Project: Supercritical Aqueous Reforming of Moist Sewage Sludge a sustainable Energy Concept for Sewage Treatment Plants (STPs)
This project develops a zero neutral energy sewage treatment plant (STP) using SuperCritical Aqueous Reforming (SCAR) of sewage sludge at 600C and 300 bar and tail water, mineral and nutrient recycling._x000D_The EC27 currently has 25.000 larger STPs that consume large amounts of energy to purify the waste water, while generating un-wanted fractions and end-products (sludge, salts) in the amount of 10 Million tons (2009). The current plants recover only 25%-40% of the energy from anaerobic digestion, but this project will seek 100% energy recovery through the supercritical aqueous reforming (SCAR) of the different sludge fractions and conversion into fuel gas to power the treatment plant. _x000D_European water technology market is 97 billion Euro/y. Up to 50% concerns waste water of which 70% is sludge-related and equal to 34 billion Euro/y. The sludge processing business is 34 billion Euro/y. The project will have a large impact on the sludge handling procedures by sharply decreasing disposal costs. The sludge production is expected to increase with 2%/yr because of more stringent treatment processes and larger population connections to the sewage system._x000D_Energy derived from organic sludge in sewage treatment plants is renewable and CO2-neutral with the SCAR system._x000D_Currently during anaerobic digestion only half of the carbon in the sludge is converted into methane and carbon dioxide, supplying a maximum of 40% of the energy needs of the STPs. After digestion the reCOder is dewatered followed by transmission to agriculture (32%), composting (13%), land-filling (25%), incineration (13%) and other routes (17%). _x000D_SuperCritical Aqueous (Water) Gasification or Reforming (SCAR) is a new technology for producing valuable and clean hydrogen and methane containing gas from moist/wet biomass and sludge._x000D_Water in its critical state, in particular at 600C and 30 MPa (300 bar) is a powerful oxidant for carbon-containing substrates. With SCAR at high T and P water is cracked and C is combusted to form CO2, CO, CH4 and H2. The excess energy is enough to power the STP. The reaction converts 99.9% of the biomass within a few minutes into combustible gases. This means that only 20% of the energy content of the sludge is needed for its heating and pressurisation, while the reCOing 80% of the energy is available for external applications!_x000D_The SCAR process would negate the need for anaerobic digestion, sludge dewatering, sludge drying and incineration and bypass all these steps, as the primary and secondary sludge are directly converted into combustible gases by the SCAR process. This in turn lowers the STP costs, the cost of incineration the wet residue and land use considerably. In Europe sludges and rest biomass from industrial and agricultural production could meet 60% of the national goal for biomass-based energy of the year 2020; at the EU level the goal of the year 2010 could be fully met._x000D_Project objectives are: • development and testing of a slurry feed preparation process for sewage sludge. • development and testing of a high pressure sewage sludge pumping step of 350 bar. • development and measurement of the sewage sludge conversion process by SCAR at 300 bar and 600 °C using a pilot unit with 100 kg/hr slurry intake capacity (100 kWth) to produce a hydrogen-rich fuel gas. • techno-economic analysis of the process using Life-Cycle-Analysis techniques. • design of a 1 MWth demonstration unit for the conversion of sewage sludge to hydrogen rich fuel gas. The CO goal of the project is the reorientation of rest-biomass collectors and processors to produce a valuable green biomass slurry for hydrogen production using supercritical gasification. _x000D_The deliverables include a well-functioning pilot facility of 100 kWth including feed preparation and reforming, the pre-design of an industrial test facility of 1 MWth to be constructed in a follow-up project. _x000D_The economic benefits to consortium Ps is the placement of the SCAR technology at the STP sites for cost reduction and equipment sales. The economic benefits to the EU27 is a substantial saving of fossil resources used by the water treatment sector, the cheaper disposal of STP sludge, reuse of inorganic nutrients and export of SCAR units all over EU27 and the world. The proposed technology is 100% sustainable. The EU27 STP market is estimated at 6.000 units (one out of 4 STPs) and total sales of EUR 6000 million over a period of 15 years (400 Million Euro per year). Spin off into adjacent markets such as the food processing industry (vegetables, canning, slaughterhouses etc.) and chemical production sector could double the market. _x000D_The consortium consists of 7 Ps that cover the full spectrum of sludge treatment, energy conversion and nutrient recycling. The 7 Ps originate from 4 different EC countries. _x000D__x000D_
| Acronym | MOSS (Reference Number: 5877) |
| Duration | 01/05/2011 - 30/04/2014 |
| Project Topic | Europe has 25.000 larger STPs that consume large amounts of energy to purify sludges. This project demonstrates supercritical aqueous reforming (SCAR) of sludge at 600C and 300 bar and tail water nutrient recycling. The SCAR has an energy output of 150 kWth. A blue print is developed of 1 MWth. |
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Project Results (after finalisation) |
In the course of the pump development for this research project, we were actually able to elevate the limits set by us. The viscosity of the conveyed medium was increased even further. To facilitate this, the FELUWA check valves (ball valves) are further optimized in terms of flow. The success of this optimization was verified through various test in our own laboratory._x000D_The technical advantage of the increase of viscosity is that the medium now has a higher solids content. Through this the medium flow rate is drastically reduced with the same solids content, thus leading to a more economical energy consumption due to a smaller drive unit of the pump. |
| Network | Eurostars |
| Call | Eurostars Cut-Off 5 |
Project partner
| Number | Name | Role | Country |
|---|---|---|---|
| 7 | Callaghan Engineering | Partner | Ireland |
| 7 | Feluwa Pumpen GmbH | Partner | Germany |
| 7 | Hogeschool HAS Den Bosch | Partner | Netherlands |
| 7 | Recycling Consult B.V. | Coordinator | Netherlands |
| 7 | Sparqle International BV | Partner | Netherlands |
| 7 | University of Maribor | Partner | Slovenia |
| 7 | Waterschap Aa en Maas | Partner | Netherlands |