Gijsbert Korevaar

Composting, anaerobic digestion and biochar production in Ghana. Environmental-economic assessment in the context of voluntary carbon markets.

In some areas of Sub-Saharan Africa appropriate organic waste management technology could address development issues such as soil degradation, unemployment and energy scarcity, while at the same time reducing emissions of greenhouse gases. This paper investigates the role that carbon markets could have in facilitating the implementation of composting, anaerobic digestion and biochar production, in the city of Tamale, in the North of Ghana. Through a life cycle assessment of implementation scenarios for low-tech, small scale variants of the above mentioned three technologies, the potential contribution they could give to climate change mitigation was assessed. Furthermore an economic assessment was carried out to study their viability and the impact thereon of accessing carbon markets. It was found that substantial climate benefits can be achieved by avoiding landfilling of organic waste, producing electricity and substituting the use of chemical fertilizer. Biochar production could result in a net carbon sequestration. These technologies were however found not to be economically viable without external subsidies, and access to carbon markets at the considered carbon price of 7 EUR/ton of carbon would not change the situation significantly. Carbon markets could help the realization of the considered composting and anaerobic digestion systems only if the carbon price will rise above 75-84 EUR/t of carbon (respectively for anaerobic digestion and composting). Biochar production could achieve large climate benefits and, if approved as a land based climate mitigation mechanism in carbon markets, it would become economically viable at the lower carbon price of 30 EUR/t of carbon.

Comparing industrial symbiosis in Europe: towards a conceptual framework and research methodology

Industrial symbiosis (IS) continues to raise the interest of researchers and practitioners alike. Individual and haphazard attempts to increase linkages among co-located firms have been complemented by concerted efforts to stimulate the development of industrial regions with intensified resource exchanges that reduce environmental impact. Additionally, there are examples of both spontaneous and facilitated linkages between two or more firms involving flows of materials/energy waste. A striking feature of IS activities is that they are found across diverse social contexts and vary considerably in form (Lombardi et al., 2012); there are substantial differences in the ways in which IS manifests itself. Equally diverse are the activities of policy makers to stimulate such linkages. Such diversity can already be found within Europe, as became apparent in a first meeting among some of the present authors in 2009 (Isenmann and Chernykh, 2009). Researchers present there decided to create a network of European researchers on IS, with the explicit aim to develop a comparative analysis. We can thus provide insight to the relationship between the style of IS and its context and thereby the potential for policy makers in different contexts to learn from each other. Policy learning can be a tempting route to IS, but is fraught with difficulties if the influence of context is not appreciated (e.g., Wang et al., Chapter 6, this volume).