BleachingTechnologies & Measures
|Technology or Measure||Energy Savings Potential||CO2 Emission Reduction Potential Based on Literature||Costs||Development Status|
|Improved Brownstock Washing||Estimated energy savings can be as much as 001 GJ/ton of production. Electricity savings may be around 12 kWh/ton of production (Kramer et al., 2009. p.93).||Commercial|
|Heat Recovery from Bleach Plant Effluent|
In one US based plant, energy savings are estimated to be 939 000 GJ/year (Kramer, et al., 2009. p.92).
|In the same US based mill, corresponding annual cost savings are $2.4 million (2003 dollars). At the capital investment of $1.6 million, the payback period is estimated as 0.7 years (Kramer, et al., 2009. p.92).||Commercial|
|Secondary Heat Use for Chlorine Dioxide (ClO2) Pre-heating|
In one study, for a mill producing 1 000 ADT of bleached pulp, where Kappa value to bleaching is 30, where a ClO2 concentration of 9.5 g/l is used, and where ClO2 is heated from 2.8 to 43.3 C, 0.59 GJ/ADT of energy savings were estimated by using secondary heat in preheating (NCASI, 2001. p. 77).
For the same mill studied a net CO2 reduction of 12 625 t-CO2/year has been estimated.
For the plant corresponding to 0.59 GJ/ADT saving, annual cost savings of $430 900 (2001 dollars) were estimated. Capital costs are largely due to the cost of heat exchanger and piping (NCASI, 2001. p.77).
For another plant, savings in fuel, electricity, and steam were estimated at $61,000, while capital costs were estimated at $124,000 (2003 dollars) ((Kramer et al., 2009. p.93).
|Washing Presses||Savings from reduced steam consumption are estimated as 0.38 GJ/t pulp (Martin et al., 2000. p.30).||Operation cost savings from lower chemical use will be approximately $0.53/t pulp. Capital cost with pre- and post-lignification process equipment has been estimated as $6 million for a plant of capacity 900 tpd (Martin et al., 2000. p.30).||Commercial|