Small-Scale Ammonia Production from Biomass: A Techno-Enviro-Economic Perspective

Ammonia
production has traditionally been based on large-scale
plants. The thrust toward large-scale production to gain economic
advantages has overshadowed the benefits that could be derived from
small-scale production plants. Additionally, the ammonia industry
consumes a major chunk of global fossil fuels, which also burdens
the planet with greenhouse gases. To effectively counter these issues,
this study investigates the production of ammonia from biomass. Processes
based on biomass plants are usually small-scale and are limited by
biomass supply. To ensure sustainable ammonia production, this study
tries to highlight the techno-economic advantages that result from
small-scale ammonia plants based on biomass feedstock. This paper
proposes a new process that takes inputs from a relatively old, natural
gas based process (leading concept ammonia) specifically designed
for small-scale ammonia manufacture and couples it with a recently
developed dual fluidized bed technology for biomass feedstock. Two
different flowsheet configurations are simulated rigorously and compared
to gain a better understanding of the process. The flowsheets are
optimized, and energy integration is performed to provide a wider
insight. The life cycle assessment calculations that are carried out
using ASPEN Plus simulation results and ecoinvent databases predict
a CO2 emissions reduction of 54–68% when compared
to conventional ammonia plants.