Air Quality Management
SCG is mindful of the significance in eradicating air pollution from stacks. SCG has used the best available technology and provided continuous air quality monitoring via Continuous Emission Monitoring Systems to ensure precautions against any risk.
SCG is committed to reduce all relevant air emissions using best in-class technology solutions to obtain fast, accurate and actionable data for analysis and prevention of potential impact. The process yields evidence for formulation of targets, as well as monitoring and disclosure of air quality related data to the public sector and the public.
Oxide of Nitrogen
Most oxide of nitrogen at SCG occurs in the cement manufacturing process from combustion inside the kiln which requires a temperature of up to 1,000 °C and the nitrogen molecules in the fuel which reacts to the oxygen during combustion.
SCG Cement business has joined the Global Cement and Concrete Association (GCCA) and is determined to control the oxide of nitrogen emission to below 1,700 grams per ton clinker. This requires highly efficient technology and Initiatives to reduce air emissions such as the installation of Low NOx Burner at every cement kiln to reduce oxide of nitrogen or adjusting the Preheater Cyclone and Calciner system to control the proper fuel and air ratio during combustion and reduce excess air to minimize nitrogen and oxygen reaction for higher combustion efficiency.
Maptaphut area in Rayong province also highlights oxide of nitrogen emission as power plants and chemical manufacturers with high-temperature combustion are located in the area. SCGC is mindful of the necessity to reduce emission, especially in the cracker furnace unit. SCGC has installed an Ultra-Low NOx burner that can reduce oxide of nitrogen emission 80% better than typical burners, thus, reducing energy consumption. SCGC requires that Ultra-Low NOx burners are used in all of its chemical plants as a minimum requirement which is stated clearly in the factory blueprint. Additionally, SCGP has installed a highly efficient boiler which can stabilize the combustion temperature. This also contributes to the decrease of the oxide of nitrogen emission.
Oxide of Sulfur
Oxide of sulfur is the main cause of acid rain. 90% of it is produced in the manufacturing process from fuel combustion, especially with coal which contains sulfur. The cement business has limited sulfur dioxide (SO2) emission from exhaust stacks with reference to the GCCA agreement at 120 grams per ton clinker. This is executed by installing a calciner to help decrease emission.
SCGP uses coal as the main source of energy to provide heat for the boilers. Therefore, SCGP initiated measures to reduce sulfur dioxide emission by controlling the whole process. This begins with selecting high-quality coal with low sulfur, increasing the portion of waste reject usage derived from waste paper, and using biogas from the anaerobic wastewater treatment to substitute coal. Moreover, polluted air is treated before release to the environment by adding limestone which becomes gypsum that can be reused in the cement manufacturing process.
Particulate Matter contributes greatly to the substances generated from the cement manufacturing process. It occurs in the raw materials grinding process, combustion and reactions, clinker grinding, packaging, and the transportation of the raw materials and cement.
SCG joined the GCCA as an attempt to control dust particles emitted from the stacks to be less than 150 grams per ton clinker. This involves installing efficient technology to limit the emission to be within the stated target. Measures include installing high-performance dust collector using electrostatic and filter bags that can increase performances to 99.9% as well as designing a closed-system building, machine, and conveying structure to prevent spreading outside of the working area.
Volatile Organic Compounds (VOCs)
The petrochemicals industry emits Volatile Organic Compounds or VOCs from the raw materials and the by-products. VOCs that affect the health of exposed individuals are Benzene, Toluene, Butadiene, and other substances that may pollute the earth’s ozone leading to respiratory infections.
SCGC explored and identified the source of VOCs in different units such as the raw materials storage tank, material and product transportation process, waste water management system, and by-product from combustion. Afterward, SCGC enhanced processes to minimize spreading and leakage of the VOCs. This includes closed-system plant design, upward product conveyors, enclosed waste water management system, checks and repairs of joints, valves, and other parts of the pipes, sealed sampling collecting unit, seamless pumps, and roofed naphtha tanks which provided over 30% better control for the spread of VOCs when compared to international standards. This effort has made SCG a role model for VOCs management in related industries.
Mercury is created from the cement manufacturing system mainly from raw materials and fuel used in the process. Therefore, the amount of mercury emission relies greatly on the portion of raw materials as well as the type and source of the fuel.
SCG Cement-Building Materials has announced internal criteria regarding mercury emission and has controlled the quality of industrial waste, renewable raw materials, and fuel in the kilns.
In SCG’s cement plants, mercury emission is monitored to be within legal standards with at least 2 investigations per year. Moreover, data on mercury emission is reported in the Environmental Impact Assessment or EIA report.
- Within 2025, reduce dust emission 8% compared with BAU at base year of 2020
- Set targets of air pollution emission according to international norms among peers, and not exceed legal limits
- Use best-in-class technology solutions in managing and reducing air pollution, aiming at both prevention at source and emission, as well as continuous inspection of air quality
- Foster collaboration in air pollution management with community and stakeholders. And collect feedbacks and concerns regularly.
- Reduction of dust emission 11.34% compared with the base year of 2020
Initiatives to reduce air emissions
R&D of SO2 Absorption
In 2021 SCG launched a project to study absorbents that can effectively reduce SO2 emission and which can be applicable on site at factories. The project researched into correlation of properties of such absorbents such as surface, size and pores, number of active sites per SO2 trapping performance.
The purpose is to reduce SO2 emissions that exceed benchmark and to reduce cost of absorbents. The research also considers absorbents of lime mud which is waste from internal production process in view of the circular principle whereby waste is recovered and waste disposal cost reduced. Results of this research project will provide guidance regarding types of absorbents that are appropriate to a factory’s context for effective reduction of SO2 emissions.
Controlling VOCs Leakage at All Point Sources
Volatile Organic Compounds (VOCs) in petrochemical industry originate from raw materials, products and by-products. Some VOCs bring health impact to bear upon health of those coming into contact with them. SCG Chemicals has developed a VOCs Inventory conforming with the announcement of the Department of Industrial Works, Ministry of Industry Thailand. The Inventory covers comprehensively all point sources of VOCs ranging from storage tank, product, delivery of raw materials or product, wastewater treatment system, post-combustion residues at the incinerating tower, and the company has taken measures to control potential VOCs leakage continuously including:
- Installation of high-performance pollution treatment system such as the Vapor Recovery Unit at storage tanks and vessel loading, and to recover VOCs back into production system.
- Installation of Internal Floating Roof for naphtha raw materials to replace the previous line of tanks where leakage may occur around the lid area, and as such minimizing VOCs leakage.
- Reduction of hydrocarbon combustion at tower through Flare Minimization project, by sending hydrocarbon that must be burned from one factory to be used as substitute material at another factory.
- Conducting Leak Detect and Repair (LDAR) at joints, valves, pipe connection parts, to reduce seepage from equipment regularly.
- Applying Turnaround procedures of petrochemical industry into the maintenance of all factories regardless of partial equipment or major turnaround maintenance where there is risk of VOCs leakage.