Industrial Process Heat: case study 10 – Replacing coal with biomass at Golden Bay Cement, New Zealand
The use of biomass for energy in industry is growing rapidly in the last 15 years or so. Until about 2010, the use of biomass residues for process heat in industry was originally limited to industry sectors that had their own residues available to cover (some of) their own heat demand, e.g. sugar, palm oil, wood processing, pulp and paper, etc. By processing these residues, a waste problem could be avoided while generating useful heat at the same time. With the increasing demand for cost effective renewable heat, other industries have also recognized the opportunity for biomass based heat provision to reduce the carbon footprint of their processes.
Cement is the second most consumed material in the world, following water, with no scalable substitutes at present. Manufacturing cement results in two main sources of carbon dioxide (CO2) emissions, which account for about 6% of all man-made emissions, second only to the steel sector. Approximately, 40% of these emissions arise from burning fossil fuels to heat kilns to 1350-1450°C; the balance produced during the thermal decomposition of limestone into CO2 and lime, an essential element of cement.
Golden Bay Cement is one of New Zealand’s two main suppliers. In 2025, they had approximately 60% alternative fuels firing and 40% coal, which has allowed them to reduce CO2 emissions by 75,000 tonnes per annum compared to firing coal only. They plan to fire 100% alternative fuel by 2030, which forms part of the strategy to reduce their carbon footprint by 30%, from 2018 levels by 2030.