Environmental Best Practices for MENA Cement Industry

Cement production in MENA region has almost tripled during the last 15 years, mainly on account of high population growth rate, rapid urbanization, increasing industrialization and large-scale infrastructural development. The growth of cement industry in MENA is marked by factors that are directly connected with sustainability, energy efficiency and raw material supply. Although the factors differ from country to country and cannot be generalized, there are major concerns regarding shortage of raw materials, GHG emissions, dependence on fossil fuels and lack of investment in technological innovations.

For the MENA cement sector, key points for an environment-friendly industry are use of alternative raw materials and alternative fuels, energy-efficient equipment and green technologies. As the use of alternative fuels and raw materials is still uncommon in the Middle East, guidelines and regulatory framework have to be defined which can set standards for the use of alternative or waste-derived fuels like municipal solid wastes, dried sewage sludge, agricultural wastes, drilling wastes etc.

Sewage Sludge

An attractive disposal method for sewage sludge is to use it as alternative fuel source in a cement kiln. Dried sewage sludge with high organic content possesses a high calorific value. Due to the high temperature in the kiln the organic content of the sewage sludge will be completely destroyed. The resultant ash is incorporated in the cement matrix. Infact, several European countries, like Germany and Switzerland, have already started adopting this practice for sewage sludge management.

The MENA region produces huge quantity of municipal wastewater which represents a serious problem due to its high treatment costs and risk to environment, human health and marine life. Sewage generation across the region is rising by an astonishing rate of 25 percent every year. Municipal wastewater treatment plants in MENA produce large amounts of sludge whose disposal is a cause of major concern.

For example, Kuwait has 6 wastewater treatment plants, with combined capacity of treating 12,000m³ of municipal wastewater per day, which produce around 250 tons of sludge daily. Similarly Tunisia has approximately 125 wastewater treatment plants which generate around 1 million tons of sewage sludge every year. Currently most of the sewage is sent to landfills. Sewage sludge generation is bound to increase at rapid rates in MENA due to increase in number and size of urban habitats and growing industrialization.

The use of sewage sludge as alternative fuel is a common practice in cement plants around the world, Europe in particular. It could be an attractive business proposition for wastewater treatment plant operators and cement industry in the Middle East to work together to tackle the problem of sewage sludge disposal, and high energy requirements and GHGs emissions from the cement industry.

Use of sludge in cement kilns will led to eco-friendly disposal of municipal sewage

Use of sludge in cement kilns will led to eco-friendly disposal of municipal sewage

Sewage sludge has relatively high net calorific value of 10-20 MJ/kg as well as lower carbon dioxide emissions factor compared to coal when treated in a cement kiln. Use of sludge in cement kilns can also tackle the problem of safe and eco-friendly disposal of sewage sludge. The cement industry accounts for almost 5 percent of anthropogenic CO2 emissions worldwide. Treating municipal wastes in cement kilns can reduce industry’s reliance on fossil fuels and decrease greenhouse gas emissions.

Municipal Solid Wastes and Biomass

Alternative fuels, such as refuse-derived fuels or RDF, have very good energy-saving potential. The substitution of fossil fuel by alternative sources of energy is common practice in the European cement industry. The German cement industry, for example, substitutes approximately 61% of their fossil fuel demand. Typical alternative fuels available in MENA countries are municipal solid wastes, agro-industrial wastes, industrial wastes and crop residues.

The gross urban waste generation quantity from Middle East countries has crossed 150 million tons per annum. Bahrain, Saudi Arabia, UAE, Qatar and Kuwait rank in the top-ten worldwide in terms of per capita solid waste generation. Solid waste disposal is a big challenge in almost all MENA countries so conversion of MSW to RDF will not ease the environmental situation but also provide an attractive fuel for the regional cement industry. Tens of millions of tyres are discarded across the MENA region each year. Scrap tyres are are an attractive source of energy and find widespread use in countries around the world.

Agriculture plays an important role in the economies of most of the countries in the Middle East and North Africa region.  Despite the fact that MENA is the most water-scarce and dry region in the world, many countries in the region, especially those around the Mediterranean Sea, are highly dependent on agriculture. Egypt is the 14th biggest rice producer in the world and the 8th biggest cotton producer in the world. Similarly Tunisia is one of the biggest producers and exporters of olive oil in the world. Such high biomass production rates should be welcomed by the cement industry since these materials comprise cotton stalks, rice husks and rice straw which serve ideally as alternative fuels. However it is ironical that olive kernels – the waste from Tunisian olive production – is exported to European power plants in order to save fossil fuel-derived CO2 emissions there, while Tunisia imports approximately 90% of its energy demand, consisting of fossil fuels.

Drilling Wastes as Alternative Raw Material

The reduction of clinker portion in cement affords another route to reduce energy consumption. In particular, granulated blast furnace slags or even limestone have proven themselves as substitutes in cement production, thus reducing the overall energy consumption. The Middle East oil and gas industry has made a lot of effort in order to reduce the environmental impact of their activities. The use of drilling wastes and muds is preferable in cement kilns, as a cement kiln can be an attractive, less expensive alternative to a rotary kiln. In cement kilns, drilling wastes with oily components can be used in a fuel-blending program to substitute for fuel that would otherwise be needed to fire the kiln.

Conclusions

The cement industry can play a significant role in the sustainable development in the Arab countries, e.g. by reducing fossil fuel emissions with the use of refused derived fuels (RDF) made from municipal solid waste or biomass pellets. The cement companies in the Middle East can contribute to sustainability also by improving their own internal practices such as improving energy efficiency and implementing recycling programs. Businesses can show commitments to sustainability through voluntary adopting the concepts of social and environmental responsibilities, implementing cleaner production practices, and accepting extended responsibilities for their products.  

The major points of consideration are types of wastes and alternative fuels that may be used, standards for production of waste-derived fuels, emission standards and control mechanisms, permitting procedures etc. Appropriate standards also need to be established for alternative raw materials that are to be used for clinker and cement production.

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Biomass Potential of Date Palm Wastes

Date palm is one of the principal agricultural products in the arid and semi-arid region of the world, especially Middle East and North Africa (MENA) region. There are more than 120 million date palm trees worldwide yielding several million tons of dates per year, apart from secondary products including palm midribs, leaves, stems, fronds and coir. The Arab world has more than 84 million date palm trees with the majority in Egypt, Iraq, Saudi Arabia, Iran, Algeria, Morocco, Tunisia and United Arab Emirates.

Egypt is the world’s largest date producer with annual production of 1.47 million tons of dates in 2012 which accounted for almost one-fifth of global production. Saudi Arabia has more than 23 millions date palm trees, which produce about 1 million tons of dates per year. Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits. Some studies have reported that Saudi Arabia alone generates more than 200,000 tons of date palm biomass each year.

Date palm is considered a renewable natural resource because it can be replaced in a relatively short period of time. It takes 4 to 8 years for date palms to bear fruit after planting, and 7 to 10 years to produce viable yields for commercial harvest. Usually date palm wastes are burned in farms or disposed in landfills which cause environmental pollution in date-producing nations. In countries like Iraq and Egypt, a small portion of palm biomass in used in making animal feed.

The major constituents of date palm biomass are cellulose, hemicelluloses and lignin. In addition, date palm has high volatile solids content and low moisture content. These factors make date palm biomass an excellent waste-to-energy resource in the MENA region. A wide range of thermal and biochemical technologies exists to convert the energy stored in date palm biomass to useful forms of energy. The low moisture content in date palm wastes makes it well-suited to thermo-chemical conversion technologies like combustion, gasification and pyrolysis.

On the other hand, the high volatile solids content in date palm biomass indicates its potential towards biogas production in anaerobic digestion plants, possibly by codigestion with sewage sludge, animal wastes and/and food wastes. The cellulosic content in date palm wastes can be transformed into biofuel (bioethanol) by making use of the fermentation process. Thus, abundance of date palm trees in the GCC, especially Saudi Arabia, can catalyze the development of biomass and biofuels sector in the region.

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Wastes as Energy Resource

The tremendous increase in the quantum and diversity of waste materials generated by human activities has focused the spotlight on waste management options. Waste generation rates are affected by standards of living, degree of industrialization and population density. Generally, the greater the economic prosperity and the higher percentage of urban population, the greater the amount of waste produced. A good example are the oil-rich GCC nations who are counted among the world's most prolific per capita waste generators.

Reduction in the volume and mass of wastes is a crucial issue due to limited availability of final disposal sites in the Middle East. There is, no doubt, an obvious need to reduce, reuse and recycle wastes but recovery of energy from wastes is also gaining ground as a vital method for managing wastes and Middle East should not be an exception.

Wastes can be transformed into clean and efficient energy and fuel by a variety of technologies, ranging from conventional combustion process to state-of-the-art plasma gasification technology. Besides recovery of energy, such technologies leads to substantial reduction in the overall waste quantities requiring final disposal. Waste-to-energy projects provide major business opportunities, environmental benefits, and energy security.  Feedstock for waste-to-energy plants can be obtained from a wide array of sources including municipal wastes, crop residues and agro-industrial wastes. 

Let us explore some of major waste resources that are readily available in Middle East and North Africa region:

Municipal Solid Wastes

Atleast 150 million tons of solid wastes are collected each year in the MENA region with the vast majority disposed of in open fields and dumpsites. The major energy resource in municipal solid waste is made up of food residuals, paper, fruits, vegetables, plastics etc which make up as much as 75 – 80 percent of the total MSW collected.

Municipal wastes can be converted into energy by thermochemical or biological technologies. At the landfill sites the gas produced by the natural decomposition of MSW (called landfill gas) can be collected, scrubbed and cleaned before feeding into internal combustion engines or gas turbines to generate heat and power. The organic fraction of MSW can be biochemically stabilized in an anaerobic digester to obtain biogas (for heat and power) as well as fertilizer. Sewage sludge is a big nuisance for municipalities and general public but it is a very good source of biogas, which can efficiency produced at sewage treatment plants.

Agricultural Residues

Crop residues encompasses all agricultural wastes such as bagasse, straw, stem, stalk, leaves, husk, shell, peel, pulp, stubble, etc. Large quantities of crop residues are produced annually in the MENA region, and are vastly underutilised. Wheat and barley are the major staple crops grown in the Middle East region. In addition, significant quantities of rice, maize, lentils, chickpeas, vegetables and fruits are produced throughout the region, mainly in Egypt, Tunisia, Saudi Arabia, Morocco and Jordan. 

Current farming practice is usually to plough these residues back into the soil, or they are burnt, left to decompose, or grazed by cattle. Agricultural residues are characterized by seasonal availability and have characteristics that differ from other solid fuels such as wood, charcoal, char briquette. Crop wastes can be used to produce biofuels, biogas as well as heat and power through a wide range of well-proven technologies.

Animal Wastes

The MENA countries have strong animal population. The livestock sector, in particular sheep, goats and camels, plays an important role in the national economy of respective countries. Many millions of live ruminants are imported 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. In the past, this waste was recovered and sold as a fertilizer or simply spread onto agricultural land, but the introduction of tighter environmental controls on odour and water pollution means that some form of waste management is now required, which provides further incentives for waste-to-energy conversion. The most attractive method of converting these waste materials to useful form is anaerobic digestion.

Wood Wastes

Wood processing industries primarily include sawmilling, plywood, wood panel, furniture, building component, flooring, particle board, moulding, jointing and craft industries. Wood wastes generally are concentrated at the processing factories, e.g. plywood mills and sawmills. In general, processing of 1,000 kg of wood in the furniture industries will lead to waste generation of almost half (45 %), i.e. 450 kg of wood.

Similarly, when processing 1,000 kg of wood in sawmill, the waste will amount to more than half (52 %), i.e. 520 kg wood. Wood wastes has high calorific value and can be efficiency converted into energy by thermal technologies like combustion and gasification.

Industrial Wastes

The food processing industry in MENA produces a large number of organic residues and by-products that can be used as biomass energy sources. These waste materials are generated from all sectors of the food industry with everything from meat production to confectionery producing waste that can be utilised as an energy source. In recent decades, the fast-growing food and beverage processing industry has remarkably increased in importance in major countries of the region.

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. Wastewater from food processing industries contains sugars, starches and other dissolved and solid organic matter. A huge potential exists for these industrial wastes to be biochemically digested to produce biogas, or fermented to produce ethanol, and several commercial examples of waste-to-energy conversion already exist around the world.

Conclusions

An environmentally sound and techno-economically viable methodology to treat wastes is highly crucial for the sustainability of modern societies. The MENA region is well-poised for waste-to-energy development, with its rich resources in the form of municipal solid waste, crop residues and agro-industrial waste. The implementation of advanced waste-to-energy conversion technologies as a method for safe disposal of solid and liquid wastes, and as an attractive option to generate heat, power and fuels, can greatly reduce environmental impacts of wastes in the Middle East. 

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Combined Heat and Power Systems

Combined Heat and Power (CHP), or Cogeneration, is the sequential or simultaneous generation of multiple forms of useful energy (usually mechanical and thermal) in a single, integrated system. In conventional electricity generation systems, about 35% of the energy potential contained in the fuel is converted on average into electricity, whilst the rest is lost as waste heat.

CHP systems uses both electricity and heat and therefore can achieve an efficiency of up to 90%, giving energy savings between 15-40% when compared with the separate production of electricity from conventional power stations and of heat from boilers.

CHP systems consist of a number of individual components—prime mover (heat engine), generator, heat recovery, and electrical interconnection—configured into an integrated whole. The type of equipment that drives the overall system (i.e., the prime mover) typically identifies the CHP unit. 

Prime movers for CHP units include reciprocating engines, combustion or gas turbines, steam turbines, microturbines, and fuel cells. These prime movers are capable of burning a variety of fuels, including natural gas, coal, oil, and alternative fuels to produce shaft power or mechanical energy.

CHP Technology Options

Reciprocating or internal combustion engines (ICEs) are among the most widely used prime movers to power small electricity generators. Advantages include large variations in the size range available, fast start-up, good efficiencies under partial load efficiency, reliability, and long life.

Steam turbines are the most commonly employed prime movers for large power outputs. Steam at lower pressure is extracted from the steam turbine and used directly or is converted to other forms of thermal energy. System efficiencies can vary between 15 and 35% depending on the steam parameters.

Co-firing of biomass with coal and other fossil fuels can provide a short-term, low-risk, low-cost option for producing renewable energy while simultaneously reducing dependence on fossil fuels. Biomass can typically provide between 3 and 15 percent of the input energy into the power plant. Most forms of biomass are suitable for co-firing. 

Steam engines are also proven technology but suited mainly for constant speed operation in industrial environments. Steam engines are available in different sizes ranging from a few kW to more than 1 MWe.

A gas turbine system requires landfill gas, biogas, or a biomass gasifier to produce the gas for the turbine. This biogas must be carefully filtered of particulate matter to avoid damaging the blades of the gas turbine.  

Stirling engines utilize any source of heat provided that it is of sufficiently high temperature. A wide variety of heat sources can be used but the Stirling engine is particularly well-suited to biomass fuels. Stirling engines are available in the 0.5 to 150 kWe range and a number of companies are working on its further development.

A micro-turbine recovers part of the exhaust heat for preheating the combustion air and hence increases overall efficiency to around 20-30%. Several competing manufacturers are developing units in the 25-250kWe range. Advantages of micro-turbines include compact and light weight design, a fairly wide size range due to modularity, and low noise levels. 

Saudi ARAMCO's CHP Initiatives

Recently ARAMCO announced the signing of agreements to build and operate cogeneration plants at three major oil and gas complexes in Saudi Arabia. These agreements demonstrate ARAMCO's commitment to pursue energy efficiency in its operation. Upon completion, the cogeneration plants will meet power and heating requirements at Abqaiq, Hawiya and Ras Tanura plants. These plants are expected to generate a total on 900MW of power and 1,500 tons of steam per hour when they come onstream in 2016.

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Jatropha’s Relevance for MENA

Jatropha is a genus of nearly 175 species of shrubs, low-growing plants, and trees.  However, discussions of Jatropha as a biodiesel are actually means a particular species of the plant, Jatropha curcas. The plant is indigenous to parts of Central America, however it has spread to other tropical and subtropical regions in Africa and Asia.

Jatropha curcas is a perennial shrub that, on average, grows approximately three to five meters in height. It has smooth grey bark with large and pale green leaves. The plant produces flowers and fruits are produced in winter or throughout the year depending on temperature and soil moisture. The curcas fruit contains 37.5 percent shell and 62.5 percent seed.  Jatropha curcas can be grown from either seed or cutting.

By virtue of being a member of the Euphorbiaceae family, Jatropha has a high adaptability for thriving under a wide range of physiographic and climatic conditions. It is found to grow in all most all parts of the country up to an elevation 3000 feet. Jatropha is suitable for all soils including degraded and barren lands, and is a perennial occupying limited space and highly suitable for intercropping.

Extensive research has shown that Jatropha requires low water and fertilizer for cultivation, is not grazed by cattle or sheep, is pest resistant, is easily propagated, has a low gestation period, and has a high seed yield and oil content, and produces high protein manure. Sewage effluents provide a good source of water and nutrients for cultivating Jatropha, though there are some risk of salinization in arid regions.

Pongamia pinnata or Karanj is another promising non-edible oil seed plant that can be utilized for oil extraction for biofuels. The plant is a native of India and grows in dry places far in the interior and up to an elevation of 1000 meters. Pongamia plantation is not much known as like Jatropha, but the cost effectiveness of this plant makes it more preferred than other feedstock. Pongamia requires about four to five times lesser inputs and giver two to three times more yield than Jatropha which makes it quite suitable for small farmers. However, Pongamia seeds have about 5-10 percent less oil content than Jatropha and the plant requires longer period to grow as the gestation period is about 6-8 years for Pongamia against 3-5 years in Jatropha

To conclude, Jatropha can be successfully grown in arid regions of the Middle East and North Africa (MENA) for biodiesel production. These energy crops are highly useful in preventing soil erosion and shifting of sand-dunes. The production of sewage-irrigated energy crops has good potential to secure additional water treatment and thus reduce adverse environmental impacts of sewage disposal. Countries in the Middle East, like Eqypt, Libya, Sudan, Jordan and Saudi Arabia, are well-suited to the growth of Jatropha plantations. Infact, Jatropha is already grown at limited scale in some Middle East countries, especially Egypt,  and tremendous potential exists for its commercial exploitation.

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Biomass Energy in Jordan

Jordan has promising biomass energy potential in the form of municipal solid wastes, crop residues and organic industrial wastes.  Municipal solid wastes represent the best source of biomass in Jordan. In terms of quantity per capita and constituents, the waste generated in Jordan is comparable to most semi-industrialized nations. Agricultural biomass offers a low energy potential due to arid climate in most of the country.

The major biomass energy resources in Jordan are:

  • Municipal waste from big cities
  • Organic wastes from slaughterhouse, vegetable market, hotels and restaurants.
  • Organic waste from agro-industries
  • Animal manure, mainly from cows and chickens.
  • Sewage sludge and septic.
  • Olive mills.
  • Organic industrial waste

The total generation of municipal waste in Jordan is estimated at more than 2 million tons per year. In addition, an annual amount of 1.83 million cubic meter of septic and sewage sludge from treatment of 44 million cubic meter of sewage water is generated in Greater Amman area. The potential annual sewage sludge and septic generated in Amman can be estimated at 85,000 tons of dry matter. Jordan also generate significant amount of animal manure due to strong animal population in the form of cattle, sheep, camels, horses etc. 

Organic industrial wastes, either liquid or solid, is a good biomass resource and can be a good substrate for biogas generation. Anaerobic digestion is fast gaining popularity as one of the best waste management method for biomass utilization. The use of anaerobic digestion technology for biomassl waste management would be a significant step in Jordan’s emergence as a renewable energy hub in the MENA region. Jordan is planning to implement 40-50 MW of waste-to-energy projects by 2020.

Biogas Plant at Rusaifeh Landfill

The Government of Jordan, in collaboration with UNDP, GEF and the Danish Government, established 1MW biogas plant at Rusaifeh landfill near Amman in 1999.  The plant has been successfully operating since its commissioning and has recently been increased to 4MW. The project consists of a system of twelve landfill gas wells and an anaerobic digestion plant based on 60 tons per day of organic wastes from hotels, restaurants and slaughterhouses in Amman. The successful installation of the biogas project has made it a role model in the entire region and several big cities are striving to replicate the model.

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Role of Agricultural Sector in Harnessing Renewable Energy

The continuous rise in fossil energy prices, combined with climate change concerns and progress in renewable energy sector, has catalyzed interest in clean energy systems across the MENA region, especially in the Mediterranean. The Mediterranean region has abundant renewable resources, such as wind, solar, and biomass, which makes it a fertile zone for renewable energy developments. 

The agricultural sector has played a key role in the progress of renewable energy sector around the world as it provides large areas where renewable energy projects are built and is also the predominant feedstock source for biomass energy projects. For example, German agricultural sector accounts for one-fifth of the total installed PV capacity.

The main objective of this article is to explore the role that Mediterranean agricultural sector can play in tapping tremendous renewable energy potential available across the region.

Wind Energy

In countries where there is a lack of available land to build wind turbines, the agricultural sector is playing a key role by providing enough spaces. For instance, in Denmark farmer cooperatives are diversifying their incomes by investing in wind energy. Almost a quarter of wind energy sourced from wind turbines are owned by the Danish farmers. The same trend is taking place in Germany where farmers have established private companies to develop wind energy projects. Wind farms can be built in farms without any harmful impact on agricultural activities.

Wind energy potential is abundant across the Mediterranean region due to geographical location marked by a long coastline. The integration of wind energy projects in the agricultural sector is an interesting economic opportunity for agricultural enterprises in the region. However, as wind energy projects demand heavy capital, there is a need to mobilize funds to develop such projects.

In addition, there is need to create attractive financing mechanisms for farmers and to build their capacities in developing and managing wind projects. The development of wind energy projects owned by farmers will help them to have an extra revenue stream. It will also lead to decentralization of electricity production, which will not only reduce transmission losses but also decrease reliance on the national grid.

Solar Energy

The Mediterranean region receives one of the highest solar radiation in the world. Large availability of unexploited lands in the region, especially in the Eastern and Southern countries, makes solar energy systems, especially photovoltaics an attractive proposition for regional countries.  Agricultural farms in the Mediterranean region can use PV systems for domestic as well as commercial power generation.  In addition, there are a handful of applications in agricultural sector such as water pumping and irrigation.

Off-grid photovoltaic systems ensure a reliable and completely autonomous water supply at low cost – without fuel-powered generators, battery systems or long power lines. Solar energy can make irrigation independent of grid power. Low-pressure drip irrigation systems can be operated with any photovoltaic-powered pump, making them ideal for areas not connected to the grid. Photovoltaic projects require low capital investment and can be developed at small-to-medium scales.

Bioenergy

A variety of fuels can be produced from agricultural biomass resources including liquid fuels, such as ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and gaseous fuels, such as hydrogen and methane. The agricultural resources include animal manure and crop residues derived primarily from maize, corn and small grains. A variety of regionally significant crops, such as cotton, sugarcane, rice, and fruit and nut orchards can also be a source of crop residues.

Globally, biofuels are most commonly used to power vehicles, heat homes, and for cooking. Biofuels are generally considered as offering many priorities, including sustainability, reduction of greenhouse gas emissions, regional development, social structure and agriculture, and security of supply.        

One of the species that is cultivated and exploited for these purposes is Jatropha curcas which is widely cultivated in Brazil and India for producing biodiesel. Jatropha can be successfully grown in arid regions of the Mediterranean for biodiesel production. These energy crops are highly useful in preventing soil erosion and shifting of sand-dunes. Infact, Jatropha is already grown at limited scale in some Middle East countries, especially Egypt,  and tremendous potential exists for its commercial exploitation.

Conclusion

The time has come for industries in the Mediterranean region, especially the agricultural sector, to undertake the shift necessary to contribute to sustainable development of the MENA region by making the best use of latest technological developments in renewable energy sector.

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African Development Bank and Renewable Energy

Africa has huge renewable energy potential with some of the world’s largest concentration of alternative energy resources in the form of solar, wind, hydro, and energy. Overall, 17 countries in sub-Saharan Africa are in the top-33 countries worldwide with combined reserves of solar, wind, hydro, and geothermal energy far exceeding annual consumption. Most of the sub-Saharan countries receive solar radiation in the range of 6-8 kWh/m2/day, which counts among the highest amounts of solar radiation in the world. Until now, only a small fraction of Africa’s vast renewable energy potential has been tapped.  The renewable energy resources have the potential to cover the energy requirements of the entire continent.

The African Development Bank has supported its member countries in their energy development initiatives for more than four decades. With growing concerns about climate change, AfDB has compiled a strong project pipeline comprised of small- to large-scale wind-power projects, mini, small and large hydro-power projects, cogeneration power projects, geothermal power projects and biodiesel projects. The major priorities for the Bank include broadening the supply of low-cost environmentally clean energy and developing renewable forms of energy to diversify power generation sources in Africa. The AfDB’s interventions to support climate change mitigation in Africa are driven by sound policies and strategies and through its financing initiatives the Bank endeavors to become a major force in clean energy development in Africa.

Energy projects are an important area of the AfDB’s infrastructure work, keeping in view the lack of access to energy services across Africa and continued high oil prices affecting oil-importing countries. AfDB’s Programme for Infrastructure Development in Africa (PIDA), and other programmes, are in the process of identifying priority investment projects in renewable energy, which also include small and medium scale hydro and biomass co-generation.  The Bank supports its member countries towards developing renewable energy projects in three ways:

  • By encouraging countries to mainstream clean energy options into national development plans and energy planning.
  • By promoting investment in clean energy and energy efficiency ventures
  • By supporting the sustainable exploitation of the huge energy potential of the continent, while supporting the growth of a low-carbon economy.

FINESSE Africa Program

The FINESSE Africa Program, financed by the Dutch Government, has been the mainstay of AfDB’s support of renewable energy and energy efficiency since 2004. The Private Sector department of AfDB, in collaboration with the Danish Renewable Energy Agency (DANIDA), has developed a robust project pipeline of solar, wind, geothermal and biomass energy projects for upcoming five years. 

The FINESSE program has helped in project preparation/development for Lesotho (rural electrification by means of different sources of renewable energy), Madagascar (rural water supply using solar water pumps), Ghana (energy sector review) and Uganda (solar PV for schools and boarding facilities), as well as on the development of the energy component of the Community Agricultural Infrastructure Improvement Program in Uganda (solar PV, hydropower and grid extension), the Bank’s initiative on bio-ethanol in Mozambique (including co-funding a recent bio fuels workshop in Maputo) and the AfDB Country Strategy Paper revision in Madagascar.

Clean Energy Investment Framework

The AfDB’s Clean Energy Investment Framework aims at promoting sustainable development and contributing to global emissions reduction efforts by using a three-pronged approach: maximize clean energy options, emphasize energy efficiency and enable African countries to participate effectively in CDM sector. The AfDB’s interventions to support climate change mitigation in Africa are driven by sound policies and strategies and through its financing initiatives the Bank endeavors to become a major force in clean energy development in Africa.

In order to finance energy access and clean energy development operations, the Bank Group will draw on resources from its AfDB non-concessional window to finance public-sponsored projects and programs in countries across Africa. According to the Framework, AfDB will work with a range of stakeholders (national governments, regional organizations, sub-sovereign entities, energy and power utilities, independent power producers and distributors, sector regulators, and civil society organizations) on key issues in clean energy access and climate adaptation in all regional member countries. 

Climate Investment Funds

Part of the AfDB’s commitment to supporting Africa’s move toward climate resilience and low carbon development is expanding access to international climate change financing. The African Development Bank is implementing the Climate Investment Funds (CIF), a pair of funds designed to help developing countries pilot transformations in clean technology, sustainable management of forests, increased energy access through renewable energy, and climate-resilient development. The AfDB has been involved with the CIF since their inception in 2008. 

The Bank is actively supporting African nations and regions as they develop CIF investment plans and then channeling CIF funds, as well as its own co-financing, to turn those plans into action. One of the Climate Investment Funds, the Clean Technology Fund (CTF) provides developing countries with positive incentives to scale up the demonstration, deployment, and transfer of technologies with a high potential for long-term greenhouse gas (GHG) emissions savings. 

In the Middle East and North Africa region, US$750 million in CTF funding is supporting deployment of 1GW of solar power generation capacity, reducing about 1.7 million tons of CO2 per year from the energy sectors of Algeria, Egypt, Jordan, Morocco and Tunisia. In Morocco, US$197 million in CTF funding is cofinancing the world’s largest concentrated solar power initiative. Another US$125 million is helping scale up investments in its wind energy program targeting 2GW by 2020.

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Polylactic Acid – An Emerging Bioplastic

During the last decade, the movement towards biobased products has increased dramatically as a result of increasing environment awareness and high increase in fossil fuel prices. Polylactic Acid (PLA) is an eco-friendly polymer derived from lactic acid which can be produced by fermentation of renewable resources. It is a new type of biocompatible material produced from utilizing lactic acid as monomer. Since lactic acid is a non-toxic component, which exists in human metabolism, PLA is safe polyester for human-related applications.

In comparison to traditional plastics, PLA has great potential in the plastic market. Petroleum-based plastic takes hundreds of year to biologically degrade and is manufactured from non-renewable resources. PLA, on the other hand, is recyclable, produced by less energy-intensive process and compostable. Infact, it is a polymer which can be naturally converted to carbon dioxide and water within few years.

Feedstock Selection

Many raw materials could be utilised to produce lactic acid such as, starch, lignocellulosic biomass, agro-industrial wastes, glycerol and microalgae. In order to choose the most suitable biomass for an efficient process, the raw material should have the following characteristic.

  • As cheap as possible to make the maximum profit from the project
  • Low level of contaminants which means less cost on pre-treatment of the biomass to purify the main substrate. 
  • Rapid production rate, more harvested product should be obtained per annum.
  • High yield with less by-products formation.
  • Continuous production rate along the year to minimise the raw material storage.

It seems impossible to have 100% ideal raw material so a trade-off decision must be made. Moreover, the combination of more than one raw material is even possible if the second one is given for free, for example, provided that the chosen microorganism can convert both raw materials to lactic acid without an extra cost. Production of lactic acid from waste has been studied by many researchers. However, the two promising materials are paper waste and glycerol. Moreover, potato and corn starch effluent have been used as a free raw materials for lactic acid production.

Glycerol is the main by-product of the biodiesel process therefore it would be a really cheap feedstock to be used in the production of fuel and chemicals. Ten percent of the total biodiesel production is by-product crude glycerol which could have a negative effect on the environment to be disposed. Production of chemical from this by product could minimise the price of the biodiesel as it is produced at a relatively large quantity.

Office automation paper could be pre-treated and then converted to lactic acid by a specific microorganism. Different types of pulp, hemicellulose, and toner or ink-related compounds can reduce the production rate of lactic acid.

Undoubtedly, the best carbon source for most microorganisms is glucose which could be easily utilized in large scale lactic acid production. The second preferred carbon sources are starch and lignocellulose materials which have been recognized as a cost effective raw material. However, it is more difficult to ferment lignocellulosic biomass than starchy ones to lactic acid. This is because lignocellulosic biomass has cellulose as the polymer which requires physic-chemical pretreatment and multi-enzymatic reactions.

Microorganism Selection

In general, microbial lactic acid is mainly produced by two types of microorganisms which are bacteria and fungi. The enantiomers, yields and concentration of lactic acid depend on the type and the strain of microorganism. Each microorganism requires specific raw material to be utilised to give specific productivity in the optimum culture conditions.

Applications

PLA finds wide applications due to its unique properties. PLA is being used for food packaging, automobiles, textiles, foams, films etc in Europe, North America and the Asia-Pacific. Europe is the dominant market for biodegradable polymers, accounting for more than half of the world consumption.  The key market drivers in Europe include a packaging waste directive to set recovering and recycling targets, a number of plastic bag bans, and other collection and waste disposal laws to avoid landfill. As far as Middle East is concerned, use of PLA or other bioplastics is in nascent stages and its current penetration is very negligible.

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Algae Biorefinery – Promise and Potential

High oil prices, competing demands between foods and other biofuel sources, and the world food crisis, have ignited interest in algaculture (farming of algae) for making vegetable oil, biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels. Algae can be efficienctly grown on land that is not suitable for agriculture and hold huge potential to provide a non-food, high-yield source of biodiesel, ethanol and hydrogen fuels. 

Several recent studies have pointed out that biofuel from microalgae has the potential to become a renewable, cost-effective alternative for fossil fuel with reduced impact on the environment and the world supply of staple foods, such as wheat, maize and sugar.

What are Algae?

Algae are unicellular microorganisms, capable of photosynthesis. They are one of the world’s oldest forms of life, and it is strongly believed that fossil oil was largely formed by ancient microalgae. Microalgae (or microscopic algae) are considered as a potential oleo-feedstock, as they produce lipids through photosynthesis, i.e. using only carbon , water, sunlight, phosphates, nitrates and other (oligo) elements that can be found in residual waters. Oils produced by diverse algae strains range in composition. For the most part are like vegetable oils, though some are chemically similar to the hydrocarbons in petroleum.

Advantages of Algae

Apart from lipids, algae also produce proteins, isoprenoids and polysaccharides. Some strains of algae ferment sugars to produce alcohols, under the right growing conditions. Their biomass can be processed to different sorts of chemicals and polymers (Polysaccharides, enzymes, pigments and minerals), biofuels (e.g. biodiesel, alkanes and alcohols), food and animal feed (PUFA, vitamins, etc.) as well as bioactive compounds (antibiotics, antioxidant and metabolites) through down-processing technology such as transesterification, pyrolysis and continuous catalysis using microspheres.

Algae can be grown on non-arable land (including deserts), most of them do not require fresh water, and their nutritional value is high. Extensive R&D underway on algae as raw material worldwide, especially in North America and Europe with a high number of start-up companies developing different options.

Most scientific literature suggests an oil production potential of around 25-50 ton per hectare per year for relevant algae species. Microalgae contain, amongst other biochemical, neutral lipids (tri-, di-, monoglycerides free fatty acids), polar lipids (glycolipids, phospholipids), wax esters, sterols and pigments. The total lipid content in microalgae varies from 1 to 90 % of dry weight, depending on species, strain and growth conditions.

Algae-based Biorefinery

In order to develop a more sustainable and economically feasible process, all biomass components (e.g. proteins, lipids, carbohydrates) should be used and therefore biorefining of microalgae is very important for the selective separation and use of the functional biomass components.

The term biorefinery was coined to describe the production of a wide range of chemicals and bio-fuels from biomasses by the integration of bio-processing and appropriate low environmental impact chemical technologies in a cost-effective and environmentally sustainable. If biorefining of microalgae is applied, lipids should be fractionated into lipids for biodiesel, lipids as a feedstock for the chemical industry and essential fatty acids, proteins and carbohydrates for food, feed and bulk chemicals, and the oxygen produced should be recovered also.

The potential for commercial algae production is expected to come from growth in translucent tubes or containers called photo bioreactors or in open systems (e.g. raceways) particularly for industrial mass cultivation or more recently through a hybrid approach combining closed-system precultivation with a subsequent open-system. Major advantages of a algal biorefinery include:

  • Use of industrial refusals as inputs ( CO2,wastewater and desalination plant rejects)
  • Large product basket with energy-derived (biodiesel, methane, ethanol and hydrogen) and non-energy derived (nutraceutical, fertilizers, animal feed and other bulk chemicals) products.
  • Not competing with food production (non-arable land and no freshwater requirements)
  • Better growth yield and lipid content than crops.

Indeed, after oil extraction the resulting algal biomass can be processed into ethanol, methane, livestock feed, used as organic fertilizer due to its high N:P ratio, or simply burned for energy cogeneration (electricity and heat). If, in addition, production of algae is done on residual nutrient feedstocks and CO2, and production of microalgae is done on large scale in order to lower production costs, production of bulk chemicals and fuels from microalgae will become economically, environmentally and ethically extremely attractive.

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موارد الطاقة الحيوية في منطقة الشرق الأوسط وشمال أفريقيا

 

اقتضى الارتفاع الملحوظ الذي شهدته أسعار النفط في الماضي القريب، والاضطرابات التي نجمت عنه في سوق الطاقة، من العديد من بلدان منطقة الشرق الأوسط وشمال أفريقيا لاسيما غير المنتجة للنفط منها، البحث عن مصادر جديدة للطاقة لأسباب اقتصادية وبيئية معاً. ومن جهة أخرى، باتت الطاقة المتجددة تحظى باهتمام عالمي متزايد، نظراً لدورها في الحد من التغيرات المناخية، ودفع عجلة التنمية المستدامة في البلدان النامية، وتعزيز أمن وتوفير الطاقة.

وتضم قائمة البلدان المنتجة للمخلفات العضوية في الشرق الأوسط وأفريقيا، كلاً من السودان، ومصر، والجزائر، واليمن، والعراق، وسوريا، والأردن، حيث اعتادت المناطق الريفية في هذه المنطقة استخدام الطاقة الحيوية بشكل واسع في الاستخدامات المنزلية. ونظراً لكون معظم أجزاء المنطقة تتمتع بمناخ جاف/ شبه جاف، فإن موارد الطاقة الحيوية المحتملة تأتي بشكل أساسي من المخلفات الصلبة في المدن، والفضلات الزراعية، والمخلفات الزراعية الصناعية.

والمخلفات العضوية هي تلك الناتجة عن النباتات التي تعتمد على أشعة الشمس في نموها، إضافة إلى مخلفات الحيوانات، والبقايا الناجمة عن الأنشطة الزراعية والحراجية، والصناعات العضوية والمخلفات البشرية والحيوانية. وفي حال ترك هذه المواد وسط عوامل البيئة الطبيعية، فإنها تتحلل خلال فترة طويلة من الزمن، لينطلق منها غاز ثاني أكسيد الكربون ومخزون الطاقة الذي تحتويه ببطء، على عكس عملية الحرق التي تؤدي إلى إطلاق مخزون الطاقة بسرعة وبطريقة مفيدة

غالباً، حيث أن تحويل هذه المخلفات إلى طاقة مفيدة يحاكي عملية التحلل الطبيعية، ولكنه أسرع منها وأكثر فائدة.

تقنيات تحويل المخلفات العضوية

هناك طيف واسع من التقنيات التي من شأنها أن تحقق إمكانية تحويل النفايات العضوية إلى مصدر للطاقة، وتتنوع بين الأنظمة البسيطة للتخلص من النفايات الجافة، والتقنيات الأكثر تعقيداً لمعالجة الكميات الكبيرة من النفايات الصناعية. وبالإمكان تحويل المخلفات العضوية إلى طاقة عبر عملية احتراق بسيطة، حيث يتم حرقها مع أنواع الوقود الأخرى، أو من خلال عملية وسيطة مثل التحويل إلى غاز. ويمكن استخدام الطاقة الناتجة كمصدر للكهرباء أو الحرارة، أو كلاهما معاً. ومن أهم مزايا استخدام الحرارة كمصدر أو بديل للطاقة الكهربائية، التطور الملموس في كفاءة التحويل، حيث أن توليد الطاقة يوفر كفاءة قياسية تقارب 30%، بينما يوفر استخدام الحرارة كفاءة تتجاوز 85%.

ويمكن للعمليات الكيميائية الحيوية، مثل المعالجة الفراغية، أن تنتج أيضاً طاقة نظيفة على شكل غاز حيوي قابل للتحويل إلى طاقة وحرارة باستخدام محرك يعمل بالغاز. وبالإضافة إلى ذلك، يمكن إنتاج الوقود السائل من النفايات، مثل "الايثانول السليلوزي" و "الديزل الحيوي"، والتي يمكن الاستعاضة بها عن الوقود المشتق من البترول. وتبرز حالياً نفايات الأشنيات (الطحالب) العضوية كمصدر جيد للطاقة، حيث أنها تعد بمثابة مصدر طبيعي للزيوت، والتي يمكن للمصافي التقليدية تحويله إلى وقود للطائرات أو وقود الديزل.

وتعكس وفرة وتنوع الخيارات التقنية لتحويل المخلفات العضوية، قابلية تطبيقها على نطاق محلي ضيق من أجل توفير الحرارة بشكل أساسي، أو استخدامها على نطاق أوسع لتوليد الطاقة والحرارة في وقت معاً. وبالتالي، يمكن تصميم عملية توليد الطاقة الحيوية بشكل يناسب المجتمعات الريفية أو المدنية، والاستفادة منها في التطبيقات الصناعية المحلية أو التجارية.

أصناف النفايات العضوية الرئيسية

توفر مشاريع الطاقة الحيوية فرصاً متميزة للأعمال، والعديد من المنافع البيئية، وتلعب دوراً كبيراً في تنمية الأرياف، حيث يمكن الحصول على المواد الحيوية الخام من مجموعة واسعة من الموارد، دون تعريض الطعام وموارد التغذية والغابات والتنوع الحيوي في العالم إلى الخطر.

النفايات البلدية الصلبة

تمثل النفايات البلدية الصلبة أفضل مصدر للمواد العضوية في بلدان منطقة الشرق الأوسط وشمال أفريقيا، حيث أن معدلات النمو السكاني المرتفعة، والعمران والتوسع الاقتصادي في المنطقة باتت تسرّع من معدلات الاستهلاك وطرح المخلفات العضوية في الوقت نفسه. وتصنف البحرين والسعودية والإمارات وقطر والكويت من ضمن البلدان العشرة الأولى في معدل إنتاج النفايات للفرد الواحد، حيث يقدر إنتاج البلدان العربية من النفايات بأكثر من 80 مليون طن سنوياً. وتعد المكبات المفتوحة أكثر طريقة سائدة في التخلص من النفايات البلدية الصلبة في معظم البلدان.

وتحتوي هذه النفايات على نسبة عالية نسبياً من المواد العضوية، في حين يعد الورق والزجاج والبلاستيك والمعادن مواداً أقل عضوية. وتمثل العناصر العضوية مصدراً لمواد التسميد المستخدمة في تحسين خصائص التربة، ويمكن استخدامها أيضاً لتوليد الكهرباء من غاز الميثان في حال تم فرزها وتكريرها بشكل صحيح، كما يمكن تحويل النفايات الصلبة إلى طاقة ووقود بواسطة التقنيات الحرارية المتطورة، مثل التسييل إلى غاز والتحليل بالحرارة. وفي واقع الأمر، تحظى تقنية استرجاع الطاقة من هذه النفايات بتقدير متزايد حول العالم، بوصفها التقنية الرابعة في نظام إدارة النفايات المستدام المؤلف من: إعادة الاستخدام، تقليص الكمية، التكرير، والاستعادة.

البقايا الزراعية

تلعب الزراعة دوراً هاماً في اقتصادات معظم بلدان منطقة الشرق الأوسط وشمال أفريقيا، حيث تتفاوت نسبة مساهمة قطاع الزراعة في الاقتصاد الإجمالي بين بلد وآخر، فعلى سبيل المثال تساهم الزراعة في اقتصاد الأردن بنسبة 3%، بينما ترتفع إلى 66% في الصومال. وتشهد عمليات الري الواسعة انتشاراً ملحوظاً في المنطقة، مما يتيح إنتاجاً وفيراً من المحاصيل عالية القيمة النقدية والتصديرية، بما فيها الفواكه والخضار والحبوب والسكر.

وتشتمل بقايا المحاصيل على كافة المخلفات الزراعية مثل البقاس، والقش، والساق والأوراق، والقشور، والغلاف، واللب، وجذامة النبات. ويعد القمح محصولاً رئيسياً مستقراً في منطقة الشرق الأوسط وشمال أفريقيا، ويتم سنوياً إنتاج كميات كبيرة من بقايا المحاصيل سنوياً، بيد أنه لا يتم الانتفاع منها بشكل حقيقي، حيث أن طرق الزراعة الحالية تعمد عادة إلى حرث هذه البقايا مع التربة، أو حرقها، أو تركها لتتحلل، أو علفاً للمواشي. ويمكن تحويل هذه البقايا إلى وقود سائل أو معالجتها حرارياً لتوليد الطاقة والحرارة في المناطق الريفية.

ويمكن زراعة محاصيل توليد الطاقة مثل أشجار "جاتروفا" في المناطق الجافة للحصول على الديزل الحيوي. وتزرع هذه الأشجار حالياً على نطاق محدود في بلدان منطقة الشرق الأوسط وشمال أفريقيا التي توفر فرصة هائلة يجدر استغلالها من أجل الاستثمار التجاري لهذه المحاصيل الهامة.

النفايات الصناعية

ينتج قطاع الأغذية في منطقة الشرق الأوسط وشمال أفريقيا كميات كبيرة من المخلفات العضوية والمنتجات التي يمكن استخدامها كمصادر للطاقة الحيوية. وخلال العقود الأخيرة، ازدادت أهمية قطاع معالجة الأغذية والمشروبات متسارع النمو، بشكل ملحوظ في البلدان الكبرى بمنطقة الشرق الأوسط وشمال أفريقيا. ومنذ أوائل التسعينات، ساهم الإنتاج الزراعي المتزايد في تشجيع عمليات تعليب الفواكه والخضراوات والعصائر والخضراوات، ومعالجة الزيت في دول مثل  مصر وسوريا والمغرب وتونس ولبنان والمملكة العربية السعودية. وهناك العديد من مصانع إنتاج مشتقات الحليب، والخبز، ومعالجة الزيوت، المتقدمة تكنولوجياً في المنطقة.

وتشمل النفايات الصلبة القشور وبقايا الخضراوات والفواكه، والمواد الغذائية التي لا تستوفي معايير مراقبة الجودة، ولب الورق، ولب وألياف قصب السكر والنشا المستخرج، والحمأة الناتجة عن المرشحات، ورواسب القهوة. وتنشأ النفايات السائلة نتيجة غسل اللحوم والفواكه والخضراوات، وتبييض الفواكه والخضراوات، وعمليات تنظيف وتجهيز اللحوم والدواجن والأسماك قبل طهيها، إضافة إلى عمليات صنع النبيذ.   

ومن الممكن إجراء عملية هضم لا هوائي لهذه النفايات الصناعية وإنتاج الغاز الحيوي، أو تخميرها لإنتاج الإيثانول، وهناك العديد من الأمثلة التجارية على عمليات تحويل النفايات إلى طاقة.

   
مخلفات الحيوانات    

هناك طائفة واسعة من النفايات الحيوانية التي يمكن استخدامها كمصادر لطاقة الكتلة الحيوية. ويعتبر سماد مخلفات الحيوانات والدواجن، أحد المصادر الأكثر شيوعا. ويتمثل الأسلوب الأكثر جاذبية لتحويل هذه النفايات إلى شكل مفيد، في عملية الهضم اللاهوائي التي ينتج عنها الغاز الحيوي، والذي يمكن استخدامه كوقود لمحركات الاحتراق الداخلي، وتوليد الكهرباء من توربينات الغاز الصغيرة، وحرقه مباشرة لأغراض الطهي، أو التدفئة، وتسخين المياه.

تتمتع دول الشرق الأوسط بثروة حيوانية كبيرة. ويلعب قطاع الماشية، خاصة الأغنام والماعز، دوراً هاماً في الاقتصاد الوطني لدول منطقة الشرق الأوسط وشمال أفريقيا. وتستورد دول المنطقة سنوياً ملايين الحيوانات المجترة الحية من مختلف أنحاء العالم. ويمكن تسخير إمكانية تحويل روث الحيوانات إلى غاز حيوي، وعلى نطاق المجتمع.   

مخلفات الغابات

تتميز منطقة الشرق الأوسط بندرة الغابات والتي تشكل ما يزيد على 5 ٪ تقريباً من اليابسة. وتنشأ مخلفات الغابات نتيجة عمليات خف النباتات وقطع الأشجار لشق طرق نقل الأخشاب، واستخراج جذوع الأشجار للحصول على اللب والأخشاب، إلى جانب تناقص الأشجار نتيجة الظروف الطبيعية. وعادة ما تكون كثافة مخلفات الغابات منخفضة، كما أن الوقود الناتج عنها يكون منخفض القيمة، الأمر الذي يحافظ على ارتفاع تكاليف النقل، وبالتالي فإنه من المجدي اقتصادياً التخفيف من كثافة الكتلة الحيوية في الغابة نفسها.

   
الخاتمة  

منطقة الشرق الأوسط وشمال أفريقيا على أهبة الاستعداد لتطوير طاقة الكتلة الحيوية، بفضل ما لديها من موارد الكتلة الحيوية على شكل مخلفات بلدية صلبة، ومخلفات المحاصيل الزراعية، والمخلفات الصناعية والزراعية. وقد ساهم تطبيق تقنيات متقدمة في مجال تحويل النفايات إلى طاقة، كوسيلة من وسائل التخلص الآمن من نفايات الكتلة الحيوية الصلبة والسائلة، وبوصفها خيارا جذابا لتوليد الحرارة والكهرباء والوقود، بشكل كبير في تخفيض الآثار البيئية التي تسببها مجموعة واسعة من النفايات. ويعتبر الانتقال من نظم الطاقة التقليدية إلى نظم تقوم على الموارد المتجددة، أمراً ضرورياً لتلبية الطلب المتزايد باستمرار على الطاقة، ومعالجة القضايا البيئية، وتعزيز التنمية المستدامة.

 

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Agricultural Biomass in MENA

 

Agriculture plays an important role in the economies of most of the countries in the Middle East and North Africa region.  Despite the fact that MENA is the most water-scarce and dry region in the world, many countries in the region, especially those around the Mediterranean Sea, are highly dependent on agriculture.  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.  Large scale irrigation coupled with mechanization has enabled entensive production of high-value cash crops, including fruits, vegetables, cereals, and sugar in the Middle East.

The term ‘crop residues’ covers the whole range of biomass produced as by-products from growing and processing crops. Crop residues encompasses all agricultural wastes such as bagasse, straw, stem, stalk, leaves, husk, shell, peel, pulp, stubble, etc. Wheat and barley are the major staple crops grown in the Middle East region. In addition, significant quantities of rice, maize, lentils, chickpeas, vegetables and fruits are produced throughout the region, mainly in Egypt, Tunisia, Saudi Arabia, Morocco and Jordan. 

Egypt is the one of world's biggest producer of rice and cotton and produced about 5.67 million tons of rice and 635,000 tons of cotton in 2011. Infact, crop residues are considered to be the most important and traditional source of domestic fuel in rural Egypt. The total amount of crop wastes in Egypt is estimated at about 16 million tons of dry matter per year. Cotton residues represent about 9% of the total amount of residues. These are materials comprising mainly cotton stalks, which present a disposal problem. The area of cotton crop cultivation accounts for about 5% of the cultivated area in Egypt.

Agricultural output is central to the Tunisian economy. Major crops are cereals and olive oil, with almost half of all the cultivated land sown with cereals and another third planted. Tunisia is one of the world's biggest producers and exporters of olive oil, and it exports dates and citrus fruits that are grown mostly in the northern parts of the country.

To sum up, 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 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.

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