CO2-negative biomass conversion: an economic route with co-production of
green hydrogen and highly porous carbon
Abstract
The global consensus of carbon neutralization calls for new ideas of CO2
capture, conversion and utilization, especially CO2-negative
technologies. In this work, a CO2-negative process was developed to
convert three different types of biomass species into valuable products,
green hydrogen and activated carbon (AC). Four reaction modules
including pyrolysis, activation, gasification, and chemical looping were
integrated and balanced in terms of mass and energy. After optimization,
green H2 with up to 95.54% purity can be produced with price as low as
$3.10/kg. The solid AC product can fix 10-20 wt% of carbon element
from biomass to achieve a similar proportion of reduced CO2 emission.
Part of the separated CO2 can be reused in the activation process and
converted to CO product for internal use. Overall, this process
demonstrates an economic route for biomass conversion with the
co-production of green hydrogen and value-added AC products. Moreover,
CO2-negative emission is also realized.