Charcoal

From Cargo Handbook - the world's largest cargo transport guidelines website
Jump to: navigation, search
Infobox on Charcoal
Example of Charcoal
Charcoal-1.jpg
Facts
Origin -
Stowage factor (in m3/t) 2,7 m3/t (bulk)
Humidity / moisture -
Ventilation -
Risk factors See text

Description

Charcoal is a substance obtained by partial burning or carbonization (destructive distillation) of organic material. It is largely pure carbon. The entry of air during the carbonization process is controlled so that the organic material does not turn to ash, as in a conventional fire, but decomposes to form charcoal.

The most common variety of charcoal, wood charcoal, was formerly prepared by piling wood into stacks, covering it with earth or turf, and setting it on fire. In this process volatile compounds in the wood (e.g., water) pass off as vapors into the air, some of the carbon is consumed as fuel, and the rest of the carbon is converted into charcoal. In the modern method, wood is raised to a high temperature in an iron retort, and industrially important byproducts, e.g., methanol (wood alcohol or wood spirit), Acetone, pyroligneous acid, and Acetic Acid, are saved by condensing them to their liquid form. Air is not really needed in the carbonization process, and advanced methods of charcoal production do not allow air to enter the kiln. This results in a higher yield, since no wood is burned with the air, and quality is improved. Charcoal is also obtained from substances other than wood such as nut shells and bark; that obtained from bones is called bone black, animal black, or animal charcoal.

Charcoal yields a larger amount of heat in proportion to its volume than is obtained from a corresponding quantity of wood and has the further advantage of being smokeless. The greatest amount is used as a fuel. Charcoal is often used in blacksmithing, for cooking, and for other industrial applications. One of the most important applications of wood charcoal is as a component of gunpowder. It is also used as a reducing agent in metallurgical operations, but this application was diminished by the introduction of coke. A limited quantity is made up into the form of drawing crayon. Bamboo charcoal is the principal ingredient in sumi-e, a form of Japanese ink painting that uses only black ink in various concentrations.

Because of its porous structure, finely divided charcoal is a highly efficient agent for filtering the adsorption of gases and of solids from solution. It is used in sugar refining, in water purification, in the purification of factory air, and in gas masks. Wood charcoal can remove coloring agents from solutions, but this is accomplished more efficiently by animal charcoal. By special heating or chemical processes the adsorptive property can be greatly increased; charcoal so treated is known as Activated Charcoal.

Under normal circumstances, charcoal after production will absorb up to 5% of moisture unless actually subjected to soaking or standing out in rainy weather when it can absorb up to 20%. Simple drying of the material at a low temperature will remove the water. May also be subject to loss in weight, probably by loss of moisture. Charcoal, being absorbent, can be contaminated by any material carried in the water, such material possibly staying in the charcoal permanently. Ideally, charcoal should be kept in sacks or similar containers raised from the floor on pallets or duckboards and sheeted over. Paper bags are subject to the normal problems when they are wet or torn.

Commercial charcoal is found in either lump, briquette, or extruded forms:

  • Lump charcoal is made directly from hardwood material and usually produces far less ash than briquettes.
  • Briquettes are made by compressing charcoal, typically made from sawdust and other wood by-products, with a binder and other additives. The binder is usually starch. Some briquettes may also include brown coal (heat source), mineral carbon (heat source), borax, sodium nitrate (ignition aid), limestone (ash-whitening agent), raw sawdust (ignition aid), and other additives like paraffin or petroleum solvents to aid in ignition.
  • Extruded charcoal is made by extruding either raw ground wood or carbonized wood into logs without the use of a binder. The heat and pressure of the extruding process hold the charcoal together. If the extrusion is made from raw wood material, the extruded logs are then subsequently carbonized.

The characteristics of charcoal products (lump, briquette, or extruded forms) vary widely from product to product. Thus it is a common misconception to stereotype any kind of charcoal, saying which burns hotter, etc.

Activated Carbon, also called activated charcoal, Activated Coal, or carbo activatus, is a form of carbon processed to be riddled with small, low-volume pores that increase the surface area available for adsorption or chemical reactions.

Due to its high degree of microporosity, just one gram of activated carbon has a surface area in excess of 500 m2, as determined by adsorption isotherms of carbon dioxide gas at room or 0.0 °C temperature. An activation level sufficient for useful application may be attained solely from high surface area; however, further chemical treatment often enhances adsorption properties.

Activated carbon is usually derived from charcoal. Activated carbon is used in gas purification, decaffeination, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in gas masks and respirators, filters in compressed air and many other applications.

One major industrial application involves use of activated carbon in the metal finishing field. It is very widely employed for purification of electroplating solutions. For example, it is a main purification technique for removing organic impurities from bright nickel plating solutions. A variety of organic chemicals are added to plating solutions for improving their deposit qualities and for enhancing properties like brightness, smoothness, ductility, etc. Due to passage of direct current and electrolytic reactions of anodic oxidation and cathodic reduction, organic additives generate unwanted break down products in solution. Their excessive build up can adversely affect the plating quality and physical properties of deposited metal. Activated carbon treatment removes such impurities and restores plating performance to the desired level.

Shipment / Storage

Charcoal is sometimes packed in bags, baskets, or made up into trusses. However, usually it is shipped in bulk. Very dusty and light cargo: protect fine cargo from dust when handling. Oak charcoal is fairly heavy. Beware coconut husks which may be shipped as charcoal. Not permitted for transport in bulk if class 4.2. If carried in bulk must be accompanied by a certificate from shipper stating cargo is not class 4.2 based on definitive test. Stow clear of all chlorates, and not over any cargo liable to be damaged by charcoal dust. This cargo absorbs moisture equal to about 18-20 per cent, of its weight.

More information on charcoal/Carbon
These commodities can be either hazardous (IMO regulated) or non hazardous

Carbon, charcoal and associated products offered as non hazardous
The manufacturer/shipper must prove in writing that the product offered for shipment meets the IMO requirements for non hazardous cargo. When a shipper offers these products as non hazardous the following procedure needs to be followed.

Check to see if the manufacturer is on the list "Approved manufacturers", which certain carriers are maintaining in their cargo acceptance policy.

If the manufacturer is on this list:

  • Check that the product offered is exactly the same as that described under "Description".
  • Obtain a laboratory certificate, as specified in IMO special provision 925
  • Check that the laboratory certificate is applicable to the customer, the cargo being offered and is less than 12 months old and shipment is prior to the expiry date on the list.
  • Check that the laboratory certificate does state that the product has passed the required tests and is non hazardous (test for self heating substances)
  • Check that the laboratory is accredited by the Competent Authority (obtain this information from the Competent Authority)
  • Check that the manufacturers name is shown on the laboratory certificate in English as this certificate has to accompany the shipment

If all above is correct then the cargo is acceptable as non hazardous If any of above does not match then treat as if the manufacturer is not on the list

If the manufacturer is not on the list :

  • Obtain a MSDS from the shipper
  • Obtain a laboratory certificate, as specified in IMO special provision 925
  • Check that the MSDS and the laboratory certificate are from the same manufacturer and for the same product
  • Check that the laboratory certificate is applicable to the customer, the cargo being offered and is less than 12 months old
  • Check that the laboratory certificate does state that the product has passed the required tests and is non hazardous (test for self heating substances)
  • Check that the laboratory is accredited by the Competent Authority (obtain this information from the Competent Authority)
  • Check that the manufacturers name is shown on the laboratory certificate in English as this certificate has to accompany the shipment

The laboratory Certificate must accompany the shipment, after stuffing of the containers the container numbers that are applicable are to be added to the certificate (hand written is acceptable) and placed on board the vessel and send as an Email attachment to the load and transhipment port.

These Products may be known under various names including but not limited to the following:

  • Charcoal animal or vegetable origin
  • Carbon Black or bone black
  • Carbon activated
  • Charcoal, non –activated
  • Charcoal activated
  • Charcoal, briquettes
  • Carbon, steam activated
  • Lamp black
  • Coke
  • Coke fines
  • Graphite

It is possible that all these above products can also be hazardous

Non IMO regulated

If these products comply to certain criteria then they can be accepted as non hazardous (Non IMO regulated) To be considered as Non IMO regulated they have comply with special provision 925 of the IMDG Code, see below

The provisions of this Code do not apply to:

  • Non-activated carbon blacks of mineral origin;
  • A consignment of carbon if it passes the tests for self-heating substances as reflected in the UN Manual of Tests and Criteria (see 33.3.1.3.3), and is accompanied by a certificate from a laboratory accredited by the competent authority, stating that the products to be loaded has been correctly sampled by trained staff from that laboratory and that the sample was correctly tested and passed the test; and
  • Carbons made by a steam activation process.

Risk factors

Reference is made to the relevant IMO regulations of hazardous cargo