Carbon Footprint and Recycling Design of Industrial Water Network in Delta Area of Yangtze River: A Simulation Based Methodology
China’s rapidly development has consumed considerable amount of water resource. Industry, which occupies more than one-fourths of water consumption and half of energy use in China, is a significant target to research towards water saving and CO2e reduction.
To save water and cut CO2e simultaneously, a feasible way is to employ carbon footprint accounting tools into WAP solutions. The accounting work should include CO2e from three parts: construction, water use reduction and piping power consumption. The accounting results should act as a constraining condition in Mathematical Programming as well as a limit theorem in theorem based WAP. The problem to this employment is water-carbon balancing issue. In particular, a standard is required to identify to water streams which should not be accepted due to CO2 emissions.
In Nanjing Titanium Pigment Factory, the water network could be designed to achieve 39.7% water saving directly, or 39.6% with treatment. After CO2e considered, the best scheme is selected as one under directly reuse principle which saves water by 39.6% and cut CO2e by 9.0%. In the whole Nanjing Chemical Industry Park, WAP solutions could achieved 66.9% water saving. Nevertheless that scheme is infeasible due to CO2e increase by 68.5%. As a substitution, modified scheme rejected two companies in the network did achieve reducing water use and CO2e by 24.3% and 9%.
WAP solution validity scale enlargement is also attempted. However it seems limited by distance. For long way water piping causes too much power use and carbon emission. At this stage scale extension seems not to be a hopeful developing direction.