Can you use biomass instead of coal?

Biomass - icon Vattenfall is increasing its combustion of biomass to replace coal in generation of electricity and heat, thereby reducing CO₂ emissions from our existing plants and increasing our use of renewable energy sources.

Biomass presents unique opportunities for addressing sustainability concerns – but also unique challenges.

With respect to greenhouse gas emissions and climate change, biomass is the best near-term option for reducing the impact of existing fossil fuel-fired power and heat plants. The most common types of biomass used for electricity and/or heat production can contribute towards a reduction of CO₂ emissions by 55-98 per cent over fossil fuels when the whole supply chain is taken into consdieration .

This can be achieved relatively simply and effectively through co-firing – substituting biomass for a part of the coal used in existing plants. The challenge lies in ensuring a sustainable supply chain that limits negative environmental or social impacts – particularly when sourcing from developing countries. This requires laws, regulations and legal frameworks that safeguard social and environmental sustainability aspects. A sustainable life cycle also contains re-plantation of biomass.

Vattenfall and biomass

Vattenfall is already one of the world’s largest purchasers of biomass for power production. The biomass used by Vattenfall is comprised primarily of household and industrial waste (over 60 per cent) and forestry industry residue (30 per cent). The remainder is comprised chiefly of agricultural residues. Today, over 40 of Vattenfall’s heating and power plants are powered entirely or partially by biomass and Vattenfall uses a total of three million tonnes of biomass per year.

If biomass is to increase its share in the energy mix, today’s use of waste and residues will not be enough. One major challenge is finding suppliers that can provide large amounts of biomass that meets sustainability and affordability requirements. There are still no internationally-accepted criteria defining sustainable bioenergy. Related standards and guidelines from the Forest Stewardship Council and the Programme for the Endorsement of Forest Certification schemes exist, and work on an ISO standard is ongoing.

However a standard approved for use in an energy industry context is still needed. The goal is to establish a functioning system that guarantees that biomass production is carried out in a way that limits environmental and climate impacts, regardless of whether the product is domestic or imported. Such a system must also take all involved parties into account – from local residents of the producing country to the energy companies that purchase biomass.

Sourcing sustainable biomass – Rubber trees from Liberia

Vattenfall needs to source biomass in volumes not now available locally. We are developing a portfolio of projects to achieve this, and one attractive option, both economically and environmentally, was the use of unproductive rubber trees from plantations in Liberia.

Liberia is a country with a large resource of rubber trees, with rubber export a key component in plans to revitalize the economy. These cultivated trees typically produce latex between the ages of 7 and 30 years, after which they are harvested and replaced by newly planted trees.

The practice has been to let these harvested trees rot or to burn them on site, with some of the wood used for charcoal production. In 2010 Vattenfall, began purchasing wood chips made from the trees that are no longer producing rubber, and which would in any case be disposed of.