Combining catalytical and biological processes to transform cellulose into high value-added products

Abstract

<jats:title>Abstract</jats:title><jats:p>Cellulose, the most abundant polymer of biomass, has an enormous potential as a source of chemicals and energy. However, its nature does not facilitate its exploitation in industry. As an entry point, here, two different strategies to hydrolyse cellulose are proposed. A solid and a liquid acid catalysts are tested. As a solid acid catalyst, zirconia and different zirconia-doped materials are proved, meanwhile liquid acid catalyst is carried out by sulfuric acid. Sulfuric acid proved to hydrolyse 78% of cellulose, while zirconia doped with sulfur converted 22% of cellulose. Both hydrolysates were used for fermentation with different microbial strains depending on the desired product: Citrobacter freundii H3 and Lactobacillus delbrueckii, for H</jats:p>

Significance and Challenges of Biomass as a Suitable Feedstock for Bioenergy and Biochemical Production: A Review

“…Conversion of biomass to biofuels by combined catalytic and biological processes (Adapted from[76]). …”

Impact of Design on the Activity of ZrO2 Catalysts in Cellulose Hydrolysis-Dehydration to Glucose and 5-Hydroxymethylfurfural

“…5-HMF yield reached 3.76% at 1.4 MPa autogenic pressure, 463 K and cellulose conversion 52.18%. Gavilà et al [41] reported transformation of microcrystalline cellulose to 5-HMF at 453 K, pressure 3 MPa. The selectivity of the target product was ~20.6%.…”

“…Table 1 presents data on the processing of cellulose and cellulose-containing biomass in the presence of catalysts based on ZrO 2 . In general, in the presence of the proposed catalytic systems, the yields of glucose and 5-HMF can reach 12.7 and 20.6%, respectively, at temperatures of 453-523 K [38][39][40][41][42][43][44][45]. The use of a cocatalyst such as sulfuric acid can improve the efficiency of the dual catalyst system.…”

“…It should be emphasized that the catalysts reported elsewhere were prepared by various methods such as precipitation [40,45], calcination [44], the sol-gel method [40], hydrolysis followed by calcination [43], and precipitation in combination with mechanical activation [46]. Commercial ZrO 2 was also used [41,47]. Various precursors of ZrO 2 (zirconyl chloride, zirconium dioxide hydroxide, zirconium propoxide) were applied.…”

Improvement of Biohydrogen and Usable Chemical Products from Glycerol by Co-Culture of Enterobacter spH1 and Citrobacter freundii H3 Using Different Supports as Surface Immobilization

“…In this paper we also aimed to assess the effectiveness and feasibility of the surface cell immobilization of a co-culture (1:1) of Enterobacter and Citrobacter sp on four different porous solid supports: maghemite (Fe 2 O 3 ), activated carbon (AC), silica gel (SiO 2 ) and alumina (γ-Al 2 O 3 ) via batch dark fermentation. These supports are selected because they have been proven to provide good surface area attachment sites in catalytic processes and cell immobilization [35,36]. Some previous studies also show these kinds of supports will stimulate cell growth and hydrogen production, provide buffer capacity, and enhance cell retention times.…”