Utilization of refuse derived fuel in cement industry - a case study in China
Wang, Cong (2017)
Diplomityö
2017
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2017121355795
https://urn.fi/URN:NBN:fi-fe2017121355795
Tiivistelmä
Cement industry is energy intensive. Global cement production, requiring significant amounts of energy and materials, is responsible for 5% of global CO2 emissions. On the other hand, municipal solid waste (MSW) generation is greatly increasing globally and causing environmental burden. Using RDF as an alternative fuel in cement kilns saves fossil fuels such as coal and petroleum coke and reduces GHG emissions. The fly ash and bottom ash from incineration of RDF can be used as alternative raw materials for cement production.
China has some policies to promote and regulate co-processing of MSW in cement kilns. “Notice on carrying out the pilot work of co-processing of MSW in cement kilns” (Joint section of Industry and Information Office No. 28, 2015) aims to develop available technologies through study on six pilot projects in China before co-processing of MSW in cement kilns is promoted in the whole country. Later Guizhou province was selected as the pilot province for co-processing of MSW in cement kilns and eight projects in Guizhou were chosen to be pilot projects. In “Technical policy for pollution control on co-processing of solid waste in cement kilns” (Ministry of Environmental Protection, Notice No. 72, 2016), co-processing of MSW is seen as an important supplementary technology for incineration and landfill.
In China, Conch, Jinyu and Huaxin are primary leading companies in co-processing of MSW in cement kilns. Conch’s technology treats shredded MSW in gasification furnace and transports flammable gases from the furnace to the cement kiln for further incineration. Huaxin produces RDF in pretreatment plants and uses RDF in cement kilns. Jinyu uses RDF for direct incineration in cement kilns or gasifies RDF and uses gases in cement kilns according to its heating value.
A case study is done in a Huaxin’s cement plant which has a RDF plant. The example plant uses 45 000 tonnes of RDF and 50 000 tonnes of coal per year. 46 144 tonnes of CO2eq emissions are reduced per year in the example plant. If all cement plants in China use RDF and the share of heat provided by RDF is similar to that in the example plant, 307 million tonnes of MSW per year would be directed from landfills to RDF production and 138 million tonnes of RDF would be used in cement kilns. Annual reduction of GHG emissions would be 142 million tonnes CO2eq.
China has some policies to promote and regulate co-processing of MSW in cement kilns. “Notice on carrying out the pilot work of co-processing of MSW in cement kilns” (Joint section of Industry and Information Office No. 28, 2015) aims to develop available technologies through study on six pilot projects in China before co-processing of MSW in cement kilns is promoted in the whole country. Later Guizhou province was selected as the pilot province for co-processing of MSW in cement kilns and eight projects in Guizhou were chosen to be pilot projects. In “Technical policy for pollution control on co-processing of solid waste in cement kilns” (Ministry of Environmental Protection, Notice No. 72, 2016), co-processing of MSW is seen as an important supplementary technology for incineration and landfill.
In China, Conch, Jinyu and Huaxin are primary leading companies in co-processing of MSW in cement kilns. Conch’s technology treats shredded MSW in gasification furnace and transports flammable gases from the furnace to the cement kiln for further incineration. Huaxin produces RDF in pretreatment plants and uses RDF in cement kilns. Jinyu uses RDF for direct incineration in cement kilns or gasifies RDF and uses gases in cement kilns according to its heating value.
A case study is done in a Huaxin’s cement plant which has a RDF plant. The example plant uses 45 000 tonnes of RDF and 50 000 tonnes of coal per year. 46 144 tonnes of CO2eq emissions are reduced per year in the example plant. If all cement plants in China use RDF and the share of heat provided by RDF is similar to that in the example plant, 307 million tonnes of MSW per year would be directed from landfills to RDF production and 138 million tonnes of RDF would be used in cement kilns. Annual reduction of GHG emissions would be 142 million tonnes CO2eq.