WASTE HEAT RECOVERY (WHR)

According to the 2016 General Energy Balance Table data of the T.R. Ministry of Energy and Natural Resources, energy consumption in all sectors is 104.332 Thousand TEP in total and 33.264 Thousand TEP energy is consumted by the industry sector. According to the sectorial benchmarking study conducted by the General Directorate of Renewable Energy, the cement sector accounts for 6,16% of total energy consumption and 19,32% of the industrial consumption in 2016 with its consumption of 6.426 thousand TEP.

Minimizing the cost of energy required to produce one unit of product is one of the most important factors for the sustainability of the energy intensive industrial enterprises. In the cement industry, which is the country's second largest energy consumer in the industrial sector, 70% of the costs on average are due to total energy consumption. Therefore, as an energy intensive sector, the cement industry adopts energy efficiency as a principle in terms of sustainability and reduction of energy consumption at the national level and environmental policies .

Adopting efficiency in energy consumption as a principle, our sector is increasing its investments for the waste heat recovery plants, where the heat, which is exhausted through kiln gas exit both from pre-heating and clinker cooling at the new generation rotary kiln systems made up of staged pre-heater towers at the kiln entrance and of cooling unit at the kiln exit can be converted into electricity at the feasible plants.

Within this scope, sector's roof organization Turkish Cement Manufacturers Association prepares various publications to increase the awareness of its members and to ensure that investment alternatives in technical and economic terms are introduced, holds seminars with its stakeholders for information purposes, thus demonstrates its supportive attitude to encourage investments for waste heat recovery plants, which are considered as an efficiency implementation.

Thanks to WHR facilities that can meet approximately 25% of the total electricity demand of a cement plant, the consumption of purchased electricity is reduced, contribution to supply security is ensured and since fossil fuels are not used in energy production both resources are protected and greenhouse gas emissions are reduced. In addition, due to the fact that high risk of increase in energy prices is controllable and it is possible to make on-site production and on-site consumption, energy losses are minimized and line investment requirements are reduced and these are some other advantages of waste heat recovery plant investments.

Total power of the commissioned waste heat recovery plant investments, whose feasibility is generally dependent on subtitles such as raw material moisture, electricity price, cement consumption, national policy and strategies and energy supply security, is 119,7 MW with 21 lines in 12 factories as of September 2018. This figure corresponds to daily electricity consumption of approximately 480.000 households.

Investments for 4 factories that will allow generation of 26,2 MW electricity on 4 lines in total are planned to be commissioned in the next couple of years. Feasibility studies for 25,5 MW production on 6 lines are ongoing at 5 factories.

It is estimated that 44 %of the total 270 MW capacity projected in 2007, when the first investments for electricity production from waste heat started, is achieved by these figures with the investments commissioned.

If resting 150 MW is also commissioned, 1,1 million MWh energy will be generated annually without the need for a new plant. Thanks to this, energy corresponding to daily electricity consumption of 1,1 million households will be saved. In addition to this, a reduction of approximately 590 tons in CO2 emissions will be achieved annually.      

Therefore, it should be noted that the hot gas energy to be put into the atmosphere due to the process is a significant potential capacity in reducing the need for the construction of new plants in response to the increasing energy demand in our country.
 
For these reasons, it is thought that arrangements to lead the way for encouraging plant investments that generate electricity by means of waste heat recovery will be an important source of motivation for all sectors with thermal process to take the aforementioned efficiency practices among their priority investment goals.