From the archive: Taimur Burki on Chemical Reclamation and Reuse

View the recording here. Intel’s Responsible Inclusive Sustainable Enabling (RISE) goals for 2030 include a goal to upcycle 60% of manufacturing waste streams into the circular economy, with zero waste to landfill. To ‘upcycle’ the waste, sites must recover, directly reuse, or recycle waste. Taimur Burki highlights that each new process in semiconductor manufacturing requires more chemicals, yet there are several boundaries to greater recycling. One of these challenges is the US regulations related to the recovery of chemical waste pose challenges for these goals.

US regulations outline that hazardous materials can be reclaimed or reused if one of these conditions is met: the entire material is managed as a valuable commodity for reuse in manufacturing processes; the material is used to produce a valuable product or intermediary material; or the material directly substitutes another material.

To encourage chemical recycling, the US Environmental Protection Agency (EPA) recently introduced new regulations: materials can be recycled if they are reclaimed under the control of the facility generating the waste; materials can be transferred to another company under certain conditions; or certain spent solvents can be transferred for remanufacture. As such, new opportunities for chemical recycling have opened.

Burki explores a case study in which the new regulations allowed successful reclamation of sulfuric acid from wafer cleaning processes. A stream which contained 80% sulfuric acid and 2% hydrogen peroxide aqueous solution was segregated at the tool and drained into a tank system. The segregation was performed to make meeting wastewater discharge limits easier, and because it reduced the volume of caustic required for neutralizing the stream. However, it was expensive and less environmentally sustainable to transport sulfuric acid to a hazardous waste landfill. Collaborating with regulators and waste vendors, the fab found a third party that could use the chemical waste as a valuable commodity in accordance with the regulations and managed to achieve a return on investment from the infrastructure and tank systems required for reclamation.

However, for other waste streams, there are still many challenges. Regulations mean that open flames cannot be used to reclaim hazardous materials, and as such the methods which can be used in reclamation are limited. In addition, distillation methods can interfere with fab air permits for emissions. Burki finishes his presentation by encouraging the industry to think further about how the new regulations can allow for greater chemical recycling in fabs.

For more details on the case study, as well as additional details on the challenges of reclaiming chemicals under closed loop systems, view the full presentation with Q&A here.