_ The Zero Emissions Strategy Conference

The Conference Podium, 18 September 1997

The Proposed ZERI Microbrewery
at The Earth Centre, UK

Case Study submitted to the conference by Stephen Bedford Clark

Rationale

The concept is to develop a waste utilisation process by the integration of several eco-technological mechanisms arranged in series, to absorb energy and nutrients for recycling within the system as saleable products. The waste stream chosen was that of an organic brewery waste effluent. The process has also been designed to consider land space restrictions and geographical climate conditions within the United Kingdom

Introduction

The Zero Emission Research Initiative (ZERI) is a global research project co-ordinated by the United Nations University (UNU) , dedicated to the research and demonstration of zero emission industries. The Microbrewery constitutes a partnership between The Earth Centre and the UNU and is recognised as one of the European pilot plant's for the Brewery-Aquaculture-Greenhouse (BAG) sub programme.

Aims & Objectives

The Microbrewery will be a 'State of the Art' facility incorporating a small beer production unit, algae cultivation, enclosed freshwater fish farming and hydroponic horticulture. The principle aim of the Microbrewery is to provide a practical demonstration of a zero-emission production process, generating a wide variety of marketable products in an accessible, entertaining manner, whilst complementing and supporting the visions and values of The Earth Centre.

The principle objectives are to demonstrate:

The utilisation of organic waste streams and the amalgamation of productive sub- systems for research and refinement of the overall process over a three year period.
To develop a process for technological transfer to urban zones with restrictive and premium valued land space and achieve effective:
- Ecological filtration
- Product diversification
- Commercial viability
- Zero waste outputs
To apply this process to a temperate European climate
To promote best environmental practice in industrial processing.
To convey this process as an interesting visitor exhibit to the general public and the dissemination of research data to the UNU for future CD-ROM educational materials.
To research and identify species suitability to the system with relevance to the saleable product and local market demand
To utilise sustainable techniques in the concentration of food productive systems and realise reasonable stocking levels without the need of chemicals or artificial - feed or fertilisers.

Current Status (1997)

The feasibilty phase of the Microbrewery project is now complete and consisted of a series of planning meetings with representative input from:

Hull International Fisheries Institute - Aquaculture
Kings College, London - Algae production
Horticulture Research International - Hydroponic Horticulture
Sheffield Hallam University - Research Co-ordination
Independent brewing consultants - Brewery design <
Letts Wheeler - Architectural requirements

This has resulted in a modelling and collation programme of relevant data to a systematic 'Statement of Need' compiled for integration into The Earth Centre construction programme. The Microbrewery is intended to commence operation by Autumn 1998.

The Process

The three recognised waste streams in activity order are as follows:

SOLID
Spent grain » Mushroom cultivation » Composting » Land remediation

LIQUID

Hot waste liquid » Heat extraction »

Algae production »

Freshwater fish culture »

Hydroponic horticulture »

Outer building reed bed water polishing

GASEOUS

Waste gases » Hydroponic plant feed

Description of main activities

Microbrewery

The Microbrewery element consists of a five batch brewery ( 2 brews per week) producing five barrels of beer per brew. (Approx. 820l ) The waste water ( with a Biochemical Oxygen Demand (B.O.D) up to 1800 mg/l ) generated by the brewing process is around five times the beer output (Approx. 4100 l ), with the other wastes being 96 kg of spent grains and 7 kg of yeast per brew. Approximately 500,000J of energy is available for re-use and 26m3 of Carbon Dioxide.

Algae Bio-reactor The liquid waste will be largely channelled into a Algae Bio-reactor, an intensive algae production system where the resultant medium can be utilised as a fish feed. The algae production reduces the B.O D. sufficiently to enable the output water to be of sufficient quality for fish culture.

Design specifications for optimum internal environment

Temperature : 18-25 C
High Light Level
High B.O.D (may still require additional nutrient supplement)

Freshwater fish culture The Aquaculture element will principally culture Tilapia, a native African herbivore which has increasing market value in the U.K. The fish will be cultured in rows of hanging bags of water stacked three tiers high. Stocking densities of up to 30 kg/m2 will be practised to maximise production without compromising overall fish welfare. Feed requirements for the Tilipia will be supplied by modules within the microbrewery, particularly the brewery waste, algae and horticulture waste.
Design specifications for optimum internal environment:

Temperature : Optimum 25C
Oxygen : Medium - High (Dependant on flow and temperature)
Water : 0.5 l / min / kg fish biomass

Hydroponic Horticulture The waste water from the aquaculture module will contain Nitrogen and Phosphorous, released in fish excreta and leached out of uneaten food. These wastes will be used as an organic fertiliser for hydroponic crops particularly tomato. Hydroponic horticulture will also utilise the majority of Carbon Dioxide produced during the brewing process.

Design specifications for optimum internal environment (Tomato):

Temperature : 12-20 C
Light : High
High ventilation
Carbon Dioxide : Enrichment up to 1000 ppm (During daylight hours)
Water : 2.7 - 11.25 l/m2/day (During daylight hours)

Mushroom Culture The solid brewery waste is an excellent medium for mushroom cultivation. Two varieties have been suggested as particularly suitable being Hericium ecrinaceus (Monkey Head Mushroom) and Lentinus Edodes (Shiitake).

Design specifications for optimum internal environment:

Temperature: 12-33C Minimum 10C
Humidity: Optimum 65% Range 60-80%
Little Ventilation
Low Light level

Practical considerations

Size & Location:

The energy efficient building will be hopefully located into a hillside, with a south-westerly facing aspect. The total internal floor surface will be 150m2.

Space requirement for main activities

Brewing @ 30 m2
Algae production @ 10 m2
Aquaculture @ 50 m2
Hydroponic horticulture @ 40 m2

Automated Environmental Management System:

A central dedicated computer network will be installed to monitor, control and attain an optimum integrated environment for each main activity.

Quantity of goods produced (Estimated)

Beer : 10 Barrels per week
Fish : 60m2 at 30 kg/m2 : Annual harvest : 4 tonnes
Hydroponics : 2000 kg of tomatoes plus 840 kg waste plant matter
Mushrooms : 20/30% of total substrate weight

Contributor

Stephen Bedford Clark held the post of Director of Freshwater Ecology at The Earth Centre for a period of 2.5 years. He has also developed Gunter Pauli's concept of a ZERI research initiative at The Earth Centre and over the past two years has continued to co-ordinate the project. His previous background has been in the field of freshwater aquaculture, designing and operating fish production units in the USA and Europe. Stephen is particularly interested in innovative fish species for human applications and ecological systems, particularly with respect to their role in sustainable development. Address: 7, Ballam Avenue, Scawthorpe, Doncaster, South Yorkshire, United Kingdom DN5 9DY. sbc@fishace.demon.co.uk
http://www.fishace.demon.co.uk

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