one year, that is, 4 million hectares would support the current Australian private vehicle fleet. This ethanol productivity is similar to the sugar cane system developed over the past 25 years in Brazil where the mean yield is now more than 5000 litres per hectare. Dryland farming in Australia will not be able to match these forage productivities over large areas, but they provide insight into practical productions systems that are possible.
New Zealand tests of coppiced eucalypt plantations in a temperate environment, planted at the equivalent of 2200 stems per hectare, were conducted over a 15-year period and gave mean annual yield that varied from 12 to 34 oven-dry tonnes per hectare per year, depending on the species and management regime (Sims et al., 1999). A limited number of eucalypt species from the trial yielded in excess of 16 tonnes per hectare per year (for example, E. brookerana, E. ovata, E botryoides X saligna, E. botryoides, E. obliqua and E. elata).
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Chapter
2
Biomass fuels from
an Australian
perspective
‘With the uncertainties that
surround the many alternative solutions for the coming shortage of oil, it would
be prudent to keep open all options on liquid fuels for transport as the lead
time for research, development and substantial implementation of new
alternatives are at least 10 to 20 years.’
Alan Stewart et
al.
in the 1979 CSIRO publication
The Potential for Liquid Fuels
from Agriculture and Forestry in Australia.
Abstract
This chapter presents a brief overview of some key Australian studies and activities that relate to the past and recent history of biofuel production in Australia. A wide-reaching set of CSIRO studies in the late 1970s by Alan Stewart and colleagues reminds us that this is not a new issue. Part of the report relating to global warming issues shows that the team was well ahead of its time. There is a considerable amount of activity by the Fuel Ethanol Association of Australia which represents a diverse group of industry partners, university departments and regional communities. Separate in a spatial sense, but related in the context of perennial vegetation cover on landscapes, are the oil mallee developments in Western Australia. These diverse and seemingly separate developments form an important grounding for the analytical chapters that follow.
Overview
Natural resources at a national scale
A soon to be released national report charts the scale of landscape challenges in Australia through the following issues (table 2.1):
• 24 million hectares of Australia’s land are affected by soil acidification and possibly a total of 43 million hectares will be in the future;
• 2.5 million hectares are affected by dryland salinity and possibly a total of 15 million hectares will be in the future;
• 3 million hectares are affected by soil decline and soil loss and possibly a total of 10 million hectares will be in the future;
• one-third of Australia’s inland rivers are in extremely poor health and a further 405 show clear signs of degradation;
• less than 10% of Australia’s original vegetation is left in many areas; and
• many species of mammals, birds, reptiles and amphibians have declining trends.
Table 2.1 Macro indicators of the state of biophysical land, water and biodiversity resources in Australia
Refurbishing and repairing these resources is an immense task. Part of the requirement is to re-establish perennial vegetation over vast areas. It is anticipated that perennial vegetation cover, much of it native Australian species, will:
• deal with the problem of leaky landscapes by increasing water and nutrient use due to ability of deep-rooted plants to tap these resources currently out of reach by annual crop types;
• be permanently on the landscape and so deal with the dynamics of water and nutrient flows;
• be a source of new production methods and opportunities; and
• create new designer ecosystems that can act as expanded habitat for biodiversity resources.
This report aims to explore the synergies that might be created between the requirement to revegetate vast areas of Australian farmlands and the following five factors:
• the possible constraint to domestic petroleum supplies when stocks run low in approximately 25 years and the effect that this might have on external trade indicators as we are forced to import more from abroad;
• the possibility of developing a biofuels industry which aims to gradually replace petroleum-derived products with biomass-based products such as bioalcohols;
• the place that this new industry would have in refurbishing the economic, social and employment opportunities in rural Australia;
• the synergies that this new and large-scale industry might recreate between regional and urban Australia, the scientific and industrial communities and the possibility of radically new products developed for export markets; and
• the place that such an industry has in reducing Australia’s greenhouse gas emissions by introducing a carbon-neutral fuel cycle.
This chapter of the report presents some key Australian literature as a context for the more detailed process and modelling chapters that follow.
Commercial ethanol developments
The Fuel Ethanol Association of Australia (1999) is an industry group given to the realisation of an alcohol fuels industry in Australia. A recent policy paper from the group makes the following points:
• The biophysical and social infrastructure in rural Australia urgently needs new industries that will bring new opportunities to bear upon a complex set of intertwined problems.
• The biomass-ethanol cycle could introduce a carbon-neutral fuels system to help deal with the problems of Australia’s greenhouse gas emissions; 120 million tonnes (that is, 25%) of Australia’s carbon dioxide equivalents are due to the transport cycle.
• Technology advances in the United States by Ford, General Motors and Chrysler have developed ‘flexible fuel vehicles’ with the capacity to use 100% petrol or up to an 85% blend of ethanol and petrol without engine modification.
• There is potential for between 1200 and 1600 bioethanol plants in Australia of different sizes producing between 10 million litres and 100 million litres annually.
• A 1996 study in the Gwydir area of New South Wales indicated the area could support two to three bioethanol plants, with each new plant bringing 159 direct jobs to the area and 600 to 800 indirect jobs.
• Studies quoted from the United States Department of Energy found that 80 cents in every dollar spent on fuel are exported outside the region when oil is used, while the same amount remained in the region when a locally produced biofuel was used.
• A Tasmanian study estimates that the private forests of Tasmania could support 10 bioethanol plants, each with a capacity of 50 million litres per year, creating 3200 direct jobs (320 per plant) and 12,000 to 15,000 indirect jobs. This would produce more than 500 million litres of bioethanol or 65% of the annual usage.
• The 644,000 tonnes of biomass waste produced by Sydney each year could support three bioethanol plants producing in total, approximately 125 million litres of bioethanol per year.
• The development of a bioethanol industry in Australia would require between $60 billion and $90 billion in investment over 20 to 30 years and most of this would be cycled through Australian industry, generating immense returns to skills, capability and export potential.
The report recommended a steady progression to the implementation of a biofuels industry so that 540 million litres would be produced by the year 2005, 1.4 billion litres by 2010, 11 billion litres by 2025 and 85% of all transport fuels from biomass by 2040.
The Stewart study of biomass fuels
The Stewart study of biomass fuels (Stewart, Gartside, Gifford, Nix, Rawlins & Siemon, 1979a, 1979b; Stewart, Hawker, Nix, Rawlins & Williams, 1982) was set in an historical context following a number of oil shocks in the 1970s which, having given cause for alarm in many industrialised countries, promoted the cause of self sufficiency in liquid fuels. Since then, Australian self sufficiency in oil has been maintained so avoiding any cause for immediate concern. In addition, world oil prices have been maintained at relatively low levels with occasional price blips caused by short-term production constraints, heavy demand during northern hemisphere cold snaps and a number of political events such as trade tactics and regional wars. The Stewart report was, however, well ahead of its time when it noted in its summary, ‘if future research shows that rising carbon dioxide levels in the atmosphere are likely to have a deleterious effect on climate, and that the rise is largely due to the combustion of fossil fuels, a rapid move to non-fossil fuels would be necessary, and renewable fuels, which recycle carbon dioxide would be one possibility’.
A number of the key findings of the Stewart report are:
• Some 237 million hectares of land were potentially available for biomass feedstock production. Of that area, 132 million hectares were not available because of terrain. Soil qualities brought the total down to 77 million hectares, of which 51 million were already developed and 26 million were new development.
• There was potential to generate 287 PJ of methanol and 132 PJ of ethanol to give a total of 419 PJ of useable liquid fuel per annum, equal to about half of the liquid fuel requirements of that time.
• This liquid fuel production was possible without altering the food and fibre production from the managed farmlands of that time.
• The 415 PJ net production of biofuels would require a gross production of 630 PJ, requiring 260 conversion plants and providing 60,000 jobs.
• The labour requirements for the study assumed that 100 person years would be needed for both biomass production and harvesting for each petajoule of biofuel produced, and a similar amount would be needed for the conversion process, a total of 200 person years per petajoule.
• A renewable fuel industry would stimulate decentralisation and have important social and defence considerations.
• The cost of production of alcohol fuels from biomass at the time was estimated to be three times that for petroleum, and methanol from coal gasification would also be a much lower cost option.
• Other reports concluded that 13 million hectares of forest plantation could provide 90% of the 1977–78 transport fuel usage.
Oil mallees and the Western Australian wheat belt
The search for deep-rooted plant production systems is attempting to deal with a number of linked problems in Australian farming lands. In particular the deep rooted systems are required to help transpire elevated water tables typical of dryland salinity and to use the perched concentrations of nutrients which are both symptoms typical of the leaky landscape problem. This in turn has led to wide-scale research and development of plantation systems and in particular the oil mallee production system. Key points from Bartle (1999a, 1999b) are:
• There are 18 million hectares of land in the wheat belt of Western Australia, 15 million hectares of which currently does not have a perennial plant option.
• There is wide-scale community concern about, and willingness to act on, the problem of dryland salinity at a landscape scale.
• A range of non-grazing trees and shrubs are available to form the basis of a biomass crop production system.
• Farmers and growers in the Oil Mallee Association have planted more than 12 million oil mallees in the past six years and it is projected 8 million shrubs will be planted in the year 2000.
• For sprouting tree and shrub types, a harvesting regime has been developed which requires a four-year establishment period and then harvests every second year. In more marginal and drier country this regime extends to a five-year establishment period and harvests every three years.
• A detailed investigation of harvesting operations has developed harvesting approaches using sugar cane and forestry equipment that make feasible the development of an efficient and integrated regional biomass flow system within a 40 km to 50 km radius of a central plant.
• The perched water and nutrient resources that form part of the dryland salinity problem can act as a free supplement to the growth of the woody biomass systems allowing a 10-year mining and rehabilitation period before nutrients have to be applied from external sources.
• Biomass yields of 5 tonnes per hectare dry matter per year are feasible and, with spaced plantings of 20% of total land area, 15 million dry tonnes would be available per annum.
• In related work in New South Wales for a trial period over four years, Milthorpe, Hillan and Nicol (1994) and Milthorpe, Brooker, Slee and Nicol (1998) obtained dry matter yields between 5 and 7 tonnes dry matter per hectare per year on an annual harvesting cycle using both oil mallee and blue mallee.
• Control of the dryland salinity problem may require a landscape cover of 80% and this potentially could produce 75 million tonnes per annum, enough to make the State self sufficient in liquid fuels and allow for some export.
• Piloting of an integrated oil mallee processing and electricity cogeneration plant is under development.
Discussion
What the next five chapters do
The logical base for the remainder of this report is constructed through the following themes:
• Chapters 3 and 4 describe the process details of both the ethanol and methanol approach with some examples of energy budgets and costings, and some indications of technological breakthroughs that might be imminent or required.
• Chapter 5 provides a detailed examination of six scenarios for transitions to biofuels and compares them to the base case scenario for a range of indicators of success for the physical economy.
• &n