Pulp & Paper

The recovery boiler is one of the most critical pieces of equipment in a kraft mill - simultaneously combusting black liquor for steam generation, reducing inorganic compounds to regenerate cooking chemicals, and destroying hazardous compounds in the spent liquor. CPE provides recovery boiler performance assessment, air system design and optimization, liquor spray system evaluation, superheater and generating bank fouling assessment, tube leak detection and response planning, and capacity assessment for mills where the recovery boiler limits pulp production.

Most kraft mills also operate biomass-fired power boilers burning bark and wood waste to supplement steam production and provide backup capacity during recovery boiler outages. CPE evaluates the mill’s steam balance with and without the recovery boiler online and designs power boiler capacity accordingly.

Kraft mills generate CNCG and DNCG streams containing the sulfur compounds responsible for the characteristic kraft mill odor. CPE designs NCG collection, transport, and incineration systems - including dedicated burners, safety interlocks, and backup destruction provisions during kiln or boiler outages.

The dryer section is the dominant thermal energy consumer on any paper machine - 40 to 80+ steam-heated cylinders arranged in groups at specific pressures to create a controlled temperature profile. CPE provides dryer section steam system design, condensate removal troubleshooting, flash steam cascade optimization, thermocompressor design, and hood exhaust heat recovery. The entire system operates as an interconnected cascade where a change at one pressure level propagates throughout - CPE models these systems to minimize live steam consumption per ton of paper.

Pulp and paper mills reject heat at dozens of points - boiler stack gas, lime kiln exhaust, paper machine hood exhaust, evaporator condensate, TMP blow steam, and compressor aftercoolers. CPE evaluates recovery opportunities on a mill-wide basis rather than equipment-by-equipment, because the highest-value projects are often not the most obvious ones.

Pulp and paper mills are the most thermally integrated industrial facilities in operation. Every piece of fired equipment, every steam header, and every condensate return line is connected to everything else - and a change anywhere propagates throughout the system. Engineering firms that treat the boiler, power generation, and mill steam users as separate projects miss the interactions that drive real performance. CPE’s approach is to understand the mill’s energy balance as a system and engineer solutions that improve the whole, not just the component.

The combination of power boiler and biomass combustion engineering, paper machine steam and condensate system design, and mill-wide emissions compliance - delivered by engineers who understand how these systems interact - is what CPE brings to the pulp and paper sector.