THE EFFECT OF FLY ASH UTILIZATION IN REINFORCEMENT CONCRETE: A REVIEW

Indonesia signed the Paris Agreement on facing climate change. Carbon dioxide is the main issue contributing to the greenhouse effect. Most power plant in Indonesia uses non-renewable energy to generate electricity. Increasing demand for electricity makes increasing coal consumption for steam power plants and directly contributes to greenhouse gasses from coal combustion and produces fly ash as a waste product. Otherwise, fly ash from Steam Power Plant is classified as pozzolanic materials being a part of substitution ordinary portland cement (OPC) on making reinforcement concrete. Many Researchers studied reinforcement concrete from fly ash composition and others development using renewable energy resources such as biomass. This paper presents a literature review on focus studying the properties of various types of fly ash and their effect on the performance of concrete, including corrosion resistance.

The Wars of the 1860s and the Atlantic (Americas and Europe)

During the 1860s, widespread warfare beset the Americas and Europe. Fighting resulted from challenges to existing political accommodations, and evolved into civil wars or interstate violence. Concurrently, economic and technological transformations through the 1860s aided long-distance communications, such as the coming of the telegraph and a much faster spread of steam power that helped to disseminate news and share experiences. All over the Atlantic, the triumph of national unification was the most visible result of the bloodbath, expanding state capacities and reinforcing the role of national symbols as common elements of a shared identity. Political and administrative centralization affected the exercise of local power in different ways, mainly in its capacity to recruit members of communities for war; appealing to national values and identities gradually became central in the demands for cooperation and sacrifice. After the end of combat, national authorities established regimes founded either on new constitutions or on amendments added to existing documents, the goal of which was reordering society according to rules capable of regulating and institutionalizing regional conflicts, simultaneously incorporating demands for representation and liberalization. These same groups demonstrated less efficiency when dealing with ethnic and social conflicts, sources of deeper divisions in societies that pretended to be consistent, progressive, and unified.

Air Pollution Dispersion Modelling using GRAL in Area Near Coal-Steam Power Plant at Central Java

Sulfur dioxide and Nitrogen dioxide were significant emissions emitted from coal-steam power plants that may cause health problems for humans and damage the environment. Studying the SO2 and NO2 gradients in Indonesian residential communities is critical for evaluating resident's SO2 and NO2 exposure. The method developed to assist analysis of spatial SO2 and NO2 gradients on a community scale combines a mesoscale Lagrangian dispersion model with field observations around coal-steam power plants using GRAL. The objectives of this study focused on GRAL dispersion of SO2 and NO2 in an Indonesian residential community near the coal-steam power plant, with a 6 km x 8 km resolution. Analysis of this model indicates a correlation between simulation and observation, with SO2 coefficient correlation (R) within 0.5 – 0.82 and NO2 coefficient correlation (R) within 0.30 – 0.59. Model performances analyze by NMSE and FB. The SO2 model is comparable to observation data since it has a better average NMSE and FB than the NO2 model. Due to data limitation of observation collected by grab sampling instead of continuous ambient measurement system affect different respond time compared with hourly data from the model.

Social and Environmental Responsibility of Tidore ESPP to the Community of Tidore City Village, Tidore Islands

This study aims to (1) determine the implementation of social and environmental responsibility of ESPP Tidore to the community in the rum village (2) to determine the factors that influence the implementation of social and environmental responsibility of ESPP Tidore to the community of Rum City of Tidore Islands. The results showed that the Tidore ESPP was operated in mid 2017. After that, it was inaugurated by the Government in August 2016, until entering 2021 only 4 programs were implemented. Even though it has been in operation for 5 years. This indicates unpreparedness in the planning of Corporate Social Responsibility (CSR) programs and obstacles regarding the Technical component of Electric Steam Power Plant (ESPP) Operation. Distribution of Corporate Social Responsibility (CSR) and even then because it considers the pressure from the community for the sake of improving communication in the business climate, in addition to obligations that are regulated based on existing regulations.

Optimization of Integrated Gasification Combined-Cycle Power Plant for Polygeneration of Power and Chemicals

Efficient and flexible operation is essential for competitiveness in the energy market. However, the CO2 emissions of conventional power plants have become an increasingly significant environmental dilemma. In this study, the optimization of a steam power process of an IGCC was carried out, which improved the overall performance of the plant. CCPP with a subcritical HRSG was modelled using EBSILON Professional. The numerical results of the model were validated by measurements for three different load cases (100, 80, and 60%). The results are in agreement with the measured data, with deviations of less than 5% for each case. Based on the model validation, the model was modified for the use of syngas as feed and the integration of heat into an IGCC process. The integration was optimized with respect to the performance of the CCPP by varying the extraction points, adjusting the steam parameters of the extractions and modifying the steam cycle. For the 100% load case, a steam turbine power achieved increase of +34.2%. Finally, the optimized model was subjected to a sensitivity analysis to investigate the effects of varying the extraction mass flows on the output.

Performance and boiler efficiency using low-grade coal on 400 MWe coal-fired power plant: case study of Suralaya Power Plant Unit 2

In a coal steam power plant, changes in coal quality significantly affect plant performance, especially in its boiler. A coal-fired power plant with a capacity of 400 MWe had been commissioned using coal with a calorific value of 5,242 kCal/kg. This study aims to determine the effect on unit performance and boiler efficiency due to changes in fuel use with the typical calorific value of 3,520 kCal/kg, 34,17% lower than the initial design. The performance tests were conducted using the heat loss method at loads: 50%, 65%, 75%, and 100%. The test result showed that using low-grade coal reduces boiler efficiency by 6.26%. There were four dominant boiler losses: heat loss due to moisture in dry flue gas, heat loss due to combustible in refuse, heat loss due to moisture in fuel, and heat loss due to hydrogen burning. Furthermore, the gross plant heat rate using low-grade coal was increased from 2,120 kCal/kWh to 2,718 kCal/kWh; however, the electric price becomes cheaper from 1.99 cent-USD/kWh becomes 1.31 cent-USD/kWh.