Global SOx Scrubber Market Outlook, 2031

Sulphur oxide scrubbers remain one of the largest and most policy-sensitive technologies in air pollution control. They remove sulphur dioxide by bringing flue or exhaust gas into contact with an alkaline reagent, with wet limestone forced-oxidation FGD, the workhorse of large coal plants, achieving removal efficiencies of 95% to 99% and producing wallboard-grade gypsum. A single large coal unit can consume several hundred thousand tonnes of limestone a year. Seawater, ammonia, caustic and magnesium systems serve coastal, fertiliser-linked and smaller industrial sites, while circulating dry scrubbers and dry sorbent injection suit water-scarce locations. At sea, the IMO's global sulphur cap fell from 3.50% to 0.50% on 1 January 2020, triggering a wave of retrofits that took the global fleet fitted with exhaust gas cleaning systems to more than 5,000 ships, mostly large tankers, bulk carriers and container ships. China installed FGD on almost all of its coal power capacity by the late 2010s and extended ultra-low emission rules to steel from 2019. Industrial applications account for roughly three quarters of scrubber demand and marine for about a quarter, and Asia-Pacific accounts for more than half. Suppliers include Mitsubishi Heavy Industries, Babcock & Wilcox, Andritz, Valmet, Doosan Lentjes, Thermax and Longking, and marine specialists Wärtsilä, Alfa Laval and Yara Marine.


The demand outlook has been rewritten by policy shocks in quick succession. India's 2015 norms required every coal plant to install FGD by 2017, but by December 2024 only a small minority had complied, and on 11 July 2025 the environment ministry exempted Category C plants, roughly three quarters of the country's coal capacity of around 218 gigawatts, leaving only Category A plants near major cities with a firm mandate. In the United States, the EPA proposed in June 2025 to repeal the 2024 amendments to the Mercury and Air Toxics Standards. At sea, however, regulation is tightening: the Mediterranean became a sulphur emission control area in May 2025 with a 0.10% limit, the Canadian Arctic and Norwegian Sea ECAs entered into force in March 2026 with 0.10% limits applying from March 2027, and OSPAR states agreed in July 2025 to ban open-loop scrubber discharges from July 2027 and all scrubber discharges in ports and inland waters from 2029, pushing owners toward hybrid systems. Growth through 2031 will therefore lean on steel, non-ferrous smelting, waste-to-energy, aftermarket services for thousands of ageing FGD units installed in the 2000s and 2010s, and marine hybrid conversions rather than new coal power.

Drivers Air Quality Regulation and Industrial Ultra-Low Emissions Sulphur dioxide causes acid rain, respiratory illness and fine particulate formation, and governments set emission limits for power plants, steel mills, smelters, cement kilns, refineries and incinerators. China's ultra-low emission requirements for steel, coking and other industries, EU best available technique conclusions, US Clean Air Act programmes and standards in Southeast Asia, the Middle East and Latin America drive scrubber installations and upgrades. Waste-to-energy plants require acid gas scrubbing.
Shipping Sulphur Rules and Fuel Price Spreads The IMO's global 0.50% sulphur cap and 0.10% limit in emission control areas, including the Mediterranean since May 2025 and new Arctic and Norwegian ECAs from 2027, require ships to use low-sulphur fuels or scrubbers. When the price spread between high-sulphur and compliant fuels are wide, scrubbers pay back quickly, encouraging installations on large vessels.


Challenges Coal Phase-Outs and Policy Rollbacks Coal plant retirements in Europe and North America reduce demand for new power plant FGD, and policy changes such as India's July 2025 exemption of most coal plants from FGD and US proposals to repeal 2024 MATS amendments cut expected demand. Climate policies discourage new coal capacity in many countries, limiting long-term growth.
Costs, By-Product Management and Discharge Restrictions Scrubbers are capital-intensive and consume reagents, water and energy, and they generate wastewater and by-products such as gypsum that must be sold or disposed of. Marine open-loop scrubbers face growing discharge bans in ports and coastal waters, such as the OSPAR ban from 2027, requiring hybrid or closed-loop systems. Corrosion and maintenance add costs.


Trends Multi-Pollutant and Dry Systems for Industry Industrial users increasingly adopt systems that remove SOx together with particulates, mercury, acid gases and NOx, such as circulating dry scrubbers combined with fabric filters, and integrated systems for steel sintering and waste incineration. Dry and semi-dry technologies avoid wastewater and are favoured for smaller units and water-scarce regions. Ammonia-based scrubbers producing fertiliser by-products are used in China.
Hybrid Marine Scrubbers and Carbon Capture Integration Shipowners choose hybrid scrubbers that can operate in closed-loop mode where open-loop discharge is banned, and suppliers are developing scrubbers integrated with onboard carbon capture. Washwater treatment and particulate removal are improving to meet environmental concerns.




Wet scrubbers account for roughly 70% of industrial SOx scrubber installations because they achieve removal efficiencies above 95% to 99% at large scale, use inexpensive limestone or seawater and produce saleable by-products such as gypsum and ammonium sulphate. Wet limestone forced-oxidation flue gas desulphurisation is the dominant technology for large coal-fired power plants and many industrial boilers, spraying limestone slurry into absorber towers where sulphur dioxide reacts to form calcium sulphite that is oxidised into gypsum. The gypsum is dewatered and sold to wallboard and cement producers, offsetting part of the reagent cost. Seawater scrubbers use the natural alkalinity of seawater and are common at coastal power plants in Asia, Europe and the Middle East, and they form the basis of open-loop marine systems. Ammonia-based scrubbers, widely installed in China, produce ammonium sulphate fertiliser and suit plants located near ammonia supply. Caustic and dual-alkali scrubbers using sodium hydroxide serve smaller industrial boilers, chemical plants and closed-loop marine systems where compact design and high efficiency matter. Magnesium hydroxide scrubbers are used in some industrial and marine applications. Semi-dry spray dry absorbers inject lime slurry that evaporates in the flue gas, producing a dry by-product collected in fabric filters, and they suit medium-sized boilers and waste incinerators. Circulating dry scrubbers recirculate lime-based sorbent in a fluidised reactor, achieving high efficiency without wastewater and increasingly favoured in water-scarce regions. Dry sorbent injection of trona or hydrated lime is the lowest-capital option for moderate removal and is used at smaller units and as a supplementary control. Marine wet systems come in open-loop, closed-loop and hybrid configurations, with hybrid designs now the default for new installations because of spreading discharge bans. System choice is driven by unit size, fuel sulphur content, water availability, by-product markets and space constraints at existing plants.


Industrial applications account for about 75% of SOx scrubber demand because power plants, steel mills, smelters, cement kilns, refineries and incinerators burn or process sulphur-bearing materials continuously and face binding emission limits under national air quality laws. Industrial demand accounts for about three quarters of SOx scrubber installations by gas volume treated. Power generation remains the largest industrial application, particularly coal and lignite plants in China, India, Indonesia, Vietnam and other developing economies, although India's July 2025 exemptions and coal retirements in Europe and North America are reducing its share. Steel sintering and pelletising plants are major users in China, where ultra-low emission requirements introduced in 2019 drove extensive retrofits, and in India, where steel capacity is expanding rapidly toward a national target of 300 million tonnes. Non-ferrous smelters producing copper, zinc, nickel and lead capture concentrated SO₂ in acid plants and use scrubbers for tail gases, with smelting capacity growing to meet energy transition metal demand. Cement kilns using high-sulphur fuels or raw materials install scrubbers or dry sorbent injection to meet limits. Refineries scrub emissions from fluid catalytic cracking units, sulphur recovery tail gas and process heaters. Waste-to-energy and hazardous waste incinerators use semi-dry and wet scrubbers to remove SO₂ together with hydrogen chloride and other acid gases, and this segment is expanding in China, Southeast Asia, the Middle East and Europe. Pulp and paper mills, chemical plants and glass furnaces form additional users. Marine applications account for about a quarter of demand, with more than 5,000 ships fitted since 2015, covering container ships, tankers, bulk carriers, cruise ships and ro-ro vessels, where demand depends on the price spread between high-sulphur and compliant fuels and the expansion of emission control areas. Glass, ceramics and fertiliser plants form smaller but steady users, particularly in Asia and Europe, where industrial permits specify SO₂ limits tied to best available techniques.


Limestone and lime are the most widely used SOx scrubber reagents because they are abundant, inexpensive and well proven in large absorbers, while seawater, sodium, ammonia and magnesium reagents serve coastal, compact, fertiliser-linked and marine applications. Limestone is the reagent of choice for large wet FGD systems, accounting for the majority of global reagent tonnage, because it is cheap, widely quarried and produces gypsum of wallboard quality when systems are designed for forced oxidation. Reagent consumption is substantial, with a large coal unit using several hundred thousand tonnes of limestone a year, creating long-term supply contracts for quarry operators such as Carmeuse, Lhoist and Graymont. Lime, produced by calcining limestone, is more reactive and is used in spray dry absorbers, circulating dry scrubbers and some wet systems, although it is more expensive. Seawater is used without chemical purchase at coastal power plants and in open-loop marine scrubbers, but its use is increasingly constrained by discharge regulations, particularly for ships in ports and coastal waters. Sodium-based reagents, including caustic soda, sodium carbonate, trona and sodium bicarbonate, are highly reactive and used in compact industrial scrubbers, dry sorbent injection and closed-loop marine systems, with costs tied to chlor-alkali and soda ash markets. Ammonia is used in ammonia-based scrubbers, mainly in China, where the ammonium sulphate by-product is sold as fertiliser, linking scrubber economics to agricultural markets. Magnesium hydroxide offers high reactivity and lower scaling in some industrial and marine scrubbers. Regenerable processes, such as amine-based and sodium sulphite systems, recover concentrated SO₂ for conversion into sulphuric acid or elemental sulphur, reducing reagent consumption and waste, and they are used at smelters, refineries and some industrial sites. Reagent logistics, storage and preparation systems, including ball mills for limestone slurry, are significant parts of scrubber project scope and operating cost.

New installations account for a large share of SOx scrubber demand because new plants, smelters, incinerators and newbuild ships in Asia and the Middle East need complete systems, while retrofits and aftermarket services grow in mature markets. New installations account for an estimated 45% of SOx scrubber demand, concentrated in coal power and industrial projects in China, Southeast Asia and India, waste-to-energy plants across Asia and the Middle East, and newbuild ships at Chinese, South Korean and Japanese shipyards. Turnkey systems for large power units take two to four years from award to commissioning, so project timing strongly influences annual order intake. Retrofits on existing plants and ships account for around 30% of demand, historically driven by China's ultra-low emission programme and the marine retrofit surge around IMO 2020, and now increasingly by steel and non-ferrous industry upgrades and ships trading in new emission control areas. Upgrades to existing scrubbers, including absorber modifications to raise removal efficiency, conversion of open-loop marine systems to hybrid operation, addition of wet electrostatic precipitators for fine particles and integration of mercury and acid gas controls, form a growing segment. Aftermarket services, including spare parts such as pumps, spray nozzles, mist eliminators and linings, reagent supply, maintenance contracts, performance testing and digital optimisation, account for around 25% of demand and provide recurring revenue that is less cyclical than project sales. The installed base of thousands of FGD units and more than 5,000 marine scrubbers worldwide is ageing, increasing replacement of corrosion-damaged components and control system upgrades. Suppliers increasingly offer long-term service agreements and remote monitoring to capture lifecycle value. Digital tools such as real-time pH control, reagent optimisation and predictive maintenance are increasingly bundled with service contracts. Service revenue is especially resilient in China, where thousands of FGD units installed in the 2000s and 2010s now require major refurbishment, absorber relining and control upgrades.


Asia-Pacific is the largest SOx scrubber market, accounting for more than half of global demand, led by China and India, while Europe and North America focus on upgrades, waste-to-energy and marine systems. Asia-Pacific accounts for more than half of global SOx scrubber demand, led by China, which installed FGD on nearly all coal power capacity and continues to apply ultra-low emission requirements to steel, coking, cement and non-ferrous industries, with domestic suppliers such as Longking and state engineering groups dominating. India's FGD market, once expected to be one of the world's largest, contracted after the July 2025 notification exempting Category C plants, about three quarters of coal capacity, though Category A plants near major cities must still comply and case-by-case decisions apply to Category B. Southeast Asia, including Indonesia, Vietnam and the Philippines, installs scrubbers on new coal plants and industrial facilities, and Japan and South Korea have mature markets and major shipyards installing marine scrubbers. Europe is a significant market, with strict industrial emission standards, waste-to-energy plants, marine scrubber suppliers such as Wärtsilä, Alfa Laval, Yara Marine and Valmet, and emission control areas in the Baltic, North Sea and, since May 2025, the Mediterranean, while coal phase-outs reduce power plant demand. North America has declining coal FGD demand, with the EPA proposing in June 2025 to repeal 2024 MATS amendments, but steady demand from industrial sources, waste-to-energy and ECAs. The Middle East uses seawater FGD at oil-fired and coal plants and scrubbers in refining and smelting, and Latin America and Africa have growing demand from mining, smelting and power.

• March 2026 – Canadian Arctic and Norwegian Sea emission control areas enter into force: New MARPOL emission control areas took effect, with 0.10% sulphur limits applying from March 2027, increasing the value of marine SOx scrubbers for ships trading in these waters.
• July 2025 – India exempts most coal plants from FGD requirements: India's environment ministry revised SO2 norms, exempting Category C coal plants, about three quarters of capacity, from installing flue gas desulphurisation and shifting Category B plants to case-by-case review.
• July 2025 – OSPAR parties agree to ban open-loop scrubber discharges: North-East Atlantic countries agreed to ban open-loop scrubber discharges from July 2027 and all scrubber discharges in ports and inland waters from 2029.
• June 2025 – US EPA proposes repealing 2024 MATS amendments: The EPA proposed to repeal tighter 2024 Mercury and Air Toxics Standards amendments for coal plants, reducing pressure for new emission control investments.
• May 2025 – Mediterranean Sea becomes a sulphur emission control area: Ships in the Mediterranean had to use 0.10% sulphur fuel or equivalent scrubbers, increasing the economic case for marine scrubbers.
• January 2020 – IMO 2020 global sulphur cap takes effect: The global limit on marine fuel sulphur content fell from 3.50% to 0.50%, triggering a wave of marine scrubber installations.



Considered in this report
• Historic Year: 2020
• Base Year: 2025
• Estimated Year: 2026
• Forecast Year: 2031

Aspects covered in this report

• Global SOx Scrubber Market with its value and forecast along with its segments
• Various drivers and challenges
• Ongoing trends and developments
• Top profiled companies
• Strategic recommendation

By Technology
• Wet Limestone FGD
• Seawater Scrubbers
• Ammonia-Based Scrubbers
• Caustic and Dual-Alkali Scrubbers
• Spray Dry Absorbers
• Circulating Dry Scrubbers
• Dry Sorbent Injection
• Marine Open-Loop, Closed-Loop and Hybrid Scrubbers

By Application
• Power Generation
• Steel and Sintering
• Non-Ferrous Smelting
• Cement
• Refineries and Chemicals
• Waste Incineration
• Marine

By Reagent
• Limestone
• Lime
• Seawater
• Sodium-Based Reagents
• Ammonia
• Magnesium Hydroxide

By Installation Type
• New Installations
• Retrofits
• Upgrades
• Aftermarket Services