INTRODUCTION

A major part of human lifestyle and comfort is totally depends on the energy consumption such
as electricity, transport etc. The basic conventional sources behind this energy production are
fossil fuels. We all know that fossil fuels are non renewable and depleting day by day. The
increasing prices of the fuels are also a point of issue. For tackling these all issues the alternate
sources are found to make a constant flow of energy without affecting the environment. An
increase in global awareness about environment issues pushing us towards the use of alternative
fuels. There are lot of research work is done globally on alternate renewable sources. Alternate
energy comprises all those things that don’t use of fossil fuels. These are widely available and
eco-friendly.

Biomass energy or energy from burning from burning the plants and other organic material is
one of the human’s earliest sources. Now a days biomass energy is a developing type of energy
for various applications. They may be used for energy production at different scales including
large scale power generation, CHPs, or small scale thermal heating projects. The main advantage
of developing this type of energy is that it is abundant on earth, make from waste and
environment friendly. In our project we are using sugarcane bagasse as woody biomass. The
production of gas is done by down- draft gasifier. The producer gas is implementing to the duel
fuel single cylinder diesel engine and we are studying the performance characteristics results.

Definition of Biomass

It is biodegradable material (but not a fossil fuel) which is derived from the waste of
environmental organisms. Biomass comes from both human and natural activities and crops,
forestry residues, household waste and wood. The canola oils to animal fats, from prairie grasses
to hardwoods and includes algae.

Biomass power is the largest source of renewable energy as well as vital part of waste
management infrastructure. Woody biomass is the most important renewable energy source if
proper management of vegetation is ensured. Due to these special characteristics it is globally
acceptable and recently in the developing stage.

News in Biomass energy

In India, the energy production through biomass is quite unsatisfactory. Technologies are not
developed to improve the use of biomass under different application. On the other hand United
States is currently largest producer of electricity from biomass having more than half world’s
population installed capacity. More than 7800 MW of power is produced in biomass power
plants installed more than 350 locations in the US, which represent 1% of the total electricity
generation capacity. According to the International Energy Agency, the approximately 11% of
the energy is derived from biomass throughout the world [7].

Basic knowledge of biomass as a fuel

Biomass is an organic waste matter derived from living organisms, generally plant based
materials. Although termed as organic waste matter yet it is used as source of energy for the
reason that the biomass energy has the potential to greatly reduce greenhouse gas emissions.
These include food crops, grassy and woody plants, residues from agriculture or forestry, oil-rich
algae, and the organic component of municipal and industrial wastes. Even the fumes from
landfills (which are methane, the main component in natural gas) can be used as a biomass
energy source. Conversion of biomass to bio-fuel can be achieved by different methods which
are broadly classified into: thermal, chemical, and biochemical methods.

Wood remains the largest biomass energy source today. Woody biomass is one important
category of biomass often used to refer to any non merchantable wood materials that do not have
an existing local market. This could include live trees, forest, and manufacturing residues or
consumer waste materials.

Sugarcane Bagasse: The source of energy used in this project is sugarcane bagasse. It is one of
these lignocellulose biomass. It is the fibrous residue left after the extraction of juice from
sugarcane stalks. It is utilized as a bio-fuel and in the manufacture of pulp and building material.
It is considered as an effective biomass residue for the production

The properties important for a biomass to be used as fuel are

 Moisture content
 Calorific value
 Proportions of fixed carbon and volatiles
 Ash/residue content
 Alkali metal content
 Cellulose/lignin ratio
Biomass with high moisture content results in a wet/aqueous conversion process like the
fermentation while a dry biomass is suited to gasification, pyrolysis or combustion. Aqueous
processes are used when the drying or pre-processing of the biomass is not economic considering
the energy input and output in the whole process.

Different types of energy conversion processes for the production of gaseous fuel

Conversion of biomass to energy is undertaken using three main process technologies. They are
classified as:

 Thermo-chemical
 Combustion
 Gasification
 Pyrolysis
 Bio-chemical/biological
 Fermentation
 Anaerobic digestion
 Mechanical Extraction

Block diagram of Biomass conversion (encircled with our using process)

Gasification

It is a thermo-chemical process that breaks down virtually any carbon-containing material into its
basic chemical constituents, collectively known as synthetic gas (syn- gas). This process consists
of a number of physical and chemical processes including rate-determining steps, and takes place
under limited supply of O2 so that partial oxidation can increase the efficiency of the entire
process.
These are various types of gasifiers,

 Updraft
 Downdraft
 Crossdraft
 Fluidised Bed
 Entrained Flow
 Plasma

Out of these various types of gasifiers, the fixed bed type gasifier is the most commonly used.
And in our experiment we are also going to perform our experiments using a downdraft gasifier
which is a type of fixed bed type gasifier. Synthesis of syn-gas using a downdraft gasifier
involves following processes & each of them are having their own temperature range

1. Drying (<120°C)
2. Pyrolysis (200°C - 800°C)
3. Oxidation (800°C - 1100°C)
4. Reduction (1100°C - 600°C)

Heat & Mass flow in gasification process

Downdraft Gasifier

The downdraft gasifier is referred mostly than the other types because the other types of gasifiers
experience a problem of tar entrainment which is solved in this type of gasifier by introducing a
gasifying agent above the oxidation zone of the gasifier. This type of gasifier is similar to up-
draft gasifier, except for that the zones mentioned in the diagram are located in the reverse order
where pyrolysis products pass through the high temperature oxidation zone and undergo further
decomposition into combustion products.

Stage process in a downdraft gasifier

Dehydration, as a consequence of moisture evaporation occurs in the drying zone of the gasifier,
and the evaporated moisture serves as a reaction agent during gasification. The product gas exits
from the bottom of the gasifier, and contains significantly less amount of tar, compared to the up
draft gasifier with high quantities of tar in the product gas. As a result of this the need of gas
cleaning reduces, and therefore leaves the gas suitable for a wide variety of applications.
Depending on the temperature of the oxidation zone, tar and Pyrolysis products from the feed
pass through a glowing bed of charcoal and a reconverted into a gas containing CO, H 2 and CO2,
CH4.

The major advantages of the down draft gasifier stem from its low tar production rate(most of the
tar produced is disintegrated in the high-temperature oxidation zone of the gasifier, low
entrainment of particulate matter, low capital, operational cost and its simplicity and ease of
operation. The down draft gasifier design has simple and easy control systems when compared to
other types of gasifiers. The wear rate of the down draft gasifier is minimal; as a result, the
maintenance cost is low. Its major disadvantage lies in its difficulty to handle feed with high
moisture and ash contents, and its inability to operate on a number of unprocessed fuels. Lack of
internal heat exchange and lower heating value of the product gas from a down draft gasifier are
also some of the minor drawbacks of the system when compared with the updraft system. As
with most gasification systems, another major drawback of the down draft gasifier is the inability
of scale-up. The down draft gasifier cannot be developed on a large scale (maximum thermal and
power outputs are approximately 1300kWth and 400kVA respectively) due to non-uniform heat
distribution within its oxidation zone, which also has been attributed to its design characteristics,
however the time required to ignite and bring the plant to a working temperature is
approximately 20 – 30 min, which is quite shorter than that required for the updraft gasifier.

Dual Fuels

As time progresses, efforts have been put forward to decrease the amount of fuel consumed by
the engines, in order to make them more efficient as well as economic as the rate of fossil fuel
depletion keeps incrementing day by day. The diesel engines were found to be perfect for this
job as they are able to operate well with two fuels, one of which is the conventional liquid fuel
(diesel) that constitutes 5-7% of the whole charge and the other, the gaseous fuel that makes up
the rest of the charge.

According to the Britannica Encyclopedia, it all began on August 10, 1893 at Augsburg, when
Rudolph Diesel ran the prime model of his engine for the first time. The first run did not turn out
to be successful as the engine ran for a while and after which the indicator plate exploded. This
motivated Diesel to make improvements in his model, which took him three more years, to
finally make his invention work. On the last day of year 1896 he demonstrated the improved
model of his engine whose theoretical efficiency turned out to be 75.6%, about 10% greater than
the steam engines employed in those days for power generation. The commercial manufacturing
of his engine began a year later. On April 30, 1901 the patents of the dual fuel and the gas diesel
engines were issued to Rudolph Diesel by the U.S Patent Office.

The dual fuel engine provides an advantage over the standard spark ignition engines by being
able to operate on both liquid and gaseous fuels. The engine also possesses the ability to switch
over from the dual fuel mode to full diesel mode whenever needed.

The operation of the dual fuel engine differs from the standard compression ignition engine only
in the procedure of charge induction, for which the engine has been improved mechanically. The
induction process initiated with the induction of the primary (gaseous) fuel and coalescing it with
the air in the inlet manifold. This mixture is compressed to the respective pressure that the engine
is configured to work at. At this point a small amount of pilot (liquid fuel, diesel) is injected,
which helps to initiate combustion, which further leads to the execution of the power stroke. Rest
of the cycle comprises of identical operations of a conventional compression ignition engine.

At present the dual fuel technology is being mostly incorporated in the field of 4 wheeler
vehicles, some of which are:-
  Fiat Siena Tetra fuel, using gasoline flex fuel engine and natural gas (CNG)
 Holden Commodore using petrol and LPG
 Volkswagen Polo using petrol and LPG
 Chevrolet Cavalier
 Dacia Duster
 Ford F-250

LITERATUTRE REVIEW
Chandrakanta Nayak et al. [1] have studied on twin cylinder dual fuel diesel engine for
maximum diesel savings and lower emissions without undue vibration of engine using woody
biomass producer gas. They used babul wood (Prosopis juliflora) as a woody biomass.

They have discussed their results that the engine performance decreases in a dual engine mode at
all test. Certain things improved such as BSFC is found to be 15.71% higher than the diesel fuel
mode and diesel savings up to 83% at 8 KW load. In emissions part the EGT , NOx and smoke
emissions in dual fuel mode operation are lower as compared to diesel mode but the
Hydrocarbons (HC), CO and CO2 emissions in dual fuel mode is higher as compared to the
diesel mode.

S. Dasappa et al. [2] have discussed about the methodology and analysis towards choice of
diesel vs. dual fuel operation to meet the specific power requirements. They have done
performance and evaluation of both the engine and gasification based system. They too
compared the exhaust emissions CO and NOx in diesel and dual fuel mode.

Ali Pardarbinda Samal et al [3] experimental studies on proximate analysis, ultimate analysis,
calorific value, and ash fusion temperatures of different components of three woody biomass
species, namely, Ficus benghalensis (local name, Banyan), Ficus religiosa (local name, Pippal),
and Madhuca longifolia (local name, Mahua) have been carried out to evaluate their power
generation potentials. Among all the studied biomass species, the leaves of both Pippal and
Mahua, followed by the bark of Banyan, were found to have the highest calorific values and
highest hydrogen contents.

On the comparison in diesel savings, they found at peak load the diesel saving is 14.4 lit/hr
which is 78.7% more efficient than diesel mode. The SFC is found about 1kg/KWh of biomass
along with about 55ml/KWh of diesel. In the part of emissions the CO emission is very much
high at low load condition versus diesel mode but when load increases subsequently the CO
emission decreases simultaneously in dual fuel mode. On the other hand the diesel engine CO
emission has initially decreased and then increases after load of 43 KW and becomes maximum
at peak load (at 60 KW). Whereas the NOx emissions of dual modes are lower than the diesel
mode.

In the first review paper of Peter Mckendry [4], he discussed the basic overview of biomass.
He presented the basic chemistry of possible biomass which is present on earth. He also
discussed their biological reason of working as biomass. He performed proximate and ultimate
analysis over different biomass and finally conclude a result that the quantity of woody dry
biomass holds the potential energy production capacity. Out of different biomass herbaceous
plants and grasses are the main types of interest for producing energy, with attention focused on
the C4 plant species.

In the second review paper of Peter Mckendry [5], he discussed the different methods of
conversion of biomass such as thermo-chemical and bio-chemical methods. He finally concluded
selection of conversion for biomass is basically depends upon the form in which energy is
required. He harvests that pyrolysis, fermentation and mechanical extraction (trans-esterification)
produces liquid fuels suitable for use as transportation fuels. Only gas from gasification/pyrolysis
and AD (Anaerobic Digestion) is currently a cost-effective fuel.

In the paper of Antony Anukam et al. [6] they have discussed the different pre-processing
methods such as Size reduction, Drying, Pelletising, Briquetting and Torrefaction and different
gasifiers with their working and their comparison and after that the pre-processing of SCB
(Sugarcane Bagasse) is done with various gasification systems to get the best combination of
gasifier & pre-processing method, which is process of improving the energy from the SCB.

So far biomass production they conclude that torrefaction is the best pre- processing method as it
is having only single advantage of low volumetric energy density using downdraft gasifier