Sisu

What Sisu does

Sisu Energy & Environmental, LLC is a privately held Tulsa, Oklahoma-based engineering and manufacturing company that designs and supplies emissions reduction systems, waste heat recovery units, and the patented FreeHeat family of ammonia vaporization and anti-icing subsystems for combustion turbines. The company's core product is a "Single Source Solution" spanning the turbine exhaust path, from the turbine expansion joint and tempering air injection through SCR and CO catalysts, ammonia injection grids, silencers, CEMS, PLC control systems, and the stack outlet, and is delivered either as a complete integrated system to combustion turbine OEMs or as individual components and retrofits to end users and industrial facilities. Sisu markets itself as a pioneer of emissions reduction system design for combustion turbines and holds two granted US patents on its FreeHeat technology, which is claimed to save 100-200 kW per unit by replacing electric heaters and their control systems.

Sisu operates primarily as an OEM-embedded supplier to major combustion turbine manufacturers, with General Electric (LM2500 platform) as the most prominently documented customer; the company also sells directly to end users and power plant operators for retrofits, upgrades, and turnkey FreeHeat retrofits. Revenue is generated through hardware sales of new systems, custom-engineered retrofits, and aftermarket services including catalyst testing, cleaning, replacement, restacking, frame upgrades, ammonia tuning, and control system upgrades, with all pricing handled through quote-based multi-year contracts. The business is founder-led, self-funded (no institutional investment, PE, or VC involvement is evidenced), ISO 9001:2015 certified since April 2020, and operates with 11-50 employees leveraging 250+ years of combined team experience, much of it carried over from the founders' prior venture, Express Integrated Technologies.

Name

Sisu

Legal name

Sisu Energy & Environmental, LLC

Website

https://sisu-ee.com

Company type

Private

Founded year

2015

Operating status

Operating

Headcount range

11–50 employees

Short description

Sisu Energy & Environmental is a Tulsa, Oklahoma-based OEM supplier that designs and manufactures emissions reduction systems, waste heat recovery units, and the patented FreeHeat ammonia vaporization and anti-icing subsystems for combustion turbine manufacturers and power plant operators.

Ownership category

akta.pro rank

Product category

Industrial Emissions Control Systems

NAICS

Power Boiler and Heat Exchanger Manufacturing (33241), Industrial and Commercial Fan and Blower and Air Purification Equipment Manufacturing (333413)

akta.pro primary industry

Emissions Controls & Environmental Retrofit Services (SCR/FGD/ESP, CEMS) (EUAEALAL)

akta.pro secondary industry

Heat Transfer Equipment (Heat Exchangers, Boilers, Condensers) (IMAHAEAC)

Keywords

• Emissions reduction systems
• Waste heat recovery
• Combustion turbine equipment
• SCR catalyst technology
• OEM emissions equipment

Headquarters

HQ city

Tulsa

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Personnel, Operations, Technology or R&D, Marketing or Sales

Revenue model

1. Emissions Reduction Systems (OEM): OEM supplier of complete emissions reduction systems to combustion turbine manufacturers including CO oxidation, VOC destruction, formaldehyde destruction, and NOx reduction (SCR).
2. Waste Heat Recovery Units: Custom design and supply of waste heat recovery units operating independently or integrated with emissions reduction components.
3. Patented FreeHeat Systems: Sale and retrofit of patented FreeHeat Ammonia Vaporization and Anti-Icing systems for new installations and replacement of problematic electric heaters.
4. Aftermarket Services: Catalyst testing, cleaning, replacement, restacking, frame upgrades and repairs, ammonia tuning, control system upgrades, and turnkey FreeHeat retrofit installation.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels4 records

Core offering

Sisu Energy & Environmental designs, manufactures, and supplies emissions reduction systems and waste heat recovery units for combustion turbine applications. The company offers CO oxidation systems, NOx reduction via SCR catalysts, VOC and formaldehyde destruction, and the patented FreeHeat family of ammonia vaporization and anti-icing systems. As an OEM supplier, Sisu delivers single-source integrated solutions from the turbine exhaust flange to the stack outlet, complemented by aftermarket services for catalyst testing, cleaning, replacement, and retrofits.

Product overview

Sisu Energy & Environmental is a hardware-focused engineering company offering a portfolio of emissions reduction and heat recovery products for combustion turbines. The core offerings include Emissions Reduction Systems (ERS) and Waste Heat Recovery Units (WHRUs) as the main product categories, supplemented by the patented FreeHeat family of ammonia vaporization and anti-icing systems. These components—including SCR and CO catalysts, ammonia injection grids, PLC control systems, turbine expansion joints, tempering air injection systems, silencers, CEMS, ammonia vaporization skids, and flue gas distribution grids—can be integrated as a complete single-source solution or provided as standalone components. The company also provides comprehensive aftermarket services for catalyst maintenance and system upgrades. Sisu operates as an OEM supplier to major combustion turbine manufacturers including General Electric.

Differentiator

Problem solved

Functional benefit

Brands

• FreeHeat: Patented ammonia vaporization and anti-icing technology system for combustion turbine emissions reduction, designed to increase net power production and reduce maintenance

Products and services

• Emissions Reduction Systems (ERS) Complete emissions reduction systems for combustion turbines, including CO oxidation systems, VOC destruction, formaldehyde destruction, and NOx reduction via SCR catalyst technology. Supplied as OEM equipment to major combustion turbine manufacturers and as direct installations to power plant operators.
• Waste Heat Recovery Units (WHRUs) Custom-designed waste heat recovery units that can operate independently or be incorporated with emissions reduction components for power generation projects. For use by power plant operators and industrial facilities seeking to recover heat from combustion turbine exhaust.
• FreeHeat Ammonia Vaporization System Patented ammonia vaporization system for new installations and replacement of electric heaters in SCR systems. Saves 100-200 kW per unit by eliminating electric heaters and their control systems, reducing auxiliary load to increase net power production. Provides faster startups and quicker ammonia injection cycles.
• FreeHeat Anti-Icing System Patented anti-icing system with inline design that eliminates temperature resilience problems common with old heated-air systems. Utilizes an internal coil accepting both active and static modes for new installations and retrofit of failing units. Available as a standalone component or integrated with complete emissions reduction units.
• Aftermarket Services Comprehensive aftermarket support including catalyst testing, cleaning, replacement, restacking, frame upgrades and repairs, ammonia tuning, control system upgrades, and turnkey FreeHeat retrofit installation. For power plant operators and end users maintaining existing combustion turbine emissions and heat recovery equipment.

Quantifiable outcome

• 100-200 kW per unit power savings when FreeHeat replaces electric heaters and their control systems
• +2 more outcomes

Named customers1 record

Segments3 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Scale indicators3 records

Recent moves5 records

Expansion highlights4 records

Direct peers

• Anguil Environmental Systems: Anguil designs and manufactures industrial emissions control systems including thermal and catalytic oxidizers, with custom engineering and aftermarket services. It is closely comparable to Sisu in business model, scale, and the combination of emissions reduction with waste heat recovery for industrial customers.
• CORMETECH: CORMETECH manufactures SCR catalysts specifically for combustion turbine and industrial emissions applications. It directly competes with Sisu's SCR catalyst and integrated emissions reduction offerings for the same gas turbine OEM and end-user customers.
• Catalytic Combustion Corporation: Catalytic Combustion Corporation supplies emissions reduction and waste heat recovery equipment for industrial and power generation applications, including catalytic oxidizers and integrated systems. Its product scope and customer profile overlap directly with Sisu's emissions and heat recovery business.

Broad incumbents

• Mitsubishi Power: Mitsubishi Power manufactures gas turbines and supplies integrated emissions control systems as part of its turbine platforms. It is both a potential OEM customer for Sisu and a competitor offering integrated emissions solutions, but at much larger scale and with broader power generation capabilities.
• Dürr AG: Dürr AG provides environmental technology including emissions control systems for industrial applications across multiple industries. Its Clean Technology Systems division overlaps with Sisu's emissions reduction scope, but Dürr operates a much broader industrial portfolio globally.
• Johnson Matthey: Johnson Matthey is a global leader in catalyst technologies for emissions control including SCR and CO oxidation, with a much broader portfolio spanning automotive, chemical, and industrial markets. It competes with Sisu at the catalyst and emissions system layer but operates at vastly larger scale and across many end markets.
• Babcock & Wilcox: Babcock & Wilcox provides environmental systems, heat recovery, and emissions control equipment for power plants, with a broader portfolio including utility-scale boilers and service offerings beyond Sisu's combustion turbine focus. It competes at the integrated system level for similar end customers.
• Topsoe: Topsoe (formerly Haldor Topsoe) is a major catalyst manufacturer with SCR offerings for power generation and industrial emissions control. It competes with Sisu at the catalyst technology layer, but operates a much broader refining and chemical catalyst portfolio.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks7 records

Key highlights7 records

Customer concentration

• Facebookfacebook.com/SISUEnergyEnvironmental
• LinkedInlinkedin.com/company/sisu-energy-environmental

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A1 record

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sisu