biomass to energy conversion

8/2/2019 Biomass to Energy Conversion

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Session 2:Bio-Energy Conversion Technologies (i) agricultural and agro industrialwaste conversion technologies (power, cogeneration and gasification) ;(ii)organic waste conversion technologies (digestion) and (iii) municipal wasteto energy technologies and challenges.


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Source : DTU Denmark


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4

Business Model Technology Resources

IPP Combustion Agro-residue, Plantation,

MSW

Grid-connected tail end

(IPP & RESCO)

Combustion-Rankine Agro-residue, plantation

Gasification-producer

gas/engine

Rice Husk, Shells, pellets

Gasification-biomethanation-

engine/GTG

Habitat wastes, Animalwastes

Off-grid-RESCO Gasification-producer

gas/engine

Rice Husk, Shells, pellets

Gasification-

biomethanation-engine

Habitat wastes, Animal

wastes

Industrial cogen/CHP Combustion/Rankine Industrial wastesGasification-

biomethanation-

engine/GTG

Industrial wastes


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Technology Rationale for promotion

Tail end grid connected

sub 2 MW

Low rural grid penetration

11 KV grid availability

Low per capita rural energy

High load rostering

Low intensity-surplus biomass

Biomass IPP High rural grid penetration

High intensity-surplus biomass

Capacity & fossil fuel constraintsRelatively better performing utilities

Integrated plantation &

biomass IPP

Available degraded forest land, wasteland,

other lands nor suitable for cropping

Favourable State Climate

Small scale CHP SME Industry cluster around biomass rich

areas

Potential food processing industries

Rice mills using per-boil process

Off-grid gasification basedDDG businesses

Grid not accessible/uneconomic to accessAvailability of biomass of appropriate

quality

Efficient cook stoves Community kitchen

Dhabas

Distributed bio-methanation Urban households in tier 1 & 2 cities


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Punjab/ Goa

M.P.Gujarat

BiharMizoram

J&K

Assam

H.P.

Rajasthan

HaryanaKarnataka

A.P.

T.N.

LOWRelative availability of grid power

Penetrationo

fg

rid

Need for network expansion

Need for supplyaugmentation

Uttaranchal

Manipur

IPPs

Tail end

IPP, Tail end

& off-grid

UP


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Biomass Combustion

Fixed Bed Combustion

Underfeed Stokers

Grate Firings

Fluidized Bed

CombustionBubbling Fluidized Bed

Circulating FluidizedBed


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There are a large number of different feedstock types for use ingasifier, each with different characteristics, including size, shape, bulkdensity, moisture content, energy content, chemical composition, ashfusion characteristics, and homogeneity of all these properties.

A wide variety of feedstocks can be gasified: Wood pellets and chips, Waste wood, Plastics and aluminium, Municipal Solid Waste (MSW),

Refuse-derived fuel (RDF), Agricultural and industrial wastes, Sewage sludge, Switch grass, Discarded seed corn, corn stover Other crop residues


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Updraft Downdraft Cross-draft


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Thermal

Incineration

Thermo-Chemical

Pyrolysis

Gasification

Bio- Chemical

AnaerobicDigestion

(Bio-Methanation)

Fermentation

Electro-Chemical

Conversion

MicrobialFuel Cells


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Technology Short Description LimitationsSanitary

Landfilling

Clean & Scientific operation

of landfill sites in order to

reduce pollution

Green waste is not supposed to go the

sanitary landfill

Cost of infrastructure & operating cost is

very high

Incineration MSW with/without

processing/refining is burntto produce electricity or for

heating purposes, thus

reducing 90% of the volume

High moisture content in MSW is a problem

Heating value varies over considerablerange, since segregation is not done

-

Composting Conversion of organic

matter from MSW to

fertilisers

Land requirement for treatment is very high

Additional cost of transportation of end

product is very highBio-

methanation

Bio-degradable waste of

organic or vegetable origin

processed through

anaerobic digestion to

produce a mixture of

methane & carbon dioxide

Segregation of MSW is a must for the option

Project experiences in Pune & Lucknow have

proved to have produce low yield of

methane


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Source ofgeneration

Collection &

logisticsConversionPreparation Power

GenerationRejects

Waste management services are typically divided into a few distinctive functions likeprimary collection, secondary collection, treatment or processing and disposal.Present processing system mainly consists of recovery of recyclable materials andcomposting of the balance for disposalThe key design feature required for the recovery of reasonable quality of fuel is theproper use of a screening operation in the sequence of processing.


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Anaerobic digestion (AD) is a biological process similar in many ways to composting.It is a natural treatment process and, as in composting, bacteria break down organicmatter and reduce its bulk or mass.


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Less energy required Less biological sludge produced Lower nutrient demand Methane production: Providing potential energy source with possible

revenue both from sale of the energy, and benefit from government tax,and (Kyoto agreement) CDM etc. payments arising from renewablefuels/non-fossil fuel incentives

Methane production: Anaerobic digestion contributes to reducinggreenhouse gases by reducing demand for fossil fuels

Smaller reactor volume required

Biomass acclimatisation allows most organic compounds to betransformed Rapid response to substrate addition after long periods without feeding End product can be potentially saleable products biogas, soil conditioner

and a liquid fertiliser. Process more effectively provides sanitisation/removal of diseases.


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Longer start-up time to develop necessary biomass inventory May require alkalinity and/or specific ion addition May require further treatment with an aerobic treatment process

to meet discharge requirements Biological nitrogen and phosphorus removal is not possible Much more sensitive to the adverse effect of lower temperatureson reaction rates May need heating (often by utilisation of process gas) to achieve

adequate reaction rates May be more less stable after toxic shock(eg after upsets due to

toxic substances in the feed) Increased potential for production of odours and corrosive gases. Hazards arise from explosion Anaerobic treatment is not effective for treatment of

methanogenic landfill leachate, it may (rarely) be efficacious forthe early stage leachate production period while the waste is stillacetogenic.


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biomass to energy conversion

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