The Effect of Excess Heat Utilization on the Production Cost of Cement

Industrial excess heat is a largely untapped resource that has the potential for external use that would be beneficial to the cement industry. Therefore, this work studied the excess heat utilization for the optimization of production cost in a cement plant within a period of three years. The study of plant layout in the selected plant in Nigeria (Ewekoro II Cement Plant of 200 tonnes/hour) was carried out to identify areas where excess heat is generated. The temperature and static pressure of precalciner, kiln, and cyclone were taken using a temperature probe, pitot tube, digital manometer, and light-emitting diode temperature reader. These parameters were used to obtain the mass flow rate and heat transfer needed for the heat energy analysis of the system. The kiln was maintained at constant tonnage per hour through a clinker truck weighed using the weighbridge. The result showed that the heat generated from the kiln was 577,640,260 MJ/hr. through excess air draft of 780,000 m3/hr (89.4%) at 250 °C and induced draft fan of 900,000 m3/hr at 350 °C. The result showed that excess heat can be utilized in pre-heater and air quenched cooler boilers, steam turbines and auxiliaries, and generators. The total estimated heat that could be saved amounted to 344,648,250 MJ with a total annual capacity of 2.25 million tonnes of cement. A saving of over two billion dollars could be achieved in production cost per year.

A Report on Metal Forming Technology Transfer from Expert to Industry for Improving Production Efficiency

This article reports on technological mastery assistance in three small metal forming industries in Indonesia. Problems in the blangking and piercing separately process caused increased production time which resulted in inefficiency cost. Therefore, the expert team aided in metal forming technology through participatory action research (PAR) methods and experimental methods through reverse engineering for several products. The PAR method involves optimal contribution and participation from the industry. Assistance in mastering technology in small metal-forming industries reduces the manufacturing process from seven to three stages, increasing efficiency. The press machine's tonnage capacity must balance with the force blanking/piercing requirement. The minimum press machine requirement is 6.7 tons, and based on the availability of existing press machines, the expert team recommends a 20-ton capacity press machine. Total efficiency can be further increased by implementing full progressive die technology by combining piercing, blanking, and bending processes.

The Role of Composites for Sustainable Society and Industry

In the last few decades, the global community's demands are getting stronger for more environmentally friendly materials. Natural fiber reinforced composites have been applied as reinforcement in concrete, sound absorbers, buildings, aeronautical, aerospace, sanitation, electronics, bridge decks, interior, automotive, sports equipment and furniture industries, modular structures, and others. Natural fibers are receiving high attention due to their sustainability, environmental friendliness, low density, low cost, low abrasiveness, renewability, and biodegradability, as well as contributing to the consumption of CO2 gas. As reported by many researchers, Indonesia has several natural resources for natural fibers such as bark fiber, leaf fiber, seed/fruit fiber, grass fiber, stalk fiber, and wood fiber.

Emphasis of Weld Time, Shielding Gas and Oxygen Content in Activated Fluxes on the Weldment Microstructure

The activated-TIG (A-TIG) process is a recognised process for achieving higher depth-of- penetration (DoP) and it could be used for various stainless-steel grades welding. The oxygen content of oxide based activated fluxes provide the extra heat during decomposition of flux and result into deep penetration. This study reveals the effect of short weld time of 2 sec in stationary arc, shielding environment (Ar and Ar + 2.5 % H2) and an effect of oxygen element in activated flux (CrO3 and SiO2) on the microstructure and weld metal micro-hardness. Use of hydrogen mix shielding gas during A-TIG process has significant impact on the dilution rate, grain size and dendrite arm spacing. The fraction of oxygen in the flux and the presence of silicon in SiO2 flux play a significant role in achieving higher DoP. To evaluate the impact of different shielding environment on grain growth, the samples were investigated with weld pool morphology, depth of penetration, weld chemistry, optical microscopy and SEM analysis. The extra heat produced due to oxygen fraction in activated flux and H2 induced shielding have been quantified in the study. The ferrite and austenite grain growth as well as the dendrite arm spacing found to be increased due to presence of H2 in shielding gas.

Recent Progress on the Production of Aluminum Oxide (Al2O3) Nanoparticles: A Review

This study aims at discussing several methods to produce aluminum oxide (Al2O3) synthesis methods along with the advantages and disadvantages of each method used. In general, several methods are available: (1) precipitation, (2) combustion, (3) sol-gel, (4) wet chemical, (5) synthesis in supercritical water conditions, (6) microwave, (7) mechanochemical, and (8) hydrolysis, and the most efficient method for synthesizing Al2O3 is precipitation because it is facile and the simplest method (compared to other methods), can be proceeded using inexpensive raw materials, produces less pollution, and has several advantages: high purity product, high thermal stability, nearly homogeneous nanoparticle in size, and control desired particle size. The results of the study help to provide comparisons in producing various Al2O3 synthesis methods.

Data on Emission Factors of Gaseous Emissions from Combustion of Woody Biomasses as Potential Fuels for Firing Thermal Power Plants in Nigeria

This work generated data on the emission factors of air emissions from combustion of woody biomasses collected from southwest, Nigeria. This was with a view to finding their potentials as sustainable and environmentally friendly fuels for firing thermal power plants compared to coals. The data on heating values and elemental contents (carbon, sulphur and nitrogen) responsible for gaseous emissions in the 100 woody biomasses were collected from the previous results of this work to determine the gaseous emission factors on the expected condition of complete combustion. The current results showed that the CO2 emission factors ranged from 0.0147 kg/(MJ/kg) for Ficus mucuso to 0.1499 kg/(MJ/kg) for Spondias mombin, SO2 emission factors ranged from 0.0000000 kg/(MJ/kg) for Pterygota macrocarpa, Irvingia grandifolia, and fifteen others, to 0.0011341kg/(MJ/kg) for Khaya ivorensis, while NO2 emission factors ranged from 0.0000000 kg/(MJ/kg) for Citrus medica to 0.0035824 kg/(MJ/kg) for Ficus carica. Considering the minimal emissions from biomasses compared to coal species, serious political will is needed on the part of the Nigerian government to propagate these biomasses for fuels in firing the thermal plants in the country.

Tensile Strength and Density Evaluation of Composites from Waste Cotton Fabrics and High-Density Polyethylene (HDPE): Contributions to the Composite Industry and a Cleaner Environment

The growth of the textile industry and the massive use of plastic-based materials create economic growth, but it produces waste from post-use, such as clothing waste from cotton fabrics and HDPE that can be recycled and combined as composite materials. Therefore, an experiment was carried out to investigate and analyze the effect of the fiber volume fraction of waste cotton fabric (1.5%, 3.5%, 4.5%, 6%, and 7.5%) with straight fiber arrangement on the tensile strength and density. From the test results, a tensile strength of 178.4 MPa and 182.6 MPa was obtained for yield and max stress, respectively at a fiber volume fraction of 7.5%. Meanwhile, the highest density of 0.95 g/cm3 was obtained at 1.5% fiber volume fraction. The fracture macroscopic view of the specimen shows a resilience fracture (uneven and appears stringy). Although the strength of this composite cannot yet compete with the new composite material, it has a decent environmental contribution. Considering the availability of waste cotton fabrics and HDPE, it promises to be produced as a low-strength composite for construction, ornamentation, or coatings.

Biodiesel Production from Waste Cooking Oil: Characterization, Modeling and Optimization

In this study, waste and discarded cooking oils (WCO) of palm, sunflower, rice bran and groundnut oils are collected from local restaurants. The high viscous WCO was converted into waste cooking oil biodiesel (WCOBD) by a single-stage transesterification process. During the transesterification process, the important parameters which show a significant change in biodiesel yield are studied using the optimization tool of response surface methodology (RSM). Results reported that 91.30% biodiesel yield was achieved within L18 experiments and NaOH catalyst was identified as the most influential parameter on WCOBD yield. Artificial Intelligence (AI) based modeling was also carried out to predict biodiesel yield. From AI modeling, a predicted yield of 92.88% was achieved, which is 1.70% higher than the RSM method. These results reveal the prediction capabilities and accuracy of the chosen modeling and optimization methods. In addition, the significant fuel properties are measured and observed within the scope of ASTM standards (ASTMD6751) and fatty acid profiles from chromatography reveal the presence of high unsaturated fatty acids in WCOBD. Therefore, utilizing the waste cooking oils for biodiesel production can mitigate the global challenges of environmental and energy paucity.

Mechanical Engineering for Society and Industry: A Preface

In a research cycle, researchers need to publish their work and readers expect reliable arguments and information. Seeing society and industry needs relate to mechanical engineering for now and in the future, Mechanical Engineering for Society and Industry (MESI) is an important journal to discuss problems and solutions in mechanical engineering practice. The articles in this journal are a representation of scientific editors and advisory boards' dedication, reviewers' contributions in improving articles quality, and authors contributions in providing standardized articles. Hopefully, this journal can be a source of new insights and inspiration for further research, as well as a new reference for society and industry to solve their problems.

Industry 4.0: Challenges of Mechanical Engineering for Society and Industry

Today, in the industry 4.0 era, the boundaries of scientific disciplines are blurred, everything seems to be interrelated and shows the ability to be combined. Intelligent sensors combined with Artificial Intelligence (AI) have demonstrated their ability to influence processes, design, and maintenance in manufacturing systems. Mechanical engineering tasked with solving complex engineering problems must be able to adapt to this transformation, especially in the use of digital and IT to combine the principles of physics and engineering mathematics with materials science to design, analyze, manufacture, and maintain mechanical systems. On the other hand, mechanical engineering must also contribute to a better future life. Therefore, one of the keys to consistently playing a role is to think about sustainability, in order to provide benefits for society and industry, in any industrial era.