More than 150 pulp mills across the
Unfortunately, the unwanted methanol and mercaptans has often been discharged into nearby streams and rivers, creating a negative environmental impact. Residents close to such mills complained about the foul odors from the mercaptans and ammonia. In response, the industry adopted incineration or holding ponds (where bacteria would consume the undesirable compounds) as options to treat the waste.
The problems with those methods included excessive carbon dioxide emissions (a greenhouse gas) and sulfur dioxide emissions, which leads to acid rain.
A major pulp and cellulose products company in the Southeast patented a process that oxidizes methanol and mercaptans in mill waste into formaldehyde. Subsequently, the formaldehyde can be sold to make adhesives and scratch-resistant coatings. The impediment to this process is the rapid rate at which expensive catalyst fouls.
The client turned to MPT to help solve the catalyst fouling problem. MPT determined the catalyst fouled rapidly due to metal ions in the methanol feed stream. MPT developed special sorption media to selectively remove contaminants such as iron, zinc and aluminum. MPT designed and installed an integrated system to treat the methanol feed and thereby extend the life of the catalyst. The exhausted sorption media is returned to MPT for regeneration and fresh media is supplied to keep the process operating at full capacity.
MPT’s advanced separation technology extended the life of the formaldehyde catalyst, significantly enhancing the process profitability. This process became a standard procedure for treating the waste from the wood chip digestion process. In this case, the client improved its operations, its bottom line and the environment.