Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - SPOTVIEW (Sustainable Processes and Optimized Technologies for Industrially Efficient Water Usage)

Teaser

The volume of freshwater used by the manufacturing industries represents more than 25 billion m3 per year and accounts for 10% of total water consumption in Europe. Steel, Paper and Dairy sectors represent in total 36% of the water uptake from EU industries (9 billion cubic...

Summary

The volume of freshwater used by the manufacturing industries represents more than 25 billion m3 per year and accounts for 10% of total water consumption in Europe. Steel, Paper and Dairy sectors represent in total 36% of the water uptake from EU industries (9 billion cubic meters), and contribute to 18% of industrial eqCO2 emissions. The optimization of resources (including water, energy, raw materials and additives) is a key issue in maintaining competitive, sustainable production, while protecting natural environment and minimizing the climate change.

The objective of the SpotView project is to develop and demonstrate innovative, sustainable and efficient processes aimed at:
• Recovering and recycling materials and energy (heat, biogas) from process water;
• Reusing treated water to reduce discharges;
• Substituting freshwater with alternative water sources (rainwater, seawater, treated effluent).

During the SpotView project, a total of 14 existing and new technologies are assessed in simulated or operational environments to develop 9 new water management practices in the three industrial sectors. Up to 7 technology demonstrators will be selected, for deployment in real industrial environments. The processes and technologies implemented will be evaluated in terms of the environmental impacts and benefits generated by achieving the SpotView targets (20% to 90% reduction in water usage, wastewater emissions, chemicals and energy use).

Work performed

Since the beginning of the Project (Oct 2016), the consortium members carried out or started technical tasks to characterize water/effluents streams and quality requirements in the three industrial sectors. This was achieved in WP2 by extended survey and bibliographic studies on public data available, completed by process water and effluent sampling and measurement campaigns at industrial sites from five of the partners.

WP2 was also devoted to testing in realistic environment technology components that will be used for new water management strategies in order to achieve the objectives in reducing fresh water uptake, effluent discharge and heat waste:
• Selective separation processes and technologies for valuable substances recovery (Dairy and Paper industry)
• Close loop recycling and alternative water sources (all three sectors)
• Alternative process chemistry and disinfection techniques (Dairy, Paper)
• Alternative cooling/ heating technologies (Steel, Paper)

The technology components tested were:
• Pre-treatment for suspended solid removal: microflottation, sand filtration and ultrafiltration (UF).
• Salt removal techniques: reverse osmosis, ion exchange resins, capacitive deionization
• Organic substances extraction and separation: washing press, microfiltration submerged ultrafiltration, Micellar Enhanced Ultrafiltration, Elevated Pressure Sonication (EPS)
• Alternative microbial control: Biocontrol system, UF and EPS
• Alternative effluent treatment: Anaerobic/aerobic MBR
• High to Low temperature heat waste recovery with Chemical Heat Pump.

The performances reached by all technology components for each application will be used for comparison and assessment in WP5. Key Performance Indicators (technical, economic and environmental) were defined for each application and will be used to assess the impact of the project after technology demonstration in 2019, thanks to a KPI matrix.

In parallel, industrial process data, flowsheet analysis and measurement campaigns at industrial sites allowed designing process models of demonstration site. These models will be used to compare baseline scenario with some of the new water management strategies developed.

Final results

Among the new separation and treatment technologies assessed at laboratory and pilot scale, the following achievement can be already highlighted:

For application in Dairy industry:
• Submerged-type UF membranes are preferable and more effective than microfiltration and MEUF regarding compounds (protein) recovery and energy consumption. For lactose-concentrate recovery, an additional stage of nanofiltration (NF) or reverse osmosis (RO) is required.
• Applied to dairy sludge and simulant sludge, Elevated Pressure Sonication (EPS) achieves 4-6 log10 reductions in bacteria at low energy treatment 10-30 kJ/litre (c.f. 200 kJ/litre HTST). Liquid whey and solid curd products of EPS treatment showed good protein and amino acid profile with no sign of denaturing due to low thermal conditions of EPS.
• Anaerobic treatment applied to dairy effluent gives particularly high reduction in organic matter (COD) 96% ± 4). The quality of the aerobic Membrane Bio-Reactor (MBR) permeate is considered appropriate for cooling water.

For application in Paper Industry:
• Valmet Ultrafiltration for process waters recycling in Tissue mills produces permeate free from turbidity (bacteria, colloids), secondary and micro-stickies, and 50-70% less anionic trash. When the permeate is used for replacing the warm fresh water with the typical tissue machine (100-300 t/d), the Valmet Ultrafiltration process including one or two cross rotational (CR) ultrafilters can reach the fresh water reduction of 1-2 m³/t of produced paper. The benefit of Valmet Ultrafiltration CR is the low operating pressure difference and thus no clogging of the membrane. There are also savings in the energy used for heating the water and the PM processes.
• Secondary treatment effluent recycling to paper machine showers or pulp dilution tank can reduce 40 to 70% fresh water uptake. Process water conductivity increase from 2 to 6 mS/cm has no effect on Wet Strength Resins efficiency and little negative effect on DAF flocculants.
• Capacitive deionization (CDI) applied on papermaking effluent achieved 39 to 63% reduction in conductivity and 60 to 85% reduction in anions and hardness components.

For application in Steel Industry:
• Capacitive deionization (CDI) trials applied on backwash and river waters fulfilled the steel industry requirement for reduction in conductivity (< 200 µS/cm) and chlorides (<100 mg/L), with water recovery from 71% for backwash water to 79% for river waters, and energy requirement from 2.1 kW/m3 and 0.9 kW/m3, respectively.
• Sand filtration and ultrafiltration are technically suitable pre-treatments to preserve fouling of RO membranes. Two passages through RO are required to achieve inlet industrial water requirements. Water recovery above 50% is not recommended due to the flux and rejection decline.

Website & more info

More info: http://www.spotview.eu/.