Energy Value of Agricultural Wastes

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

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

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

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

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

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

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

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

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

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

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

How Farmers Can Benefit from Agriculture Recruiting?

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

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1. Research

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

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

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

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

2. Business Management Consulting

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

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

3. Soil Testing

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

4. Seed Selection

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

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5. Expert Damage Control

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

6. Pest Management

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

Conclusion

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

3 Ways to Reuse Water Using Renewable Energy

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

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

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

1. Anaerobic Digestion

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

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

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

2. Vapor Compression Distillation

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

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

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

3. Solar Distillation

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

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

Environmental and Economic Benefits

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

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

Biogas Prospects in Rural Areas: Perspectives

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

What is Biogas?

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

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

Biogas Prospects in Rural Areas

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

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

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

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

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

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

Benefits of Biogas for Rural Areas

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

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

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

What Can We Do?

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

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

Agricultural Biomass in Malaysia

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

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

Palm Oil Industry

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

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

Sugar Industry

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

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

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