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A sustainable solution to resource recovery. Energy and Phosphorus Recovery from Municipal Sludge BHSL Hydro
A sustainable solution to resource recovery.
Energy and Phosphorus Recovery from Municipal Sludge
BHSL Hydro
Sewage Water
Dry Solids
1. Sludge Dewatering Solids
Dry Solids In Water Out
Heat In Dry Solids Out
2. Drying
6. Phosphorus Recovery
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ProcessEnergy & Phosphorus Recovery from Municipal Sludge
Four Global ChallengesWaste production is increasing while land application of agricultural and municipal sludges is being restricted due to concerns of potential contamination. Soil degradation is reducing the land available to feed the growing population. Energy consumption has required us to develop sustainable sources of fuel but it will surprise many to learn that phosphorus availability is an even greater problem. Recent estimates for when peak phosphorus production will occur vary between 2035 and 2075. Oil can be replaced with renewable energy whereas there is no substitute for phosphorus in food production. Phosphorus cannot be produced or synthesized in a laboratory. Quite simply, without phosphorus, we cannot produce food.
Phosphorus Recovery from Municipal Waste Since 2005 BHSL Hydro have designed and delivered systems that efficiently convert low calorific value manure into useful heat, or heat and electricity (CHP) on poultry farms. Innovative design and sophisticated combustion technology is at the heart of our patented system. The solution is well proven and has been designed specifically for use on a small scale with remote technicians to monitor the ongoing efficiency and compliance of the process. This technology breakthrough is now available to address the problem of municipal sludge.
Our solution reduces the dependancy on land spreading municipal wastewater sludge (sometimes called biosolids) which may contain harmful metals and bacteria and contribute to soil degradation. We utilise low temperature thermal oxidation to mineralise the organic nutrient content. The resultant ash is ideal for phosphorus recovery as it is easily transported and can be converted into high grade phosphoric acid acid or used as a fertiliser ingredient. Our solution has significant advantages over traditional treatments for municipal sludge such as lime stabilisation, anaerobic digestion or thermal drying.
Benefits of Energy & Phosphorus Recovery
• Reduce or end the practice of land spreading biosolids / municipal waste water sludge:
– Prevent human exposure to Pathogens such as E. coli
– Prevent metal contamination of soil
– Prevent pharmaceuticals and personal care products (PPCPs) contamination
– Protect food production brands from the negative publicity arising from contamination scares
• Extraction of valuable phosphorus as technical grade phosphoric acid acid or use as a fertiliser ingredient
• Energy generation for CHP applications
• Available in a variety of plant sizes to minimise sludge transportation
• Designed and remotely operated to exceed compliance requirements
1. Sludge Dewatering
A variety of sludge dewatering technology can be used and sites generally have existing solutions. BHSL Hydro recommend dewatering to produce 23% dry solids or more.
2. Drying An efficient drying process further increases the dry matter content to 50%-60%. This process uses heat from the combustion of dried sludge making it energy neutral. If electricity generation is also required then the drying system is operated using low grade heat to maximise efficiency. If an existing drying system is already in place then BHSL Hydro can assess it for suitability.
3. Energy Recovery The BHSL Hydro energy recovery process uses low temperature thermal oxidation to recover the thermal energy in the sludge and use the energy to meet heat or electricity generation demands. The municipal sludge is converted to an inert, fine ash with zero organic content. This ash is approximately 5% of the volume of untreated municipal waste (3% dry solids) making it convenient to transport.
The energy recovery process is self sustaining after startup, and if a Combined Heat and Power (CHP) plant is installed then the process is a net generator of electrical energy for use on site or export to the grid.
4. Ash Collection Ash is transported to a central facility for economic recovery of Phosphorus. As the ash is a small fraction of the initial sludge the transportation burden is reduced compared to spreading sludge on land.
5. Phosphorus Recovery The phosphorus has been mineralised at a low temperature, making digestion with sulphuric acid more efficient and producing technical grade phosphoric acid. Phosphoric acid has many uses in industry, including detergents and has an established market value.
Central processing can also avail of future improvements in recycling technology such as the recovery of metals. The solids remaining after phosphorus recovery are safely land-filled, protecting agricultural land from soil degradation and food brands from the potential damage caused by contamination.
Alternately the ash may be used as a fertilsier ingredient, with Phosphorus and Pottassium properties.
Fluidised sand
Air recirculation
Air and biomassquantities control heat output
Hot gas used for heating
3. Continuous combustion
2. Start up
Diesel burner raises bed temperature
4. Ash Collection
5. Phosphorus Recovery
3b. Continuous Energy Recovery
Air and biomassquantities control heat output
Hot gas used for drying
Air recirculation
Diesel burner raises bed temperature
3a. Energy Recovery Startup
Dry Solids In
Dry Solids Out
Dry Solids
Heat In
Water Out
2. Drying
1. Sludge Dewatering
Sewage Water
It is estimated that we will have mined half of the planets phosphate rock reserves within the next 18 to 58 years.
In the past century waste production has increased 10x. By 2025, it will double again.
Phosphorus
Waste
By 2050, world energy consumption is expected to increase more than 55%.
25% of agricultural land is degraded and climate changes are compounding this problem.
Energy
Agriculture
25%
55% 50%
100%
Dewatering
Drying
Energy Recovery
Ash Collection
Phosphorus Recovery
Electricity Generation
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Containerised Format 300 - 500 Energy Centre Format 750 - 5000Ideal for smaller sites Choose between heat only combustion units
or a CHP unit that can generate electricity
Model name 300 500
Plant Footprint1 m2 58 115
Process Input
Guideline People Equivalent PE 29,000 48,000
Cubic Meters of Sewage / Day @ 3% Dry m3 72 120
Tonnes Dry Solids Equivalent per Annum tds/a 72 1,200
Dewatering
Dry Matter Percentage Input % 3 3
Dry Matter Percentage Output % 22 22
Electrical Energy Required / Hour kW 3 5
Drying
Moisture Content Presented % 78 78
Moisture Content After Drying % 40 40
Water Removed / Annum m3 2,087 3,455
Electrical Energy Required / Hour kW 15 25
Thermal Energy Required / Hour2 kWth 261 432
Energy Recovery
Dried Sludge Processed / Annum3 Tonnes 1,208 2,000
Thermal Energy Created / Hour4 kWth 301 499
Electrical Energy Required / Hour kW 15 25
Gross Electrical Generation / Hour (CHP)5 kW n/a 55
Quantity of Ash Produced / Annum6 Tonnes 225 373
Phosphorus Recovery
Phosphorus (P) Recovered per Annum7 Tonnes 12 19
CHP Energy Balance (Optional)8
Net Electricity Generated kW n/a Self Sufficient
Model name 750 1200 1400 2500 5000
Plant Footprint1 m2 383 484 565 On Enquiry On Enquiry
Process Input
Guideline people Equivalent PE 72,000 116,000 136,000 240,000 480,000
Cubic Meters of Sewage / Day @ 3% Dry m3 180 290 340 600 1,200
Tonnes Dry Solids Equivalent per Annum tds/a 1,800 2,900 3,400 6,000 12,000
Dewatering
Dry Matter Percentage Input % 3 3 3 3 3
Dry Matter Percentage Output % 22 22 22 22 22
Electrical Energy Required / Hour kW 7 12 14 25 50
Drying
Moisture Content Presented % 78 78 78 78 78
Moisture Content After Drying % 40 40 40 40 40
Water Removed / Annum m3 5,182 8,348 9,788 17,273 34,545
Electrical Energy Required / Hour kW 37 60 71 125 249
Thermal Energy Required / Hour2 kWth 648 1,044 1,223 2,159 4,318
Energy Recovery
Dried Sludge Processed / Annum3 Tonnes 3,000 4,833 5,667 10,000 20,000
Thermal Energy Created / Hour4 kWth 748 1,205 1,413 2,493 4,987
Electrical Energy Required / Hour kW 37 60 71 125 249
Gross Electrical Generation / Hour (CHP)5 kW 82 193 226 481 962
Quantity of Ash Produced / Annum6 Tonnes 559 900 1,056 1,863 3,726
Phosphorus Recovery
Phosphorus (P) Recovered per Annum7 Tonnes 29 46 54 96 192
CHP Energy Balance (Optional) 8
Net Electricity Generated kW Self Sufficient 61 70 206 414
Notes
*1. Plant footprint is a guide. A general assembly layout is required for each site.
*2. Thermal energy required for drying will depend on local conditions.
*3. Quantity of sludge to be processed for energy recovery is provided as an illustration, the precise quantity will be determined by the type of dewatering process used by a site and the calorific value of the sludge.
*4. Nominal heat output under steady conditions and allowing heat output tolerance of +/- 10%.
*5. Optional CHP electrical generation is available depending on site requirements.
*6. Ash and phosphorus production will depend on an analysis of the sludge to be processed.
*7. A central phosphorus recovery plant is required to accept ash from processing sites or the ash can be used as a fertliliser ingredient.
*8. Energy balance figures are provided as a guideline only, subject to confirmation based on firm enquiry and site analysis.
We reserve the right to modify this technical data without notice.
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Onsite Energy Recovery
Contacts for further information
www.linkedin.com/company/bhslwww.twitter.com/bhslhydrowww.facebook.com/BHSLHydro.ie/
Ireland: +353 69 85926UK LoCall: 0844 5447727USA: +1 443 603 0316Email: [email protected]
Address:Kantoher Business ParkKilleedy, BallaghCo. LimerickV42 RY96Ireland
BHSL Hydro
