Technologies that do more with lessStriking the right balance between profitability, energy efficiency and reuse carbon dioxide can be challenging. Linde has teamed up with BASF to resolve this dilemma in the steam reforming business.
New catalyst for improved steam reforming
Reducing the steam input is easier said than done, however. It would result in the formation of carbon deposits on the surfaces of conventionally used catalysts and block the key reaction, i.e. the conversion of natural gas and steam into synthesis gas. To get around this problem and improve the steam reforming process overall, including its efficiency, the specialists at Linde Engineering joined forces with the catalyst experts at chemicals group BASF. The project also brought prestigious academic partners like the Karlsruhe Institute of Technology, the Technical University of Munich, the University of Leipzig and DECHEMA Forschungsinstitut on board.
“Thanks to BASF’s strong record in catalyst research and the outstanding screening expertise of BASF’s subsidiary hte®, we were able to develop an innovative catalyst specifically for this particular challenge,” explains Virginie Lanver, BASF project manager for the development of new process catalysts. Like the conventional catalysts used to date, it is based on nickel. “The difference is that we managed to optimize the crystal structure and the exact composition of the catalyst in such a way as to suppress the formation of soot on the surfaces due to the drier conditions thanks to a kind of self-healing process,” continues Lanver. “This allows the catalyst to remain active even when the steam-to-carbon ratio drops.”
Recycling carbon dioxide to save costs
“The lower steam ratio simultaneously allowed us to produce syngas with a higher CO content – thus meeting customer-specific requirements in relation to the gas composition,” relates Bartesch. Energy efficiency is a further highlight of the DRYREF process, enabling operators to reduce CO2 emissions. In addition, surplus carbon dioxide can be recycled. “This gives us another pathway to improve the carbon balance. It is even possible to use CO2 from other processes for DRYREF,” Bartesch adds. When you factor in this CO2 import option, the cost benefits of DRYREF compared with conventional processes become even more compelling. With the above-mentioned example of a 50,000 normal cubic meter per hour syngas plant, this would mean an operating cost saving of up to twenty million dollars in the first five years of service – again when comparing a DRYREF plant with a conventional facility.
Linde and BASF established the catalyst concept and process flow of the DRYREF™ plant within the framework of a government-funded project in collaboration with academic partners (Karlsruhe Institute of Technology, the Technical University of Munich, the University of Leipzig and DECHEMA Forschungsinstitut). BASF subsidiary hte® was responsible for extensive catalyst screening in a highly efficient, high-volume test facility. The result was the SYNSPIRE™ G1-110 catalyst.
The BASF experts upscaled the production of the SYNSPIRE™ G1-110 catalyst from a few grams to a few hundred kilograms. Following extensive performance tests in the lab and at miniplants, Linde and BASF were able to confirm that the catalyst offers unique resistance to coking at a low steam-to-carbon ratio.
The Linde Pilot Reformer was installed at Linde’s Pullach site in Germany. It enabled the engineers to test the new process technologies under real-world conditions. With the help of complex measuring equipment, they were not only able to analyze the performance of the upscaled SYNSPIRE G1-110 catalyst pellets, but also test the optimized DRYREF process parameters in fine detail. This step helped to accelerate catalyst development from the lab to industry.
Linde demonstrated the commercial readiness of the DRYREF™ technology at an industrial-scale syngas plant with full product utilization.