Bio-energy

We mitigate the cost of energy risk by focusing on reducing specific purchased energy, improving the energy efficiency of our mills, increasing our use of renewable energy and producing and selling surplus green electricity. Focusing on green energy generation aligns with our strategic focus on deriving value from energy opportunities and in light of increasing energy prices.

Globally we have five hydro, two gas and 31 steam turbines which generate around 800MW of renewable power on 14 sites across seven countries. We also produce biogas from our effluent streams.

We continue to invest in cogeneration and self-sufficiency energy projects, amongst others:

Biomass-derived energy project at Ngodwana Mill, South Africa

An energy project at Ngodwana Mill involves the supply of biomass from local plantations which is then used as a boiler fuel to produce steam at the mill. This in turn will generate 25MW of renewable electrical energy which will be sold into the national grid in 2018.

New turbines at Tugela and Saiccor Mills, South Africa

We are investing in projects to increase our energy self-sufficiency through the installation of new turbines at the Tugela and Saiccor Mills. The turbines will produce approximately 23MW of power and contribute to increasing Sappi Southern Africa’s energy self-sufficiency from 42.3% to 57.14% by the end of 2016.

Cogeneration in South Africa

In South Africa, cogeneration helps enhance our energy self-sufficiency, presents opportunities for revenue generation and promotes energy efficiency – cogeneration offers an efficiency ratio of 80%, compared with much lower efficiencies of power utility companies.

Project Buyisa at Saiccor Mill, South Africa

Our upgrade to Saiccor Mill, which increased energy self-sufficiency by 12%, has had a major impact on performance. Spent liquor is recovered after the cooking process and concentrated in an evaporator before being used as a fuel in the recovery boilers. Because more steam is being generated from the recovery boilers, less steam from coal is required, with a resultant decrease in coal consumption of more than 4,400 tons from October 2014 to September 2015.

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 474GJ/day, resulting in reduced fossil fuel use and enables the mill to generate additional electrical power. The project is expected to avoid generating 2,210 tons of CO2 every year.

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.

Lignosulphonate is a highly soluble lignin derivative and a product of the sulphite pulping process.

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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