Energy Value of Agricultural Wastes

Large quantities of agricultural wastes, resulting from crop cultivation activities, are a promising source of energy supply for production, processing and domestic activities in the rural areas. The available agricultural residues are either being used inefficiently or burnt in the open to clear the fields for subsequent crop cultivation.

agricultural-wastes

On an average 1.5 tons of crop residue are generated for processing 1 ton of the main product. In addition, substantial quantities of secondary residues are produced in agro-industries processing farm produce such as paddy, sugarcane, coconut, fruits and vegetables.

Agricultural crop residues often have a disposal cost associated with them. Therefore, the “waste-to-energy” conversion processes for heat and power generation, and even in some cases for transport fuel production, can have good economic and market potential. They have value particularly in rural community applications, and are used widely in countries such as Sweden, Denmark, Netherlands, USA, Canada, Austria and Finland.

The energy density and physical properties of agricultural biomass wastes are critical factors for feedstock considerations and need to be understood in order to match a feedstock and processing technology.

There are six generic biomass processing technologies based on direct combustion (for power), anaerobic digestion (for methane-rich biogas), fermentation (of sugars for alcohols), oil exaction (for biodiesel), pyrolysis (for biochar, gas and oils) and gasification (for carbon monoxide and hydrogen-rich syngas). These technologies can then be followed by an array of secondary treatments (stabilization, dewatering, upgrading, refining) depending on specific final products.

It is well-known that power plants based on baled agricultural residues are efficient and cost-effective energy generators. Residues such as Rice Husks, Wheat Straw and Maize Cobs are already concentrated at a point where it is an easily exploitable source of energy, particularly if it can be utilized on-site to provide combined heat and power.

The selection of processing technologies needs to be aligned to the nature and structure of the biomass feedstock and the desired project outputs. It can be seen that direct combustion or gasification of biomass are appropriate when heat and power are required.

Anaerobic digestion, fermentation and oil extraction are suitable when specific biomass wastes are available that have easily extractable oils and sugars or high water contents. On the other hand, only thermal processing of biomass by pyrolysis can provide the platform for all of the above forms of product.

Many thermal processing technologies for agricultural wastes require the water content of biomass to be low (<15 per cent) for proper operation. For these technologies the energy cost of drying can represent a significant reduction in process efficiency.

Moisture content is of important interest since it corresponds to one of the main criteria for the selection of energy conversion process technology. Thermal conversion technology requires biomass fuels with low moisture content, while those with high moisture content are more appropriate for biological-based process such as fermentation or anaerobic digestion.

The ash content of biomass influences the expenses related to handling and processing to be included in the overall conversion cost. On the other hand, the chemical composition of ash is a determinant parameter in the consideration of a thermal conversion unit, since it gives rise to problems of slagging, fouling, sintering and corrosion.

How Farmers Can Benefit from Agriculture Recruiting?

Agricultural recruiting is the process of hiring personnel with agrarian qualifications. The qualification may be in the form of diplomas, degrees, and practical experience. Farming is an art that can be learned by any individual interested in venturing into the industry. However, it takes a level of expertise to navigate the various dynamics that influence whether the farming process is a success. Let’s take a look at how farmers can benefit from agricultural recruiting.

agricultural-recruiting

1. Research

Data gathered from in-depth research is one of the ways that farmers can benefit from agriculture recruiting. As a farmer, it is tempting to plant convenient crops, season, and plants that are enjoyable. However, agriculturalists base decisions on in-depth research data.

Agriculture recruiting will provide researchers who can provide you with the following information that is crucial for the success of any crop:

  • The specific crops that grow well in your particular geographical area
  • The temperatures required for specific crops to grow in a healthy state
  • The best time of the season to plant a specific crop
  • The advantages and disadvantages of planting the crop
  • Mistakes experienced by other farmers and how to avoid these
  • Labour required for the crop
  • Gadgets needed for effective planting

Such information requires in-depth research through case study analysis, interviews with farmers, participant observation, and desk research. Expert agricultural researchers will provide such data, which will help a farmer make informed decisions regarding their crop.

2. Business Management Consulting

A farmer may be a wealth of knowledge regarding the practical execution of crop planting. They may be sure of the times to plant, the soil, and the processes it takes to yield a quality crop. If the farmer is in business, they may not have the expertise regarding business management.

The business aspect of farming requires market research, competitor analysis, market trend projection, foresight, marketing, consumer behavior, and networking. Through agricultural recruiting, a farmer is paired with an expert in such business processes. The coupling of the skills may result in farming business success.

3. Soil Testing

It is difficult to determine the type of soil that you plan to grow the crop. Agriculturalists know how to test the soil to decide various dynamics. Soil type can determine the type of crop that will raise best, the produce that will require the least labor, the kind of fertilizer that nurtures the soil type effectively, and the season that certain crops flourish. A farmer who has soil tested before beginning a planting process will have a higher success rate than one who risks planting the wrong type of produce in the soil.

4. Seed Selection

Regardless of the type of crop that a farmer decides to plant, they can choose from numerous kinds of seeds. The decision to buy a particular type of seed should depend on varying factors such as land space, soil type, and temperature. This is the kind of information that a farmer will benefit from if they venture into agriculture recruiting. You can research it yourself—however, it may be difficult to verify the knowledge freely shared in digital spaces.

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5. Expert Damage Control

Crops can succumb to factors that are sometimes out of the farmer’s control. For example, unexpected heavy rainfall, winds, or a sudden pest problem could all affect the crop’s quality. Agriculture recruiting means accessing experts of damage control in such situations. Experts will know whether crops can be salvaged from the damage and the process that is required. If the crop is damaged beyond the point where any can be nurtured to health, experts will give information regarding how to move beyond the damage. Prevention methods in some cases may also be provided for future execution.

6. Pest Management

Pest management is crucial to the success of a crop. Experts can decipher whether a crop requires a form of pest management, the kind of pest that may damage the crop, how it damages the harvest, as well as when and how to apply pest control substances. Certain chemicals may, in fact, harm the crop, or become hazardous to health if applied on the wrong type of crop. The expert advice offered to farmers is therefore essential, especially when there is the use of chemicals. Agriculturalists are also trained on how to use the chemicals, meaning farmer safety is a priority.

Conclusion

Farmers can benefit from agriculture recruiting because of expert knowledge. Farmers can benefit from in-depth research, soil testing, seed selection consultation, damage control, pest management, and farming from the business facet. It is advised that farmers consult such expertise to avoid costly mistakes and develop their farming art through expert guidance.

3 Ways to Reuse Water Using Renewable Energy

Water is essential to life, making it one of the most valuable resources on the planet. We drink it, use it to grow food and stay clean. However, water is of increasingly short supply and the Earth’s population only continues to expand. Many of the countries with the largest populations are also ones that use the most water. For instance, in the United States, the average person uses 110 gallons of water each day. Meanwhile, three-fourths of those living in Africa don’t have access to clean water.

To ensure we have enough water to survive — and share with those in need — the best approach is to conserve this resource and find sustainable ways of recycling it. Currently, conventional methods or water purification use about three percent of the world’s energy supply. This isn’t sustainable long-term and can have adverse effects on the environment.

Recently, however, major steps have been made to reduce both the collective water and carbon footprint. Now, there are multiple, sustainable ways to both save energy and reuse water using renewable energy.

1. Anaerobic Digestion

Anaerobic digestion — or AD — is the natural process in which microorganisms break down organic materials like industrial residuals, animal manure and sewage sludge. This process takes place in spaces where there is no oxygen, making it an ideal system for cleaning and reusing wastewater. This recycled water can provide nutrients for forest plantations and farmland alike.

For example, in Yucatan, Mexico, the successful implementation of AD systems has provided water to promote reforestation efforts. This system has also helped accelerate the search for a sustainable solution to water-sanitation issues in rural Latin American communities.

Additionally, anaerobic digestion also reduces adverse environmental impacts. As the system filters water, it creates two byproducts — biogas and sludge. The biogas can be used as energy to supply electricity or even fuel vehicles. And the sludge is used as fertilizers and bedding for livestock. In poor countries, like Peru, 14 percent of primary energy comes from biogas, providing heat for food preparation and electricity to homes that would not have access to it otherwise.

2. Vapor Compression Distillation

In this process, the vapor produced by evaporating water is compressed, increasing pressure and temperature. This vapor is then condensed to water for injection — highly purified water that can be used to make pharmaceutical-grade solutions.

Vapor compression distillation is incredibly sustainable because it can produce pure water on combustible fuel sources like cow dung — no chemicals, filters or electricity necessary. This makes it water accessible to even the most rural communities.

The system only needs enough energy to start the first boil and a small amount to power the compressor. This energy can be easily supplied by a solar panel, producing roughly 30 liters of water an hour using no more energy than that of a handheld hairdryer.

3. Solar Distillation

Utilizing solar energy for water treatment may be one of the most sustainable solutions to the water crisis, without sacrificing the environment or non-renewable resources. Between 80 and 90 percent of all energy collected through commercial solar panels is wasted, shed into the atmosphere as heat. However, recent advancements in technology have allowed scientists to capture this heat and use it to generate clean, recycled water.

By integrating a solar PV panel-membrane distillation device behind solar panels, researchers were able to utilize heat to drive water distillation. This panel also increases solar to electricity efficiency. This device can even be used to desalinate seawater, providing a sustainable solution to generating freshwater from saltwater.

Environmental and Economic Benefits

Finding sustainable methods of recycling water is essential to reducing energy consumption and helping the planet, and all those dependent upon it, thrive. Using methods like anaerobic digestion and environmentally-friendly distillation processes can reduce toxic emissions and provide purified, recycled water to those who need it most.

Sustainable reuse of water can also benefit the economy. The financial costs of constructing and operating desalination and purification systems are often high compared to the above solutions. Furthermore, using recycled water that is of lower quality for agricultural and reforestation purposes saves money by reducing treatment requirements.

Biogas Prospects in Rural Areas: Perspectives

Biogas, sometimes called renewable natural gas, could be part of the solution for providing people in rural areas with reliable, clean and cheap energy. In fact, it could provide various benefits beyond clean fuel as well, including improved sanitation, health and environmental sustainability.

What is Biogas?

Biogas is the high calorific value gas produced by anaerobic decomposition of organic wastes. Biogas can come from a variety of sources including organic fraction of MSW, animal wastes, poultry litter, crop residues, food waste, sewage and organic industrial effluents. Biogas can be used to produce electricity, for heating, for lighting and to power vehicles.

Using manure for energy might seem unappealing, but you don’t burn the organic matter directly. Instead, you burn the methane gas it produces, which is odorless and clean burning.

Biogas Prospects in Rural Areas

Biogas finds wide application in all parts of the world, but it could be especially useful to developing countries, especially in rural areas. People that live in these places likely already use a form of biomass energy — burning wood. Using wood fires for heat, light and cooking releases large amounts of greenhouse gases into the atmosphere.

The smoke they release also has harmful health impacts, particularly when used indoors. You also need a lot to burn a lot of wood when it’s your primary energy source. Collecting this wood is a time-consuming and sometimes difficult as well as dangerous task.

Many of these same communities that rely on wood fires, however, also have an abundant supply of another fuel source. They just need the tools to capture and use it. Many of these have a lot of dung from livestock and lack sanitation equipment. This lack of sanitation creates health hazards.

Turning that waste into biogas could solve both the energy problem and the sanitation problem. Creating a biogas system for a rural home is much simpler than building other types of systems. It requires an airtight pit lined and covered with concrete and a way to feed waste from animals and latrines into the pit. Because the pit is sealed, the waste will decompose quickly, releasing methane.

This methane flows through a PCV pipe to the home where you can turn it on and light on when you need to use it. This system also produces manure that is free of pathogens, which farmers can use as fertilizer.

A similar but larger setup using rural small town business idea can provide similar benefits for urban areas in developing countries and elsewhere.

Benefits of Biogas for Rural Areas

Anaerobic digestion systems are beneficial to developing countries because they are low-cost compared to other technologies, low-tech, low-maintenance and safe. They provide reliable fuel as well as improved public health and sanitation. Also, they save people the labor of collecting large amounts of firewood, freeing them up to do other activities. Thus, biomass-based energy systems can help in rural development.

Biogas for rural areas also has environmental benefits. It reduces the need to burn wood fires, which helps to slow deforestation and eliminates the emissions those fires would have produced. On average, a single home biogas system can replace approximately 4.5 tons of firewood annually and eliminate the associated four tons of annual greenhouse gas emissions, according to the World Wildlife Fund.

Biogas is also a clean, renewable energy source and reduces the need for fossil fuels. Chemically, biogas is the same as natural gas. Biogas, however, is a renewable fuel source, while natural gas is a fossil fuel. The methane in organic wastes would release into the atmosphere through natural processes if left alone, while the greenhouse gases in natural gas would stay trapped underground. Using biogas as a fuel source reduces the amount of methane released by matter decomposing out in the open.

What Can We Do?

Although biogas systems cost less than some other technologies, affording them is often still a challenge for low-income families in developing countries, especially in villages. Many of these families need financial and technical assistance to build them. Both governments and non-governmental organizations can step in to help in this area.

Once people do have biogas systems in place though, with minimal maintenance of the system, they can live healthier, more comfortable lives, while also reducing their impacts on the environment.

Agricultural Biomass in Malaysia

Malaysia is located in a region where biomass productivity is high which means that the country can capitalize on this renewable energy resource to supplements limited petroleum and coal reserves. Malaysia, as a major player in the palm oil and sago starch industries, produces a substantial amount of agricultural biomass waste which present a great opportunity for harnessing biomass energy in an eco-friendly and commercially-viable manner.

Peninsular Malaysia generates large amounts of wood and’ agricultural residues, the bulk of which are not being currently utilised for any further downstream operations. The major agricultural crops grown in Malaysia are rubber (39.67%), oil palm (34.56%), cocoa (6.75%), rice (12.68%) and coconut (6.34%). Out of the total quantity of residues generated, only 27.0% is used either as fuel for the kiln drying of timber, for the manufacture of bricks, the curing of tobacco leaves, the drying rubber-sheets and for the manufacture of products such as particleboard and fibreboard. The rest has to be disposed of by burning.

Palm Oil Industry

Oil palm is one of the world’s most important fruit crops. Malaysia is one of the largest producers and exporter of palm oil in the world, accounting for 30% of the world’s traded edible oils and fats supply. Palm oil industries in Malaysia have good potential for high pressure modern power plants and the annual power generation potential is about 8,000 GWh. Malaysia produced more than 20 million tonnes of palm oil in 2012 over 5 million hectares of land.

The palm oil industry is a significant branch in Malaysian agriculture. Almost 70% of the volume from the processing of fresh fruit bunch is removed as biomass waste in the form of empty fruit bunches (EFBs), fibers and shells, as well as liquid effluent. Fibres and shells are traditionally used as fuels to generate power and steam. Palm oil mill effluent, commonly known as POME, are sometimes converted into biogas that can be used in gas-fired gensets.

Sugar Industry

The cultivation of sugarcane in Malaysia is surprisingly small. Production is concentrated in the Northwest extremity of peninsular Malaysia in the states of Perlis and Kedah. This area has a distinct dry season needed for cost-efficient sugarcane production. Plantings in the states of Perak and Negri Sembilan were unsuccessful due to high unit costs as producing conditions were less suitable.

The lack of growth in cane areas largely reflects the higher remuneration received by farmers for other crops, especially oil palm. Over the past 20 years while the sugarcane area has remained at around 20000 hectares, that planted to oil palm has expanded from 600 000 hectares to 5 million hectares.

Other leading crops in terms of planted areas are rubber with 2.8 million hectares, rice with 670 000 hectares and cocoa with 380 000 hectares. Malaysia, the world’s third largest rubber producer, accounted for 1 million tons of natural rubber production in 2012. Like oil palm industry, the rubber industry produces a variety of biomass wastes whose energy potential is largely untapped until now.

Biomass Energy Potential in Pakistan

Being an agricultural economy, biomass energy potential in Pakistan is highly promising. Pakistan is experiencing a severe energy crisis these days which is resulting in adverse long term economic and social problems. The electricity and gas shortages have directly impacted the common man, industry and commercial activities.

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The high cost of energy mix is the main underlying reason behind the power crisis. The main fuel for the local power industry is natural gas however due to the continued depletion of this source and demands elsewhere the power generation companies are now dependent on furnace oil which is relatively expensive.

The way out of this crisis is to look for fuel sources which are cheap and abundantly available within the country. This description and requirement is fulfilled by biomass resources which have been largely ignored in the past and are also available in sufficient quantities to tackle the energy crisis prevailing in the country.

Biomass Energy in Pakistan

The potential to produce power from biomass resources is very promising in Pakistan. Being an agrarian economy, more than 60% of the population is involved in agricultural activities in the country. As per World Bank statistics, around 26,280,000 hectares of land is under cultivation in Pakistan. The major sources of biomass energy are crop residues, animal manure and municipal solid wastes

Agricultural Residues

Wheat straw, rice husk, rice straw, cane trash, bagasse, cotton sticks are some of the major crop residues in Pakistan. Sugar cane is a major crop in the country and grown on a wide scale throughout Pakistan. During 2010-2011, the area under sugarcane cultivation was 1,029,000 hectares which is 4% of the total cropped area.

Sugarcane trash which constitutes 10% of the sugar cane is currently burned in the fields. During the year 2010-11, around 63,920,000 metric tons of sugarcane was grown in Pakistan which resulted in trash generation of around 5,752,800 metric tons. As per conservation estimates, the bioenergy potential of cane trash is around 9,475 GWh per year.

Cotton is another major cash crop in Pakistan and is the main source of raw material to the local textile industry. Cotton is grown on around 11% of the total cropped area in the country. The major residue from cotton crop is cotton sticks which is he material left after cotton picking and constitute as much as 3 times of the cotton produced.

Majority of the cotton sticks are used as domestic fuel in rural areas so only one-fourth of the total may be considered as biomass energy resource. The production of cotton sticks during 2010-2011 was approximately 1,474,693 metric tons which is equivalent to power generation potential of around 3,071 GWh.

Cotton sticks constitute as much as 3 times of the cotton produced.

Animal Manure

Pakistan is the world’s fourth largest producer of milk. The cattle and dairy population is around 67,294,000 while the animal manure generation is estimated at 368,434,650 metric tons. Biogas generation from animal manure is a very good proposition for Pakistan as the country has the potential to produce electrical energy equivalent to 23,654 GWh

Municipal Solid Waste

The generation or solid wastes in 9 major urban centers is around 7.12 million tons per annum which is increasing by 2.5% per year due to rapid increase in population and high rate of industrialization. The average calorific value of MSW in Pakistan is 6.89 MJ/kg which implies power generation potential of around 13,900 GWh per annum.

Sustainable Agriculture with Organic Liquid Fertilizers

Agricultural practices are increasingly leaning towards committing to a sustainable environment. In light of this, organic farming has become acceptable to many farmers. Many are practicing environmental- friendly practices such as using organic liquid fertilizer instead of the synthetic alternative.

The misuse and abuse of synthetic fertilizers is responsible for many of the health problems that humans experience today. It has also contributed to a large extent to the deterioration of the environment.

Organic agriculture has experienced fast growth globally. Organic systems involve the natural management of soil through the following practices:

These nourish the soil by steadily releasing nutrients to the crops as the organic matter that has been added to the soil breaks down. The chemical and physical properties of the soil are improved by the exogenous organic matter applied to the soil. This also improves the biological functions of the soil which results in a healthy and wholesome crop free of dangerous disease causing chemicals.

liquid-fertilizer

Why Organic Liquid Fertilizer is Sustainable?

Organic liquid fertilizer is derived from naturally existing products such as plants and animal manure. This makes it a sustainable product. Waste from animals such as cows, rabbits, fish and chicken is used to make organic fertilizer that provides much-needed nutrition to plants and soil as well.

Naturally occurring vegetation and waste will always be available as it renews itself. Besides, plants can be reused to make fertilizer for the next batch once harvesting is done. Since organic farming takes care of the environment, it is safe to say that vegetation is safe for the long run. Organic liquid fertilizer is also made from human waste such as urine and that is definitely sustainable.

ecofriendly-gardening

Organic gardeners love to have a bottle of organic fish fertilizer on hand for feed young seedlings. This fertilizer also works well on plants in containers and any crop that may be suffering from ‘malnutrition’.

Why and When to Use Liquid Fertilizers

Seeing as liquid manures act faster than solid organic ones, they are the best option in the following circumstance:

  • For seedlings that have exhausted the nutrients provided by newly sprouted seed. It is especially crucial if the fertilizer you are using is a soil-free seed starting mix. While it helps in damping off, it fails to provide adequate nutrients.
  • When seedlings show signs of not having had enough nutrients. If the color fails to darken after a fertilizer has been added, it is an indication that they have not had a fair share of nutrients.
  • If you have container-grown plants, liquid fertilizers are what your plants yearn for. Container-grown plants depend entirely on the grower for nutrients and moisture. They need to be fed frequently with an organic liquid fertilizer in order to thrive.
  • When you are growing cold-tolerant crops which begin their journey of growth in low soil temperatures. Liquid fertilizers are great for boosting nutrients for such plants since it is difficult to absorb nutrients such as nitrogen in wintry temperatures.

Organic liquid fertilizers are short-acting. Consequently, they are easier to regulate that dry organic ones which are longer-acting. The ease with which liquid fertilizers can be used makes them quite popular and therefore sustainable.

Important Tip

Do not mix too much nitrogen-rich fertilizer into the soil. This is not reversible. The release of nitrogen into the soil increases as the temperature rises. You may consequently end up with huge plants but no production. The best time to apply a short-acting fertilizer is just when it is needed by the crop. Then you have less chances of overdoing the application.

When your plants are well into the season, you can feed them an organic liquid fertilizer to rejuvenate crops such as tomatoes which live long in the ground. Tomatoes are known to awaken with gusto once you give them two feeds of a good organic liquid fertilizer.

Trends in Utilization of Palm Kernel Shells

The palm kernel shells used to be initially dumped in the open thereby impacting the environment negatively without any economic benefit. However, over time, palm oil mills in Southeast Asia and elsewhere realized their brilliant properties as a fuel and that they can easily replace coal as an industrial fuel for generating heat and steam.

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Palm kernel shells is an abundant biomass resource in Southeast Asia

Major Applications

Nowadays, the primary use of palm kernel shells is as a boiler fuel supplementing the fibre which is used as primary fuel. In recent years kernel shells are extensively sold as alternative fuel around the world. Besides selling shells in bulk, there are companies that produce fuel briquettes from shells which may include partial carbonisation of the material to improve the combustion characteristics.

Palm kernel shells have a high dry matter content (>80% dry matter). Therefore the shells are generally considered a good fuel for the boilers as it generates low ash amounts and the low K and Cl content will lead to less ash agglomeration. These properties are also ideal for production of biomass for export.

As a raw material for fuel briquettes, palm shells are reported to have the same calorific characteristics as coconut shells. The relatively smaller size makes it easier to carbonise for mass production, and its resulting palm shell charcoal can be pressed into a heat efficient biomass briquette.

Although the literature on using oil palm shells (and fibres) is not as extensive as EFB, common research directions of using shells, besides energy, are to use it as raw material for light-weight concrete, fillers, activated carbon, and other materials. However, none of the applications are currently done on a large-scale. Since shells are dry and suitable for thermal conversion, technologies that further improve the combustion characteristics and increase the energy density, such as torrefaction, could be relevant for oil palm shells.

Torrefaction is a pretreatment process which serves to improve the properties of biomass in relation to the thermochemical conversion technologies for more efficient energy generation. High lignin content for shells affects torrefaction characteristics positively (as the material is not easily degraded compared to EFB and fibres).

Furthermore, palm oil shells are studied as feedstock for fast pyrolysis. To what extent shells are a source of fermentable sugars is still not known, however the high lignin content in palm kernel shells indicates that shells are less suitable as raw material for fermentation.

Future Outlook

The leading palm oil producers in the world should consider limiting the export of palm kernel shells (PKS) to ensure supplies of the biomass material for renewable energy projects, in order to decrease dependency on fossil fuels. For example, many developers in Indonesia have expressed an interest in building palm kernel shell-fired power plants.

However, they have their concerns over supplies, as many producers prefer to sell their shells overseas currently. Many existing plants are facing problems on account of inconsistent fuel quality and increasing competition from overseas PKS buyers. PKS market is well-established in provinces like Sumatra and export volumes to Europe and North Asia as a primary fuel for biomass power plants is steadily increasing.

The creation of a biomass supply chain in palm oil producing countries may be instrumental in discouraging palm mills to sell their PKS stocks to brokers for export to foreign countries. Establishment of a biomass exchange in leading countries, like Indonesia, Malaysia and Nigeria, will also be a deciding factor in tapping the unharnessed potential of palm kernel shells as biomass resource.

Bioenergy in the Middle East

The Middle East region offers tremendous renewable energy potential in the form of solar, wind and bioenergy which has remained unexplored to a great extent. The major biomass producing Middle East countries are Egypt, Algeria, Yemen, Iraq, Syria and Jordan. Traditionally, biomass energy has been widely used in rural areas for domestic purposes in the Middle East. Since most of the region is arid/semi-arid, the biomass energy potential is mainly contributed by municipal solid wastes, agricultural residues and agro-industrial wastes.

MENA_Bioenergy

Municipal solid wastes represent the best resources for  bioenergy in the Middle East. The high rate of population growth, urbanization and economic expansion in the region is not only accelerating consumption rates but also accelerating the generation of municipal waste. Bahrain, Saudi Arabia, UAE, Qatar and Kuwait rank in the top-ten worldwide in terms of per capita solid waste generation. The gross urban waste generation quantity from Middle East countries is estimated at more than 150 million tons annually.

In Middle East countries, huge quantity of sewage sludge is produced on daily basis which presents a serious problem due to its high treatment costs and risk to environment and human health. On an average, the rate of wastewater generation is 80-200 litres per person each day and sewage output is rising by 25 percent every year. According to estimates from the Drainage and Irrigation Department of Dubai Municipality, sewage generation in the Dubai increased from 50,000 m3 per day in 1981 to 400,000 m3 per day in 2006.

The food processing industry in Middle East produces a large number of organic residues and by-products that can be used as source of bioenergy. In recent decades, the fast-growing food and beverage processing industry has remarkably increased in importance in major countries of the Middle East.

Since the early 1990s, the increased agricultural output stimulated an increase in fruit and vegetable canning as well as juice, beverage, and oil processing in countries like Egypt, Syria, Lebanon and Saudi Arabia. There are many technologically-advanced dairy products, bakery and oil processing plants in the region.

date-wastes

Date palm biomass is found in large quantities across the Middle East

Agriculture plays an important role in the economies of most of the countries in the Middle East.  The contribution of the agricultural sector to the overall economy varies significantly among countries in the region, ranging, for example, from about 3.2 percent in Saudi Arabia to 13.4 percent in Egypt. Cotton, dates, olives, wheat are some of the prominent crops in the Middle East

Large quantities of crop residues are produced annually in the region, and are vastly underutilised. Current farming practice is usually to plough these residues back into the soil, or they are burnt, left to decompose, or grazed by cattle. These residues could be processed into liquid and solid biomass fuels or thermochemically processed to produce electricity and heat in rural areas.

Energy crops, such as Jatropha, can be successfully grown in arid regions for biodiesel production. Infact, Jatropha is already grown at limited scale in some Middle East countries and tremendous potential exists for its commercial exploitation.

The Middle Eastern countries have strong animal population. The livestock sector, in particular sheep, goats and camels, plays an important role in the national economy of the Middle East countries. Many millions of live ruminants are imported into the Middle Eastern countries each year from around the world. In addition, the region has witnessed very rapid growth in the poultry sector. The biogas potential of animal manure can be harnessed both at small- and community-scale.

Biomass Wastes from Palm Oil Mills

The Palm Oil industry generates large quantity of wastes whose disposal is a challenging task. In the Palm Oil mill, fresh fruit bunches are sterilized after which the oil fruits can be removed from the branches. The empty fruit bunches (are left as residues, and the fruits are pressed in oil mills. The Palm Oil fruits are then pressed, and the kernel is separated from the press cake (mesocarp fibers). The palm kernels are then crushed and the kernels then transported and pressed in separate mills.

palm-biomass

In a typical palm oil mill, almost 70% of the fresh fruit bunches are turned into wastes in the form of empty fruit bunches, fibers and shells, as well as liquid effluent. These by-products can be converted to value-added products or energy to generate additional profit for the Palm Oil Industry.

Palm Kernel Shells (PKS)

Palm kernel shells (or PKS) are the shell fractions left after the nut has been removed after crushing in the Palm Oil mill. Kernel shells are a fibrous material and can be easily handled in bulk directly from the product line to the end use. Large and small shell fractions are mixed with dust-like fractions and small fibres.

Moisture content in kernel shells is low compared to other biomass residues with different sources suggesting values between 11% and 13%. Palm kernel shells contain residues of Palm Oil, which accounts for its slightly higher heating value than average lignocellulosic biomass. Compared to other residues from the industry, it is a good quality biomass fuel with uniform size distribution, easy handling, easy crushing, and limited biological activity due to low moisture content.

Press fibre and shell generated by the Palm Oil mills are traditionally used as solid fuels for steam boilers. The steam generated is used to run turbines for electricity production. These two solid fuels alone are able to generate more than enough energy to meet the energy demands of a Palm Oil mill.

Empty Fruit Bunches (EFBs)

In a typical Palm Oil mill, empty fruit bunches are abundantly available as fibrous material of purely biological origin. EFB contains neither chemical nor mineral additives, and depending on proper handling operations at the mill, it is free from foreign elements such as gravel, nails, wood residues, waste etc. However, it is saturated with water due to the biological growth combined with the steam sterilization at the mill. Since the moisture content in EFB is around 67%, pre-processing is necessary before EFB can be considered as a good fuel.

In contrast to shells and fibers, empty fruit bunches are usually burnt causing air pollution or returned to the plantations as mulch. Empty fruit bunches can be conveniently collected and are available for exploitation in all Palm Oil mills. Since shells and fibres are easy-to-handle, high quality fuels compared to EFB, it will be advantageous to utilize EFB for on-site energy demand while making shells and fibres available for off-site utilization which may bring more revenues as compared to burning on-site.

Palm Oil Mill Effluent (POME)

Palm Oil processing also gives rise to highly polluting waste-water, known as Palm Oil Mill Effluent, which is often discarded in disposal ponds, resulting in the leaching of contaminants that pollute the groundwater and soil, and in the release of methane gas into the atmosphere. POME could be used for biogas production through anaerobic digestion. At many palm oil mills this process is already in place to meet water quality standards for industrial effluent. The gas, however, is flared off.

In a conventional Palm Oil mill, 600-700 kg of POME is generated for every ton of processed FFB. Anaerobic digestion is widely adopted in the industry as a primary treatment for POME. Liquid effluents from palm oil mills can be anaerobically converted into biogas which in turn can be used to generate power through gas turbines or gas-fired engines.

Conclusions

Most of the Biomass residues from Palm Oil Mills are either burnt in the open or disposed off in waste ponds. The Palm Oil industry, therefore, contributes significantly to global climate change by emitting carbon dioxide and methane. Like sugar mills, Palm Oil mills have traditionally been designed to cover their own energy needs (process heat and electricity) by utilizing low pressure boilers and back pressure turbo-generators. Efficient energy conversion technologies, especially thermal systems for crop residues, that can utilize all Palm Oil residues, including EFBs, are currently available.

In the Palm Oil value chain there is an overall surplus of by-products and their utilization rate is negligible, especially in the case of POME and EFBs. For other mill by-products the efficiency of the application can be increased. Presently, shells and fibers are used for in-house energy generation in mills but empty fruit bunches is either used for mulching or dumped recklessly. Palm Oil industry has the potential of generating large amounts of electricity for captive consumption as well as export of surplus power to the public grid.