Improved enzyme technology will also be critical to making bio-based fuels and chemicals from cellulose competitive with those from corn and sugarcane, Lux Research says.
"Feedstock is the single largest driver of overall fuel production economics. While agricultural waste is a common target feedstock, municipal and industrial waste can be near zero cost, or even negative cost," said Andrew Soare, Lux Research Senior Analyst and the lead author of the report titled, "Cellulosic Chemicals and Fuels Race to Compete with First-Gen Sugar Economics." "While enzymes are a big cost driver for cellulosic sugar, methods such as supercritical fluid processes that don’t use enzymes at all can offer cheaper options," he added.
Thermochemical pretreatment options offer cellulosic sugars for USD 0.25 per kg operating cost
Lux Research analysts built a cost model for a 700,000-ton-per-year plant to study the five main routes from lignocellulosic biomass to sugars. Among their findings:
Cellulosic sugar costs vary. The minimum selling price for cellulosic sugars depends on the processes used. Dilute acid yields USD 0.34/kg, high-opex steam explosion costs USD 0.35 per kg, ammonia fiber expansion costs USD 0.36/kg, and supercritical water can yield the cheapest price of USD 0.32/kg.
Feedstock has a 21% impact on cellulosic sugar prices. A sensitivity analysis of cellulosic sugar prices found that flexing feedstock up to USD 100 per metric ton and down to USD 45 per metric ton (from a baseline of USD 70 per metric ton) had the largest impact on sugar prices, changing it by over 21%.
Eschewing enzymes yields cheapest prices. Enzymes are the most expensive variable in prices of cellulosic sugar, and supercritical fluid and concentrated acid processes don’t require enzymes at all, potentially offering the cheapest options – though technology risk remains.
The report, titled "Cellulosic Chemicals and Fuels Race to Compete with First-Gen Sugar Economics," is part of the Lux Research Alternative Fuels Intelligence and the Bio-based Materials and Chemicals Intelligence services.