The cement industry is an energy- and material- intensive sector and the production of cement has a strong environmental impact as it contributes to greenhouse gases emission. The EU's climate policy assumes that the cement industry will reduce the level of its CO2 emissions by around 40% by 2030 with the target of reaching net-zero emissions by 2050. Therefore, improving energy and ecological efficiency constitute currently the industry priority objectives in terms of sustainable development to meet the targets set by the European Union. Considering the whole manufacturing process, the most energy consumption unit is the transformation of raw materials into clinker in the rotary kilns. Besides, a large amount of carbon dioxide is released at this stage as a result of the calcium carbonate decomposition reaction. The first step taken to achieve energy efficiency was the introduction of the dry method and the use of an external cyclone heat exchanger as well as a pre-decarbonization system in a rotary kiln. As a result, the modernization of cement plants enabled to reduce the specific heat consumption by almost 40%. The next effective way to lower production costs and carbon emissions from the clinker production process is the co-combustion of waste in cement kilns. The present study analyzed the environmental and financial benefits correlated with the partial substitution of fossil fuel by waste. The mass of alternative fuels needed to supplement the heat deficit due to fossil fuel limitation in cement kiln and benefit from avoiding carbon dioxide emission was calculated. Additionally, the economic benefits of partial replacement of coal by the alternative fuels were studied.