Recovery/upgrading of manool from Kraft black liquor

Abstract

Within the pulp and paper industry, a common problem for mills is the presence of wood extractives in the waste streams. Not only do these extractives pose a threat to aquatic life in the local waterways, but they also increase the plant's overall operating costs, as they must treat these waste streams to meet strict environmental and safety regulations. The requirement to meet these regulations forced the J.D. Irving Pulp and Paper mill in Saint John, New Brunswick to install a reverse osmosis to treat waste water streams from the Kraft Black Liquor Recovery Process to dischargeable levels. Fortunately, some of these extractives have the potential to be refined into commercially viable materials. The objective of the proposed design is to capitalize on a waste stream at the Saint John J.D. Irving Pulp and Paper mill that the plant is currently burning. The stream in question consists of water and organic extracts (2000 ppm of manool, 3800 ppm of 4-ethylguaiacol, and 400 ppm of iso-eugenol). It is desired to upgrade the manool from 2000 ppm in water to a purity of 75% at a production rate of roughly 20-25 tonnes per year. The proposed plant, which will only operate during the softwood cycle, will utilize an adsorption and desorption process for the initial extraction of manool from the water. The extraction process will then be followed by vacuum co-distillation for purification to the desired concentration of manool. Based on the chosen design, and with a flow rate from the reverse osmosis system of 10 US gpm, the proposed plant has the potential to produce 25.6 tonnes of manool per year at the desired purity. With a current market value of $375/kg of product, the plant has the opportunity to generate an additional $9.6 million in annual revenue. The design has a total capital investment of $2.22 million, with an addition annual operating cost of $1.0 million. Based on these numbers, an economic analysis suggests that the proposed design would be have a payback period of approximately 5 months, a return on investment of 274%, and an internal rate of return of 286%. As the economics indicate, the proposed design shows tremendous promise for J.D. Irving Pulp and Paper. By harnessing the value added in their waste stream, J.D. Irving has the potential to break ground into an environmentally conscious market where there is a shift in consumer demand from synthetic to natural and eco-friendly products.