Ultra-super critical technology (USC) allows the generator to produce electricity more efficiently, applied in such a way as to remain environmentally friendly.Indonesia's commitment to play a role in tackling climate change is no joke.This commitment is strengthened by the formulation of a number of policies, particularly in the energy sector, from upstream to downstream.All of these steps were taken in order to achieve the emission reduction target and net zero emission (carbon neutrality) by 2060. To carry out this mission, the carrying capacity of the energy transition is needed, so that the space for optimal utilization of new and renewable energy can be more widely opened.Along with that, of course, a number of efforts have also been made to reduce the use of fossil energy sources, or at least minimize their impact on the environment.For example, what is done by the largest electricity supplier in Indonesia, which supplies up to 18% of Java and Bali's electricity needs of 26,000 megawatts, the Suralaya Steam Power Plant (PLTU) in Cilegon, Banten.One of the strategic power plant projects has also carried out a number of efforts by applying environmentally friendly technology in the construction of one of its engineering, procurement and construction (EPC) projects.In collaboration with PT Hutama Karya and Doosan Heavy Industry, PLTU Suralaya has entrusted the construction of the PLTU project with a capacity of 2x 1,000 MW to the consortium.Hutama Karya is not a new player in the energy sector.Specifically for EPC, the company's portfolio includes the PLTU Kendari, Ampana, Harjosari, Labur, and PLTGU Grati projects in Pasuruan in 2019.In this project, as conveyed by the Director of Operations II Hutama Karya Ferry Febrianto, in a press release on Thursday (21/7/2022), the consortium will work on the development of the PLTU Suralaya project for the Java 9 and 10 power plants, which are coal fired. steam power plant with the latest and most efficient ultra-super critical (USC) technology.The project is worth IDR 26 trillion and will be completed in 2025, according to the initial contract with Indo Raya Tenaga or IRT as the project owner.As of July 2022, the project's progress has reached more than 42.92%.The current stage is working on areas of concern, such as turbine building, BOP, jetty, intake, CHS, and chimney (chimney).In addition, the buildings in the power block area have also been seen in their form, including two turbine buildings, each in the process of installing steel frames.Flanked by the two buildings, you can also see the central control building (CCB) which has entered the stage of mechanical and electrical architectural work.The project has also successfully completed the largest number of castings in the foundation area of ​​the chimney building of 6,000 m3.The use of USC technology itself is the choice of PLTU Suralaya because it allows the generator to produce electricity efficiently and cost-efficiently.Because of this technology, the amount of coal and fuel oil needed is less than other power systems.Of course, using less coal will also result in less pollution.It is known, contained in the existing regulations, the quality standards for the content of PLTU exhaust gases such as SOx, particulates, and NOx are respectively 550 mg/Nm3, 100 mg/Nm3 and 550 mg/Nm3.Through the USC technology, successively for SOx, particulates, and NOx can be reduced to below 350 mg/Nm3, 30 mg/Nm3, and 128mg/Nm3.USC technology is also known to have higher thermal efficiency than subcritical and supercritical technologies.Where the higher the thermal efficiency is produced, the less amount of coal is needed for the combustion process.“This means that to produce the same energy output, USC technology requires less coal than subcritical or supercritical technology.This also affects the level of pollution produced.Coal contains sulfur, which when burned will produce sulfur dioxide (SO2).If SO2 is released into the atmosphere, and mixed with clouds, it will produce acid rain.Because the amount of coal required is less, USC technology can produce less SO2 content, making it more environmentally friendly,” said Ferry.Not only applying advanced technology that is environmentally friendly, PLTU Suralaya's serious attention to this aspect is also shown by the use of a series of sophisticated systems in dealing with exhaust gas problems.A series of systems used are electrostatic precipitator system, flue gas desulphurization system, and selective catalytic converter.Through these systems in the future, the hazardous content of the exhaust gases, such as Nitrogen Oxide (NOx), Sulfur Oxide (SO2), and solid particulate matter, can be reduced to a safe level or even eliminated.Not only that, PLTU Suralaya also implements the latest technology to reduce pollution caused by burning coal.The boiler system in the project is known to use Low NOx Burner technology.The Low NOx Burner uses a system that can control the air and fuel mixture so as to produce a low Nitrogen Oxide (NOx) content.NOx is a gas that is dangerous when released into the atmosphere and inhaled by humans.After that, the gas from the coal combustion from the boiler is then channeled to the selective catalytic reduction (SCR) system.In this system, the exhaust gas will be injected with ammonia using an ammonia injection system.This process will produce a chemical reaction between ammonia and N0x, so that the exhaust gas is free from the content of N0x.Furthermore, the exhaust gas will be channeled to the Electrostatic Precipitator (ESP).The purpose of ESP is to filter out solid particulates resulting from coal combustion so that they are not released into the air.The ESP system then generates an electrostatic field that allows the particulates from the exhaust gas to be attracted to and attached to the anode in the ESP.Then the interested particulates are collected for further treatment.From the ESP, the particulate gas that has been filtered then enters the flue gas desulphurization system (FGD).This FGD serves to neutralize the SO2 content.The gas from the ESP will be channeled to the FGD, where the gas will be sprayed with limestone liquid to bind the SO2 content.“The clean exhaust gas is then discharged through the chimney.The exhaust gas content is continuously controlled using the continuous emission monitoring system installed in Chemne.In essence, the Suralaya PLTU will ensure that the exhaust gases from coal combustion always meet the applicable environmental standards," said Ferry.Author: Eri Sutrisno Editor: Ratna Nuraini/Elvira Inda Sari