Membrane activities

Membrane processes had been commonly seen as very expensive comparing with conventional ones, but in the last years that opinion has been remarkably changed.

I. There are some applications of membrane pressure driven techniques in power plants made first of all by Zenon Company. Power Plants are a large consumers of water for boiler make up, cooling systems and warm water for heaters. Such water must have high quality, especially concerning conductivity and content of organics. For production of demineralized water membrane processes are introduced, first of all RO, ED, UF and MF.

In Poland there are several installations for treatment of water for power stations:

• Power Station in Lagisza - installation (operated from 1997) for demineralized water (250 m³/h) for 7 turbines (125 MW each) from water coming from cooling system. Technological system includes filter (250 mm), microfiltration (3x90 m³/h ) and reverse osmosis (3x50 m³/h). The water quality:conductivity 0. 2 mS/cm, SiO₂ content < 0,02 mg/dm³.

• Power Station - Zeran at Warsaw - system for production of warm water for heaters (250 m³/h) contains pretreatment (chlorinating, decarbonisation and coagulation) filtration on graveler and sand - hard coal filter sand two stage reverse osmosis. The installation is in operation from 1995.

• Power Station at Katowice - Zenon microfiltration installation for the treatment of secondary sewage for cooling system.

II. The main surface water quality problem in Poland is caused by the high volume and mineral load of brackish water discharge from all kinds of mining activities, and in particular from coal and copper industries. Therefore, with a great attention should be followed the original brackish water desalination technology elaborated in large international collaboration by Central Institute of Mining at Katowice in Debiensko Plant. The yield of this installation is 300 m³/h and produces sodium chloride for both food and industrial purposes. In 1995 a desalination installation eliminating saline waters from coal mines "Debiensko" and "Budryk" (Poland) was brought into operation. The installation is based on reverse osmosis, to obtain high - quality potable water, and on evaporation methods, to bring about the elimination of all salts from the water. With full operational capacity, the plant will be processing 24 m³/day of mine waters of the salinity level ranging from 8000 to 115000 mg/dm³. The day production of potable water is to amount to 9000 m³, 4000 m³ of condensate from distillation, almost 300 ton of salt (99.8% NaCl) and a number of other chemicals. The installation consists of the following elements:

• pretreatment of mine waters,

• reverse osmosis together with the station for potable water preparation,

• thermal evaporation and crystallisation,

• recovery, drying and cooling of the salt,

• recovery, cooling and utilisation of postcrystallisation lyes.

III. Also there are two installations which produce drinking water from low salinity mine water as the raw water. Nanofiltration installation has been applied to remove the excess of sulfate ions from water. The installations are located in the south part of Poland near Katowice:

• water Treatment Plant at Rydultowy - Rybnik

• water Treatment Plant at Nowa Ruda - Katowice

IV. MTR Inc. (USA) together with its partner company AMERPOL (Wloclawek) introduced two succesfull membrane applications for the removal of organics from off-gases (recycling of mono-vinyl chloride - Anwil S.A., Wloclawek, recycling of ethylene - Orlen S.A., Plock).

V . There are some companies dealing with production and distribution of installations for membrane filtration operations:

Industrial group EURO - SEP (Warsaw) - production and design of membrane systems, designed over 20 industrial size filtration plants.

Enterprise OBRAM - DAIRY (Warsaw) - distribution of membrane installations with ceramic membranes from TAMI Industries.

INTERMASZ (Wrzesnia - Poznan) - distribution of membrane installations with ceramic membranes from TAMI Industries.

ZENON Systems Kft., division at Tychy - Katowice - membranes for reverse osmosis, nanofiltration and ultrafiltration (immersed capillary membranes).

PROMINENT (Wroclaw) - installations for membrane filtration.

There are several SME companies that implement membrane technologies to industry. However most of them are the representatives of large companies and offer the solutions based on the mother company systems. Two years ago, Technological Park of Faculty of Chemical and Process Engineering, WaUT, established Polymem Ltd - the company that bridges university and industry. The characteristics of the company one can find on its web page (www.polymembranes.com)‚ Polymem Ltd offers a range of products and services related to sub-micron filtration. As well as supplying complete filtration systems, utilizing a range of membranes [including those manufactured of ceramic materials], we manufacture polypropylene and polysulphone capillary membranes for our in-house use and also for any incorporation to any equipment of customer’s system.

Preparation of UF (polysulfone and polyether-sulfone) and MF (polypropylene) membranes offers the wide range of filtration capillaries. The membranes are fixed in the standard modules: 25 mm diameter (0.2 m² ), 50 mm diameter (1 m²), 75 mm diameter (2 m²), 100 mm diameter (3 m²), 300 mm diameter (30 m²) that shells can be made from: glass, steel, PP or PVC.

The company can tailor various modules according to different customer requests.

The following services are also available:

• process engineering,

• system design,

• system manufacturing and assembling,

• design and construction of automated control systems,

• system service and project management.