Ways to Utilize Your Pulp and Paper Wastes
Updated: Feb 8
The pulp and paper industry is known worldwide as one of the highest waste generating industries. Only a few percent of the wood sources made it as the final products, with a small number of wastepaper used in paper recycling. The rest is discarded to the landfill as solid and liquid waste or incinerated.
Not only does it bring no commercial significance, the damage that it inflicts on the environment could be severe if no actions are taken. Wastes generated from the pulp and paper industry harm aquatic life, disrupt the food chain, as well as cause several health issues to humans. Unfortunately, many countries, especially the developing countries, have not yet shifted to practicing sustainability considerably. Therefore, an intervention is needed to minimize pulp and paper wastes.
Pulp and paper waste management and utilization
The pulp and paper industry produces both liquid and solid wastes during production. Liquid waste in the form of wastewater is generated from various sources, such as washing of raw wood materials and washing of cooked pulp and bleaching pulp. On the other hand, solid waste is primarily the result of screening rejection, primary and secondary sludge from wastewater management, and lime sludge from the chemical recovery system. In many parts of the world, pulp and paper companies utilize both landfill and incineration techniques for waste disposals though their options might differ depending on technology and economic situation.
Landfills are the final destination of disposal for most of the solid wastes, such as sawdust and other woody matters, as well liquor dregs, grits, lime mud, and mill as after dewatering and drying. Black liquor is incinerated or turned as gas for fuel energy if the technology supports the process. If not, it will be discarded to the landfill. For energy recovery, rejects are dewatered and burned. Similar to black liquor, wastewater sludge is disposed of through incineration after it is dehydrated. The deinking sludge from the production of recycled paper could be incinerated or reused in other mills. Other wastes that are commonly incinerated are sulfate lignin, and solid wastes generated from paper and board production, such as a quantity of wood mass and cellulose, pieces of end production, and product rejects, if they could not be returned in the production cycle.
Widely applied by pulp and paper companies, landfilling poses an environmental concern with its limitations on volumes and the possibility of piling hazardous substances from the wastes. Therefore, instead of just disposing the wastes, companies devise some alternative methods to minimize wastes through recycling or reusing the wastes for various purposes. Below are some examples on waste utilization in the pulp and paper industry:
Sulfite lyte, the main generated waste from the sulfite method, could be used to make ethyl alcohol, albumen yeasts, and connecting substance
Sulfate tall soap, a secondary product in the sulfate method, could be reprocessed (decomposition with vitriol) to create tall oil for the rubber and detergent (saponaceous)
Generated mud, which mainly consists of crystal CaCO3 and CaSO4, is used for lime production and neutralization (lime-treating) on sour soils
Ashes contain well-balanced content which are beneficial in the agriculture sector as neutralizer for sour soils or for soil structure improvement. They could also be used as building materials, such as ash-glass and light filler for plastics. Fly ash is commonly used as raw material for cement for its cost-effective and eco-efficient applications and for concrete systems in hostile environments due to its durability and mechanical resistance
Incinerated black liquor could provide steam as an optional energy source
Sawdust could be recycled for paper manufacturing, used as a secondary raw material for pulp production, and as filler for bricks and cement material manufacturing
There are also prospects to turn pulp and paper industry wastes into important engineering materials. Instead of disposing of them to landfills or incineration, it is possible to extract ingredients from the biomass from pulp and paper mills through a biorefinery approach, as seen in the table below.
Type of waste
Sawdust /woody residues
Lignin is one of the essential biomasses for the manufacturing of carbon fibers, which are known as an ideal material to load extreme weight in lightweight high-performance, because aside from being available in huge amounts, lignin consists of high carbon content (around 60–65%). The challenges regarding lignin as a substitute to carbon fiber are the availability of fiber spinning technologies in some countries
Xylan, one of components that make up the hemicellulose from black liquor, which could be biorefined into lactic acid, a crucial renewable chemical building block for composing bioplastics. The challenges in the process lie on the difficulty of getting fully purified xylan with the required grade for making polymer and the lower melting point of the polylactic acid produced in the process that limits its usage for high-performance materials
Cellulose, which could be obtained from various pulp and paper waste sources, could be converted into cellulose nanocrystals (CNC) which usage is tremendous in the medical and industrial fields
Dissolving pulp could be used for the production of textile fibers. This application has a positive economic impact on developing countries in which textile material production entirely depends on using a single fiber. The challenge in utilizing pulping waste to make textile fibers is the limited availability of fiber manufacturing units in areas where there are abundant resources and the difficulty of meeting the global textile fibers demand
Innovation in Sustainability is always an interesting topic to talk about in the pulp and paper industry, especially in regards to waste management in the pulp and paper industry. Pulp and paper companies are enthusiastic in taking waste management efforts for a better environment. So, what are BMJ’s contributions in terms of waste management?
BMJ’s waste utilization effort
BMJ attempts to maximize waste utilization strategy by recycling existing materials. Without obtaining new ones, the effort has preserved a lot of energy and reduced CO2 in the production process.
Here is a list of measures that BMJ has taken from 2020–2023 to optimize pulp and paper waste management and utilization:
In 2020, BMJ attempted some improvisations and created a sedimentation tub. Nonetheless, from the operational perspective, its function was not optimal yet
In 2021, BMJ created a belt press 3 machine from used Paper Machine 2 (PM 2) rolls
In 2022, harnessing belt press 2 machine and used materials, BMJ transferred it to Raw Water Treatment Area (RWT) to create Wyne tub (sludge dryer)
For 2023, BMJ will develop a New Flocculator Design with continuous system which is improved from its previous conventional system
The pulp and paper industry may generate a hefty amount of wastes, but with appropriate strategy and advanced waste management and utilization knowledge, the wastes could be reduced to a minimum. Even better, they could be recycled and harnessed for various purposes to achieve and optimize the industry’s sustainability effort.