Wood-based activated carbon manufacturing Process

Wood-based activated carbon production is designed for making activated carbon from wood-based materials. There are two basic processes of wood-based activated carbon production: physical production method and chemical production process

The physical method

Firstly, carbonize the wood at high temperature, take it out and crush it into small pieces of 5-25 mm, and then activate it with high-temperature steam in the activation furnace (activation rotary kiln).

Hot steam is introduced from the upper part of the activation furnace. During this process, activated carbon is removed from the bottom of the reaction activation furnace. The carbonization reaction is an endothermic reaction process at high temperature. The carbonization process requires to heat activation furnace temperature of more than 800 degrees, and the hydrogen and carbon monoxide produced by the reactants during combustion are heating. In practice, the carbonization reaction releases hydrogen and carbon monoxide burns to release enough heat to supplement the heat required for the reaction, and the temperature in the activation furnace is kept between 800-900 degrees, so that the activation reaction can be done without heating.

The production process of wood columnar activated carbon: firstly, grind the woody raw materials to a certain fineness (generally more than 95% through 0.08mm), add an appropriate binder (commonly used coal tar) and water at a certain temperature and knead and extrude into carbon strips; After the charcoal strips are dried, they are then carbonized and activated to become woody columnar activated carbon. Wooden columnar activated carbon products sometimes need to be pickled, impregnated, modified and other treatments according to market requirements, which have met the adsorption needs of customers.

Chemical production method

Zinc chloride can be used in a dehydration system. Immerse woody raw materials and fibers in zinc chloride solution. The hydrogen and oxygen elements in the cells of the woody structure tissue are separated in the form of water molecules and completely removed in water to form woody activated carbon.

Use industrial pure zinc chloride to prepare a pH solution of 4.6-6.6, add the wood solution to the zinc chloride at a ratio of 1:4 into the mixing tank, crush the sawdust into sawdust and dry it for later use, mix it evenly, and place it for more than 20 minutes. Soak the zinc chloride solution into the lignocellulosic cells to provide conditions for full activation.

At the bottom of the carbonization kiln, add high-temperature steam to the placed mixture from the upper end of the carbonization kiln, increase the reaction interface between high-temperature water vapor and the mixture to fully carbonize the wood. As for the carbonization kiln selection, the rotary carbonization kiln will be a better choice.

After the activation reaction, in addition to zinc chloride and wood activated carbon products as activators, there are also zinc oxide and zinc hydroxide, zinc oxide can be reduced to zinc hydroxide with dilute hydrochloric acid, and zinc chloride can be added to the next carbonization and activation process as a carbonization agent.