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CHALLENGES AND
OPPPRTUNITIES OF BIOFUELS PRODUCTION AND USE FROM SOUTHERN
AFRICAN PERSPECTIVE
01/11/2006
By Prof F.D.Yamba, Centre
for Energy, Environment and Engineering, Lusaka
Introduction
Recent events related to global uncertainties in fossil fuel
supplies and high world oil prices, on the one hand, and the
need to reduce poverty, particularly in Africa, on the other
hand, have intensified the motivations to shift to biofuels use.
There is now a growing ‘frenzy’ of interest, especially among
both small-scale and large farmers in Africa, to grow energy
crops from different sources.
This interest is being induced by the realisation that biofuels
can be used for heating, power generation and transport
purposes. Because of this motivation and interest, an excellent
opportunity now exists to propel biofuel production for
sustainable development.
Despite this potential, there exists local, regional and global
challenges which need to be considered.
In some cases, the challenges can be taken advantage of to
enable agricultural biomass, a huge resource in Africa, to be
converted into a variety of biofuels such as ethanol and
biodiesel.
Ethanol can be made directly from sugar-bearing crops, and
indirectly by converting the cellulosic portion of biomass into
sugar [1]. Biodiesel can also be produced from vegetable oil
seeds through use of extraction technologies, and a chemical
process known as “esterification” [2].
Challenges and Opportunities
Global Challenges
From a global perspective, growing concern about the
sustainability of energy supplies (especially in the transport
sector), supply security and the need to take action on climate
have all served to increase interest in biofuels [3]. As regards
security of supply, both biodiesel and ethanol can play an
important role to increase use of domestic resources in the
transport sector, and at the same time address local, regional
and global environmental concerns.
The key driving forces for biofuels in the European Union (EU)
are the Directive for Promotion of Biofuels and Directive of
Fuel Quality [3, 4]. The former, which requires member states to
set indicative targets for biofuels sales in 2005 (2 per cent)
and 2010 (5.7 per cent) is motivated by the need to cut
greenhouse gases and increase energy security by reducing
dependence on imported fuels [3]. As a result of this directive,
it is estimated that a market demand of 10.5 billion litres of
biofuels with be created [4].
As regards meeting the Directive on Fuels Quality, biodiesel has
useful properties as it is known to release fewer solid
particles than conventional diesel, and contain no sulphur and
release no SO2, which contributes to acid rain. Biodiesel also
has rapid biodegradability qualities, low toxicity to people and
the environment, and a high flashpoint. Ethanol, on the other
hand, is “CO2 neutral” because the carbon diode released during
combustion is absorbed from the atmosphere by the next
generation of crops. It can also compete with methyl-tertio-butyl-ether
(MTBE) as an octane enhancer in addition to having less impact
on the environment (both air and ground), and being less harmful
to health.
Due to limited land availability, and relatively high cost of
the feedstock rape seed, it is unlikely the anticipated demand
of 10.5 billion litres of biofuels in the EU will be met by
domestic supply. This market is of significance to creating a
biofuels industry in Africa.
National Regional Perspectives
Apart from high world petroleum prices, two other factors
beginning to have an impact on biofuels development in Southern
Africa are the EU Preferential Trade Agreement Sugar Reform, and
the Africa Dakar Declaration on replacement of lead as an octane
enhancer for gasoline fuels. The Dakar Declaration, which came
into effect at the end of 2005, requires substitution of lead as
an octane enhancer.
Some refineries in the region as a short term measure have
resorted to use of MMT – a manganese based additive. But MMT
also raises different concerns over potential health risks, and
is thus viewed as controversial [5]. Another approach is for
refineries to manufacture high-octane gasoline through use of
catalytic reforming units. For many refineries in Africa, this
will require upgrades, and large capital outlays, which will not
be affordable [5]. In the medium-term, most countries in the
region are seriously considering use of ethanol as a substitute
for both lead and MMT.
The recent announcement under the EU Sugar Reform to reduce the
EU’s intervention price by 36.0 per cent will have an impact on
the competitiveness of sugar industries within the African,
Carribean and Pacific regions (ACP). For them to survive this
will require innovative diversification plans into other core
products such as ethanol and co-generation.
Production Technologies/ Processes and Economics
Ethanol
Various technology configurations are available on the market
for ethanol production. Their concepts are largely influenced by
the feedstocks used and composition, whether anhydrous or
hydrous. The former is suitable for production of fuel as a
transport fuel. The type of technology used can either be
annexed or autonomous. For Southern Africa, annexed distillation
has the greatest potential, in view of the structure of the
sugar industry.
Ethanol can be obtained from many different feedstocks, in fact
from any sugar-containing raw material. Feedstocks can be
classified into three main groups:
(i) Sugars: (i.e. sugarcane, molasses, fruits, etc) that can be
converted to ethanol through fermentation and distillation
(ii) Starches: (i.e. grains like maize, root crops like
cassava), which must be first be hydrolysed to fermentable
sugars
(iii) Cellulose (i.e. woody material, agricultural waste, black
liquor from pulp and paper which must be converted to sugars by
action of mineral acids
From an economic point of view, very few materials can seriously
be considered as feedsock. And from Southern Africa’s
perspective, sugarcane and sweet sorghum offer promising
feedstocks (examples: Brazil, Malawi, India, Kenya and Zimbabwe)
[6]. Quantities of ethanol and feedstock required depend on the
demand, which in turn is influenced by the level of blending (5
per cent, 10 per cent, 15 per cent). At present, most of the
ethanol is produced from cane molasses, which, however, has
limited availability, being a by-product of sugar factories and
has limitations on waste water control.
In view of such limitations, there is a need to exploit new
agro-based feedstocks. For such feedstocks to be attractive,
they need to have the following characteristics: sugar-bearing,
remunerative for the farmers, low cultivation costs, viable for
alcohol production and giving zero discharge of waste water.
Taking into account the climate and soils in southern Africa,
one such feedstock that can be effectively exploited is sweet
sorghum. It has the following characteristics:
• Sugar-bearing feedstock
• Short cycle crop –3.5 months
• Can be grown across warm climate regions
• Easier to grow and handle (vis-ŕ-vis sugar cane)
• Low cultivation costs
• Known to farmers – robust crop- practices similar to
sugarcane
• Gives fodder for cattle
• Gives bagasse similar to sugarcane – energy for
distilleries
Biodiesel
The production of biodiesel is well known. Three basic routes to
diesel production from oils and fats exist, and are listed
below:
• Base catalysed transesterification of the oil with alcohol;
• Direct acid catalysed esterification of the oil with
methanol;
• Conversion of the oil to fatty acids, and then to alkyl esters
with acid catalysts.
The most commonly used and most economical process is called
the base catalysed esterification of fat/oil with methanol,
typically referred to as “the methyl ester process”, due to the
following [7]:
• Low temperature (65.6oC) and pressure (20psi) processing;
• High conversion (98%) with minimal side reactions and
reaction time;
• Direct conversion to methyl ester with no intermediate
steps;
• Exotic materials for construction are not necessary.
The amount of feedstock requirement in the region to produce
biodiesel depends on the amount of diesel consumed and the
percentage of blending. Traditionally, conventional major
feedstocks for the “methyl ester process” are cotton seed oil,
soybean and peanut oil.
Another suitable feedstock for the “methyl ester process”, which
can be used and grown in southern Africa, is Jatropha,
attractive in view of uncertainty of conventional feedstocks and
also to avoid conflict between energy and food, since it is a
non-edible oil.
The characteristics of Jatropha that make it superior to
conventional feedstock are listed below [8]:
• Jatropha curcas L. belongs to the family euphorbiaceae;
• Growing period = approx. 100 days;
• Drought resistant;
• Grows on well – drained soils with good aeration, and is
well adapted to marginal soils with low nutrient content;
• Yield ranging between 5 to 10 tonnes per hectare;
• Oil content = 40 per cent;
• Grows as a shrub, and needs no fertilizer.
Economics
Ethanol
Given in table 1 is a comparison of local ethanol prices and
other international prices.
Prices obtained from local production compare favourably with
Brazil, and are more competitive than the USA. depending on the
feedstock.
Table 1: Comparison of Local Ethanol Prices and Other
International Producers
Country Ethanol Price (Gasoline Equivalent)
US cents Feedstock
Southern Africa 20-25 Molasses
Sweet sorghum juice
Brazil 25-30 Molasses
Sugarcane juice
USA 40-50 Corn
EU 50-90 Cellulose
Biodiesel
As in the case of ethanol, biodiesel prices are equally
comparative with other producers in Europe as shown in table 2.
Table 2: Comparison of Biodiesel Prices
Country Biodiesel Price (diesel equivalent), US cents
Feedstock
Southern Africa 30-35 Jatropha
EU 40-80 Rape seed
Soy
EU 25 Waste oil
Conclusions
Southern Africa has great potential to greatly benefit from the
use of its natural resource endowment base to produce biofuels,
and if such projects are implemented they will go a long way to
achieving a sustainable energy path, and contribute
significantly to poverty reduction through creation of numerous
jobs from agriculture, processing and marketing.
REFERENCES
1. Deborah W. Cornland, Francis Yamba, Francis X. Johnson, Et’
al (2001): Sugar Resources for Sustainable Development: A Case
Study in Luena, Zambia, Stockholm Environment Institute, Sweden,
ISBN-91-88714-71-3.
2. National Biodiesel Board (2003): www.biodiesel.org.
3. Larsen, H. Kossman J., and Petersen, L. S: New and Emerging
Bioenergy Technologies, Risoe Energy Report 2, Riso R-1430 (EN).
ISBN 87-550-3261-5.
4. Wood, P.: Out of Africa, Could Jatropha Vegetable Oil be
Europes’s Biodiesel Feedstock? Reforms – July/August 2005. 1471
0 846105 – 2005. Eisevier Ltd, 2005.
5. Yamba, F. D. and Matsika, E. (2004): “Factors and Barriers
Influencing the Transfer and Diffusion of Biofuels Producing
Based Technologies With Particular Reference to Southern
Africa”, presented at the Industrial Technology Development,
Transfer and Diffusion IPCC Expert Meeting, Tokyo, Japan, 21-23
September 2004.
6. Yamba, F. D. (2003): CARENSA Working Paper : Benefits From
Sugarcane Co-Products And Policy Issues, Durban.
7. Shumakar, G. A, McKissick, J., Doherty, B. (2002): A Study on
the Feasibility of Biodiesel Production in Georgia.
8. AREED (2003): Feasibility Study on the Production of
Biodiesel in Chavuma, Western Province, Zambia.
Date: q406
