Tag Archives: Biochar

Utilization of Date Palm Biomass

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Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits.

date-wastes

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

Date palm is considered a renewable natural resource because it can be replaced in a relatively short period of time. It takes 4 to 8 years for date palms to bear fruit after planting, and 7 to 10 years to produce viable yields for commercial harvest. Usually date palm wastes are burned in farms or disposed in landfills which cause environmental pollution in dates-producing nations.

The major constituents of date palm biomass are cellulose, hemicelluloses and lignin. In addition, date palm has high volatile solids content and low moisture content. These factors make date palm residues an excellent biomass resource in date-palm producing nations.

Date palm biomass is an excellent resource for charcoal production in Middle East

A wide range of physico-chemical, thermal and biochemical technologies exists for sustainable utilization of date palm biomass. Apart from charcoal production and energy conversion (using technologies like combustion and gasification), below are few ways for utilization of date palm wastes:

Conversion into fuel pellets or briquettes

Biomass pellets are a popular type of alternative fuel (analogous to coal), generally made from wood wastes and agricultural biomass. The biomass pelletization process consists of multiple steps including pre-treatment, pelletization and post-treatment of biomass wastes. Biomass pellets can be used as a coal replacement in power plant, industries and other application.

Conversion into energy-rich products

Biomass pyrolysis is the thermal decomposition of date palm biomass occurring in the absence of oxygen. The products of biomass pyrolysis include biochar, bio-oil and gases including methane, hydrogen, carbon monoxide, and carbon dioxide.

Depending on the thermal environment and the final temperature, pyrolysis will yield mainly biochar at low temperatures, less than 450 0C, when the heating rate is quite slow, and mainly gases at high temperatures, greater than 800 0C, with rapid heating rates. At an intermediate temperature and under relatively high heating rates, the main product is bio-oil.

Bio-oil can be upgraded to either a special engine fuel or through gasification processes to a syngas which can then be processed into biofuels. Bio-oil is particularly attractive for co-firing because it can be more readily handled and burned than solid fuel and is cheaper to transport and store.

Conversion into biofertilizer

Composting is the most popular method for biological decomposition of organic wastes. Date palm waste has around 80% organic content which makes it very well-suited for the composting process. Commercial-scale composting of date palm wastes can be carried out by using the traditional windrow method or a more advanced method like vermicomposting.

Biomass Pyrolysis Process

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Pyrolysis is the thermal decomposition of biomass occurring in the absence of oxygen. It is the fundamental chemical reaction that is the precursor of both the combustion and gasification processes and occurs naturally in the first two seconds. The products of biomass pyrolysis include biochar, bio-oil and gases including methane, hydrogen, carbon monoxide, and carbon dioxide.

Depending on the thermal environment and the final temperature, pyrolysis will yield mainly biochar at low temperatures, less than 450 0C, when the heating rate is quite slow, and mainly gases at high temperatures, greater than 800 0C, with rapid heating rates. At an intermediate temperature and under relatively high heating rates, the main product is bio-oil.

Pyrolysis can be performed at relatively small scale and at remote locations which enhance energy density of the biomass resource and reduce transport and handling costs.  Pyrolysis offers a flexible and attractive way of converting solid biomass into an easily stored and transported liquid, which can be successfully used for the production of heat, power and chemicals.

A wide range of biomass feedstocks can be used in pyrolysis processes. The pyrolysis process is very dependent on the moisture content of the feedstock, which should be around 10%. At higher moisture contents, high levels of water are produced and at lower levels there is a risk that the process only produces dust instead of oil. High-moisture waste streams, such as sludge and meat processing wastes, require drying before subjecting to pyrolysis.

The efficiency and nature of the pyrolysis process is dependent on the particle size of feedstocks. Most of the pyrolysis technologies can only process small particles to a maximum of 2 mm keeping in view the need for rapid heat transfer through the particle. The demand for small particle size means that the feedstock has to be size-reduced before being used for pyrolysis.

Pyrolysis processes can be categorized as slow pyrolysis or fast pyrolysis. Fast pyrolysis is currently the most widely used pyrolysis system. Slow pyrolysis takes several hours to complete and results in biochar as the main product. On the other hand, fast pyrolysis yields 60% bio-oil and takes seconds for complete pyrolysis. In addition, it gives 20% biochar and 20% syngas.

Bio-oil

Bio-oil is a dark brown liquid and has a similar composition to biomass. It has a much higher density than woody materials which reduces storage and transport costs. Bio-oil is not suitable for direct use in standard internal combustion engines. Alternatively, the oil can be upgraded to either a special engine fuel or through gasification processes to a syngas and then bio-diesel. Bio-oil is particularly attractive for co-firing because it can be more readily handled and burned than solid fuel and is cheaper to transport and store.

Bio-oil can offer major advantages over solid biomass and gasification due to the ease of handling, storage and combustion in an existing power station when special start-up procedures are not necessary. In addition, bio-oil is also a vital source for a wide range of organic compounds and speciality chemicals.

3 Ways Zero Valent Iron Can Help in Environment Protection

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Zero Valent Iron (ZVI) was developed to eliminate chlorinated hydrocarbon solvents in the soil. Industrial solvents are replete with chlorinated hydrocarbon, so much toxic and bad for the environment. They get disposed in the soil along with other toxic elements to cause harm to our surrounding. In the current years, significant improvements have taken place in the realm of iron-based technology.

Zero Valent Iron can be effectively used in soil remediation

The result of years of research and significant improvement in the iron-based technology is the advent of nanoscale or polymer-supported iron-containing nanoparticles to remove contaminants from solvents and soil. This is all due to the high surface area to the volume ratio of such nanoscale particles that favor the reaction kinetics and sorption.

But, know one thing that high pressure drops may restrict fixed-bed column application. This is why we now have modified nanosized ferrous particles to facilitate arsenic removal. The fabulous reducing agent helps in pollution recovery, and thus it benefits our environment.

Applications of Zero Valent Iron

ZVI in recent times is used widely for wastewater treatment, groundwater, and soil treatment. If made through the physico-chemical process in combination, the ZVI may be very small particles, having a large surface area. ZVI is beneficial for the environment, for it has a strong reductibility, great purity, long aging property, and similar features.

Zerovalent Iron can boost the chlorine removal efficiency of the soil, groundwater, and six valent chromium. Thus, it reduces the time required for environmental remediation. Acting as a fabulous reducing agent, it facilitates pollution recovery. Indeed, you may also combine it to bioremediation to further improve the efficacy of environment pollution recovery. Use it in the soil, solvents and industrial wastewater confidently to get rid of the contaminants. The use of ZVI paves the way for pure water and soil.

What you should look for in ZVI?

Are you planning to procure zero valent elemental metallic ions for wastewater treatment or soil remediation? Zerovalent metals or ZVI has a wide range of applications that range from electrodes and trenches to filters. Yes! It helps in the water filtration process, and thus we have pure drinking water. It gets rid of every trace of impurity or contaminant from the solvent or soil. It is important to look for a reliable company to procure ZVI.

Watch out for the following properties of ZVI

  • The particles must be fine enough to be customized as per your application
  • Look for the great adsorption performance and sound chemical activity
  • A large surface area for that very strong reductibility
  • Make sure the duration of its effect is very long to reduce the injections
  • Very fine ZVI particles to remediate pollution and to save remediation time and effort
  • Must be environment-friendly, deprived of any toxic compound

Enhanced nitrate-removing potential

Zero-valent metal has an enhanced nitrate removal capacity. It eliminates nitrate from the groundwater to facilitate remediation. Hence, biochar-supported ZVI can facilitate nitrate removal while the ones with wider pH can remove larger nitrates. Biochar composite eliminates nitrate from the groundwater without leaving any harmful by-products. But, biochar has a variable nitrate-removal capacity.

ZVI biochar has a potential to reduce nitrate by mediating the redox potential, the electron transfer, pH and thus facilitates enhanced removal or reduction of nitrate from the solvent or soil. Everything revolves around the logic of intensifying chemical reduction in order to eliminate nitrate from the soil or groundwater.

Nitrate and How it Accumulates

Nitrate is the form of nitrogen, which lies beneath the cultivable land. Nitrate is water soluble and may move through the soil quite easily. Owing to its high mobility, it moves to the groundwater table. Once it has moved to the groundwater table, it persists there and deposits to a very high level.

Thus, shallow groundwater is also at a risk of contamination from chemicals of land surfaces. This is a matter of concern, and indeed, nitrate in water may harm human health, aquatic life, livestock life and contaminate the surface water. We can say that it is not that harmful to adult humans, but it can significantly affect the health of the infants. It may reduce the level of oxygen in the blood to cause ‘blue baby’ disorder.

Hence, biological denitrification, ion exchange, and reverse osmosis are the treatment processes to handle this issue. The use of ZVI is a way to denitrification and the key to attaining a safe nitrate level in the water. A zero-valent metallic reduction is an effective way to refine dirty and polluted water. As soon as ZVI is placed in the flowing water or is added to the flowing water, there starts the process of oxidizing. The resultant chain reaction will purify water or remove the contaminants.

A Tool to Remediate Acid Mine Drainage

AMD or Acid Mine Drainage is the most common source of metal in places like the Appalachians, Tennessee, and Kentucky. It is important to remediate acid mine drainage for it is highly acidic and toxic. It is the major contributor to the arsenic environment and something needs to be done. AMD is a rich source of heavy and corrosive metals, acidic in nature. Biological treatment of Acid Mine Drainage is cost-effective, efficient and environment-friendly.

Biotechnological processes are an asset when it comes to treating Acid Mine Drainage in an effective manner. ZVI is environmentally sustainable. When it is very complicated and difficult to treat or remediate Acid Mine Drainage, ZVI eases the process. It gets rid of harmful elements or potentially hazardous substances from AMD to separate metal from acid and toxic compounds. There isn’t a need to abandon a mine site just because there are acidic metal deposits. Mine metals can be reclaimed with ZVI, and herein lays the environmental benefit.

Recycling of metallurgical waste

It is important to treat AMD or Acid Mine Drainage. The ecological solution to separate toxic metals, to reclaim water in large quantities is gaining a lot of attention. ZVI and zero valent metals save our natural resources and prepare the toxic metals for the recycling process. This is only possible through the separation of the acidic part.

We can recycle gallons of water that lay in the pond and other water bodies. It drops the acid level in the water and metal while also prevents heavy metallic reactions. When Acid Mine Drainage is one of the serious concerns in the realm of coal mining, zero valent metals prevent any exposure of sulfur-rich mineral to the water and atmospheric oxygen.

Final Thoughts

Zero-valent metals can help in the treatment of contaminated zones through the process of remediation. Zero valent iron is the highly reactive powder for remediation of wastewater and soil and works fabulously on environmentally contaminated areas. This remediation solution is highly efficient and benefits our environment in multiple ways.