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20 Application of Sustainable Micro-Algal Species in the Production of Bioenergy

Development of green growth includes the reaping process and shielding the

development framework from the sullying of wild green growth. They may bring

about expanded creation costs, anyway, the lignocellulosic bioethanol process

additionally has the issues of exorbitant and vitality escalated pretreatment process

just as costly protein used for the hydrolysis of lignocellulosic materials [12].

The procedure financial matters can be improved impressively using the algal

buildup through biorefinery innovation along with the creation of numerous green

growth-based items using biorefinery that forms green growth biofuel. It can be

monetarily serious to lignocellulosic bioethanol.

Life cycle assessment (LCA)) has become critical in assessing the natural effects

brought about by the procedure and the enhancing of the stage change from biomass

to biofuel. The net vitality utilization is shifted relying upon the development tech-

nique. It shows development by reusing carbon for CO2 obsession. Similar vitality

LCA is decided through a variety of development framework (open framework and

shut framework) and sort of reactors that utilized the estimation of net vitality pro-

portion (NER) > 1. This emphasizes a point that the vitality of microbial biomass

created by OP is higher than the vitality devoured by the framework. Operation is

found to have lower ozone harming substance emanation than PBR, since a piece of

the green growth biomass may experience anaerobic absorption.

20.2.7

Large-Scale Production and Processing of Microalgae

Microalgae are cultivated for producing renewable bioenergy. There are various

routes of bioenergy production from microalgae that are presently available. They

also have properties which makes them the appropriate sources of eco-friendly

fuels [13]. The oil is first extracted from the algae using a series of techniques like

using simple oil expeller, microwave-assisted, ultrasonication-assisted, supercritical

extraction, wet extraction, etc. The oil is then converted to biofuel using different

processes.

20.2.7.1

Biomethane Production by Anaerobic Digestion

Anaerobic digestion (AD) process converts microalgae into biofuel. It is a biochem-

ical process that converts organic compounds into biogas, also methane through

the synergistic action of microorganisms under anaerobic conditions. Biogas is com-

posed of methane (around 50–70%), CO2, fractional amounts of ammonia, H2S, and

volatile organic compounds. AD is a mature technology that treats organic waste

streams. Owing to its simple usage and environmental benefits, it is widely practiced.

It is suitable for both dry and wet organic feedstocks. In the case of wet feedstocks,

it has to be dewatered before processing. The process does not require any pretreat-

ment. AD has high economic and environmental benefits, since the process effluents

are captured for the repeated use of carbon dioxide, phosphorus, and ammonia. The

following are the steps involved in the AD process:

●Hydrolysis: the breakdown of macromolecules such as carbohydrates and lipids

into sugars, amino acids, and fatty acids.