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27 Bioconversion of Waste to Wealth as Circular Bioeconomy Approach

Anaerobic digestion (AD) systems convert organic wastes to methane (CH4) and

carbon dioxide CO2 by utilizing the acid-forming and methane-forming bacterial

biomass. Comparisons of phase one and two anaerobic diets based on methane and

hydrogen recovery showed two-phase approach to achieve a complete hydrogen

output and a 20% higher energy gain because of increased methane production as

compared to hydrogen-related production [13]. Studies on life cycle assessment

performed to determine the environmental impacts of replacing traditional diges-

tive feedstocks with anaerobic show that these replacements reduce gas pollution,

can control the loss of nutrients in water sources, and can reduce the effects of

eutrophication [14].

The use of organic wastes for biofuels production was studied as an alternate

approach to using fossil fuels. Some of the key barriers identified include high

production costs and high energy consumption. The report also suggests a novel

idea to improve biodiesel production from waste oil using a combined reactor [15].

The current trends in research are focused on improving the sustainability and

economic feasibility of the concept of consolidated bioprocessing and on the fourth

generation [16].

27.3

Bioeconomy Waste Production and Management

Reuse includes the segregation, classification, promotion, and repair of discarded

material from a solid waste stream. Today the modification, remanufacture, and

recycling of these items to be used as a product feedstock for brand new items are

gaining much popularity. Circular economy (CE) is achieved through the 3R system

(Resources, Recycling, and Recovery), which leads to use of sustainable resources

and eventually leading to enhanced economic development. CE has recently gained

much attention from the industrial economy through the loop economy, with a focus

on measures such as waste prevention, resource efficiency, and job creation [17, 18].

Municipal solid waste (MSW) has great potential toward renewable energy genera-

tion, by linking concepts of waste management and recycling [19].

The recycling practice is executed in residential, commercial, and industrial

markets. The streams of MSW found in these locations can be classified as:

1. Residential solid waste: solid waste produced from either single or multifamily

living arrangements. The recyclables that are prevalent in this stream include

paper, plastics, metals, food scraps, and individual hardware.

2. Commercial

strong

waste:

strong

waste

generated

by

organizations,

workplaces, stores, markets, organizations, government, and other busi-

ness institutions. Some of the wastes with potential recyclability include paper,

plastic, metals, food, yard trimmings, wood, materials, and electronic gadgets.

3. Industrial strong waste: strong waste created from non-process lines, deliver-

ing, and plant workplaces.

The biorefinery concept could become an important part of the development of

a circular economy. Integration of multidisciplinary approaches to biomass/waste