Energy is a key input for our industry. Aggressively managing energy use leads to a reduction in carbon emissions and enhanced cost efficiencies.

Environmental impact is reduced by the amount of energy, and also by the type of energy consumed. We have made significant efforts to reduce our reliance on fossil fuels and increase our renewable energy usage, thereby reducing fossil-related greenhouse gas (GHG) emissions.

We continue to invest in projects aimed at achieving this, amongst others:

Biomass-derived energy project at Ngodwana Mill, South Africa

Sappi has a 30% stake in a 25 MW biomass energy unit at Ngodwana Mill which falls under the South African government’s Renewable Energy Independent Power Producer Programme (REIPPP) and which is expected to contribute to the national grid from July 2020. The project will use biomass recovered from surrounding plantations and screened waste material from the mill production process. The power plant will burn up to 35 tons per hour of biomass in a boiler to generate steam and drive a turbine to generate electricity which will be fed into the national grid. Sappi already contributes to the national grid by selling surplus energy from Ngodwana Mill to the state power utility, Eskom.

With this project, Sappi has become one of only a few companies in South Africa to embark on a biomass energy project.

Fuel rods

Some 150 years of intensive coal mining in South Africa have produced about a billion tons of discarded thermal-grade coal fines. To utilise this energy source, we constructed and tested a small fuel rod manufacturing plant at Ngodwana Mill. The fuel rods comprise a mixture of coal slurry, biomass and lignosulphonate, which can be used as a coal replacement. Initial fuel rod test results are positive and could lead to reduced greenhouse gas emissions when compared to low-grade coal. In FY2019, we began testing the fuel rods in one of Sappi’s boilers at Tugela Mill. The demonstration facility at Ngodwana Mill will be upgraded if the test results are positive.

Treating waste condensate in Europe

In many of our European mills, we generate renewable energy in the form of biogas. We are reviewing expanded use of anaerobic digestion technology as one of the technologies to treat waste condensate. Rich in organic matter, the condensate could be treated via a process which uses organic acids to produce biogas in the form of methane, which in turn could be used to produce energy, either for internal use or external sales to the national grid.

We are also evaluating the extraction of chemicals from the condensate stream.

Paper machine heat recovery at Somerset Mill, United States of America

Heat from the paper machine dryer hoods used to be vented. Equipment has been installed to recover that thermal energy, which is now being used to generate approximately 4.6 million litres of hot water per day which is used in the papermaking process.

The recovered thermal energy reduces steam demand by approximately 474 GJ/day, resulting in reduced fossil fuel use and enables the mill to generate additional electrical power. 

Globally, 53.9% of total energy consumed by Sappi is from renewable and clean energy sources.
2022 Sappi Group Sustainability Report

New developments in wood processing supports the move to a biobased economy that utilises materials that are renewable and biodegradable and that do not compete with food sources.

Sappi’s patented process, developed with Edinburgh Napier University, reduces the energy required to process woodfibres into nanocellulose thus enhancing our product’s sustainability.
Lignin is a major component of wood and is one of the most abundant natural organic wood polymers which provides a multitude of functionalities.

Lignosulphonate can be used in a wide variety of applications.

Hemicellulose sugars from trees are referred to as second generation sugars and do not compete with food crops unlike first generation hemicellulose sugars from agricultural crops.
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