22.214.171.124 Fuel Switching
In general not much attention is paid to fuel switching in the manufacturing
industry. Fuel choice to a large extent is sector dependent (coal for dominant
processes in the iron and steel industry, oil products in large sectors in the
chemical industry). Nevertheless, there seems to be some potential. This may
be illustrated by the figures presented in Table 3.20
where per sector the average carbon intensity of fuels used in
industry is compared to the country with the lowest carbon intensity. This indicates
that fuel switching within fossil fuels can reduce CO2 emissions
by 10%20%. However, it is not clear whether the switch is feasible in
practical situations, or what the costs are. However, there are specific options
that combine fuel switching with energy efficiency improvement. Examples are:
the replacement of oil- and coal-fired boilers by natural-gas fired combined
heat and power (CHP) plant; the replacement of oil-based partial oxidation processes
for ammonia production by natural-gas based steam reforming; and the replacement
of coal-based blast furnaces for iron production by natural-gas based direct
reduction. Daniëls and Moll (1998) calculate that costs of this option
are high under European energy price conditions. In the case of lower natural
gas prices this option may be more attractive.
|Table 3.20: Specific carbon-emission
factors for fossil fuel use in manufacturing industry
The figures are calculated on the basis of the IEA Energy Balances
Specific carbon emission
Lowest specific carbon emission found
|Iron and steel industry
|Non-ferrous metals industry
|Non-metallic minerals industry
|Transportation equipment industry
|Food products industry
|Pulp and paper industry
126.96.36.199 Renewable Energy
See Section 188.8.131.52 for an extensive assessment of
renewable energy technology.
184.108.40.206 Carbon Dioxide Removal
Carbon dioxide recovery from flue gases is feasible from industrial processes
that are operated on a sufficiently large scale. Costs are comparable with the
costs of recovering CO2 from power plant flue gases. See the discussion
of these options in Section 220.127.116.11.
However, there are a number of sectors where cheaper recovery is possible.
These typically are processes where hydrogen is produced from fossil fuels,
leaving CO2 as a by-product. This is the case in ammonia production
(note that some of the CO2 is already utilized), and increasingly
in refineries. Costs can be limited to those of purification, drying and compression.
They can be on the order of about US$30/tC avoided (Farla et al., 1995). Another
example of carbon dioxide recovery connected to a specific process is the recovery
of CO2 from the calcination of sodium bicarbonate in soda ash production.
The company Botash in Botswana recovers and reuses 70% of the CO2
generated this way (Zhou and Landner, 1999). There are several industrial gas
streams with a high CO2 content from which carbon dioxide recovery
theoretically is more efficient than from flue gas (Radgen, 1999). However,
there are no technical solutions yet to realize this (Farla et al., 1995).
18.104.22.168 Material Efficiency Improvement
In heavy industry most of the energy is used to produce a limited number of
primary materials, like steel, cement, plastic, paper, etc. Apart from process
changes that directly reduce the CO2 emissions of the processes,
also the limitation of the use of these primary materials can help in reducing
CO2 emissions of these processes. A range of options is available:
material efficient product design (Brezet and van Hemel, 1997); material substitution;
product recycling; material recycling; quality cascading; and good housekeeping
(Worrell et al., 1995b). A review of such options is given in a report for the
An interesting integral approach to material efficiency improvement is the
suggestion of the inverse factory that does not transfer the ownership
of goods to the consumers, but just gives the right of use, taking back the
product after use for the purpose of reuse or recycling (Kashiwagi et al., 1999).
Some quantitative studies are available on the possible effects of material
efficiency improvement. For the USA, Ruth and Dell Anno (1997) calculate
that the effect of increased glass recycling on CO2 emissions is
limited. According to these authors, light-weighting of container glass products
may be more promising. In addition, Hekkert et al. (2000) show that product
recycling of glass bottles (instead of recycling the material to make new products)
is also a promising way to reduce CO2 emissions.
For packaging plastics it is estimated that more efficient design (e.g., use
of thinner sheets) and waste plastic recycling could lead to savings of about
30% on the related CO2 emissions. Hekkert et al. (2000) found
a technical potential for CO2 emission reduction for the total
packaging sector (including paper, wood, and metals) of about 50%.
Worrell et al. (1995c) estimate that more efficient use of fertilizer by, e.g.,
improved agricultural practices and slow release fertilizer, in the Netherlands
may lead to a reduction of fertilizer use by 40%.
Closed-loop cement recycling is not yet technically possible (UN, 1997). A
more important option for reducing both energy-related and process emissions
in the cement industry is the use of blended cements, where clinker as input
is replaced by, e.g., blast furnace slag or fly ash from coal combustion. Taking
into account the regional availability of such inputs and maximum replacement,
it is estimated that about 5%20% of total CO2 emissions of
the cement industry can be avoided. Costs of these alternative materials are
generally lower than those of clinker (IEA Greenhouse Gas R&D Programme,
1999). Note that these figures are based on a static analysis for the year 1990
(Worrell et al., 1995a).
Some integral approaches give an overview of the total possible impact of changes
in the material system. Gielen (1999) has modelled the total Western European
materials and energy system, using a linear optimization model (Markal). In
a baseline scenario emissions of greenhouse gases in the year 2030 are projected
to be 5000 MtCeq. At a cost of US$200/tC 10% of these emissions can
be avoided through material options; at a cost of US$800/tC this
increases to 20%. Apart from end-of-pipe options, especially material
substitution is important, e.g., replacement of petrochemical feedstocks by
biomass feedstocks (see also Chapter 4); steel by aluminium
in the transport sector; and concrete by wood in the buildings sector. At higher
costs, waste management options (energy recovery, plastics recycling) are also
selected by the model. Gielen (1999) notes that in his analysis the effect of
material efficiency of product design is underestimated.
A study for the UN (1997) estimates that the effect of material efficiency
improvement in an ecologically-driven/advanced technology
scenario in the year 2020 could make up a difference of 40 EJ in world primary
energy demand (approximately 7% of the baseline energy use), which is equivalent
to over 600 Mt of carbon emissions.