Biofine Hydrolysis Process and Derivative Product Upgrading Technologies 191
yields varied from 69% to 77%. For tobacco chops, lower yields were obtained for
sulfuric acid solution (about 13%–14% based on the cellulose content and 17%–21%
based on the theoretical yield) than for hydrochloric acid solution (about 21% to as
high as 59% based on the cellulose content and 29%–82% based on the theoretical
yield). The optimization of the main operating parameters mentioned earlier allowed
an increase of yield up to 83% of the theoretical yield. The use of microwave improved
the catalyst performance with significant energy and time saving. The hydrothermal
conversion of soluble inulin and wheat straw/water slurry to LA in the presence of a
heterogeneous niobium phosphate catalyst also gave favorable results.
7.3 UPGradinG OF intermediate PrOdUCts
FrOm the BiOFine PrOCess
Three most important products resulting from the hydrolysis of cellulosic materials are
furfural (or HMF), LA, and GVL. The process also produces two coproducts: formic
acid and ligneous char. Both of them have significant market values. Furfural is produced from the hydrolysis of five-carbon sugars and LA is produced from the hydrolysis
of six-carbon sugars as well as from HMF. The GVL is produced from LA and it is a
very good feedstock for various kinds of fuels. LA produced from the Biofine process
has two highly reactive functional groups (as shown in Figure 7.6) that allow a great
number of synthetic transformation. LA is readily soluble in water, alcohols, esters,
ketones, and ethers. It can react as both a carboxylic acid and a ketone [24–27]. Due
to the special relationship of the carboxylic and ketone groups, many of the reactions
proceed with cyclization to form heterocyclic molecules such as methyltetrahydrofuran (MTHF). A vast number of derivatives are possible from the LA as a platform
chemical [24–27]. As shown by Hayes et al. [8] and others [23–28], the intermediate
products from the Biofine process, namely, LA, formic acid, furfural, and char containing lignin, can be upgraded to numerous products that can be used in five separate
markets [8,23–28]:
1. Energy and Fuel Industries
The products can be upgraded and used for heating and turbine fuels, gasifier fuels, and electric power. In this respect, Biofine char has a significant
heating value. The products can also be upgraded to make MTHF, methyl
and ethyl levulinate (fuel additives), jet fuel, fuel esters, and hydrocarbons
useful for fuel industries.
2. Specialty Chemical, Pharmaceutical, and Polymer Industries
LA, angelica lactone, delta-aminolevulinic acid (DALA), ketals, and others
are used for specialty chemical and pharmaceutical products. The products
can also  be  upgraded to monomers and polymers such as epoxies, polycarbonates, diphenolic acid (DPA), GVL, tetrahydrofuran (THF), succinic
acid, and furans.
3. Agricultural Industry
The coproducts such as formic acid and the upgraded products such as
DALA and DPA have agricultural usages. Biochar can be used as a soil
conditioner.