Demand for coal is increasing because of the world’s growing appetite for energy. However, depletion of the highest-quality deposits and stricter emissions legislation mean that operators use lower-quality coal in more environmentally acceptable ways. Air Products' gasification processes are proven, efficient and reliable technologies. They convert a wide range of coal types to syngas that can be used:
- As an alternative feedstock for chemical manufacture (e.g., ammonia, methanol, olefins)
- To produce high-value, synthetic liquid fuels and lubricants
- To produce hydrogen
- To generate power through integrated gasification combined cycle (IGCC) processes, with lower emissions than from burning coal or even natural gas and a concentrated carbon dioxide stream for optional carbon capture and sequestration
Air Products offers the following coal gasification technology options designed to meet varying business needs:
- The Air Products Gasification Process DSC (Dry-feed Syngas Cooled) system offers high thermal efficiency suitable for large projects and IGCC power generation.
- The Air Products Gasification Process SRSC (Slurry-feed, Radiant Syngas Cooled) process offers high-quality steam production coupled with high efficiency from a slurry-feed gasifier applicable for worldscale chemical, refinery and power segments.
- The Air Products Gasification Process DBQ (Dry-feed, Bottom Quench) system uses the proven DSC reactor membrane wall and burner technology, but with a water quench configuration that reduces capital costs by up to 30% and increases feedstock flexibility.
- The Air Products Gasification Process SBQ (Slurry-feed, Bottom Quench) system uses a simple and easy-to-fabricate refractory-lined reactor, with an integrated quench section. SBQ design offers lower capital cost (up to 50%) in the solids gasification segment, while enabling shorter construction cycles and quicker plant startup. SBQ is a proven and well-commercialized design employed from a small syngas capacity to the world's biggest chemical plants.
Proven technologies that are reliable and scalable
In the dry-feed process, pulverized coal is transported pneumatically using an inert carrier gas into the gasifier, where it contacts oxygen and steam. To protect against the high gasification temperatures of up to 1600°C, a membrane wall that consists of high-pressure water/steam tubes is used. Multiple side burners and a proven swirl design allow efficient separation of the syngas from the slag. The slag flows down into a water bath, where it is extracted as a solid. The multiple burners provide the potential for easy scale-up.
The hot syngas that exits the gasifier is first quenched using ‘cold’ recycled syngas and then further cooled in an external convective cooler to generate high- and medium-pressure steam as valuable by-products. Alternatively, the hot syngas can also be cooled by direct contact with water in a bottom quench configuration.
In the slurry-feed process, the pulverized coal is mixed with water to form a slurry that is pumped into the gasifier via a single burner at the top of the reactor. Contact with oxygen starts the gasification reactions. In the slurry-feed process, the inside of the gasifier is lined with refractory bricks to protect against the high heat loads. The hot syngas and slag then pass through a quench water pool where molten solids are fused as slag and syngas is cooled while exiting the reactor.
In order to extract more useful heat from the hot syngas, a radiant syngas cooler can be applied directly at the exit of the gasifier such that the syngas is cooled and high-pressure steam is raised.
Air Products’ Turnkey Solutions
We offer these technologies either as fully Air Products-owned-and-operated syngas plants or in the form of a process license, where we can also support your project throughout its life cycle. We give customers peace of mind by providing operational support and business and project-execution services, including:
- Onsite syngas production
- Design and engineering
- Commissioning and start-up
- Experience transfer
- Master planning
- Advanced data analytics
- Technical service – retrofit/feed conversion
Why select Air Products gasification technology?
Unique and proven
Since the first coal gasifier using the Air Products Gasification Process began operating nearly 40 years ago, there are now more than 100 Air Products Gasification Process reactors operating or in the planning stages around the world. Many different coal types have been successfully processed, from highly reactive biomass and lignite to unreactive anthracites and petcoke. It is important, however, to select the proper technology for each type of feed.
Air Products’ Dry-feed Syngas Cooler and Slurry-feed Radiant Syngas Cooler technologies offer:
- Low coal consumption
- Low fresh water consumption and wastewater production
- High throughput and availability and low maintenance costs by using proven reactor membrane wall or refractory-lined wall and burner technology
- Higher thermal efficiency than other gasifiers
- High- and medium-pressure steam production, which can help reduce operating expenditures
Air Products' Dry-feed Quench and Slurry-feed Quench technologies:
- Require 30-50% less capital expenditure and offers more stable operation through its simplified configuration
- Offer higher water content in syngas, which helps certain downstream chemical production processes
Reducing capital and operational costs
The multiple-burner design is easily scaled for larger units and is highly reliable, which eliminates the need to build a spare gasifier. Using larger units requires fewer operators, less maintenance and a smaller spare parts inventory. Units with a dry coal intake capacity of 3,200 t/d are already in operation.
Continuous design improvement
As an owner and operator and through close partnerships with other users, Air Products has the insight and experience to deliver. We record innovations and improvements in a lessons-learned database for the benefit of all licensees and to improve our master design. Focusing on continuous improvement through innovation and partnership helps us to achieve longer continuous runs and lower maintenance costs.
Our global Air Products Gasification Technical Service Center provides process design, life-cycle support, simulation, and start-up assistance on the front end of projects. Long-term operational assistance, training, troubleshooting and spare parts are also offered as part of ongoing support to our customers. Lessons learned are shared through regular user meetings, as well as through global thought leadership conferences, where we seek to build user communities and accelerate learning. Ask us about our support services and arranging a site visit from some of our experts.