Tag Archives: crop wastes

Importance of Biomass Energy

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Biomass energy has rapidly become a vital part of the global renewable energy mix and account for an ever-growing share of electric capacity added worldwide. Renewable energy supplies around one-fifth of the final energy consumption worldwide, counting traditional biomass, large hydropower, and “new” renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels).

Traditional biomass, primarily for cooking and heating, represents about 13 percent and is growing slowly or even declining in some regions as biomass is used more efficiently or replaced by more modern energy forms. Some of the recent predictions suggest that biomass energy is likely to make up one third of the total world energy mix by 2050. Infact, biofuel provides around 3% of the world’s fuel for transport.

biomass_feedstock

Biomass energy resources are readily available in rural and urban areas of all countries. Biomass-based industries can foster rural development, provide employment opportunities and promote biomass re-growth through sustainable land management practices.

The negative aspects of traditional biomass utilization in developing countries can be mitigated by promotion of modern waste-to-energy technologies which provide solid, liquid and gaseous fuels as well as electricity. Biomass wastes encompass a wide array of materials derived from agricultural, agro-industrial, and timber residues, as well as municipal and industrial wastes.

The most common technique for producing both heat and electrical energy from biomass wastes is direct combustion. Thermal efficiencies as high as 80 – 90% can be achieved by advanced gasification technology with greatly reduced atmospheric emissions.

Combined heat and power (CHP) systems, ranging from small-scale technology to large grid-connected facilities, provide significantly higher efficiencies than systems that only generate electricity. Biochemical processes, like anaerobic digestion and sanitary landfills, can also produce clean energy in the form of biogas and producer gas which can be converted to power and heat using a gas engine.

Advantages of Biomass Energy

Bioenergy systems offer significant possibilities for reducing greenhouse gas emissions due to their immense potential to replace fossil fuels in energy production. Biomass reduces emissions and enhances carbon sequestration since short-rotation crops or forests established on abandoned agricultural land accumulate carbon in the soil.

Bioenergy usually provides an irreversible mitigation effect by reducing carbon dioxide at source, but it may emit more carbon per unit of energy than fossil fuels unless biomass fuels are produced unsustainably.

Biomass can play a major role in reducing the reliance on fossil fuels by making use of thermochemical conversion technologies. In addition, the increased utilization of biomass-based fuels will be instrumental in safeguarding the environment, generation of new job opportunities, sustainable development and health improvements in rural areas.

The development of efficient biomass handling technology, improvement of agro-forestry systems and establishment of small and large-scale biomass-based power plants can play a major role in rural development. Biomass energy could also aid in modernizing the agricultural economy.

Consistent and reliable supply of biomass is crucial for any biomass project

When compared with wind and solar energy, biomass power plants are able to provide crucial, reliable baseload generation. Biomass plants provide fuel diversity, which protects communities from volatile fossil fuels. Since biomass energy uses domestically-produced fuels, biomass power greatly reduces our dependence on foreign energy sources and increases national energy security.

A large amount of energy is expended in the cultivation and processing of crops like sugarcane, coconut, and rice which can met by utilizing energy-rich residues for electricity production.

The integration of biomass-fueled gasifiers in coal-fired power stations would be advantageous in terms of improved flexibility in response to fluctuations in biomass availability and lower investment costs. The growth of the bioenergy industry can also be achieved by laying more stress on green power marketing.

Biomass Energy Potential in Pakistan

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

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

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

Biomass Energy in Pakistan

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

Agricultural Residues

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

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

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

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

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

Animal Manure

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

Municipal Solid Waste

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

Bioenergy in the Middle East

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

MENA_Bioenergy

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

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

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

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

date-wastes

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

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

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

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

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

Biomass Exchange – Key to Success in Biomass Projects

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Biomass exchange is emerging as a key factor in the progress of biomass energy sector. It is well-known that the supply chain management in any biomass project is a big management conundrum. The complexity deepens owing to the large number of stages which encompass the entire biomass value chain. It starts right from biomass resource harvesting and goes on to include biomass collection, processing, storage and eventually its transportation to the point of ultimate utilization.

biomass-exchange

Owing to the voluminous nature of the resource, its handling becomes a major issue since it requires bigger modes of biomass logistics, employment of a larger number of work-force and a better storage infrastructure, as compared to any other fuel or feedstock. Not only this their lower energy density characteristic, makes it inevitable for the resource to be first processed and then utilized for power generation to make for better economics.

All these problems call for a mechanism to strengthen the biomass value chain. This can be done by considering the following:

  • Assuring a readily available market for the resource providers or the producers
  • Assuring the project developers of a reliable chain and consistent feedstock availability
  • Awareness to the project developer of the resources in closest proximity to the plant site
  • Assurance to the project developer of the resource quality
  • Timely pick-up and drop of resource
  • Proper fuel preparation as per technology requirements
  • Removal of intermediaries involved in the process – to increase value for both, the producers as well as the buyers
  • No need for long term contracts (Not an obligation)
  • Competitive fuel prices
  • Assistance to producers in crop management

Biomass Exchange Model

The figure below gives a general understanding of how such a model could work, especially in the context of developing nations where the size of land holdings is usually small and the location of resources is scattered, making their procurement a highly uneconomic affair. This model is commonly known as Biomass Exchange

In such a model, the seed, fertilizer shops and other local village level commercial enterprises could be utilized as an outreach or marketing platform for such a service.  Once the producer approves off the initial price estimate, as provided by these agencies, he could send a sample of the feedstock to the pre-deputed warehouses for a quality check.

These warehouses need to be organized at different levels according to the village hierarchy and depending on the size, cultivated area and local logistic options available in that region. On assessing the feedstock sample’s quality, these centers would release a plausible quote to the farmer after approving which, he would be asked to supply the feedstock.

On the other hand, an entity in need of the feedstock would approach the biomass exchange, where it would be appraised of the feedstock available in the region near its utilization point and made aware of the quantity and quality of the feedstock. The entity would then quote a price according to its suitability which would be relayed to the primary producer.

An agreement from both the sides would entail the placement of order and the feedstock’s subsequent processing and transportation to the buyer’s gate. The pricing mechanisms could be numerous ranging from, fixed (according to quality), bid-based or even market-driven.

Roadblocks

The hurdles could be in the form of the initial resource assessment which could in itself be a tedious and time consuming exercise. Another roadblock could be in the form of engaging the resource producers with such a mechanism. Since these would usually involve rural landscapes, things could prove to be a little difficult in terms of implementation of initial capacity building measures and concept marketing.

Benefits

The benefits of  a biomass exchange are enumerated below:

  • Support to the ever increasing power needs of the country
  • Promotion of biomass energy technologies
  • Development of rural infrastructure
  • Increased opportunities for social and micro-entrepreneurship
  • Creation of direct and indirect job opportunities
  • Efficient utilization of biomass wastes
  • Potential of averting millions of tonnes of GHGs emissions

Conclusions

In India alone, there has been several cases where biomass power projects of the scale greater than 5 MW are on sale already, even with their power purchase agreements still in place. Such events necessitate the need to have a mechanism in place which would further seek the promotion of such technologies.

Biomass Exchange is an attractive solution to different problems afflicting biomass projects, at the same time providing the investors and entrepreneurs with a multi-million dollar opportunity. Although such a concept has been in existence in the developed world for a long time now, it has not witnessed many entrepreneurial ventures in developing nations where the need to strengthen the biomass supply chain becomes even more necessary.

However, one needs to be really careful while initiating such a model since it cannot be blindly copied from Western countries owing to entirely different land-ownership patterns, regional socio-political conditions and economic framework. With a strong backup and government support, such an idea could go a long way in strengthening the biomass supply chain, promotion of associated clean energy technologies and in making a significant dent in the present power scenario in the developing world.

Rationale for Biomass Supply Chain

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Biomass resources have been in use for a variety of purposes since ages. The multiple uses of biomass includes usage as a livestock or for meeting domestic and industrial thermal requirements or for the generation of power to fulfill any electrical or mechanical needs. One of the major issues, however, associated with the use of any biomass resources is its supply chain management. The resource being bulky, voluminous and only seasonally available creates serious hurdles in the reliable supply of the feedstock, regardless of its application. The idea is thus to have something which plugs in this gap between the biomass resource availability and its demand.

The Problem

The supply chain management in any biomass based project is nothing less than a big management conundrum. The complexity deepens owing to the large number of stages which encompass the entire biomass value chain. It starts right from the resource harvesting and goes on to include the resource collection, processing, storage and eventually its transportation to the point of ultimate utilization.

Owing to the voluminous nature of the resource, its handling becomes a major issue since it requires bigger modes of logistics, employment of a larger number of work-force and a better storage infrastructure, as compared to any other fuel or feedstock. Not only this their lower energy density characteristic, makes it inevitable for the resource to be first processed and then utilized for power generation to make for better economics.

All these hassles associated with such resources, magnify the issue of their utilization when it comes to their supply chain. The seasonal availability of most of the biomass resources, alternative application options, weather considerations, geographical conditions and numerous other parameters make it difficult for the resource to be made consistently available throughout the year. This results in poor feedstock inputs at the utilization point which ends up generating energy in a highly erratic and unreliable manner.

The Solution

Although most of the problems discussed above, are issues inherently associated with the usage of biomass resources, they can be curtailed to a larger extent by strengthening the most important loophole in such projects – The Biomass Resource Supply Chain.

World over, major emphasis has been laid in researching upon the means to improve the efficiencies of such technologies. However, no significant due diligence has been carried out in fortifying the entire resource chain to assure such plants for a continuous resource supply.

The usual solution to encounter such a problem is to have long term contracts with the resource providers to not only have an assured supply but also guard the project against unrealistic escalations in the fuel costs. Although, this solution has been found to be viable, it becomes difficult to sustain such contracts for longer duration since these resources are also susceptible to numerous externalities which could be in the form of any natural disaster, infection from pests or any other socio-political or geographical disturbances, which eventually lead to an increased burden on the producers.

Logistics of a Biopower Plant

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Biomass feedstock logistics encompasses all of the unit operations necessary to move biomass feedstock from the land to the energy plant and to ensure that the delivered feedstock meets the specifications of the conversion process. The packaged 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 biorefinery 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 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 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 biomass power 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.

How is Biomass Transported

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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 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.

A biomass freight train in England

Transportation costs of low-density and high-moisture agricultural residues straw 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. Pre?processing equipment may be used to densify biomass, increasing truck payloads and reducing transportation costs over longer haul distances.