Category Archives: Biomass Energy

6 Reasons Wood Stove Sales Are Taking Off

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Why are wood burning stoves selling like crazy? Most assume it’s the sustainability factor of energy-efficient stoves. But there’s more to the new surge of interest in them than that. Yes, biomass stoves offer an efficient way to produce heat, but they also look great, are affordable, and come in a huge variety of styles. Consumers can select dozens of additional features like temperature control, slow cooldown mode, smoke-free operation, and more. If you’re on the fence about investing in a wood stove, consider the following points before making a final decision.

benefits of wood burning stoves

1. They’re Efficient

Like so many other forms of biomass energy generation, wood burning stoves are highly efficient, both in terms of heat production and cost. For homeowners who are accustomed to relying on electricity for heating their homes, the pleasant surprise is that it costs less to produce the same amount of heat from a wood-burning stove. That holds true whether the fuel is wood you collect yourself, bundles purchased from a local store, or condensed pellets.

2. Homeowners Can Borrow to Pay for the Project

While most single units are competitively priced, many homeowners decide to install several stoves in their living spaces, sometimes one in each large room. But even those who opt for just one unit can do themselves a favor by paying for the environmental upgrade with a personal loan. It’s true that some dealers offer financing, but in nearly every case, you can get much more competitive rates and terms by taking out a personal loan to cover the expense of purchasing a wood stove, the ultimate bioenergy household appliance, and heating source.

Consider shopping as a first step. That way, you’ll get an accurate idea about price ranges, features, and what you want to spend. Then, when applying for a loan, aim to borrow about 10% more than what you expect to spend on the stove. The strategy makes perfect sense because the final price tag will be slightly higher than you first predicted after taxes, installation, and a few extra supplies.

3. The Units Look Great

Most discussions about biomass energy focus on statistical comparisons between products like wood-based home heating units and electrical home furnace units. But too often, overlook one of the primary advantages of wood stove units: They have a unique, attractive look that improves the overall appearance of any home. Spend a few minutes exploring some of the latest models on the major sellers’ websites. It soon becomes obvious that these old-fashioned appliances add a dose of elegance and emotional warmth to rooms of any size.

4. Power Outage? No Problem

Rolling power outages, a term that is a euphemism for planned grid breakdowns, are the bane of the modern era. In places like California and elsewhere, states are cutting electricity to millions of homes because state regulators are unable to manage the demand on grids. For homeowners who have a backup source of heat, outages are a minor inconvenience. In fact, many biofuel enthusiasts prefer to use wood burning appliances as a first line of heat generation. For many others, the units serve as reliable heat in times of state mismanagement of electrical power.

5. Buyers Can Test the Units Before Buying

Manufacturers and retail merchants offer various arrangements for first-time buyers. It’s possible for homeowners to pay a small rental fee for a basic unit, use it for a few months, and decide whether they want to make it a permanent part of their household energy array. These trial periods are popular with people who have no prior experience with bioenergy devices.

6. Newer Models are Safer, More Efficient, and Cost Less

Since 2000, there has been a great deal of advancement in the science of heat conservation in biomass stoves. Not only are the latest models less costly than older versions, but they deliver much higher heating ratios per unit burned. One reason prices have come down significantly is higher production levels due to increased consumer demand. When producers build many thousands of units per year and sell them quickly, they achieve economies of scale and can cut prices.

Likewise, the many technological breakthroughs in science have contributed to the higher efficiency levels of new biomass stoves. For consumers, that means not just more competitive pricing and higher quality but a wider range of selections from sellers.

Bioethanol Sector in India: Major Challenges To Overcome

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Global demand for fuel efficiency, environmental quality and energy security have elicited global attention towards liquid biofuels, such as bioethanol and biodiesel. Around the world, governments have introduced various policy measurements, mandatory fuel blending programmes, incentives for flex fuel vehicles and agricultural subsidies for the farmers.

In India, the government launched Ethanol Blended Petrol (EBP) programme in January 2013 for 5% ethanol blended petrol. The policy had significant focus on India’s opportunity to agricultural and industrial sectors with motive of boosting biofuel (bioethanol and biodiesel) usage and reducing the existing dependency on fossil fuel.

bioethanol india

The Government of India initiated significant investments in improving storage and blending infrastructure. The National Policy on Biofuels has set a target of 20% blending of biofuel by 2017. However, India has managed to achieve only 5% by September 2016 due to certain technical, market and regulatory hurdles.

In India, sugarcane molasses is the major resource for bioethanol production and inconsistency of raw material supply holds the major liability for sluggish response to blending targets.  Technically speaking, blend wall and transportation-storage are the major challenges towards the biofuel targets. Blending wall is the maximum percent of ethanol that can be blended to fuel without decreasing the fuel efficiency.

Various vehicles are adaptable to various blending ratio based on the flexibility of engines. The technology for the engine modification for flex fuel is not new but making the engines available in India along with the supply chain and calibrating the engine for Indian conditions is the halting phase. The commonly used motor vehicles in the country are not effectual with flex fuel.

Sugarcane molasses is the most common feedstock for bioethanol production in India

Sugarcane molasses is the most common feedstock for bioethanol production in India

Ethanol being a highly flammable liquid marks obligatory safety and risk assessment measures during all phases of production, storage and transportation. The non-uniform distribution of raw material throughout the country, demands a compulsory transportation and storage, especially inter-state movement, encountering diverse climatic and topographic conditions.

Major bioethanol consumers in India are potable liquor sector (45%), alcohol based chemical industry (40%), the rest for blending and other purposes. The yearly profit elevation in major sectors is a dare to an economical ethanol supply for Ethanol Blending Programme. Drastic fluctuation in pricing of sugar cane farming and sugar milling resulted to huge debt to farmers by mill owners. Gradually the farmers shifted from sugarcane cultivation other crops.

Regulatory and policy approaches on excise duty on storage and transportation of ethanol and pricing strategy of ethanol compared to crude oil are to be revised and implemented effectively. Diversifying the feedstocks (especially use of lignocellulosic biomass) and advanced technology for domestic ethanol production in blending sectors are to be fetched out from research laboratories to commercial scale. Above all the knowledge of economic and environmental benefits of biofuel like reduction in pollutants and import bills and more R&D into drop-in biofuels, need to be amplified for the common man.

How to Reduce the Establishment Costs of Miscanthus

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Miscanthus has been lauded as a dynamic high potential biomass energy crop for some time now due to its high yields, low input requirements and perennial nature. Miscanthus is commonly used as a biomass fuel to produce heat and electricity through combustion, but studies have found that miscanthus can produce similar biogas yields to maize when harvested at certain times of the year.  Miscanthus is a C4 grass closely related to maize and sugarcane, it can grow to heights of three metres in a single growing season.

Miscanthus-Elephant-Grass

High Establishment Costs

However, The high cost of growing miscanthus has impeded its popularity. High establishment costs of miscanthus are as a result of the sterile nature of the crop, which means that miscanthus cannot be propagated from seed and instead must be propagated from vegetative material.

The vegetative material commonly used is taken from the root structure known as rhizomes; rhizome harvesting is a laborious process and when combined with low multiplication rates, results in a high cost for miscanthus rhizomes. The current figure based on Irish figures is €1,900 ha for rhizomes.

Promising Breakthrough

Research conducted in Teagasc Oak Park Carlow Ireland, suggests that there may be a cost effective of method of propagating miscanthus by using the stem as the vegetative material rather than having to dig up expensive rhizomes. The system has been proven in a field setting over two growing seasons and plants have been shown to be perennial.

A prototype miscanthus planter suitable for commercial up scaling has been developed to sow stem segments of miscanthus. Initial costs are predicted at €130 ha for plant material. The image below shows the initial stem that was planted in a field setting and the shoots, roots, and rhizome developed by the stem at the end of the first growing season.

miscanthus-stem

Feedstock for AD Plants

Switching from maize to miscanthus as a feedstock for anaerobic digestion plants would increase profitability and boost the GHG abatement credentials of the systems. Miscanthus is a perennial crop which would provide a harvest every year once established for 20 years in a row without having to be replanted compared to maize which is replanted every year. This would provide an obvious economic saving as well as allowing carbon sequestration in the undisturbed soil.

There would be further GHG savings from the reduced diesel consumption required for the single planting as opposed to carrying out heavy seedbed cultivation each year for maize. Miscanthus harvested as an AD feedstock would also alleviate soil compaction problems associated with maize production through an earlier harvest in more favourable conditions.

Future Perspectives

Miscanthus is a nutrient efficient crop due to nutrient cycling. With the onset of senescence nutrients in the stem are transferred back to the rhizome and over-wintered for the following year’s growth. However the optimum date to harvest biomass to produce biogas is before senescence.

This would mean that a significant proportion of the plants nutrient stores would be removed which would need to be replaced. Fertiliser in the form of digestate generated from a biogas plant could be land spread to bridge nutrient deficiencies. However additional more readily available chemical N fertiliser may have to be applied.

Some work at Oak Park on September harvested miscanthus crops has seen significant responses from a range of N application rates. With dwindling subsidies to support anaerobic digestion finding a low cost perennial high yielding feedstock could be key to ensuring economic viability.

Biomass Energy in Nigeria: An Overview

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Oil and gas accounts for over 70% of energy consumed in Nigeria, according to the World Bank. Considering this dependency on fossil oil and possibility of it running out in the future, there should be an urgent intervention to look into other ways to generate energy in Nigeria. The world is moving away gradually from fossil oil and aligning towards sustainable energy resources to substitute conventional fuel, Nigeria should not be exempted from this movement. Biomass, a popular form of renewable energy, is considered as a credible and green alternative source of energy which many developed and developing countries have been maximizing to its potential.

biomass-sustainability

Power generation and supply have been inadequate in Nigeria. This inadequacy of power limits human, commercial and industrial productivity and economic growth . What is the use of infrastructure without constant electricity? Even God created light first. Sustainable and constant supply of power should be one of the priority of government in nation development. Investing in biomass energy will cause an increase in the amount of power generated in Nigeria. Infact, biomass energy has the potential to resolve the energy crisis in the country in the not so distant future.

What is Biomass

The word biomass refers to organic matter (mainly plants) which acts as a source of sustainable and renewable energy. It is a renewable energy source because the plants can be replaced as oppose to the conventional fossil fuel which is not renewable. Biomass energy is a transferred energy from the sun; plants derives energy from the sun through photosynthesis which is further transferred through the food chain to animals’ bodies and their waste.

Biomass has the potential to provide an affordable and sustainable source of energy, while at the same time help in curbing the green house effect. In India the total biomass generation capacity is 8,700 MW according to U.S. of Commerce’s International Trade Administration, whereas the generating capacity in U.S. is 20,156  MW with 178 biomass power plants, according to Biomass Magazine.

Power Sector in Nigeria

Unfortunately, the total installed electricity capacity generated in Nigeria is 12,522 MW, well below the current demand of 98,000MW . The actual output is about 3,800MW, resulting in a demand shortfall of 94,500MW throughout the country. As a result of this wide gap between demand and output, only 45% of Nigeria’s population has access to electricity. Renewable energy contributed 19% of total electricity generated in Nigeria out of which biomass contribution is infinitesimal.

Electricity generation for Nigeria’s grid is largely dominated by two sources; non-renewable thermal (natural gas and coal) and renewable (hydro). Nigeria depends on non-renewable energy despite its vast potential in renewable sources such as solar, wind, biomass and hydro. The total potential of these renewables is estimated at over 68,000MW, which is more than five times the current power output.

Biomass Resources in Nigeria

Biomass can come in different forms like wood and wood waste, agriculture produce and waste, solid waste.

1. Wood

Electricity can be generated with wood and wood product/waste(like sawdust) in modern day through cogeneration, gasification or pyrolysis.

2. Agriculture Residues

In Nigeria, 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.

3. Municipal Solid Waste

Back then in secondary school, I learnt that gas could be tapped from septic tank which could further be used for cooking.  Any organic waste (like animal waste, human waste) when decomposed by anaerobic microorganisms releases biogas which can be tapped and stored for either cooking or to generate electricity.

Biomass can be used to provide heat and electricity as well as biofuel and biogas for transport. There are enough biomass capacity to meet our demand for electricity and other purposes. From climatic point of view, there is a warm climate in Nigeria which is a good breeding ground for bacteria to grow and decompose the wastes. There are plant and animal growth all year round which in turn create waste and consequently produce biomass.

In November 2016, The Ebonyi State Government  took over  the United Nations Industrial Development Organization (UNIDO) demonstration biomass gasifier power plant located at the UNIDO Mini -industrial cluster in Ekwashi Ngbo in Ohaukwu Local Government Area of the State. The power plant is to generate 5.5 Megawatt energy using rice husk and other available waste materials available. More of these type of power plants and commitment are needed to utilize the potential of biomass fully.

Why Biomass Energy?

Since biomass makes use of waste to supply energy, it helps in waste management. It also has the potential to supply more energy (10 times) than the one produced from sun and wind. Biomass energy in Nigeria will lead to increase in revenue generation and conserves our foreign exchange. Increase in energy generation will yield more productivity for industries and the rate at which they are shutting down due to the fact that they spend more on power will be reduced to minimal.

Many local factories/companies will spring up and foreign investors will be eager to invest in Nigeria with little concern about power. Establishment of biopower plants will surely create more jobs and indirectly reduce the number of people living in poverty which is increasing everyday at an alarming rate.

Africa’s most populous country needs more than 10 times its current electricity output to guarantee supply for its 198 million people – nearly half of whom have no access at all, according to power minister Babatunde Fashola. Biomass energy potential in Nigeria is promising –  with heavy investment, stake holder cooperation and development of indigenous technologies. The deployment of large-scale biomass energy systems will not only significantly increase Nigeria’s electricity capacity but also ease power shortages in the country.

Bioenergy with Carbon Capture and Storage: Role in Climate Mitigation

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With increasing concern and awareness of climate change, there has been a growth in the renewable energy sector through government subsidies and private investment, allowing for the replacement of current sources of energy with less carbon-intensive fuels. However, renewable energy technologies are yet to topple the traditional fossil fuel-powered electricity market. With the increasing trajectory of global emissions, climate research has been exploring other methods of climate mitigation, for instance, through the use of large-scale geoengineering technologies.

Biomass-Resources

A quick glance at popular biomass resources

Of particular focus are the carbon dioxide removal techniques, namely Carbon Capture and Storage (CCS) and Bioenergy with Carbon Capture and Storage (BECCS) that have been prominently featured in emission scenarios of climate models, particularly for their direct influence in reducing carbon dioxide emissions.

CCS involves capturing carbon dioxide emissions from industries and storing them under geological reservoirs either on shore or offshore. You can read more about this technology on a previous EcoMENA article.

What is Bioenergy with Carbon Capture and Storage

One of the main concerns about CCS is the use of fossil fuels for its operations. In the pursuit for greener climate mitigation technologies, Bioenergy with Carbon Capture and Storage (BECCS) has emerged as a climate saviour, featuring in prominent emissions scenarios and climate models to achieve the 1.5-degree target.

In the place of fossil fuels, biomass is instead used as the primary fuel source for BECCS as seen in the picture below. The two-step absorption of carbon dioxide, first during the growth of the biomass, and second through capturing of the biomass emissions, makes BECCS, in theory, a net negative emissions technique.

Source: Can we deploy enough BECCS to achieve climate targets? AVOID 2

Of the 116 climate scenarios suggested by the IPCC, BECCS was seen to have a significant role in 101 of the scenarios to help prevent global temperature rise above the 1.5-degree target. In fact, UK electricity generator Drax, has chosen to invest in the BECCS technology and started its first trial earlier this year, making it the first of its kind in Europe.

Risks associated with BECCS

While the combination of bioenergy and CCS provides an ideal carbon negative mitigation strategy, it also combines the existing risks associated with both technologies. In addition to lack of investment and long-term economic policies for CCS, large scale deployment of BECCS is hindered by uncertainties such as land, water and resource availability. Studies have shown concerns regarding the carbon intensity and the scale of land and resources required to sustain the bioenergy component required for BECCS.

While the net negative aspect of BECCS may work in theory, studies have revealed significant proportions of emissions associated with indirect land use change for biomass production for BECCS. In addition to technical challenges, one of the key constraints for the deployment of such climate technologies is social acceptance, where sections of the general public, or specific stakeholders, remain unconvinced with certain aspects of the technology due to ethical or political reasons.

Conclusion

As such, while CCS and BECCS may offer the ideal climate saviour solution to reduce overall carbon dioxide emissions, the technologies are still overcast with various technical and social challenges that limit their commercial usage for climate mitigation.

Biomass Energy and Sustainability

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Biomass energy 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. Biomass energy 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 in a sustainable manner.

Biomass resources can play a major role in reducing the reliance on fossil fuels by making use of thermo-chemical 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.

biomass-sustainability

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 sustainable development of rural as well as urban areas. Biomass energy could also aid in modernizing the agricultural economy and creating significant job opportunities.

Harvesting practices remove only a small portion of branches and tops leaving sufficient biomass to conserve organic matter and nutrients. Moreover, the ash obtained after combustion of biomass compensates for nutrient losses by fertilizing the soil periodically in natural forests as well as fields.

The impact of forest biomass utilization on the ecology and biodiversity has been found to be insignificant. Infact, forest residues are environmentally beneficial because of their potential to replace fossil fuels as an energy source.

A quick glance at popular biomass resources

A quick glance at popular biomass resources

Plantation of energy crops on abandoned agricultural land will lead to an increase in species diversity. The creation of structurally and species diverse forests helps in reducing the impacts of insects, diseases and weeds. Similarly the artificial creation of diversity is essential when genetically modified or genetically identical species are being planted.

Short-rotation crops give higher yields than forests so smaller tracts are needed to produce biomass which results in the reduction of area under intensive forest management. An intelligent approach in forest management will go a long way in the realization of sustainability goals.

Improvements in agricultural practices promises to increased biomass yields, reductions in cultivation costs, and improved environmental quality. Extensive research in the fields of plant genetics, analytical techniques, remote sensing and geographic information systems (GIS) will immensely help in increasing the energy potential of biomass feedstock.

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 biomass energy industry can also be achieved by laying more stress on green power marketing.

Recommended Reading: Exploring Synergy Between Bioenergy and Solar Power Systems

Role of Biomass Energy in Rural Development

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Biomass energy systems not only offer significant possibilities for clean energy production and agricultural waste management but also foster sustainable development in rural areas. The increased utilization of biomass energy will be instrumental in safeguarding the environment, generation of new job opportunities, sustainable development and health improvements in rural areas.

biomass-bales

Biomass energy has the potential to modernize the agricultural economy and catalyze rural development. The development of efficient biomass handling technology, improvement of agro-forestry systems and establishment of small, medium and large-scale biomass-based power plants can play a major role in rural development.

Sustainable harvesting practices remove only a small portion of branches and tops leaving sufficient biomass to conserve organic matter and nutrients. Moreover, the ash obtained after combustion of biomass compensates for nutrient losses by fertilizing the soil periodically in natural forests as well as fields.

Planting of energy crops on abandoned agricultural lands will lead to an increase in species diversity. The creation of structurally and species diverse forests helps in reducing the impacts of insects, diseases and weeds. Similarly the artificial creation of diversity is essential when genetically modified or genetically identical species are being planted.

Agricultural modernization promises to increased biomass yields, reductions in cultivation costs, and improved environmental quality. Extensive research in the fields of plant genetics, analytical techniques, remote sensing and geographic information systems (GIS) will immensely help in increasing the energy potential of biomass feedstock.

Rural areas are the preferred hunting ground for the development of biomass sector worldwide. By making use of various biological and thermal processes (anaerobic digestion, combustion, gasification, pyrolysis), agricultural wastes can be converted into biofuels, heat or electricity, and thus catalyzing sustainable development of rural areas economically, socially and environmentally.

Biomass energy can reduce 'fuel poverty' in remote and isolated communities

Biomass energy can reduce ‘fuel poverty’ in remote and isolated communities

A large amount of energy is utilized in the cultivation and processing of crops like sugarcane, wheat 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.

There are many areas in India where people still lack access to electricity and thus face enormous hardship in day-to-day lives. Biomass energy promises to reduce ‘fuel poverty’ commonly prevalent among remote and isolated communities.  Obviously, when a remote area is able to access reliable and cheap energy, it will lead to economic development and youth empowerment.

Biomass Energy in China

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Biomass energy in China has been developing at a rapid pace. The installed biomass power generation capacity in China increased sharply from 1.4 GW in 2006 to 14.88 GW in 2017. While the energy share of biomass remains relatively low compared to other sources of renewable energy, China plans to increase the proportion of biomass energy up to 15 percent and total installed capacity of biomass power generation to 30 GW by 2030.

biomass-china

In terms of impact, the theoretical biomass energy resource in China is about 5 billion tons coal equivalent, which equals 4 times of all energy consumption. As per conservative estimates, currently China is only using 5 percent of its total biomass potential.

According to IRENA, the majority of biomass capacity is in Eastern China, with the coastal province of Shandong accounting for 14 percent of the total alone. While the direct burning of mass for heat remains the primary use of biomass in China, in 2009, composition of China’s biomass power generation consisted in 62 percent of straw direct-fired power generation and 29 percent of waste incineration, with a mix of other feedstock accounting for the remaining 9 percent.

Biomass Resources in China

Major biomass resources in China include waste from agriculture, forestry, industries, animal manure and sewage, and municipal solid waste. While the largest contributing sources are estimated to be residues from annual crop production like wheat straw, much of the straw and stalk are presently used for cooking and heating in rural households at low efficiencies. Therefore, agricultural residues, forestry residues, and garden waste were found to be the most cited resources with big potential for energy production in China.

Agricultural residues are derived from agriculture harvesting such as maize, rice and cotton stalks, wheat straw and husks, and are most available in Central and northeastern China where most of the large stalk and straw potential is located. Because straw and stalks are produced as by-products of food production systems, they are perceived to be sustainable sources of biomass for energy that do not threaten food security.

Furthermore, it is estimated that China produces around 700 Mt of straw per year, 37 percent of which is corn straw, 28 percent rice, 20 percent wheat and 15 percent from various other crops. Around 50 percent of this straw is used for fertilizers, for which 350 Mt of straw is available for energy production per year.

Biomass resources are underutilized across China

Biomass resources are underutilized across China

Forestry residues are mostly available in the southern and central parts of China. While a few projects that use forestry wastes like tree bark and wood processing wastes are under way, one of the most cited resources with analyzed potential is garden waste. According to research, energy production from garden waste biomass accounted for 20.7 percent of China’s urban residential electricity consumption, or 12.6 percent of China’s transport gasoline demand in 2008.

Future Perspectives

The Chinese government believes that biomass feedstock should neither compete with edible food crops nor cause carbon debt or negative environmental impacts. As biomass takes on an increasing significant role in the China’s national energy-mix, future research specific to technology assessment, in addition to data collection and supply chain management of potential resources is necessary to continue to understand how biomass can become a game-changer in China’s energy future.

References

IRENA, 2014. Renewable Energy Prospects: China, REmap 2030 analysis. IRENA, Abu Dhabi. www.irena.org/remap

National Academy of Engineering and NRC, 2007: Energy Futures and Urban Air Pollution: Challenges for China and the United States.

Xingang, Z., Zhongfu, T., Pingkuo, L, 2013. Development goal of 30 GW for China’s biomass power generation: Will it be achieved? Renewable and Sustainable Energy Reviews, Volume 25, September 2013, 310–317.

Xingang, Z., Jieyu, W., Xiaomeng, L., Tiantian, F., Pingkuo, L, 2012. Focus on situation and policies for biomass power generation in China. Renewable and Sustainable Energy Reviews, Volume 16, Issue 6, August 2012, 3722–3729.

Li, J., Jinming, B. MOA/DOE Project Expert Team, 1998. Assessment of Biomass Resource Availability in China. China Environmental Science Press, Beijing, China.

Klimowicz, G., 2014. “China’s big plans for biomass,” Eco-Business, Global Biomass Series, accessed on Apr 6, 2015.

Shi, Y., Ge, Y., Chang, J., Shao, H., and Tang, Y., 2013. Garden waste biomass for renewable and sustainable energy production in China: Potential, challenges and development. Renewable and Sustainable Energy Reviews 22 (2013) 432–437

Xu, J. and Yuan, Z, 2015. “An overview of the biomass energy policy in China,” BESustainable, May 21, 2015.

How Green is Biomass?

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As we strive to shrink our global carbon footprint, society must alter its energy sources. Solar panels and wind turbines are two familiar types of green power that contribute to protecting the planet. Investing in renewables can improve the environment and lower the cost of electricity.

As scientists look for efficient and sustainable solutions to non-renewable energy use, they turn back to basics. People used to rely on fire for fuel. Today, we can utilize these age-old practices to limit our reliance on environmentally polluting fuel sources.

The Importance of Renewable Energy

Nearly 80% of our current energy comes from coal, oil and gas. The use of fossil fuels in power production harms human health and the planet.

About 2.6 million Americans experience health issues from oil and gas exposure from fossil fuel transportation and processing facilities. Benzene and formaldehyde are two toxins associated with nonrenewable energy production that contribute to leukemia and blood disorders. The workers who mine oil and gas also risk exposure to airborne pollutants that cause lung cancer and breathing difficulties.

The production of fossil fuel energy affects the environment by emitting greenhouse gases into the atmosphere. The greenhouse effect is a natural process that the Earth uses to maintain life on its surface. It keeps the global temperature consistent to protect the ecosystem’s functionality.

Adding pollutants into the atmosphere changes its composition. These greenhouse gases absorb the sun’s energy, convert it into heat and release it back to space. Excess contaminants make it difficult to allow heat to escape. This increases the global temperature over time.

Renewable energy sources act as an alternative to greenhouse gas-emitting power. Various companies are working on producing a chemical-free solution known as biomass energy.

What is Biomass?

Biomass is a form of renewable energy derived from organic materials. Wood was the original source used by the first humans for survival. Now, we can rely on wood pellets, sawdust, black liquor and more to create commercial and residential fuel options.

biomass-sustainability

We can also utilize agricultural matter to produce biomass. Soybeans, corn, algae, sugar cane and other plants can create fuel to power our homes, electric cars and devices. Scientists are also using refuse for energy production. Municipal solid waste, like cotton, paper, yarn and food, can transform into biomass power. A less appealing way to produce this renewable energy derives from animal manure and human waste.

Companies take these materials and create energy through a direct combustion process. It forms a refined liquid or gas to burn for power. Because plants grow naturally and indefinitely on Earth, biomass is a renewable source.

Environmental Effect of Biomass

Although biomass production and use emit no direct carbon into the environment, it may be less sustainable than other renewable power sources. When burned, these fuels release toxins like nitrogen oxide, sulfur dioxide and particulate matter into the atmosphere.

Elephant-Grass

Biomass production also contributes to deforestation. Many companies use soybeans to create the renewable fuel, which affects forests in Argentina. The country produces 15% of the global soy source, using 16 million hectares of forest land for production.

As Argentina increases production to meet international demands, it must cut down trees and vegetation to make space for agricultural growth. The monoculture of soy also leads to soil depletion. To reverse these environmental impacts, farms use synthetic fertilizers and pesticides on their land.

Because biomass crops are water-intensive, they contribute to runoff pollution. When farmers water their plants, the synthetic fertilizers and pesticides drain into the ocean, contributing to oxygen depletion and dead zones. The significant amount of water used to produce these crops leads to resource exploitation. It takes nearly 4,000 gallons of water to grow a bushel of corn for biomass energy.

Is Biomass Worth the Destruction?

Biomass can effectively reduce the carbon footprint. The renewable energy source also limits the adverse health effects associated with conventional energy production. However, it emits air pollutants into the atmosphere, causing deforestation and water exploitation, which decreases its sustainability.

The answer is complicated. Every renewable energy source has its downfalls. When you use a bit of energy from each green resource, you can limit your environmental impact and still power the planet.

Summary of Biomass Combustion Technologies

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Direct combustion is the best established and most commonly used technology for converting biomass to heat. During combustion, biomass fuel is burnt in excess air to produce heat. The first stage of combustion involves the evolution of combustible vapours from the biomass, which burn as flames. The residual material, in the form of charcoal, is burnt in a forced air supply to give more heat. The hot combustion gases are sometimes used directly for product drying, but more usually they are passed through a heat exchanger to produce hot air, hot water or steam.

Combustion_Moving_Grate

The combustion efficiency depends primarily on good contact between the oxygen in the air and the biomass fuel. The main products of efficient biomass combustion are carbon dioxide and water vapor, however tars, smoke and alkaline ash particles are also emitted. Minimization of these emissions and accommodation of their possible effects are important concerns in the design of environmentally acceptable biomass combustion systems.

Biomass combustion systems, based on a range of furnace designs, can be very efficient at producing hot gases, hot air, hot water or steam, typically recovering 65-90% of the energy contained in the fuel. Lower efficiencies are generally associated with wetter fuels. To cope with a diversity of fuel characteristics and combustion requirements, a number of designs of combustion furnaces or combustors are routinely utilized around the world

Underfeed Stokers

Biomass is fed into the combustion zone from underneath a firing grate. These stoker designs are only suitable for small scale systems up to a nominal boiler capacity of 6 MWth and for biomass fuels with low ash content, such as wood chips and sawdust. High ash content fuels such as bark, straw and cereals need more efficient ash removal systems.

Sintered or molten ash particles covering the upper surface of the fuel bed can cause problems in underfeed stokers due to unstable combustion conditions when the fuel and the air are breaking through the ash covered surface.

Grate Stokers

The most common type of biomass boiler is based on a grate to support a bed of fuel and to mix a controlled amount of combustion air, which often enters from beneath the grate. Biomass fuel is added at one end of the grate and is burned in a fuel bed which moves progressively down the grate, either via gravity or with mechanical assistance, to an ash removal system at the other end. In more sophisticated designs this allows the overall combustion process to be separated into its three main activities:

  • Initial fuel drying
  • Ignition and combustion of volatile constituents
  • Burning out of the char.

Grate stokers are well proven and reliable and can tolerate wide variations in fuel quality (i.e. variations in moisture content and particle size) as well as fuels with high ash content. They are also controllable and efficient.

Fluidized Bed Boilers

The basis for a fluidized bed combustion system is a bed of an inert mineral such as sand or limestone through which air is blown from below. The air is pumped through the bed in sufficient volume and at a high enough pressure to entrain the small particles of the bed material so that they behave much like a fluid.

The combustion chamber of a fluidized bed power plant is shaped so that above a certain height the air velocity drops below that necessary to entrain the particles. This helps retain the bulk of the entrained bed material towards the bottom of the chamber. Once the bed becomes hot, combustible material introduced into it will burn, generating heat as in a more conventional furnace. The proportion of combustible material such as biomass within the bed is normally only around 5%. The primary driving force for development of fluidized bed combustion is reduced SO2 and NOx emissions from coal combustion.

Bubbling fluidized bed (BFB) combustors are of interest for plants with a nominal boiler capacity greater than 10 MWth. Circulating fluidized bed (CFB) combustors are more suitable for plants larger than 30 MWth. The minimum plant size below which CFB and BFB technologies are not economically competitive is considered to be around 5-10 MWe.