16.1 Introduction

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Organic solid waste

Cooking

Heating

Electricity

Application

Efficient (bio-fertilizer)

AD bioreactor

Upgrading devices

Biogas

Bio-methane

Application

Transport

fuel

Nagural gas

substitute

Figure 16.2

Biogas production and the potential applications.

from acetic acid and the reaction between H2 and CO2 with the latter being more

common [6, 7]. The chemical composition of raw biogas from a typical solid waste

AD facility is dependent on the process environment. Typically, it contains 50–75%

CH4, 30–50% CO2, 0–3% N2, ∼6% H2O, 0–1% O2, 72–7200 ppm H2S, 72–144 ppm

NH3, and other minor impurities [8, 9]. The raw biogas can be straight applied for

making electricity and heat while upgraded gas (biomethane) can be inserted into

the natural gas grid or used as vehicle fuel (Figure 16.2). Gas purifying in the early

stage will exclude impurities that could spoil mechanical and electrical appliances

during the use of biogas and can be accomplished by adsorbing with silica gel

and activated carbon or molecular sieves. Superior techniques are used mostly for

escape of CO2 from CH4 to rise the calorific value of the gas. These techniques are

water scrubbing, pressure rollback adsorption, cryogenic technology, membrane

separation, and organic scrubbing using amines such as diethanol amine, di-glycol

amine, and mono-ethanol amine.

16.1.2

Biohydrogen Production

Biohydrogen manufacturing is a very smart option as an unconventional energy

supply and most striking energy vector for the future. In recent times, range of

biohydrogen-manufacturing pathways has been recommended to get better the

main features of the practice. Nonetheless, researches are still required to conquer

the residual hurdle to rational appliance such as small yields and manufacturing