Biomass Briquetting And

Other Biomass Energy Technologies

Prof. Krishna Raj ShresthaResearch Centre for Applied

Science & Technology Tribuvan University

Primary Energy Sources• Biomass Energy- Any material of plant or animal origin such as

woody biomass (stems, branches, twigs) non-woody biomass (leaves, grass) agricultural residues (rice husk, straw, coconut shell) and animal and human wastes.

• Solar Energy- energy from the sun comes as direct or diffuse radiation.

• Hydro Energy-Utilizes potential energy from water stored behind dams, natural heads (water falls) and kinetic energy of streams or rivers.

• Wind energy- the kinetic energy from the wind is converted by wind turbines into mechanical energy or electrical energy.

• Geothermal energy- heat flow from the earth’s core to the surface by hot water. The heat can be used for space heating , drying or electricity generation.

Primary Energy Sources Contd..• Ocean Energy- includes three energy sources: Wave and tidal,

which both utilize kinetic energy of moving water and Ocean thermal, which utilizes the heat flow between the warm surface waters and cool deep waters of tropical oceans.

• Fossil fuels- Coal, crude oil and natural gas. The main commercial fuels around the world.

• Nuclear Energy- energy released when the nuclei of atoms (usually uranium) break apart. This energy is utilized by converting it into electrical energy.

Introduction to Biomass Conversion Technologies

• The word 'Biomass' is a very comprehensive term comprising of all forms of matter derived from biological activities and are present either on the surface of the soil or at different depths of vast body of water, lakes, streams, river, seas, ocean etc.

Introduction • Biomass refers to all forms of organic matter produced

as products of photosynthesis. Biomass has long served as one of the primary energy forms utilized by human being for essential activities aside from nutrition. Different forms of biomass are

• Forest based products • Timber, fuel wood, wood chips/shavings, saw dust, a

milling residue, forest waste like leaves, twigs, shrubs, herbs herbal products, etc.

• Agriculture based products • Aquatic plants • Animal dung and human waste.

Energy Consumption Situation by fuel type

79.6%

2.8%

3.9%

12.3% 1.2% 0.1%

376.3 MGJ

BiomassGrid electricityCoalPetroleumRenewableOthers

Source :WECS Survey ,2011

43% of the energy used by the third world country is derived from biomass.

2.4 billion people are totally reliant on biomass fuels for their energy needs.

During Photosynthesis, the Sun's energy converts water and carbon dioxide into organic matter.

CO2 +2H2O O2+[CH2O]+H2O

About 3.0X1021 Joules of energy is stored in 2X1011 tonnes of organic matter produced annually by Photosynthesis.

Yet only 14% of the world's energy comes from biomass.

• Cellulose is an organic compound with the formula (C6H10O5)n, a polysaccharide consisting of a linear chain of several hundred to many thousands of β linked D-glucose units.

•   Hemicelluloses are polysaccharides in plant cell walls that have β-(1→4)-linked backbones with an equatorial configuration.

• Lignin is a complex polymer, the chief noncarbohydrate constituent of wood, that binds to cellulose fibers and hardens and strengthens the cell walls of plants.

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• There are basically four major routes for the conversion of biomass to energy and other useful products. These are

• Physical conversion processes• Chemical conversion processes• Bio-chemical conversion processes• Thermo chemical conversion processes

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• Physical Conversion techniques are aimed at physically altering the form of biomass.

• For example,• 1) Physical Conversion Processes:• a) the size reduction of biomass by

chipping, pulverising b) drying to reduce water c) Screening d) densification or briquetting. The main purpose is to prepare biomass suitable for combustion.

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• 2) Chemical Conversion Processes

• Chemical conversion techniques

are aimed at altering the, molecular

structure of biomass. For example, the

acid hydrolysis of cellulose molecules

to glucose followed by fermentation

and distillation.

3) Bio-chemical Conversion Processes

Bio-chemical treatment incorporates the

action of micro-organisms on the biomass for

the production of bio-gas. Examples include

anaerobic digestion, landfilling, composting,

Vermiculture etc.

4) Thermochemical Conversion Processesa) Combustionb) Pyrolysis c) Gasificationd) Liquefaction

a)Combustion: It is the burning of biomass material in the presence of excess quantity of air. It is a chemical reaction of the fuel with the environment including heat and mass transfer.

b) Pyrolysis : It is a physical and chemical

decomposition of organic matter brought

about by heating in the absence of air. The

products of pyrolysis are char, liquid

distillates and gas .

c) Gasification: It is a process in which solid fuels are broken down by the use of heat with a restricted supply of air to produce combustible gases which can be used as a fuel for internal combustion engines. The gas known as producer gas is a mixture of

CO - 15-29% H2 - 5-15% CO2 - 5-15% N2 - 50-65% CH4 - few %

d) Liquefaction: It is a high temp and high-pressure catalytic process ,which converts biomass to fuel oil.

ENERGY SCENARIO IN NEPAL

Total Energy Consumption 376.3 Million GJ (WECS, June, 2014) (1 toe = 41.86GJ)Per Capita energy consumption 15 GJ

Traditional Energy Sources(8.204m toe) 85.0 % Fuel Wood 71.06 %Agri-residues 3.51 %Animal Dung 5.08%

Petroleum 12.28 %Coal 3.93 %Electricity 2.8 %

Renewable 1.22 %

Energy Ladder for Cook Stoves

Biomass Briquetting

Biomass Briquetting is the densification of loose biomass materials (agricultural residues, forestry wastes, animal wastes etc.) to produce compact solid composites of different sizes called briquettes. Densification is the general process of compressing the raw materials to a certain shape or form using a mould and pressure.

Indoor air Pollution 1.9 million people die each year because of indoor air pollution ( The World Health Report, WHO 2006)

Biomass briquettingRequirements for briquetting

• mould and machine (pressure)• biomass raw materials • pressure (P), heat (ToC) and binding agent

Metallic mold/ die

Raw materials of briquetting

Briquette product

Why Briquetting?• Briquetting is applied to improve

•Fuel characteristics •Combustion properties (Combustion

efficiency) •Waste utilization•Easy handling•Minimize wastage•Transportation •Storage

The process of briquetting is applied• to increase bulk density and decrease volume• to ease handling, • to ease transportation, • to manage storage, etc• to improve fuel characteristics – calorific value,

C, Moisture content, AC, VM • to improve combustion properties – T ignition, Period of Ignition, etc• Increase combustion time & slow release of

energy

Biomass briquetting

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Loose biomass & briquettesProperties of loose biomass Briquettes Remarks

Physical properties

Big volume (low bulk density) Low volume/compact (high bulk density)

Packaging is possible

Storage problem Easy to store Indoor storage

Difficult to handle Easy to handle

Difficulty to transport Easy to transport

Fire hazardous Less fire hazards

Limited use Wide use Domestic & Industrial use

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Combustion properties

Fast combustion Slow combustion Easy to tap the heat

Low thermal efficiency Higher thermal efficiency

Smoke generation high Less smoke /no smoke

High emissions of CO,NOx Low emissions Introduction of additives

High moisture (reduction in CV and Ignition temperature)

Low moisture (change in CV & Ignition temperature)

Introduction of additives

Properties of loose biomass Briquettes Remarks

Loose biomass & briquettes

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Types of biomass – Forest waste – saw dust, leaves, twigs. Shrubs,

residues of herbs & herbal products Biomass under high tension linesAgricultural residues -rice husk, rice straw, rice

bran, wheat husk, wheat straw, wheat bran, maize cobs, maize stalks, sugarcane leaves,,

Industrial waste/residues - sugarcane bagasse, coffee husk, tobacco waste, tea waste Herbal residues

Potential Raw Materials• Agricultural Residue - Rice Husk,

Straw of Paddy, Wheat, Maize etc., Pruning of Tea plants, Oil-seed stalks, Legume stalks.

• Forest Residue - Pine Needles, Saw Dust, Banmara, Residue from, Bamboo works,

• Medicinal Plant Residue - Taxus, Pudina, Cintronella, Lemongrass, Asuro, Eucalyptus,

Two Different ways for biomass briquetting

Briquetting CarbonizationBiomass briquettes

Biomass raw materials

Biocoal or charcoal briquettes

Charcoal Powder BriquettingCarbonization

Dire

ct

Different types of Molds,Different parameters of

briquetting – Temperature, Pressure, binders, particle size,

moisture, etc

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Factors effecting briquetting• Temperature - process is easier (ligno-cellulose

materials show elastic properties & increases the flow), moldability is better as materials become soft and the product is better formed when the material is heated

• Pressure - Briquette formation & strength of briquettes is better with increase in pressure (The intra-molecular bond becomes easy due to pressure) (breaking strength)

• Moisture content - An optimum quantity of moisture (enhances binding properties) is necessary for briquetting.

• Size - raw material should be uniform (less then 5 mm in size)

• Hardgrove Grindabilty Index (HGI) – better when HGI is high

• Spring back ratio – better when Spring back ratio is little (dung)

• Ash content – lower ash content of materials is better

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• Size of the briquetting material - The size of the briquetting material both biomass and other briquetting materials should be uniform in size and preferably below 5mm in size. The preferable size is 1-5 mm. Grinding and pulverizing of the material is required if the size is greater. Very fine particles are also not preferable.

• Low moisture content - Moisture content of briquetting material should be as low as possible, generally in the range of 10-15 percent. High moisture content will pose problems in grinding and briquetting. Excessive energy is required for drying. Absolutely dry material also cannot form good briquettes as water sometimes plays the role of a binder.

• Ash content and composition - Biomass residues normally have much lower ash content normally < 5% by weight, (except for rice husk with >15% ash) but their ashes have a higher percentage of alkaline minerals, especially potash. Materials with high ash content are not preferred for briquetting.

Factors effecting briquetting

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Ring matrix pelletizing press Disc matrix pelletizing press

Pelletizer Pellets

Schematic diagram of a piston press

Piston press briquettor Briquettes from Piston press

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Production of Ecofuel

Heating and mixing

Briquetting machine

Cleaning & Pulverizing

Plastic waste

Coal

Drying

Grinding

S and Cl fixation agents N removing agents

Eco-Fuel

Briquetting~1 ton/cm2

compression pressure

Roller press briquetting machine from India

Schematic diagram

Coal briquettes Charcoal briquettes

Roller Press Briquetting technology

Mhepi Briquette Udyog, Nawalparasi

Mhepi Briquette Udhyog (Taiwan machine)

Ganesh Trading Concern

Agglomeration TechnologyCharcoal particles cluster together under the influence of the binder. As the cylinder rotates, the particles are drawn to the top; when they come down again rolling; other particles stick to the agglomerate, which turns into charcoal ball by the “snow ball effect”.

Low Compression Technology

Briquetting Materials Pulping Briquette

Press

Drying Briquettes Briquette stove

Briquetting After Carbonization:Beehive Briquette

Different waste biomass

Lantana camera Mugwort – Tite pati

Banmara Mikania Macrantha - Banmasa

Pine needles

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Carbonization Technologies

The Earth PitTheThe

The Vertical Drum Kiln

Carbonization of Loose residues

Beehive Kiln

Mold with 19 holes

Different Types of Moulds Used in Making Beehive Briquettes

Mold with 17 holes Larger manual mold

Improved hand moldChinese manual mold

Mechanical Mold ( 4molds)

Three molds

Pedal Press

Mechanical Press

Manual/Electrical Pelletizes

Peddle press pelletizer Manual pellet machine Electric pellet machine

Different types of stoves

Improvement of Local innovation for grinding charcoal

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New Briquetting molds - Sajilo Mold

New Sajilo mold with double rodOld mold with one rod

Addition of 2 bolt allows to make half size briquettes

18-Feb-15

Bentonite clay , Potters Clay (no sand no pebbles): 20-30 % by wt

Other binders Starch (Wheat, corn flour, etc) - 10 % Molasses - (5-10%), Pulp black liquor Carboxymethyl cellulose (CMC), 2-3%

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Different Types of binder

18-Feb-15

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New Stoves

Stove for 2 -3 beehive briquettes

New Agni stove – MS plates and

robust

Old Agni stove – GI sheet

Efficiency of stove ~50%

Technical support to Himalayan Naturals

18-Feb-15

k|of]ux?

History of Biobriquetting in Nepal

It is being used since ancient times

Log type above and circular one right

• Since ancient times – use of animal dung briquettes

• 1982 – 1st industry Nepal Bio-Extruder in Thapathali

• 1984/85 - charred RH briquettes research Mohan D Basnet

• 1986 - Demonstration of Rice husk briquetting by Fuji Co with support from Japanese embassy

• ~ 30 industries were registered with DOI• 1987 - Establ of 6 RH briquetting industries

Development efforts in Biobriquetting

• 1989 – research & briquetting of MSW waste by NESS – Branch of Yagai Kagaku, Sapporo

• 1992-1995 - NAST/JICA project– Introduction of Coal BHB & Biocoal, technical help to RHB industries – Tanimec spray welding

• 1995 – Advise to J Sherpa on Roller press briquetting

• 1997 - Introduction of Beehive Briquette from India (Shrestha)

• 1999-2002 - Continuation of Biocoal by IHC-KMTNC – introduction of roller press

• 2000- Introduction of piston press RH briquetting in Birgunj (Lucknow)

Development efforts in Biobriquetting

• 2000-2004 - RETs in ASIA, Biomass briquetting project of AIT-NAST

• Charcoal pellets – CEEN, NAST,CRT/N• Briquetting of MSW and RDF - NAST• 2009 - Technical Cooperation in

Dissemination of Alternative Energy (Biobriquette) Technologies in Nepal –– NEPA-NAST-CEEN

Development efforts in Biobriquetting

Problems and Constraints in Biobriquetting

Problems related with the rice husk briquetting.

High cost of technologyWearing of the screw/worm feeder &

muffHigh cost and seasonal Availability of

the raw material Marketing problems of the rice husk

briquettesBurning/heating devices and ignition

problems Acceptability of the briquettes - slow

burning & smell

Friability of the briquettes and thus difficult packaging and transportation

Quality maintenance

Charcoal making

Grinding and mixing of charcoal

Manufacturing mold

Ignition of briquettes 

Problems Related with Beehive briquetting

Burning Stove

The Agni Stove

Barbecue Stove

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Socio-economy- Cost of different fuels Fuel

Fuel Cost 1990ies

Cost in 2005

Cost 2014

Cost 2016

Fuel wood *Rs 2-4/kg *Rs 6-8/kg

*Rs 10-15/kg

* Rs 20-40/kg

Kerosene Rs 4 liter (Rs 9.5/l-1996)

Rs 26/liter

Rs 103/liter

Rs 75/liter

Rice husk briquette

Rs 5/kg Rs 8-15/kg

Rs 25-30/kg

Rs 30-35/kg

Beehive briquette

NA Rs 15/ Rs 25/pc Rs 30-35/pc

LPG NA Rs 900/cyl**

Rs1470/cyl**

Rs 1400/cyl**

* - only collection cost of wood , ** - LPG in ~15 kg cylinder, but actual is less, subsidized Effectiveness of different fuels Fuel

N Energy Type Unit quantity

Price (Rs/unit Q)

GJ/Unit Q

GJ/Rs

Efficiency (%)

Effective

GJ/Rs1 Fuel wood 1kg 4.42 0.0167 0.00

3817 0.0006

2 Electricity Kwh 4.00 0.0036 0.0009

76 0.0007

3 Gas 1 kg 21.13 0.0452 0.0021

70 0.0015

4 Kerosene 1liter 9.00 0.0365 0.0041

48 0.0020

5 RH Briquette 1 kg 3.40 0.0223 0.0065

37 0.0024

6 Beehive briquette*

1pc (~350gm

)

30.00 NA NA 45** NA

N.B.* Beehive briquette–current market (2016) price, ** value from RETS test (2015) in Agni stove

Source: WECS 1995

The beehive briquetting technology is simple, pollution free and

eco-friendly. It provides smokeless domestic fuel easily ignitable

with sustained uniform combustion. The use of agro-forestry

residues can replace fuel wood and wood charcoal. Being eco-

friendly with high social relevance and having the potential to

contribute forest conservation, this technology should be widely

promoted throughout Nepal.

CONCLUSION

THANK YOU

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Low Cost Can Stove for RH Briquettes and Charcoal Pellets

18-Feb-15

86

Belonio Stove using Granular Biomass

18-Feb-15

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Institutional Stove with Blower using RH Briquettes

18-Feb-15