Synthos Dwory cogeneration boiler room

Heat power recovered: 14.3 MW
Application: chemical plant
Location: Poland
Customer: Synthos Dwory Sp. z o. o.

Synthos Dwory Sp. z o.o. - part of Synthos S.A. is one of the largest manufacturers of raw materials for chemical manufacturing in Poland.

Hot steam and electricity for the manufacturing processes were produced on site. Along with the factory’s development the demand for energy had gradually increased, eventually exceeding the existing capabilities. Market research for available solutions concluded that modern combined heat power (CHP) installation is the best option. The main contractor was ZE ZEN Sp. z o.o.. INTECH’s task was to design and supply thermal energy recovery system and to supervise an implementation process.

After a thorough analysis of available technologies, three Jenbacher gas engines with electricity generators and Clayton Exhaust Gas Boilers (EGB) were chosen as a solution, completely satisfactory for customer’s needs.

Although a cogeneration process is fully described in a separate article, it is worth to delineate a principle of operation of CHP plant of the customer. As main devices for exhaust’s energy recovery - three 7-sectional Clayton EGB with economisers were applied. They are cooling down exhaust gases from 451 °C to 158 °C. Energy is than stored in two Lamont tanks with total capacity of 10 m³. Energy recovered: 4.35 MW.

For the best performance GEA exchangers (so-called wet economizers) were mounted at outlets of Clayton Boilers. This solution serves for additional energy scavenging - cooling exhaust gases below the dew point (approximately 63 °C). Energy recovered: 2.55 MW.

Thermal energy is also obtained from glycol coolant, that passes through the engine block in two independent circuits - high- and low- temperature. In both circuits the coolant is adequately cooled from 94 °C to 74 °C and from 53 °C to 45 °C. This solution minimised a use of standard air exchange engine cooling system. Energy recovered: 7.37 MW.

Gas engine itself requires lubrication. A system, based on four oil tanks with a total capacity of 6 m³ was specially prepared for this task. Boiler feed water is prepared in the factory’s treatment station. Water was subjected to softening process, heat treating (two deaerator tanks - 2m³ and 4m³), chemical treating and reverse osmosis.

An additional task for INTECH was a selection of actuators and Control and Measurement Instruments. At a final stage of the investment, the customer gained a visualization and management system consisting of HMI and PC. Several PLC have supervision over the plant’s workload.
Majority of described elements and other necessary parts of the system (vessels, exhaust flaps) were made by IWT Intech in Gdansk. Assembly works were entrusted to local installation and construction companies.

In this process saturated steam reaches 210 °C / 4 bars. In order to compensate its parameters before introducing to an existing steam duct, it has to be superheated. The process takes place in a Vahterus exchanger where steam from the primary power plant is a heat source.

One of the reasons for which the customer chose a cogeneration installation was easily accessible natural gas from drainage of a neighbour mine. Energy production in cogeneration is also highly profitable in biogas power plants, which in recent years have become increasingly popular. An example of this might be a biogas plant in Mełno, which is also based on gas engines and Clayton EGB boiler.