Cogeneration system for energy saving and CO2 emission reduction: A case study of textile factory

Thailand has many textile factories of which the complete value chain consists of upstream, midstream and downstream sectors. It is well-known that textile manufacturing consumes considerable amount of energy. The textile factory in this case study is located at Bang Poo Industrial Estate in Samut Prakarn province, Thailand. It is categorized as a midstream sector and has been consuming final energy in terms of 87% thermal energy (steam) and 13% electrical energy. The factory had 6 fire-tube steam boilers having capacity of 40 tons steam per hour. The age of the existing boilers was longer than 20 years. Therefore, it was decided to install a cogeneration system to replace the existing boilers for energy saving, safety integrity and CO2 emission reduction. The gas turbine topping cycle cogeneration system with waste heat recovery was selected due to several advantages such as low energy consumption, high boiler efficiency and high energy efficiency. Considering the energy and environmental issues, the results showed 92% overall efficiency, 19.5% primary energy or natural gas savings, and 38.6% reduction of CO2 emission when compared to the separated heat and power system. In summary, the cogeneration system shows positive energy and environmental impacts.