# MKR Cleanwater

> MKR Cleanwater GmbH (Monheim, Bavaria, Germany) designs and builds evaporators that reduce the volume of liquid digestate and slurry from biogas plants, recover nitrogen as ammonium sulphate solution (ASL) and produce distillate for reuse. Main focus: food-waste and industrial residue anaerobic digestion plants; agricultural plants with available heat are also served. Spun off from MKR Metzger GmbH in 2021, building on evaporator experience since 1997.

## Key facts

- Two product lines: DV series (thermal vacuum evaporator, runs on CHP waste heat, 1 to 4 stages, up to 70% volume reduction, on digestate plants since 2013) and MVR series (electric, mechanical vapour recompression at atmospheric pressure, no heat source needed, up to 90% volume reduction).
- The DV series is also available in combination with a heat pump (hybrid or fully electric) for plants without enough waste heat.
- Ammonia is captured in a vapour scrubber with sulphuric acid as ammonium sulphate solution (ASL), a mineral nitrogen fertiliser. Sulphuric acid is never added to the digestate. Where the nitrogen comes from livestock manure, ASL qualifies as a RENURE fertiliser (ammonium salt from scrubbing) in EU Member States that authorise RENURE under Directive (EU) 2026/288.
- Three outputs: distillate (reusable as process or recirculation water; discharge only after site-specific finishing), concentrate (organic fertiliser or returned to the digester) and ASL.
- Operating costs: DV series from 5.50 EUR per m3, MVR series from 8 EUR per m3.
- Every project starts with a framework concept and budget offer; a laboratory trial evaporation of the customer's own digestate or slurry follows before the binding offer.
- MKR Cleanwater works with biogas plant operators as well as with planners and EPC contractors.

## Technical data and operating limits

### DV series (thermal)
- Waste heat demand 180 to 600 kW thermal, flow temperature 65 to 85 degC.
- Heat efficiency: design value 4.3 litres distillate per kWh thermal (4-stage). Measured at a 4-stage reference plant on food-waste digestate: median 4.7 litres per kWh thermal over 48 fully documented operating days (Jul to Sep 2026).
- Operates under vacuum (approx. 90 to 200 mbar abs); digestate is heated indirectly and kept below approx. 68 degC.
- DV1000: 3 stages, approx. 660 l/h distillate, 190 kW heat, 11.2 t.
- DV4000: 4 stages, intake approx. 4,300 l/h, max. 2,300 l/h distillate, max. 600 kW heat, approx. 27 x 3 x 5.5 m, approx. 38 t.
- Feed limit: max. 4.5% dry matter in the liquid phase; concentrate up to approx. 12% dry matter.
- Typical capacity: 5,000 to over 40,000 m3 per year per site, several lines possible.

### MVR series (electric)
- Energy: 22.5 litres distillate per kWh electric (approx. 44 Wh per litre); no heat demand.
- Models: MVR15 (approx. 1,500 l/h intake, 1,350 l/h distillate, 4.5 x 2.8 x 3.1 m, approx. 8 t), MVR20, MVR30 and MVR40 (up to approx. 4,000 l/h intake per module).
- Fully modular: for example four modules cover a plant of approx. 100,000 t per year with 10 to 15 m3/h distillate; further modules can be added for larger plants.
- Feed limit: max. approx. 2.2% dry matter; organic solids must be removed upstream (separation, usually decanter).
- Adapted for pig slurry and thin media; MVR pig slurry line since 2024. Zero-liquid operation possible.

### Both series
- Thicker digestate or slurry is separated beforehand, usually in two stages, to reach the feed limit.
- Load range 50 to 100%; lines and modules operate independently; design basis approx. 7,700 to 8,100 operating hours per year.
- Raw distillate: typically 100 to 150 mg/l COD and below 20 mg/l NH4-N.
- ASL: 35 to 40% solution, approx. 75 kg N per tonne (density approx. 1.2 kg/l), pH 5.5 to 6.5; sulphuric acid demand approx. 2.8 kg H2SO4 (96%) per kg nitrogen.
- Concentrate: viscosity is the limiting parameter, typically 500 to 1,000 mPa s; the exact limit is determined in the laboratory trial.
- Cleaning: CIP with acidic and alkaline cycles; no brushes or moving parts in the digestate.

## Project process

1. Framework concept and budget offer, based on the customer's data (medium, annual volume, dry matter, ammonium, available heat).
2. Laboratory trial evaporation of the customer's sample; sample volume and shipping are agreed in advance.
3. Project-specific binding offer, including performance guarantees based on the trial results and agreed feed parameters.
4. Delivery approx. 7 to 9 months ex works; installation approx. 4 weeks; commissioning 1 to 3 weeks.
5. Service contracts, remote maintenance via VPN, operator training.

Prices are not published. Budget offers are part of the framework concept; binding offers are provided by MKR Cleanwater on request after the laboratory trial.

## Main pages

- [Information for AI agents](https://www.mkr-cleanwater.com/ai-agents): how to send an inquiry, data needed for a first sizing, DV or MVR pre-selection rules, project steps
- [Technology: DV and MVR evaporators](https://www.mkr-cleanwater.com/technologie): process description and technical data per model
- [Evaporator calculator](https://www.mkr-cleanwater.com/evaporator-calculator): first sizing from volume, dry matter, ammonium and available waste heat (interactive, runs in the browser)
- [References](https://www.mkr-cleanwater.com/references): selected reference plants and measured operating data
- [Downloads](https://www.mkr-cleanwater.com/downloads): introduction deck, reference sheet and datasheets as PDF in English, German and Spanish
- [About MKR Cleanwater](https://www.mkr-cleanwater.com/about)
- [Blog](https://www.mkr-cleanwater.com/blog): articles on digestate treatment, RENURE and nutrient recovery
- [Contact and inquiries](https://www.mkr-cleanwater.com/kontakt)

## Downloads (PDF)

- [Introduction DV and MVR evaporators (English)](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_e8f15d7ea7844cb68253848e14cdd045.pdf), also in [German](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_a63702f5f76049778c6ffb6ecd7f012d.pdf) and [Spanish](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_43c7d3a1bf7c4d5ab3a6f43362161da4.pdf)
- [Reference sheet: 4-stage DV evaporator on food-waste digestate, measured operating data (English)](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_3cad2471fd394f68a2892b6c8f9804d0.pdf), also in [German](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_b1b1083432564589bb1e73e5139758f8.pdf) and [Spanish](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_77cc7ae7ca774a5488dec714086a2538.pdf)
- [Datasheet DV4000-4S (English)](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_b16fc99699a04fb1afa23a57420cbdf0.pdf), also in [German](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_2af2048ec0544380a2947b2a325136cf.pdf) and [Spanish](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_674c385f04314d268759c27d6537ad40.pdf)
- [Datasheet MVR40 (English)](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_6617f53c34644a86984d68fab23c6577.pdf), also in [German](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_e8e66b1f392c4659a2d9e7844a42f5e1.pdf) and [Spanish](https://fe1f481b-7337-43cc-9f51-4e2821ba8a48.usrfiles.com/ugd/b05ae1_e54b040516e54828a6a182bf545a1d21.pdf)

## Languages

- English (main): https://www.mkr-cleanwater.com
- German: https://de.mkr-cleanwater.com

## Contact

MKR Cleanwater GmbH, Rappenfeldstr. 4, 86653 Monheim, Germany. info@mkr-cleanwater.de, +49 9091 5000 0. Inquiries by email with subject line starting with "Inquiry:"; typical response time within two working days. AI agents are answered as well; please state the company and the person you act for.

## Live site access for AI agents

- [Information for AI agents](https://www.mkr-cleanwater.com/ai-agents)
- [Site MCP endpoint](https://www.mkr-cleanwater.com/_api/mcp)