The production processes of the most important basic chemicals are responsible for around 70% of the greenhouse gas emissions in the chemical industry, according to BASF. The company says it is working intensely on new technologies to substantially reduce emissions in these processes as part of its Carbon Management Program. A project team has applied to patent a process to produce methanol without any greenhouse gas emissions. If it can be successfully implemented at an industrial scale, the entire production process – from syngas production to pure methanol – will no longer release any carbon dioxide emissions, according to the company.
Typically, methanol is made from syngas, which until now has been primarily obtained from natural gas via a combination of steam and autothermal reforming. Using special catalysts, this is then turned into crude methanol, which can be further processed after purification. In the new BASF process, the syngas is generated by partial oxidation of natural gas, which does not cause any carbon dioxide emissions and has proven to be advantageous in a study jointly conducted with Linde Engineering. The subsequent process steps – methanol synthesis and distillation – can be carried out nearly unchanged, according to the company.
BASF says ingenuity was required to address the merging and processing of the waste gas streams that arise during methanol synthesis and distillation and which cannot be avoided even with optimal process management. These waste gas streams consisting of methane, carbon monoxide, carbon dioxide and hydrogen are incinerated in an oxyfuel process with pure oxygen. This results in a small volume of flue gas with a maximum carbon dioxide content. The flue gas is then scrubbed using BASF’s OASE process for full recovery of the carbon dioxide. To ensure that the carbon contained in the carbon dioxide is not lost and that it can be used again for methanol synthesis, the captured carbon dioxide is fed back into the beginning of the process. This does, however, require additional hydrogen, which BASF also aims to produce without any carbon dioxide emissions, for example, via methane pyrolysis, which is also being developed in the carbon management research program.
“We are optimistic that our climate-friendly approach will better adapt methanol synthesis to the requirements of the 21st century,” says project manager, Dr. Maximilian Vicari from BASF’s intermediates division. Vicari expects it will be around 10 years before this new process is carried out in an industrial-scale plant.
For more information, visit: www.basf.com