Steam Cracking Technologies

Steam cracking technology

Adding value through sustainable and smart technologies

Steam crackers are large and complex units at the heart of petrochemical complexes, producing the important building blocks ethylene, propylene, butadiene, aromatics and acetylene. They involve cracking hydrocarbon feedstocks in the presence of steam and at temperatures of between 800° and 870°C. The resulting cracked gas is separated into valuable products such as ethylene, propylene, acetylene, butadiene, pyrolysis gasoline and BTX, all according to the specifications required for downstream processes.
Linde Engineering is one of the few technology contractors worldwide that can deliver technology, engineering, procurement and construction (T-EPC) services for the entire ethylene plant along with downstream units, utilities and offsite units. The highest CAPEX efficiency as well as low energy consumption have always been the focus of our designs. Our strength lies in providing tailor-made solutions engineered to best meet our customer’s requirements. Our offering includes a toolbox and methodology for greenhouse gas emission reductions and improved carbon management to support our customers’ sustainability roadmaps.
To date, we have licensed and/or built more than 70 plants around the world.

Setting the benchmark in steam cracking

The technology for steam cracking was developed over 70 years ago. Since then, we have continually scaled it up and optimized it to fully meet today's and tomorrow’s most stringent safety, economic and environmental/climate protection requirements. We are proud that we were the first contractor to license and build a series of ethylene plants with capacities of 1,500 kilotons/annum (kta). Since then, we have expanded our references to include plants that produce as much as 2,300 kta of ethylene.

Cracking furnace technology

Our cracking furnaces deliver outstanding ethylene selectivity, capacity, runtimes and energy efficiency. Customers also frequently quote highest process safety, ease of operation and robustness as key success factors. Designed to support any feedstock scenario and combination, our furnaces convert raw materials such as ethane, liquefied petroleum gas (LPG), butane, naphtha, atmospheric gas oil (AGO), hydrocracker residue, bio-naphtha, bio-diesel and plastic waste pyrolysis oil with end boiling points up to 580°C into ethylene and valuable by-products by means of thermal cracking (pyrolysis).
In recent years, we have designed cracking furnaces with capacities in excess of 250 kta to meet ever-growing demand for ethylene. Our proprietary technologies utilize the latest coil geometries and metals, proprietary air preheating concepts, next-generation ultra-low-NOx burners and catalytic DeNOx systems to keep emission levels below national and international regulations, maximize yields and minimize energy consumption.

Linde Virtual Furnace
Linde Virtual Furnace, Optimizing furnace operational efficiency in real-time

Smart cracking furnace – solutions to improve furnace operations

In the recent years, Linde has invested substantial effort into the development of digitalization and automation technologies for Linde cracking furnaces and can now offer the most modern and advanced solutions to boost furnace operation and efficiency. These innovations offer various technical and business benefits, resulting in enhanced plant performance overall.
The Linde Virtual Furnace (LVF) is a set of software modules that model a live furnace based on the design blueprint. Using kinetic modelling, this “digital twin” simulates key performance and operational parameters, calculating more than 2000 possible reactions in the case of steam cracking furnaces, for instance. This means it covers the entire radical chain reaction involved in cracking hydrocarbons containing up to 140 components. These simulations give operators key performance and condition indicators, enabling them to fine-tune operations. Thermal imaging can be added to provide online measurements of tube temperatures so operators can avoid overheating and hot spots.
Automatic mode change enables automatic transfer between all operating modes. This avoids downtime due to timing issues and prevents the plant from running in the wrong mode. All of which contributes to plant safety.

Ethylene separation technology

The separation train of an ethylene plant is a very complex process sequence. Our engineering experts work closely with our customers to optimize every step in this process flow with a view to maximizing return on investment and minimizing energy consumption. Depending on the feedstock, target yield and product specifications, we tailor our superior steam cracking and ethylene separation technologies to customer-specific demands. Customers can thus rely on our ethylene plants for the highest process safety, lowest CAPEX, best OPEX, high availability, robustness and ease of operation/maintenance. As a leading ethylene licensor and T-EPC contractor, our one-stop service includes all necessary sublicenses so customers can look forward to a seamless, end-to-end cracker design. 

Multi-Step Process
Downstream of a cracking furnace, the separation train of a cracker starts with the “hot” section, where the cracked gas is quenched and cooled down to ambient conditions, heavy fractions are condensed and separated, and the process steam is condensed and removed for reuse. The cracked gas then enters the compression section, where it is typically compressed in four to five stages up to a pressure of approximately 36 bar. The compressed, cracked gas is dried and cooled before being separated into the C2- fraction, which is routed to the cold section for further separation, and into the C3+ fraction. C2- and C3+ fractions are then separated in sequential steps into the specified products. Unwanted impurities like acetylene and methylacetylene/propadiene are hydrogenated to ethylene and propylene. Pyrolysis gasoline must also be hydrogenated in order to meet market specifications. In some cases, certain fractions (e.g. ethane, propane and butane/butenes) are recycled back to the furnaces in order to improve the overall product yields.

Ethylene Separation Technology

Linde value cracking

Plant operators are always eager to increase profitability and remain competitive in the marketplace. We have developed an innovative solution to maximize the yield of high-value components such as propylene and butadiene. It combines mild or extremely mild cracking severity conditions with a toolbox containing various operational and technical measures aimed at optimizing the processing and treatment of recycle streams. Suited to both new and revamp projects, this proprietary, state-of-the-art technology provides customers with the benefit of optimized plant economics.

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Revamps & Operational Support

Revamps & operational support

For many decades now, customers have been relying on our strong commitment to operational support. We help optimize plant operations after start-up, offer operator training, and deliver various debottlenecking, capacity expansion and feedstock change and upgrade services to meet new emissions and environmental requirements and regulations. Our strong track record in the execution of revamp projects clearly demonstrates our solid understanding of the specific challenges involved in this type of project where, besides sound cost control, schedule adherence to meet turnround windows is key. Our front-end loaded engineering concept ensures highest and earliest stability for flawless project execution.

Sustainable solutions for emissions reduction & circularity

We support our customers in the petrochemical industry on their journey towards greater sustainability. Our expertise and experience enable them to accelerate their efforts to reduce greenhouse gas (GHG) emissions, liquid effluents and solid waste, and to drive the change to a circular economy by processing recycled material.

Our holistic approach is based on a methodology specifically developed to assess steam crackers and entire petrochemical sites. Combined with a broad toolbox of dedicated technical solutions for either avoidance/reduction or elimination, we help to optimize carbon management and sustainability in existing and newly built facilities by focusing on the following:

  • Energy and/or GHG intensity reduction (Scope 1 and Scope 2) and increased efficiency
  • Processing of renewable/alternative feedstocks (e.g. bio-naphtha, pyrolysis oil from plastic waste)
  • Steam cracker electrification and site integration
  • Advanced cracking furnace and firing concepts (gas turbine integration, air-preheating, hydrogen firing, electrical furnace)
  • Post-combustion carbon capture, storage and re-utilization in chemical processes (CCS and CCU
  • Pre-combustion capture (e.g. SMR, ATR with CCS/CCU
  • EDHOX™: Alternative process for ethylene production based on the oxidative dehydrogenation of ethane 
  • Leveraging our in-depth know-how in plastic waste pyrolysis oil processing

Many factors play into the decision-making process for the best decarbonization and circularity solutions. Our tailor-made solutions always carefully balance CAPEX and OPEX, taking customer- and site- specific conditions and requirements into account. Staged implementations and hybrid architectures are often a gradual, low-risk way of distributing investment over an extended timeline. 

For more information read our success story


Sustainable Solutions
Our path to a more sustainable future

Advanced digital solutions

We have developed a set of advanced digital solutions to make life easier for plant operators. Complementing the smart cracking furnace solutions mentioned above, we also offer a variety of solutions to help our customers maximize their returns. These include:

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