Analysis of energy consumption in the production of hot mix asphalt (batch mix plant)

2016 ◽  
Vol 43 (12) ◽  
pp. 1044-1051 ◽  
Author(s):  
Ivica Androjić ◽  
Zlata Dolaček Alduk

This paper describes tests in which influencing factors that affect energy consumption in the rotary drum were monitored. The monitored influencing factors are moisture, delays in daily production, hourly production capacity, and temperature of produced hot mix asphalt (HMA). The tests include the production of 88 079 t of HMA of continuous and discontinuous gradation on a cyclic asphalt plant in the Republic of Croatia. In 2014, 182 production terms were monitored (155 observed), whereas the moisture content was tested using the same number of input mineral mixture samples. The temperature of the produced asphalt mixture was measured using approximately 67 753 samples during the entire production period. Delays in work and hourly production capacity were measured during production by recording the duration of working time and delays. The final result of this study is the creation of a regression model of the correlation between energy consumption and temperature of the asphalt mixture and the hourly capacity and moisture in the mineral aggregate.

Author(s):  
Maicon Basso dos Santos ◽  
Jefferson Candido ◽  
Sofia De Souza Baulé ◽  
Yuri Mello Müller de Oliveira ◽  
Liseane Padilha Thives

Hot-mix asphalt used in pavement layers is produced by asphalt plants. In Brazil, despite the fact that these industrial units produce greenhouse gases, no control or measurement protocol has yet been established. This study aims to quantify emissions in different asphalt plants, in terms of carbon dioxide equivalent (CO2eq) and energy consumption. Asphalt plants were selected according to their type (batch or drum mix); production capacity (80 to 340 t/h), and whether mobile or fixed. In each plant, emissions were quantified and the energy consumption spent on drying and heating aggregates in the dryer drum was evaluated. The fuels used in the drier drum such as low pour point (LPP) oil, liquefied petroleum gas (LPG), and natural gas (NG) were evaluated and compared. The methodology consisted of surveying the thermal power of the dryer drum specified on the suppliers' catalog to calculate the volume of fuel required per ton of asphalt mixture produced. Based on the criterion of the lower calorific value of each fuel, the volume of fuel used was calculated according to the production of the asphalt plants. Through the GHC protocol tool, the quantification of emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) gases was obtained, and then transformed into CO2eq emissions. As a result, lower energy consumption was observed in the mobile batch plants and higher consumption in the mobile counterflow drum mix plants. On average, 27.69% less energy per ton of processed aggregate was needed compared to the mobile counterflow plants. The use of natural gas in the dryer drum and for all plant models was the least emissive fuel. The results showed that for the mobile batch type with a capacity of 140 t/h, the emission was 13.62 kg of CO2eq / t. On the other hand, with the mobile counterflow type with a capacity of 200 t/h, 13.64 kg of CO2eq/t was produced. Finally, with the fixed counterflow type with a production capacity of 240 t/h and 300 t/h, emissions of 13.67 kg of CO2eq/t were obtained. Through this study, the mobile batch plant with a capacity of 140 t/h using natural gas showed the least environmental impact. When natural gas was used, this model obtained energy consumption and emissions 54.5% lower than the mobile counterflow model with a capacity of 50 t/h which showed the worst environmental performance.


2021 ◽  
Vol 13 (10) ◽  
pp. 5703
Author(s):  
Jaehwan Seo ◽  
Bon Joo Koo

Though biological and ecological characteristics of Scopimera globosa have been intensively investigated, little has been understood on bioturbation, especially sediment reworking. This study was designed to evaluate variation on sediment reworking of S. globosa based on feeding pellet production (FP) and burrowing pellet production (BP) with influencing factors and estimating the chlorophyll content reduction within the surface sediment by its feeding. The FP and BP largely fluctuated according to chlorophyll a concentration and crab density, but both were not influenced by temperature. The FP was enhanced by chlorophyll a concentration, whereas both FP and BP were restricted by crab density. The daily individual production was highest in spring, followed by fall and summer, with values of 25.61, 20.70 and 3.90 g ind.−1 d−1, respectively, while the total daily production was highest in fall, followed by summer and spring 2150, 1660 and 660 g m−2 d−1, respectively. The daily sediment reworking based on the FP and BP of Scopimera was highest in fall, followed by summer and spring, with values of 1.91, 1.70 and 0.77 mm d-1 and the annual sediment reworking rate of this species was calculated 40 cm year−1 based on its density in this study area. The chlorophyll a reduction ratio was estimated from 11 to 24% in one day by its feeding. These results imply that the sediment reworking of S. globosa is regulated by food abundance and its density, and Scopimera is an important bioturbator, greatly influencing biogeochemical changes in the intertidal sediments.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1010
Author(s):  
Aichun Jiang ◽  
Qian Zhong ◽  
Yan Wang ◽  
Yibin Ao ◽  
Chuan Chen

With rapid rural urbanization and new rural construction, the commercial energy consumption of rural residents shows a trend of rapid growth, and China’s rural areas are also faced with environmental challenges brought by the increase of commercial energy consumption. China’s commercial energy consumption behavior of rural residents has also undergone tremendous changes. However, scholars have neglected the research on rural residents’ commercial energy consumption intention from a micro perspective. Therefore, this study takes the 5 villages in Chengdu out of the 100 representative villages in the Sichuan province as examples. From the perspective of the head of a family of permanent rural residents, extended planned behavior theory, exploratory factor analysis, and structural equation modeling are used to explore the influencing factors of rural resident commercial energy consumption intention and their relationship. Findings show that subjective norm, perceived behavioral control (PBC), and habit significantly affect residents’ behavioral intention. Habits significantly influence subjective norms and PBC. Therefore, in the new rural construction, rural residents are the main body and participants of energy consumption. Local government departments should plan reasonably according to the needs and characteristics of residents, constantly improve commercial energy infrastructure, improve service level, and further strengthen farmers’ attitude and satisfaction toward commercial energy. Moreover, they should increase the publicity and education of commercial energy, advocate green housing, and promote energy saving consumption reduction, and sustainable development in new rural areas.


2021 ◽  
Vol 13 (6) ◽  
pp. 3005
Author(s):  
Jiangang Yang ◽  
Chen Sun ◽  
Wenjie Tao ◽  
Jie Gao ◽  
Bocheng Huang ◽  
...  

In this study, the compaction characteristics of recycled hot-mix asphalt (RHMA) were evaluated using the void content (VV), compaction energy index (CEI), slope of accumulated compaction energy (K), and lock point (LP). Then, the effects of the compaction parameters, including the gradation of the RHMA, reclaimed asphalt pavement (RAP) content, temperature of gyrations, and number of gyrations, on the compaction characteristics of RHMA were investigated. An orthogonal experiment was designed and the data collected were analyzed via range analysis; then, a regression model was generated relying on a quadratic polynomial. Furthermore, the regression model was used for the comparison and prediction of the mixture’s compactability during the material design. Finally, the compaction mechanism of RHMA was discussed from the perspective of the void content of RAP particles. The results showed that a finer aggregate gradation, a higher gyration temperature, a greater number of gyrations, and a higher RAP content were effective for increasing the compactability of RHMA. The range analysis results suggest that the gradation of RHMA has the greatest influence on compactability, followed by the RAP content. The RAP aggregate cannot diffuse to a new mixture completely, so the remained RAP particle reduces the void content of RHMA. Therefore, a higher RAP content up to 50% can help RHMA to achieve the designed void content with higher efficiency.


2021 ◽  
Vol 13 (8) ◽  
pp. 4194
Author(s):  
Yanhua Guo ◽  
Lianjun Tong ◽  
Lin Mei

Winning the battle against pollution and strengthening ecological protection in all respects are vital for promoting green development and building a moderately prosperous ecological civilization in China. Using the entropy weight method, this paper establishes and evaluates a comprehensive industrial pollution index that contains and synthesizes six major industrial pollutants (wastewater, COD, waste gas, SO2, NOx, and solid waste) in the 2006–2015 period. Subsequently, this paper studies the spatiotemporal characteristics and influencing factors of industrial pollution via the Moran index and spatial econometric analysis. The empirical results indicate that (1) the temporal evolution of the industrial pollution index is characterized by an overall trend of first decreasing and then increasing. (2) The industrial pollution index of each county has certain geographical disparities and significant spatially polarized characteristics in 2006, 2009, 2012, and 2015. (3) The Moran test shows that there is a relatively significant spatial autocorrelation of the industrial pollution index among counties and that the geographical distribution of the industrial pollution index tends to show clustering. (4) Spatial regression models that incorporate spatial factors better explain the influencing factors of industrial pollution. The economic development level, technological progress, and industrialization are negatively correlated with industrial pollution, while population density and industrial production capacity are positively correlated. (5) Consequently, as relevant policy recommendations, this paper proposes that environmental cooperation linkage mechanisms, environmental protection credit systems, and green technology innovation systems should be established in different geographical locations to achieve the goals of green county construction and sustainable development.


2021 ◽  
Vol 1047 ◽  
pp. 179-185
Author(s):  
Siti Zubaidah Mohd Asri ◽  
Faridah Hanim Khairuddin ◽  
Choy Peng Ng ◽  
Noor Aina Misnon ◽  
Nur Izzi Md Yusoff ◽  
...  

Pavement failures such as fatigue, rutting, cracking, bleeding, and stripping are typical pavement deterioration. Researchers have been experimenting with pavement modification to overcome these problems. This study determines the optimum binder content (OBC) for modifying an asphalt mixture with a partial replacement of coarse aggregate (5mm-14mm sieve size) with palm kernel shell (PKS). A 60/70 penetration grade bitumen was mixed with 10, 20 and 30% PKS at selected aggregate gradation following the Public Work Department of Malaysia (JKR/SPJ/2008-S4) specification. The preparation of 60 samples of unmodified and modified asphalt mixture employed the Marshall Method compacted with 75 blows. The OBC was determined based on five volumetric properties of asphalt mixture namely stability, flow, bulk density, void filled with asphalt, and void in total mix. The OBC and volumetric properties of the modified PKS asphalt mixture samples were compared with unmodified asphalt mixture samples in accordance to the specification. Results showed that the OBC sample with 30% aggregate replacement produced the highest OBC value of 5.53% relative to the control sample with 5.40% OBC. The trend for OBC with PKS replacement begins with 10% PKS with 5.30% OBC, 20% PKS with 5.32% OBC and 30% PKS. All volumetric properties of the PKS samples are within the specification limit. Thus, PKS has a promising potential as a coarse aggregate replacement in asphalt mixture.


2012 ◽  
Vol 20 (1) ◽  
pp. 35-40
Author(s):  
S. Štefunková

Characteristics of asphalt mixes with FT additiveThis article is focused on low-temperature asphalt mixture technologies using FT additive and RAP. The modern production and use of asphalt mixture technologies with reduced temperatures has many advantages. These advantages mainly help to save energy and the environment. Lower temperatures enable a reduction in energy consumption, a more acceptable working environment for workers, a reduction in negative environmental effects, such as greenhouse gas emissions, and an improvement in the workability of mixtures and a prolongation of their duration. This technology is currently becoming popular in many countries.


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