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31 Critical Issues That Can Underpin the Drive for Sustainable Anaerobic Biorefinery

Environmental

benefits

Energy benefits

Biogas production

Social benefits

Agricultural benefits

Effluent quality

Substrate

characteristics

Digester

Design and

operating conditions

Public health

benefits

Policies promoting anaerobic

digestion of waste

Figure 31.7

Multi-beneficial system context of the AD.

transition, in close cooperation with the gas sector [57]. The potential for technolog-

ical improvements on the economic horizon is so significant and so comprehensive

that it could redefine the biogas industry and help foster the integration of green

power into the national energy system.

AD technology has been commercially demonstrated within Europe and is

a crucial factor for European development as biogas provides the potency for

sustainable bioenergy production. However, biogas economy is related to several

technical factors such as waste availability, AD efficiency (digester performance),

and end-product properties [58]. Interrelationships between the two major perfor-

mance influencers of an anaerobic digester, design and operating conditions and

substrate characteristics, and their influence on the effluent quality and biogas

production induce various benefits in the fields of agriculture, energy, environment,

public health, social, and political, which are depicted in Figure 31.7.

There is also a wide variety of biowaste with low cost and high availability that

can be converted into biogas. The scenario of biogas production from biowaste types

can save space for composting waste and provide clean energy, thus mitigating GHG

emissions and waste. Substrate properties are important for the digester type selec-

tion, the quality and quantity of the biogas yield, and hence the project costs [59].

However, biogas-based engines are not yet developed enough to deal with the

technical issues of biogas use. Aside, the nontechnical barriers vary significantly

across each country. Poor or directly restrictive national legislative framework, not

suitable to support the implementation and operation of biogas projects, lack of eco-

nomic incentives (such as higher electricity tariffs, tax exemptions, etc.) hinder the

development of biogas projects [60]. A transversal approach for policy integration

is recommended to ensure that all relevant concerns are considered. European pol-

icy aims to trigger the incentives of the member countries on the direction of green

mobility by establishing criteria for sustainable gaseous biofuels, such as the feed-in

tariffs in Germany, the obligation certification for energy renewability in the United

Kingdom, and the tax policy in Sweden [61].