eliminating the cost of nutrients and freshwater supply (Craggs et al. 2011). It has
been reported that algal cells can efficiently remove contaminating nitrogen
(N) and phosphorus (P) nutrients as well as toxic metal pollutants from
wastewaters (de-Bashan and Bashan 2010; Ruiz-Marin et al. 2010). The claims of
multiple patents, e.g., US20110247977A1, FR3023548A1, WO2014076327A1,
GB2484530A, and GB2509710A, are focused biofuel production systems coupled
with wastewater remediation. Nevertheless, to achieve desired levels of wastewater
treatment with algal systems, maximizing autotrophic production and discovering
physiological characteristics of algal cell are of primary importance and has been
the subject of the following patent: US2010267122, CN101368193A,
US20090294354A1, and US8101080B2.
To benefit all the advantageous features of coupled systems, some sustainable
systems such as HRAPs have already been developed (see ES2563852T3). HRAP
system in comparison with the conventional wastewater treatment methods requires
lower capital and operating costs and needs no intensive advanced technology to
operate compared with the conventional mechanical treatment technologies (Craggs
et al. 2012). Eight comprehensive patents could be found by searching the term
“HRAPs” in the PGPUB production database since the year 2001; for example, the
patents US20160122705A1 and US20100252498A1 discuss simultaneous methods
for HRAP-based wastewater treatment and algal production in detail.
3.2.3 CO 2 Supply
Most microalgae strains have been evolved to mitigate the environmental impacts.
This capability of microalgae strains to remove pollutants was first introduced in the
1970s and twenty years later patents such as JP4075537A, JP314777A, and
US5011604A strived to describe the details of removing pollutants from power
stations with microalgae. To facilitate the utilization of ambient CO 2 , microalgae
possess a CO 2 -concentrating mechanism (CCM) (Ndimba et al. 2013).
Nevertheless, direct CO 2 addition to medium has still been shown to significantly
enhance algal productivity. This can be simply achieved through control of pH
inhibition, reducing phosphate precipitation and nitrogen loss (mainly by reduced
ammonia volatilization), as well as by increasing nutrient assimilation into algal
biomass (Park and Craggs 2011).
Since exhaust emission gases usually include NOx and SOx, the attractive idea
of biorefining urban air harboring NOx and SOx originated from automobile
emissions was first discussed in the year 1998 by the patent US6083740A based on
the fact that gaseous pollutants such as CO 2 , NOx, and SOx can be used as nutrients
for microalgae. In the case of CO 2 supply from power stations, the pretreatment
steps such as desulfurization and setting CO 2 concentration as well as transportation
to an algal cultivation system should be taken into account (see
US20080220486A1).
Many researchers such as Chisti (2008) and Lardon et al. (2009) have emphasized that to minimize operational costs in full-scale applications, carbon dioxide
14 Recent Patents on Biofuels from Microalgae
301
been reported that algal cells can efficiently remove contaminating nitrogen
(N) and phosphorus (P) nutrients as well as toxic metal pollutants from
wastewaters (de-Bashan and Bashan 2010; Ruiz-Marin et al. 2010). The claims of
multiple patents, e.g., US20110247977A1, FR3023548A1, WO2014076327A1,
GB2484530A, and GB2509710A, are focused biofuel production systems coupled
with wastewater remediation. Nevertheless, to achieve desired levels of wastewater
treatment with algal systems, maximizing autotrophic production and discovering
physiological characteristics of algal cell are of primary importance and has been
the subject of the following patent: US2010267122, CN101368193A,
US20090294354A1, and US8101080B2.
To benefit all the advantageous features of coupled systems, some sustainable
systems such as HRAPs have already been developed (see ES2563852T3). HRAP
system in comparison with the conventional wastewater treatment methods requires
lower capital and operating costs and needs no intensive advanced technology to
operate compared with the conventional mechanical treatment technologies (Craggs
et al. 2012). Eight comprehensive patents could be found by searching the term
“HRAPs” in the PGPUB production database since the year 2001; for example, the
patents US20160122705A1 and US20100252498A1 discuss simultaneous methods
for HRAP-based wastewater treatment and algal production in detail.
3.2.3 CO 2 Supply
Most microalgae strains have been evolved to mitigate the environmental impacts.
This capability of microalgae strains to remove pollutants was first introduced in the
1970s and twenty years later patents such as JP4075537A, JP314777A, and
US5011604A strived to describe the details of removing pollutants from power
stations with microalgae. To facilitate the utilization of ambient CO 2 , microalgae
possess a CO 2 -concentrating mechanism (CCM) (Ndimba et al. 2013).
Nevertheless, direct CO 2 addition to medium has still been shown to significantly
enhance algal productivity. This can be simply achieved through control of pH
inhibition, reducing phosphate precipitation and nitrogen loss (mainly by reduced
ammonia volatilization), as well as by increasing nutrient assimilation into algal
biomass (Park and Craggs 2011).
Since exhaust emission gases usually include NOx and SOx, the attractive idea
of biorefining urban air harboring NOx and SOx originated from automobile
emissions was first discussed in the year 1998 by the patent US6083740A based on
the fact that gaseous pollutants such as CO 2 , NOx, and SOx can be used as nutrients
for microalgae. In the case of CO 2 supply from power stations, the pretreatment
steps such as desulfurization and setting CO 2 concentration as well as transportation
to an algal cultivation system should be taken into account (see
US20080220486A1).
Many researchers such as Chisti (2008) and Lardon et al. (2009) have emphasized that to minimize operational costs in full-scale applications, carbon dioxide
14 Recent Patents on Biofuels from Microalgae
301