About Salman Zafar

Salman Zafar is the CEO of BioEnergy Consult, and an international consultant, advisor and trainer with expertise in waste management, biomass energy, waste-to-energy, environment protection and resource conservation. His geographical areas of focus include Asia, Africa and the Middle East. Salman has successfully accomplished a wide range of projects in the areas of biogas technology, biomass energy, waste-to-energy, recycling and waste management. Salman has participated in numerous national and international conferences all over the world. He is a prolific environmental journalist, and has authored more than 300 articles in reputed journals, magazines and websites. In addition, he is proactively engaged in creating mass awareness on renewable energy, waste management and environmental sustainability through his blogs and portals. Salman can be reached at salman@bioenergyconsult.com or salman@cleantechloops.com.

Solid Waste Management in Kuwait

Kuwait, being one of the richest countries, is among the highest per capita waste generators in the world. Each year more than 2 million tons of solid waste is generated in the tiny Arab nation. High standards of living and rapid economic growth has been a major factor behind very high per capita waste generation of 1.4 to 1.5 kg per day.

The prevalent solid waste disposal method in Kuwait is landfill burial. Despite being a small country, Kuwait has astonishingly high number of landfills. There are 18 landfills, of which 14 sites are closed and 4 sites are still in operation. These landfills act as dumpsites, rather than engineered landfills.

Infact, landfill sites in Kuwait are notorious for causing severe public health and environmental issues. Besides piling up huge amounts of garbage, landfill sites generate huge amount of toxic gases (methane, carbon dioxide etc) and plagued by spontaneous fires. Due to fast paced urban development, residential areas have expanded to the edges of landfill sites thus causing grave danger to public health.

The total land area of Kuwait is around 17,820 sq. km, out of which more than 18 sq. km is occupied by landfills. Area of the landfill sites ranges from tens to hundreds of hectares with waste deposition depth varying from 3 to 30 meters. All kind of wastes, including municipal wastes, food wastes, industrial wastes, construction and demolition debris etc are dumped at these sites. Infact, about 90 percent of the domestic waste is sent to landfills which imply that more landfills will be required to tackle rapidly increasing volumes of solid wastes.

Most of the landfill sites have been closed for more than 20 years due to operational problems and proximity to new residential, commercial and industrial areas. These sites include Sulaibiyah, Kabed, Al?Qurain, Shuaiba, Jleeb AI Shuyoukh, West Yarmouk, AI Wafra among others. Migration of leachate beyond landfill site boundaries is a frequent problem noticed across Kuwait. Groundwater contamination has emerged as a serious problem because groundwater occurs at shallow depths throughout the country.

The major landfill sites operated by municipality for solid waste disposal are Jleeb AI Shuyoukh, Sulaibiyah and Al-Qurain. The Qurain landfill, with area of 1 sq. km, was used for dumping of municipal solid waste and construction materials from 1975 until 1985 with total volume of dumped waste being 5 million m3. The Sulaibiyah landfill site received more than 500 tons of waste per day from 1980 to 2000 with area spanning 3 sq. km. Jleeb AI Shuyoukh, largest landfill site in Kuwait with area exceeding 6 sq. km, received 2500 tons per day of household and industrial waste between 1970 and 1993. Around 20 million m3 of wastes was dumped in this facility during its operational period.

Over the years, most of the dumpsites in Kuwait have been surrounded by residential and commercial areas due to urban development over the years. Uncontrolled dumpsites were managed by poorly-trained staff resulting in transformation of dumpsites in breeding grounds for pathogens, toxic gases and spontaneous fires.

Most of the landfill sites have been forced to close, much before achieving their capacities, because of improper disposal methods and concerns related to public health and environment. Due to fast-paced industrial development and urban expansion, some of the landfills are located on the edges of residential, as is the case of Jleeb Al-Shuyoukh and Al-Qurain sites, endangering the lives of hundreds of thousands of people.

Biomass Gasfication Power Systems

Biomass power systems using biomass gasification has followed two divergent pathways, which are a function of the scale of operations. At sizes much less than 1MW, the preferred technology combination today is a moving bed gasifier and ICE combination, while at scales much larger than 10 MW, the combination is of a fluidized bed gasifier and a gas turbine. Larger scale units than 25 MW would justify the use of a combined cycle, as is the practice with natural gas fired gas turbine stations. In the future it is anticipated that extremely efficient gasification based power systems would be based on a combined cycle that incorporates a fuel cell, gas turbine and possibly a Rankine bottoming cycle.

Integrated Gasification Combined Cycle

The most attractive means of utilising a biomass gasifier for power generation is to integrate the gasification process into a gas turbine combined cycle power plant. This will normally require a gasifier capable of producing a gas with heat content close to 19 MJ/Nm3. A close integration of the two parts of the plant can lead to significant efficiency gains.

The gas from the gasifier must first be cleaned to remove impurities such as alkali metals that might damage the gas turbine. The clean gas is fed into the combustor of the gas turbine where it is burned, generating a flow of hot gas which drives the turbine, generating electricity. Hot exhaust gases from the turbine are then utilised to generate steam in a heat recovery steam generator. The steam drives a steam turbine, producing more power. Low grade waste heat from the steam generator exhaust can be used within the plant, to dry the biomass fuel before it is fed into the gasifier or to preheat the fuel before entry into the gasifier reactor vessel.

The gas-fired combined cycle power plant has become one of the most popular configurations for power generation in regions of the world where natural gas is available. The integration of a combined cycle power plant with a coal gasifier is now considered a potentially attractive means of burning coal cleanly in the future.

Biomass Fuel Cell Power Plant

Another potential use for the combustible gas from a biomass gasification plant is as fuel for a fuel cell power plant. Modern high temperature fuel cells are capable of operating with hydrogen, methane and carbon monoxide. Thus product gas from a biomass gasifier could become a suitable fuel. As with the integrated biomass gasification combined cycle plant, a fuel cell plant would offer high efficiency. A future high temperature fuel cell burning biomass might be able to achieve greater than 50% efficiency.

Composting with Worms

Vermicomposting is a type of composting in which certain species of earthworms are used to enhance the process of organic waste conversion and produce a better end-product. It is a mesophilic process utilizing microorganisms and earthworms. Earthworms feeds the organic waste materials and passes it through their digestive system and gives out in a granular form (cocoons) which is known as vermicompost. Simply speaking, vermicompost is earthworm excrement, called castings, which can improve biological, chemical, and physical properties of the soil. The chemical secretions in the earthworm’s digestive tract help break down soil and organic matter, so the castings contain more nutrients that are immediately available to plants.

Production of Vermicompost

A wide range of agricultural residues, such as straw, husk, leaves, stalks, weeds etc can be converted into vermicompost. Other potential feedstock for vermicompost production are livestock wastes, poultry litter, dairy wastes, food processing wastes, organic fraction of MSW, bagasse, digestate from biogas plants etc. Earthworms consume organic wastes and reduce the volume by 40–60 percent. Each earthworm weighs about 0.5 to 0.6 gram, eats waste equivalent to its body weight and produces cast equivalent to about 50 percent of the waste it consumes in a day. The moisture content of castings ranges between 32 and 66 percent and the pH is around 7. The level of nutrients in compost depends upon the source of the raw material and the species of earthworm.

There are nearly 3600 types of earthworms which are divided into burrowing and non-burrowing types. Red earthworm species, like Eisenia foetida, and are most efficient in compost making. The non-burrowing earthworms eat 10 percent soil and 90 percent organic waste materials; these convert the organic waste into vermicompost faster than the burrowing earthworms. They can tolerate temperatures ranging from 0 to 40°C but the regeneration capacity is more at 25 to 30°C and 40–45 percent moisture level in the pile. The burrowing types of earthworms come onto the soil surface only at night. These make holes in the soil up to a depth of 3.5 m and produce 5.6 kg casts by ingesting 90 percent soil and 10 percent organic waste.

The types of vermicomposting depend upon the amount of producton and composting structures. Small-scale vermicomposting is done to meet personal requirements and farmers/gardeners can harvest 5-10 tons of vermicompost annually. On the other hand, large-scale vermicomposting is done at commercial scale by recycling large quantities of organic waste in modern facilities with the production of more than hundreds of tons annually.

Benefits of Vermicompost

The worm castings contain higher percentage of both macro and micronutrients than the garden compost. Apart from other nutrients, a fine worm cast is rich in NPK which are in readily available form and are released within a month of application. Vermicompost enhances plant growth, suppresses disease in plants, increases porosity and microbial activity in soil, and improves water retention and aeration. Vermicompost also benefits the environment by reducing the need for chemical fertilizers and decreasing the amount of waste going to landfills. Vermicompost production is trending up worldwide and it is finding increasing use especially in Western countries, Asia-Pacific and Southeast Asia.

A relatively new product from vermicomposting is vermicompost tea which is a liquid produced by extracting organic matter, microorganisms, and nutrients from vermicompost. Unlike vermicompost and compost, this tea may be applied directly to plant foliage, reportedly to enhance disease suppression. Vermicompost tea also may be applied to the soil as a supplement between compost applications to increase biological activity.

Vermicompost may be sold in bulk or bagged with a variety of compost and soil blends. Markets include home improvement centers, nurseries, landscape contractors, greenhouses, garden supply stores, grocery chains, flower shops, discount houses, and the general public.

33 Foot Whale Dies From Eating Rubbish

garbage-oceanThis is a true and very sad rubbish clearance story. While this particular incident is certainly a case of “a picture is worth a thousand words” (or more!), we hope that our words give ammunition to those who are working toward positive change to keep our waste removal out of our oceans.

A Gruesome Ghastly Sight

Usually, the sight of a majestic sperm whale is such a magical moment, most people try to freeze frame the image in their mind. In fact, many people stop breathing momentarily they are so excited to see such a magnificent creature! However, this was not the reaction people had on February 27 when a thirty-three foot, totally emaciated, sperm whale washed up dead on Cabo de Palos Beach in southwestern Spain. It was not at all a wondrous sight… it was a gruesome ghastly sight… one of those images that people would prefer to block from their mind but can’t no matter how hard they try!

The sight of this gigantic creature, lying there dead, the life sucked out of it from eating our rubbish clearance, is heartbreaking to everyone who has viewed the scene either in person or via picture. It sent shock waves across the environmental community. Many shared images of the ghostly dead sperm whale on social media. All who saw it seemed utterly horrified, many vowing to do something about it. The mantra seemed to be “Shame on us for allowing this to happen!”

The deceased sperm whale, a juvenile male, weighed in at 6.5 metric tonnes (14,330 pounds, 5900 kilograms). While this may seem massive to a human weighting a mere 175 pounds, it is about seven times less than what male sperm whales usually weigh. He weighed so much less than a juvenile male sperm whale is supposed to weigh, the idiomatic expression, “he was skin and bones,” would not even begin to cover his physical state. It was quite obvious from the pictures that he literally starved to death.

Cause of such a grueling death

Experts at the El Valle Wildlife Recovery Centre  determined that his stomach and intestines were filled with twenty-nine kilograms (sixty-four pounds) of garbage! These included discarded cans, netting, ropes, and plastic bags. With all this rubbish clearance compacting his digestive system, he could not digest real food and he starved to death. In addition, he had a severe stomach infection, most likely because one of the rubbish clearance items he swallowed ripped a tear in his stomach lining.

The pain and torture this young sperm whale must have endured before he finally died and washed ashore to shame humanity must have been extensive. How unjust it is to this creature to not only die but actually die in a way that was very likely slow and tremendously painful.

What do we as humans owe his species for the sin of his death? Should his death be the impetus to do more to rid our oceans of rubbish removal? Should we plaster this image of this whales lifeless emaciated body on anti-litter posters even though it makes us feel awkward and ashamed to see it?

Sperm Whale – A Magnificent Creature

Sperm whales have been forever immortalized in the great novel, Moby Dick, so they will live for eternity on in the human psyche even if they go extinct. However, unlike the dinosaurs that roamed our planet before our time, and went extinct long before we made our great migration out of Africa into the fertile crescent, sperm whales have shared our planet for all of human history.

Many members of our species have come eye to eye with this beast and we must answer for our crimes of littering that has been proven to be the direct cause of this whales death, and in fact, threatens his entire species.

The International Union for Conservation of Nature (IUCN) classifies the conservation status of sperm whales as “vulnerable” which is only one small step away from becoming endangered — and some experts actually argue that sperm whales are already endangered. While it is impossible to do an accurate census of sperm whales, scientists estimate there about 200,000 of these whales left. Keep in mind, there used to be many millions of them in our oceans but they were a favorite of whaling expeditions who hunted them for their valuable blubber, meat, and even their bones.

Sperm whales are now protected under international law so most countries no longer hunt them. However, the Japanese still have a taste for sperm whale and several are harvested for supposed “scientific research” every year. The whale meat from these scientific specimens does get sold in Japanese markets. However, even given this loophole in the law that protects sperm whales, the direct human harvesting of sperm whales pales in comparison to how threatening our rubbish clearance is to the endurance of this species.

Time for Introspection

The sperm whale that washed up dead on Cabo de Palos Beach is only one of many who have died due to eating rubbish clearance. Plastic bags are the biggest culprit but all rubbish in our oceans poses a dire threat to sperm whales and other marine mammals. What we do about our rubbish clearance problem over the next few decades will likely determine the fate of this entire species and many other marine mammals.

The stomach and intestines of sperm whale was filled with 29 kg of garbage

It is important to note how intelligent sperm whales are though to be. Sperm whales have the biggest brains in the animal kingdom, weighing in at five times that of the human brain, with an imposing volume of eight thousand cubic centimeters! They’re also known to express obvious emotions. What would they say to use if we could somehow crack the sperm whale language code? Would they beg us to remove our rubbish from their habitat? Would they appeal to our better angels?

Identifying the Enemies

Sperm whales eat mostly “garden variety” squid, less than a foot in length, but in an ironic twist, their worst enemy is thought to be the giant squid. These colossal squid are usually between ten to thirteen metres (33 to 43 feet). Serrated sucker scars from these ginormous squid are often found on sperm whale bodies. While sperm whales may eat these giant squid, they put up a good fight at minimum and may even be able to kill, or at least harm significantly, a sperm whale at times.

However, the rubbish clearance that we as humans fill our oceans with cause more damage to sperm whales than all the giant squid in the world. We must face the hard reality that our rubbish clearance is directly responsible for the death of sperm whales, and many other marine mammals, and many other animal species for that matter. We must own up to that fact and start seriously working toward finding solutions.

If you have pictures of sperm whales, please send them to Clearabee’s Facebook page in honor of the most recent sperm whale death at the hands of our rubbish clearance. Clearabee is the leading on demand rubbish clearance company in the UK. Clearabee is very supportive of conservation projects that involve protecting our planet and wildlife from the destructive forces of our rubbish clearance.

Analysis of Agro Biomass Projects

The current use of agro biomass for energy generation is low and more efficient use would release significant amounts of agro biomass resources for other energy use. Usually, efficiency improvements are neglected because of the non-existence of grid connections with agro-industries.

Electricity generated from biomass is more costly to produce than fossil fuel and hydroelectric power for two reasons. First, biomass fuels are expensive. The cost of producing biomass fuel is dependent on the type of biomass, the amount of processing necessary to convert it to an efficient fuel, distance to the energy conversion plant, and supply and demand for fuels in the market place. Biomass fuel is low-density and non-homogeneous and has a small unit size.

Consequently, biomass fuel is costly to collect, process, and transport to facilities.  Second, biomass-to-energy facilities are much smaller than conventional fossil fuel-based power plants and therefore cannot produce electricity as cost-effectively as the fossil fuel-based plants.

Agro biomass is costly to collect, process, and transport to facilities.

The biomass-to-energy facilities are smaller because of the limited amount of fuel that can be stored at a single facility. With higher fuel costs and lower economic efficiencies, solid-fuel energy is not economically competitive in a deregulated energy market that gives zero value or compensation for the non-electric benefits generated by the biomass-to-energy industry.

Biomass availability for fuel usage is estimated as the total amount of plant residue remaining after harvest, minus the amount of plant material that must be left on the field for maintaining sufficient levels of organic matter in the soil and for preventing soil erosion. While there are no generally agreed-upon standards for maximum removal rates, a portion of the biomass material may be removed without severely reducing soil productivity.

Technically, biomass removal rates of up to 60 to 70 percent are achievable, but in practice, current residue collection techniques generally result in relatively low recovery rates in developing countries. The low biomass recovery rate is the result of a combination of factors, including collection equipment limitations, economics, and conservation requirements. Modern agricultural equipment can allow for the joint collection of grain and residues, increased collection rates to up to 60 percent, and may help reduce concerns about soil compaction.

Manage Trees With Sustainability In Mind

There is growing concern as forest land outside of conservation areas is steadily decreasing. There has been a disturbing reduction in primary forests of 40 million hectares in the last decade. The total area of forest within protected areas has increased by 94 million hectares in the past two decades and now accounts for 13% of the total of forests globally.

Tree healthcare for humans

Trees are well known for providing oxygen as a result of their photosynthesis process.  It is in fact the carbon dioxide (CO2) that is removed during this process therefore helping to mitigate the negative effects of burning fossil fuels ie. CO2 production.  The benefits to the world of this process make the existence and importance of the Amazon rainforest especially significant.

Trees benefit cities too

Not only are trees a beautiful addition to any city, they also serve a practical purpose by absorbing pollutants.  Their presence makes a city appear more vibrant and more friendly.  For example, San Francisco is home to 105,000 trees.  Tree planting should be kept in pace with tree mortality and removals.  A tree management plan is essential to ensure sustainability.

Tree management for woodland

Trees should be checked for health and also for the merchantability of the trees.  When areas of the woodland require thinning out it is useful to produce a product that has a commercial value.  This way waste management has been prioritized and has turned a Liability into an Asset.  The harvested wood/logs can be considered an asset and can be sold as fuel.  Always ensure trees are removed when over-crowding is an issue to allow for tree growth of the remaining trees.  The woodland is sustainable by including sufficient planting of new trees.

Maintaining the urban trees

Your arborist can advise you of local procedures and the law regarding your trees which if not properly managed can become a legal liability.  Some types of trees do not take well to heavy pruning, for example the Southern Live Oak is best not located in restricted areas where heavy pruning to clear avenues may be required.  It is better to grow it in a larger landscaped area where it can grow with minimal pruning.  They often reach 60 to 80 feet in height with a 60 to 100 foot spread.

The branches of Live Oak tend to droop as they grow so some careful pruning will be necessary especially as this type of growth can be a problem for vehicular or pedestrian clearance beneath.  Many trees are not permitted to be removed without obtaining a tree removal permit first.  This is good as it provides some protection for the trees.

Other tree varieties to grow with sustainability

The beautiful red maple is a great yard tree being very tolerant and is able to grow in nearly any conditions but especially in acid to neutral soils.  Plant away from paths etc as the roots can raise sidewalks if too close.  A good layer of organic mulch should be placed around the roots to feed and help retain moisture.

Presence of trees make a city appear more vibrant and eco-friendly

Another commonly found tree in the US is the Loblolly Pine.  When found in plantations it provides the perfect habitat for wildlife such as deer, squirrels making it a very sustainable choice.  Being a faster growing tree it requires more regular pruning.

Enjoy our future with sustainability for trees

Sustainability ensures we leave the world in a good state for future generations to enjoy, whilst still meeting the needs of the current population.  Keep your trees maintained moving forward and always pay attention to the type of tree and manage accordingly.  This way you can enjoy the many beautiful trees around you.

Bioenergy Developments in Malaysia

Malaysia is blessed with abundant renewable sources of energy, especially biomass and solar. Under the Eighth Malaysian Plan, renewable energy was added in the energy mix to unveil a Five-Fuel Strategy to achieve 5 percent contribution by 2005.

Among the various sources of renewable energy, bioenergy seems to be the most promising option for Malaysia. The National Biofuel Policy, launched in 2006 encourages the use of environmentally friendly, sustainable and viable sources of biomass energy. Under the Five Fuel Policy, the government of Malaysia has identified biomass as one of the potential renewable energy. Malaysia produces atleast 168 million tonnes of biomass, including timber and oil palm waste, rice husks, coconut trunk fibres, municipal waste and sugar cane waste annually. Being a major agricultural commodity producer in the region Malaysia is well positioned amongst the ASEAN countries to promote the use of biomass as a renewable energy source.

Malaysia has been one of the world’s largest producers and exporters of palm oil for the last forty years. The Palm Oil industry, besides producing Crude Palm Oil (CPO) and Palm Kernel Oil, produces Palm Shell, Press Fibre, Empty Fruit Bunches (EFB), Palm Oil Mill Effluent (POME), Palm Trunk (during replanting) and Palm Fronds (during pruning).

Malaysia has approximately 4 million hectares of land under oil palm plantation. Over 75% of total area planted is located in just four states, Sabah, Johor, Pahang and Sarawak, each of which has over half a million hectares under cultivation. The total amount of processed FFB (Fresh Fruit Bunches) was estimated to be 75 million tons while the total amount of EFB produced was estimated to be 16.6 million tons. Around 58 million tons of POME is produced in Malaysia annually, which has the potential to produce an estimated 15 billion m3 of biogas can be produced each year.

Malaysia is the world’s second largest producer of crude palm oil. Almost 70% of the volume from the processing of fresh fruit bunch is removed as wastes in the form of empty fruit bunches, palm kernel shells, palm oil mill effluent etc. With more than 423 mills in Malaysia, this palm oil industry generated around 80 million dry tonnes of biomass in 2010. Malaysia has more than 2400 MW of biomass and 410 MW of biogas potential, out of which only 773MW has been harnessed until 2011.

Rice husk is another important agricultural biomass resource in Malaysia with good potential for power cogeneration. An example of its attractive energy potential is biomass power plant in the state of Perlis which uses rice husk as the main source of fuel and generates 10 MW power to meet the requirements of 30,000 households. The US$15 million project has been undertaken by Bio-Renewable Power Sdn Bhd in collaboration with the Perlis state government, while technology provider is Finland’s Foster Wheeler Energia Oy.

Under the EC-ASEAN Cogeneration Program, there are three ongoing Full Scale Demonstration Projects (FSDPs) – Titi Serong, Sungai Dingin Palm Oil Mill and TSH Bioenergy – to promote biomass energy systems in Malaysia. The 1.5MW Titi Serong power plant, located at Parit Buntar (Perak), is based on rice husk while the 2MW Sungai Dingin Palm Oil Mill project make use of palm kernel shell and fibre to generate steam and electricity. The 14MW TSH Bioenergy Sdn Bhd, located at Tawau (Sabah), is the biggest biomass power plant in Malaysia and utilizes empty fruit bunches, palm oil fibre and palm kernel shell as fuel resources.

An Introduction to Biomethane

Biogas that has been upgraded by removing hydrogen sulphide, carbon dioxide and moisture is known as biomethane. Biomethane is less corrosive than biogas, apart from being more valuable as a vehicle fuel. The typical composition of raw biogas does not meet the minimum CNG fuel specifications. In particular, the COand sulfur content in raw biogas is too high for it to be used as vehicle fuel without additional processing.

Liquified Biomethane

Biomethane can be liquefied, creating a product known as liquefied biomethane (LBM). Biomethane is stored for future use, usually either as liquefied biomethane or compressed biomethane (CBM) or  since its production typically exceeds immediate on-site demand.

Two of the main advantages of LBM are that it can be transported relatively easily and it can be dispensed to either LNG vehicles or CNG vehicles. Liquid biomethane is transported in the same manner as LNG, that is, via insulated tanker trucks designed for transportation of cryogenic liquids.

Compressed Biomethane

Biomethane can be stored as CBM to save space. The gas is stored in steel cylinders such as those typically used for storage of other commercial gases. Storage facilities must be adequately fitted with safety devices such as rupture disks and pressure relief valves.

The cost of compressing gas to high pressures between 2,000 and 5,000 psi is much greater than the cost of compressing gas for medium-pressure storage. Because of these high costs, the biogas is typically upgraded to biomethane prior to compression.

Applications of Biomethane

The utilization of biomethane as a source of energy is a crucial step toward a sustainable energy supply. Biomethane is more flexible in its application than other renewable sources of energy. Its ability to be injected directly into the existing natural gas grid allows for energy-efficient and cost-effective transport. This allows gas grid operators to enable consumers to make an easy transition to a renewable source of gas. The diverse, flexible spectrum of applications in the areas of electricity generation, heat provision, and mobility creates a broad base of potential customers.

Biomethane can be used to generate electricity and heating from within smaller decentralized, or large centrally-located combined heat and power plants. It can be used by heating systems with a highly efficient fuel value, and employed as a regenerative power source in gas-powered vehicles.

Biomethane to Grid

Biogas can be upgraded to biomethane and injected into the natural gas grid to substitute natural gas or can be compressed and fuelled via a pumping station at the place of production. Biomethane can be injected and distributed through the natural gas grid, after it has been compressed to the pipeline pressure. In many EU countries, the access to the gas grid is guaranteed for all biogas suppliers.

One important advantage of using gas grid for biomethane distribution is that the grid connects the production site of biomethane, which is usually in rural areas, with more densely populated areas. This enables the gas to reach new customers. Injected biomethane can be used at any ratio with natural gas as vehicle fuel.

Biomethane is more flexible in its application than other renewable sources of energy.

The main barriers for biomethane injection are the high costs of upgrading and grid connection. Grid injection is also limited by location of suitable biomethane production and upgrading sites, which have to be close to the natural gas grid.

Several European nations have introduced standards (certification systems) for injecting biogas into the natural gas grid. The standards, prescribing the limits for components like sulphur, oxygen, particles and water dew point, have the aim of avoiding contamination of the gas grid or the end users. In Europe, biogas feed plants are in operation in Sweden, Germany, Austria, the Netherlands, Switzerland and France.

Sugarcane Trash as Biomass Resource

cane-trashSugarcane trash (or cane trash) is an excellent biomass resource in sugar-producing countries worldwide. The amount of cane trash produced depends on the plant variety, age of the crop at harvest and soil and weather conditions. Typically it represents about 15% of the total above ground biomass at harvest which is equivalent to about 10-15 tons per hectare of dry matter. During the harvesting operation around 70-80% of the trash is left in the field with 20-30% taken to the mill together with the sugarcane stalks as extraneous matter. Cane trash’s calorific value is similar to that of bagasse but has an advantage of having lower moisture content, and hence dries more quickly. Nowadays only a small quantity of this biomass is used as fuel, mixed with bagasse or by itself, at the sugar mill. The rest is burned in the vicinity of the dry cleaning installation, creating a pollution problem in sugar-producing nations.

Cane trash and bagasse are produced during the harvesting and milling process of sugarcane which normally lasts between 6 to 7 months. Cane trash can potentially be converted into heat and electrical energy. However, most of the trash is burned in the field due to its bulky nature and high cost incurred in collection and transportation. Cane trash could be used as an off-season fuel for year-round power generation at sugar mills. There is also a high demand for biomass as a boiler fuel during the sugar-milling season. Sugarcane trash can also converted in biomass pellets and used in dedicated biomass power stations or co-fired with coal in power plants and cement kilns.

Burning of cane trash creates pollution in sugar-producing countries

Burning of cane trash creates pollution in sugar-producing countries

Currently, a significant percentage of energy used for boilers in sugarcane processing is provided by imported bunker oil. Overall, the economic, environmental, and social implications of utilizing cane trash in the final crop year as a substitute for bunker oil appears promising. It represents an opportunity for developing biomass energy use in the Sugarcane industry as well as for industries / communities in the vicinity. Positive socio-economic impacts include the provision of large-scale rural employment and the minimization of oil imports. It can also develop the expertise necessary to create a reliable biomass supply for year-round power generation.

Recovery of Cane Trash

Recovery of cane trash implies a change from traditional harvesting methods; which normally consists of destroying the trash by setting huge areas of sugarcane fields ablaze prior to the harvest.  There are a number of major technical and economic issues that need to be overcome to utilize cane trash as a renewable energy resource. For example, its recovery from the field and transportation to the mill, are major issues. Alternatives include the current situation where the cane is separated from the trash by the harvester and the two are transported to the mill separately, to the harvesting of the whole crop with separation of the cane and the trash carried out at the mill. Where the trash is collected from the field it maybe baled incurring a range of costs associated with bale handling, transportation and storage. Baling also leaves about 10-20% (1-2 tons per hectare) of the recoverable trash in the field.

A second alternative is for the cane trash to be shredded and collected separately from the cane during the harvesting process. The development of such a harvester-mounted cane trash shredder and collection system has been achieved but the economics of this approach require evaluation. A third alternative is to harvest the sugarcane crop completely which would require an adequate collection, transport and storage system in addition to a mill based cleaning plant to separate the cane from the trash .

A widespread method for cane trash recovery is to cut the cane, chop into pieces and then it is blown in two stages in the harvester to remove the trash. The amount of trash that goes along with the cane is a function of the cleaning efficiency of the harvester. The blowers are adjusted to get adequate cleaning with a bearable cane loss.

On the average 68 % of the trash is blown out of the harvester, and stays on the ground, and 32 % is taken to the mill together with the cane as extraneous matter. The technique used to recover the trash staying on the ground is baling. Several baling machines have been tested with small, large, round and square bales. Cane trash can be considered as a viable fuel supplementary to bagasse to permit year-round power generation in sugar mills.

Thus, recovery of cane trash in developing nations of Asia, Africa and Latin America implies a change from traditional harvesting methods, which normally consists of destroying the trash by setting huge areas of cane fields ablaze prior to the harvest. To recover the trash, a new so-called “green mechanical harvesting” scheme will have to be introduced. By recovering the trash in this manner, the production of local air pollutants, as well as greenhouse gases contributing to adverse climatic change, from the fires are avoided and cane trash could be used as a means of regional sustainable development.

Cane Trash Recovery in Cuba

The sugarcane harvesting system in Cuba is unique among cane-producing countries in two important respects. First, an estimated 70 % of the sugarcane crop is harvested by machine without prior burning, which is far higher than for any other country. The second unique feature of Cuban harvesting practice is the long-standing commercial use of “dry cleaning stations” to remove trash from the cane stalks before the stalks are transported to the crushing mills.

Cuba has over 900 cleaning stations to serve its 156 sugar mills. The cleaning stations are generally not adjacent to the mills, but are connected to mills by a low-cost cane delivery system – a dedicated rail network with more than 7000 km of track. The cleaning stations take in green machine-cut or manually cut cane. Trash is removed from the stalk and blown out into a storage area. The stalks travel along a conveyor to waiting rail cars. The predominant practice today is to incinerate the trash at the cleaning station to reduce the “waste” volume.

Collection Systems for Agricultural Biomass

Biomass collection involves operations pertaining to gathering, packaging, and transporting biomass to a nearby site for temporary storage. The amount of biomass resource that can be collected at a given time depends on a variety of factors. In case of agricultural residues, these considerations include the type and sequence of collection operations, the efficiency of collection equipment, tillage and crop management practices, and environmental restrictions, such as the need to control soil erosion, maintain soil productivity, and maintain soil carbon levels.

The most conventional method for collecting biomass is baling which can be either round or square. Some of the important modern biomass collection operations have been discussed below:

Baling

Large square bales are made with tractor pulled balers. A bale accumulator is pulled behind the baler that collects the bales in group of 4 and leaves them on the field. At a later date when available, an automatic bale collector travels through the field and collects the bales.

The automatic bale collector travels to the side of the road and unloads the bales into a stack. If the automatic bale collector is not available bales may be collected using a flat bed truck and a front end bale loader. A loader is needed at the stack yard to unload the truck and stack the bales. The stack is trapped using a forklift and manual labor.

Loafing

When biomass is dry, a loafer picks the biomass from windrow and makes large stacks. The roof of the stacker acts as a press pushing the material down to increase the density of the biomass. Once filled, loafer transports the biomass to storage area and unloads the stack. The top of the stack gets the dome shape of the stacker roof and thus easily sheds water.

Dry Chop

In this system a forage harvester picks up the dry biomass from windrow, chops it into smaller pieces (2.5 – 5.0 cm). The chopped biomass is blown into a forage wagon traveling along side of the forage harvester. Once filled, the forage wagon is pulled to the side of the farm and unloaded. A piler (inclined belt conveyor) is used to pile up the material in the form of a large cone.

Wet Chop

Here a forage harvester picks up the dry or wet biomass from the windrow. The chopped biomass is blown into a forage wagon that travels along side of the harvester. Once filled, the wagon is pulled to a silage pit where biomass is compacted to produce silage.

Whole Crop Harvest

The entire material (grain and biomass) is transferred to a central location where the crop is fractionated into grain and biomass.  The McLeod Harvester developed in Canada fractionates the harvested crop into straw and graff (graff is a mixture of grain and chaff). The straw is left on the field. Grain separation from chaff and other impurities take place in a stationary system at the farmyard.

McLeod Harvester fractionates the harvested crop into straw and graff

For the whole crop baling, the crop is cut and placed in a windrow for field drying. The entire crop is then baled and transported to the processing yard. The bales are unwrapped and fed through a stationary processor that performs all the functions of a normal combine. Subsequently, the straw is re-baled.