## 2 Literature Review  
The performance requirements for road-building machinery, including asphalt-mixing machines (AMMs), are continuously increasing. Road quality depends on the operation of the metering, batching and combustion systems of the AMMs [1]. According to standard [2], while considering the principle of the production of the asphalt mixture, AMPs fall into the  
Figure 1: The research framework diagram of the study. following categories: batch, continuous and drum mix plants. The most common are the drum mix and batch plants [3]. In most countries, the volumes of asphalt mixture produced for road pavements tend to increase. Currently, the majority of roads in the United States (US) have asphalt surfaces. The exact number of HMA plants in the US is unknown; according to the literature [4], there are about 3600. In [5], the authors state that the number of the hot mix asphalt (HMA) plants is equal to 4500; in Europe, there are about 4000 HMA plants. According to the National Asphalt Pavement Association of the US, the investment in the transportation infrastructure accounts for 7% of the Gross Domestic Product. These investments increase every year because of pavement durability, safety and efficiency, requiring modified materials due to the increased number of vehicles and their loads [6]. Asphalt production is a highly energy-consuming process [7]. Asphalt concrete includes mineral components and a bituminous binder that makes the hydrocarbon material. Before mixing the aggregates, they need to be dried and heated. These procedures are performed in the rotary drum and have never been studied from a physical perspective [8]. Bitumen-aggregate mixtures for pavements have been produced for many years using conventional batch mixing equipment [9]. [PERSON], in [10], used a combination of the computational fluid dynamics and the discrete element method to simulate the thermodynamic processes occurring in the drum dryer of an AMP. Therefore, the minimisation of the energy consumption for manufacturing HMA and the stricter requirements for the asphalt plant emissions have become essential issues [11]. [PERSON] et al. [12] combined a study on the process of energy usage in two AMPs. It was found that a large part of the energy was used for drying and heating the aggregate. The statistical analysis of the historical data was provided; the analysis of the data on the energy consumption showed a high correlation between specific energy consumption and the rainfall level. [PERSON] et al. [13] suggested that a possible way to achieve energy efficiency and, therefore, sustainability is to preheat the mineral mixture before it enters the production process in the asphalt mixing plant, thus resulting in lower energy consumption per ton of asphalt. [PERSON] et al. [14] identified factors that affect the energy consumption during the HMA production by focusing on the amount of fuel needed for drying and heating the aggregate while considering their moisture as well. It was found that energy consumption can be reduced by approximately 15% by decreasing the moisture content only by around 1%. In [8], the authors analysed the drying and heating processes when the aggregate and hot gases were involved in the co-current flow. This step of the process requires a large amount of the overall energy needed for HMA manufacturing. The analysis of the energy and exergy in a rotary dryer employed in a HMA plant for heating and drying the aggregate in the mixture is presented in [4]. Many emissions are released into the environment during the production of road pavement materials [15]. In [7], the authors presented the idea of the open life cycle assessment framework, which allows the quantification of the potential environmental impacts due to the construction, maintenance and disposal of roads. It was found that the asphalt production stage and the transporting process were the two most energy-consuming and most polluting stages. [PERSON] et al.