Biofine Hydrolysis Process and Derivative Product Upgrading Technologies 199
3. Convert solid residue to bio-oil and biochar by pyrolysis. This process can
be enhanced by the use of formic acid produced earlier as a coproduct.
4. Upgrade bio-oil with the use of a catalyst to produce upgraded bio-oil that
is miscible with diesel.
5. Utilize the biochar as a soil conditioner or to provide fuel for the process.
This project is thus an application of the overall concept of the Biofine process
with specifically tailored upgrading of the hydrolysis products. The process is
well described by Hayes et al. [61–66] and at http://www.carbolea.ul.ie/project
.php?=dibanet.
7.4.2 BioFine ProCeSS verSuS FermenTATion ProCeSS
As indicated earlier, Biofine process is a chemical process and does not rely on
microorganism or enzymes [68,69]. The biochemical process generally produces
only alcohols and can use only a limited range of feedstock, whereas the Biofine
process can use a variety of feedstock (containing both five- and six-carbon sugars
and starch) and deliver a host of products by a suitable transformation of platform
chemicals LA and HMF.
The fermentation process takes about seven days to generate ethanol from cellulose, whereas the Biofine process takes two days for hydrolysis and about 30 min
for the production of LA. The fermentation process often gives poor yields due to
the inhibition effect of products on enzymes and microbes, whereas no such inhibition occurs in the Biofine process. The fermentation process is also very difficult
and economically unattractive for five-carbon sugars such as xylose, whereas these
sugars can give up to 50% yield to an important intermediate HMF or furfural in
the Biofine process. The contaminants in feedstock such as those in MSW and
sewage can significantly inhibit fermentation, whereas the experiments in New
York plant has shown that these feedstock can be easily processed by the Biofine
process [8]. Finally, the lignin content in biomass can affect the effectiveness of
enzymatic process due to stearic hindrance caused by lignin–polysaccharide linkages, whereas the same lignin content has no effect on the Biofine process. The
lignin content in the enzymatic process limits the access of fibrolytic enzymes to
specific carbohydrate moieties and requires steam explosion pretreatment, which
adds cost to the overall fermentation process [67]. Fundamentally, all these differences are inherent partly due to the difference in the basic nature of a biochemical
(i.e., fermentation) and a chemical (i.e., Biofine process) process.
7.4.3 BioFine ProCeSS verSuS BioForming ProCeSS
Another competing technology is the most recently developed “Bioforming process”
described in Chapter 6. The basic difference between these two technologies is the
reaction path chosen to obtain fuels, fuel additives, and chemicals. As discussed earlier, the Bioforming process can generate both gaseous (hydrogen and syngas) and
liquid fuels and chemicals, and in that sense, it offers more product upgrading possibilities. However, the intermediate platform chemicals produced by the Biofine process,