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.

Pengendalian Persediaan Batubara Menggunakan Metode Economic Order Quantity (EOQ) (Studi Kasus : PT. Indah Kiat Pulp & Paper tbk)

PT. Indah Kiat Pulp and Paper Perawang Mill is one of the largest pulp and paper producing companies in Indonesia and even in Southeast Asia. This company produces its own energy for production purposes. Where this company has 12 Steam Power Plants (PLTU) with a boiler system. This Steam Power Plant (PLTU) uses several types of fuel, both biomass and fossil fuel types. The main fuel used is the type of fossil coal. However, currently the coal inventory control process has not been carried out properly so that a lot of coal is piled up in the stockpile and causes coal to burn (Spontanous Comustion). In order not to cause losses to the company, the control of coal inventory must be carried out properly. One method that can be used is the Economic Order Quantity (EOQ) method for 12 periods (1 year) namely December 2020 – November 2021. From the results of this inventory control, the number of economic orders for coal is 20,841 tons with a total of 107 orders. To avoid stockpiling or shortages, a safety stock is needed, namely 847,439 Tons, while reordering can be done when the coal stock in the stockpile is 522,155 Tons remaining. With maximum stock in stockpile is 868,820 Tons. The total cost for coal inventory that must be spent is Rp. 23,244,747. Keywords : Coal, Inventory Control, Economic Order Quantity (EOQ)

PENGARUH VERMIKOMPOS ABU TERBANG BATUBARA MENGGUNAKAN CACING TANAH Eisenia fetida TERHADAP KANDUNGAN N, P, K, DAN Pb

The plan to build a coal-fired steam power plant is expected to increase. One of the wastes generated from coal-fired steam power plants is coal fly ash. The accumulation of coal fly ash can cause environmental pollution such as soil and groundwater pollution in the storage location. Vermicompost can be used for managing coal fly ash by utilizing earthworms as decomposers. Earthworms can increase the availability of nutrients such as nitrogen, phosphorus, and potassium and reduce the solubility of lead contained in coal fly ash. The purpose of this study was to determine the effect of vermicompost using earthworm Eisenia fetida on the content of nitrogen, phosphorus, potassium, and lead in coal fly ash. The study consisted of five treatments, with a total weight of 3 kg coal fly ash each. The results showed that mixing cow dung in vermicomposting of coal fly ash significantly increased N, P, K and decreased Pb in vermicompost.

Experimental Study of Concentrated Solar Power on Heat Feed Water Heaters in Steam Power Plants in Iraq

For generating power, solar energy is counted a good exporter. Iraq is located in a hot zonewith latitude from 32 degree N to 36 degree N. In Iraq, the average solar radiation is about 7kilowatt hours / day.In this work, central receiving tower was used to obtain steam using the available solar energyin summer and winter. To heat the feed water heater of South Baghdad Electrical Steam PowerPlant, steam utilization for this purpose. In the project, manufacturing the central receivertower, which is consisting of 150 mirrors fixed upon 75 manual tracking heliostats arranged forutilization the solar radiation concentrated on the central receiving tank (CRT). Pipes systemswere used for hot water or steam exits from receiver. In this study, the central receiver tank(0.5m*1m) was filled with 157 liter of water. The experimental work was run for one yearfrom June 2015 – May 2016. The outlet temperature of water from central tower receiver wassteam for (July and August 2015) and hot water with high temperature for other months of theyear. The results obtained from our system, solar shares for heating the feed water heater ofSouth Baghdad Electrical Steam Power Plant up to 1.86 % and an annual average of 1.03%.Temperature, power concentration factor and system efficient are greatly influenced by thenumber of heliostats used. A sample of calculations is used to evaluate the mathematical dataof hot water and steam temperatures obtained from this study. These values are approximatewith experimental data when compared together.