Waste management evaluation of green generation from selected facilities owned by a chicken producer in South Africa

Abstract

Poultry production is among the fastest-growing livestock sector in the world, growing at an average of 3% per year (FAO, 2020). In South Africa, this sub-sector is the largest agricultural sector in the country contributing 20 % of all agricultural production in terms of rand value (SAPA, 2019). This subsector was projected to increase by 4 %, reaching 1.57 million tonnes in 2021. However, this huge increase in poultry production has also come at a cost to the environment due to an increase waste production related to poultry processing. The most problematic waste noted was the generation of about 100 tonnes daily of high COD wastewater sludge (~100000 mg/l) obtained from treatment of wastewater. This waste is highly polluted, and without the correct disposal, it poses serious risks for public health and the environment. For one of the major poultry meat producing companies in the country, this challenge initiated construction of two waste to value (W2V) plants aimed at converting this waste into bioenergy. However, the performance assessment of these W2V plants in terms of their technical, economic, and environmental benefits has never been performed. The objective of the study was therefore to evaluate the waste generation and disposal at the processing plants and the performance of the W2V plants in terms of their bioenergy generation based on the feed used. A mixed method research approach involving interviews and document collection of performance data was used to address the objectives of the study. The results of the study showed that the W2V projects have had positive impact on the environment in terms of water and air quality, reduced reliance on coal and external power for heating, and reduction of landfilling. The bioenergy plant produced enough electricity to power 20-30 % of the processing plant’s energy needs. In addition, the W2V plants resulted in economic benefits of up to 10 % on the carbon tax due to the offsets as a result of bioenergy production, as we all as profits from export of electricity to the grid of about R4.9 million annually. The study observed that on technical performance of the plants, the two plants are not yet running at optimum levels, producing about 50 % of the capacity currently.