WO2006001689A1

WO2006001689A1 - Energy-saving combination

Info

Publication number: WO2006001689A1
Application number: PCT/NL2005/000413
Authority: WO
Inventors: Eleonoor Van Andel; Gatze Lettinga
Original assignee: Fiwihex BV
Current assignee: Fiwihex BV
Priority date: 2004-06-23
Filing date: 2005-06-08
Publication date: 2006-01-05
Anticipated expiration: 2006-12-23
Also published as: EP1758445A1; NL1026484C2

Abstract

The invention relates to a combination, comprising: at least one house with an outgoing fermentable waste flow and an outgoing waste water flow, at least one anaerobic waste fermentor with an ingoing waste flow and an outgoing fermentor gas flow; and at least one closed horticulture greenhouse, wherein the fermentable waste flow runs out into the anaerobic waste fermentor, the waste water flow and at least the carbon dioxide part of the fermentor gas flow runs out into the closed greenhouse, wherein condensed water and a heat flow from the closed greenhouse is supplied to the at least one house.

Description

ENERGY-SAVING COMBINATION

The invention relates to an energy-saving combination. It is for the good of the environment to make very sparing use of energy and to limit the emission of harmful substances . It is particularly important to limit the emission of carbon dioxide gas and thus prevent further intensification of the greenhouse effect on earth. Known measures for saving energy and reducing CO₂ emission are for instance the reduction in processes that are very wasteful of energy and the reuse of already produced material . The use of means of transport which emit less carbon dioxide is also being stimulated as alternative to means of transport which do have a high CO₂ emission. In the case of houses the use of durable materials and insulation of houses is stimulated. The use of energy-saving appliances is one of a series of measures aimed at decreasing CO₂ emission and reducing the consumption of energy. US-A-5 527 464 describes a combination wherein waste from a community is taken to a waste fermentor. The carbon dioxide and the water from the waste fermentor are supplied to, among others, an open horticulture greenhouse. The gas from the fermentor can be used to generate energy. It is now an object of the invention to provide an energy-saving combination which contributes^{" "}toward the above stated objectives. This is achieved with a combination according to the invention, comprising: - at least one house with an outgoing fermentable waste flow and an outgoing waste water flow, - at least one anaerobic waste fermentor with an ingoing waste flow and an outgoing fermentor gas flow; and - at least one closed horticulture greenhouse, wherein the fermentable waste flow runs out into the anaerobic waste fermentor, the waste water flow and at least the carbon dioxide part of the fermentor gas flow runs out into the closed greenhouse, wherein condensed water and/or a heat flow from the closed greenhouse is supplied to the at least one house. The fermentable waste flow from a house is usually removed via the domestic refuse to a central tip or incineration furnace. In some cases vegetables, fruit and garden waste are separated from the other domestic waste and processed separately at a central location. Water from shower and bath, water from the kitchen and water from the toilets is. normally carried via one sewage system to a central water treatment plant. In the context of the invention a house is understood to mean any building in which people and/or animals reside on regular basis, such as care centres, offices, shops, livestock accommodation etc. With the combination according to the invention these different waste flows are reused for the benefit of the at least one house. The fermentable waste flow, such as for instance vegetables, fruit and garden waste and the water from the toilets is fed to a waste fermentor, which produces an increased CO₂ content which is then^"in turn converted by the greenhouse, and in particular the crops cultivated therein. The plants evaporate much water in their metabolism which, after cooling, can be fed as condensed water again to the at least one house. The crops can in turn then be consumed by the residents of the houses. The waste water flow, which is also referred to as grey water flow and which is little-contaminated water, such as for instance from shower and bath, can then be used to irrigate the crops in the greenhouse. A preferred embodiment of the combination according to the invention comprises a gas turbine, gas motor or a high temperature fuel cell, which is placed in the fermentor gas flow and converts at least the combustible part of the fermentor gas flow into water vapour and carbon dioxide. In addition to carbon dioxide, the anaerobic waste fermentor also produces combustible gases, in particular methane. By now burning this combustible part of the fermentor gas flow, energy is created which in a preferred embodiment can be converted into electric power and can be supplied to the greenhouse and/or the at least one house. The combination according to the invention thus ensures that electric current is generated from the waste flow produced by the at least one house, which current can be reused by the at least one house. The use of a high temperature fuel cell, such as a melted carbonate, or solid oxide fuel cell, has the additional advantage of a higher efficiency and cleaner gas emissions . In yet another embodiment of the combination according to the invention, the heat generated by the gas turbine or gas motor is supplied to the greenhouse and/or the fermentor and/or the at least one house. When the combustible part of the fermentor gas flow is burned, much heat is created which can be used to hold the greenhouse at a temperature which enhances the growth of the crops or to hold the fermentor at the desired temperature so that the anaerobic conversion is maximized. The heat can also be used to heat the houses or provide them with hot tap-water. Another preferred embodiment of the combination according to the invention comprises a water-bearing soil layer or basin, wherein a heat flow from the greenhouse is supplied to the water-bearing soil layer. During the summer or during the day excess heat from the greenhouse can be supplied to the water-bearing soil layer, while in the winter or at night heat from this water-bearing soil layer or basin can be fed back for the purpose of heating the greenhouse and/or a house. In another embodiment, heat is exchanged between the water-bearing layer and the at least one house. The¹ water-bearing layer, which is comparatively cool in the summer, can thus also be used for instance to lower the temperature in the at least one house. Yet another embodiment of the combination according to the invention comprises cooling means, such as for instance a cooling tower, for the purpose of cooling the water-bearing layer. In a preferred embodiment, a photovoltaic layer is arranged at least partially on the at least one house for generating electricity from light. The thus generated electricity can be used during daylight to drive the different installations and to provide the houses with electricity. In addition, the electricity can optionally be stored for use during the night. This combination preferably further comprises a device for generating hydrogen using the photovoltaic electricity. This hydrogen can be readily formed from for instance the condensed water. This hydrogen can in turn then be used to provide energy. The hydrogen can for instance be used to propel a vehicle. It is further also recommended here to supply the hydrogen to the fermentor in order to convert the hydrogen ■into methane. The bacteria used will easily convert the hydrogen, in combination with CO₂, into methane. The advantage of methane is that it is more readily compressible and can thus be used more easily for vehicles or for storage in order to generate electricity again during the night. These and other features of the invention are further elucidated on the basis of the accompanying schematic diagram. The figure shows an exemplary embodiment of a combination according to the invention. The combination comprises at least one house 1 which discharges a fermentable waste flow 2 to a fermentor 3. This fermentor 3 is an anaerobic fermentor which emits a fermentor gas flow 4 as a result of the anaerobic fermenting process . This fermentor gas 4 contains, among others, CO₂ and methane gas. The fermentor gas is fed to a turbine 5 or a gas motor which here converts the combustible part of the gas flow into electricity 6, heat 7 and CO₂. The heat flow 7 is fed back again to fermentor 3 to thus hold this latter at the correct operating temperature. The gas 8 burned by turbine 5 or the gas motor, which now consists mainly of CO₂ and water, is fed to a cooler 9. The water in gas flow 8 is here condensed, and is then fed via flow 10 to a greenhouse 11. Being cultivated in the greenhouse is a crop which is stimulated to grow by means of an additional supply 10 of CO₂. Waste water 12 from house 1 is used to irrigate the crop. This waste water 12 consists substantially of bath and shower water. The crop grows under the influence of sunlight 13 incident upon the greenhouse 11. Excess heat 14 can be supplied from greenhouse 11 to a water-bearing soil layer 15 which can function as buffer for heat. The heat stored in this water layer can subsequently be supplied vie a heat flow 16 to greenhouse 11, in the case the outside temperature is low, and fed back again via a heat flow 17 to houses 1. Condensed water from greenhouse 11 can further be supplied via flow 18 to the at least one house 1.

Claims

1. Combination, comprising: - at least one house with an outgoing fermentable waste flow and an outgoing waste water flow, - at least one anaerobic waste fermentor with an ingoing waste flow and an outgoing fermentor gas flow; and - at least one closed horticulture greenhouse, wherein the fermentable waste flow runs out into the anaerobic waste fermentor, the waste water flow and at least the carbon dioxide part of the fermentor gas flow runs out into the closed greenhouse, wherein condensed water and/or a heat flow from the closed greenhouse is supplied to the at least one house.

2. Combination as claimed in claim 1, comprising a gas motor, gas turbine or a high temperature fuel cell, which is placed in the fermentor gas flow and converts at least the combustible part of the fermentor gas flow into substantially water and carbon dioxide.

3. Combination as claimed in claim 2, wherein the gas turbine generates electric current, which current is supplied to the greenhouse and/or the at least one_. house and/or the fermentor.

4. Combination as claimed in either of the foregoing claims 2 or 3, comprising a cooler for cooling fermentor gas flow flowing out of the gas turbine, wherein heat from the cooler is supplied to the greenhouse and/or the at least one house and/or the fermentor.

5. Combination as claimed in any of the foregoing claims, wherein heat generated by the gas turbine is supplied to the greenhouse and/or the fermentor and/or the at least one house.

6. Combination as claimed in any of the foregoing claims, comprising a water-bearing soil layer, wherein the heat flow from the greenhouse is supplied to the water¬ bearing soil layer.

7. Combination as claimed in claim 6, wherein heat is exchanged between the water-bearing layer and the at least one house.

8. Combination as claimed in claim 7, comprising cooling means, such as a cooling tower, for the purpose of cooling the water-bearing layer.

9. Combination as claimed in any of the foregoing claims, wherein a photovoltaic layer is arranged at least partially on the at least one house for generating electricity from light.

10. Combination as claimed in claim 9, comprising a device for generating hydrogen using the photovoltaic electricity.

11. Combination as claimed in claim 10, wherein the hydrogen is supplied to the fermentor in order to convert the hydrogen into methane.