7.3.5 Renewable energy

The use of biomass is well established in some industries. The pulp and paper industry uses biomass for much of its energy needs (See Section 7.4.6.). In many developing countries the sugar industry uses bagasse and the edible oils industry uses byproduct wastes to generate steam and/or electricity (See Section 7.4.7.). The use of bagasse for energy is likely to grow as more becomes available as a byproduct of sugar-based ethanol production (Kaltner et al., 2005). When economically attractive, other industries use biomass fuels, for example charcoal in blast furnaces in Brazil (Kim and Worrell, 2002a). These applications will reduce CO₂ emissions, but will only achieve zero net CO₂ emissions if the biomass is grown sustainably.

Industry also can use solar or wind generated electricity, if it is available. The potential for this technology is discussed in Section 4.3.3. The food and jute industries make use of solar energy for drying in appropriate climates (Das and Roy, 1994). The African Rural Energy Enterprise Development initiative is promoting the use of solar food driers in Mali and Tanzania to preserve fresh produce for local use and for the commercial market (AREED, 2000). Concentrating solar power could be used to provide process heat for industrial purposes, though there are currently no commercial applications (IEA-SolarPACES, n.d.).

7.3.6 Materials efficiency and recycling

Materials efficiency refers to the reduction of energy use by the appropriate choice of materials and recycling. Many of these options are applicable to the transport and building sectors and are discussed in Chapter 5, section 5.3.1 and Chapter 6, section 6.4. Recycling is the best-documented material efficiency option for the industrial sector. Recycling of steel in electric arc furnaces accounts about a third of world production and typically uses 60–70% less energy (De Beer et al., 1998). This technology, and options for further energy savings, are discussed in Section 7.4.1. Recycling aluminium requires only 5% of the energy of primary aluminium production. Recycled aluminium from used products and sources outside the aluminium industry now constitutes 33% of world supply and is forecast to rise to 40% by 2025 (IAI, 2006b, Martcheck, 2006). Recycling is also an important energy saving factor in other non-ferrous metal industries, as well as the glass and plastics industries (GOI, various issues). Recycling occurs both internally within plants and externally in the waste management sector (See Section 10.4.5).

Materials substitution, for example the addition of wastes (blast furnace slag, fly ash) and geo-polymers to clinker to reduce CO₂ emissions from cement manufacture (See Section 7.4.5.1), is also applicable to the industrial sector. Some materials substitution options, for example the production of lightweight materials for vehicles, can increase GHG emissions from the industrial sector, which will be more than offset by the reduction of emissions from other sectors (See Section 7.4.9). Use of bio-materials is a special case of materials substitution. No projections of the GHG mitigation potential of this option were found in the literature.