(289f) Valorization of Paper Sludge to Furan Chemicals

Paper sludge has been proposed a promising sustainable chain of waste resources. It can be recovered to produce high value-added products instead of incineration or landfill. While a high content of ash, which normally ranges from 10 to 50 wt%, might be an issue for process/product development, paper sludge contains valuable carbohydrates that can be converted into biochemicals. In this work, paper sludge was treated for ash removal, prior to enzymatic hydrolysis to release sugars. When the lab-scale screen device was used to remove the ash to 1.5% from 40%, the carbohydrate conversion of 90% was achieved even at 5 mg cellulase/g cellulose. It was found that the amount and composition of ash play an important role in pH change during enzymatic hydrolysis. We have demonstrated the impacts of ash content and starting pH on carbohydrates conversion. Following enzymatic hydrolysis, dehydration of hydrolysates was conducted to produce hydroxymethylfurfural (HMF) and furfural. Since the hydrolysates contain impurities such as calcium carbonate or calcium chloride, the detailed experiments were focused on revealing the impact of these impurities on catalytic conversion. The optimization of sequential enzymatic hydrolysis and dehydration enables underutilized wet waste streams to represent valuable feedstocks for renewable sources.