Blog List

Tuesday 1 March 2016

Enzymes in Pineapple Juice

Pineapples are a tropical fruit that are grown primarily in Costa Rica, Honduras, Mexico, Dominican Republic, El Salvador, Ecuador and Nicaragua and imported into the United States. Pineapples are a rich source of vitamin C and contain the enzyme bromelain, which aids the digestive system. Bromelain is found in the pineapple stem and in pineapple juice.

Enzymes in Pineapple Juice
Pineapple juice contains the enzyme bromelain Photo Credit anna1311/iStock/Getty Images

Bromelain

Bromelain is used for a variety of medicinal purposes. Bromelain seems to have anti-inflammatory properties, notes MedlinePlus. It is used to treat inflammation in the nose and sinuses, ulcerative colitis, relaxing muscles and helping the body reduce body fat. Bromelain appears to cause the production of substances that fight pain and swelling; it also
also contains chemicals that interfere with the growth of tumor cells and slow blood clotting.

Anti-Inflammatory Properties of Pineapple Juice

Numerous studies have looked at the benefits of pineapple juice and the enzyme bromelain when it comes to the treatment of inflammation. A study published in December 2010 in the journal “Inflammatory Bowel Diseases” looked at the connection between pineapple juice supplementation and the treatment of chronic colitis. Previous studies had shown that purified bromelain from the pineapple stem had decreased the severity of colonic inflammation and researchers wanted to see if the bromelain concentrations in the juice were capable of the same. Their results showed that long-term dietary supplementation of fresh pineapple juice with active bromelain enzymes was safe and did reduce inflammation severity.

Bromelain and Pityriasis Lichenoides Chronica

Pityriasis lichenoides chronica is a chronic skin condition of unknown origin that causes small scaling papules on the skin. It most often affects children and young adults. It is hard to treat and does not always respond to treatment. A study published in 2007 in the “Journal of Dermatological Treatment” looked at the possible effects of bromelain extracts from pineapple and the treatment of PLC. Researchers concluded that the efficacy of bromelain in treating PLC could be related to its anti-inflammatory, immunomodulatory and/or anti-viral properties.

Considerations

While pineapple juice does provide a high source of vitamin C and the enzyme bromelain, there are considerations that you need to consider before adding regular pineapple juice to your diet. Because bromelain is a natural blood thinner, you should not add pineapple juice to your diet if you take medication like Coumadin for blood thinning, as it can greatly increase your risk of bleeding and bruising. Before adding pineapple juice to your regular diet, consult with your physician. He may advise against it or adjust your medication levels to account for the bromelain.
www.livestrong.com

Pineapple to Reduce Stomach Fat

Pineapple can flatten your tummy, prevent stomach distention and help your body burn a few extra calories. Pineapple is a nutrient-rich fruit containing vitamin C, manganese, thiamine, copper, fiber and vitamin B-6. Additionally, pineapple contains one very important enzyme: bromelain, which is found in the stem and within the juice of a pineapple. This enzyme metabolizes protein, contributing to a number of health benefits, including a flatter abdomen.


Pineapple to Reduce Stomach Fat


A woman cuts up a pineapple on a cutting board. Photo Credit Alliance/iStock/Getty Images

Stomach Bloating

Bromelain digests proteins, which aids in relieving heartburn or an upset stomach. According to the University of Maryland, one animal study revealed that bromelain’s antibacterial properties help combat the bacteria causing diarrhea. Preliminary research shows bromelain to be effective in healing bowel disorders. Relief from stomach conditions can produce a less-bloated abdomen and a slender waist.

Inflammation

Pineapple contains a combination of digestive enzymes that decreases inflammation and edema, as reported by the University of California at San Diego. Pain and inflammation caused by trauma, including surgery, arthritis or sports injury, is reduced when bromelain is consumed. This important enzyme aids in healing and regenerating the digestive lining of the stomach. Belly fat can be mistaken for water retention and stomach distention from inflammation of the bowels. Pineapple helps ease this inflammation resulting in a flatter, slimmer look.

Fat Burning

According to Clayton College of Natural Health, freshly juiced pineapple may help burn fat. Bromelain can work in conjunction with other enzymes, such as lipase, an enzyme that helps digest fats. According to Purdue University, bromelain is thought to aid in appetite inhibition and enhance fat excretion. Additionally, pineapple is a catabolic food, meaning that your body expends more calories digesting the fruit than the number of calories the fruit contains. This results in an overall calorie deficit.

Warnings

Overall, pineapple is a very safe food. However, juice from unripe pineapples may cause vomiting. Allergic reactions may occur among those who have allergies to honeybee venom or olive tree pollen. Bromelain may overstimulate anticoagulant drugs. Talk to your physician about bromelain consumption if you are taking a blood thinner. Consuming more than two to three servings of pineapple per day among pregnant women has not been researched thoroughly to conclude whether bromelain is safe for expectant or breast-feeding mothers.
www.livestrong.com

Are There Side Effects of Eating a Banana a Day?

If you enjoy bananas, there's probably no reason to not to eat one of these soft, sweet fruits every day. Bananas are rich in potassium, fiber and vitamin C, and they contain far fewer calories than potato chips or cookies. That said, bananas may cause side effects in some people. If these symptoms are severe, you may need to quit your banana habit.

Are There Side Effects of Eating a Banana a Day?
A sliced banana on a cutting board. Photo Credit tycoon751/iStock/Getty Images

Potential Risks

Bananas may cause gas and bloating in certain people. In addition, they may worsen symptoms of irritable bowel syndrome -- a chronic condition that causes diarrhea, bloating and cramping -- according to Harvard Health Publications. And although bananas are relatively light -- each medium fruit contains just 105 calories -- adding them to your existing weight-maintenance diet without omitting a food of similar calories may cause weight gain, as your body stores excess calories as body fat.
www.livestrong.com

PULP MILL

pulp mill is a manufacturing facility that converts wood chips or other plant fibre source into a thick fibre board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical or fully chemical methods (kraft and sulfite processes). The finished product may be either bleached or non-bleached, depending on the customer requirements.
Wood and other plant materials used to make pulp contain three main components (apart from water): cellulose fibres (desired for paper making), lignin (a three-dimensional polymer that binds the cellulose fibres together) and hemicelluloses (shorter branched carbohydrate polymers). The aim of pulping is to break down the bulk structure of the fibre source, be it chips, stems or other plant parts, into the constituent fibres.
Chemical pulping achieves this by degrading the lignin and hemicellulose into small, water-soluble molecules which can be washed away from the cellulose fibres without depolymerizing the cellulose fibres (chemically depolymerizing the cellulose weakens the fibres). The various mechanical pulping methods, such as groundwood (GW) and refiner mechanical (RMP) pulping, physically tear the cellulose fibres one from another. Much of the lignin remains adhering to the fibres. Strength is impaired because the fibres may be cut. Related hybrid pulping methods use a combination of chemical and thermal treatment to begin an abbreviated chemical pulping process, followed immediately by a mechanical treatment to separate the fibres. These hybrid methods include thermomechanical pulping (TMP) and chemithermomechanical pulping (CTMP). The chemical and thermal treatments reduce the amount of energy subsequently required by the mechanical treatment, and also reduce the amount of strength loss suffered by the fibres
The Mill

Much of the information about the technology in following subsections is from the book by C.J. Biermann. The chemistry of the various pulping processes can be found in Sjöström's book.


International Paper Company, pulp mill

Preparation of Fibre Source
The most common fibre source for pulp mills is pulpwood. Other common sources are bagasse and fibre crops. The first step in all mills using wood (trees) as the fibre source is to remove the bark. Bark contains relatively few usable fibres and darkens the pulp. The removed bark is burned, along with other unusable plant material, to generate steam, to run the mill. Almost all wood is then chipped before being processed further in order to free the fibres.
Removal of the bark is done in a barker (or debarker). The bark adhesion is about 3–5 kg/cm2 in the growing season (summer) and 2-3 times higher in the dormant season (winter). The bark of frozen logs is even more difficult to remove.
In chemical pulp mills, the bark introduces unwanted contaminants such as calcium, silica and aluminium that cause scaling and give an extra loading for the chemical recovery system. Birch bark contains betulin, a terpenoid that easily creates deposits in a pulp mill.
Mechanical Pulp Mills

The earliest mills used sandstone grinding rollers to break up small wood logs called "bolts", but the use of natural stone ended in the 1940s with the introduction of manufactured stones with embedded silicon carbide or aluminum oxide. The pulp made by this process is known as "stone groundwood" pulp (SGW). If the wood is ground in a pressurized,sealed grinder the pulp is classified as "pressure groundwood" (PGW) pulp. Most modern mills use chips rather than logs and ridged metal discs called refiner plates instead of grindstones. If the chips are just ground up with the plates, the pulp is called "refiner mechanical" pulp (RMP), if the chips are steamed while being refined the pulp is called "thermomechanical" pulp (TMP). Steam treatment significantly reduces the total energy needed to make the pulp and decreases the damage (cutting) to fibers. Mechanical pulp mills use large amounts of energy, mostly electricity to power motors which turn the grinders. A rough estimate of the electrical energy needed is 10,000 megajoules (MJ) per tonne of pulp (2,750 kWh per tonne) 
Chemicals Pulp Mills
Chemical pulping processes such as the kraft (or sulphate) process and the sulfite process remove much of the hemicelluloses and lignin. The kraft process does less damage to the cellulose fibres than the sulfite process, thereby producing stronger fibres, but the sulfite process makes pulp that is easier to bleach. The chemical pulping processes use a combination of high temperature and alkaline (kraft) or acidic (sulfite) chemicals to break the chemical bonds of the lignin.
Pulp mill at Blankenstein (Germany)
The material fed into the digester must be small enough to allow the pulping liquor to penetrate the pieces completely. In the case of wood, the logs are chipped and the chips screened so that what is fed to the digester is a uniform size. The oversize chips are rechipped or used as fuel, sawdust is burned. The screened chips or cut plant material (bamboo, kenaf, etc.) goes to the digester where it is mixed an aqueous solution of the pulping chemicals, then heated with steam. In the kraft process the pulping chemicals are sodium hydroxide and sodium sulphide and the solution is known as white liquor. In the sulfite process the pulping chemical is a mixture of metal (sodium, magnesium, potassium or calcium) or ammonium sulphite or sulfite.
After several hours in the digester, the chips or cut plant material breaks down into a thick porridge-like consistency and is "blown" or squeezed from the outlet of the digester through an airlock. The sudden change in pressure results in a rapid expansion of the fibres, separating the fibres even more. The resulting fibre suspension in water solution is called "brown stock".
Brown stock washers, using countercurrent flow, remove the spent cooking chemicals and degraded lignin and hemicellulose. The extracted liquid, known as black liquor n the kraft process, and red or brown liquor in the sulfite processes, is concentrated, burned and the sodium and sulphur compounds recycled in the recovery process. Lignsulphonates are a useful byproduct recovered from the spent liquor in the sulfite process. The clean pulp (stock) can be bleached in the bleach plant or left unbleached, depending on the end use. The stock is sprayed onto the pulp machine wire, water drains off, more water is removed by pressing the sheet of fibres, and the sheet is then dried. At this point the sheets of pulp are several millimetres thick and have a coarse surface: it is not yet paper. The dried pulp is cut, stacked, bailed and shipped to another facility for whatever further process is needed.
Bleached kraft pulp and bleached sulfite pulp are used to make high quality, white printing paper. One of the most visible uses for unbleached kraft pulp is to make brown paper shopping bags and wrapping paper where strength is particularly important. A special grade of bleached sulfite pulp, known as dissolving pulp, is used to make cellulose derivatives such as methylcellulos which are used in a wide range of everyday products from laxatives to baked good to wallpaper paste.
Chemical-Mechanicals in Pulp Mills

Some mills pretreat wood chips or other plant material like straw with sodium carbonate, sodium hydroxide, sodium sulfite, and other chemical prior to refining with equipment similar to a mechanical mill. The conditions of the chemical treatment are much less vigorous (lower temperature, shorter time, less extreme pH) than in a chemical pulping process, since the goal is to make the fibers easier to refine, not to remove lignin as in a fully chemical process. Pulps made using these hybrid processes are known as chemi-thermomechanical pulps (CTMP). Sometimes a CTMP mill is located on the same site as a kraft mill so that the effluent from the CTMP mill can be treat

Scheduling in Pulp Mills

The pulp process involves many production stages, usually coupled with intermediate storage tanks. As each stage has a different reliability and bottlenecks may vary from day to day, scheduling a pulp mill needs to take into account these bottlenecks and the probability of a disturbance or breakdown.  Each stage also may have different decision variables, such as steam / water / chemical input, etc. Finally, scheduling needs to consider fuel optimisation and CO2 emissions, because part of the energy requirements may be met from fossil-fuel boilers. The overall aim is to maximise production at minimum cost.

References
  1. ^ Biermann, Christopher J. (1993). Essentials of Pulping and Papermaking. San Diego: Academic Press, Inc. ISBN 0-12-097360-X
  2. ^ Eero Sjöström (1993). Wood Chemistry: Fundamentals and Applications. San Diego: Academic Press. ISBN 0-12-647481-8
  3. ^ "Uses of lignosulphonates. Retrieved 2007-10-07.
  4. ^ Gunnarsson, H., Rönnqvist, M. (2008). Solving a multi-period supply chain problem for a pulp company using heuristics - an application to Södra Cell ab. International Journal of Production Economics 116 (1): 75-94
  5. ^ Klugman, S., Karlsson, M., Moshfegh, B. (2009). A Swedish integrated pulp and paper mill energy optimisation and local heat cooperation. Energy Policy 37 (7): 2514-2524

- Wikipedia 

PULP PAPER

Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fiber crops or waste paper. The wood fiber sources required for pulping are "45% sawmill residue, 21% logs and chips, and 34% recycled paper" (Canada, 2014). Pulp is one of the most abundant raw materials worldwide.


Structure of fibres of pulp

History
Using wood to make paper is a fairly recent innovation. The ancient Egyptians were the first to make paper by crushing reeds and pressing them together to form a paper-like material. Later, papermaking using cotton and linen fibers spread to Europe in the 13th century. Medieval historian Lynn White credited the spinning wheel with increasing the supply of rags, which led to cheap paper, which was a factor in the development of printing. By the 1800s, fibre crops such as flax, which provided linen fibres, were still the primary material source, and paper was a relatively expensive commodity. The use of wood to make pulp for paper began with the development of mechanical pulping in Germany by F.G. Keller in the 1840s, and by the Canadian inventor Charles Fenerty in Nova Scotia. Chemical processes quickly followed, first with J. Roth's use of sulfurous acid to treat wood, followed by Benjamin Tilghman's U.S. patent on the use of calcium bisulfite, Ca(HSO3)2, to pulp wood in 1867. Almost a decade later the first commercial sulfite pulp mill was built in Sweden. It used magnesium as the counter ion and was based on work by Carl Daniel Ekman. By 1900, sulfite pulping had become the dominant means of producing wood pulp, surpassing mechanical pulping methods. The competing chemical pulping process, the sulfate or kraft process was developed by Carl F. Dahl in 1879 and the first kraft mill started (in Sweden) in 1890. The invention of the recovery boiler by G.H. Tomlinson in the early 1930s allowed kraft mills to recycle almost all of their pulping chemicals. This, along with the ability of the kraft process to accept a wider variety of types of wood and produce stronger fibres made the kraft process the dominant pulping process starting in the 1940s. 
Pulp at a paper mill near Pensacola, 1947
Global production of wood pulp in 2006 was 175 million tons (160 million tonnes). In the previous year, 63 million tons (57 million tonnes) of market pulp (not made into paper in the same facility) was sold, with Canada being the largest source at 21 percent of the total, followed by the United States at 16 percent. Chemical pulp made up 93 percent of market pulp.
Manufacturer of Wood Pulp
The timber resources used to make wood pulp are referred to as pulpwood. Wood pulp comes from softwood trees such as spruce, pine, fir,, larch and hemlock and hardwoods such as eucalyptus, aspen and birch.
A pulp mill is a manufacturing facility that converts wood chips or other plant fibre source into a thick fiberboard which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical or fully chemical methods (kraft and sulfite processes). The finished product may be either bleached or non-bleached, depending on the customer requirements.
Fibres in wood pulp
Wood and other plant materials used to make pulp contain three main components (apart from water): cellulose fibers (desired for papermaking), lignin a three-dimensional polymer that binds the cellulose fibres together) and hemicelluloses(shorter branched carbohydrate polymers). The aim of pulping is to break down the bulk structure of the fibre source, be it chips, stems or , other plant parts, into the constituent fibres.
Chemical pulping achieves this by degrading the lignin and hemicellulose into small, water-soluble molecules which can be washed away from the cellulose fibres without depolymerizing the cellulose fibres (chemically depolymerizing the cellulose weakens the fibres). The various mechanical pulping methods, such as groundwood (GW) and refiner mechanical (RMP) pulping, physically tear the cellulose fibres one from another. Much of the lignin remains adhering to the fibres. Strength is impaired because the fibres may be cut. There are a number of related hybrid pulping methods that use a combination of chemical and thermal treatment to begin an abbreviated chemical pulping process, followed immediately by a mechanical treatment to separate the fibres. These hybrid methods include thermomechanical pulping, also known as TMP, and chemithermomechanical pulping, also known as CTMP. The chemical and thermal treatments reduce the amount of energy subsequently required by the mechanical treatment, and also reduce the amount of strength loss suffered by the fibres.
Global pulp production by category (2000)
Pulp categoryProduction [M]
Chemical131.2
-Kraft117.0
-Sulfite7.0
-Semichemical7.2
Mechanical37.8
Nonwood18.0
Total virgin fibres187.0
Recovered fibres147.0
Total pulp334.0
Harvesting Tree
Many kinds of paper are made from wood with nothing else mixed into them (with some exceptions, like resume paper, which may include cotton). This includes newspaper, magazines and even toilet paper. Most pulp mills use good forest management practices in harvesting trees to ensure that they have a sustainable source of raw materials. One of the major complaints about harvesting wood for pulp mills is that it reduces the biodiversity of the harvested forest. Trees raised specifically for pulp production account for 16 percent of world pulp production, old-growth forests account for 9 percent, and second- and third- and more generation forests account for the rest. Reforestation is practiced in most areas, so trees are a renewable resource. The FSC (Forest Stewardship Council), SFI (Sustainable Forestry Initiative), PEFC (Programme for the Endorsement of Forest Certification), and other bodies certify paper made from trees harvested according to guidelines meant to ensure good forestry practices.
The number of trees consumed depends on whether mechanical processes or chemical processes are used. It has been estimated that based on a mixture of softwoods and hardwoods 12 metres (40 ft) tall and 15-20 centimetres (6–8 in) in diameter, it would take an average of 24 trees to produce 0.9 tonne (1 ton) of printing and writing paper, using the kraft process (chemical pulping). Mechanical pulping is about twice as efficient in using trees, since almost all of the wood is used to make fibre, therefore it takes about 12 trees to make 0.9 tonne (1 ton) of mechanical pulp or newsprint.
There are roughly 2 short tons in a cord of wood.
Preparations for Pulping

Wood chipping is the act and industry of chipping wood for pulp, but also for other processed wood products and mulch. Only the heartwood and sapwood are useful for making pulp. Bark contains relatively few useful fibers and is removed and used as fuel to provide steam for use in the pulp mill. Most pulping processes require that the wood be chipped and screened to provide uniform sized chips.

Pulping
There are a number of different processes which can be used to separate the wood fiber:

Mechanical Pulp

Manufactured grindstones with embedded silicon carbide or aluminum oxide can be used to grind small wood logs called "bolts" to make stone pulp (SGW). If the wood is steamed prior to grinding it is known as pressure ground wood pulp (PGW). Most modern mills use chips rather than logs and ridged metal discs called refiner plates instead of grindstones. If the chips are just ground up with the plates, the pulp is called refiner mechanical pulp (RMP) and if the chips are steamed while being refined the pulp is called thermomechanical pulp (TMP). Steam treatment significantly reduces the total energy needed to make the pulp and decreases the damage (cutting) to fibres. Mechanical pulps are used for products that require less strength, such as newsprint and paperboards.

Themi-Thermomechanical Pulp

Wood chips can be pretreated with sodium carbonate, sodium hydroxide, sodium sulfite and other chemicals prior to refining with equipment similar to a mechanical mill. The conditions of the chemical treatment are much less vigorous (lower temperature, shorter time, less extreme pH, than in a chemical pulping process since the goal is to make the fibres easier to refine, not to remove lignin as in a fully chemical process. Pulps made using these hybrid processes are known as chemithermomechanical pulps (CTMP).

Chemical Pulp
Chemical pulp is produced by combining wood chips and chemicals in large vessels known as digesters where heat and the chemicals break down the lignin, which binds the cellulose fibres together, without seriously degrading the cellulose fibres. Chemical pulp is used for materials that need to be stronger or combined with mechanical pulps to give a product different characteristics. The kraft process is the dominant chemical pulping method, with the sulfite process being second. Historically soda pulping was the first successful chemical pulping method.

Recycled Pulp
Recycled pulp is also called deinked pulp (DIP). DIP is recycled paper which has been processed by chemicals, thus removing printing inks and other unwanted elements and freed the paper fibres. The process is called deinking.
DIP is used as raw material in paper making. Many newsprint, toilet paper and facial, tissue grades commonly contain 100 percent deinked pulp and in many other grades, such as lightweight coated for offset and printing and writing papers for office and home use, DIP makes up a substantial proportion of the furnish.
Organosolv Pulping
Organosolv pulping uses organic solvents at temperatures above 140 °C to break down lignin and hemicellulose into soluble fragments. The pulping liquor is easily recovered by distillation. The reason for using a solvent is to make the lignin more soluble in the cooking liquor. Most common used solvents are methanol, ethanol, formic acid and acetic acid often in combination with water.

Alternatively Pulping Methods
Research is under way to develop biopulping (biological pulping), similar to chemical pulping but using certain species of fungi that are able to break down the unwanted lignin, but not the cellulose fibres. In the bio pulping process, the fungal enzyme lignin peroxida se- selectively digests lignin to leave remaining cellulose fibres. This could have major environmental benefits in reducing the pollution associated with chemical pulping. The pulp is bleached using chlorine dioxide stage followed by neutralization and calcium hypochlorite. The oxidizing agent in either case oxidizes and destroys the dyes formed from the tannins of the wood and accentuated (reinforced) by sulfides present in it.
Steam exploded fibreis a pulping and extraction technique that has been applied to wood and other fibrous organic material.
Bleaching

The pulp produced up to this point in the process can be bleached to produce a white paper product. The chemicals used to bleach pulp have been a source of environmental concern, and recently the pulp industry has been using alternatives to chlorine such as chlorine dioxide, oxygen ozone and hydrogen peroxide

Alternative to Wood Pulp
However, wood is also a renewable resource, with about 90 percent of pulp coming from plantations or reforested areas. Non-wood fibre sources account for about 5–10 percent of global pulp production, for a variety of reasons, including seasonal availability, problems with chemical recovery, brightness of the pulp etc. Non-wood pulp processing requires a high use of water and energy. 
Nonwovens are in some applications alternatives to paper made from wood pulp, like filter paper or tea bags.
Comparison of typical feedstocks used in pulping
ComponentWoodNonwood
Carbohydrates65–80%50–80%
Cellulose
40–45%30–45%
Hemicellulose
23–35%20–35%
Lignin20–30%10–25%
Extractives2–5%5–15%
Proteins<0.5%5–10%
Inorganics0.1–1%0.5–10%
SiO2
<0.1%0.5–7%

Market Pulp

Market pulp is any variety of pulp that is produced in one location, dried and shipped to another location for further processing. Important quality parameters for pulp not directly related to the fibres are brightness, dirt levels, viscosity and ash content. In 2004 it accounted for about 55 million metric tons of market pulp.

Air Dry Pulp

Air dry pulp is the most common form to sell pulp. This is pulp dried to about 10 percent moisture content. It is normally delivered as sheeted bales of 250 kg. The reason to leave 10 percent moisture in the pulp is that this minimizes the fibre to fibre bonding and makes it easier to disperse the pulp in water for further processing to paper.

Roll Pulp

Roll pulp or reel pulp is the most common delivery form of pulp to non traditional pulp markets. Fluff pulp is normally shipped on rolls (reels). This pulp is dried to 5–6 percent moisture content. At the customer this is going to a comminution process to prepare for further processing.

Flash Dried Pulp

Some pulps are flash dried. This is done by pressing the pulp to about 50 percent moisture content and then let it fall through silos that are 15–17 m high. Gas fired hot air is the normal heat source. The temperature is well above the char point of cellulose, but large amount of moisture in the fibre wall and lumen prevents the fibres from being incinerated. It is often not dried down to 10 percent moisture (air dry). The bales are not as densely packed as air dry pulp.
Environmental Concern

The major environmental impacts of producing wood pulp come from its impact on forest sources and from its waste products.

Forest Resources

The impact of logging to provide the raw material for wood pulp is an area of intense debate. Modern logging practices, using forest management seek to provide a reliable, renewable source of raw materials for pulp mills. The practice of clear cutting is a particularly sensitive issue since it is a very visible effect of logging. Reforestation,  the planting of tree seedlings on logged areas, has also been criticized for decreasing biodiversity because reforested areas are monocultures. Logging of old growth forests accounts for less than 10 percent of wood pulp, but is one of the most controversial issues.

Effluents from Pulp Mills
The process effluents are treated in a biological effluent treatment plant, which guarantees that the effluents are not toxic in the recipient.
Mechanical pulp is not a major cause for environmental concern since most of the organic material is retained in the pulp, and the chemicals used (hydrogen peroxide and sodium dithionite) produce benign byproducts (water and sodium sulfate (finally), respectively).
Chemical pulp mills, especially kraft mills, are energy self-sufficient and very nearly closed cycle with respect to inorganic chemicals.
Bleaching with chlorine produces large amounts of organochlorine compounds, including dioxins.
Odor Problems

The kraft pulping reaction in particular releases foul-smelling compounds. The hydrogen sulfide reagent that degrades lignin structure also causes some demethylation to produce methanethiol,  dimethyl sulfide and dimethyl disulfide, These same compounds are released during many forms of microbial decay, including the internal microbial action in Camembert cheese, although the kraft process is a chemical one and does not involve any microbial degradation. These compounds have extremely low odor thresholds and disagreeable smells; a common saying in communities economically dependent on nearby papermills is "Smells like a job" or "Smells like money."

Applications
The main applications for pulp are paper and board, production. The furnish of pulps used depends on the quality on the finished paper. Important quality parameters are wood furnish, brightness, viscosity, extractives, dirt count and strength.
Chemical pulps are used for making nanocellulose.
Speciality pulp grades have many other applications. Dissolving pulp is used in making regenerated cellulose that is used textile and cellophane production. It is also used to make cellulose derivatives. Fluff pulp is used in diapers, feminine hygiene products and non-wovens.
Paper Production

The Fourdrinier Machine is the basis for most modern papermaking, and it has been used in some variation since its conception. It accomplishes all the steps needed to transform a source of wood pulp into a final paper product.

Economics

In 2009, NBSK pulp sold for $650/ton in the United States. The price had dropped due to falling demand when newspapers reduced their size, in part, as a result of the recession

References

  1.  Sixta, Herbert (2006). "Preface". Handbook of Pulp 1. Wiley-VCH Verlag & Co KGaA. p. XXIII. ISBN 3-527-30999-3.
  2. ^ Marchetti, Cesare (1879). "A Postmortem Technology Assessment of the Spinning Wheel: The Last 1000 Years, Technological Forecasting and Social Change, 13; pp. 91-93"(PDF).
  3. a b E. Sjöström (1993). Wood Chemistry: Fundamentals and Applications. Academic Press. 

- Wikipedia 

How to Make Baked Banana Chips


How to Make Baked Banana Chips
How to Make Baked Banana Chips Photo Credit Thomas Hooke/Demand Media
Versatile tropical fruits, bananas are nutritional powerhouses, rich in vitamin C, potassium and dietary fiber. Crispy, sweet and guilt-free, baked bananas chips are a cinch to make. A portable, high-energy treat, baked banana chips are just right for a hiking trip or as part of a healthy lunch. Eat the chips as is, or combine them with a variety of nuts and dried fruits for a healthy trail mix.

Bananas

How to Make Baked Banana Chips
Photo Credit Thomas Hooke/Demand Media
For the best flavor, choose bananas that are ripe but firm with a few brown speckles but no bruises, soft areas or large brown spots. Cut the bananas into thin slices. For extra crispy banana chips, make the slices about 1/8 inch. Otherwise, cut the bananas into 1/4-inch slices. Depending on the thickness of the slices, two large bananas make about 60 chips.

Lemon Juice


How to Make Baked Banana Chips
Photo Credit Thomas Hooke/Demand Media

Lemon juice adds flavor and vitamin C but, more importantly, prevents the banana chips from turning brown during the baking process. For the best flavor, use freshly squeezed lemon juice. Dip the banana slices into the juice, ensuring each slice is completely covered in juice.

Preparation


How to Make Baked Banana Chips
Photo Credit Thomas Hooke/Demand Media

Arrange the bananas on a baking sheet coated with nonstick cooking spray. For even easier cleanup, cover the pan with aluminum foil and then spray the foil with nonstick cooking spray. For baked bananas with a slightly different flavor and texture, sprinkle the bananas with sea salt or kosher salt.

Baking


How to Make Baked Banana Chips
Photo Credit Thomas Hooke/Demand Media

For crispy banana chips, bake the banana slices slowly in an oven preheated to about 200 degrees Fahrenheit. Too much heat scorches the bananas and may result in chips that are burned on the outside and soft on the inside. Bake the bananas for one to three hours, depending on the desired level of crispiness. To promote even baking, flip the slices halfway through the cooking time.

Storage


How to Make Baked Banana Chips
Photo Credit Thomas Hooke/Demand Media

Before storing or eating baked banana chips, cool the bananas completely on a wire rack. Then store the banana chips in an airtight plastic or glass container or a resealable plastic bag.
www.livestrong.com

Advantages and Disadvantages of Fasting for Runners

Author BY   ANDREA CESPEDES  Food is fuel, especially for serious runners who need a lot of energy. It may seem counterintuiti...