Chem Memo #2 - Paper Making

Chemical Reactions: Paper Making

Paper is a thin material produced by pressing together moist fibres derived from wood, rags or grasses, and drying them into flexible sheets. When manufacturing paper, the chemicals used are chlorine, chlorine dioxide, sodium hypochlorite, oxygen peroxide, and ozone.

Now onto the actual process. The kraft pulping process is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibers, the main component of paper.

Kraft pulping process:

1. Lignin reacts with with sodium hydroxide (NaOH) and forms sodium lignate.
2. The sodium lignate dissolves in water which causes the fibres to seperate
3. Na-lignate is burned with sodium sulphate in a furnace.
1. Carbon portion of Na-lignate burns and provides heat energy.
2. Na-ion oxidizes the sodium carbonate (Na2CO3).
3. Sodium sulphate is also reduced to sodium sulphide (Na2S).
4. Sodium carbonate (Na2CO3) is made to react with lime or calcium hydroxide (Ca(OH)2).
1. Reaction produces NaOH and CaCO3 (limestone).
2. Calcium hydroxide (Ca(OH)2 and CO2) is given back since calcium carbonate is burned (CaCO3)
5. When bleaching, residual lignin reacts with a bleaching chemical. This provides either a water soluble compound or a colourless modified lignin.
1. If chlorine based bleaching agents are used, lignin-cl is formed
2. If oxygen based bleaching agents is used, the lignin is modified and does not dissolve in water and stay with the pulp.
6. In acidic sizing, which is the process of making paper liquid resistant, Rosin (C19H29COOH), a natural resin from pine trees reacts with alum (aluminum sulfate {A12(SO4)3}) to create aluminum rosinate, which is a liquid resistant layer around fibre.

Reactants or products of the pulp and paper production process may affect the health of people living near the plant. To bleach the pulp, chlorine compounds are used in some paper mills in preparation for papermaking. As important as this step may be, chlorine compounds are known to be the most hazardous industrial chemicals in large quantities. Some chlorine compounds produce harmful byproducts called organochlorines. Organochlorines include dioxins and other similar compounds that are known to cause cancer, as well as causing developmental, reproductive, and immune system damage. Close neighbors to the mill may experience eye and breathing irritation or nausea and headaches. People with asthma should not neighbour mills and are at a major risk of having a heart attack.

To conclude, this process is clearly unsafe for humans and their health.

Leaching of chemicals from tailing ponds affect the water quality in a local community since chemicals such as cyanide, leach into groundwater. This is very dangerous because if you were to drink cyanide, your cells would be prevented from using oxygen; without oxygen, cells die.

This is most harmful to the heart and brain.

Symptoms from drinking cyanide include:

• Nausea and vomiting
• Weakness
• Rapid heart rate and/or breathing

Large amounts can cause:

• Loss of consciousness
• Lung injury
• Permanent brain, nerve, heart damage
• Death

If this were to happen, this would result in closed water supply. When water supplies close, more water bottles will be consumed, resulting in additional wastes and water pollution. Plants that come in contact with water would die. Also, contaminated water is toxic to fish and waterfowl.

To sum it up, if leaching of chemicals from tailing ponds affect the water quality in a local community, a ripple effect of errors will occur.

There are 3 major effects to show how toxic chemical fires affect local communities.

• Health of the community
• Cancer and respiratory problem

• Health of the environment
• Soil water and air

• Economy  
• Damaged facilities/property, people without jobs, insurance

Chemicals produced by the fire also contribute towards health effects.

• Lead: neurological damage
• Arsenic: cardiovascular problems
• Cadmium: kidney problems
• Mercury: nervous systems damage

Overall, it is safe to say that paper mills can have a negative impact on the health and safety of local populations.

“Chemical Reactions: Paper Making.” Chemistry, 21 Jan. 2018, 1keetingemichemistry.wordpress.com/2018/01/21/chemical-reactions-paper-making/.