Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 2/9

1. TECHNOLOGY DESCRIPTION

GW Dryer is a novel drying technology for converting liquid foods and other related biomaterials into

powders, flakes, or sheets with added value (see Fig. 1).

Principle used

GW Dryer utilizes hot water as the heat transfer medium to dry a wide variety of products carried by a belt

conveyor.

How it Works

A liquid or puree is evenly applied on a moving, food grade belt (wet biomass in thin layer, 40 – 300 µm). Hot

water below the moving belt is used as the heat source. Heat transfer is achieved by convection, conduction

and radiation through a polyester Mylar belt from the body of hot water to the product to be dried. Air

circulation above the belt removes moisture from the drying tunnel. The dried product is cooled (cooling

water) and removed from the belt.

GW Dryer is a modular technology and 5 models are available (GW Dryer is expandable from 1 to 5

modules). Model 2 (Size (L X W X H) = (14.94 x 2.44 x 2.59) m, belt length 112 feet (34 m), heating surface

around 17,5 m2) is the object of this EU ETV verification.

Figure 1. Conceptual design of the GW Dryer

RINA, commissioned by the Institute for Agricultural and Fisheries Research (ILVO), has verified the

performance claim of the technology “GW Dryer” according to the relevant procedures for EU ETV as for

GVP Version 01 - July 7th, 2014 and the requirements set in the Specific Verification Protocol N° 2015-DG-

MP-141, Revision N° 00.

ILVO, according to the objectives of the FP7 Noshan project (http://www.noshan.eu) is investigating the

processes and technologies needed to use food waste for feed production at low cost, low energy

consumption and with maximal valorization of starting wastes. In this context moisture control and

stabilization technologies are also analysed, including the “GW Dryer” technology.

The Noshan project has received funding from the European Union’s Seventh Framework Programme for

research, technological development and demonstration under grant agreement n° 312140

G3 Enterprises (G3) is the owner of the technology “GW Dryer” (formerly known as the Refractance

Window® Dryer). G3 authorized the verification of the environmental performance of the GW Dryer as

proposed by ILVO according to the EU ETV Programme.

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 3/9

2. APPLICATION 2.1 MATRIX Liquids, slurries, pastes. 2.2. PURPOSE To dry wet products (liquids, slurries, pastes) into a dry, stable products. 2.3 CONDITION OF OPERATION AND USE

GW Dryer is a continuous process. The wet liquids, slurries, pastes are applied in a thin layer: 40 – 300 µm

(Fig.2). Finished Product capacity: 5 – 50 (kg/h) is dependent on feed solids and process conditions. The

GW Dryer utilizes circulating hot water, usually at 95–97 °C and at atmospheric pressure, to carry thermal

energy to material to be dehydrated. However the actual product temperature during the process is usually in

the 60 - 70 °C range. More information about the condition of operation and use for the specific GW Dryer’s

application tested are available in table 5.

Fig.2: the thin layer of tested materials on the GW Dryer belt.

2.4 VERIFICATION PARAMETERS DEFINITION SUMMARY

The goals of this test are to verify the technology performance regarding the following aspects:

Thermal Efficiency of the GW Dryer. The evaporation of water from the product at the air–puree

interface constitutes a major part of energy consumption in RW drying1. For this reason the

verification activities focused on the “thermal efficiency” expressed as the ratio of the theoretical

thermal energy for drying the wet products to the actual thermal energy supplied for drying by the

heating unit (the efficiency of possible pre-heating steps as well the efficiency of the steam generator

are not included in the thermal balance. Air to remove moisture has not been considered in the

drying heat balance).

Ability of the GW Dryer to maintain color of initial feed material. GW Dryer can be used to gently

remove moisture from delicate products like anthocyanins and other natural colorants preserving the

natural color. The Color Loss parameter shows the ability of the GW Dryer to maintain color of initial

feed material.

Minimal Product Loss. The Solid Yield parameter shows the ability of the GW Dryer to perform the

drying process with a high percentage of the product recovered.

1 (Nindo et al., 2007) Refractance Window Dehydration Technology: A Novel Contact Drying Method - Drying

Technology, 25: 37–48, 2007

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 4/9

In table 1 a summary of the aspects covered by the verification and related performance parameters.

Table 1: Summary of the performance parameters

Aspect Related Performance Parameter (unit)

Thermal Efficiency of the GW Dryer

Thermal Energy consumption (kJ/kgH2O)

Thermal Efficiency (%)

Surface Evaporation capacity (kgH2O/ hm2)

Ability of the GW Dryer to maintain color of

initial feed material

Color Loss (%)

Extinction Value (EV) on a dry basis at (λmax)

Minimal Product Loss Solids Yield (%)

Dry Product Loss (%)

Feed material (kg / h)

Input’s moisture content (%)

Product material (kg / h) Product’s moisture content (%)

3. TEST AND ANALYSIS DESIGN

3.1. EXISTING AND NEW DATA

No existing data was submitted by the proposer. This ETV verification is based on new data collected by G3

Enterprises trough the GW Dryer (Model 2) available at the “San Joaquin Valley Concentrates” (SJVC),

wholly owned by E & J Gallo Winery. The test was performed on 28th of January 2016 in California (US) at

the following address: “San Joaquin Valley Concentrates”, 5631 E. Olive Ave. Fresno, CA 93727

G3 Enterprises, Inc., Delaware Corporation, located at 502 E. Whitmore Avenue, Modesto, California 95358

(“G3”) was in charge of planning, performing and reporting the testing activities (Test Body).

ROLE – TEST BODY LAST NAME FIRST NAME

TEST RESPONSIBLE BENAVIDES ALFONSO

INTERNAL AUDITOR ANDERSON STEVEN

3.2. LABORATORY OR FIELD CONDITIONS

The GW Dryer (Model 2) available at SJVC is a full scale / commercial application of the GW Dryer. SJVC is

a supplier of grape juice concentrates, natural colors, and grape seed extract to the food and beverage

industries. G3 Enterprises, Inc., Delaware Corporation, located at 502 E. Whitmore Avenue, Modesto,

California 95358 (“G3”) was in charge of planning, performing and reporting the testing activities (Test Body).

ROLE – TEST BODY LAST NAME FIRST NAME

TEST RESPONSIBLE BENAVIDES ALFONSO

INTERNAL AUDITOR ANDERSON STEVEN

The testing activities were conducted at the “San Joaquin Valley Concentrates’ (SJVC), 5631 E. Olive Ave.

Fresno, CA 93727, where the the GW Dryer (Model 2) is used to concentrate and dry natural colors. SJVC

operators and lab staff were involved in the testing activities under the supervision of the G3 test

responsible.

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 5/9

3.3. MATRIX COMPOSITIONS

Two types of Natural Color from Grape Skins (Anthocyanins) were tested:

- “Liquid Purple Grape” (Fig.3) and “Liquid Red Grape”

These tested products are natural colors produced from California grapes. They are concentrated and dried

in crystal form without the use of any carriers. The product is non-hygroscopic and readily soluble. The

materials tested are in line with the SVP.

Fig.3: Liquid Purple Grape

3.4. TEST AND ANALYSIS PARAMETERS

The list of parameters considered in the specific verification protocol is described in Table 2.

Table 2: Parameters considered in the specific verification protocol

Parameter (list of

parameters to be

considered in the

specific verification

protocol)

Value

at the 95% confidence

level

Existing legal

Requirements

and/or BAT

values

Test or

measurement

method(s)

Water Temperature

Inlet Temperature: 80-98

°C

Outlet Temperature: 80-

98 °C

Not applicable Electrical instrumentation

for Temperature: ifm

efector TD2817

Moisture content Finished product at 7%

moisture

Not applicable Thermogravimetric

analysis: Lab Equipment

for Moisture Measurement:

Mettler Toledo MJ33.

Water Flow To be determined during

testing

Not applicable Dynasonics (now Badger

Meter) DXNP-AHS-NN

Doppler/Transit Time Flow

Meter

Weight 50 – 100 kg/h wet feed @

~30% solids.

20 – 30 kgs/h of finished

product at 7% moisture.

Not applicable Weight of Barrels: Mettler

Toledo IND560

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 6/9

Color in finished

product (Extinction

Value Test)

EV @ pH 3.00 (λmax) USA: 21 CFR

73.250. Fruit

juice for color.

EU: EU

Commission

Regulation N°

231/2012

Extinction Value Test

Method at pH 3: λmax at

520 nm.

Spectrophotometer Hewlett

Packard 8453

3.5. TESTS AND ANALYSIS METHODS SUMMARY

During dryer operation one separate data collection events each lasting 2 to 3 hours was conducted.

1) Thermal Efficiency of the GW Dryer.

Measurement of heating water flow and temperatures: A doppler/transit-time wrap around flow meter was

utilized to measure flows on dryer hot water feed pipes. Local readout water thermometers were installed on

all hot water supply and return pipes from heat exchangers to dryer hot water reservoirs. Several reading of

each parameter were taken during the test period.

2) Ability of the GW Dryer to maintain color of initial feed material.

Samples were taken of the dryer feed material and the dryer product for each lot. Samples were then

analysed for color intensity on a dry weight basis using a spectrophotometer. Color Intensity was reported

using the Extinction Value Method with the units of “EV @ pH 3.00 (λmax)”. The color intensity “lost” across

the dryer was then be calculated from the color intensity method by looking at the delta before and after

drying and then dividing by the original color intensity, prior to drying.

3) Minimal Product Loss

Samples of product being fed and dried material being produced were taken to be analysed for moisture

content. The total amount of material fed to the dryer and the total amount of dried product was weighed at

the end of each test run.

3.6. PARAMETERS MEASURED

In addition to the performance parameters listed in section 2.4 above the following parameters were

measured and evaluated as part of the verification (table 3):

Table 3: Parameters considered in the specific verification protocol

Parameter (list of parameters to be considered in the

specific verification protocol)

Unit of measure

Duration of the process hours

Temperature of Feed to Dryer °C

Temperature of the product at the outlet °C

Water Temperature at 4 Inlets of Dryer °C

Water Temperature at 4 Outlets of Dryer °C

Flow Rate of Water at 4 Inlets of Dryer Liters/min

Humidity of Dryer Room %

Ambient Temperature of Outside Air C

Humidity of Outside Air %

Initial color in feed materials Extinction Value (EV) on a

dry basis at (λmax)

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 7/9

4. VERIFICATION RESULTS 4.1. PERFORMANCE PARAMETERS

In table 4 the verified performance is presented as a mean value together with the respective 95 %

confidence intervals and compared with the claimed performance.

Table 4. Claimed versus Verified Performance

Parameter Claimed Performance Verified Performance

Type of Input material ANTHOCYANINS (E 163)

Natural Color from Grape Skins

Two different types of input

materials have been tested:

Liquid Purple Grape

Liquid Red Grape

Thermal Efficiency of the GW Dryer

Thermal Energy consumption

Surface evaporation capacity

52-77%, (Nindo et al., 2007)

3320 – 4920 kJ/kgH2O

1.5 – 2.5 kgH2O/ hm2

63% [60 – 65]

3876 kJ/kgH2O [3715 – 4037]

3,2 kgH2O/ hm2

[2,6 – 3,8]

Color Loss (ability of the GW Dryer to

maintain color of initial feed material)

Extinction Value (EV) on a dry basis at

(λmax)

6%

20 – 23

10%

[0 – 21]

21,50

[21,38 – 21,75]

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 8/9

Solid Yield / Loss

Solids Yield : Product Solids (kg)/Feed

Solids (kg)

Dry Product Loss

Feed material

Input moisture content

Product material

Product moisture content

95 – 99,5 %

0,5 – 5 %

50 – 100 kg/h wet feed

~70% moisture

20 – 30 kg/h of finished product

product at ~7% moisture

100 %

[96,6 – 100]

0 %

[0 – 3,4]

87 kg/h

[74 – 99]

69%

[67 – 72]

28 kg/h

[27 – 30]

7,4%

[6,6 – 8,2]

Verified thermal efficiency (60 – 65%) is in line with the claimed range (52 – 77%) (see Table 4). It is

important to take in mind that many factors can influence the thermal efficiency performance (e.g thickness

and consistency at deposition, Nindo et al., 2007). The verified performance is thus related only to the

specific application object of verification. The verified average thermal energy consumption is 3876 kJ/kgH2O

with an average surface evaporation capacity of 3,2 kgH2O/ hm2

(based on a evaporation surface of the GW

Dryer of 17,466 m2), resulting higher than the claimed range

2 .

The test results show a color loss value slightly bigger than expected, however Extinction Value (EV) on a

dry basis at (λmax) of the products is in line with the expected performance.

The test results show that the drying process of the tested products do not involve any significant dry product

loss, with a solid yield bigger than 96,6% at the 95% confidence level. It means that the color intensity meets

the performance claimed.

4.2. OPERATIONAL PARAMETERS

Appropriate environmental and operational conditions were ensured for the test performance. See the details

in table 5. Air to remove moisture was not heated above hot water temperature, was kept as constant as

possible in all and lower than the product feed temperature over the duration of the test. It was not

considered in the drying heat balance.

Table 5. Operational Parameters and Environmental Conditions

Operational Parameters and Environmental Conditions Value

Duration of the process In average 148 min to treat

50 gallons ( 189,27 liters)

Temperature of Feed to Dryer after pre-heating 52°C

Environmental Conditions

T > 0 °C

2 The range claimed was probably too conservative. According to (Nindo et al., 2007) typical surface evaporation capacity is in the

range 1-10 kgH2O/ hm2

Verification Statement of “GW Dryer” – Version 0.2 ETV_08_VStatement (09/2015) page 9/9

Water Temperature at 4 Inlets of Dryer 96,5°C

Water Temperature at 4 Outlets of Dryer 95,5 °C

Flow Rate of Water at 4 Inlets of Dryer 223 Liters/min for each of

the 4 inlets

Temperature of Dryer Room 32 °C

Humidity of Dryer Room 54%

Ambient Temperature of Outside Air 10 °C

Humidity of Outside Air 50%

Initial color in feed materials: Extinction Value (EV) on a dry basis at (λmax) 23-27

4.3. ENVIRONMENTAL PARAMETERS The relevant environmental parameters are included as performance parameters as described in section 4.1

5. ADDITIONAL INFORMATION

Additional information can be found in the verification report.

6. QUALITY ASSURANCE AND DEVIATION

The test and verification activities were planned and undertaken in order to satisfy the requirements on

quality assurance described in the General Verification Protocol Version 1 developed for the EU ETV Pilot

Programme.

Test activities were undertaken by the Test Body G3. The test activities has been conducted under a quality

management system that follows the principles of EN ISO 9001 and it is judged that it fulfils the requirements

of the EU ETV General Verification Protocol (Chapter C.III).

An external review was performed for the specific verification protocol, the verification report and the

statement of verification by the technical expert Andrea Maffini.

7. REFERENCES (EU Environmental Technology Verification Pilot Programme) General Verification Protocol, version 1.1 of

07-July-2014

(Nindo et al., 2007) Refractance Window Dehydration Technology: A Novel Contact Drying Method - Drying

Technology, 25: 37–48, 2007