Category: Economics Of Manufacturing Pollution Prevention

In July 1996, a paper company located on the west bank of the Mississippi River undertook a program to eliminate the discharge of industrial wastewater to the river. A wastewater recycling system consisting of pumps, surge tank, and filtration system reduced discharges by 99%. The successful pollution prevention includes the annual elimination of 562 million gal of…

Like the three evaporators, the two concentrators are vertical‐tube, falling‐film design. Rather than using a vapor compressor to drive the system, the concentrator is operated with steam generated by the recovery boiler. The evaporation process in the concentrators is essentially the same as in the evaporators, but the effluent is concentrated further, to about 67%…

The heart of the zero effluent system is three vertical‐tube, falling‐film vapor compression evaporators which operate as explained (Das 2005). At 100 ft tall, and with thousands of square feet of heat transfer surface, this is the largest train of mechanical vapor recompression evaporators in the world. The evaporators concentrate effluent from 2% solids to 35% solids,…

The first unit operation to receive pulp mill wastewater is the floatation clarifiers. Since removal of fiber is very important to the performance of the evaporators, the mill decided to install two clarifiers instead of one. This allows for maximum removal efficiency and flexibility. Chemicals are added to aid in flocculation and floatation of the…

The $250 million Millar Western Meadow Lake Mill is located on a 247‐acre site about 200 miles northwest of Saskatoon, Saskatchewan. It uses mechanical action supplemented by mild chemicals to turn aspen wood chips into bleached chemi‐thermomechanical pulp (BCTMP), about 240 000 MT/Y.2 More efficient than the kraft process, this approach uses half the trees to make the same amount…

Introduction Every day, water‐cooled thermoelectric power plants in the United States withdraw from 60 billion to 170 billion gal of freshwater from rivers, lakes, streams, and aquifers, and consumes from 2.8 billion to 5.9 billion gal of that water. Freshwater withdrawals for cooling in thermoelectric power production account for about 40% of all withdrawals, essentially the same amount as withdrawals for agricultural…

Sulfur is often considered one of the four basic raw materials in the chemical industry. It can be recovered as a by‐product from sulfur removal and recovery processes (Kirk and Othmer 2004). Historically, sulfur recovery processes focus on the removal and conversion of hydrogen sulfide (H2S) and sulfur dioxide (SO2) to elemental sulfur, as these species…

Methanol, formed during the pulping of wood and is contaminated with reduced sulfur compounds and terpenes, is the largest single source of VOC emissions from kraft pulp mills, accounting for 70–80% of total emissions. The Cluster Rule (Cluster Rule Regulation: 40CFR Part 63 1998) limits methanol emissions for all pulp mills in the United States. Canada…

A cost comparison was made for two most promising processes – replacing chromate conversion coating and zinc phosphatizing. These were chosen based on the potential cost savings that industry could achieve. There would appear to be a significant economic incentive to migrate existing practice to this new technology, based on the significant capital and annual…

The USEPA recently completed a study of the proprietary Picklex process. Picklex® is a “‘non‐polluting’ pretreatment/conversion coat which replaces chromate conversion coating and zinc & iron phosphatizing in powder coating, paint and other organic finish applications” (Ferguson and Monzyk 2003; Ferguson et al. 2001). Description Metal pretreatment is crucial for cleaning and oxide removal to obtain proper…