Cement Kilns examples

Burning biomass in cement kilns is occurring more often due to volatile energy prices and environmental benefits. The following are a few examples reported in various publications.

Kenya: A cement firm operating in Kenya and Uganda claims to have cut its “annual carbon dioxide emission by reducing its use of fossil fuels in cement making by 20 percent. The company, which is partly owned by Lafarge Cement, plans to reduce its use of coal by using wood from its own plantations as well as coffee, rice and cashew nut husks. It is targeting a reduction of 132,000 tonnes of CO2 per annum by 2010.” (Reuters, March 11, 2008; Lafarge, 2007).

Uganda: Uganda’s Hima cement factory burns coffee husks as a CDM project. This project is expected to save the factory about $3.1 million in foreign exchange per annum (Cement World, 21 May, 2008).

Malaysia: Investigations performed to evaluate the feasibility of using biomass fuels as a substitute for fossil fuels in Malaysia’s cement industry have reached the following conclusions (Evald and Majidi, 2004):

• The economic feasibility of using biomass in the cement industry is very good, with a 263 percent financial internal rate of return (FIRR)
• The cement sector is an obvious choice for the use of solid biomass because of the ease of replacement of coal.
• For the cement industry, the combination of a very large volume of fuel substitution involving a relatively small investment cost allows for significant savings from the use of alternative fuels.

Germany: Heidelberg Cement claims to have increased the use of alternative fuels up to 78 percent in one of its plants and 66 percent in another. It uses tyres, plastics, paper residues, animal meal, grease and sewage sludge to replace fossil fuels. It states that the company had to invest EURO 8 million in one plant and another EURO 4 million on storage equipment, homogenization and dosing installations for flexible use of alternative fuels (Hridelberg Cement, 2009a).

Indonesia: Heidelberg Cement’s Indonesian subsidiary was approved as the first CDM project in Indonesia in 2005. The company claims to have increased the use of alternative fuels, in particular rice husks and residues from palm oil production, replacing coal (Hridelberg Cement, 2009b).

Poland: Six cement plants in Poland currently use alternative fuels. Lafarge Poland Ltd. has been using combustible fractions of municipal wastes, liquid crude-oil derived wastes, car tyres, waste products derived from paint and varnish production, expired medicines from the pharmaceutical industry, bone meal provided from meat processing plants, coke from the chemical industry and emulsified oil from a refinery (Mokrzychi et al, 2003).

India: Cement companies in India are using non-fossil fuels including agricultural wastes, sewage, domestic refuse and used tyres, as well as a wide range of waste solvents and other organic liquids (Bernstein and Roy, 2007). The Indian Cement firm ACC is using cow dung, old shampoo, soap, plant sludge and municipal waste as alternatives to fossil fuels (Cement World, 2008).

USA: In the United States, approximately 5 percent of fuel used in the cement industry comes from renewable and non-renewable waste fuels such as wood, tyres and other non-hazardous and hazardous materials. Various sources suggest the availability of millions of tonnes of wood that could be used in cement factories to reduce greenhouse gas emissions and minimise forest fires (Mackes and Lightburn, 2003).

UK: Cemex cement factory in Rugby uses alternative fuels such as tyres and ‘climafuel’, which is derived from household and commercial wastes. The ‘climafuel’ can contain at least 50 percent biomass, displacing nearly 180,000 tonnes of fossil fuel CO2 (Cemex, 2009; Cement News, January 2009). The Lafarge plant at Hope uses bone meal (MBM) which is expected to reduce 30,000 tonnes of CO2 emissions per year (Cement World, October 2008).

Austria: Austria’s cement factories were amongst the earliest to start burning tyres (since the 1980s), and have been burning solid waste such as plastics, paper, textile and composite materials since 1993. All nine cement plants in Austria use solid waste to various degrees (European Cement Association, 2009).

One of the factories, Wietersdorfer & Peggauer cement plant, claims to have used alternative fuels substituting up to 70 percent of fossil fuels (Zieri, 2007).

Tunisia: A feasibility study carried out to study the use of municipal solid waste (MSW) as a replacement for natural gas in the cement industry was found to be unattractive economically due to the high cost involved in collection and sorting of the MSW and government subsidies on natural gas imports (Lechtenberg, 2008).

Canada: St. Mary Cement in Ontario, Canada, wants to replace 13 percent of its fuel consumption with wastes such as paper sludge left over from recycling and plastic films. A factory in British Colombia uses renewable synthesis gas products from its gasifier, enabling it to replace 6 percent of its fossil fuel consumption (Dufton, 2001)

Portugual: Cement producer Cimpor Cimentos de Portugal is using hazardous hydrocarbon waste in its plant in Souselas, Central Portugal (Cement World, 2008).

The list of cement factories using biomass and waste fuels is longer, but the above diverse examples are sufficient to strengthen the argument that:

• Biomass and alternative fuels can be used in the cement industry.
• Biomass, as well as non-renewable waste fuels, can be an economical alternative to fossil fuels.
• There is well-established materials preparation, feeding and burning technology that can be purchased by cement factories to adopt a co-firing technology. It is clear that using biomass in the cement industry is possible and achievable. In the following section some of the benefits are discussed.