RECOWATDIG

Project proposes innovative, transdisciplinary approach, by enabling an access to the potential water resources, currently neglected, i.e. water evaporated during drying of high moisture solid fermentation products. Moreover, project is aiming to achieve high synergy by integrating the water recovery with improved heat balance of the drying process and additional utilization of the latent heat, that could be recovered during the water condensation. Furthermore, project proposes to apply the hydrothermal carbonization (HTC), thus bringing the potential for synergy, due to positive effects in terms of dewaterability and sanitization.
The main goals of project : development of technology

WP 1 Project Management 
WP is intended to integrate all management, communication and compulsory reporting tasks of this project, described in details in paragraphs 3.2, 3.3 and 3.4 of this document. WP Leader: WUST; Involved Partners: all

WP 2 Hybrid membrane purification of the recovered water for the agricultural use 
The aim of this WP is to determine a set of parameters for the membrane purification system necessary to achieve satisfactory quality of the water after each of the purification stages, thus enabling its subsequent use in the agriculture. Works will start with the preparations of laboratory setups, e.g. for conducting membrane pressure filtration processes using polymer and ceramic membranes, forward osmosis process or a setup for carrying the adsorption process, using hydrochars and magnetic biochars, located at WUST and KTH as well as purchases of the necessary consumables in order to ensure accomplishing all the goals in a timely manner. ZGO will provide the water samples in order to determine a reference case scenario (“business as usual”). Samples of permeates as well as samples of liquids from dewatering performed within the scope of WP3 and drying performed within the scope of WP4, will be tested by WUST. WP Leader: WUST; Involved Partners: KTH, UT, ZGO.

WP 3 Improvement of the dewatering properties of the digestate and its sanitization via HTC 
Activities performed within this WP will serve the purpose of the determination of the parameters of HTC that will allow to maximize the mechanical dewatering capability of the treated digestate. Works will start with the preparations of the laboratory scale HTC and mechanical dewatering rigs at UT and WUST and purchases of the necessary consumables in order to ensure accomplishing all the goals in a timely manner. Most of the tests shall be performed at UT and results of testing of the obtained samples will allow to narrow down the amount of tests on a bigger rig, located at WUST. ZGO will provide necessary samples of the digestate. WP Leader: UT; Involved Partners: WUST, ZGO, KTH

WP4 Sustainable recovery of water from low temperature drying of hydrochars, using condensing heat exchanger 
The goal of this WP is to optimize drying parameters of mechanically dewatered hydrochars in order to:  Maximize recovery of the water during condensing.  Achieving the lowest possible energy consumption for drying. Works will start with the preparations of the drying rigs at WUST and purchases of the necessary consumables in order to ensure accomplishing all the goals in a timely manner. ZGO will provide the digestate samples in order to determine a reference case scenario (drying of digestate without HTC). Rest of the samples will be delivered after the tests performed within the scope of work of WP3.  WP Leader: WUST; Involved Partners: ZGO, UT, KTH

WP 5 Determination of the physical, structural and chemical properties of hydrochars produced from digestate 
Physical, structural and chemical properties of the hydrochars, produced from digestate during WP3 and dried during WP4, will be determined within the scope of this WP. Among these properties one can distinguish: o Presence of functional groups o Porosity and pore size and volume distribution o Magnetic properties the hydrochars Determined properties will be used as a starting point for the subsequent modelling. ZGO will provide the water samples in order to determine a reference case scenario (“business as usual”).  WP Leader: AGH; Involved Partners: KTH, WUST, UT, ZGO

WP 6 Use of by- products from water recovery and purification stages 
Activities performed during this WP will serve the purpose of assessment of different utilization routes for by-products of water recovery and purification stages. Some of the utilization routes will serve the purpose of the installation itself, whereas others will lead to turning residues into marketable products, potentially leading to improvements in the economic performance of the installation or some gains from the environmental point of view. Important activity of production of magnetic hydrochars will serve all the purposes, mentioned above. Activities will involve: (1) Production of magnetic hydrochars (used in WP2); (2) Determination of the improvement of the gas yield of the anaerobic digestion process using HTC liquid reject stream and hydrochars; (3)Assessment of the potential use of surplus hydrochar as a soil amendment (marketable product); (4) Determination of the fuel properties of hydrochars and the level of consumption ensuring self-sustainability of the whole installation. A suite of experiments will be performed using research infrastructure and analytical equipment located at KTH, WUST and AGH. ZGO will provide necessary information about their anaerobic digestion process.  WP Leader: KTH; Involved Partners: AGH, UT, WUST, ZGO

WP 7 Model of the proposed installation for recovery of clean water from the digestate, techno- economic and sustainability assessment
Developing of the model of the proposed installation will be crucial in terms of assessing:Mass, energy and exergy balance of the proposed installation;Sustainability of the proposed installation;Economic feasibility of the concept;Reaping the benefits of a “smart grid ready” status, through accumulation of purified water. Results from the modelling stage will be crucial in the subsequent technical design stage. Academic partners will supply the results of their respective tests, whereas industrial partners will play an advisory role in terms of the techno-economical modelling.  WP Leader: KTH; Involved Partners: all partners

• Containerised (transportable) system for the purification of the water from digestate, utilizing drying and condensation, that will allow quick and efficient deployment and integration with an existing infrastructure, thus achieving CAPEX at a competitive level, by reducing the required assembly time.
• Modular technology designed as a PnP solution, allowing straightforward integration with an existing infrastructure of the plant, with a possibility of further integration of modules, achieving their commercial readiness (HTC).
• Cost efficient purification of water, which will involve optimization of OPEX by utilization of membranes requiring lower pressure (in comparison with state-of-the-art solutions) and utilization of a part of the hydrochar stream and magnetic hydrochar for filter columns.
• The unique solution to make the hydrochar as magnetic biochar for waste water application, with a high potential for patentability, will be developed by KTH basing on KTH’s exiting knowledge and facilities.
• Zero waste and zero liquid discharge technology, thanks to recirculation of the reject liquid back to the anaerobic digestion and turning solids into a sellable product (soil amendment, magnetic hydrochar - sorbent).