Wood | BioEnergy Consult

A Glance at Woody Biomass Resources

By Salman Zafar | February 6, 2019 - 2:44 pm |February 6, 2019 Biomass Energy, Cogeneration

Pulp and Paper Industry Residues

The largest source of energy from wood is the waste product from the pulp and paper industry called black liquor. Logging and processing operations generate vast amounts of biomass residues. Wood processing produces sawdust and a collection of bark, branches and leaves/needles. A paper mill, which consumes vast amount of electricity, utilizes the pulp residues to create energy for in-house usage.

Forest Residues

Forest harvesting is a major source of biomass for energy. Harvesting may occur as thinning in young stands, or cutting in older stands for timber or pulp that also yields tops and branches usable for bioenergy. Harvesting operations usually remove only 25 to 50 percent of the volume, leaving the residues available as biomass for energy. Stands damaged by insects, disease or fire are additional sources of biomass. Forest residues normally have low density and fuel values that keep transport costs high, and so it is economical to reduce the biomass density in the forest itself.

Agricultural or Crop Residues

Crop residues encompasses all agricultural wastes such as straw, stem, stalk, leaves, husk, shell, peel, pulp, stubble, etc. which come from cereals (rice, wheat, maize or corn, sorghum, barley, millet), cotton, groundnut, jute, legumes (tomato, bean, soy) coffee, cacao, tea, fruits (banana, mango, coco, cashew) and palm oil.

Rice produces both straw and rice husks at the processing plant which can be conveniently and easily converted into energy. Significant quantities of biomass remain in the fields in the form of cob when maize is harvested which can be converted into energy. Sugar cane harvesting leads to harvest residues in the fields while processing produces fibrous bagasse, both of which are good sources of energy.

Energy Crops

Dedicated energy crops are another source of woody biomass for energy. These crops are fast-growing plants, trees or other herbaceous biomass which are harvested specifically for energy production. Rapidly-growing, pest-tolerant, site and soil-specific crops have been identified by making use of bioengineering. For example, operational yield in the northern hemisphere is 10-15 tonnes/ha annually. A typical 20 MW steam cycle power station using energy crops would require a land area of around 8,000 ha to supply energy on rotation.

Herbaceous energy crops are harvested annually after taking two to three years to reach full productivity. These include grasses such as switchgrass, elephant grass, bamboo, sweet sorghum, wheatgrass etc. Short rotation woody crops are fast growing hardwood trees harvested within five to eight years after planting. These include poplar, willow, silver maple, cottonwood, green ash, black walnut, sweetgum, and sycamore.

Industrial crops are grown to produce specific industrial chemicals or materials, e.g. kenaf and straws for fiber, and castor for ricinoleic acid. Agricultural crops include cornstarch and corn oil soybean oil and meal wheat starch, other vegetable oils etc. Aquatic resources such as algae, giant kelp, seaweed, and microflora also contribute to bioenergy feedstock.

Urban Wood Wastes

Such waste consists of lawn and tree trimmings, whole tree trunks, wood pallets and any other construction and demolition wastes made from lumber. The rejected woody material can be collected after a construction or demolition project and turned into mulch, compost or used to fuel bioenergy plants.

Biomass from Wood Processing Industries

By Salman Zafar | January 19, 2019 - 12:40 pm |January 19, 2019 Biomass Energy, Waste-to-energy

2 Comments

Wood processing industries primarily include sawmilling, plywood, wood panel, furniture, building component, flooring, particle board, moulding, jointing and craft industries. Biomass from wood processing industries is generally concentrated at the processing factories, e.g. plywood mills and sawmills. The amount of waste generated from wood processing industries varies from one type industry to another depending on the form of raw material and finished product.

Biomass from Wood Processing

The waste resulted from a wood processing is influenced by the diameter of logs being processed, type of saw, specification of product required and skill of workers. Generally, the waste from wood industries such as saw millings and plywood, veneer and others are sawdust, off-cuts, trims and shavings.

Sawdust arise from cutting, sizing, re-sawing, edging, while trims and shaving are the consequence of trimming and smoothing of wood. In general, processing of 1,000 kilos of wood in the furniture industries will lead to wood waste generation of almost half (45 %), i.e. 450 kilos of wood. Similarly, when processing 1,000 kilos of wood in sawmill, the waste will amount to more than half (52 %), i.e. 520 kilo of wood.

The biomass wastes generated from wood processing industries include sawdust, off-cuts and bark. Recycling of wood wastes is not done by all wood industries, particularly small to medium scale wood industries. The off-cuts and cutting are sold or being used as fuel for wood drying process. Bark and sawdust are usually burned.

Recycling of Wood Wastes

The use of wood wastes is usually practised in large and modern establishment; however, it is commonly only used to generate steam for process drying. The mechanical energy demand such as for cutting, sawing, shaving and pressing is mostly provided by diesel generating set and/or electricity grid. The electricity demand for such an industry is substantially high.

Recycling of wood wastes is not done by all wood industries, particularly by smallholders. These wastes are normally used as fuel for brick making and partly also for cooking. At medium or large establishments some of the wastes, like: dry sawdust and chips, are being used as fuel for wood drying process. Bark and waste sawdust are simply burned or dumped.

Importance of Heating Value

The heating or calorific value is a key factor when evaluating the applicability of a combustible material as a fuel. The heating value of wood and wood waste depends on the species, parts of the tree that are being used (core, bark, stem, wood, branch wood, etc.) and the moisture content of the wood. The upper limit of the heating or calorific value of 100% dry wood on a weight basis is relatively constant, around 20 MJ/kg.

In practice, the moisture content of wood during logging is about 50%. Depending on transportation and storing methods and conditions it may rise to 65% or fall to some 30% at the mill site. The moisture content of the wood waste in an industry depends on the stage where the waste is extracted and whether wood has been dried before this stage.

How to Choose Weather-Resistant Siding for your Home

By Salman Zafar | August 14, 2018 - 2:54 pm |August 14, 2018 Environment, Green

Vinyl siding

Vinyl siding is going to be one of the least-expensive materials you can put on the exterior of your home. That makes it one of the most common types of materials used. The advantages to vinyl siding aren’t just the price. It is impervious to water and many insects. The biggest disadvantage is that it can melt, burn or crack. In high winds, it can also make rattling noises. Also, if you are going for an upscale look, vinyl doesn’t have the same aesthetic appeal that other siding materials can deliver, and it typically isn’t used on higher-priced homes.

Plastic siding

Plastic siding is a relatively new alternative. The advantage of plastic siding is that it can resemble more expensive roofing material and requires very little upkeep. It is much thicker than its vinyl alternative, but that makes it more expensive. Although it’s costlier, if you are looking for a good weather-resistant siding, it is a grade above vinyl and may save you money in the long term as it is less prone to damage or necessary repairs.

Fiber cement siding

Fiber cement siding is also a new material on the market. It is typically a blend of cellulose, sand and cement and gives a much more aesthetically appealing look to the house. It looks much more like real wood than both plastic and vinyl. Its advantages are that it is insect- and fire-resistant. However, if you live in a harsh climate, it is probably not going to be your best choice.

Plastic siding is one of best options for weather-resistant conditions

Water that can accumulate from the freeze-thaw cycle can damage the siding if you don’t maintain it correctly by painting it with water-resilient paint. You can buy it pre-painted, but it is much costlier and the colors that you must choose from can be somewhat limited. The pre-factory paints tend to last longer. Although higher-maintenance than plastic and vinyl siding, it still requires less maintenance than wood siding.

Wood siding

Wood shingles and clapboard are considered the most aesthetically pleasing materials for your siding. They are also going to be the costliest and require the most maintenance. They have a traditional charm that you can’t get from other materials. Clapboard is going to be less expensive than wood siding, but it is still pricier than other alternatives such as vinyl, plastic and cement board.

Wood shingles are not going to be the best weather-resistant materials for harsh conditions. It is not uncommon for them to succumb to insects, be less fire-resistant and to twist or warp when subjected to harsh climates. Overall, it requires the most maintenance too. Painting frequently is a must. Although being capable of being factory-primed and painted, it will take periodic maintenance to keep it looking good and safe from exterior conditions.

Conclusion

Of all the choices, available, plastic siding may be the best for weather-resistant conditions. Offering you a hardy material, it can stand up to a lot. It may not be as aesthetically appealing as the other options, but you don’t have to worry about maintaining it or having to replace it. Whether budget is an issue or not, plastic siding offers the best protection against the harsh conditions of nature.

Energy Access to Refugees

By Eaman Abdallah Aman | August 10, 2018 - 2:10 pm |August 10, 2018 Biogas, Environment, Renewable Energy

2 Comments

There is a strong link between the serious humanitarian situation of refugees and lack of access to sustainable energy resources. According to a 2015 UNCHR report, there are more than 65.3 million displaced people around the world, the highest level of human displacement ever documented. Access to clean and affordable energy is a prerequisite for sustainable development of mankind, and refugees are no exception. Needless to say, almost all refugee camps are plagued by fuel poverty and urgent measure are required to make camps livable.

Usually the tragedy of displaced people doesn’t end at the refugee camp, rather it is a continuous exercise where securing clean, affordable and sustainable energy is a major concern. Although humanitarian agencies are providing food like grains, rice and wheat; yet food must be cooked before serving. Severe lack of modern cook stoves and access to clean fuel is a daily struggle for displaced people around the world. This article will shed some light on the current situation of energy access challenges being faced by displaced people in refugee camps.

Why Energy Access Matters?

Energy is the lifeline of our modern society and an enabler for economic development and advancement. Without safe and reliable access to energy, it is really difficult to meet basic human needs. Energy access is a challenge that touches every aspect of the lives of refugees and negatively impacts health, limits educational and economic opportunities, degrades the environment and promotes gender discrimination issues. Lack of energy access in refugee camps areas leads to energy poverty and worsen humanitarian conditions for vulnerable communities and groups.

Energy Access for Cooking

Refugee camps receive food aid from humanitarian agencies yet this food needs to be cooked before consumption. Thus, displaced people especially women and children take the responsibility of collecting firewood, biomass from areas around the camp. However, this expose women and minors to threats like sexual harassments, danger, death and children miss their opportunity for education. Moreover, depleting woods resources cause environmental degradation and spread deforestation which contributes to climate change. Moreover, cooking with wood affects the health of displaced people.

Access to efficient and modern cook stove is a primary solution to prevent health risks, save time and money, reduce human labour and combat climate change. However, humanitarian agencies and host countries can aid camp refugees in providing clean fuel for cooking because displaced people usually live below poverty level and often host countries can’t afford connecting the camp to the main grid. So, the issue of energy access is a challenge that requires immediate and practical solutions. A transition to sustainable energy is an advantage that will help displaced people, host countries and the environment.

Energy Access for Lighting

Lighting is considered as a major concern among refugees in their temporary homes or camps. In the camps life almost stops completely after sunset which delays activities, work and studying only during day time hours. Talking about two vulnerable groups in the refugees’ camps “women and children” for example, children’s right of education is reduced as they have fewer time to study and do homework. For women and girls, not having light means that they are subject to sexual violence and kidnapped especially when they go to public restrooms or collect fire woods away from their accommodations.

Rationale For Sustainable Solutions

Temporary solutions won’t yield results for displaced people as their reallocation, often described as “temporary”, often exceeds 20 years. Sustainable energy access for refugees is the answer to alleviate their dire humanitarian situation. It will have huge positive impacts on displaced people’s lives and well-being, preserve the environment and support host communities in saving fuel costs. Also, humanitarian agencies should work away a way from business as usual approach in providing aid, to be more innovative and work for practical sustainable solutions when tackling energy access challenge for refugee camps.

UN SDG 7 – Energy Access

The new UN SDG7 aims to “ensure access to affordable, reliable, sustainable and modern energy for all”. SDG 7 is a powerful tool to ensure that displaced people are not left behind when it comes to energy access rights. SDG7 implies on four dimensions: affordability, reliability, sustainability and modernity. They support and complete the aim of SDG7 to bring energy and lightening to empower all human around the world. All the four dimensions of the SDG7 are the day to day challenges facing displaced people. The lack of modern fuels and heavy reliance on primitive sources, such as wood and animal dung leads to indoor air pollution.

Energy access touches every aspect of life in refugee camps

For millions of people worldwide, life in refugee camps is a stark reality. Affordability is of concern for displaced people as most people flee their home countries with minimum possessions and belongings so they rely on host countries and international humanitarian agencies on providing subsidized fuel for cooking and lightening. In some places, host countries are itself on a natural resources stress to provide electricity for people and refugees are left behind with no energy access resources. However, affordability is of no use if the energy provision is not reliable (means energy supply is intermittent).

Parting Shot

Displaced people need a steady supply of energy for their sustenance and economic development. As for the sustainability provision, energy should produce a consistent stream of power to satisfy basic needs of the displaced people. The sustained power stream should be greater than the resulted waste and pollution which means that upgrading the primitive fuel sources used inside the camp area to the one of modern energy sources like solar energy, wind power, biogas and other off-grid technologies.

For more insights please read this article Renewable Energy in Refugee Camps

Biomass Energy in China

By Miriam Fernandez | August 1, 2018 - 12:46 pm |August 4, 2018 Agriculture, Biomass Energy, Renewable Energy, Supply Chain Management, Technology

1 Comment

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.

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

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.

Management of Construction Wastes

By Sunanda Swain | July 15, 2018 - 9:39 am |July 15, 2018 Environment, Recycling, Waste Management

3 Comments

A wide variety of wastes are generated during construction projects which may be classified into four categories – excavated wastes, demolition wastes, construction wastes and mixed wastes. Construction wastes are also known Construction and Demolition (C&D) wastes. Excavated materials is made up of soil, sand, gravel, rock, asphalt, etc. while demolition wastes is comprised by concrete, metal, roofing sheets, asbestos, brick, briquette, stone gypsum, wood material. Waste materials generated from construction activities are concrete, dry wall, plastics, ceramics tiles, metals, paper, cardboards, plastics, glass etc. In addition, mixed wastes, such as trash and organic wastes, are also produced in construction projects.

Almost 90 percent of construction wastes are inert or non-hazardous, and can be reused, reclaimed and recycled and reused. The non-recyclable, non-hazardous and hazardous waste materials constitute the remaining 10 percent. The non-inert materials include trees, green vegetation, trash and other organic materials while and the hazardous construction waste materials include contaminated soil, left over paints, solvent, aerosol cans, asbestos, paint thinners, striping paint, contaminated empty containers.

Sustainable management of construction wastes uses number of strategies and is based on the typical waste hierarchy: Avoid/ eliminate, reduce, reuse, recycle, treat and dispose.

Avoidance / Source Reduction

Avoidance or source reduction is considered as the best strategy for waste management and is the most economic way to reduce waste and minimise the environmental impacts of construction wastes. This can be done by avoiding use of hazardous materials such as asbestos-containing materials or chromated copper arsenate treated timber or through green purchasing of materials. This includes purchasing of non-toxic materials, pre-cut timbers and ordering materials of desired dimensions.

Reuse

Although source reduction and elimination are preferred options in the waste management hierarchy, it is always not possible to do so. In this case consider reuse, donation and salvage options to companies or people who need those. Reuse option lengthens the life of a material. Reuse strategy can be used in two ways.

Building Reuse – It includes reusing materials from existing buildings and maintaining certain percentages of building structural and non-structural elements such as interior walls, doors floor covering and ceilings.

Material Reuse – This is one of the most effective strategies for minimising environmental impacts which can be done by salvaging, refurbishing and reusing materials within the same building or in another building. Many of the exterior and interior materials can be recovered from existing buildings and reused in new ones. Such materials will include steel, walls, floor coverings, concrete, beams and posts, door frames, cabinetry and furniture, brick, and decorative items. Reuse of materials and products will help to reduce the demand for virgin materials and reduce wastes.

Recycle

There is very good potential to recycle many elements of construction waste. Recycling involves collecting, reprocessing and/ or recovering certain waste materials to make new materials or products. Often roll-off containers are used to transport the waste. Rubble can be crushed and reused in construction projects. Waste wood can also be recovered and recycled. Many construction waste materials that are still usable can be donated to non-profit organizations. This keeps the material out of the landfill and supports a good cause.

Treat and Dispose

This option should be considered after all other options are exhausted. The disposal of construction materials should be carried out in appropriate manner through an approved contractor. For examples, certain components of construction waste such as plasterboard are hazardous once landfilled. Plasterboard is broken down in landfill conditions releasing hydrogen sulfide, a toxic gas.