Category Archives: Second Generation Biofuels and Biomass

Energy Density: Cigajoules per Tonne

What is the price of biomass? Biomass buyers, such as utilities and power plants, are only interested in the energy density or "calorific value” of biomass — how much heating power the biomass can deliver. It is the quantity of heat produced by the complete combustion of a given mass of a fuel, usually expressed in joules per kilogram or gigajoules per tonne. When the energy content is higher than average, the biomass value is higher; when the laboratory tests show a lower calorific value, the biomass is worth less and the price goes down. Biomass traders are often not interested if the feedstock is palm kernel shells or woodchips — all they want to know is the “gigajoule per tonne” number or how much "energy density” are they

Table 8.3 Statistical comparison of agripellets, lignite, and coal.

Properties

Agripellets

Lignite

Coal

Gross calorific value (kcal/kg)

4200

2800

5200

Net calorific value (kcal/kg)

3952

2668

4980

Volatile matter (%)

70

24

30

Fixed carbon (%)

16

29

47

Ash (%)

<10

21

14

Moisture (%)

<10

26

9

Carbon dioxide emission

neutral

1.78

166

(tonnes CO2 carbon per ton of fuel) Sulfur (%)

0.07

1.4

0.7

Bulk density (kg/m3)

650

650-780

720-850

Source: Brazilian Association of Industry Biomass and Renewable Energy — Brazil Status Report Biopellets, 2012.

buying or selling. These numbers are made available during laboratory tests during the port of loading and port of offloading, when biomass is shipped to its final destination.

Some average calorific values of different types of biomass, biofuels, and coal (in GJ/tonne) are:

• Wood fuel (bone dry): 18-22

• Wood fuel (20% moisture): 15

• Palm kernel shells: 15-17

• Wood pellets: 16.8

• Wood chips (depending on moisture level): 9.5-14.3

• Agricultural residues: 10-17

• Charcoal: 30

• Ethanol: 26.7

• Biodiesel: 37.8

• Coal (bituminous): 27-30

• Coal (lignite): 15-19

Unfortunately the calorific value of fossil fuels is about 3 times higher than biomass. So if you heat a building with biomass only, you need 3 times more biomass feedstock "in bulk” for the same energy content as heating oil.

If you evaluate biomass, you must check the key components:

• Bulk density (kg/m3)

• Mass (kg)

• Moisture content (%): more moisture means less value

• Energy density (kWh/kg or GJ/tonne).

8.9

Subsidies

The Ministry of Finance in China recently announced flexible subsidies and financial support for farmers who plant energy crops. The subsidies will be tied to the price of crude oil. When oil prices go down substantially and biofuel prices in tandem, farmers would loose money. Farmers will receive up to $400 per hectare planted with forest products for biofuels and up to $360 per hectare for crops planted for biofuels.

China has announced the abandonment of ethanol projects that use foodstocks, excepting existing plants and those already under construction. China is the third — largest ethanol producer, behind Brazil and the United States.

The expansion takes place under the auspices of China’s Green Poverty in Reduc­tion program (www. undp. org. cn/modules), which was launched in 2006. The $8.5- billion project is a joint venture between the UNDP, China’s Ministry of Science and Technology, and the Ministry of Commerce. The project aims to develop biofuels and other ecofriendly projects in China’s poorer western provinces. The previously mentioned Jatropha nurseries in Hainan are also cultivated under a UNDP program.

The Chinese government has implemented various favorable policies and pro­vides incentives to agricultural companies. Jatropha plantations qualify for gov­ernment grants from China’s State Forestry Administration, State Administration of Taxation, National Development and Reform Commission, Ministry of Agri­culture, and Ministry of Finance.

12.10.9

Demographics: India and China

I expect India to overtake China in population around 2030. In 20 years India will have 1.5 billion inhabitants and China as well. These 3 billion people will be 40% of the global population! Thus, the commodity consumption from these two countries alone will be staggering (Figure 1.8).

Still the question remains: we now have 7 billion people on Mother Earth. The global population between 1987 and 1998 increased from 4 to 5 billion people. Why did commodity prices not increase simultaneously? Prices of commodities — in real terms, adjusted for inflation — have not risen dramatically. Why not? It just shows that prices are sensitive to consumption and in recessionary times like in the 1990s less consumption means lower commodity prices. Thus, the key with commodity prices is personal income, personal wealth, and jobless rates — all

China

image9

Figure 1.8 India’s population will overtake that of China by 2030: India 1.5 billion + China 1.5 billion = 40% of the global population. Source: Mother Earth Investments AG Research.

1.9 Oil, and First — and Second-Generation Biofuels

Подпись: 13factors that determine commodity consumption. If indeed the standard of living of the poorest of the 7 billion people would improve, we would see a substantial increase in commodity prices.

1.9

Storage

Jatropha seeds are oily and can be stored for 6 months without loosing their oil content. If seeds are stored longer, the oil content will diminish. Research on viability of Jatropha seeds shows a clear decrease depending on the length of storage. Seeds older than 15 months show at least a 50% lower oil content.

J. curcas grows best on well-drained soils (preferably pH 6-9) with good aeration. The plant can also grow on marginal soils with low nutrient content, but the oil content will most probably be lower. Therefore, it is imperative to test the soil before a Jatropha plantation is started.

J. curcas grows well with more than 600 mm rainfall per year and it can with­stand long periods of drought. The plant sheds its leaves during a prolonged dry season. The plants also survive too much rain. I have seen a nursery in Hainan that was affected by a tornado. After the storm, the nursery was as flat as a pancake and I remember how sad the farmers were, thinking the crop would be lost. Two months later, however, all the plants were standing happily erect again.

Ideal temperatures should average 20-30°C (68-90°F). Jatropha can, however, withstand a very light frost for 1-2 days, which causes it to lose all its leaves and may produce a sharp decline in seed yield. In Florida, less and less oranges are growing due to prolonged frost. Thus, I think growing Jatropha in Florida would be a risky business.

3.1.21

Genetic improvement ofJ. curcas

Grown in the proper environments with good agronomic practices, J. curcas can be produced profitably today with high yields and low input costs. With the right team, tools, and genetic diversity, the possibilities to push this species even further in the direction of greater yields with increasingly lower inputs are extremely promising. Jatropha is what is referred to as an undomesticated crop, meaning it has not undergone intensive selection and breeding to optimize those traits that could expand its productivity as a renewable fuel crop. While many food crops such as corn have been bred and domesticated for thousands of years, Jatropha is at a very early stage in the domestication process. Jatropha has many qualities that make it ripe for leaps in improvement:

• An undomesticated species.

• A fast-growing perennial shrub or small tree.

• A generation time of about 9 months.

• Produces separate male and female flowers.

• Can be readily propagated by cuttings.

The privately held company SG Biofuels (www. sgfuel. com) has established a Jatropha Genetic Resource Center (GRC) to further accelerate profitable, large — scale production of Jatropha as a low-cost, sustainable source of feedstock for biofuel. With research sites in San Diego and several Latin American countries,

SG Biofuels and its GRC claims to have the largest, most genetically diverse library of Jatropha genetic material in the world. The GRC enables the company’s efforts to drive genetic improvements that will enhance yield, improve agronomic prac­tices, and broaden the effective growing range of this promising subtropical crop.

This germplasm foundation, in combination with modern biotechnological advances and practices, is providing the platform for significant improvements in this renewable fuel crop.

The scientific team at SG Biofuels has already identified many strains whose characteristics suggest they have only scratched the surface for the production cap­abilities of Jatropha. The GRC allows the company to identify commercially valuable traits, and continue to enhance them through genetic and scientific programs. Through its GRC, SG Biofuels has begun evaluating thousands of diverse accessions of Jatropha obtained from a range of geographical and climatic conditions.

Dr. Robert Schmidt oversees efforts at the company’s San Diego and Latin American research sites. Research efforts include selection and breeding, and the company has generated hybrids among genetically distinct lines to address such issues as yield, cold tolerance, and resistance to insect pests.

Through additional genetic improvements and breeding, a range of opportu­nities exist to improve Jatropha’s oil yield and develop improved strains, including those that can further enhance production in the colder climates of the United States and other nations.

Подпись: References 1 Heller, J. (1996) The Physic Nut - Jatropha Curcas L. Promoting the Conservation and Use of Underutilized and Neglected Crops. Institute of Plant Genetics and Crop Plant Research, Gatersleben/International Plant Genetic Resources Institute, Rome. 2 Ginting, L. and Pye, O. (2011) Resisting agribusiness development: the Merauke integrated food and energy estate in West Papua, Indonesia. Paper presented at the International Conference on Global Land Grabbing, 6-8 April, University of Sussex. 3 Staples, G.W., Herbst, D.R., and Imada, C.T. (2000) A Survey ofInvasive or
Подпись: Potential Invasive Cultivated plants in Hawaii. Issue 65 of Bishop Museum Occasional Papers. Bishop Museum Press, Honolulu. 4 Van Aarde, R. (2005) The ecological implications ofthe establishment of commercial Jatropha curcas L. plantations in South Africa. Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria. 5 Hill, A., Kurki, A., and Morris, M. (2006) Biodiesel: The Sustainability Dimensions, National Center for Appropriate Technology, Butte, MT, pp. 4-5.

With proper site selection and agronomic practices, oil yields of 200-300 gallons of extractable oil per acre are realistic today with likely improvement in yields in the range of 50-100% anticipated over the next several years.

Guatemala

Several developments unfolded recently in global Jatropha commercialization efforts. In the Central American country of Guatemala, the Roundtable on Sustainable Biofuels is working with SG Biofuels (www. sgfuel. com) to develop sustainability standards for Jatropha farming.

In 2009, SG Biofuels established a community farming initiative in Guatemala with 385 farmers working 1400 acres of marginalized land. While many Jatropha business models have failed in recent years, Jatropha has not. The plant did not fail — many businesses did.

"SG Biofuels wanted to find a community to partner with, not take over. SG Biofuels worked with community leaders, gave them seedlings, donated fer­tilizer, technical support, and advice. SG Biofuels contracted with the farmers for all of their production. SG Biofuels emphasized that the importance of the con­tract cannot be understated… It helps create rural entrepreneurship,” CEO Haney has said.

Haney pointed out that in places outside the United States, some land is community-owned, not privately held — a foreign concept to most Americans. Some of this land, especially in the subtropics, was once rainforest, cut down long ago for cattle pastures, but after years of intense grazing the land has become stressed and marginalized. "It is abandoned pastureland so when a company like ours can come in with a new technology like this — the community sees it as a very good economic opportunity,” Haney said. Contracts signed by the community farmers lock in their profit and take away the execution risk. According to Haney, "There is a floor in the off-take agreement, it’s indexed to a couple of different factors”.

6.7

Indirect Land-Use Change

The basic assumption with biofuels is that plants absorb as much carbon dioxide while growing as they release when burnt in an engine. If you use them as a fuel, their net impact on the climate is close to zero, except for emissions from farming machinery and fertilizers.

However, this does not take into account a relatively new concept that scientists dryly call "indirect land-use change.” Put simply, if you take a field planted with grain and switch that crop to something that can be used to make a biofuel, then somebody will go hungry unless the missing grain is grown elsewhere or farming yields are massively improved.

The rush to biofuels means the quantities of land needed are huge, if all renewable fuels would come from plantations. Satisfying the demand of the European Union alone will require an additional 4.5 million hectares of land by 2020, based on an average of 15 of the studies for the Commission. That is an area roughly equal to Denmark.

This leads to a number of open questions:

• What gives Europe the right to lecture developing countries on how they should use their land?

• Why impose tighter standards for the vegetable oils that are burnt in cars than those that are used in the kitchen?

• How do we account for waste animal fats that are as likely to end up in cosmetics and beauty products as they are in the fuel tank of a car?

10.6

Biofuels and Public Health

Brazil’s carbon dioxide emissions have been greatly reduced with the initiation of sugarcane plantations. Since 2003, Brazil’s use of sugarcane ethanol has reduced that country’s emissions of carbon dioxide by 122 million tonnes. That is com­parable to planting and maintaining 873 million trees for 20 years. These low — carbon benefits from sugarcane will expand with the development of high-tech products on a commercial scale, such as cellulosic ethanol, bioplastics, and biohydrocarbons.

13.16

Cautionary Notes

• Availability. The technologies are in development and the supply of second- generation biofuels is not yet available on a big commercial scale.

• Financing. Capital is hard to come by in this market.

• Sugar prices. They are very volatile and are heading seriously north. In 1999, sugar was trading at 5.5 cents per pound, in January 2011: 34 cents a pound. April 2012: 24 cents a pound. Due to its function as a feedstock for biokerosene I think sugar can once again double in price.

• Linkage of the sugar price to oil. These days, commodities like palm oil are linked to petroleum. Sugar has resisted the trend — when oil prices crashed 75% in 2008, sugar rose for the year. However, if oil and sugar become linked, it will make it difficult for processors to make money unless the spread is sufficient, retarding the prospect of financing.

13.17

Biomass

Renewable resources of energy are constantly replenished and will never run out.

Biomass can be transformed into liquid fuels for transportation, called biofuels. The use of biofuels will reduce pollution and reduce a country’s dependence on non-renewable oil.

image13

Figure 2.2 Feedstock for biofuels (yield per hectare in liters). Source: Agriculture and Agri­Food Canada; www4.agr. gc. ca.

Biomass is material that comes from plants. Organic waste is also considered to be biomass, because it began as plant matter. Plants use the light energy from the sun to convert water and carbon dioxide to sugars that can be stored, through a process called photosynthesis. Some plants, like sugarcane and sugarbeet, store the energy as simple sugars. Other plants store the energy as more complex sugars, called starches. These plants include grains like corn and are also used for food. The problem here is that sugar and corn are used for food as well.

Another type of plant matter, called cellulosic biomass, is made up of very complex sugar polymers and is not generally used as a food source. This type of biomass is under consideration as a feedstock for bioethanol production. Specific feedstocks under consideration include:

• Agricultural residues: leftover material from crops, such as the stalks, leaves, and husks of corn plants. The residue from sugarcane, called bagasse, is becoming a very important biomass. Other types of plant mass traded as biomass are tea leaves, coconut shelves, olive oil seedcake, and palm kernel shells.

• Forestry waste (chips and sawdust from lumber mills, dead trees, and tree branches).

• Municipal solid waste (household garbage and paper products).

• Food processing, feedlot waste, and other industrial wastes.

• Energy crops (fast-growing trees and grasses) developed just for this purpose like Jatropha and Camelina. Hybrid eucalyptus trees and Miscanthus or Elephantgrass plantations are also being developed and sold as biofuel and biomass. A basic requirement for the production of grass-based biofuels is a sufficiently large area that permits the economic production ofthis raw material. The use of marginal land does not necessarily stand in competition with worldwide food production, as is often feared. Grass for biofuels can thus also be grown on soils and in climates that are entirely unsuitable for the cultivation of food crops. More than half of today’s global demand for liquid fuels could be covered by biofuels produced from raw materials grown in such areas.

Cellulose is the most common form of carbon in biomass, accounting for 40­60% by weight of the biomass, depending on the biomass source. It is a complex sugar polymer (“polysaccharide”).

Lignin is a complex polymer that provides structural integrity in plants. It makes up 10-24% by weight of biomass. It remains as residual material after the sugars in the biomass have been converted to ethanol. It contains a lot of energy, and can be burned to produce steam and electricity for the biomass-to-ethanol process.

2.6

Biochar

The biofuel concept has been that if you just burn plant materials, you put out a lot of bad pollutants. However, if you heat the materials in a container without oxygen (“pyrolysis”), you leave most of the carbon as “biochar,” which makes an excellent soil additive (in fact Amazon Indians built up rich soils over hundreds of years using biochar). The gas that is given off by pyrolysis can be processed into clean­burning fuel.

3.2.2.1 Woodpellets

Jatropha fruit shells have a high fuel heat value of 4000 kcal/kg and this is similar to coal. Jatropha fruit shells can be dried and compressed into woodpellets in combination with woodchips — a very environmentally friendly fuel.

3.2.2.2 Polyol

If you buy a fridge, a PC, a notebook, a television, or prepacked meat in a super­market the product is packed in styrofoam. This is the white packaging material that makes an impossible squeaky noise if you scratch it with your fingernails! Styrofoam is made of oil, it is not degradable, and it is patented by the American chemical giant DuPont. Out of Jatropha you can produce polyol, which has the same properties as styrofoam, but it is biodegradable! Thus, anyone who produces 1 million tonnes of polyol will be made very welcomed by the Sony’s, Mitsubishi’s, and Apples’ of this world to offer them green packaging. Polyol can be used in the packaging and insulation industry.