International Best Practices for Pre-Processing and Co-Processing Municipal Solid Waste and Sewage Sludge in the Cement Industry

Abstract

Co-processing municipal solid waste (MSW) and sewage sludge in cement kilns can both reduce the cement industry's growing fossil fuel use and carbon dioxide (CO 2 ) emissions and help address the increasing need for safe and environmentally sensitive municipal waste treatment and disposal.The cement industry accounts for approximately 5 percent of current anthropogenic CO 2 emissions worldwide. Given increasing cement demand and production, the industry's absolute energy use and CO 2 emissions will continue to grow. Cement kilns typically burn fossil fuels, which are nonrenewable and being depleted rapidly. Treating wastes in cement kilns, known as co-processing, can reduce the industry's reliance on fossil fuels and decrease associated CO 2 emissions. The ashes from waste co-processing will be integrated into the clinker which can result in saving the virgin raw materials. In addition, treating wastes in cement production can help alleviate the problems associated with the increase in waste generation around the world, especially in developing countries experiencing rapid urbanization. Municipalities and governments in many urban areas, especially those with underdeveloped waste management systems, face growing difficulties disposing of MSW and sewage sludge in a manner that protects human and environmental health.The high temperatures and sufficiently long residence time in cement kilns and other characteristics of cement production make co-processing of waste materials a viable strategy. Wastes have been co-processed in cement kilns for more than 20 years, and this practice is prevalent in some developed countries such as the United States and Japan, as well as in a number of countries in the European Union. Many developing countries such as China and nations in Southeast Asia are initiating programs to promote co-processing of wastes in the cement industry. Regulations, standards, and the technical infrastructure in these developing countries are less mature than in countries that have a long experience with co-processing waste in the cement industry.

Guidelines and regulations for fecal sludge management from on-site sanitation facilities

“…However, it is possible to draw on existing regulations that have been developed for co-processing MSW and sewage sludge in the cement industry. Regulations and standards are needed in five key areas (Hasanbeigi et al 2012): (1) environmental performance, (2) product quality, (3) waste quality, (4) operational practices and (5) safety and health requirements for employees and local residents. As such, guiding points are (Hasanbeigi et al 2012) listed below:…”

Quantifying CO2 emissions from China’s cement industry

“…In 2011, the percentage of clinker in cement has been reduced to 62.8%, the cement with less clinker has lower cost so the cement industries have high initiative to use the solid waste or natural mineral admixture to produce blend cement. This strategy is another mean to comprehensively utilize the solid waste [12,45],. The high performance concrete will have more opportunity to mineral admixture utilization and reduce the CO 2 emission of concrete life cycle; (5) Less carbon emission cement clinker, clinker gives a prevail carbon emission of the Portland cements, the RM CO 2 is the main fraction, the most effective approach to cut carbon emissions is to substitute calcium carbonate raw materials with other calcium raw materials e.g.…”

Environmental potential analysis of co-processing waste in cement kilns

“…The key barriers the countries face on their way to implementing co-processing are comparable to the barriers also faced in China [17], plus the issue of increasing waste geneeration. China is now actively seeking to increase its waste recovery in cement kilns with producers such as Huaxin Wuxue and Sinoma's Liyang having taken up the challenge.…”