Transport fuels from biomass

These are the notes from a talk Barney Foran (Futurist- Visiting Fellow at Charles Sturt University). I'm seeking any comment. The notes refer to Australia

Transport Fuels from Biomass
Barney Foran
Institute of Land Water and Society
Charles Sturt University, Albury

Summary
Converting plant material or biomass to liquid transport fuels offers three important advantages to the Australian economy. Firstly, if designed in an holistic context, it can be nearly carbon neutral for the dominant transport modes. Secondly, if based on wood biomass, the extensive areas required (upwards of 50 million hectares by 2050) will help refurbish agricultural communities with climate resilient products, add landscape texture and biodiversity, and generate a wide range of ecosystem services. Thirdly, it will markedly improve transport fuel security and reduce the balance of payments implications for the peaking of ?'cheap traditional oil' in the next decade.

Biomass Fuels
Transport fuels made from plant products (biofuels, biomass-based fuel cycles) are undergoing a rapid production expansion worldwide driven by three issues: fuels security in the face of possible declines in oil availability, the need to reduce the carbon intensity of transport because of global climate change, and finally the opportunity for increased farm profits due to flat product prices in a domestic markets. Australian policy and industrial activity mimics in part the developed world scene, but current lacks the market stimulus driven by the aggressive targets set in the European Union, Brazil and the USA.

Currently the most common forms of transport biofuels are ethanol made from grain starch or sugar cane juice, and biodiesel made from waste fats or oil seeds. There is little doubt that the Brazilian ethanol system is extremely productive with efficient well scaled industrial plants processing highly productive sugar cane crops, grown on good soils in a sub tropical climate. Less obvious are the life cycle advantages of the corn to ethanol system currently dominating the production system in the corn belt of the USA. Biodiesel systems which process waste cooking oils and animal tallows are defensible as they turn difficult waste into a safe and useable product with useful by-products such as glycerine. Less defensible are oil palm systems where virgin rainforest is felled to provide a land base. Oil seed systems based on canola and soybean are somewhere in between these two bounds.

The biofuel of choice here is wood alcohol or methanol. It is currently made from natural gas feedstock, but was originally synthesised from wood. It is the simplest of the alcohols, it can be used in a variety of engine types, it combusts cleanly and has relatively low emissions in well tuned engines. It is widely used as a chemical feedstock and may require closed delivery systems similar to LPG since frequent exposure may penetrate through skin. Alternatively, it may be hydrated to produce the benign di-methyl-ether gas, an ideal substitute for diesel. Methanol made from wood in a well organised and structured production system is nearly carbon neutral producing about 20 grams of carbon dioxide per vehicle kilometre compared to the current range of 140-180 grams per kilometre for the Australian vehicle fleet.

Many first generation biofuels give limited advantages from a lifecycle perspective with only small reductions in greenhouse gas emissions compared to traditional fossil fuels. Transforming grain starch or sugar juice to ethanol is industrially tractable, but gives only small energy profits (total useable energy out, divided by total energy in). The key problem is the small amount of total crop production used in the process and the complexity of the energy transformation process. The ethanol fuel cycle will improve when the cellulose or whole-of-plant systems enter production. By comparison, the gasification and synthesis systems used to produce methanol from wood are simpler, they can be used in continuous rather than batch mode and show much higher energy profits

The drive trains of vehicles will undoubtedly evolve over the next 50 years, driven partly by fuel availability. The ?'methanol from wood' system covers three practical possibilities reasonably well. Firstly, traditional internal combustion engines run cleanly and well on methanol, provided that ignition and compression are adjusted and components are methanol proofed. Secondly, the hydrated derivative of methanol di-methyl-ether or DME, is an ideal diesel substitute and would be especially effective if the personal vehicle fleet was powered by new highly efficient European diesel engines. Thirdly, methanol is an ideal ?'hydrogen carrier' for the expected development of fuel cell powered vehicles that are now under test, and expected to be commonplace around 2020.

To underpin an Australian economy which grows at the rates anticipated by Treasury's Intergenerational Report will require upwards of 50 million hectares of woody biomass landscape by 2050. The planting procedures tested, progressively step through the currently developed agricultural regions using no more than 10% each of crop-land, pasture-land and rough-land for each region. This process introduces a new land use but maintains current production levels for traditional product lines. The wood systems mimic those proven currently in each area both in species used and lengths of rotation. In low rainfall regions, a ?'generic' mallee system proven in Western Australia is used. However the recent investment into species selection particularly for Acacia and Eucalyptus will allow productive lines from locally occurring species to be planted in each region in the future. Thus a new ?'synthetic' biodiversity will be established.

We know enough about landscape scale and process to apply planning schemes where key habitats could be managed as core biodiversity areas, while the production areas could be harvested on a range of timescales driven by production schedules, and guided by long term environmental and conservation requirements. The planting scheme gives around 30% of each region established to shrubs and trees which meets the generally agreed minimum threshold where natural processes can again begin to function at the landscape scale. While this will not allow pre-European biological diversity to flourish, it nevertheless offers a climate-resilient production system which adds a new cash flow to current crop and animal systems. Once established, biomass landscapes could complement new federal schemes for environmental stewardship payments. These systems add texture to Australian farms and catalyse the landscape refurbishment away from today's tamed status that poses so many physical challenges.

Tree and shrub plantings of this scale will not be without their problems particularly for bush fires, water runoff and possible weediness. The prospect for hotter and drier times ahead could increase the fire proneness of farming landscapes. However on each farm they will exist in a mosaic with current uses where thoughtful planning will provide buffers and firebreaks. Additionally they will be a valued source of cash flow and not just ?'scrub where fires come from'. Avoiding the negative runoff impacts of planting key catchment areas will be a core planning objective, as will ensuring that species selections for each region are well screened for potential weediness. Balancing these negatives is the potential that once established, the biomass-based fuel system will provide a climate resilient cash flow. Species such as mallees can be harvested at anytime and re-sprout from their underground storage organ. Compared to crops, woody plants are deep rooted with greater access to nutrients and soil water. They grow when rains come and survive most droughts.

An important complement to biomass-based fuel systems will be the development of carbon-rich soils. South American studies have examined man-made ?'Terra Preta' soils which supported advanced civilisations up to 1,500 years ago. Their key feature is a deep carbon-rich humus layer developed by the deliberate incorporation of charcoal-like materials. The charcoal materials give high biological reactivity with good water and nutrient availability. Typically, they produce at twice the level of unmodified adjacent soils. Fuel processing ?'energy-plexes' will produce these carbon compounds as by-products through fast pyrolysis processes. After incorporation into production soils, these carbon compounds are physically stable for many centuries and can be used for audited carbon sequestration schemes. By comparison, forest sequestration provides only a short term and partial solution.

The social refurbishment provided by an additional land-based set of products will be immense. It will be year long, relatively inelastic in economic terms (i.e. the cities will always require transport fuels), and require a wide range of skills from basic machinery operators, through building and fabrication to advanced process chemistry. Projections of regional demography suggest there will be enough people but that specific skills will require assured development over the next 50 years

The transition from oil-based to biomass-based transport fuels must be fluently integrated with the transition to renewable electricity to achieve large overall reduction in carbon dioxide emissions. Current modelling studies show that combining 20% contributions to electricity supply each from wind, solar photovoltaic, solar thermal and biomass with 90% of oil dependence from wood-based methanol, gives a long run economic performance slightly below the current fossil-based system. This full renewables transition reduces carbon dioxide emissions by 60% out to 2050.

Biomass-based systems of the scale envisaged here present regional planning challenges particularly in transport and water catchments. For transport, it makes little sense in an energy lifecycle and economic sense to transport bulk biomass more than 30-40 kilometres to a processing plant. Thus the logistics serving the 500 or more local processing plants envisaged by 2050 will have to be well done to avoid clogging up normal transport arteries and provoking social tension. It is possible however to have ?'concentrating' centres where bio-oil from fast pyrolysis can be fed into pipelines in a way analogous to ?'juicing' facilities in the sugar cane industry. The interaction of extensive wood planting with runoff from water catchments is another potential issue. It will require good social and political processes to be integrated with fine scale catchment management analysis.

Getting these biomass-based systems running and optimised in rural Australia offers many opportunities for global commerce and international aid. Knowing how to fluently plant, harvest, transport, transform and market the wide range of products from a biomass-energy economy offers the prospect for a buoyant export industry based on manufactures and services. The skills base of engineering and process chemistry will stimulate a domestic green manufacturing boom, the knowledge from which can be easily exported to both developed and developing countries. Developing right-sized bioenergy systems for our near neighbours will enable them to reach the levels of energy services required for equitable human development. Stand alone energy systems will stimulate local economic activity and employment so releasing funds for education and health.

There are many valid criticisms of a biomass-based economy, most importantly those that focus on narrow measures of economic efficiency. It is a thermodynamic reality that the systems described here can never be as economically productive as those developed over the past three centuries and based on fossil fuels. Coal, oil and natural gas are after all, distilled and concentrated products derived from large accumulations of plant material from previous geological eras. Transforming biomass grown today into transport fuel can never have the same energy density and ease of acquisition as that offered by large oil and coal fields. Thus transport fuels and electricity produced from biomass must inevitably cost more than their fossil equivalents. Carbon taxes will impose this reality anyway by placing a market disincentive on what are today free emissions of carbon dioxide pollution. The arguments for biomass based systems rely on their carbon neutrality, their domesticity and widespread landscape and social refurbishment for rural and regional Australia.

Today, the full range of household consumption activities for the average Australian citizen is directly responsible for about 19 tonnes of carbon dioxide emissions. Emissions from exports and government are additional to this 19 tonnes. A biomass based economy will require about two hectares of land per person to be managed for liquid fuel production, some biomass electricity and some carbon offsets. Less land per person would be required if expanding personal consumption and rates of economic growth were reined in. The opportunities posed here offer a transformational future for Australians where we are able to break the mould of the current high emission lifestyles and the fossil-based structure of the economy. There are many market-based opportunities for citizens to own their biomass land and thus become part of a carbon-active lifestyle where personal investment decisions help to refurbish Australia's heartlands.

Barney Foran