Date Palm Waste as a RE Source in Egypt. A technical and economic analysis

Table of Contents

Chapter 1: Introduction
1.1 Thesis objective
1.2 Literature research
1.3 Outline of the thesis

Chapter 2: Theoretical background
2.1 Introduction to Bio Energy
2.2 Bio feedstock and types
2.3 Biomass technologies
2.4 Introduction to date palm trees
2.5 Types of dates

Chapter 3: Methodology

Chapter 4: Date palm production and poultry waste in Egypt
4.1 Date palm waste production in Egypt
4.2 Poultry production and waste in Egypt

Chapter 5: Characterization of fuel
5.1 Ultimate analysis of date palm leaf stem before and after drying
5.2 Proximate analysis of date palm leaf stem before and after drying
5.3 Moisture content

Chapter 6: Grinding and Pelletization
6.1 Grinding
6.2 Grinding process of date palm leaf stem
6.3 Pelletization
6.4 Pelletization process of date palm leaf stem

Chapter 7: Transportation and storage of biomass
7.1 Transportation
7.2 Transportation characteristics
7.3 Transportation barriers
7.4 Storage management
7.5 Storage characteristics
7.6 Storage barriers

Chapter 8 : Gasifier
8.1 Gasifier types and process
8.2 Dual fluidized bed gasifier
8.3 External circulating concurrent moving bed gasifier
8.4 Entrained flow gasifier
8.5 Loki Unit

Chapter 9: Experimental procedure
9.1 Combustion of wood pellets
9.2 Combustion of date palm leaf stem pellets
9.3 Combustion of date palm leaf stem mixed with chicken manure

Chapter 10: Economic analysis
10.1 Harvesting costs
10.2 Processing costs
10.3 Transportation and storage costs
10.4 Gasifier and CHP costs
10.5 Final energy costs

Chapter 11: Results and discussion
11.1 Results
11.2 Discussion

Chapter 12: Environmental and socio-economic impacts
12.1 Environmental impacts
12.2 Socio-economic impacts
12.3 Measures to reduce environmental socio-economic impacts:

Chapter 13: SWOT Analysis

Chapter 14: Conclusion and Future scope
14.1 Conclusion
14.2 Future scope

References

Appendix

Abstract

In this fast-moving world, what people need is quantity and quality products. Starting from food, finished goods and products, textiles, technology. For everything, the most important resource we need is energy. It can be any form i.e., heat, electricity, steam, vapour. To produce energy, we explore and exploit the natural resources to meet the huge demands and therefore making the environment polluted. The best way to decrease the environmental pollution is to hybridize the use of fossil fuels along with the available natural renewable energy resources in the region with equal mix according to the weather conditions, topography, water resources and ecology. In this thesis we are going to discuss about one such type of renewable energy, bioenergy, in the region Egypt, where the biomass, date palm trees are grown and cultivated from several centuries. The waste of the date palm trees which in abundantly available i.e., leaf stem has a huge potential with its high HHV, calorific value and low moisture content as a renewable energy source additionally, chicken manure as a supplement to use the natural resources to the core and how can it be utilized to cut down the fossil fuel resources and increase use of renewable energy. The technical analysis deals with the fuel characterization i.e. (date palm leaf stem) for the ultimate and proximate analysis, where the former determines the C, O, N, and H content in the biomass, the latter determines the Fixed Moisture and Carbon, Ash Content and Volatile matter content in the biomass in comparison with wood. The processing of date palm leaf stem, from the harvesting site, the transport and storage methods depending on the type of application and quantity, the biomass conversion in the gasifiers, experimenting and comparing values of mass loss, temperature whether, it can replace wood and hybridize with fossil fuels in the real-world market to produce electricity. The economic analysis deals with the cost calculations for all the technical analysis process with reference to CAPEX (Capital Expenditure), OPEX (Operation & Maintenance Expenditure) with respect to Egypt, the best suited methodology, environmental-socio impacts, SWOT analysis identifying chances and challenges, feasibility of the biomass technology compared with wood and suggesting the potential to hybridize with fossil fuels, with limitations of emissions factor, ash disposal and chlorine control, achieving biomass energy production through date palm waste on a large scale run in the near future.

List of Abbreviations and Acronyms

Loki Large-scale Oven for Kinetics Investigation

FC Fixed Carbon

VM Volatile Matter

C Carbon

Cl Chlorine

S Sulphur

O Oxygen

H Hydrogen

db Dry basis

N Nitrogen

NOx Nitrogen Oxides

SOx Sulphur Oxides

HHV High Heating Value

LHV Low Heating Value

CO Carbon monoxide

UZ Upper Zone

LZ Lower Zone

l Liter

L.E Livre égyptienne

CHP Combined Heat and Power

kw kilowatt

kwh kilowatt per hour

NGA Northgate Arinso

RE Renewable energy

Chapter 1: Introduction

In the recent time, as the natural resources i.e., (coal, natural gas) being depleted, the whole world must look up for another alternative to meet the demands and fulfil people’s needs. The alternate resource to substitute the fossil fuels is renewable energy, which can be processed, optimized, and utilized with less environmental, socio impacts and meet the demands. There are different types of renewable energy sources from the nature or environment Bio, Geo-thermal, Hydro, Solar, Tidal and Wind energy. All, these different types of energy sources are available throughout the globe depending on their topography, geographical and natural sources. So, scientists and researchers are working together on particular type of energy source, which is abundantly available in that region to maximize the renewable energy potential usage, and thereby creating an earth, which can provide the natural resources and an environment as previous centuries.

1.1 Thesis objective

The main objective of this thesis is to increase the usage of natural sources available in Egypt, therefore by increasing renewable energy usage efficiently and economically. Tons of date palm waste are being burned or buried without any use, so this thesis helps to understand the importance of the material in the region, how it can change the country’s energy production by series of experimental trials and analysis thereby, promoting green energy. Along with the date palm material, how other locally available resources from animals e.g. (chicken manure) can be mixed and used as a supplement for the material availability also being acknowledged.

Another objective is to analyze whether it is economically feasible to use date palm leaf stem, compared with another biofuel, i.e.(wood) and hybridize the energy production with fossil fuels.

1.2 Literature research

Date palm (Phoenix dactylifera) arguably, the most ancient of the world’s cultivated crop, with going back 10,000 year ago 29. At present date palm is cultivated across a large belt encompassing numerous countries of stretching 8,000 Km from east to west and 2000 Km from north to south. All-in-all, about 3% of the world’s cultivable surface is believed to be occupied by the date palm [29, 39]. The present research has limited to fuel characterization and suggesting the date palm seed, followed by leaf, stem has high HHV and can be used as an alternate renewable energy resource with appropriate energy conversion technologies. There have been suggestions, literature research and case study that the material or feedstock can be used as a biofuel but, surprisingly no serious experiments have been conducted or made this biomass technology commercial using date palm even on a small scale start up. The reports suggest that it can serve as a potential of valuable feedstock for solid, liquid, and gaseous fuels. In an attempt, this thesis promotes in identifying and giving an insight of how important is to recycle and reuse the locally available resources in each particular region, reducing the CO2 emissions, achieving sustainability by hybridizing, generating employment opportunities and creating awareness for the future generations on recycling.

1.3 Outline of the thesis

This thesis describes about the biomass conversion and how the waste from the plants and animals can be recycled and utilized in a useful energy to reduce the usage of fossil fuels and decrease the carbon emissions. Chapter 2 describes about the biomass, types, technologies followed, practiced and date palm. Chapter 3 gives an insight about the methodology how the whole thesis is being experiment and economic analysis using suitable approach and technology suited for Egypt. Chapter 4 about the potential of date palm and chicken manure in Egypt as RE. Chapter 5 emphasis on grinding and pelletizing. Chapter 6 explains about the transportation and storage technologies. Chapter 7 and 8 deals with the characterization of fuel and gasifiers where the biomass is converted into useful form of energy. Chapter 9 explains the experimental procedure which was done at Umsicht laboratory. Chapter 10 deals with the economic analysis of using date palm waste as an alternate source in Egypt. Chapter 11, briefs about the results obtained and discussion how to optimize energy and cost, emission control. Chapter 12 gives an outlook of environmental and socio impacts. Chapter 13 discuss about SWOT analysis. Chapter 14 briefs the conclusion and future scope of the thesis which gives an idea how to hybridize, develop, minimize the drawbacks, implementing on a large scale and reference to other nations.

Chapter 2: Theoretical background

In this chapter we discuss about the bio energy, feedstock and types, biomass conversion technologies introduction to the date palm trees and types of date available.

2.1 Introduction to Bio Energy

Bio energy is a field of renewable energy source to produce energy used for domestic and industrial applications. Bio refers to the feedstock or material naturally obtained from plants and animal waste. Bio energy can be of liquid or gaseous state, which can be utilized according to different applications. Biomass is “carbon-neutral”, or zero carbon emission fuel as the amount of carbon it absorbs while growing is the same as the amount it produces when processed and gases released into the atmosphere.

2.2 Bio feedstock and types

Bio feedstock are the raw material derived from plants and animals. They can be of different forms, types and in different geological conditions. Depending on the type of atmosphere, weather conditions different feedstock is available and should make the best use out of these feedstocks. Each feedstock has their own properties depending on their nature of availability, moisture content, carbon content ash content and size of availability.

There are different types of feedstock available on earth, forest waste, agricultural residues, plant waste, animal waste, organic waste, municipal solid waste etc. These feedstocks when treated or processed by different methods and conditions according to the application and output required.

2.3 Biomass technologies

There are different types of technology to convert the biomass or feedstock into useful energy (electricity, heat, steam).

- Thermo chemical conversion: combustion, gasification, pyrolysis, etc.
- Biological conversion: fermentation, digestion, etc.
- Mechanical conversion: compression and pressing, chipping, etc. 1

2.3.1 Thermo chemical conversion

Combustion is a thermal decomposition process where the biomass is oxidized with excess natural air

at 800 to 1000 °C in a high pressure boiler to generate steam or direct firing where the gases are released, the biomass are burned into ashes and collected in the storage unit, further, the steam or gases are processed and connected to the steam turbine or CHP unit to produce electricity or heat. For percentages above 10 % or if biomass and coal are burning separately in different boilers, known as parallel co-firing, then changes in mills, burners and dryers are needed. 1

Gasification is a thermo-chemical conversion of a carbonaceous fuel at temperatures 500 – 800 °C, involving partial oxidation of the fuel elements. The result of the gasification is a gas called syngas. Syngas consists mainly of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), water vapour (H2O), methane (CH4), nitrogen (N2), some hydrocarbons in very low quantity and contaminants, such as carbon particles, tar, and ash. 1

Pyrolysis is a thermal decomposition of biomass in the absence of oxygen at temperature 430 – 550 °C, whereby solid carbonaceous feedstock is vaporized by heating, and result in residue consisting of char and ash. The ratio of products is influenced by the chemical composition of biomass fuels and the different parameters. 1

2.3.2 Biological conversion

Fermentation is a biological anaerobic process where the glucose content in the biomass is break down to form alcohol or acid. There will be a biological chemical reaction when bacteria or the yeast are introduced in the pile of biomass where the bacteria feeds on the biomass which produces methane and ethanol gases which can be further processed for energy production. 1

Anaerobic digestion is a biological process of breaking down the complex molecules of the plant or animals waste into simple molecules by microorganisms in the absence of oxygen. The animal and plant waste collected from the environment is put in a digester for two to three weeks and stirred constantly which produces methane referred as Biogas, and the process is called Anaerobic digestion. The gas can be further used by connecting to the CHP unit to produce heat and electricity. The gas can be produced from different plant waste, human waste, animal waste, vegetable waste, fruit waste etc. 1

2.3.3 Mechanical conversion

Compression and Pressing It is a physical mechanical process where the biomass is compressed in a

pellet machine against the dye and pressed by the rollers to and extruded in the form pellets or briquettes. This type of conversion is easy and convenient to transport and store the biomass. This improved the biomass industry by increasing fuel density, strength, and high energy release from a single pellet there by increasing efficiency 1.

Chipping is also a mechanical process where the huge biomass is cut into small pieces or in the shape of chips so that the material can be fed easily from the feeder or form conveyor belt. Mostly woody and agricultural biomass are grinded to reduce the size of the feedstock improving the fuel flow into the gasifier 1.

2.4 Introduction to date palm trees

Phoenix dactylifera, commonly known as date or date palm, is a flowering plant species in the palm family 4. Even though its cultivation is not known yet exactly it probably originated from the fertile crescent region straddling between Egypt and Mesopotamia. The date palm leaves are widely cultivated in North Africa, Middle Eastern, Africa and the South Asian countries as it has hot and tropical climatic conditions. Date palm trees typically reach about 21–23 meters (69–75 feet) in height growing single or forming a clump with several stems from a single root system [3, 37]. Date fruits (dates) are oval-cylindrical, 3 to 7 centimeters (1.2 to 2.8 in) long, and about 2.5 centimeters (0.98 in) in diameter, ranging from bright red to bright yellow in color, depending on variety. They are very sweet, containing about 75 percent of sugar when dried [3, 37].

Dates are an important traditional crop in Egypt, Iraq, Iran, Arabia, and North Africa west to Morocco. Dates (especially Medjool and Deglet Noor) are also cultivated in America in southern California, Arizona, and southern Florida in the United States and in sonora and baja California in Mexico. Date palms can take 4 to 8 years after planting before they will bear fruit, and start producing viable yields for commercial harvest between 7 and 10 years. Mature date palms can produce 150–300 lbs. (70–140 kg) of dates per harvest season. To obtain fruit of marketable quality, the bunches of dates must be thinned and bagged or covered before ripening so that the remaining fruits grow larger and are protected from weather and animals that also live off of it, such as birds [4, 3].

Date palms require well-drained deep sandy loam soils with pH 8-11 9. The soil should have the ability to hold the moisture 9. The soil should also be free from calcium carbonate 9. Date palm trees do not require, water surroundings, as they are tolerant to humidity, drought, and salinity. Date palm trees require lot of water only during the fruit-bearing season [4, 3, 10].

Date Palm Trees are of two types:

1. Male Date Palm Trees
2. Female Date Palm Trees.

Male Date Palm trees pollinate which is like (sperm cells) which has bunch of flowers and it is produced near the axis of the leaves 10.

Female Date palm leaves produce flowers (sheath) that turn into seed and later a tasty date fruit.

Generally, pollination is done by the insects or the wind by sucking the nectar from the flower and then passing on the female plant or vice versa, the wind blowing the air from one male plant to female plant or vice versa. However, due to uncertainty we are forced to do it manually. First, we collect the pollens from the sheath of the male date palm tree and then the flowers are extracted by tapping and shaking the flowers vigorously 10.

After processing it, its dried and female trees produce a sheath which is alike male. When they (female trees) begin to split, we open them up to reveal inside the fruit strands. We separate each strand, tie them together, and then hand-pollinate them with the dried pollen we collected from the male trees. Each female tree is pollinated up to three times during the process, and this process helps in developing lot of fruit buds along each strand. Normally, the manual pollination is done through ladder by the skilled labour or by the wind machines [4, 10].

All date palm tree yield products find economic value. Its trunk furnishes timber; the midribs of the leaves supply material for crates and furniture; the leaflets, for basketry; the leaf bases, for fuel; the fruit stalks, for rope and fuel; the fiber, for cordage and packing material; and the seeds are sometimes ground and used as stock feed. Syrup, alcohol, vinegar, and a strong liquor are derived from the fruit.

When a palm is cut down, the tender terminal bud is eaten as a salad. Used in the construction of houses, boats, and bridges that cross canals. They are used to make grids and fences. Elastic fibers that the cover the trunks are used to make camel and horse saddles. Mats, plates, and baskets are made with stalks. Among the other things made with palms are dye, paper, surfboards, and wax. Waste collection currently is done manually or make a pile and burnt. Some farmers use for cooking, some use it for heating of the houses. Mostly the stem and bark are used in making tables and chairs 4.

The Middle East is the source of two thirds of the world's date production. The major date producers are given in the following table.

Abbildung in dieser Leseprobe nicht enthalten

Table: 2.1 Major date producers [5, 36, 38]

2.5 Types of dates

- Barhi - Syrupy rich soft date, the softest and most fragile.
- Dayri - Heavy, sweet flavored soft date.
- Deglet – Noor sweet delicate flavored semi-dry date; known for its “true” date flavor.
- Halawy - Also halawi, sweet honey-flavored soft date.
- Khadrawy - Also khadrawi, rich, not overly sweet, flavored soft date.
- Medjool - Also medjul rich, deliciously sweet soft date with little fibrous texture.
- Thoory - Sweet, nutty flavored dry date.
- Zahidi - Sweet sugary flavored semi-dry date, medium sized fruit. The highlighted ones are generally available in the markets with deglet being semi dry and queen of dates produced in most of the Middle Eastern countries, and medjool being the soft and juicy dates, which are widely available in USA 8.

The date palm trees have several biproducts from the different parts of the tree

- Leaves
- Stem
- Bark
- Fruit
- Seeds

Leaves are generally used as a biofuel or as a biomass, where with all the waste material of the tree put in a digester to produce the Methane gas. It is observed that it yields 67% of methane gas is produced which makes it a very good biogas producer and more over it can be good feedstock for the manufacturing and industrial companies which require high amount of electricity. It can also be used a fuel for cooking as it has a good calorific value. The leaf used as roof of house during summers, making doors for temporary houses and ventilations. Mid ribs and end part of the leaves are used a fuel for cooking, making small furniture, by the fisherman for preparing the nets. Leaflets are used for making baskets for storing household products, hats, mats for sleeping, chord, which helps in horticulture, and hand brooms [4, 11], the figure 2.1 below illustrates the date palm leaflet.

Abbildung in dieser Leseprobe nicht enthalten

Fig: 2.1 Schematic diagram of date palm leaflet 11

Stems mainly used for their wood as Pillars, planks, beam or supporting some of the objects due to their high tensile strength. The main common thing the stems are used are for cooking and for heating purpose by the local people in Egypt 11.

Bark are generally the fiber kind of substance which are used as a manure for the plants when soaked in water and the fiber kind of substance acts a good protein for the growth of plants. It is used as a secondary burning small scale heating purpose 11.

Fruits, generally, serve as a sweet or as a staple food used as different types. It can be used as a salad for dressing of the food 11.

Seeds of the date palm fruit is used as a food for cattle and poultry. The oil inside the seed can be used for cosmetics and soaps. It can be burned to make charcoal and having the highest HHV value than leaf and stem but as now a days the hybrid variety i.e. (seedless varieties) are preferred and seed variety of fruit must be sold along with seed, involving collection of seeds which increase in the financial costs, seed was ruled out 11.

Chapter 3: Methodology

In this chapter we discuss the approach used and followed for technical and economic analysis as shown in the figure 3.1, how the technical and economic results, values are obtained, comparing with the reference fuel and conventional form of energy production, environmental-socio impacts and conclude the potential of the feedstock technically and economically feasible for a sustainable energy production.

Abbildung in dieser Leseprobe nicht enthalten

Fig: 3.1 Schematic diagram of methodology of thesis 21.

3.1 Bottom -up approach

In this approach the manufacturer or the planner first identifies the biomass feedstock available from the natural resources of the region, then process depending on material characteristics, weather conditions, transport and storage adaptable to the local market and convert the material into a useful energy which is efficient and economical, where a transparent and homogeneous approach is created, which in turn influence the costs as well as the utilization of resources.

The fuel or feedstock, considered is date palm leaf and stem waste which has been imported from Egypt, has been grinded into fine powder and dried in drying cabinet for 48 hours to absorb the moisture present in the fuel. The biomass is mixed accordingly weight of the tree. 75% of stem or trunk and 25% leaf. To use natural resources to the core in Egypt and yearlong availability of the fuel, we make use of chicken manure as a supplement to mix with date palm leaf stem material. So, date palm

leaf stem powder, date palm leaf stem mixed with chicken manure are the two material which is being experimented and compared with wood to check the potential of the fuel. Then, the fuel is dried for moisture content, grinded, characterized by ultimate and proximate analysis before and after drying of the fuel. The dried powdered material is being mixed with 15% of water for better binding and adhesive, converted into densified pellets with a pelletizing machine located at Fraunhofer Umsicht for increasing the efficiency of the fuel and process.

These pellets i.e. date palm leaf stem pellets, date palm leaf stem mixed with chicken manure pellets are being experimentally combusted with optimum parameters of air and temperature in a combustion unit at Fraunhofer Institute. The results obtained are as graphs of various parameters like temperature, mass loss and gas release. These results are being compared against the wood pellets which have been also combusted, determining the potential of the date palm material pros and cons. The combustion process can be shown in the figure below 3.2.

Abbildung in dieser Leseprobe nicht enthalten

Fig: 3.2 Schematic diagram of combustion process 21.

Economic analysis of all these processes on a working model phase with assumptions which is more suitable and efficient according to Egyptian standards and costs are calculated with respect to CAPEX, OPEX for a medium sized 400 kw plant from different reference papers and statistics. Finally, the cost of the energy produced form natural gas is compared to cost from the date palm leaf stem per kw/ h to assess whether is it feasible to use date palm waste as a natural biomass to produce energy. Finally, the approach which is best suited for Egypt is bottom up, which identifies the biomass on local scale, characterizing it and testing its utilization in pilot experiences later in the project.

The approach is deterministic, using validated technology i.e. (combustion) resulting the feedstock potential to substitute and hybridize, simple economic calculations for all the technical process carried out, to use the technology in a most efficient way resulting the energy produced per kwh. The tool to calculate economic costs was excel sheet.

The Environmental and socio impacts, how improvisation can be done from Egyptian market point of view. SWOT analysis for this type of biomass technology. The whole thesis experiments have been carried out at Fraunhofer Umsicht.

The thesis results would be given to Giz to implement this renewable energy proposal in an agenda for the Egyptian energy market and country development from 2023 after the youth employment and roof top solar panels scheme which is currently implemented until 2022.

Chapter 4: Date palm production and poultry waste in Egypt

In this chapter we discuss the potential of date palm and chicken manure production and availability.

4.1 Date palm waste production in Egypt

Annual date production of dates has increased by 30,000 tons, i.e. 27,215,542 kg which is 70% more likely in the year 2019 32. One healthy plant gives 90 to 100 kgs of dates and there are 12,827,235 the amount of date palm leaves on an average per Adult date palm tree is 20-40 kgs annually. An adult date palm has approximately 100 to 125 green leaves with an annual formation of 10 to 26 new leaves [12, 13]. Field studies and research, together with experience in this field, have shown when pruning palm trees on a regular basis, one palm tree can give an average of 10-15 leaf’s; the weight of the each is 2 kg before moisture loss, which reaches 60 % of the weight. The weight of the pulverized leaf is 0.75 kg, and it gives about 2.5 kg of fiber. In general, a single palm if trimmed regularly, can give about 25 kg of waste per year. The weight of the stem and bark accounts 60 %. Date palm seed, leaf, stem has a high heating, calorific value and has very good potential to replace wood, coal to produce electricity. Egypt which is a major producer of date palm producer in the world should take advantage of date palm waste as a renewable energy source with environmental improvisations, set an example for the rest of the world to use the natural available resources for producing energy and there by contributing in GHG reduction [12,13] figure 4.1 illustrates the schematic diagram of date palm tree.

Abbildung in dieser Leseprobe nicht enthalten

Fig: 4.1 Schematic diagram of date palm tree 33.

4.2 Poultry production and waste in Egypt

Egyptian poultry industry has evolved significantly for Egyptian agricultural production and energy sector. Earlier times growing poultry in the backyard farms was a traditional activity that supported the well-being of particular household activity, using their manure for burning has been practiced but, now backyard poultry production for household consumption in the overall national poultry production became minimal to rural areas. Since middle of the 20th century there have been various vectors and conditions for poultry sector development in Egypt. The socialist era is known for its subsidies and support. Today, the poultry industry in Egypt is predominantly market driven finding its way into the global market 14.

The chicken production in Egypt consists of Layer and Broiler with broiler making up the largest percentage share with 96 %. The Egyptian poultry sector produces 1.1 billion broilers every year. Layer breeds constitute only 3 to 4 % of the total Egyptian poultry production, don’t have a huge market as they are limited in some areas and the demand is higher for broilers than layers due to the breeding system, advanced poultry market and government subsidy to the broiler breed 14.

The top governorates for the chicken broiler production are Sharkia, Minya and Behera, Gharbia, Qalubiya, Dakahila which account for 18 %, 17 % and 12 %, 10 %, 9 %, 8 % respectively. The layer production is high in Sharkia, which accounts for 24 % of all layers. This is followed by the governorates of Cairo 12 %, Qalubiya 12 %, Behera 10 %, Giza 8 %, Dakahila 8 % and Gharbia 8 %.

Cattle and Poultry residues, the analysis estimated that, at national level, around 6 million tons of chicken manure and 57 million tons of cattle manure produced each year. Since cattle manure has a lot of uses in household activities, soil amendment, plant manure and various traditional activities, chicken manure has been considered in this thesis. The chicken manure being wasted or burnt on open grounds, to use it in a useful way and to reduce the use of fossil fuels, chicken manure be used as a biomass.

In conclusion, Egypt has a huge poultry production to use chicken manure as a mix with the date palm leaf and stem for bio energy production to reduce the exploitation of natural gas resources, oil reserves and limit use of coal for electricity production. The high heating value of chicken manure makes a perfect mix with date palm leaf stem waste technically and economically feasible with limitations of environmental impacts which can be improved 14.

Chapter 5: Characterization of fuel

To, understand the chemical composition and characterization of biomass is fundamental to analyse the utilization of the raw material for pre-treatment (drying, compaction) thermal decomposition and research & development of the fuel for further experiments. The fuel cannot be characterized generally e.g. wood as each tree chemical composition varies. On its research, Vassilev et al. confirmed that there are significant differences in the chemical composition of biomass varieties, conclusion derived from the study of the chemical composition of at least 86 different types of biomass 19.

The main elements include carbon (C), oxygen (O) and hydrogen (H). These elements are essentially responsible for the energy content or the calorific value of the fuel. With 47 to 50 % by weight in dry basis (db), wood fuels have the highest carbon content, while most non-wood fuels usually have a carbon content of 43 to 48 %. The oxygen content is between 40 and 45 % in dry basis. The content of hydrogen in biomass is between 5 and 7 % 19.

The elements nitrogen (N), potassium (K), magnesium (Mg), sodium (Na), calcium (Ca), phosphorus (P), Sulphur (S), silicon (Si) and chlorine (Cl) are among the secondary elements. Si and S are the only ones that are not main nutrients in plants. The so-called secondary elements or ash forming elements are usually regarded as undesirable complementary elements. They are associated to and undesirable cases in thermochemical processes. They often interact with other interfering elements in the fuel. The six plant nutrients play an important role in the composition of biomass besides, they play an important role as fertilizer additives 19.

In addition to the main and secondary elements, biogenic solid fuels contain a whole range of different trace elements, most of which are also heavy metals (i.e., iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), cobalt (Co), lead (Pb), aluminum (Al), chromium (Cr), cadmium (Cd), nickel (Ni), mercury (Hg), arsenic (As)). Some of these trace elements are considered essential micronutrients, while others can be harmful to plants 19.

Trace elements (As, Fe, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Zn) are of relevance for ash melting, deposit formation, fly ash and aerosol emissions as well as corrosion (together with S and Cl. The contrast to the main elements, the fluctuation margins for trace elements are considerable. During combustion, a fraction of the ash-forming compounds in the fuel is volatilize (especially K, Na, S, Cl, Zn, Pb, Cd, to some degree) and they are released to the gas phase. The volatilized fraction depends on the chemical composition of the fuel, the gas atmosphere, the temperature, and the combustion technology used. Due to the high volatility of Cd, Zn and Pb, it is possible to find their presence in the aerosol fraction depending on the heavy metal concentration in the fuel 19.

The nitrogen (N) content in biogenic solid fuels has a direct effect on the formation of nitrogen oxides (NOx) since this element is usually converted completely into the gas phase during combustion. The oxidation of the amount of nitrogen bound in the fuel is the most important NOx forming mechanism. In a small extent, the fuel nitrogen can also promote the formation of nitrous oxide (NO). The N contents in the leaves or needles are from 1.0 % to 2.8 %. The fluctuation margins of N contents are greater for all non-wood fuels than for wood 19.

Potassium (K) is involved in corrosion processes in heat exchangers and exhaust gas components of combustion plants. Moreover, in junction with Na it can form gaseous alkali chlorides during combustion, which condense on heat exchanger surfaces or as fly ash particles during cooling. On heat exchangers, they react with Sulphur dioxide (SO2) from the exhaust gas to form alkali sulfates, thus molecular chlorine (Cl2) is formed. Besides, K is one aerosol-forming element that can cause an increase in particle emissions during combustion. Nonetheless, it also influences the softening behavior of the ash by decreasing the melting point. In most cases, a big share of the potassium content is bound into the ashes. In trees, the highest concentrations of K are found in needles and leaves (approx. 0.6 to 1.3 %) 19.

Calcium (Ca) in the combustion process increases the melting point of the biomass ash. For fuels with unfavorable ash softening behavior, the ash melting point can be therefore increased by using additives based on Ca (e.g., lime). It can also influence the behavior of other elements during combustion. High alkaline earth contents (especially Ca) lead to large parts of the Sulphur in the fuel to remain in the ash and therefore not being found in the exhaust gas as SO2. The Ca content is comparatively high overall at 0.3 to approx. 1 % 19.

Sulphur (S) content primarily determines the SO2 emissions. Legal frameworks regulate the release of this component to the atmosphere. Most of the Sulphur passes into the gaseous phase, forming SO2, SO3 and alkali sulphate stages. As chlorine, during the cooling of the flue gases in the boiler, sulphate

can deposit on the fly ash particles carried either along or on the heat exchanger surfaces. The

dedusting equipment can collect from 40 % to 90 % of the Sulphur incorporated into the ash. S can also be indirectly responsible for increased corrosion on the heat exchangers. The highest concentration of Sulphur in biomass is found in needles and leaves, from 740 to 1930 mg/kg, while the S content of bark is usually at least the half of this value. Other example is pure hardwood, which contains less than a twentieth of the S value found in leaves or needle 19.

Chlorine (Cl) content importance is its involvement in the formation of HCl. Despite the relatively high concentration of Cl in the ash of 40 to 95 %, HCl emissions can become problematic for certain Cl rich fuels (e.g., cereal straw) and make secondary exhaust gas treatment measures necessary. In addition, Cl in combination with alkaline earth metals and with SO2, has a corrosive effect on the surface of the heat exchangers. It is also one of aerosol forming element and it can cause an increase in particle emissions during combustion. Due to its presence as a complementary substance in fertilizers, biomass from fertilized field crops have significantly higher chlorine contents than wood. The concentration of chlorine in wood fuels range from 0.005 to 0.02 % in dry basis. In contrast, the Cl content of cereal straw is many times higher at approx. 0.2 to 0.5 % 19.

5.1 Ultimate analysis of date palm leaf stem before and after drying.

Ultimate analysis helps in the chemical composition of elements in the biomass. Ultimate compositions assess the percentage of N, S and Cl to determine the environmental impacts when a specific biomass under investigation is gasified or combusted. Heating value of the fuel can be estimated from the ultimate analysis as it determines the C and H percentages. The table 5.1 below shows the values of ultimate analysis of date palm leaf, stem, before and after drying, wood and chicken manure.

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Table: 5.1 Ultimate analysis of date palm leaf stem, wood, and chicken manure (Courtesy: Fraunhofer Umsicht)

5.2 Proximate analysis of date palm leaf stem before and after drying.

Proximate analysis table 5.2 determines the volatile matter (VM), fixed carbon (FC) and ash content (AC), the latter being of extreme importance when the biomass feedstock undergoes by combustion or thermochemical conversion. High ash content at high temperatures may lead to various technical problems such as slagging and fouling in the combustion chamber or heat exchanger. The volatile matter of the biomass feedstock is usually driven off during pyrolysis or gasification at elevated temperatures, while the fixed carbon takes more time to be converted to CO2, than the volatile matter leaving behind the inorganic ash (the non-volatile biomass fractions) after complete combustion. The knowledge about the impurities present in the biomass feedstock would help in the design of suitable flue gas cleaning systems and the requirement to add certain additives to raise the ash fusion temperature to that above the operation temperature which is a very important technical study for a successful biomass selection for the process, type of gasifier, exhaust piping and cleaning system 19.

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Table: 5.2 Proximate analysis of date palm leaf stem, wood, and chicken manure (Courtesy: Fraunhofer Umsicht)

5.3 Moisture content

Biomass from the plants, animals have high moisture content as they are directly exposed to the various environmental factors like wind, moisture, rain, and different gases in the atmosphere. The moisture content will always be a huge influential factor for the biomass during gasification and combustion process. It has a huge impact on its heating value and the rate at which it releases the energy. The moisture content of the woody biomass like palm leaf, stem, pine wood, have relatively less moisture content than other plant or animal waste derived biomass. So, calculating the moisture content is one of the important factors to improve the efficiency of the biomass as a fuel.

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