461
Union (EU) directive, conventional fuels must add at least 5.75% biofuels by 2010,
with a possible increment of 20% by 2020. Production of biodiesel in EU representative countries was estimated at 1.93 in 2004 and 10.37 in 2013 and surging up to
11.58 in 2016 (Fig. 1). The biodiesel production in the United States upsurged from
250 million gallons in the year 2006 to 2.89 billion gallons in 2016 [8, 9, 10]. All
the efforts have been put worldwide to boost energy efficiency and cut down greenhouse gas emissions. The high biodiesel production is accompanied by large-scale
volumes of waste, in which glycerol is the major one. For every 100 kg of biodiesel
production, 10 kg of glycerol is generated [10].
1.6
2000
1750
1500
1250
1000
750
500
250
0
1.4
1.2
1.0
0.8
0.6
Annual production (Million tons)
Price (US$ / ton)
0.4
0.2
0.0
2001 2002 2003 2004 2005 2006
Year
Glycerin Production
Refined glycerin price
Crude glycerin price
2007 2008 2009 2010 2011
Fig. 1 Global glycerol production and prices (Reproduced with permission from ref. [8], ©
Elsevier (2013))
Scheme 1 Conversion scheme of triglyceride to biodiesel and glycerol
Catalytic Conversion of Biomass-Derived Glycerol to Value-Added Chemicals