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. Large scale agricultural irrigation is expanding, enabling intensive production of high value cash and export crops, including fruits, vegetables, cereals, and sugar.
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, Syria, Saudi Arabia and Jordan.
Agricultural Wastes in the Middle East
Large quantities of agricultural wastes are produced annually in the Middle East, and are vastly underutilised. Current farming practice in the Middle East 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, solid fuels or thermochemically processed to produce electricity and domestic heat in rural areas.
Date palm biomass is an excellent resource for charcoal production in Middle East
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. 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.
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.
In Egypt, crop residues are considered to be the most important and traditional source of domestic fuel in rural areas. These crop residues are by-products of common crops such as cotton, wheat, maize and rice. The total amount of residues reaches 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.
A cotton field in Egypt
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.
A wide range of thermal technologies exists to harness the energy stored in biomass. These biomass thermal technologies can be classified according to the principal energy carrier produced in the conversion process. Carriers are in the form of heat, gas, liquid and/or solid products, depending on the extent to which oxygen is admitted to the conversion process (usually as air). The major methods for thermal conversion of biomass are combustion, gasification and pyrolysis.
1. Combustion
Conventional combustion technologies raise steam through the combustion of biomass. This steam may then be expanded through a conventional turbo-alternator to produce electricity. A number of combustion technology variants have been developed. Underfeed stokers are suitable for small scale boilers up to 6 MWth.
Grate type boilers are widely deployed. They have relatively low investment costs, low operating costs and good operation at partial loads. However, they can have higher NOx emissions and decreased efficiencies due to the requirement of excess air, and they have lower efficiencies.
Fluidized bed combustors (FBC), which use a bed of hot inert material such as sand, are a more recent development. Bubbling FBCs are generally used at 10-30 MWth capacity, while Circulating FBCs are more applicable at larger scales. Advantages of FBCs are that they can tolerate a wider range of poor quality fuel, while emitting lower NOx levels.
2. Co-Firing
Co-firing or co-combustion of biomass wastes with coal and other fossil fuels can provide a short-term, low-risk, low-cost option for producing renewable energy while simultaneously reducing the use of fossil fuels. Co-firing involves utilizing existing power generating plants that are fired with fossil fuel (generally coal), and displacing a small proportion of the fossil fuel with renewable biomass fuels.
Co-firing has the major advantage of avoiding the construction of new, dedicated, waste-to-energy power plant. Co-firing may be implemented using different types and percentages of wastes in a range of combustion and gasification technologies. Most forms of biomass wastes are suitable for co-firing. These include dedicated municipal solid wastes, wood waste and agricultural residues such as straw and husk.
3. Gasification
Gasification of biomass takes place in a restricted supply of oxygen and occurs through initial devolatilization of the biomass, combustion of the volatile material and char, and further reduction to produce a fuel gas rich in carbon monoxide and hydrogen. This combustible gas has a lower calorific value than natural gas but can still be used as fuel for boilers, for engines, and potentially for combustion turbines after cleaning the gas stream of tars and particulates.
Layout of a Typical Biomass Gasification Plant
If gasifiers are ‘air blown’, atmospheric nitrogen dilutes the fuel gas to a level of 10-14 percent that of the calorific value of natural gas. Oxygen and steam blown gasifiers produce a gas with a somewhat higher calorific value. Pressurized gasifiers are under development to reduce the physical size of major equipment items.
A variety of gasification reactors have been developed over several decades. These include the smaller scale fixed bed updraft, downdraft and cross flow gasifiers, as well as fluidized bed gasifiers for larger applications. At the small scale, downdraft gasifiers are noted for their relatively low tar production, but are not suitable for fuels with low ash melting point (such as straw). They also require fuel moisture levels to be controlled within narrow levels.
4. Pyrolysis
Pyrolysis is the term given to the thermal degradation of wood in the absence of oxygen. It enables biomass to be converted to a combination of solid char, gas and a liquid bio-oil. Pyrolysis technologies are generally categorized as “fast” or “slow” according to the time taken for processing the feed into pyrolysis products. These products are generated in roughly equal proportions with slow pyrolysis. Using fast pyrolysis, bio-oil yield can be as high as 80 percent of the product on a dry fuel basis.
Bio-oil can act as a liquid fuel or as a feedstock for chemical production. A range of bio-oil production processes are under development, including fluid bed reactors, ablative pyrolysis, entrained flow reactors, rotating cone reactors, and vacuum pyrolysis.
Biomass pellets are a popular type of biomass fuel, generally made from wood wastes, agricultural biomass, commercial grasses and forestry residues. In addition to savings in transportation and storage, pelletization of biomass facilitates easy and cost effective handling. Dense cubes pellets have the flowability characteristics similar to those of cereal grains. The regular geometry and small size of biomass pellets allow automatic feeding with very fine calibration. High density of pellets also permits compact storage and rational transport over long distance. Pellets are extremely dense and can be produced with a low moisture content that allows them to be burned with very high combustion efficiency.
Biomass pelletization is a standard method for the production of high density, solid energy carriers from biomass. Pellets are manufactured in several types and grades as fuels for electric power plants, homes, and other applications. Pellet-making equipment is available at a variety of sizes and scales, which allows manufacture at domestic as well industrial-scale production. Pellets have a cylindrical shape and are about 6-25 mm in diameter and 3-50 mm in length. There are European standards for biomass pellets and raw material classification (EN 14961-1, EN 14961-2 and EN 14961-6) and international ISO standards under development (ISO/DIS 17225-1, ISO/DIS 17225-2 and ISO/DIS 17225-6).
Process Description
The biomass pelletization process consists of multiple steps including raw material pre-treatment, pelletization and post-treatment. The first step in the pelletization process is the preparation of feedstock which includes selecting a feedstock suitable for this process, its filtration, storage and protection. Raw materials used are sawdust, wood shavings, wood wastes, agricultural residues like straw, switchgrass etc. Filtration is done to remove unwanted materials like stone, metal, etc. The feedstock should be stored in such a manner that it is away from impurities and moisture. In cases where there are different types of feedstock, a blending process is used to achieve consistency.
The moisture content in biomass can be considerably high and are usually up to 50% – 60% which should be reduced to 10 to 15%. Rotary drum dryer is the most common equipment used for this purpose. Superheated steam dryers, flash dryers, spouted bed dryers and belt dryers can also be used. Drying increases the efficiency of biomass and it produces almost no smoke on combustion. It should be noted that the feedstock should not be over dried, as a small amount of moisture helps in binding the biomass particles. The drying process is the most energy intensive process and accounts for about 70% of the total energy used in the pelletization process.
Schematic of Pelletization of Woody Biomass
Beforefeeding biomass to pellet mills, the biomass should be reduced to small particles of the order of not more than 3mm. If the pellet size is too large or too small, it affects the quality of pellet and in turn increases the energy consumption. Therefore the particles should have proper size and should be consistent. Size reduction is done by grinding using a hammer mill equipped with a screen of size 3.2 to 6.4 mm. If the feedstock is quite large, it goes through a chipper before grinding.
The next and the most important step is pelletization where biomass is compressed against a heated metal plate (known as die) using a roller. The die consists of holes of fixed diameter through which the biomass passes under high pressure. Due to the high pressure, frictional forces increase, leading to a considerable rise in temperature. High temperature causes the lignin and resins present in biomass to soften which acts as a binding agent between the biomass fibers. This way the biomass particles fuse to form pellets.
The rate of production and electrical energy used in the pelletization of biomass are strongly correlated to the raw material type and processing conditions such as moisture content and feed size. The The average energy required to pelletize biomass is roughly between 16 kWh/t and 49kWh/t. During pelletization, a large fraction of the process energy is used to make the biomass flow into the inlets of the press channels.
Binders or lubricants may be added in some cases to produce higher quality pellets. Binders increase the pellet density and durability. Wood contains natural resins which act as a binder. Similarly, sawdust contains lignin which holds the pellet together. However, agricultural residues do not contain much resins or lignin, and so a stabilizing agent needs to be added in this case. Distillers dry grains or potato starch is some commonly used binders. The use of natural additives depends on biomass composition and the mass proportion between cellulose, hemicelluloses, lignin and inorganics.
Due to the friction generated in the die, excess heat is developed. Thus, the pellets are very soft and hot (about 70 to 90oC). It needs to be cooled and dried before its storage or packaging. The pellets may then be passed through a vibrating screen to remove fine materials. This ensures that the fuel source is clean and dust free.
The pellets are packed into bags using an overhead hopper and a conveyor belt. Pellets are stored in elevated storage bins or ground level silos. The packaging should be such that the pellets are protected from moisture and pollutants. Commercial pellet mills and other pelletizing equipment are widely available across the globe.
Biomass logistics involves all the unit operations necessary to move biomass wastes from the land to the biomass energy plant. The biomass can be transported directly from farm or from stacks next to the farm to the processing plant. Biomass may be minimally processed before being shipped to the plant, as in case of biomass supply from the stacks. Generally the biomass is trucked directly from farm to the biomass processing facility if no processing is involved.
Another option is to transfer the biomass to a central location where the material is accumulated and subsequently dispatched to the energy conversion facility. While in depot, the biomass could be pre-processed minimally (ground) or extensively (pelletized). The depot also provides an opportunity to interface with rail transport if that is an available option. The choice of any of the options depends on the economics and cultural practices. For example in irrigated areas, there is always space on the farm (corner of the land) where quantities of biomass can be stacked.
The key components to reduce costs in harvesting, collecting and transportation of biomass can be summarized as:
Reduce the number of passes through the field by amalgamating collection operations.
Increase the bulk density of biomass
Work with minimal moisture content.
Granulation/pelletization is the best option, though the existing technology is expensive.
Trucking seems to be the most common mode of biomass transportation option but rail and pipeline may become attractive once the capital costs for these transport modes are reduced.
The logistics of transporting, handling and storing the bulky and variable biomass material for delivery to the biopower plant is a key part of the biomass supply chain that is often overlooked by project developers. Whether the biomass comes from forest residues on hill country, straw residues from cereal crops grown on arable land, or the non-edible components of small scale, subsistence farming systems, the relative cost of collection will be considerable.
Careful development of a system to minimize machinery use, human effort and energy inputs can have a considerable impact on the cost of the biomass as delivered to the biomass processing plant gate.
The logistics of supplying a biomass power plant with consistent and regular volumes of biomass are complex.
Most of the agricultural biomass resources tend to have a relatively low energy density compared with fossil fuels. This often makes handling, storage and transportation more costly per unit of energy carried. Some crop residues are often not competitive because the biomass resource is dispersed over large areas leading to high collection and transport costs.
The costs for long distance haulage of bulky biomass will be minimized if the biomass can be sourced from a location where it is already concentrated, such as sugar mill. It can then be converted in the nearby biomass energy plant to more transportable forms of energy carrier if not to be utilized on-site.
The logistics of supplying a biopower plant with sufficient volumes of biomass from a number of sources at suitable quality specifications and possibly all year round, are complex. Agricultural residues can be stored on the farm until needed. Then they can be collected and delivered directly to the conversion plant on demand. At times this requires considerable logistics to ensure only a few days of supply are available on-site but that the risk of non-supply at any time is low.
Losses of dry matter, and hence of energy content, commonly occur during the harvest transport and storage process. This can either be from physical losses of the biomass material in the field during the harvest operation or dropping off a truck, or by the reduction of dry matter of biomass material which occurs in storage over time as a result of respiration processes and as the product deteriorates. Dry matter loss is normally reduced over time if the moisture content of the biomass can be lowered or oxygen can be excluded in order to constrain pathological action.
To ensure sufficient and consistent biomass supplies, all agents involved with the production, collection, storage, and transportation of biomass require compensation for their share of costs incurred. In addition, a viable biomass production and distribution system must include producer incentives, encouraging them to sell their post-harvest plant residue.
China has recently emerged as one of the economic powerhouses of the world. Not only does this status continue to redefine what was considered to represent a somewhat “backwards” society, but plenty of employment opportunities await. This has also given rise to several interesting trends. From the growing number of Chinese classes online which cater to foreign migrants to increased international investment, the future does indeed look bright.
It is also important to mention how China has begun to capitalise upon innovative solutions in the hopes of reducing the impacts of climate change. One interesting example can be seen in the use of bioenergy as a viable substitute for traditional fossil fuels. What are some current trends to note and are there any challenges that will need to be addressed in the coming years?
Promising Statistics
Many readers will be surprised to learn that up to 80 per cent of raw biomass materials are now being used to generate power throughout China. Considering the population of this nation, it only stands to reason that such sources of energy abound. Furthermore, the implementation of biomass will help to reduce China’s reliance upon outside nations. This provides a much-needed economic boost and promises an impressive long-term return on investment (ROI).
Such a pronounced trend is at least partially due to a younger Chinese generation that has now become well aware of their role in stemming the effects of climate change. Another undeniable benefit is the simple fact that bioenergy now represents a niche employment sector; providing plenty of opportunities for those with the appropriate skill sets.
What Challenges Await?
While all of the observations outlined above are rather promising, we also need to remember that there are some downsides attributed to biomass in relation to energy production. One potential issue involves industry competition as well as to decide how the resources themselves should be allocated. Wealth distribution could also come into play considering the role that corruption may play in terms of profit margins.
As this summary highlights, another possible sticking point could instead involve operational challenges including:
Other problems such as retooling existing factories in order to support biomass energy production can be rather complicated and expensive.
So, what might the future of bioenergy in China have in store? Most experts agree that relying upon fossil fuels alone as a source of electricity is no longer a viable option. So, it stands to reason that the Chinese government is looking carefully at how biomass can be used as an alternative. Officials also appreciate that many other nations have already curtailed their use of fuels such as coal and natural gas.
The main takeaway point here is that much like any other emerging industry, bioenergy is associated with undeniable advantages as well as some logistical challenges. Still, China should be able to rise to the occasion with planning and foresight.
Transporting biomass fuel to a power plant is an important aspect of any biomass energy project. Because a number of low moisture fuels can be readily collected and transported to a centralized biomass plant location or aggregated to enhance project size, this opportunity should be evaluated on a case-by-case basis.
It will be a good proposition to develop biomass energy plants at the location where the bulk of the agricultural waste stream is generated, without bearing the additional cost of transporting waste streams. Effective capture and use of thermal energy at the site for hot water, steam, and even chilled water requirements raises the energy efficiency of the project, thereby improving the value of the waste-to-energy project.
Important Factors
The maximum rate of biomass supply to the conversion facility.
The form and bulk density of biomass.
The hauling distance for biomass transportation to the processing plant.
Transportation infrastructure available between the points of biomass dispatch and processing plant
Transportation is primarily concerned with loading and unloading operation and transferring biomass from pre-processing sites to the main processing plant or biorefinery. Truck transport and for a few cases train transport may be the only modes of transport. Barge and pipeline transport and often train transport involve truck transport. Trucks interface with trains at loading and unloading facilities of a depot or processing facility. Barge and pipeline require interfacing with train and/or truck transport at major facilities either on land or at the shores.
Physical form and quality of biomass has the greatest influence on the selection of handling equipment for the lowest delivered cost possible. A higher bulk density will allow more mass of material to be transported per unit distance. Truck transport is generally well developed, is usually cheapest mode of transport but it becomes expensive as travel distance increases. Pipeline biomass transport is the least known technology and may prove to be the cheapest and safest mode of transport in the near future.
Transportation costs of low-density and high-moisture agricultural residues are a major constraint to their use as an energy source. As a rule of thumb, transportation distances beyond a 25–50- km radius (depending on local infrastructure) are uneconomical. For long distances, agricultural residues could be compressed as bales or briquettes in the field, rendering transport to the site of use a viable option.
Greater use of biomass and larger scale conversion systems demand larger scale feedstock handling and delivery infrastructure. To accommodate expansion in feedstock collection and transportation, production centres can be established where smaller quantities of biomass are consolidated, stored, and transferred to long-distance transportation systems, in much the same way that transfer stations are used in municipal waste handling. Preprocessing equipment may be used to densify biomass, increasing truck payloads and reducing transportation costs over longer haul distances.
The term agricultural residue is used to describe all the organic materials which are produced as by-products from harvesting and processing of agricultural crops. These residues can be further categorized into primary residues and secondary residues.
Agricultural residues, which are generated in the field at the time of harvest, are defined as primary or field based residues whereas those co-produced during processing are called secondary or processing based residues.
Primary agricultural residues – paddy straw, sugarcane top, maize stalks, coconut empty bunches and frond, palm oil frond and bunches;
Agricultural residues are highly important sources of biomass fuels for both the domestic and industrial sectors. Availability of primary residues for energy application is usually low since collection is difficult and they have other uses as fertilizer, animal feed etc.
However secondary residues are usually available in relatively large quantities at the processing site and may be used as captive energy source for the same processing plant involving minimal transportation and handling cost.
Crop residues encompasses all agricultural wastes such as straw, stem, stalk, leaves, husk, shell, peel, pulp, stubble, etc. which come from cereals (rice, wheat, maize or corn, sorghum, barley, millet), cotton, groundnut, jute, legumes (tomato, bean, soy) coffee, cacao, tea, fruits (banana, mango, coco, cashew) and palm oil.
Rice produces both straw and rice husks at the processing plant which can be conveniently and easily converted into energy. Significant quantities of biomass remain in the fields in the form of cob when maize is harvested which can be converted into energy.
Storage of biomass fuels is expensive and increases with capacity.
Sugarcane harvesting leads to harvest residues in the fields while processing produces fibrous bagasse, both of which are good sources of energy. Harvesting and processing of coconuts produces quantities of shell and fibre that can be utilised while peanuts leave shells. All these materials can be converted into useful energy by a wide range of biomass conversion technologies.
The steel manufacturing industry is one of the highest carbon emission sources globally, leading to the highest CO2 emissions into the atmosphere. The process from converting iron ore to graded steel includes a blast furnace, followed by a basic oxygen furnace and an electric arc furnace. The highest emissions are generated during coke production, blast furnace, i.e., Energy demand and GHG emissions in the Iron and Steel sector principally result from the large consumption of coal/coke used in conjunction with the blast furnace.
What is Green Steel
Green steel refers to the process of steel manufacturing with reduced GHG emissions into the atmosphere as well as potentially reducing cost and improving steel quality, as compared to conventional steel production. A study indicates that steel demand will keep on rising until the end of the 21st century, so there is a huge motivation to look for an alternative method of steel production that emits low greenhouse gas (GHG) emissions into the atmosphere.
Scrap steel recycling is a positive step toward alleviating emissions. However, based on the available scrap, this route can contribute 44% of the total steel production by the end of 2050, which is not sufficient to meet the growing demands.
Also, the issue with recycled steel is that they are contaminated with copper and tin, which causes surface cracking during the hot rolling process. An integrated steel recycling process with innovative routes can bring down the global warming to a manageable threat.
Blast furnace (BF) and basic oxygen furnace (BOF) contribute to 70% of total GHG emissions into the environment. The process reduces iron into ores, sinter and pellets using carbon-based lowering agents. Fluxes (or steel scrap) are added to the blast furnace to maintain the slag temperature and separate the impurities. The hot metal produced contains sulphur, phosphorous, manganese and silicon. The impurities are heated/reduced in BOF to produce high-quality steel with carbon below 2%. High Calcium and dolomite lime are utilized in multiple stages of this procedure and result in various improvements and advantages.
According to research, hydrogen-based and electricity-based steel production have minimal emissions into the atmosphere. However, this technology is still under investigation, some small-scale development has been done in the past, but large scale development is still under development phase.
Pathways for Green Steel Production – Opportunities and Challenges
Various alternative ways exist to produce low-grade carbon products such as carbon capture and storage (CCS), renewable hydrogen and high utilisation of biomass resources. The use of artificial iron units (AIUs) in iron steel production can reduce significant carbon emissions and high-grade steel production.
To minimize emissions, scrap use must be incorporated into the manufacturing process. The use of bioenergy resources in steel production can be a good option, but that goes through a long list of concerns, such as biomass availability, the capital cost of replacement of existing technology.
An Integrated Iron and Steel Mill (ISM) consists of many complex series of interconnected plants, where emissions come out from many sources (10 or more). Huge amount of CO2 is produced by the reduction reaction reactions occurring in the blast furnace and the combustion reaction in sintering, blast furnace and basic oxygen furnace.
Biomass can be used for steel production in place of coal, but this is discouraged by most industries, mainly because of huge biomass requirement, transportation, and storage requirement. Another alternative is the use of natural gas, which at present accounts for 20% of overall steel production in the world. Natural gas produces GHG emissions, which is feasible for small scale goals. If the end target is to achieve significant scale goals, then natural gas use integrated with carbon capture technology is beneficial.
The absorption process is another method used to separate CO2 from gas streams using chemical solvents. However, this process is very expensive because of the high thermal energy required to break the strong bond between solvents and CO2.
Adsorption is also a process to reduce CO2 where a gas stream is passed through the solid adsorbent (such as zeolites, activated carbon). The bed loaded with reduced pressure, increased temperature, and low voltage electric current is challenging to maintain to also expensive.
Gas separation is also a method to reduce GHG emissions, which works on the development of gas separation membranes (polymers, ceramics, zeolites and metals), depending on the difference in physical and chemical interactions. The reducing efficiency reaches up to 80% CO2 separation. In 2007, a simulation study revealed 97% of CO2 recovery from blast furnace gas. Ongoing research in Australia where researchers are developing new technology for gas separation membrane. The research aims to test a number of separation strategies, investigate the influence of syngas and minor gas components.
Hydrogen-based steel making route is another positive step toward green steel. Two different routes exist, direct hydrogen reduction and hydrogen plasma reduction. Small scale utilisation of hydrogen with up to 70% volume reduction was achieved, but the large-scale application is still under development.
The challenge lies mostly with the hydrogen-based DRI process, it produces 0% carbon which does not fulfil the carbon demand of the downstream process. The second issue is the supply of sufficient hydrogen. According to the study, the electricity cost for hydrogen production, considering the electrolysis to produce the hydrogen, should be less than 0.02 USD/kWh to make the process economically feasible. However, hydrogen storage supply and transportation costs are other scopes that still need to be explored.
Closing Comments
As on closing comments, steel production is one of the highest GHG emitting sources globally. If not controlled, the commitment at Paris Climate Summit 2015 to hold global temperature below 2℃ seems lost way before the set target date of 2050.
Promoting green steel production can be majorly significant with the targets. Technologies exist that can reduce GHG emissions, and some of them are under commission at a small scale; however, large scale implementation is yet to get approval from research integrity.
Existing technologies are very expensive, or they do have technical challenges which are economically costly to manage. Hydrogen-based steel production is a technology that looks very promising. Researchers are working on the project to analyse the economic and technical feasibility at a large scale.
Considering the fact that Pakistan is among the world’s top-10 sugarcane producers, the potential of generating electricity from bagasse is huge. Almost all the sugar mills in Pakistan have in-house plants for cogeneration but they are inefficient in the consumption of bagasse. If instead, high pressure boilers are installed then the production capacity can be significantly improved with more efficient utilization of bagasse.
However, due to several reasons; mostly due to financing issues, the sugar mill owners were not able to set up these plants. Only recently, after financial incentives have been offered and a tariff rate agreed upon between the government and mill owners, are these projects moving ahead.
The sugar mill owners are more than willing to supply excess electricity generated form the in-house power plants to the national grid but were not able to before, because they couldn’t reach an agreement with the government over tariff. The demand for higher tariff was justified because of large investments in setting up new boilers. It would also have saved precious foreign exchange which is spent on imported oil.
By estimating the CDM potential of cogeneration (or CHP) projects based on biofuels, getting financing for these projects would be easier. Renewable energy projects can be developed through Carbon Development Mechanism or any other carbon credit scheme for additional revenue.
Since bagasse is a clean fuel which emits very little carbon emissions it can be financed through Carbon Development Mechanism. One of the reasons high cogeneration power plants are difficult to implement is because of the high amount of costs associated. The payback period for the power plants is unknown which makes the investors reluctant to invest in the high cogeneration project. CDM financing can help improve the rate of return of the project.
Bagasse power plants generate Carbon Emission Reductions in 2 ways; one by replacing electricity produced from fossil fuels. Secondly if not used as a fuel, it would be otherwise disposed off in an unsafe manner and the methane emissions present in biomass would pollute the environment far more than CO2 does.
Currently there are around 83 sugar mills in Pakistan producing about 3.5 million metric tons of sugar per annum with total crushing capacity 597900 TCD, which can produce approximately 3000 MW during crop season Although it may seem far-fetched at the moment, if the government starts to give more attention to sugar industry biomass rather than coal, Pakistan can fulfill its energy needs without negative repercussions or damage to the environment.
However some sugar mills are opting to use coal as a secondary fuel since the crushing period of sugarcane lasts only 4 months in Pakistan. The plants would be using coal as the main fuel during the non-crushing season. The CDM effect is reduced with the use of coal. If a high cogeneration plant is using even 80% bagasse and 20% of coal then the CERs are almost nullified. If more than 20% coal is used then the CDM potential is completely lost because the emissions are increased. However some sugar mills are not moving ahead with coal as a secondary fuel because separate tariff rates have to be obtained for electricity generation if coal is being used in the mix which is not easily obtained.
Pakistan has huge untapped potential for bagasse-based power generation
One of the incentives being offered by the State Bank of Pakistan is thatif a project qualifies as a renewable project it is eligible to get loan at 6% instead of 12%. However ones drawback is that, in order to qualify as a renewable project, CDM registration of a project is not taken into account.
Although Pakistan is on the right track by setting up high cogeneration power plants, the use of coal as a secondary fuel remains debatable. The issue that remains to be addressed is that with such huge amounts of investment on these plants, how to use these plants efficiently during non-crushing period when bagasse is not available. It seems almost counter-productive to use coal on plants which are supposed to be based on biofuels.
Conclusion
With the demand for energy in Pakistan growing, the country is finally exploring alternatives to expand its power production. Pakistan has to rely largely on fossils for their energy needs since electricity generation from biomass energy sources is considered to be an expensive option despite abundance of natural resources. However by focusing on growing its alternate energy options such as bagasse-based cogeneration, the country will not only mitigate climate change but also tap the unharnessed energy potential of sugar industry biomass.
Biomass is material originating from plant and animal matter. Biomass energy uses biomass to create energy by burning organic materials. The heat energy released through burning these materials can heat homes or water. Heated water produces steam, which in turn can generate electricity. Using organic materials to create heat and power is an eco-friendlier alternative compared to using fossil fuels. Here’s more about the benefits of biomass energy
1. Indefinitely Renewable
The majority of the world’s energy comes from burning fossil fuels. Fossil fuels are a finite resource. Once fossil fuel resources run out, new fuel sources will be needed to meet global energy demands. Biomass offers a solution to meet this need.
Organic waste material from agriculture and logging operations, animal manure, and sludge from wastewater treatment are all viable fuels for generating biomass energy. As long as the earth is inhabited, these materials will be readily available.
2. Reduce, Reuse, Recycle
Organic waste that would typically be disposed of in landfills could be redirected for biomass energy use. This reduces the amount of material in landfills and slows the rate at which landfills are filled. Some of the most common waste products used for biomass energy are wood chips and agricultural waste products. Wood materials can easily be converted from already existing wood structures that will be destroyed, such as wooden furniture and log cabins, preferably both would also come from responsible logging and practices as well.
As more organic waste is diverted from landfills, the number of new landfills needed would be reduced. Older landfills are at risk for leaking leachate. Leachate contains many environmental pollutants that can contaminate groundwater sources.
Burning fossil fuel releases carbon into the atmosphere which was previously trapped below ground. Trapped carbon isn’t at risk for contributing to global climate change since it can’t interact with air. Each time fossil fuels are burned, they allow previously trapped carbon to enter the atmosphere and contribute to global climate change. In comparison, biofuel is carbon-neutral.
The materials used to create biomass energy naturally release carbon into the environment as they decompose. Living plants and trees use carbon dioxide to grow and release oxygen into the atmosphere. Carbon dioxide released by burning organic material will be absorbed by existing plants and trees. The biomass cycle is carbon-neutral as no new carbon is introduced to the system.
3. Smaller Carbon Footprint
The amount of unused farmland is increasing as agriculture becomes more efficient. Maintaining open land is expensive. As a result, farmers are selling off their property for new developments. Unused open agricultural land could be used to grow organic material for biofuels.
Converting open tracts of land to developed areas increases the amount of storm-water runoff. Storm-water runoff from developed areas contains more pollutants than storm-water runoff from undeveloped areas. Using open areas to grow biomass sources instead of creating new developments would reduce water pollution.
A quick glance at popular biomass resources
Forested areas also provide sources of biofuel material. Open land converted to sustainable forestry would create new animal habitats and offset carbon emissions from existing fossil fuel sources as more plants and trees would be available to absorb carbon dioxide.
4. Social Benefits of Biomass Energy
Burning fossil fuels releases sulfur dioxide, mercury and particulate matter into the atmosphere which can cause asthma, cancer and respiratory problems. Biomass energy emits less harmful byproducts compared to fossil fuels, which means cleaner air and healthier people.
Biofuel can improve rural economies by providing more people with unused land the opportunity to grown biomass material for energy use. Workers would be needed to harvest and process the materials needed to generate biofuel.
Since biomass is a renewable energy source, energy providers can receive tax credits and incentives. Countries with land resources will be less reliant on foreign fossil fuel providers and can improve their local economies.
Increasing biomass energy usage can reduce forest fires. Selectively reducing brush can still reduce the risk of wildfires spreading. Exposing underbrush and groundcover to rainfall decreases the change of it drying out and creating optimal, fire spreading conditions.
Woody biomass creates an increasing percentage of heating from combined heat and power (CHP) plants with a goal to for 100 percent of hearing to be derived from woody biomass by 2035. Another form of biomass is agricultural biomass. This form utilizes materials such as straw and corn to create end-products like electricity, heating and biofuels.
The Danish Energy Agency has developed a plan including four scenarios that will help Denmark become fossil fuel free by 2050. The biomass scenario involves CHP for electricity and district heating, indicating that biomass energy is important in Denmark’s energy sector today and will play an increasingly important role in the future.
Biomass offers an eco-friendly and renewable method of reducing pollution and the effects of global climate change. And, like other forms of renewable energy, the products needed to develop biomass energy are readily available.
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