Comment Log Display

The following comment/question was submitted via email during the
March 12th Subgroup #1 Meeting.

Name: Steve McCorkle
Affiliation: Ag Waste Solutions (AWS)

Comment: A comment was made during the meeting that biochar does
not have to be produced from a true pyrolysis process/environment
and that biochar can also be produced from gasification and/or
boilers. While technically correct, I want to point out the
following two concerns about producing biochar in California with
any process that is not a true pyrolysis process:

1. Gasification and boiler/rotary kiln systems are no longer
permittable in SCAQMD (South Coast Air Quality Management District)
and most of the Central Valley air districts, mostly due to their
NOx emissions being over the threshold of these very stringent air
districts even if they use a thermal oxidizer. The only permittable
biochar production systems in these air districts will be true
pyrolysis systems operating in the absence of air.

2. The quality of biochar produced from gasification can be
negatively impacted by the lack of temperature control and
consistency through the material during the process. Most of these
systems use a water quenching technique to cool the product rather
than an indirect cooling method. Fast heating through incineration
with air and subsequent quenching with water interrupts the
temperature control and consistency required to produce the highest
quality biochar matrix. Quenching also washes away most of the
minerals and can adversely impact the short-term nutrient release
mechanism of the biochar matrix.