(100b) Water Recovery and Reuse in Soluble Coffee Production Using a Dynamic Membrane Process

Through a grant from the U. S. Environmental Protection Agency, Pollution Prevention program, we have partnered with Nestlé USA to explore the use of novel membrane technology to improve the manufacturing efficiency of soluble coffee manufacturing operations. Our case study at their Freehold, NJ factory, evaluates water recovery methods for a spray dried and freeze dried coffee manufacturing plant. The particular focus of this paper is on a dynamic / shear-enhanced vibratory field membrane method to recover water for plant operations, thus reducing operating costs and environmental footprint. This research helps address a major issue in the food manufacturing sector – the efficient use of water and waste reduction.

The production of spray dried and freeze dried coffee involves many highly complex processes that rely on large amounts of water. These operations include process water for cooling, water to be heated to produce steam, water for process equipment operations, water for intermediate production steps, and water for cleaning and sterilization. When utility generation is included, such as operation of cooling towers, water consumption can be significant.

Many of the problems associated with effective recovery, involve the separation of dissolved, colloidal, and particulate matter, to obtain water of suitable quality for reuse. Suspended and colloidal matter is one of the biggest causes of fouling and performance degradation in operating these water recovery systems. This causes additional expense, and in many cases industry abandons this approach, since it will not produce sufficient quantity and quality of water for extended periods of time. One potential solution that is described in this paper, is a vibratory-field membrane process for food/biomass waste processing.

Our study describes the benefits and limitations of this technology, and how laboratory investigations help guide industrial use and scale-up considerations. Various membrane types were evaluated to help inform decision makers based on the reuse goals. The study evaluated the overall savings and reduction in life cycle emissions for the recovery of water from a waste stream, for use in cooling tower operation. The assessment included savings, both economically and environmentally, in the reduction in fresh water intake, waste pretreatment, and final disposal. These are compared to the increased cost and operational factors of a new recovery system. The case study found that the greatest cost and environmental impact reductions were associated with the reduction in wastewater discharge. Long-term economics were more highly influenced based on equipment size. This case study is applicable to the food and beverage manufacturing sector.