Specific energy consumption and carbon intensity of ceramic tablewares: Small enterprises (SEs) in Thailand

Abstract

Energy consumption and greenhouse gas (GHG) emission from ceramic tableware production in Thailand were evaluated. Activity data regarding ceramic tableware manufacture were collected from 13 small-scale ceramic tableware plants within the boundaries of gate-to-gate. The functional unit of analysis was 1 kg of ceramic tableware product. The GHG emission of ceramic tableware production per unit of kgCO2e/kg was calculated following the 2006 Intergovernmental Panel on Climate Change (IPCC) guidelines. Emission factors were taken from the Thailand Greenhouse Gas Management Organization (TGO) and IPCC databases. The SPSS independent sample t-test (IBM SPSS Statistics 22.0) was used as a statistical inferential method for comparison of energy consumption. Results showed that the energy consumptions of ceramic tableware were mainly from liquefied petroleum gases (LPG) as 19,363 MJ/tonne during the firing process (99%), followed by electricity at 243 MJ/tonne (1%) during the forming process. The average specific energy consumption (SEC) for small-scale ceramic tableware production in Thailand was 19.6 ± 4.7 GJ/tonne of product. The SPSS independent sample t-test revealed that the energy consumption in double firing plants was 10% significantly higher than single firing plants. Comparison between specific LPG consumptions and kiln loading capacities of single firing plants indicated a linear relationship, and kiln loading capacity significantly influenced the amount of specific LPG consumed. An increase in kiln loading capacity decreased specific LPG consumption. Every one kg product/m3 loading increase gave a reduction of 0.67 kg LPG/kg product. The average carbon intensity of small-scale ceramic tableware production in Thailand was 1.241 ± 0.295 kgCO2e/kg of product. The largest GHG emission was from LPG consumption during the firing process (98%), followed by electricity consumptions (1%), and decomposition of calcium and barium carbonates (1%). The average GHG emissions of double fired and single fired products were 1.340 and 1.211 kgCO2e/kg of product, respectively. Therefore, LPG consumption during the firing process was identified as the main hotspot for energy consumption and GHG emission. Increasing kiln loading capacity, reducing kiln heat leakage, and repairing ceramic insulators were recommended as good practices for energy saving which can potentially be applied to the existing small-scale ceramic tableware plants.