Verifying Chemical Conversion Yield Deductions under ISO 22095 Standards
Chemical conversion yield deductions under ISO 22095 mandate subtracting process gas, char, and hydrotreating losses from input mass before awarding credits.
Mass Allocation Model
Meaning
Mathematical framework used to attribute specific properties or sustainable characteristics to products derived from a mixed feedstock stream. Implementing a mass allocation model allows chemical plants to co-process recycled oil with virgin naphtha without needing separate production lines. The logic dictates how the environmental benefits of the waste feed are divided among the various output chemicals like ethylene or propylene.
Property Assignment
Free attribution represents one end of the spectrum where credits are moved to the most valuable products. A more restrictive mass allocation model requires that the credits follow the physical carbon atoms through the chemical reactions. These rules define the maximum amount of recycled content that a molder can claim on a finished part.
Feedstock Ratio
Calculations occur within a defined site or across a group of interconnected facilities. The mass allocation model tracks the flow of material from the moment it crosses the site gate until it leaves as a finished product. Losses during the reaction must be subtracted to ensure the total output never exceeds the input.
System Boundary
Buyers rely on this data to meet their corporate sustainability targets. Because the molecules are chemically identical, the mass allocation model is the only way to differentiate a circular polymer from a conventional one.