BTE 4216

BIOMASS ENERGY

FAST PYROLYSIS OF COW DUNG FOR ENERGY

PRODUCTION

MUHAMMAD AIMAN BIN MOHD ZIN (0721471)

MOHD RAZI BIN KODIN (0714313)

ISMAIL TOPA (0713105)

MOHAMMAD ZAID BIN MOHAMMAD ZAINI (0637425)

MAHER MOHAMMED ALI (0612081)

PYROLYSIS OF COW FOR ENERGY PRODUCTION 1

Contents

Contents 1

Introduction 2

Electricity generationBiomass: New alternative source of energy 4

Case study: Electricity from cow dunk 11

Cost estimation 17

Conclusion 19

PYROLYSIS OF COW FOR ENERGY PRODUCTION 2

1.0 Introduction

As biomass is a natural material, many highly efficient biochemical processes have

developed in nature to break down the molecules of which biomass is composed, and many of

these biochemical conversion processes can be harnessed.

Pyrolysis is the process of heating biomass in low-oxygen, which does not burn the

biomass in a combustion reaction, but instead causes the biomass to release energy-rich gases,

and leave a remainder of "biochar". The gas released in the pyrolysis process is called "producer

gas". It is a mixture of combustible gases that can be used (via combustion) to drive the

continued heating of the pyrolysis process, and can be used to generate electricity. Current

technology uses combustion of producer gas in turbines to generate electricity. Emerging

technologies can feed producer gas into fuel cells, thus generating electricity without

combustion.

Pyrolysis also produces pyrolysis oil, or "pyroil", which condenses out and separates

from the producer gas, which remains in gaseous form. Pyroil is an energy rich biofuel which

can be burned as heating oil, and can potentially be refined to higher-grade biofuel forms.

Biochar is the carbon-rich remainder of the biomass. It has some energy value, and could

be used for energy production in, for example, co-firing with coal. Biochar also has value as a

soil amendment, and it does not tend to break down and release CO2 over time, so it serves the

function of carbon sequestration.

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Agricultural activities produce large quantities of animal wastes in the form of manures.

While some of the manure can be used as fertilizer, not all of it can be consumed in this way and

the excess is an environmental liability. Another possibility is to use the manure as a direct or

indirect source of fuel for remote power generation. The use of animal manure for fuel has

several benefits.

1.1 Fast Pyrolysis

Fast pyrolysis for liquids production is of particular interest currently. Fast pyrolysis

occurs in a time of few seconds or less. Therefore, not only chemical re action kinetics but also

heat and mass transfer processes, as well as phase transition phenomena, play important roles.

The critical is sure is to bring the reacting biomass particle to the optimum process temperature

and minimize its exposure to the intermediate (lower) temperatures that favour formation of char

coal. One way this objective can be achieved is by using small particles, for example in the

fluidised bed processes that are described later. Another possibility is to transfer heat very fast

only to the particle surface that contacts the heat source. This second method is applied in

ablative processes that are described later.

In order to illustrate the science and technology of thermal conversion in sufficient detail

to appreciate the potential, fast pyrolysis is described at length. The use of pyrolysis process to

produce medium Btu fuel gases (350 – 550 Btu/ft3) for remote biomass power generation was

investigated. This approach has several advantages when compared to more conventional

processes.

PYROLYSIS OF COW FOR ENERGY PRODUCTION 4

Hence, our mini project will concentrate on how to generate electricity using cow dung as

source of biomass by fast pyrolysis means. Throughout this project we will design and estimate

the amount of source needed to generate 5000 MWh electricity using pyrolysis technique.

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2.0 Electricity generation

Electricity generation is the process of generating electricity from other forms of energy.

The fundamental principles of electricity generation were discovered during the 1820s and early

1830s by the British scientist Michael Faraday. His basic method is still used today: electricity is

generated by the movement of a loop of wire, or disc of copper between the poles of a

magnet.For electric utilities, it is the first process in the delivery of electricity to consumers. The

other processes, electricity transmission, distribution, and electrical power storage and recovery

using pumped storage methods are normally carried out by the electrical power industry.

Electricity is most often generated at a power station by electromechanical generators,

primarily driven by heat engines fueled by chemical combustion or nuclear fission but also by

other means such as the kinetic energy of flowing water and wind. There are many other

technologies that can be and are used to generate electricity such as solar photovoltaic and

geothermal power.

2.1 Methods of generating electricity

There are seven fundamental methods of directly transforming other forms of energy into

electrical energy:

1) Static electricity, from the physical separation and transport of charge (examples:

turboelectric effect and lightning)

2) Electromagnetic induction, where an electrical generator, dynamo or alternator

transforms kinetic energy (energy of motion) into electricity

PYROLYSIS OF COW FOR ENERGY PRODUCTION 6

3) Electrochemistry, the direct transformation of chemical energy into electricity, as

in a battery, fuel cell or nerve impulse

4) Photoelectric effect, the transformation of light into electrical energy, as in solar

cells

5) Thermoelectric effect, direct conversion of temperature differences to electricity,

as in thermocouples, thermopiles, and Thermionic converters.

6) Piezoelectric effect, from the mechanical strain of electrically anisotropic

molecules or crystals

7) Nuclear transformation, the creation and acceleration of charged particles

(examples: betavoltaic or alpha particle emission)

Static electricity was the first form discovered and investigated, and the electrostatic

generator is still used even in modern devices such as the Van de Graaff generator and MHD

generators. Electrons are mechanically separated and transported to increase their electric

potential. Almost all commercial electrical generation is done using electromagnetic induction,

in which mechanical energy forces an electrical generator to rotate. There are many different

methods of developing the mechanical energy, including heat engines, hydro, wind and tidal

power.

The direct conversion of nuclear energy to electricity by beta decay is used only on a small

scale. In a full-size nuclear power plant, the heat of a nuclear reaction is used to run a heat

engine. This drives a generator, which converts mechanical energy into electricity by magnetic

induction.

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Most electric generation is driven by heat engines. The combustion of fossil fuels

supplies most of the heat to these engines, with a significant fraction from nuclear fission and

some from renewable sources.

3.0 Biomass: New alternative source of energy

Biomass, a renewable energy source, is biological material from living, or recently living

organisms, such as wood, waste, (hydrogen) gas, and alcohol fuels. Biomass is commonly plant

matter grown to generate electricity or produce heat. In this sense, living biomass can also be

included, as plants can also generate electricity while still alive. The most conventional way in

which biomass is used however still relies on direct incineration. Forest residues for example

(such as dead trees, branches and tree stumps), yard clippings, wood chips and garbage are often

used for this. However, biomass also includes plant or animal matter used for production of

fibers or chemicals. Biomass may also include biodegradable wastes that can be burnt as fuel. It

excludes such organic materials as fossil fuels, which have been transformed by geological

processes into substances such as coal or petroleum.

Industrial biomass can be grown from numerous types of plants, including miscanthus,

switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, and a variety of tree species,

ranging from eucalyptus to oil palm (palm oil). The particular plant used is usually not important

to the end products, but it does affect the processing of the raw material.

3.1 Chemical composition

Biomass is carbon, hydrogen and oxygen based. Nitrogen and small quantities of other

atoms, including alkali, alkaline earth and heavy metals can be found as well. Metals are often

PYROLYSIS OF COW FOR ENERGY PRODUCTION 8

found in functional molecules such as the porphyrins which include chlorophyll which contains

magnesium.

Plants in particular combine water and carbon dioxide to sugar building blocks. The

required energy is produced from light via photosynthesis based on chlorophyll. On average,

between 0.1 and 1 % of the available light is stored as chemical energy in plants. The sugar

building blocks are the starting point for the major fractions found in all terrestrial plants, lignin,

hemicellulose and cellulose

3.2 Biomass sources

Biomass energy is derived from five distinct energy sources: garbage, wood, waste,

landfill gases, and alcohol fuels. Wood energy is derived both from direct use of harvested wood

as a fuel and from wood waste streams. The largest source of energy from wood is pulping liquor

or “black liquor,” a waste product from processes of the pulp, paper and paperboard industry.

Waste energy is the second-largest source of biomass energy. The main contributors of waste

energy are municipal solid waste (MSW), manufacturing waste, and landfill gas. Biomass

alcohol fuel, or ethanol, is derived primarily from sugarcane and corn. It can be used directly as a

fuel or as an additive to gasoline.

Biomass can be converted to other usable forms of energy like methane gas or

transportation fuels like ethanol and biodiesel. Rotting garbage, and agricultural and human

waste, release methane gas - also called "landfill gas" or "biogas." Crops like corn and sugar

cane can be fermented to produce the transportation fuel, ethanol. Biodiesel, another

PYROLYSIS OF COW FOR ENERGY PRODUCTION 9

transportation fuel, can be produced from left-over food products like vegetable oils and animal

fats. Also, Biomass to liquids (BTLs) and cellulosic ethanol are still under research.

4.0 Case study: Electricity from cow dunk

In 2001, Malaysia has about 723 400 cows in various farm across country. The use of cow

dung as a source of electricity is still rare. Most of the application of cow dung is as a fertilizer.

4.1 Reactor design

4.1.1 Process from cow dung to methane gas

COW DUNG COLLECTION POND

Pyrolysis

anhydrocellulose

β-glocusan

dehyrationeChar, tar, CO, CO2, H2O

Char

Combustible volatiles

depolymerization

PYROLYSIS OF COW FOR ENERGY PRODUCTION 10

4.1.2 Products of pyrolysis from cow dung

The pyrolysis process of cow dong is possible due to the nature of it. It has very high

composition of carbon source. The following table shows the analysis of the elements present in

cow dung.

Basis Moisture Ash C H O S N

Ash free 24.5 - - - - - -

Dry - 74.0 13.2 1.8 8.5 0.6 1.9

Dry Ash Free - - 50.5 7.1 32.8 2.3 7.3

The dung goes under flash pyrolysis producing up to 90% combustible gases. When the process

is finish, other form of solid would be found in small amount about 10%.The emission of the

gases in the primary pyrolysis is collected; the contents are summarized as the following tables.

The first table shows the categories of the gas compositions.The second table shows the

composition in more details.

PYROLYSIS OF COW FOR ENERGY PRODUCTION 11

The flash pyrolysis uses a very rapid residence time (fraction of a second) and very high

temperature (1000-3000ºC). Thus resulting in gases as the primary products. The data shows the

contents of solid is only 9.06% represents as tar. For the purposes of generating energy, we

conseider only two of the produced gases; CH4 and C2H5. The reason is that they are combusted

into CO2 andH2O and not leaving harmful emotions as Acetaldehyde or Acetone.

CH4 produced per 1 kg dung = 0.74% × 100 = 0.0074kg

C2H5 produced per 1 kg dung = 0.13% × 100 = 0.0013kg

Component Freewt.%Tars 9.06CH4 0.74H2O 19.93CO2 24.87CO 15.64C2H4 0.13SO2 0.49COS 0.58NH3 0.93HCN 1.46Formic Acid 0Acetic Acid 0.5CH3OH 0.47Formaldehyde 0.54Acetaldehyde 2.57Acetone 0.72HNCO 0.86

NO 1.42

Component Freewt.%

Moisture 26

Ash 52.7

VolatileMatter 17.2

FixedCarbon 4

PYROLYSIS OF COW FOR ENERGY PRODUCTION 12

4.1.3 Energy from the gases

The two main gases in our pyrolysis would be used to produce electricity. We are here to find the

energy given by combustion of these two gases. The energy is the heat of reaction.

For Methane:

CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) ∆G = -891 kJ/mol

The energy released = 891kJ/mol × 1mol/12g = 74.25 kJ/g × 1000g/kg =

74,250 kJ/kg

The energy released per 1 kg dung = 74,250 kJ/kg × 0.0074 kg = 519.75 kJ

519.75 kJ / 3600 kWh/kJ = 0.144375kWh per 1 kg dung

For Ethylene:

C2H4(g) + 3O2(g) → 2 CO2 (g) + 2 H2O(l) ∆G = -1409.5kJ/mol

The energy released = 1409.5kJ/mol × 1mol/12g

=117.458333kJ/g×1000g/kg = 117,458.33kJ/kg

The energy released per 1 kg dung = 117,458.33kJ/kg × 0.0013 = 152.7 kJ

152.7 kJ / 3600 kWh/kJ = 0.0424166667kWh per 1 kg dung

The total sum of energy produced by 1 kg of cow dung is = 0.144 + 0.042 =

0.186kWh

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4.2 Energy production

After the pyrolysis processes, the product are collected. In our case the products are

methane and ethy1ene. The heat released by combustion of those gases in 1kg of dung produces

0.186kWh.

These gases have very high combustion value with an efficiency of 78% of the heat converted to

electricity in the plant generator.

To produce 5000MWh of electricity;

5000MWh = 5 000 000 kWh

The energy of heat of reaction has to be = 5,000,000 kWh/0.78 = 6,410,256.41 kWh

The amount of dung needed for 5000MWh electricity = 6,410,256.41/0.186

= 34,463,744.1kg of dung

= 34,463.74tons of cow dung

1 cow produces 0.065 tons of dung per day, in a year = 0.065 × 365 = 23.72 tons

Total cow for the dung required per day to give 5000MWh electricity =

(34,463.74)* (0.065)= 224,014.31head of cows

In 2001, Malaysia has 723,400 cows across country. Assuming a proper collection of cow

dung is performed and only a single power plant is use. The amount required for 5000MWh

electricity is34,463.74 tons. It is reasonable to be collected and sent one plant since we need only

224,015 cows from 723,400 across the country.

PYROLYSIS OF COW FOR ENERGY PRODUCTION 15

5.0 Economic analysis

A. Raw materials

34,463.74 tons of cow dung

RM 20 per ton = RM 20 × 34,463.74 = RM 689,274.8

= RM 689,274.8

B. Chemicals

The fuel for the combustion process = RM10,000

= RM10,000

C. Facility construction

Assuming in Pahang

I. Land:

RM 16,550 per acre (×10) = RM 165,500

= RM 165,500

II. Pyrolysis facility:

Bubbling Fluid Bed Reactor @ Dyna Motive (Vancouver,Canada) for 1000t/d (× 34)

= RM 10m × 34 = RM 340,000,000

Hot Vapour Filtration @ NREL & VTT

=RM 20k × 17 = RM 340,000

Operating cost of the pyrolysis process = RM 1,000,000 annually

=RM 341,340,000

PYROLYSIS OF COW FOR ENERGY PRODUCTION 16

III. Electricity plant:

Generator RM 1 million (×4) = RM 4,000,000

= RM 4,000,000

IV. Storages and utilities:

Tanks (for dungs) RM 100,000

Tanks (Gas) RM 465,000

Separation Station RM 50,000,000

Pumping Station RM 85,000

Buildings and warehouse RM 5,600,000

Pipings RM 1 ,000,000

Water and Electricity RM 670,000

Maintainace RM 2,500,000

= RM 60,420,000

D. Transportation:

25 Lorries RM 3,500,000

Fuels and tolls RM 70,000

= RM 3,570,000

PYROLYSIS OF COW FOR ENERGY PRODUCTION 17

E. Labors:

250 workers × RM 2000 per Month × 12 Month = RM 6,000,000

= RM 6,000,000

F. Emergency & other costs:

RM 50,000 per month x12 month = RM 600,000

Total cost 1st year= RM 416,194,774.80

2nd year= 1st year – Fixed cost = RM 416,194,774.80 – RM 405,225,500 = RM 10,969,274.8

Revenue = 5,000,000 KWh× RM 0.23 per KWh = RM 1,150,000 per day

Revenue per year = 1,150,000 × 365 = RM 419,750,000

Profit 1st year = RM 419,750,000 - RM 416,194,774.80 = RM 3,555,225.20

Profit 2nd year = RM 419,750,000 - RM 10,969,274.8 = RM 408,780,725.20

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6.0 Conclusion

As discussed in this project, we could conclude that biomass energy is a better alternative

to generate energy and income. Specifically, cow dung that can really build a more feasible

economical project and it keep a clean environment.

Hence, our mini project studied the ways and methods of generating electricity using cow

dung as source of biomass. In the project we have designed and estimated the amount of source

needed to generate 5000 MWh electricity using biochemical conversion. Besides, we also

propose a power plant suitable to generate electricity using cow dung. The economical studies in

terms of costs and profits were also discussed.

To sum up with, We could propose using cow dung as source of energy that can be a very

feasible and viable economical project as well.

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7.0 Reference

http://www.theepochtimes.com/n2/content/view/1604

http://www.oardc.ohio-state.edu/

http://helenchangwriter.com/2010/11/14/creating-electricity-from-cow-dung-and-old-

frying-oil/