Biomass, such as agricultural straw, can be converted into briquette fuel using technology to expand the
possible applications of biomass and improve biomass utilization efficiency. The major machines
required in a briquette fuel system, such as those used for drying, chopping, briquetting, and cooling,
have become more efficient. However, a biomass briquetting fuel system requires special machines to
reach a high character index, and all units in the system must match and be combined to produce an opti-
mum system that satisfies multiple objectives, such as economy, environmental protection, stability, and
large-scale operation. In this paper, a mathematical model for a synthesized evaluation was established
according to theories of grey relational analysis (GRA) and the analytic hierarchy process (AHP). This
model was used to select a biomass briquette fuel (BBF) system scheme considering hierarchies of econ-
omy, cleanliness and environmental protection, production capacity, product quality, and production sta-
bility, along with 20 other indices, including capital investment, dust content, drying capability, briquette
rate, and the machine repair cycle. The most significant factors influencing each hierarchy were analyzed
using a sensitivity analysis. Based on the GRA and AHP theories, an optimal scheme was selected for a
fully operational 2
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t/a cornstalk briquette fuel plant in China. The optimum scheme included six
sets of briquetting machines with a capacity of 2 t/h + three sets of chopping machines with a capacity
of 5 t/h + six sets of drying machines with a capability of 2 t/h + 1 set of cooling machines with a capacity
of 12 t/h. The evaluated indices and weight coefficients were chosen objectively, and the comprehensive
and technical performances of the selected BBF system scheme improved. These results provide a
reference for the scheme selection and operation of large-scale BBF systems